Disclosure of Invention
The invention provides a child handcart with a front handrail capable of being interlocked and folded, which solves the problem of low folding efficiency of the existing handcart.
The front handrail linked folding child handcart comprises a push rod, a front foot rod and a rear foot rod which are connected through a rotary joint, and is characterized in that the rotary joint comprises a first rotary element which is coaxially arranged and fixedly connected with the push rod, a second rotary element which is fixedly connected with the front foot rod and a third rotary element which is used as a front handrail mounting seat;
The linkage mechanisms are respectively arranged between the first rotating element and the third rotating element and between the second rotating element and the third rotating element, and each linkage mechanism comprises an arc groove which is respectively arranged on the two rotating elements and takes the rotation axis as the center of a circle and a linkage pin which stretches into the arc groove and can slide;
in the unfolded state of the frame, the linkage pin is positioned at the corresponding end part of the arc groove to limit the rotation of the third rotating element, and the first rotating element drives the third rotating element to rotate through the linkage mechanism in the folding process of the push rod to the front foot rod.
The third rotating element is positioned on the inner side of the rotating joint.
The first rotating element is arranged between the second rotating element and the third rotating element, the outer side of the rotating joint is provided with a decoration element fixedly connected with the push rod, and the second rotating element is clamped between the first rotating element and the decoration element.
The two circular arc grooves are arranged on the third rotating element, and the two linkage pins are arranged on the first rotating element and the second rotating element.
The first linear hole and the second linear hole of the axle center are arranged in the rotary joint, a locking pin which is inserted into the first linear hole and the second linear Kong Zuzhi and is used for relatively rotating the first rotary element and the second rotary element is arranged on the second rotary element, and a second circular arc hole which is connected with the second linear hole by taking the rotary axle center as the center of a circle is arranged on the second rotary element.
The child handcart comprises a sliding block connected with the locking pin, a stay wire connected with the sliding block and used for pulling the locking pin to be separated from the second linear hole, and a first reset spring abutted against the sliding block and used for driving the locking pin to slide into the second linear hole, wherein a waist-shaped hole in sliding fit with the rotating shaft is arranged on the sliding block in the radial direction.
The outer side of the rotary joint is provided with a decoration element fixedly connected with the push rod, the second rotary element is clamped between the first rotary element and the decoration element, and the inner side surface of the decoration element is provided with a sliding groove for accommodating the sliding block and the first reset spring.
Plugs are arranged at two ends of the front handrail, a concave area matched with the plugs is arranged on the inner side surface of the third rotating element, and clamping grooves matched with the plugs are formed in the edges of the concave area.
The plug is provided with a lock hole, and the center of the concave area is provided with a locking block matched with the lock hole and a second reset spring abutting against the locking block.
The rear foot rod is hinged with the second rotating element, a seat rod and a linkage rod which are hinged are arranged between the front foot rod and the rear foot rod, the seat rod is rotationally connected with the front foot rod, and the linkage rod is rotationally connected with the rear foot rod.
According to the folding trolley, the third element is locked by the two linkage pins in the unfolding state of the trolley frame, and the first rotating element drives the third element to rotate in the folding process, so that the front armrests are driven to fold together in the folding process of the trolley frame, the front armrests do not need to be removed in advance, and the folding efficiency of the trolley is improved.
Detailed Description
As shown in fig. 1, a child cart includes two symmetrically arranged side brackets, each of which includes a push rod 1, a front foot bar 2 and a rear foot bar 3 connected by a rotary joint 10, the tops of the two push rods 1 are connected by a U-shaped handle bar 100, and an unlocking device 101 is provided in the middle of the push rod. The unlocking device mainly comprises an unlocking block and a pull wire, when the unlocking block is held and unlocked, the pull wire can pull the locking pin in the rotary joint 10 to be separated from the locking position, so that the purpose of unlocking is achieved. The unlocking device may adopt the existing structure disclosed in patent documents such as CN204871148U, CN204488877U, CN206344864U, and the like, and will not be described in detail herein. A sunshade rod 6 is also arranged between the two push rods 1.
As shown in fig. 1, in the unfolded state of the frame, the front foot bar 2 and the push bar 1 are on the same straight line, and when the frame is folded, the push bar 1 needs to be turned 180 degrees to be in parallel contact with the front foot bar 2. The bottoms of the two front foot bars 2 are slightly bent inwards and are connected through the pedals 200, and two front wheels are arranged below the pedals 200. The two rear foot rods 3 are arranged in parallel, the bottoms of the two rear foot rods are provided with rear wheels, the two rear wheels share a wheel shaft, and a brake mechanism is arranged on the wheel shaft.
