HK1222618B - Stroller - Google Patents

Description

baby carriage

This application is a divisional application of the invention patent application with application number 201280053113.7. The date of entry of the original application into the Chinese national phase is April 28, 2014. The invention name of the original application is “Foldable baby stroller”.

Technical Field

The present invention relates to a baby carriage.

Background Art

Strollers that are formed by connecting left and right structural components of the stroller body with a linkage mechanism and can be transformed between an expanded and folded state are well known. In this type of stroller, the upper ends of the front and rear legs are connected to the front end of an intermediate linkage member called an armrest. The rear end of the armrest is rotatably connected to a handlebar, and the handlebar and rear legs are connected by an open/close locking mechanism. When the stroller is in the expanded state, viewed from the left and right sides, the armrests extend generally in the front-to-back direction of the stroller body, and the handlebars extend generally parallel to the front legs at a position rearward and away from the front legs (see, for example, Patent Document 1).

Patent Document 1: Japanese Patent Application Publication No. 2008-174016

Typically, the front wheels of a baby stroller are mounted on the front legs via a rotating mechanism centered around a vertical axis of rotation. Furthermore, in conventional baby strollers, to facilitate folding, the handlebars extend rearward, away from the front legs, and approximately parallel to the legs. Therefore, when applying force to the front and rear wheels from the lower portion of the stroller, near their ground contact surface, the user's force is transmitted through the handlebars to the lower portion of the stroller, allowing the front wheels to be pushed from a position rearward, away from the axis of rotation of the front wheels. In other words, the front wheels are pushed from a position rearward, away from the freely rotating front wheels, thereby enabling the stroller to be operated. However, because the front wheels often wobble about their axis of rotation, the front wheel's orientation can become unstable, both when moving in a straight line and when rotating, impairing the stroller's operability.

Summary of the Invention

In view of the above situation, one of the objects of the present invention is to provide a baby stroller that can maintain the folding function while improving the operability. Another object of the present invention is to provide a baby stroller that can simultaneously ensure bending strength and rigidity while providing a visual effect to the user.

The baby carriage of the present invention comprises a body (2), front legs (14), rear legs (15), a handlebar (30), an intermediate linkage component (16), a front linkage component (35), and a rear linkage component (36), wherein the front legs (14) are arranged on both sides of the body (2) in the left and right directions, and are provided with front wheels (22) which can rotate around a predetermined rotation axis (VA); the rear legs (15) are provided with rear wheels (26); the handlebar (30) is used to transmit the user's operating force to the body; one end of the intermediate linkage component (16) is connected to the upper ends of the front legs and the rear legs respectively and is rotatable, and the other end is connected to the handlebar and is rotatable; one end of the front linkage component (35) is located at a position closer than the connection point (33) between the connecting rod and the intermediate linkage component. 4) is connected to the handlebar at a lower position (37) and is rotatable, and the other end is connected to the front leg at a position (38) lower than the connection point (29) between the front leg and the intermediate linkage component and is rotatable; one end of the rear linkage component (36) is connected to the handlebar at a lower position (37) than the connection point between the connecting rod and the intermediate linkage component and is rotatable, and the other end is connected to the rear leg at a lower position (39) than the connection point (29) between the rear leg and the intermediate linkage component and is rotatable; by making the front legs, the rear legs, the handlebar, the intermediate linkage component, the front linkage component and the rear linkage component rotate relative to each other around each connection point, the baby carriage can be deformed between the unfolded state and the folded state. In the baby stroller, when the body is viewed from the left and right directions, the handlebar can be divided into two parts, an upper rod part (30b) and a lower rod part (30c), with the middle curved part (30a) as the boundary. The lower rod part (30c) is offset rearward relative to the extension line (EL) of the upper rod part. The front linkage part and the rear linkage part are connected to the lower rod part and can rotate. When the baby stroller in the unfolded state is viewed from the left and right directions of the body, the upper rod part, the middle linkage part and the front legs are arranged in a straight line.

In the present invention, the handlebar can be divided into an upper and lower portion. The lower portion is curved relative to the upper portion so that it is offset toward the rear of the stroller body relative to the extension of the upper portion. Therefore, even though the lower portion of the handlebar is connected to the front and rear legs via front and rear linkage components, allowing the handlebar, front and rear legs to interlock between the deployed and folded positions, the connection between the lower portion and the front and rear linkage components can be retracted into an area closer to the rear of the stroller body than the extension of the upper portion. Furthermore, the upper portion can be tilted so that its extension aligns with the intermediate linkage component and the front legs, transmitting operating force from the upper portion to the front legs in a straight line via the intermediate linkage component. Consequently, the force pushing the stroller body acts near or in front of the front wheel's rotation axis, pulling the front wheel from the front and causing it to rotate about the rotation axis. Consequently, wobbling of the front wheel about the rotation axis is suppressed, maintaining a stable orientation for both straight-ahead travel and rotation. This improves the stroller's operability.

In one technical solution of the present invention, the upper rod portion can be arranged in such a manner that an extension line of the upper rod portion intersects with an imaginary horizontal plane (HP) containing the axis of the axle (21) of the front wheel on or in front of the axle of the front wheel. According to such an arrangement, the force for pushing the stroller can be reliably applied to the axle of the front wheel or the area in front of the axle, thereby further improving the stability of the front wheel.

The connection point (34) between the intermediate linkage component and the handle bar can be arranged on one side of the lower rod. Thus, since the lower rod is located behind the extension line of the upper rod, the connection point between the intermediate linkage component and the handle bar is close to the extension line of the upper rod, which can further improve the linearity of the upper rod, the intermediate linkage component and the front leg.

In one technical solution of the present invention, an opening and closing locking mechanism may be further provided between at least one of the front and rear linkage components (36) and the handlebar, the opening and closing locking mechanism being used to switch the handlebar and the linkage component between a state in which relative rotation is possible and a state in which relative rotation is not possible. Thus, the baby carriage can be locked in an unfolded state or a folded state by utilizing the opening and closing locking mechanism.

In the above technical solution, a lower pin (37) connecting the handle bar and the rear linkage component and enabling the two to rotate relative to each other can be provided at the connection point between the handle bar and the rear linkage component, and a locking component (50) and a lock receiving portion (56) are provided on the opening and closing locking mechanism, wherein the locking component can move between a release position and a lock position along the handle bar, and the lock receiving portion can rotate together with the rear linkage component around the lower pin. When the locking component moves to the lock position, the locking component and the lock receiving portion are engaged and cannot rotate relative to each other around the lower pin, thereby preventing the handle bar and the rear linkage component from rotating relative to each other. When the locking component moves to the release position, the engagement between the locking component and the lock receiving portion is released, thereby enabling the handle bar and the rear linkage component to rotate relative to each other. According to this technical solution, the locking component and the lock receiving portion can be engaged near the lower pin connecting the handle bar and the rear linkage component, thereby reducing the load acting on the locking component or the lock receiving portion, thereby achieving miniaturization and lightness of these components.

Furthermore, when the stroller is in the expanded state, the locking member and the lock receiving portion can engage and cannot rotate relative to each other about the lower pin. However, when the stroller is in the process of deformation between the expanded state and the folded state, the locking member and the lock receiving portion cannot engage. Furthermore, when the stroller is in the folded state, the locking member and the lock receiving portion can engage and cannot rotate relative to each other about the lower pin. This allows the opening and closing locking mechanism to reliably operate, locking the stroller in the expanded state. Furthermore, the opening and closing locking mechanism will not malfunction during the stroller's deformation process. Furthermore, the stroller can also be locked in the folded state.

In the above technical solution, the lower pin and the rear linkage component can both be made of metal, and the lower pin is respectively engaged with the handle bar and the rear linkage component. Thus, a load transfer path from the handle bar through the lower pin to the rear linkage component is formed by the metal component. Therefore, it is possible to suppress the load on other components of the opening and closing locking mechanism, such as the locking component or the lock receiving portion, by forming these components using non-metallic materials such as resin. In addition, the rear linkage component and the rear leg can be connected and rotatable by a metal rear connecting pin. Thus, the load transfer path from the handle bar through the rear linkage rod to the rear leg can be formed by the metal component, thereby maintaining the strength and rigidity of the vehicle body at a high level.

In one technical solution of the present invention, a lower bracket (40) can be provided on the rear legs, and when the baby carriage is in the unfolded state, the lower bracket blocks the lower end of the handle bar from below. Thus, at least a portion of the downward load acting on the handle bar is directly supported by the rear legs, thereby reducing the burden on the components arranged at the connection portion between the handle bar and the front linkage component and the rear linkage component.

Furthermore, a pair of engaging portions (59, 40b) may be provided between the lower end of the handlebar and the lower bracket, and when the stroller is in the unfolded state, the pair of engaging portions engage with each other in the left-right direction of the stroller body. Thus, even if the handlebar and the rear legs are connected by a plurality of parts, the gap between the handlebar and the rear legs in the left-right direction does not increase, and the shaking of the stroller body in the unfolded state can be suppressed.

In one technical solution of the present invention, a hand grip (43) can be provided on the upper end side of the handlebar, and the hand grip is curved in such a manner that it gradually shifts toward the front of the vehicle body from the outer side to the inner side in the left-right direction of the vehicle body. In this case, the user can easily put his hand on the hand grip, thereby improving the operability of the baby stroller.

In one technical solution of the present invention, a storage basket (5) can be suspended below the vehicle body by a connecting belt (120). On the connecting belt, a stopper (120b) is formed by overlapping the connecting belt itself and connecting it. A hook (121) is fixed on the storage basket. The hook has a cutout (121a) through which the connecting belt can pass. The stopper prevents the connecting belt from falling out of the hook after entering the hook through the cutout, thereby forming a loop. The structural components (38, 39) of the vehicle body enter the loop, and the connecting belt is locked on the vehicle body. According to such a technical solution, the connecting belt is overlapped to form a stopper, thereby reducing the number of parts required for installing the storage basket.

In the above description, reference numerals in parentheses are used to facilitate understanding of the present invention; however, the present invention is not limited to the drawings.

As described above, the present invention can be constructed in the following manner: by bending the lower handlebar portion relative to the upper handlebar portion so that it is offset toward the rear of the vehicle body relative to the extension line of the upper handlebar portion, the connection portion between the lower handlebar portion and the front and rear linkage components is retracted into an area closer to the rear of the vehicle body than the extension line of the upper handlebar portion. Furthermore, the upper handlebar portion can be tilted so that its extension line extends along the intermediate linkage component and the front legs, transmitting operating force from the upper handlebar portion to the front legs in a straight line via the intermediate linkage component. This suppresses the shaking of the front wheel centered about the rotation axis, maintaining a stable orientation of the front wheel both during straight-line travel and during rotation. This not only maintains the stroller's folding function but also improves its operability compared to current strollers.

The wheel device (12) of the hand truck (1) of the present invention comprises: a vehicle body (2); an axle (25) mounted on the vehicle body (2) via a wheel holding member (24); and a wheel (26) mounted on the axle so as to be rotatable about the axle. The wheel device comprises a plurality of protrusions (93) and a locking operating member (91). The plurality of protrusions are provided on a side of the wheel opposite to the wheel holding member and are arranged at predetermined intervals about the axle. The locking operating member is mounted on the wheel holding member so as to be swung about a swing axis (91) parallel to the axle between a locked position and a unlocked position. A stopper (92a) is provided at a position of the locking operating member away from the swing axis. When the locking operating member is in the locked position, the stopper fits into a gap between the plurality of protrusions and engages with the protrusions in the circumferential direction of the axle. When the locking operating member is in the unlocked position, the stopper retracts from the protrusion. The arc described by the center position (SC) of the stop portion when meshing with the protrusion with the axle as the center is set as the rotation trajectory (C1) of the protrusion, and the arc described by the center position of the stop portion with the swing axis as the center is set as the rotation trajectory (C2) of the stop portion. When tangents (α, β) relative to the respective rotation trajectories are drawn at the intersection (P) of the two rotation trajectories, the relationship between the stop portion and the protrusion is set as follows: the angle (θ) between the two tangents is approximately 90°.

According to the present invention, when a moment acts on the wheel while the stopper is embedded in the gap between the protrusions, regardless of the direction of the moment, a thrust acts between the protrusion and the stopper in a direction tangential to the rotational trajectory of the protrusion. The force component in the direction of pushing the stopper out of the gap between the protrusions does not act, or if it does, it is extremely small. Therefore, the vehicle's rotation can be stably restricted regardless of the direction of wheel rotation.

In one technical solution of the present invention, each of the protrusions may be provided with a base portion (93a) and an enlarged portion (93b), wherein the base portion extends in the radial direction of the vehicle and the enlarged portion is arranged on the outer periphery of the base portion. Thus, the enlarged portion of the protrusion can suppress the stopper from falling off.

Also, the outer peripheral side of the enlarged portion may be tapered toward the top, so that when the locking operating member is operated in the locked position, the stopper easily enters the gap between the protrusions.

In one embodiment of the present invention, the wheel can be mounted on the axle by causing the end face (82e) of the wheel facing the wheel holding member to contact the limiting face (81a) of the wheel holding member in the direction of the axle in the upper region of the axle. In this case, the end face of each protrusion in the direction of the axle can contact the limiting face of the wheel holding member as the end face facing the wheel holding member. By mounting the wheel in this manner, the limiting face can suppress the wheel from tilting toward the wheel holding member. In addition, a bearing member (84) that can rotate relative to the axle can be mounted on the axle, and the wheel is engaged with the bearing member and cannot rotate relative to the bearing member. Therefore, sliding can also occur between the bearing member and the axle, and wear between the wheel and the bearing member will not occur, or even if wear occurs, the wear rate is extremely slow. When a significant gap is formed between the axle and the bearing member due to wear or deformation of the bearing member, simply replacing the bearing member can prevent the wheel from shaking relative to the axle and prevent the shaking from increasing.

The above technical solution is particularly suitable for situations where only one wheel is mounted on the axle. Specifically, when only one wheel is mounted on an axle, the wheel load is greater than when multiple wheels are mounted on the same axle, which can easily cause wheel sway or wobble. However, the above technical solution can resolve or prevent these problems. Furthermore, the single wheel can be mounted on the axle on the outside of the vehicle body in the left-right direction relative to the wheel retaining member. This can prevent the wheel, which is positioned on the outside of the vehicle body in the left-right direction, from tipping inward due to wobble relative to the axle.

In one technical solution of the present invention, the wheel device may further include an axle cover (100) that can be installed on and removed from the wheel. In this case, a claw (103) for locking the wheel may be provided on the axle cover, the claw being hidden on the back side of the axle cover so that the user cannot see it, and the claw being excluded from the scope of the surface treatment performed on the surface side of the axle cover. This can prevent poor engagement, embrittlement, or increased risk of breakage due to reduced elasticity caused by changes in the size of the claw due to surface treatment. When surface treatment is performed by immersing the plating solution or the like in the treatment solution, it is not necessary to immerse the claw in the treatment solution. Therefore, there is no need to mask the claw, which can reduce working hours.

In the above description, reference numerals in parentheses are used to facilitate understanding of the present invention; however, the present invention is not limited to the drawings.

As described above, in the present invention, the stopper and protrusion are positioned in a specific relationship so that the thrust acts tangentially to the rotational trajectory of the protrusion between the protrusion and the stopper. Consequently, the force component that pushes the stopper out of the gap between the protrusions is either negligible or extremely small. Consequently, the vehicle's rotation can be stably restricted regardless of the wheel's rotational direction.

The baby carriage of the present invention comprises a body (2) and a seat (3) mounted on the body.

The seat is formed as a subassembly by attaching a seat material (61) to a seat frame (62) and a back frame (63) while applying tension to these components. The seat frame has a structure in which a pair of left and right side tubes (62a) are connected by a front tube (62b), and the back frame has a structure in which a pair of left and right side tubes (64) are connected by a head tube (65). The seat is mounted on the vehicle body by connecting the side tubes of the seat frame and the back frame of the seat formed as a subassembly to the vehicle body.

In the stroller of the present invention, because the left and right side tubes of the seat frame are connected by a front tube, and the left and right side tubes of the back frame are connected by a head tube, both the seat frame and the back frame can be given sufficient rigidity as a single component. Consequently, by stretching the seat material while connecting it to the seat and back frames, the "tensile force" of this seat component can be utilized to form the seat as a rigid subassembly capable of supporting an infant. Furthermore, by connecting the side tubes of the seat and back frames to the vehicle body, the seat can be mounted on the vehicle body. This can eliminate the need for core material, reduce the number of components, or improve seat assembly efficiency.

In one technical solution of the present invention, a seat support component (70) extending in the left-right direction of the vehicle body can be provided on the back side of the seat on the vehicle body, and the seat material and the seat support component are connected by a connecting belt (71) at a position near the intersection of the seat frame and the back frame. Thus, the seat material can be clearly divided into areas corresponding to the seat and the back, respectively, with the installation position of the connecting belt as the boundary.

In addition, the seat material can be formed of a mesh, which not only allows the seat material to be stretched but also allows the seat to have higher air permeability.

In addition, the side tubes of the back frame are mounted on the vehicle body via a retaining member (53) that is rotatable about an axis in the left-right direction of the vehicle body, and a mechanism (73) for adjusting the inclination of the back frame relative to the vehicle body can be provided between the seat and the vehicle body, thereby enabling adjustment of the inclination of the back frame.

Furthermore, handle bars (30) for transmitting a user's operating force to the vehicle body can be provided on both sides of the vehicle body in the left and right directions, and the side tubes of the seat frame and the back frame can be connected to the handle bars. Generally speaking, since the area near the boundary between the seat and the back of the chair is located inside the lower end of the handle bar, the handle bar can be used as the object of the side tubes of the seat frame and the back frame, which is conducive to miniaturization and simplification of the connection structure between the side tubes and the vehicle body.

Furthermore, a sunshade (4) can be provided between the left and right handle bars, and the sunshade can be switched between an unfolded state in which the sunshade is opened to cover the seat from above and a folded state in which the sunshade is folded to the rear of the vehicle body. The sunshade comprises: a mounting portion (113a) mounted on the left and right handle bars respectively; and a rotating portion (113c) rotatable relative to the mounting portion around an axis in the left-right direction of the vehicle body. The sunshade comprises a sunshade base (113), a sunshade support rod (114), a sunshade awning (115), and a plurality of sunshade ribs (116) between the mounting portion and the rotating portion, wherein a position holding mechanism is provided on the sunshade base, and the position holding mechanism selectively holds the rotating portion at one of a plurality of stop positions within a rotation range; the sunshade support rod is mounted on the rotating portion in an arc-shaped manner between the rotating portion of the sunshade base; the sunshade awning is made of an elastic sunshade material, and is connected to the sunshade by winding the sunshade support rod into the inner side of its front end portion. The sunshade support rod is connected. When the sunshade is in the deployed state, the plurality of sunshade ribs are spaced apart in the fore-aft direction of the vehicle body, and their ends are fixed to the awning with both ends converged near the rotating portion of the sunshade base. Rotating the rotating portion of the sunshade base causes the sunshade support rods to rotate forward, thereby switching the sunshade to the deployed state. In this deployed state, the sunshade support rods are held in a position corresponding to the deployed state by the position retaining mechanism of the sunshade base, and the awning is subjected to tension, maintaining its shape. Thus, the sunshade is maintained in the deployed state by the tension of the single sunshade support rod and the awning. The sunshade ribs only need to be fixed to the awning so that the awning extends into an arc shape. If the sunshade ribs are to be mounted at a predetermined position in the fore-aft direction of the vehicle body, they do not need to be attached to the awning base. In order to maintain the interval between the sunshade support rod and the sunshade rib, or between the sunshade ribs, it is not necessary to set components such as operating handles or springs, or even if they are required, only a few components are installed, thereby reducing the number of components.

Furthermore, a winding portion (117) can be provided on both sides of the awning, and the winding portion is connected to the handle bar in a manner of being wound around the handle bar. Thus, by connecting the handle bar and the awning, tension can be generated between the winding portion and the sunshade support rod, thereby improving the shape retention effect of the sunshade. In addition, the winding portion can be provided in a manner corresponding to a position of the plurality of sunshade ribs. Thus, since the sunshade rib can be maintained along the handle bar, the shape retention effect of the sunshade can be improved.

In addition, buckle parts (115a) can be provided on both sides of the sunshade and at the portion where the ends of the plurality of sunshade ribs are concentrated, and the buckle parts can be locked to the outer periphery of the mounting part or the rotating part of the sunshade. Therefore, by locking the buckle parts, the ends of the sunshade ribs can be roughly maintained around the mounting part, that is, around the rotation center of the sunshade support rod.

In the above description, reference numerals in parentheses are used to facilitate understanding of the present invention; however, the present invention is not limited to the drawings.

As described above, in the present invention, the seat material is stretched and attached to the seat frame and back frame, forming the seat as a rigid subassembly capable of supporting an infant or child. Furthermore, the seat is attached to the vehicle body by connecting the side tubes of the seat frame and back frame to the vehicle body. This eliminates the need for core material, reduces the number of components, and significantly improves seat assembly efficiency. Furthermore, even when a sunshade is provided, the sunshade can be maintained in its extended position by utilizing the tension of a single sunshade support rod and the sunshade canopy, thereby reducing the number of components required for additional sunshades.

The baby carriage (1) of the present invention comprises: a body (2) including front legs (14) and rear legs (15); a handlebar (30) provided on the side of the body to transmit a user's operating force to the body, wherein the lower end of the handlebar is connected to the rear legs, and the cross-sectional shapes of the front legs and the rear legs have a direction in which the cross-sectional dimensions are larger and a direction in which the cross-sectional dimensions are smaller. In the baby carriage, the front legs are arranged such that the direction in which the cross-sectional dimensions are larger corresponds to the left-right direction of the body, and the rear legs are arranged such that the direction in which the cross-sectional dimensions are smaller corresponds to the left-right direction of the body.

In the stroller of the present invention, since the lower end of the handlebar, located at the rear of the stroller, is connected to the rear legs, the rear legs are located below the handlebar. The downward load transmitted by the handlebar is applied more heavily to the rear legs than to the front legs, subjecting them to a greater bending moment along the vertical plane. Therefore, by arranging the rear legs with their smaller cross-sectional dimensions oriented in the left-right direction of the stroller, the section modulus and secondary moment of area relative to the load direction are maintained, thereby improving bending strength and rigidity. As for the front legs, since the load applied to them is relatively small, they are arranged with their larger cross-sectional dimensions oriented in the left-right direction of the stroller. This ensures a larger projected area for the front legs when the stroller is viewed from the front. Consequently, the front legs easily draw the user's attention when the stroller is viewed from the front, enhancing their visual impact. This ensures both bending strength and rigidity, while also providing a visually appealing experience for the user. In addition, by giving the front legs distinctive colors and patterns that are different from other parts, or by using the front surfaces of the front legs as display surfaces for trademarks or product names, the user's attention can be attracted, and the design or trademark of the stroller can leave a deep impression on the user.

In one embodiment of the present invention, the handlebar and the rear leg may be arranged so that the rear leg blocks the lower end of the handlebar from below. In this case, the downward load acting on the handlebar is applied more strongly to the rear leg, thereby more effectively exerting the effects of the present invention.

Furthermore, in the cross section of the front leg, the front surface of the front leg can be designed to be an arched arc facing the front of the vehicle body, thereby giving the front leg a more prominent feature in design.

The baby carriage of the present invention can also have an intermediate linkage component (16), a front linkage component (35), and a rear linkage component (36), wherein one end of the intermediate linkage component (16) is connected to the upper end of each of the front legs and the rear legs and can rotate, and the other end is connected to the handle bar and can rotate; one end of the front linkage component (35) is connected to the handle bar at a position (37) lower than the connection point (34) between the connecting rod and the intermediate linkage component and can rotate, and the other end is connected to the handle bar at a position (38) lower than the connection point (29) between the front legs and the intermediate linkage component. The front leg is connected to the rear linkage member and is rotatable; one end of the rear linkage member (36) is connected to the handlebar at a position (37) lower than the connection point between the connecting rod and the intermediate linkage member and is rotatable, and the other end is connected to the rear leg at a position (39) lower than the connection point (29) between the rear leg and the intermediate linkage member and is rotatable; by making the front leg, the rear leg, the handlebar, the intermediate linkage member, the front linkage member and the rear linkage member rotate relative to each other around each connection point, the baby carriage can be deformed between the unfolded state and the folded state. In such a foldable baby carriage, the downward load applied by the handlebar may be applied to the rear leg from the lower end of the handlebar to a large extent. Therefore, by setting the orientation of the front and rear legs according to the present invention, it is possible to simultaneously ensure bending strength and rigidity as well as the visual effect provided to the user.

In the above description, reference numerals in parentheses are used to facilitate understanding of the present invention; however, the present invention is not limited to the drawings.

As described above, in the present invention, the front legs are arranged in such a manner that the direction of the larger cross-sectional dimension corresponds to the left-right direction of the vehicle body, and the rear legs are arranged in such a manner that the direction of the smaller cross-sectional dimension corresponds to the left-right direction of the vehicle body. Therefore, the rear legs ensure the bending strength and rigidity to withstand downward loads, and the front legs improve the visual effect when viewing the stroller from the front, thereby ensuring the bending strength and rigidity as well as the visual effect provided to the user at the same time.

The baby carriage (1, 1A) of the present invention has a body (2) and armrests (16) with a frame structure, wherein the body (2) can be deformed between an unfolded state and a folded state, and the armrests (16) are respectively arranged on both sides of the body in the left and right directions, and the upper ends of the front legs (14) and the rear legs (15) of the body are connected to the front end (16a) of the armrest and can rotate. In the folded state, the armrest is inclined downward from the front end to the rear end (16b) along the rear legs, and the armrest has: a top plate (16c) facing upward; side plates (16d, 16e) extending along the two side edges of the top plate toward the left and right directions of the body, and the area surrounded by the top plate and the side plates is a cavity, which is formed into a shape opening toward the lower surface side. In the baby stroller, the distance from the center line (CL1) of the rear legs in the left-right direction of the vehicle body to the side panels (16d) located on the left-right outer sides is greater than the distance from the center line of the rear legs to the side panels (16e) located on the left-right inner sides.

According to the present invention, when the stroller is folded, the armrests tilt diagonally downward from the front to the rear, with their lower surfaces approaching the rear legs, which are tilted in the same direction. Near the connection between the armrests and the rear legs, a portion of the rear legs retract into the armrests. In this manner, the outer side panels are positioned farther from the centerline of the rear legs than the inner side panels in the left-right direction of the stroller, leaving ample clearance between the outer side panels and the rear legs. This effectively prevents the user's fingers from being pinched between the outer side panels of the armrests and the rear legs.

In one embodiment of the present invention, a gap (S2) greater than or equal to a required gap is maintained between the rear leg and the left-right outer side panel of the armrest. The gap is defined as the minimum gap required to prevent the user's fingers from being pinched. This ensures that fingers are prevented from being pinched between the armrest and the rear leg.

Furthermore, in the folded state, a gap (S3) greater than the required gap can be ensured between the rear legs and the top plate, and a recess (16f) can be provided on the side plate on the inner side in the left-right direction so that the gap between the rear legs and the top plate can be opened to the outside of the armrest. This can improve the effect of preventing fingers from being pinched inside the armrest without causing the armrest to bulge excessively inward in the left-right direction of the vehicle body.