As shown in fig. 5 and 6, the rotary joint 10 includes a first rotary element 11, a second rotary element 12 and a third rotary element 13 which are coaxially connected, and the main body parts of the three rotary elements are all in a disc shape, so that the rotary elements can be closely attached to each other by adopting a disc structure, the volume of the rotary joint 10 can be reduced, and the rotary joint 10 can be cylindrical in shape, and the volume and the shape of the rotary joint remain unchanged when the rotary elements relatively rotate.
The third revolute joint 13 is used for fixedly mounting the front armrest 5, and is located on the inner side of the revolute joint 10, the second revolute joint 12 is located on the outer side, and the first revolute element 11 is located between the second revolute element 12 and the third revolute element 13. The positions of the three rotating elements can be arbitrary in theory, but since the front armrest is disposed across the two side brackets, if the third rotating element 13 is located at another position, the front armrest 5 will interfere with the push rod 1 and the front foot bar 2 when folded, so that the push rod 1 and the front foot bar 2 cannot be completely attached when folded, and maintain a parallel state.
In order to conceal the mechanical structure in the joint and to keep the second rotating element 12 stable during rotation, a decorative element 14 is provided on the outside of the rotating joint 1, the second rotating element 12 being sandwiched between the first rotating element 11 and the decorative element 14. As shown in fig. 7 and 8, a locking pin 113 passing through the second rotating element 12 is arranged between the decoration element 14 and the first rotating element 11, a linear hole 112 and a linear hole 122 with extension lines passing through the rotating shaft center are respectively arranged on the first rotating element 11 and the second rotating element 12, a circular arc hole 123 connected with the linear hole 122 is arranged on the second rotating element 12, when the locking pin 113 is positioned at the linear hole, the first rotating element 11 and the second rotating element 12 are locked and cannot rotate relatively, and when the locking pin 113 is separated from the linear hole 122 and slides into the circular arc hole 123, the first rotating element 11 and the second rotating element 12 are unlocked and can rotate relatively.
As shown in fig. 8, in order to provide guidance for the sliding of the locking pin and prevent the locking, the locking pin 113 is connected to the pull wire 144 through the slider 141, the inner side surface of the decoration element 14 is provided with a slide groove 143 engaged with the slider 141, both the slide groove 143 and the slider 141 pass through the rotation axis, and the slider 141 is provided with a waist-shaped hole 142 slidingly engaged with the connection axis. In addition, a return spring 145 that abuts the slider 141 is provided in the slide groove 143, and when the slider 141 is pulled by the wire, the return spring 145 is compressed, so that the lock pin 113 is disengaged from the linear hole 122 and enters the circular arc hole 123. When the locking pin 113 rotates to the engagement of the circular arc hole 123 and the linear hole 122, the locking pin 113 automatically enters the linear hole 122 due to the resilience of the return spring 145, thereby achieving locking.
In another embodiment of the invention, the ornamental element 14 is fixedly connected to the forefoot lever 2, the first rotating element 11 being clamped between the second rotating element and the ornamental element, the runner being provided on the first rotating element, but the design makes the first rotating element thicker, increasing the volume of the revolute joint.
The above is only one embodiment for locking the first rotating element and the second rotating element, and the rotating joint of the present invention may also be locked by using a ratchet wheel as disclosed in CN 206664663U.
As shown in fig. 7 and 8, the decorative element 14 and the first rotary element 11 are symmetrically arranged, and the tail parts of the decorative element and the first rotary element are assembled to form a connecting pipe 110 connected with the push rod 1. Likewise, the second rotary element 12 has a rear portion with a connecting tube 120 connected to the front foot bar 2 and a projection 121 hinged to the connecting tube 15, the connecting tube 15 being fixedly connected to the rear foot bar 3. The connecting pipes 110, 120 and 15 of the embodiment adopt a two-flap structure, and respectively clamp the post push rod 1, the front foot rod 2 and the rear foot rod 3 in the assembly process, and are fixedly connected by rivets, so that the assembly is convenient.