In addition, in the folded state, the connection position between the front legs and the armrests can be biased forward of the connection position between the rear legs and the armrests, thereby improving the effect of preventing fingers from being pinched between the front legs and the rear legs.

In addition, a handlebar (30) for transmitting a user's operating force to the vehicle body can be provided on the vehicle body, the rear end of the armrest is connected to the handlebar and is rotatable, and in the folded state, a gap (S4) greater than the required gap is ensured between the rear end of the armrest and the handlebar, thereby preventing fingers from being pinched between the handlebar and the armrest.

In the above description, reference numerals in parentheses are used to facilitate understanding of the present invention; however, the present invention is not limited to the drawings.

As described above, according to the present invention, in the left-right direction of the vehicle body, the outer side panels of the armrest are farther away from the center line of the rear legs than the inner side panels of the armrest, thereby ensuring a sufficient gap between the outer side panels and the rear legs. Therefore, when the vehicle body is folded, the armrest is inclined obliquely downward from the front end to the rear end, and its lower surface side is close to the rear legs inclined in the same direction, or, near the connection part between the armrest and the rear legs, a part of the rear legs enters the interior of the armrest. Even in this case, the effect of preventing the user's fingers from being pinched between the outer side panels of the armrest and the rear legs can be improved.

The baby carriage (1) of the present invention comprises a body (2) and a seat (3), wherein the body is deformable between an unfolded state and a folded state, the seat comprises a seat portion (3a) and a back portion (3b), the back portion comprises a back support component (64) and a head component (65), wherein one end portion of the back support component is connected to the body via a back connection point (37, D) and is rotatable, the head component is connected to the other end portion of the back support component via a head connection point (66a, A) and is rotatable, the head component is connected to the body via a linkage component (67), one end portion of the linkage component is connected to the body via a linkage component (67) and one end portion of the linkage component is connected to the body via a linkage component (67) and is moved upward away from the back connection point The front connection point (68, C) is connected to the vehicle body and can rotate, and the other end of the linkage component is connected to the head component through a candidate connection point (69, B) away from the head connection point and can rotate, so that the vehicle body, the back support component, the head component and the linkage component constitute a four-bar mechanism. In the folded state, the back support component and the linkage component are rotated around the back connection point and the front connection point, so that the back can move between an extended position (the position shown in Figure 39) in which it is tilted toward the rear of the vehicle body and a stowed position (the position Ps shown in Figure 42) in which it is erected toward the front of the vehicle body. In this stroller, when the back is located in an area on the side of the storage position compared to the limiting position (position Px shown in Figure 42) between the extended position and the storage position, the rotational movement centered on one connection point (66a, A) among the head connection point or the rear connection point is restricted, and a connection structure (66) centered on the one connection point is formed. When the back is moved beyond the limiting position to the area on the side of the storage position, the back is elastically deformed, and under the action of the restoring force relative to the elastic deformation, the storage position (Ps) is set to a position that produces the effect of keeping the back in the storage position.

According to the stroller of the present invention, when the back portion reaches the restricted position, rotational movement about a connection point that is not located on the body side, i.e., a connection point on the head portion side, is restricted. If the structural components of the back portion were completely rigid, rotational movement about all the connection points would need to be allowed for the four-bar linkage to operate. If rotational movement about a single connection point is restricted, the four-bar linkage cannot operate. Therefore, the back support component and linkage components of the back portion cannot be rotated from the restricted position toward the stowed position. However, in practice, by causing the structural components of the back portion to elastically deform, the back portion can be moved beyond the restricted position toward the stowed position. The amount of elastic deformation of the back portion increases or decreases depending on the relationship between the rotational movement of the back support component about the back connection point and the rotational movement of the linkage component about the connection point. The amount of elastic deformation of the back portion changes as follows: the elastic deformation increases immediately after the back portion passes the restricted position, decreases during movement, and then increases again. After the elastic deformation decreases, if the backrest attempts to return to the extended position, the elastic deformation increases, and a restoring force begins to act to prevent the backrest from moving back to the extended position. This property allows the restoring force against the elastic deformation of the backrest to maintain the backrest in the stowed position. This effect is achieved by moving the backrest beyond the restraining position toward the stowed position. Therefore, without relying on restraining components, the backrest can be maintained in the stowed position simply by moving the backrest toward the stowed position.

In one embodiment of the present invention, the stowed position can be set by moving the back until an intersection (P2) coincides with another connection point (point B), thereby causing the back to reach the stowed position. When the back is at the restricted position, the intersection of the rotation trajectory (Et, Bt) drawn by rotating the other connection point (69, B) of the head connection point or the rear connection point about the back connection point and the front connection point is the intersection (P2), and the intersection (P2) is closer to the front of the vehicle body than the other connection point at the restricted position. In this embodiment, when the back reaches the stowed position, the other connection point reaches the intersection of the two rotation trajectories, and the back is released from the elastically deformed state. Since the amount of elastic deformation increases regardless of the direction in which the back is moved from this position, the back can be reliably maintained at the stowed position where elastic deformation and restoring force relative to the elastic deformation are not generated.

In one embodiment of the present invention, the inclination of the backrest can be changed in the deployed state. A connection structure centered on the single connection point can be configured such that when the backrest exceeds its range of movement in the deployed state and rises toward the front of the vehicle body, the connection structure causes the backrest to reach a restricted position. Thus, in the deployed state, the four-bar mechanism of the backrest can rotate without hindering this movement, thereby changing the inclination of the backrest.

In one embodiment of the present invention, a side member (64) extending along the left and right side edges of the back portion is provided as the back support member, the head member is provided in a manner connecting the left and right side members, and the linkage member is provided in a manner connecting the head member and the body on the left and right sides of the back portion, thereby forming the four-bar mechanism on each side edge of the back portion. This can limit the rotational movement of the four-bar mechanism on both sides of the back portion at the limit position, thereby producing an effect of keeping the back portion in the stowed position on both sides of the back portion.

In one embodiment of the present invention, a gap (S8, S9, S15, S16) greater than or equal to a required gap is maintained around each connection point during movement of the back portion from the extended position to the stowed position. The required gap is defined as the minimum gap required to prevent fingers from being pinched. This prevents fingers from being pinched near each connection point when the back portion is stowed.

In the above description, reference numerals in parentheses are used to facilitate understanding of the present invention; however, the present invention is not limited to the drawings.

As described above, according to the present invention, during the process of the back of the seat moving from the restricted position to the stowed position, the rotation movement centered on a connection point on the head component side is restricted, causing the back to undergo elastic deformation, and the restoring force generated by the elastic deformation is utilized to maintain the back in the stowed position. Thus, without the back of the seat relying on the restricting component, the back of the seat can be maintained in the stowed position by the simple operation of moving the back of the seat to the stowed position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a perspective view of a baby carriage according to an embodiment of the present invention.

FIG. 2 is a right side view of the baby carriage shown in FIG. 1 .

FIG. 3 is a perspective view showing the body structure of the baby carriage shown in FIG. 1 .

FIG. 4 is a right side view of the vehicle body structure shown in FIG. 3 .

FIG. 5 is a diagram showing the stroller shown in FIG. 1 in a folded state.

FIG6 is a perspective view showing the state when the upper portion of the push frame is viewed from obliquely behind the vehicle body.

FIG. 7 is a top view obtained with the handle as the center.

FIG8 is a perspective view showing a state where the lower portion of the vehicle body is viewed from an oblique rear side.

FIG9 is a diagram showing the relationship between the cross-sectional shapes of the front legs and rear legs and the direction of the vehicle body.

FIG. 10 is an enlarged view showing a state where a connection portion of structural members of a vehicle body is viewed from the side of the vehicle body.

FIG11 is a perspective view showing the connection member shown in FIG10 when viewed obliquely from the rear of the vehicle body.

FIG. 12 is a side view showing a state in which the back frame of the seat is erected.

FIG13 is a perspective view of a state where the back frame of the seat is erected, as viewed from the oblique rear of the vehicle body.

FIG. 14 is a cross-sectional view taken along the lower pin of the opening and closing locking mechanism.

FIG. 15 is a perspective view showing the state of the open/close lock mechanism as viewed obliquely from the rear of the vehicle body.

FIG. 16 is a perspective view showing a state where the locking member and the lock receiving portion of the open/close locking mechanism are viewed from the inner side of the vehicle body.

FIG. 17 is a diagram showing a state when the seat portion of the seat is viewed from the front side.

FIG. 18 is a diagram showing a state in which the seat is viewed obliquely from the rear of the vehicle body.

FIG19 is a diagram showing a state where the rear wheel and its surrounding structure are viewed from obliquely behind the vehicle body.

FIG. 20 is a diagram showing a state where the rear wheel and its surrounding structure are viewed from the direction of arrow XX in FIG. 19 .

FIG. 21 is a diagram showing a rear wheel support mechanism along the axle.

FIG. 22 is a diagram showing main components of the rear wheel locking mechanism.

FIG. 23 is a diagram showing the relationship between the stopper pin of the rear wheel locking mechanism and the protrusion on the rear wheel side.

FIG24 is a perspective view of the front surface side of the shaft cover.

FIG25 is a perspective view of the rear side of the shaft cover.

FIG26 is a perspective view of the pedal portion and its surrounding structures.

FIG27 is a diagram showing the structure of the back side of the step portion.

FIG28 is an enlarged view of the sun shield and its surroundings.

FIG29 is an enlarged view of the mounting portion of the sunshade relative to the push frame.

FIG30 is a diagram showing a connection belt for hanging the storage basket on the vehicle body

FIG. 31 is a diagram showing a state in which the connection belt is mounted on the front connection pin.

FIG. 32 is an enlarged view showing the armrest and its surrounding structure in the folded state as viewed from the outside in the left-right direction of the stroller.

FIG33 is a front view obtained when looking at the periphery of the armrest from the direction of arrow XXXIII in FIG32.

FIG34 is a cross-sectional view taken along line XXXIV-XXXIV of FIG32 .

FIG. 35 is a diagram showing the armrest and its surrounding structure in the folded state as viewed from the back side of FIG. 32 .

FIG36 is a perspective view showing the portion shown in FIG35 as seen from the oblique front of the stroller.

FIG37 is a diagram showing a state where the periphery of the lower pin is viewed from the direction of arrow XXXVII in FIG5 .

FIG. 38 is a perspective view showing the surroundings of the lower pin as viewed from the inside of the stroller.

FIG. 39 is a diagram showing a state in which the back portion frame is projected rearward in the folded state.

FIG. 40 is a diagram showing a state in which the back portion frame is being stored on the handlebar side in the folded state.

FIG. 41 is a diagram showing a state in which the back portion frame is stored on the handlebar side in the folded state.

FIG42 is a schematic diagram showing the movement of the back portion frame in the folded state.

FIG. 43 is a diagram corresponding to FIG. 4 , showing a baby carriage according to a modified example.

DETAILED DESCRIPTION

Next, a baby stroller according to an embodiment of the present invention will be described. First, the overall structure of the baby stroller will be described with reference to Figures 1 to 5. The baby stroller 1 includes: a body 2; a seat 3 supported by the body 2; a sunshade 4 disposed above the seat 3; and a storage basket 5 disposed below the seat 3. In Figures 3 to 5, part or all of the sunshade 4 is omitted from the illustration, and only the frame portion of the seat 3 is shown. In Figures 4 and 5, the illustration of the storage basket 5 is also omitted. The baby stroller 1 is capable of transforming between an unfolded state (unfolded state) as shown in Figures 1 to 5 and a folded state (folded state) as shown in Figure 5. Next, the structure of the baby stroller 1 will be described with the unfolded state as the center.

As clearly shown in Figures 3 and 4 , the vehicle body 2 includes a frame portion 10, a front wheel portion 11, and a rear wheel portion 12, which support the movement of the frame portion 10. The frame portion 10 constitutes the framework structure of the vehicle body 2 and includes a pair of front legs 14, which are arranged on either side of the stroller 1 (vehicle body 2) in the left-right direction (lateral direction); a pair of rear legs 15; a pair of armrests (intermediate linkage members) 16; a hand push frame 17, which is arranged so as to connect the left and right armrests 16; a footrest portion 18, which serves as a front cross member, which connects the lower portions of the left and right front legs 14; and a rear cross member 19, which connects the lower portions of the left and right rear legs 15.

The front wheel unit 11 is mounted on the lower end of the front leg 14, and the rear wheel unit 12 is mounted on the lower end of the rear leg 15. Each front wheel unit 11 includes a front wheel holding member 20 mounted on the lower end of the front leg 14; a horizontal axle 21 supported by the front wheel holding member 20; and a pair of front wheels 22 arranged to sandwich the front wheel holding member 20 and rotatably mounted on the opposite ends of the axle 21. The front wheel holding member 20 includes a fixed portion 20a fixed to the front leg 14; and a rotating portion 20b rotatable relative to the fixed portion 20a about a rotation axis VA (see Figure 4) in the vertical direction. The axle 21 is mounted on the rotating portion 20b. Thus, the front wheel 22 and its axle 21 are rotatable about the rotation axis VA. The axle 21 is offset relative to the rotation axis VA. When the stroller 1 is moved forward, the axle 21 is held behind the front wheel retaining member 20 by the torque applied to the front wheel 22, centered around the rotation axis VA. The position of the front wheel 22 in this state is defined as the forward position of the front wheel 22. The front wheel retaining member 20 is provided with a rotation lock mechanism (not shown). This rotation lock mechanism, when operated by a lock handle 23 (see FIG8 ), locks the rotating portion 20b in a rotationally fixed position when the front wheel 22 is in the forward position. The rotation lock mechanism can utilize a well-known component, similar to that used in strollers, and a detailed description thereof is omitted here. Furthermore, the rear wheel portion 12 includes a rear wheel retaining member 24 attached to the lower end of the rear leg 15; an axle 25 supported by the rear wheel retaining member 24, oriented in the left-right direction of the vehicle body 2; and a single rear wheel 26 rotatably supported by the axle 25. The rear wheel 26 cannot rotate about its vertical axis. In other words, the axle 25 of the rear wheel 26 is normally oriented in the left-right direction of the vehicle body 2. In addition, the rear wheel 25 and its surrounding structure will be described in detail later.

On one side in the left-right direction of the vehicle body 2, the upper ends of each of the front legs 14 and the rear legs 15 are connected to the leg mounting portion 16a at the lower end of the armrest 16 by a fulcrum pin 29 and are rotatable. The structure of the other side in the left-right direction of the vehicle body 2 is the same as described above. The connection position (rivet 28) between the front leg 14 and the leg mounting portion 16a is slightly offset in the front-to-back direction of the vehicle body 2 relative to the fulcrum pin 29. In addition, the armrest 16 is a resin molded product, and in order for infants and young children to place their hands or arms on the armrest 16, the armrest 16 has a top plate 16c facing upward. The armrest 16 has a unique shape to prevent fingers from being pinched when folded, which will be described in detail later.

The push frame 17 includes a pair of left and right handlebars 30 and a grip bar 31 extending from the upper portions of these handlebars 30. Each handlebar 30 is divided into an upper bar 30b and a lower bar 30c, separated by a curved portion 30a in the middle of the handlebar 30. However, the upper and lower bars 30b, 30c, are formed integrally by bending a single metal pipe. As shown in Figure 4 , the lower bar 30c is bent toward the rear of the vehicle body 2 relative to an extension line EL of the upper bar 30b. An upper bracket 32 is fixedly attached to the lower bar 30c via rivets 33. The handlebar connection portion 16b at the upper end of the armrest 16 is attached to the upper bracket 32 via an upper pin 34. This allows the armrest 16 and the handlebar 30 of the push frame 17 to pivot relative to each other, with the upper pin 34 serving as a fulcrum. In addition, the rear ends of the front linkage rod (front linkage component) 35 and the rear linkage rod (rear linkage component) 36 are rotatably connected to the lower end of the lower rod portion 30c via a lower pin 37. The structures of these connecting parts will be described in detail later. The front end of the front linkage rod 35 is rotatably connected to the front leg 14 via a front connecting pin 38. The rear end of the rear linkage rod 36 is rotatably connected to the rear leg 15 via a rear connecting pin 39. The linkage rods 35, 36, and the connecting pins 38, 39 are all made of metal. Furthermore, a lower bracket 40 is fixed to the rear leg 15. When the stroller 1 is in the unfolded state, the lower end of the handlebar 30 abuts the lower bracket 40, thereby being blocked in the vertical direction by the rear leg 15. An opening and closing locking mechanism 41 is provided around the lower pin 37 for locking the stroller 1 in the unfolded and folded states. The opening and closing locking mechanism 41 will be described in detail later. Additionally, the lower bracket 40 may be formed integrally with the rear leg 15 .

The front legs 14, rear legs 15, armrests 16, handlebars 30, front linkage rods 35, and rear linkage rods 36 form connecting mechanisms on the left and right sides of the frame portion 10 of the vehicle body 2, respectively. The structures of the left and right connecting mechanisms are the same. By releasing the lock on the vehicle body 2 by the opening and closing locking mechanism 41, the structural components of the connecting mechanism rotate around their respective connection points, thereby enabling the baby carriage 1 to be deformed between the opened state shown in FIG1 and the folded state shown in FIG5. With reference to FIG4, the deformation from the unfolded state to the folded state is described as follows. When the baby carriage 1 is deformed from the unfolded state to the folded state, the front legs 14 are rotated counterclockwise relative to the armrests 16 around the fulcrum pin 29, the rear legs 15 are rotated clockwise relative to the armrests 16 around the fulcrum pin 29, and the armrests 16 are rotated clockwise relative to the lower rod portion 30c around the upper pin 34. As a result, the front and rear linkage rods 35, 36 rotate relative to the lower rod portion 30c around the lower pin 37. The front linkage rod 35 rotates relative to the front leg 14 around the front connecting pin 38, and the rear linkage rod 36 rotates relative to the rear leg 15 around the rear connecting pin 39. This causes the frame portion 10 of the vehicle body 2 to fold, as shown in Figure 5. In this folded position, the front wheels 22 and rear wheels 26 are slightly spaced apart in the front-to-back direction. At this point, the center of gravity of the stroller 1 lies between the front wheels 22, 26 in the front-to-back direction of the vehicle body 2. This allows the stroller 1 to stand upright in the folded position, supported by the front and rear wheels 22, 26. Because the rivet 28 connecting the front legs 14 is positioned slightly forward of the fulcrum pin 29, a gap is created between the front and rear legs 14, 15 when folded. This prevents the possibility of fingers being pinched, etc. This will be discussed in more detail later.

When viewing the unfolded stroller 1 from the left and right sides of the vehicle body 2, the upper rod portion 30b of the push frame 17 is aligned with the armrest 16 and the front leg 14. As one criterion for determining whether these are aligned, the upper rod portion 30b can be considered aligned if the extension line EL of the upper rod portion 30b extends through at least a portion of the armrest 16 and at least a portion of the front leg 14. Furthermore, when the front wheels 22 are in the forward position (the solid line position shown in FIG4 ), the upper rod portion 30b is preferably positioned so that its extension line EL intersects an imaginary horizontal plane HP containing the axis of the axle 21 at or in front of the axle 21. It is also preferred that the upper rod portion 30b be positioned so that its extension line EL intersects the imaginary horizontal plane HP at or in front of the rotation axis VA. Furthermore, since the upper bracket 32 is attached to the lower rod portion 30c, the upper pin 34 can be positioned close to the extension line EL.

The above-described relationship between the upper rod portion 30b, the armrest 16, the front legs 14, and the front wheels 22 provides the following advantages. When a force is applied to the front and rear wheels 22, 26, near their contact surfaces, the force exerted by the user pushing the vehicle body 2 via the handlebar 30 acts on an area near or in front of the rotation axis VA of the front wheel 22. Consequently, the front wheel 22 is pulled from the front, rotating about the rotation axis VA. This suppresses wobble of the front wheel 22 about the rotation axis VA, maintaining a stable orientation for both straight-ahead travel and rotational movement. This improves the maneuverability of the stroller 1. In contrast, conventional strollers in which the extension of the handlebar is positioned between the front and rear wheels or passes near the rear wheels tend to wobble about the rotation axis because the front wheel is pushed from behind. This compromises the stability of the orientation of the front wheel 22 and may worsen the user's maneuverability.

As shown in detail in Figures 6 and 7 , the handlebar 31 of the push frame 17 includes a connecting portion 42 connected to each of the left and right handlebars 30; a grip portion 43 bent so as to extend obliquely upward and forward of the vehicle body 2 relative to the connecting portions 42; and a connecting portion 44 located between the grip portions 43. The connecting portion 42 and the grip portion 43 are integrally formed by bending a metal pipe. The connecting portion 42 and the handlebar 30 are connected by a connector 45. Thus, even if the cross-sectional shapes of the handlebar 30 and the grip bar 31 differ, the handlebar 30 and the grip bar 31 can be securely connected by matching the shapes of the handle fitting portion 45a and the grip fitting portion 45b on one side of the connector 45 with the respective shapes of the handlebar 30 and the grip bar 31.

Each connector 45 has a built-in angle adjustment mechanism. This angle adjustment mechanism is designed to switch the grip engagement portion 45b of the connector 45 between a position in which it can rotate relative to the grip engagement portion 45a and a position in which it cannot rotate, thereby adjusting the tilt of the grip rod 31 relative to the handlebar 30. When the buttons 45c of the left and right connectors 45 are pressed simultaneously (see FIG6 ), the lock between the engagement portions 45a and 45b of the connectors 45 is released, allowing the tilt of the grip rod 31 relative to the handlebar 30 to change. When the buttons 45c are released, the engagement portions 45a and 45b of the connectors 45 cannot rotate relative to each other. The reference position of the grip rod 31 is defined as the position in which the connection portion 42 is approximately aligned with the upper portion 30b of the handlebar 30, in other words, the connection portion 42 is located on an extension line EL of the upper portion 30b. The grip portion 43 extends obliquely as described above. Thus, when the grip bar 31 is in the reference position, the grip portion 43 gradually shifts inward from the outside (the side connected to the handlebar 30) toward the front of the vehicle body 2. This makes it easier for the user to place their hand on the grip portion 43, improving the operability of the stroller 1. Furthermore, one-handed operation is also easy. When the grip bar 31 is tilted rearward relative to the reference position, the grip portion 43 gradually protrudes upward from the outside to the inside. Even in this case, it is easier for the user to place their hand on the grip portion 43, improving the operability of the stroller 1.

The connecting portion 44 is made of resin and is roughly hollow and cylindrical. The two ends of the connecting portion 44 are fitted into the grip portion 43, so that the connecting portion 44 and the grip portion 43 form a single unit. An opening and closing operating portion 47 for operating the opening and closing locking mechanism 41 of the vehicle body 2 is provided on the connecting portion 44. The opening and closing operating portion 47 includes: an operating handle 48, which is provided on the outer periphery of the connecting portion 44; and a connecting wire (not shown) which is linked to the operating handle 48 and is housed inside the grip rod 31. The connecting wire passes over the grip rod 31 and is pulled to near the lower end of the handle bar 30. The operating handle 48 is mounted on the connecting portion 44 in a state in which it can be slid in the left and right directions. When the operating handle 48 is located on the right side of the paper in Figure 6, the opening and closing operating mechanism 41 activates the locking function and locks the stroller 1 in the unfolded state or the folded state. When the operating handle 48 is operated to the left, the lock performed by the opening and closing locking mechanism 41 is released. As clearly shown in FIG5 , when the stroller 1 is folded with the handle bar 31 in the reference position, the grip portion 43 and the connecting portion 44 of the handle bar 31 are positioned approximately between the front wheel 22 and the rear wheel 26 in the front-to-rear direction of the vehicle body 2. This arrangement facilitates positioning the center of gravity of the stroller 1 between the front wheel 22 and the rear wheel 26 when in the folded state.

Figure 8 shows the front legs 14 and rear legs 15 as viewed from an oblique rear perspective, and Figure 9 illustrates the relationship between the cross-sectional shapes of the front legs 14 and rear legs 15 and the orientation of the vehicle body 2. The front legs 14 and rear legs 15 are formed by processing metal pipes, similar to the push frame 17 and handlebar 30. As clearly shown in Figure 9, the front legs 14 have a deformed hexagonal cross-section, while the rear legs 15 have a generally rectangular cross-section. In Figure 9, arrow F indicates the front of the vehicle body 2, arrow B indicates the rear of the vehicle body 2, arrow L indicates the left of the vehicle body 2, and arrow R indicates the right of the vehicle body 2. Although the front legs 14 and rear legs 15 have different cross-sectional shapes, their cross-sectional dimensions are both wider in the long direction and narrower in the short direction. Furthermore, the relationship between the orientation of the vehicle body 2 and the long and short directions of the cross-sectional dimensions differs for the front legs 14 and rear legs 15. The front legs 14 are arranged so that their long sides correspond to the left-right direction of the vehicle body 2 and their short sides correspond to the front-back direction of the vehicle body 2. In contrast, the rear legs 15 are arranged so that their long sides correspond to the front-back direction of the vehicle body 2 and their short sides correspond to the left-right direction of the vehicle body 2. The reason for this arrangement is as follows.

The rear legs 15 are located below the push frame 17. The push frame 17 is connected to the rear legs 15 via a rear linkage 36, and its lower ends are supported by lower brackets 40 on the rear legs 15. Therefore, when a user applies a downward load to the push frame 17, the load is applied more strongly to the rear legs 15 than to the front legs 14, generating a larger bending moment in the vertical plane. The rear legs 15 are positioned so that their longitudinal directions correspond to the longitudinal direction of the vehicle body 2. This ensures a greater section modulus and secondary moment of area relative to the load direction, thereby improving bending strength and rigidity. Furthermore, the front legs 14 are positioned so that their longitudinal directions correspond to the lateral direction of the vehicle body 2. This ensures a larger projected area for the front legs 14 when viewing the stroller 1 from the front. Consequently, the front legs 14 are more easily noticed when viewing the stroller 1 from the front, enhancing their visual appeal. This creates a sense of unity between the top plate 16c of the armrest 16 and the front legs 14, further enhancing their eye-catching effect. By giving the front legs 14 a distinctive color or pattern that differs from the rest of the stroller, or by using the front surfaces of the front legs 14 as a display surface for a brand or product name, the user's attention can be drawn to the stroller 1, creating a strong impression of the design and brand. Furthermore, by designing the front legs 14 as an arched shape that faces forward of the stroller body 2, the front surfaces of the front legs 14 are given a more prominent design feature. The cross-sectional shapes of the front legs 14 and rear legs 15 are examples and can be modified as appropriate. For example, the front legs 14 and rear legs 15 can be formed from tubular material with an elliptical cross-section. Even in this case, the front legs 14 can be arranged so that the direction of their larger cross-sectional dimensions corresponds to the left-right direction of the stroller body 2, and the rear legs 15 can be arranged so that the direction of their smaller cross-sectional dimensions corresponds to the left-right direction of the stroller body 2.

Next, the opening and closing locking mechanism 41 will be described in detail. FIG10 is an enlarged view of the connection portion of the front legs 14, the rear legs 15, the armrests 16, and the push frame 17, and FIG11 is a view of the portion shown in FIG10 as viewed from the oblique rear of the vehicle body 2. In addition, FIG12 and FIG13 show the state after the seat 3 is erected from the state shown in FIG10 and FIG11. The structure associated with the tilt adjustment of the seat 3 will be described in detail later. As described above, the opening and closing locking mechanism 41 is provided around the lower pin 37. One opening and closing locking mechanism 41 is provided on each of the left and right sides of the vehicle body 2, and the structures of the opening and closing locking mechanisms 41 on the left and right sides are the same.

Figure 14 is a cross-sectional view of the open/close locking mechanism 41 taken along the lower pin 37, and Figure 15 is a view of the open/close locking mechanism 41 as viewed from the oblique rear of the vehicle body 2. As clearly shown in these figures, the open/close locking mechanism 41 comprises a locking member 50 that engages with the outer periphery of the lower rod portion 30c of the handlebar 30; a wire holder 51 disposed within the lower rod portion 30c; a first retaining member 52 disposed on the inner side of the vehicle body 2 (on the right side of the drawing in Figure 14) relative to the lower rod portion 30c; a second retaining member 53; and a third retaining member 54. The lower rod portion 30c is provided with an elongated hole 30d extending along its length. The locking member 50 and the wire holder 51 are connected by a connecting pin 55 extending through the elongated hole 30d, allowing them to move together along the length of the lower rod portion 30c. The first to third retaining members 52, 53, and 54 are connected and rotatable, and are connected to the lower rod portion 30c by having the lower pin 37 pass through them. These retaining members 52, 53, and 54 are each rotatable about the lower pin 37. Furthermore, the first and third retaining members 52 and 54 are provided with recessed engagement portions 52a and 54a coaxial with the lower pin 37, and the second retaining member 53 is provided with rotatable protrusions 53a and 53b that engage with these recessed engagement portions 52a and 54a. The engagement of the recessed engagement portions 52a and 54a with the protrusions 53a and 53b suppresses any play between the first to third retaining members 52, 53, and 54, allowing them to rotate smoothly about the lower pin 37.

The rear linkage rod 36 is fixed to the first retaining member 52, and the front linkage rod 35 is fixed to the third retaining member 54. The rear linkage rod 36 also passes through the lower pin 37. Furthermore, the frame of the seat 3 is fixed to the second retaining member 53 and the third retaining member 54, which will be described in detail later. The first retaining member 52 is integrally formed with a lock receiving portion 56. The lock receiving portion 56 protrudes from the outer periphery of the first retaining member 52 and is provided with lock receiving grooves 56a at two locations on the outer periphery. The locking member 50 is provided with a locking protrusion 50a that protrudes toward the inner side of the lower rod portion 30c. The locking member 50 moves between a released position, where the locking protrusion 50a is positioned above the lock receiving portion 56, as shown in FIG16 , and a locked position, where the locking protrusion 50a is deflected below the released position. When the locking member 50 moves to the locked position, the locking protrusion 50a engages with the lock receiving groove 56a, so that the locking member 50 and the lock receiving portion 56 are engaged and cannot rotate relative to each other about the lower pin 37.

The locking member 50 is mounted on the lower rod portion 30c of the handlebar 30. The lock receiving portion 56 is rotatable with the rear linkage rod 36 about the lower pin 37. Therefore, when the locking member 50 and the lock receiving portion 56 are unable to rotate relative to each other, the handlebar 30 and the rear linkage rod 36 are also unable to rotate relative to each other about the lower pin 37. When the vehicle body 2 transforms between the deployed and folded positions, the rear linkage rod 36 rotates relative to the handlebar 30 and the rear legs 15. Therefore, when the handlebar 30 and the rear linkage rod 36 are unable to rotate relative to each other, the vehicle body 2 cannot transform. This locks the stroller 1 in either the deployed or folded position. Furthermore, as described above, the lock receiving portion 56 is provided with two lock receiving grooves 56a. In the deployed position, the locking protrusion 50a engages one lock receiving groove 56a, while in the folded position, the locking protrusion 50a engages the other lock receiving groove 56a. During the transformation between the deployed and folded positions, the locking protrusion 50a and the lock receiving groove 56a cannot engage.

In this manner, in the opening and closing locking mechanism 41, the stroller 1 is locked in the unfolded or folded state by engaging the locking protrusion 50a of the locking member 50 with the locking receiving groove 56a. The locking receiving groove 56a is located relatively close to the locking protrusion 50a relative to the lower pin 37, which serves as the rotational center of the handlebar 30 and the rear linkage rod 36. Engaging the locking member 50 and the locking receiving portion 56 near the rotational center reduces the load acting on the interlocking portion between the locking protrusion 50a and the locking receiving groove 56a. This allows for the reduction in size and weight of the locking member 50 and the locking receiving portion 56. Furthermore, the locking member 50 is switched between the released and locked positions by operating the operating handle 48 (see Figures 6 and 7) provided on the connecting portion 44 of the handlebar 31. As previously described, the operating handle 48 is connected to a connecting wire that is pulled into the push frame 17, the top end of which is connected to the connecting base 51. The connection base 51 is urged toward the locking position by a force member (not shown) such as a spring. When the operating handle 48 is operated to the left of the paper in Figure 7 against the force of the force member, the connection base 51 is pulled up, thereby moving the locking member 50 to the release position.

As shown in Figure 14, a support leg 58 and a mating block 59 fixed to the inner side of the support leg 58 are provided at the lower end of the lower rod portion 30c of the handle rod 30 (see also Figure 5). The mating block 59 projects downward from the support leg 58 toward the handle rod 30. When the stroller 1 is unfolded from the folded state to the expanded state, the support leg 58 engages with the leg receiving portion 40a of the lower bracket 40, and the mating block 59 engages with the recess 40b provided in the leg receiving portion 40a. Since the support leg 58 contacts the leg receiving portion 40a of the lower bracket 40, the handle rod 30 is blocked from below by the lower bracket 40. This allows a portion of the downward load acting on the handle rod 30 to be directly supported by the rear leg 15, and reduces the burden on the structural components of the opening and closing locking mechanism 41.

Furthermore, since the engaging block 59 fits into the recess 40b, it can restrict the positional change of the handlebar 30 relative to the rear leg 15 in the left-right direction. Therefore, even if the handlebar 30 and the rear leg 15 are connected together via multiple components, such as the lower pin 37, the rear linkage rod 36, and the rear connecting pin 39, the vehicle body 2 can be more reliably prevented from shaking in the deployed state without widening the gap between the handlebar 30 and the rear leg 15. In this way, the engaging block 59 and the recess 40b of the lower bracket 40 function as a pair of meshing portions. Alternatively, a protrusion similar to the engaging block 59 can be provided on the lower bracket 40, and a recess can be provided at the lower end of the handlebar 30, so that these components function as a pair of meshing portions. As the vehicle body 2 deforms from the folded state to the unfolded state, fingers may be pinched when the support leg 58 is embedded in the leg receiving portion 40a. In order to prevent these situations from occurring, a vertical wall portion 40c is provided on the lower bracket 40. The vertical wall portion 40c surrounds the support leg 58 from the front and left and right sides of the vehicle body 2 (see also Figures 8 and 10).

The material of the lock member 50, the first to third retaining members 52, 53, 54, the support leg 58, and the fitting block 59 can be selected as desired. However, using resin as the material for these components can reduce the weight of the vehicle body 2. Because the metal handlebar 30 and the metal rear linkage rod 36 each engage with a metal lower pin 37, the load transmission path from the handlebar 30 to the rear linkage rod 36 is formed entirely of metal. Furthermore, because the rear linkage rod 36 is connected to the rear leg 15 via a metal rear connecting pin 39, the load transmission path between the rear linkage rod 36 and the rear leg 15 is also formed of metal. Therefore, even though the first to third retaining members 52, 53, 54 of the open/close lock mechanism 41 are made of resin, the load transmission path from the handlebar 30, through the rear linkage rod 36, to the rear leg 15 is formed of metal, thereby maintaining high strength and rigidity of the vehicle body 2.

Next, let's describe the seat 3. The basic structure of the seat 3 is as follows: the seat material 61 shown in Figures 1 and 2 is attached to the seat frame 60 shown in Figures 3 and 4. As clearly shown in Figures 10 and 11, the seat frame 60 includes a seat frame 62 and a back frame 63. The seat frame 62 forms the seat structure of the seat 3, while the back frame 63 forms the back structure of the seat 3. The seat frame 62 is formed by bending a single pipe to form a pair of left and right side tubes 62a and a front tube 62b connecting the front ends of these side tubes 62a. The front tube 62b bends downward relative to the side tubes 62a and extends in the left-right direction of the vehicle body 2. The rear end of each side tube 62a is fixed to the third retaining member 54 of the opening and closing locking mechanism 41 (see Figure 15). Consequently, the seat frame 62 is integrated with the front linkage rod 35, pivoting between an expanded and folded state around the lower pin 37.

The back frame 63 also includes a pair of left and right side tubes (side members serving as back support components) 64 and a head tube (head member) 65 extending in the left-right direction of the vehicle body 2 and connecting the side tubes 64. The side tubes 64 are fixed to the second retaining member 53 of the opening and closing locking mechanism 41 (see Figure 15). Therefore, the side tubes 64 are connected to the handlebar 30 in a rotatable manner about the lower pin 37. The head tube 65 is connected to the side tubes 64 via a connecting mechanism 66. The connecting mechanism 66 includes a pair of connecting portions 66b and 66c that are connected and rotatable about a connecting pin 66a. The side tubes 64 are fixed to the lower connecting portion 66b, and the head tube 65 is fixed to the upper connecting portion 66c. This allows the head tube 65 to change its angle (inclination) relative to the side tubes 64 about the connecting pin 66a. Furthermore, the upper connecting portion 66c is connected to the upper bracket 32 via a linkage rod (linking member) 67. The front end of the linkage rod 67 is rotatably connected to the upper bracket 32 via a front pin 68, while the rear end of the linkage rod 67 is rotatably connected to the upper connecting portion 66c via a rear pin 69. The lower connecting portion 66b of the link mechanism 66 functions as part of the side tube 64, while the upper connecting portion 66c functions as part of the head tube 65. Thus, the handlebar 30, side tube 64, head tube 65, and linkage rod 67 form a four-bar linkage.

As shown in Figures 10 and 11 , when the side tubes 64 of the back frame 63 tilt rearward about the lower pins 37, the head tube 65 is pulled up relative to the side tubes 64 by the linkage rod 67 and rotates about the connecting pin 66a. Furthermore, as shown in Figures 12 and 13 , when the side tubes 64 of the back frame 63 are pulled up by the handlebar 30 about the lower pins 37, the head tube 65 is pressed by the linkage rod 67 and rotates clockwise in Figure 12 about the connecting pin 66a. Consequently, the connecting portions 66b and 66c of the connecting mechanism 66 align in a straight line, and the head tube 65 changes its inclination by bending its top end rearward relative to the extension of the side tubes 64. The clockwise rotation of the upper connecting portion 66c of the connecting mechanism 66 relative to the lower connecting portion 66b is restricted at a position slightly offset clockwise from the position shown in Figure 12 , preventing the connecting mechanism 66 from rotating further clockwise beyond this position. For example, a stopper member that limits the range of rotation may be provided between the lower connecting portion 66b and the upper connecting portion 66c, thereby limiting the rotational movement in this manner.

The seat material 61 is joined to the tubes 62a, 62b, 64, and 65 of the seat frame 60 while applying appropriate tension to these components. Figures 17 and 18 show the seat material 61 after installation. As an example, a mesh with multiple through holes can be used as the seat material 61. As clearly shown in Figures 13 and 15, the third retaining member 54 of the left and right opening and closing locking mechanism 41 is formed with a tube retaining member 54b. This tube retaining member 54b is integrally formed with the third retaining member 54. The end of a seat support tube (seat support member) 70 extending in the left-right direction of the vehicle body 2 is mounted on this tube retaining member 54b. The seat support tube 70 rotates together with the side tube 64 of the back frame 63 around the lower pin 37. In addition, the tube retaining member 54b contacts the rear linkage rod 37 from the inside in the left-right direction. This improves the left-right rigidity of the vehicle body 2.

As clearly shown in Figure 18, a connecting strap 71 is attached to the back side of the seat material 61, near the boundary between the seat frame 62 and the back frame 63. This connecting strap 71 forms a loop. By passing the seat support tube 70 through this connecting strap 71, the connecting strap 71 is secured to the seat support tube 70 with appropriate tension. Thus, the seat material 61 is clearly divided into areas corresponding to the seat portion 3a and the back portion 3b, respectively, with the attachment point of the connecting strap 71 serving as the boundary. Furthermore, a safety belt 72 for restraining infants and young children is attached to the seat material 61.

With the above-described structure of the seat 3, after the seat material 61 is affixed to the seat frame 60, accessory components such as the seat belt 72 are installed, allowing the seat 3 itself to be pre-assembled as a subassembly. The assembled subassembly seat 3 can be installed on the vehicle body 2 by securing the side tubes 62a of the seat frame 62 to the third retaining member 54 of the open/close locking mechanism 41, and the side tubes 64 of the back frame 63 to the second retaining member 53 of the open/close locking mechanism 41. Next, the seat support tube 70 is passed through the loop formed by the connecting strap 71, and the connecting mechanism 66 and the upper bracket 32 are connected via the interlocking rod 67. This clearly separates the assembly of the seat 3 from the installation of the seat 3 on the vehicle body 2, thereby improving the efficiency of the seat installation work.

Furthermore, to ensure the stability of the back 3b of the seat 3 by connecting it to the handlebar 30 and to adjust the inclination of the back 3b, a tilt adjustment strap 73 (see Figure 2) is provided on the back side of the seat 3 as a mechanism for adjusting the inclination of the back frame 63. The tilt adjustment strap 73 is arranged so as to wrap around the outer side of the back 3b of the seat 3 in the left-right direction of the vehicle body 2, with both ends secured to the handlebar 30 of the push frame 17. The length of the tilt adjustment strap 73 can be adjusted using an adjustment knob 73a. Extending the tilt adjustment strap 73 causes the back 3b to tilt, while shortening it causes the back 3b to straighten.

This allows the seat back angle of the seat 3 to be adjusted. However, the mechanism for adjusting the inclination of the back frame 63 is not limited to the inclination adjustment strap 73 and can be modified as appropriate. For example, other connecting members other than the straps can be provided between the sides of the back frame 63 and the left and right handlebars 30, each with its own adjustable length.

Next, the rear wheel 26 and its surrounding structure will be described in detail. As shown in Figures 19 and 20, a rear leg mounting portion 80 and an axle support portion 81 are integrally formed on the rear wheel retaining member 24. The rear leg mounting portion 80 is provided with a mating recess 80a, into which the lower end of the rear leg 15 engages, thereby connecting the rear leg 15 and the rear wheel retaining member 24 as a single unit. The rear cross member 19 is also fixed to the rear leg mounting portion 80. As shown in Figure 21, the axle 25 of the rear wheel 12 is mounted on the axle support portion 81. The rear wheel 26 includes a wheel body 82 made of resin and a tire 83 made of an elastic material, which is mated to the wheel body 82. The wheel body 82 includes a hub 82a, spokes 82b, and a rim 82c. To reduce weight, the number of spokes 82b is set to three (see Figure 1). For the purpose of reinforcement, a plurality of ribs 82d are provided on the rim 82c. In addition, similar to the rear wheel 26, each front wheel 22 also has a structure in which a wheel body and a tire are combined, and the number of spokes of the wheel body is three.

The hub 82a is fitted to the axle 25 via a collar 84 serving as a bearing member.

The collar 84 and hub 82a fit together and rotate together, allowing the collar 84 to rotate relative to the axle 25. Therefore, even if the axle 25 is made of metal and the wheel body 82 is made of resin, slippage occurs between the collar 84 and the axle 25, preventing wear between the hub 82a and the collar 84, or even if wear occurs, the wear rate is extremely slow. If wear or deformation of the collar 84 creates a significant gap between the axle 25 and the collar 84, simply replacing the collar 84 prevents the rear wheel 26 from shaking relative to the axle 25, or prevents any further shaking. The axle 25 is mounted on the axle support 81 with the flange 25a at one end positioned outside the rear wheel 26. The other end of the axle 25 protrudes inward from the axle support 81 and is secured by a retaining member 85, such as a retaining ring, to prevent it from falling out. A washer 86 is provided between the flange 25a of the axle 25 and the collar 84. The washer 86 prevents the rear wheel 26 from tilting relative to the axle 25. A washer 87 is provided between the fixing member 85 and the axle support 81. This washer 87 prevents wear on the facing end surfaces of the axle support 81 and the fixing member 85, thereby suppressing axial wobble of the axle 25. This improves the stability of the axle 25 and further enhances the effect of preventing the rear wheel 26 from tilting relative to the axle 25. However, if the fixing member 85 can achieve the same effect, the washer 87 can be omitted. Furthermore, the rear wheel 26 is mounted on the axle 25 in such a manner that, in the area above the axle 25, the inner end surface 82e of the hub 82a contacts the restriction surface 81a of the axle support 81. Therefore, even if only one rear wheel 26 is provided on a single rear wheel unit 12, the upper portion of the rear wheel 26 is prevented from tipping inward in the axle direction, that is, from tilting in the direction indicated by arrow A in Figure 21.

As shown in Figures 19 and 20, a rear wheel locking mechanism 90 is provided between the rear wheel 26 and the rear wheel retaining member 24 to lock the rear wheel 26 from rotation. The rear wheel locking mechanism 90 comprises an operating pedal (locking operating member) 92 rotatably mounted on the rear wheel retaining member 24 about a pin 91 serving as a rotation axis, and multiple protrusions 93 disposed inside the hub 82a of the rear wheel 26. The protrusions 93 are integrally formed with the wheel body 82 and constitute a portion of the hub 82a. The end surface 82e of the hub 82a is formed by the end surfaces of these protrusions 93. As shown in Figure 22, the multiple protrusions 93 are arranged at regular intervals around the axle 25. Figure 22 shows the relationship between the operating pedal 92 and the protrusions 93 as viewed from a direction parallel to the axle 25. The right side of the drawing corresponds to the rear of the vehicle body 2.

Each protrusion 93 has: a base 93a, which extends in the radial direction of the hub 82a; and an enlarged portion 93b, which is arranged on the outer peripheral side of the base 93a. In addition, a cylindrical stop pin (stop portion) 92a is provided on the operating pedal 92. A pair of operating portions 92b and 92c are provided on the surface of the operating pedal 92. When the user operates by selectively stepping on these operating portions 92b and 92c, the operating pedal 92 swings like a seesaw with the pin 91 as the center. When the operating portion 92b located on the left side of the paper of Figure 2 is stepped on, the operating pedal 92 rotates counterclockwise with the pin 91 as the center, moves to the lock release position shown by the solid line, and the stop pin 92a moves backward away from the protrusion 93 (protrusion 93). When the operating portion 92c located on the right side of the drawing in Figure 2 is stepped on, the operating pedal 82 rotates clockwise about the pin 91, moving to the locked position. This causes the stop pin 92a to engage with the pin receiving groove 94 formed by the gaps between the protrusions 93. In this state, regardless of whether the rear wheel 26 is rotating forward or backward, the protrusions 93 and the stop pin 92 engage circumferentially with each other around the axle 25, restraining the wheel hub 82a circumferentially and preventing the rear wheel 26 from rotating. The enlarged portion 93b provided on the outer circumference of the protrusion 93 prevents the stop pin 92a from falling out due to the torque acting on the rear wheel 26. By establishing the following relationship between the stop pin 92a and the protrusion 93, the stop pin 92a can be reliably prevented from falling out.

As shown in Figure 23, the arc described by the center position SC of the stop pin 92a with the axle 25 as the center is defined as the rotational trajectory C1 of the protrusion 93, and the arc described by the center position SC of the stop pin 92a with the pin 91 as the rotation axis as the rotational trajectory C2 of the stop pin 92a. When tangent lines α and β are drawn from the intersection P of these rotational trajectories C1 and C2, the relationship between the stop pin 92a and the protrusion 93 is set so that the angle θ between these tangent lines α and β is approximately 90°. Therefore, when the stop pin 92a is engaged in the pin receiving groove 94, even if a moment in either the forward or reverse direction acts on the rear wheel 26, a thrust is applied between the protrusion 93 and the stop pin 92a along the tangent line α, and the force component in the direction of pushing the stop pin 92a out of the pin receiving groove 94 is either negligible or minimal. Therefore, the rear wheel locking mechanism 90 can reliably exert its locking effect on the rear wheel 26. Furthermore, regarding the angle θ, as long as a force component sufficient to push the stopper pin 92a out of the pin receiving groove 94 is not generated, a range of tolerances relative to 90° can be set. "Approximately 90°" means that such a range (permissible range) is included.

In addition, the outer peripheral side of the enlarged portion 93b provided on the protrusion 93 of the hub 82a is tapered toward the top. This tapered shape allows the stop pin 92a to easily fit into the pin receiving groove 94. Furthermore, a hole 92d is formed between the operating portions 92b and 92c of the operating pedal 92. The rear wheel retaining component 24 is provided with at least one of the following markings: a lock marking that appears within the hole 92d when the operating pedal 92 is in the locked position; and a lock release marking that appears within the hole 92d when the operating pedal 92 is in the unlocked position. By confirming these markings, the user can determine whether the rear wheel 26 is locked or rotating.

Figures 24 and 25 show axle caps 100. These caps are optionally installed on the outer sides of the front wheel 22 (but only on the outer front wheel) and rear wheel 26 for decorative purposes. Figures 4 and 19 show the end caps 100 installed. The front and rear wheel end caps 100 differ in size but have the same structure. Therefore, the following description will use the end cap 100 for the rear wheel 26 as an example. The end cap 100 has a disc-shaped outer shape with a through-hole 101 formed in its center. On the back side of the axle cap 100 (the side shown in Figure 25 ), there are ribs 102 that fit along the inner circumference of the rim 82c of the rear wheel 26 and a plurality of claws 103 that protrude from these ribs 102. The axle cap 100 is attached to the rear wheel 26 by securing the claws 103 to the inner side of the rim 82c. When the axle cover 100 is mounted on the rear wheel 26, the claw portion 103 is hidden on the back side of the axle cover 100 and is therefore not visible to the user. Therefore, when the axle cover 100 is subjected to surface treatment for the purpose of improving functionality, such as electroplating treatment for the purpose of improving appearance or coating treatment for the purpose of improving wear resistance, the claw portion 103 can be excluded from the scope of the treatment object. Therefore, problems associated with surface treatment, such as poor meshing and embrittlement due to dimensional changes, or increased risk of breakage due to reduced elasticity, can be prevented. When surface treatment is performed by immersing the claw portion 103 in a treatment liquid such as an electroplating solution, there is no need to immerse the claw portion 103 in the treatment liquid. Therefore, there is no need to mask the claw portion 103, which can reduce working hours.

Figure 26 shows the footrest 18. The footrest 18 is provided as a place for infants and young children sitting on the seat 3 to place their feet. It also serves as a component that connects the left and right front legs 14 and reinforces the vehicle body 2 in the left-right direction. The footrest 18 is a resin molded product. Leg-engaging holes 18a are provided at both ends of the footrest 18 for the front legs 14 to pass through. A footrest surface 18b is formed between the leg-engaging holes 18a for placing the feet. The footrest surface 18b is configured as a stepped surface by making the rear portion 18d lower than the front portion 18c. By configuring the footrest surface 18b as such a stepped surface, the apparent width of the footrest 18 in the front-to-back direction of the vehicle body 2 can be reduced. Figure 27 shows the structure of the back side of the footrest 18. To provide the footrest 18 with the required strength, ribs 18e are formed on the back side of the footrest 18 in the vertical and horizontal directions as needed. The ribs 18e can also be arranged differently. The ribs 18e can be limited to locations where they are required to increase strength or rigidity.

Figure 28 is an enlarged view of the sunshade 4 and its surroundings, and Figure 29 is an enlarged view of the portion where the sunshade 4 is mounted on the push frame 17. The sunshade 4 includes a sunshade support mechanism 110 and a sunshade body 111. As shown in Figure 29, the sunshade support mechanism 110 comprises a pair of sunshade brackets (only one side is shown in Figure 29) 112 mounted on the left and right handlebars 30 of the push frame 17; a pair of sunshade bases 113 detachably mounted on the sunshade brackets 112; and a sunshade support rod 114 disposed between the pair of sunshade bases 113 (see also Figure 4). The sunshade base 113 includes a mounting portion 113a mounted on the sunshade brackets 112 and a rotating portion 113c mounted on the mounting portion 113a and rotatable about a pin 113b. The mounting portion 113 a can be removed from the sun visor bracket 112 by pushing the operating handle 113 d .

The mounting portion 113a and the rotating portion 113c are both made of resin. A position-holding mechanism (not shown) is provided between the mounting portion 113a and the rotating portion 113c. This position-holding mechanism utilizes the elasticity of the resin to selectively hold the rotating portion 113c in one of a plurality of stop positions within its rotation range. The position-holding mechanism is constructed, for example, as follows: between the opposing surfaces of the mounting portion 113a and the rotating portion 113c, convex and concave portions are alternately formed around the axis of the rotating portion 113c, i.e., the pin 113b, as the center. The rotating portion 113c is stopped by embedding one facing convex portion into the concave portion of the other opposing surface. When the stop position of the rotating portion 113c is changed, the convex portions on both opposing surfaces undergo elastic changes. When the position-holding mechanism adopts such a structure, the rotation of the rotating portion 113c is restricted, thereby allowing these concave and convex portions to function as a position-holding mechanism. A support rod engaging portion 113e is integrally formed on the rotating portion 113c.

The sunshade support rod 114 is a strip-shaped member made of resin, with both ends fixed to the support rod engaging portions 113e of the left and right sunshade bases 113. This supports the sunshade support rod 114 in an upwardly curved position between the sunshade bases 113. The sunshade support rod 114 is held in one of a plurality of stop positions, including an extended position when the sunshade 4 is extended and a stowed position when the sunshade 4 is folded, by a position retaining mechanism built into the sunshade bases 113.

The sunshade body 111 comprises a sunshade canopy 115 formed by cutting sunshade material into a suitable shape, and a plurality of resin sunshade ribs 116 mounted at appropriate locations on the inner surface of the sunshade 115. The sunshade is made of an elastic material. The front end of the sunshade 115 is connected to the sunshade support rod 114 by tucked inside the sunshade support rod 114. When the sunshade 115 of the sunshade 4 is deployed, as shown in Figure 28, the sunshade ribs 116 are positioned at appropriate intervals in the front-to-back direction of the vehicle body 2, thereby securing the sunshade 115. The ends of the sunshade ribs 116 converge near the sunshade base 113 but are not fixed to the sunshade base 113.

On both sides of the awning 115 are provided winding portions 117 that can be wound around the handlebar 30 of the push frame 17. The connection position of the winding portions 117 to the awning 115 corresponds to the position of the third sunshade rib 116 from the front end of the awning 115. By winding the left and right winding portions 117 around the handlebar 30, the winding portions 117 and the awning 115 are secured relative to each other using a pair of upper and lower snap fasteners 118. This allows the third sunshade rib 116 to be held along the handlebar 30 while the two sides of the awning 115 are connected to the handlebar 30. Furthermore, on both sides of the awning 115, at the locations where the sunshade ribs 116 converge, buckle portions 115a are provided that can be secured to the mounting portion 113a (or alternatively, the rotating portion 113c) of the sunshade base 113. By fixing the buckle portion 115a to the mounting portion 113a, both ends of each sunshade rib 116 are fixed substantially near the mounting portion 113a.

Furthermore, an extension portion 115b is provided at the rear end of the awning 115, facing the rear of the vehicle body 2. The extension portion 115b is sewn into a bag-like shape, and its rear end covers the back of the seat 3 when the back 3b is folded down (see also FIG6 ). Thus, even when the back of the seat 3 is folded down, the awning 115 covers the upper portion of the back 3b of the seat 3. Furthermore, a connecting member, such as a snap fastener, is provided between the extension portion 115b and the back 3b of the seat 3, allowing the seat 3 and the awning 115 to be connected.

In the sunshade 4 described above, the sunshade rod 114 of the sunshade support mechanism 110 pivots about the pin 113b of the sunshade base 113, switching the sunshade 115 between a folded and unfolded state. In the unfolded state, the sunshade rod 114 is held in a position protruding approximately horizontally forward of the handlebar 30 by a position-holding mechanism within the sunshade base 113. This stretches the sunshade 115 in the front-to-back direction, applying appropriate tension. Furthermore, by retaining the third sunshade rib 116 along the handlebar 30 via the winding portion 117 and securing the buckle portion 115a to the sunshade base 113, both ends of each sunshade rib 116 are held approximately near the sunshade base 113. Consequently, there is no need for additional structure to attach the sunshade rib 116 to the sunshade base 113 to maintain these components in a fixed position. Furthermore, even without providing other components such as a frame or springs to maintain a constant distance between the sunshade support rods 114 and the sunshade ribs 116 or between the sunshade ribs 116 in the front-to-back direction, the elasticity of the sunshade 115 can be utilized to maintain the sunshade 115 in a substantially constant expanded shape. This can reduce the number of components of the sunshade 4.

Referring to Figures 1 to 5 , the storage basket 5 is formed by sewing a material such as mesh into a box shape. The storage basket 5 is suspended from the vehicle body 2 using connecting straps 120 located at the four corners of its upper edge. As shown in Figure 8 , the front side of the storage basket 5 is suspended from the front connecting pin 38 connecting the front linkage rod 35 and the front leg 14 using the connecting strap 120. The rear side of the storage basket 5 is suspended from the rear connecting pin 39 connecting the rear linkage rod 36 and the rear leg 15 using the connecting strap 120. Figures 30 and 31 show the detailed structure of the connecting strap 120. The base 120a at one end of the connecting strap 120 is sewn to the storage basket 5, securing the connecting strap 120 to the upper edge of the storage basket 5. By bending the connecting strap 120 and sewing it together, a stopper 120b is formed at the top end of the connecting strap 120, protruding from both the front and back sides of the connecting strap 120. A hook 121 is secured to the base 120a of the connecting strap 120 via a loop 122. The loop 122 is sewn to the base 120a of the connecting strap 120 and is also sewn to the storage basket 5 at a predetermined connection point SP. A notch 121a is formed at the tip of the hook 121, through which the connecting strap 120 passes.

Therefore, after wrapping the connecting strap 120 around the front connecting pin 38 and the rear connecting pin 39 and then folding it back, the portion closer to the base 120a than the stopper 120b is inserted through the cutout 120a into the hook 121. This causes the stopper 120b to engage with the hook 121, preventing the connecting strap 120 from falling out of the hook 121. The connecting strap 120 thus allows the storage basket 5 to be suspended from the front connecting pin 38 and the rear connecting pin 39. Since the stopper 120b is formed by overlapping and connecting the connecting strap 120 itself, the number of components required for assembling the storage basket 5 can be reduced compared to a case where other components are attached to the connecting strap 120 to function as stoppers.

Next, the structure for preventing finger pinching in the armrest 16 and its surroundings will be described in detail. Figure 32 is an enlarged side view of the armrest 16 and its surroundings in the folded state. Figure 33 is a front view taken from the direction indicated by arrow XXXII in Figure 32. Figure 34 is a cross-sectional view taken along line XXXIV-XXXIV in Figure 32. As clearly shown in Figure 32, in the folded state of the stroller 1, the handle connecting portion 16b is tilted downward relative to the leg mounting portion 16a, contrary to the unfolded state. In this situation, the front legs 14 and rear legs 15 are close together around the leg mounting portion 16a, and the armrest 16 is covered by the rear legs 15. Therefore, when the stroller 1 is deformed from the unfolded state to the folded state, if a user inadvertently places their fingers around the fulcrum pin 39, they could be pinched. Therefore, as described above, the front legs 14 are offset forward of the fulcrum pin 29 relative to the rear legs 15 and connected to them, thereby maintaining a gap S1 between the front and rear legs 14 and 15 in the folded state. The size of the gap S1 is set to be greater than the minimum value of the gap required to prevent fingers from being pinched (hereinafter referred to as the required gap). The required gap can be set to a certain safety value estimated based on the estimated range of the thickness of the user's fingers. In the case where a required gap is specified according to standards other than the safety standards for baby strollers, this value can be used as the required gap. For example, to determine whether a gap greater than the required gap is ensured, imagine an arc with the required gap as the diameter. If there is a gap containing the arc in the folded state, it can be determined that a gap greater than the required gap is ensured. In addition, in Figure 32, a circle formed by a dotted line is used to indicate the approximate position of the gap S1. Below, the same circle is used to indicate other gaps in each figure. However, the circle in the figure only indicates the position of the gap and does not indicate the range or amount of the gap.

As clearly shown in Figures 33 and 34 , the armrest 16 comprises the aforementioned top panel 16c and a pair of side panels 16d and 16e extending from the side edges of the top panel 16c, facing the left and right sides of the vehicle body 2. The interior of the armrest 16, enclosed by the top panel 16c and the side panels 16d and 16e, is hollow. This hollow opens toward the lower surface of the armrest 16, in other words, toward the side facing the rear legs 15. This allows the rear legs 15 to fit within the armrest 16 when folded. To prevent fingers from being pinched between the armrest 16 and the rear legs 15, the side panels 16d and 16e of the armrest 16 are positioned asymmetrically with respect to the widthwise centerline CL1 of the rear legs 15. First, the side panels 16d on the outer sides of the stroller 1 are designed to bulge outward from the rear legs 15, with the distance from the centerline CL1 to the side panels 16d being greater than the distance from the centerline CL1 to the side panels 16e. Thus, when a portion of the rear legs 15 is inserted into the armrests 16, a gap S2 greater than or equal to the required gap is maintained between the rear legs 15 and the side panels 16d. Therefore, even if a user places a finger inside the side panels 16d of the armrests 16 when folding the stroller 1, the finger will not be caught between the rear legs 15 and the side panels 16d.

Furthermore, the inner side panel 16e is closer to the centerline CL1 than the side panel 16d. This is because the inner position of the side panel 16e makes it difficult to predict the possibility that a user will place their fingers on the inner surface of the side panel 16e when folding the seat. Furthermore, if the inner side panel 16e of the armrest 16 protrudes excessively from the seat 3, the space on the seat 3 is compressed in the left-right direction, impairing the comfort of the infant or young child. In the folded state, the lower bracket 40 on the rear leg 15 approaches the armrest 16. In particular, the leg receiving portion 40a (see FIG. 8 ) moves over the side panels 16d and 16e until it substantially enters the interior of the armrest 16. Therefore, as shown in FIG. 34 , a gap S3 greater than the required clearance is ensured between the top panel 16c and the leg receiving portion 40a. Furthermore, as shown in FIG. 35 and FIG. 36 , a recess 16f is formed in the side panel 16e to align with the position of the lower bracket 40 in the folded state. Thereby, the gap S3 is passed to the outside of the armrest 16, more specifically, the outside of the side plate 16e through the recess 16f. In addition, the recess 16f is not limited to the position of the leg receiving portion 40a and can be provided at an appropriate position of the side plate 16e as required.

As shown in FIG35 , the upper pin 34 connecting the handle connecting portion 16b of the armrest 16 and the upper bracket 32 on the handlebar 30 is offset forward of the lower rod portion 30c of the handlebar 30. Therefore, even in the folded state, a gap S4 greater than the required clearance is maintained between the top plate 16c of the armrest 16 and the lower rod 30c of the handlebar 30.

In addition to the aforementioned gaps S1 to S4, the stroller 1 also has gaps S5 to S14, each larger than the required amount, to prevent fingers from being pinched. These gaps are described below. As shown in Figure 35 , a gap S5 is provided between the sunshade base 113 of the sunshade support mechanism 110 and the top plate 16c of the armrest 16. As shown in Figure 33 , the linkage rod 67 of the back frame 63 on the seat frame 60 is bent into two sections in the left-right direction between its ends, thereby ensuring a gap S6 between the end on the front pin 68 side and the side tube 64, and a gap S7 between the end on the rear pin 69 side and the sunshade base 113 and sunshade support rod 114. The ends of the linkage rod 67 are further bent in the front-to-back direction relative to the middle portion, thereby ensuring a gap S8 centered around the front pin 68 and a gap S9 centered around the rear pin 69.

Figure 37 shows the area around the lower pin 37 as viewed from the direction of arrow XXXVII in Figure 5 , and Figure 38 shows the area around the lower pin 37 as viewed from the inside of the stroller 1 . As shown in these figures, clearance exceeding the required amount is ensured at several locations around the lower pin 37. As described above, the first, second, and third retaining members 52, 53, and 54 are sequentially mounted along the axis of the lower pin 37. The rear interlocking rod 36 is secured to the first retaining member 52, the side tube 64 of the back frame 63 is secured to the second retaining member 53, and the side tube 62a of the seat frame 62 is secured to the third retaining member 54. In the left-right direction of the stroller 1 (the axis of the lower pin 37), the handlebar 30 and the rear leg 15 are positioned in the same position. The rear interlocking rod 37 extends straight from the first retaining member 52 and is connected to the rear leg 15 via the rear connecting pin 39. Therefore, a gap S10 is provided between the rear leg 15 and the rear interlocking rod 37. Furthermore, to maintain the gap S10, a washer 39a is fitted around the outer periphery of the rear connecting pin 39. Furthermore, based on the axial thickness of the first retaining member 52 and the second retaining member 53, a gap S11 is ensured between the rear interlocking rod 36 and the second retaining member 53, and a gap S12 is ensured between the rear interlocking rod 36 and the side tube 64.

To ensure the width of the seat 3, the side tubes 62a of the seat frame 62 connected to the third holding member 53 are bent so as to protrude outward in the left-right direction from the connection portion with the third holding member 54. However, the amount of this bending is limited so as to provide a gap S13 between the side tubes 62a and the handlebar 30. Furthermore, as clearly shown in FIG. 38 , a gap S14 is also provided between the connection portion of the side tubes 64 to the second holding member 53 and the connection portion of the side tubes 62a to the third holding member 54.

Next, we will explain how the back portion 3b (see Figure 1) is stowed when the stroller 1 is in the folded position. As shown in Figure 5 , when the stroller 1 is in the folded position, the back portion 3b of the seat 3 (in other words, the back portion 3b of the seat 3) can be moved to a stowed position, where it is erected against the handlebar 30 of the body 2. Figures 39 to 41 illustrate a state in which the back portion 63 is stowed against the handlebar 30 when the stroller 1 is in the folded position. However, Figure 39 shows the back portion 63 in its extended position, tilted backward. As described above, the side tubes 64 of the back portion 63 are connected to the handlebar 30 and rotate relative to the handlebar 30 about the lower pin 37. Therefore, if some method is not employed to restrict the rotation of the back portion 63 when the stroller 1 is moved to the stowed position, the back portion 3b may naturally fall back into the extended position. Next, the structure for maintaining the back portion 63 in the stowed position will be described with reference to Figure 42 .

Figure 42 schematically illustrates the back frame 63 as a four-bar linkage. Point A represents the connecting pin 66a, point B represents the rear pin 69, point C represents the front pin 68, and point D represents the lower pin 37. Point D corresponds to the back connection point, point A corresponds to the head connection point, point C corresponds to the front connection point, and point B corresponds to the rear connection point. First, when points CD, which are attached to (located on) the same handlebar 30, are fixed, point A describes a rotational trajectory A centered around point D, and point B describes a rotational trajectory B centered around point C. Furthermore, point B rotates relative to point A. However, the rotational movement of point B relative to point A is limited. Specifically, when the back frame 63 is moved from the extended position to the stowed position Ps, rotational movement about point B is permitted until the back frame 63 reaches the limit position Px, where the head tube 65 is slightly tilted rearward, from the position where the connection between the side tubes 64 and the head tube 65 is aligned. When the back frame 63 moves beyond the restricted position Px to the area toward the stowage position Ps, its rotational motion is restricted between the connecting portions 66b and 66c of the connecting mechanism 66, preventing point B from rotating relative to point A. In Figure 42 , when point B reaches position P1, the back frame 63 is at the restricted position Px. The position of point B at this point is referred to as the restricted starting point P1. At the restricted starting point P1, point B is defined as the intersection of two different trajectories: a rotation trajectory Bt centered on point C and a rotation trajectory Dt centered on point D. Therefore, if the back frame 63 were a fully rigid body, point B would not be able to move beyond the restricted starting point P1 toward the stowage position Ps. However, since the back frame 63 is not actually a fully rigid body, point B can be moved beyond the restricted starting point P1 by, for example, elastically deforming the linkage rod 67. The greater the distance between the trajectories Bt and Et, the greater the amount of elastic deformation.

As clearly shown in Figure 42, the rotational trajectories B and E also intersect at an inflection point P2, which is not the restriction start point P1. The position where this inflection point P2 and point B coincide is the stowed position Ps of the back frame 63. When point B is at inflection point P2, the back frame 63 is released from its elastic deformation, similar to when it is at the restriction start point P1. When point B moves beyond inflection point P2 and further to the left in Figure 42 (i.e., in the direction of further stowing the back frame 63), the rotational trajectories Bt and Et diverge again, causing the back frame 63 to elastically deform. That is, with inflection point P2 as the boundary, the back frame 63 will elastically deform regardless of the direction in which point B moves, and the restoring force against this elastic deformation acts in the direction that pulls point B back toward the inflection point P2. Thus, when point B coincides with inflection point P2, the position of the back frame 63 is set to the stowed position Ps. Specifically, when the back frame 63 moves to the stowed position Ps, point B coincides with inflection point P2, thereby maintaining the back frame 63 in the stowed position Ps. When point B is between the restriction start point P1 and inflection point P2, as clearly shown by the difference between the trajectories Bt and Et, the elastic deformation of the back frame 63 reaches its maximum at the midpoint between points P1 and P2. As point B moves beyond this midpoint toward inflection point P2, the elastic deformation gradually decreases. The restoring force associated with the elastic deformation acts in a direction that reduces the elastic deformation. Therefore, if point B moves beyond the midpoint between points P1 and P2 toward point P2, a force is applied to the back frame 63, causing it to move toward the stowed position Ps. Therefore, if a stopper is added to the vehicle body 2 to restrict the back frame 63 from moving toward the stowed position Ps, at any point between the midpoint between points P1 and P2 and the inflection point P2, the back frame 63 will be pushed toward the stopper due to the elastic restoring force generated within the back frame 63. Even when this position is set to the stowed position Ps, the back portion frame 63 can be held at the stowed position Ps by the restoring force generated by the elastic deformation.

Furthermore, the restricted position Px of the back frame 63 is set outside the range within which the inclination of the back frame 63 can be adjusted (the range of movement of the back portion 3b) in the unfolded state of the vehicle body 2. Specifically, as long as the inclination of the back portion 3b in the unfolded state is adjusted, the rotation between the connecting portions 66b and 66c of the connecting mechanism 66 is not restricted. When the back frame 63 is slightly raised forward from the extended position shown in FIG39 in the folded state, the connecting portions 66b and 66c of the connecting mechanism 66 are connected around the connecting pin 66a, so that the back frame 63 reaches the restricted position. Furthermore, as shown in FIG39 to FIG41 , in addition to the gaps S8 and S9 already described, the back frame 63 is provided with a gap S15 centered around the connecting pin 66a of the connecting mechanism 66 and a gap S16 centered around the lower pin 37, providing a gap greater than the required clearance to prevent fingers from being pinched.

FIG43 is a diagram showing the stroller 1A according to the modified example, which corresponds to FIG4 . The stroller 1A differs from the stroller 1 in the following respects: in the back frame 63 of the seat 3, the side tubes 64 and the head tube 65 are formed as one piece, the connecting mechanism 66 and the linkage rod 67 shown in FIG10 to FIG13 are omitted, and the handlebar 30 and the hand grip 31 are connected in a manner that cannot adjust the angle, and the connector 45 is removed. The stroller 1A is the same as the stroller 1 in other respects. Therefore, in FIG42 , the same reference numerals as in FIG4 are used to represent the same parts as those in the stroller 1, and their description is omitted. In addition, as in FIG1 and FIG2 , in the stroller 1A, the seat material is attached to the seat frame, and the sunshade and the storage basket are installed.

The present invention is not limited to the above-mentioned manner and its variations, and can also be implemented in various other manners. For example, the sunshade 4 and the bracket 5 can be omitted, and the structure of the seat 3 is not limited to the above-mentioned manner. Seats of various structures equipped with known baby strollers can be installed on the body. The structure of the front wheel portion and the rear wheel portion is also not limited to the above-mentioned manner. For example, the rear wheel portion can be a two-wheeled type. The lower rod portion of the handle bar can be further bent more than once between the bend and its lower end. The opening and closing locking mechanism can be provided in a manner that replaces the rear linkage component or locks the relative rotation of the front linkage component and the handle bar together with the rear linkage component. The locking component of the opening and closing locking mechanism is not limited to being switched between the locked position and the released position by remote operation of the opening and closing operating portion. The opening and closing locking mechanism can be constructed in a manner that the user directly operates the left and right locking components. A locking receiving groove can be provided on the locking component, and a locking protrusion can be provided on the locking receiving portion.

The present invention is not limited to the above-mentioned embodiment and its variations, and can also be implemented in various other embodiments. For example, in the above-mentioned embodiment, the wheel device involved in the present invention is applicable to the rear wheel, but the present invention is not limited to the rear wheel, and can also be applied to the front wheel. The cart to which the present invention is applicable is not limited to the baby cart in the above-mentioned embodiment, and can also be applied to baby carts with different body structures, and can also be applied to carts with different uses from baby carts. The wheel device of the present invention is not limited to mounting one wheel on one wheel retaining component via an axle. Even when multiple wheels are mounted on the same axle, the rotation of some or all wheels can be locked according to the present invention. The present invention is not limited to four-wheeled carts, and can also be applied to carts with three wheels or less than three wheels, or five wheels, or more than five wheels.

The present invention is not limited to the above-mentioned manner and its variations, and can also be implemented in various other manners. For example, a seat material is attached to the seat frame and the back frame to form the seat as a subassembly. As long as the formation of the seat is not hindered, a front tube and a head tube can be provided on the seat frame and the back frame. In addition, a reinforcing material connecting the side tubes in the left and right directions can be appropriately provided. For example, the present invention can be applied to a stroller in which the extension line of the handlebar is directed toward the rear wheel side. The present invention can also be applied to a stroller in which the body cannot be folded. The seat of the present invention can also be applied to a stroller without a sunshade. The bracket can be omitted. The structure of the front wheel and the rear wheel is also not limited to the above-mentioned manner. For example, the rear wheel can also be a two-wheeled type, and the seat and sunshade of the present invention can be applied to a three-wheeled stroller in which the front wheel is arranged in the center of the body.

The present invention is not limited to the above-mentioned manner and its variations, and can also be implemented in various other manners. For example, the present invention is not limited to foldable baby strollers, and can also be applied to baby strollers with non-foldable bodies. The present invention can also be applied to baby strollers in which the extension line of the handlebar is directed toward the rear wheel side. The structure of the seat is not limited to the above-mentioned example, and can be appropriately modified. The sunshade and the storage basket can be omitted. The structure of the front wheel part and the rear wheel part is also not limited to the above-mentioned manner. For example, the rear wheel part can also be a two-wheeled type. The present invention is not limited to a four-wheeled baby stroller in which the front legs and the rear legs are respectively arranged on the left and right sides of the body, and can also be applied to a three-wheeled baby stroller in which the front wheel is arranged in the center of the body.

The present invention is not limited to the above-mentioned manner and its variations, and can also be implemented in various other manners. For example, the baby stroller of the present invention is not limited to the following structure: in the unfolded state, the upper rod portion of the handlebar, the armrest and the front leg are roughly extended in a straight line. The present invention can also be applied to the following baby stroller: the armrest is configured to extend roughly horizontally or slowly tilted upward from the connection point with the upper end portion of the front leg to the rear. The structure connecting the handlebar and the rear leg is also not limited to the above-mentioned manner. As long as it has the following structure, various deformations can be made to the structure for folding the baby stroller: in the folded state, the armrest is tilted obliquely downward from the front end portion to the rear end portion along the rear leg, so that the lower surface side of the armrest is close to the rear leg, or a part of the rear leg is on the lower surface side of the armrest.

The present invention is not limited to the above-described embodiment and its variations and may be implemented in various other embodiments. For example, in the above-described embodiment, rotational movement is restricted in the region from the restricted position to the stowed position around pin 66a of connecting mechanism 66, in other words, around head connection point A. However, rotational movement may instead be restricted around rear pin 69, in other words, around rear connection point B. In this case, pin 66a describes a rotational trajectory around lower pin 37 and front pin 68, respectively, and the stowed position is set based on these rotational trajectories, as shown in FIG42 . The back support member of the back is not limited to tubular side members; other suitable plate-shaped members may be employed. A single back support member may be rotatably connected to vehicle body components such as left and right handlebars at the back connection points. In the above-described embodiment, the back is configured so that a four-bar linkage is formed on each of the left and right edges of the back. However, the four-bar linkage may be formed on either side. Even if a four-bar linkage is provided on both sides, rotational movement around a single connection point on the head member may be restricted on either side. However, when rotational movement is restricted on both sides, it is preferred that an equal effect of retaining the back in the stowed position is produced on both sides of the backrest, thereby more reliably achieving the back-holding effect. The vehicle body is not limited to the example obtained by the above-mentioned frame structure. As long as the seat back is attached to the vehicle body in a manner that forms a four-bar mechanism, the structure for folding the vehicle body can be variously modified, and the structure is not necessarily limited to a frame structure. The present invention is not limited to four-wheeled strollers and can also be applied to three-wheeled strollers with a single front wheel.

[Description of Reference Numerals]

1. 1A: Stroller; 2: Carriage; 3: Seat; 3a: Seat; 3b: Back; 4: Sunshade; 5: Storage basket; 10: Frame; 11: Front wheel; 12: Rear wheel; 14: Front legs; 15: Rear legs; 16: Armrest (intermediate linkage component); 16c: Top plate; 16d: Outer side panel; 16e: Inner side panel; 17: Push frame; 18: Footrest; 18b: Footrest surface; 1 8e: Rib; 19: Rear cross member; 21: Axle; 22: Front wheel; 23: Locking handle; 24: Rear wheel holding member (wheel holding member); 25: Rear wheel; 25: Axle; 26: Rear wheel; 29: Pivot pin; 30: Handlebar; 30a: Bend; 30b: Upper rod; 30c: Lower rod; 31: Hand grip; 32: Upper bracket; 34: Upper pin; 35: Front linkage rod (front : linkage component); 36: rear linkage rod (rear linkage component); 37: lower pin (back connection point); 38: front connecting pin; 39: rear connecting pin; 40: lower bracket; 40a: leg receiving portion; 40b: recess; 40c: vertical wall portion; 41: opening and closing locking mechanism; 42: connecting portion; 43: hand grip portion; 44: contact portion; 45: connector; 48: operating handle; 50: locking component; 50a: locking protrusion; 52: 1st holding component; 53: 2nd holding component; 54: 3rd holding component; 55: connecting pin; 56: locking receiving portion; 56a: locking receiving groove; 58: support leg; 59: fitting block; 60: seat frame; 61: seat material; 62: seat frame; 62a: seat frame; 62b: front tube; 63: back frame; 64: side tube (back support component, side Component); 65: Head pipe (head component); 66: Connecting mechanism; 66a: Connecting pin (head connection point); 67: Linking rod (linking component); 68: Front pin (front connection point); 69: Rear pin (rear connection point); 70: Seat support tube (seat support component); 71: Connecting belt; 80: Rear leg mounting portion; 81: Axle support portion; 81a: Restriction surface; 82: Wheel body; 82a: Wheel hub ; 82b: spoke; 82c: rim; 82e: end face of hub; 84: collar (bearing component); 85: fixing component; 86: washer; 90: rear wheel locking mechanism; 91: pin (rotational axis); 92: operating pedal (locking operating component); 92a: stop pin (stop portion); 93: protrusion; 93a: base; 93b: enlarged portion; 94: pin receiving groove; 100: shaft cover; 103: Claw; 110: sunshade support mechanism; 111: sunshade body; 112: sunshade bracket; 113: sunshade base; 113a: mounting portion; 113c: rotating portion; 114: sunshade support rod; 115: sunshade; 115a: buckle portion; 116: sunshade rib; 117: winding portion; 118: snap buckle; 120: connecting belt; 120a: base; 120b: stopper; 1 21: Hook; 121a: Incision; 122: Belt; C1: Rotational trajectory of the protrusion; C2: Rotational trajectory of the stop pin; EL: Extension line of the upper rod portion of the handlebar; HP: Imaginary horizontal plane containing the axle axis of the front wheel; S1~S16: Gaps larger than the required amount; SP: Connection position of the connecting belt; VA: Rotational axis of the front wheel; α, β: Tangents of the rotational trajectory; θ: Angle between the tangents.

Claims (4)

1. A stroller comprising: a frame (2) including front legs (14) and rear legs (15); a handlebar (30) disposed at the rear of the frame (2) for transmitting a user's operating force to the frame (2), the lower end of the handlebar (30) being connected to the rear legs (15), wherein the front legs (14) and the rear legs (15) have cross-sectional shapes in a direction with a larger cross-sectional dimension and a direction with a smaller cross-sectional dimension, characterized in that, In this stroller, the front legs (14) are configured such that the direction with the larger cross-sectional dimension is in the left-right direction of the body (2), and the rear legs (15) are configured such that, unlike the front legs (14), the direction with the smaller cross-sectional dimension is in the left-right direction of the body (2). The stroller also features a central linkage component (16), a front linkage component (35), and a rear linkage component (36). One end of the intermediate linkage component (16) is connected to the upper end of the front leg and the rear leg respectively and can rotate, and the other end is connected to the handle and can rotate; One end of the front linkage component (35) is connected to the handle bar at a position (37) lower than the connection point (34) between the handle bar and the intermediate linkage component and is rotatable; the other end is connected to the front leg at a position (38) lower than the connection point (29) between the front leg and the intermediate linkage component and is rotatable. One end of the rear linkage component (36) is connected to the handle bar at a position (37) lower than the connection point between the handle bar and the intermediate linkage component, and is rotatable thereon. The other end is connected to the rear leg at a position (39) lower than the connection point (29) between the rear leg and the intermediate linkage component, and is rotatable thereon. By rotating the front legs, the rear legs, the handle, the middle linkage component, the front linkage component, and the rear linkage component relative to each other around their respective connection points, the stroller can be deformed between an unfolded state and a folded state. 2. The stroller according to claim 1, characterized in that the handle bar (30) and the rear leg (15) are configured such that the rear leg (15) blocks the lower end of the handle bar (30) from below. 3. The stroller according to claim 1, characterized in that, in the cross-section of the front leg (14), the front surface of the front leg (14) is designed as an arched arc facing the front of the body (2). 4. The stroller according to claim 2, characterized in that, in the cross-section of the front leg (14), the front surface of the front leg (14) is designed as an arched arc facing the front of the body (2).