As shown in fig. 7, the side surface of the third rotating element 13 facing the first rotating element 11 is provided with an arc groove 134 and an arc groove 135 which take the rotation axis as the center, the second rotating element 12 and the first rotating element are respectively provided with a linkage pin 114 and a linkage pin 124 which are in sliding fit with the arc groove 134 and the smooth groove 135, the corresponding first rotating element 11 is provided with an arc hole 111 which avoids the linkage pin 124, and the arc groove and the linkage pin form a linkage mechanism between the two rotating elements. As shown in fig. 9, in the frame-unfolded state, the interlocking pin 114 and the interlocking pin 124 are located at the tips of the circular arc groove 134 and the circular arc groove 135, so that the third rotary element 13 is prevented from rotating relative to other rotary members.
The arrangement of the circular arc slot and the interlocking pin on the two interlocking rotating elements in this embodiment may be interchanged, for example, the circular arc slot 134 and the circular arc slot 135 may be arranged on the first rotating element and the second rotating element, and the interlocking pin 114 and the interlocking pin 124 may be arranged on the third rotating element. However, when the positions of the interlocking pin and the circular arc groove are interchanged, the position of the interlocking pin for locking the third rotating element also changes.
As shown in fig. 5 and 6, the front armrest 5 is provided with a plug 51 at both ends, a recess 54 is provided in the middle of the end of the plug 51, a lock hole 52 is provided in the middle of the recess, and a flange 53 is provided at the edge of the plug. The inner side of the third rotating element 13 is provided with a concave area 131 matched with the plug 51, the plug is flush with the surface of the third rotating element after installation, the edge of the concave area 131 is provided with a clamping groove matched with the folded edge 53, the middle of the concave area 131 is provided with a protrusion 132 matched with the concave 54 on the plug 51, and the protrusion 132 is provided with a locking block 161 with rebound ability against a return spring 162.
When the front armrest is installed, the plugs 51 at the two ends of the front armrest 5 are inserted into the clamping grooves on the concave areas 131, and the locking blocks 161 are matched with the locking holes 52 to lock the front armrest. When the lock block 161 is pressed during the disassembly, the return spring 162 is compressed, the lock block 161 is withdrawn from the lock hole 52, and the plug 51 can be withdrawn from the card slot. In order to prevent the locking block 161 from being ejected by the return spring 162, the mounting hole matched with the locking block 161 is formed in the boss 132, supporting legs with barbs are arranged on the back surface of the locking block 161, the two supporting legs are elastic and abut against the edge of the mounting hole, and the barbs can be prevented from being ejected by the return spring 162.
As shown in fig. 1, the child cart of this embodiment further includes a seat bar 4, the front end of the seat bar 4 is rotatably connected with the front foot bar 2, the rear end is rotatably connected with the rear foot bar 3 through a linkage bar 7, and the linkage bar 7 and the seat bar 4 are substantially in the same horizontal plane and are disposed between the rear foot bar 3 and the seat bar 4. The seat post 4 is mainly used for forming a seat for supporting a child sitting thereon, and is provided at its front end with an angle-adjustable leg rest 41. The seat bar 4 can also be used for carrying sleeping boxes, and is arranged according to different requirements. The purpose of the linkage rod 7 is mainly to fold the rear foot rod 3, and the rear foot rod 3 can be driven to approach the front foot rod when the seat rod 4 is turned over.
The mode of linkage folding the rear foot bar 3 is various, and the child handcart disclosed in CN206265119U drives the rear foot bar 3 to approach the front foot bar 2 through three connecting rods. In another embodiment, four rotating elements are arranged in the rotating joint, wherein three rotating elements are the same, the added rotating elements are fixedly connected with the rear foot rod, the rotating elements are provided with linear holes and circular arc holes matched with locking pins, the locking and unlocking modes are the same, and synchronous folding can be realized through the linkage rod after unlocking.
As shown in fig. 10 and 11, a cross bar 8 is disposed between the two seat bars 4, the cross bar 8 includes a hollow connecting tube 89, locking bars 85 are disposed at two ends of the connecting tube 89, a return spring 84 abutting against the two locking bars 85 is disposed between the two locking bars 85, and locking holes 71 matching with the locking bars 85 are disposed on the corresponding interlocking bars 7.
As shown in fig. 11, the connecting tube 89 is externally sleeved with two pairs of meshed axial sliding sleeves 82 and circumferential sliding sleeves 81, wherein the axial sliding sleeves 82 can axially move along the connecting tube 89, and the circumferential sliding sleeves 81 can circumferentially rotate relative to the connecting tube 89. The axial sliding sleeve 82 and the circumferential sliding sleeve 81 are coaxially arranged, two opposite ends of the axial sliding sleeve 82 and the circumferential sliding sleeve 81 are mutually meshed, the mutually meshed tooth edges 811 and 821 are obliquely arranged, each axial sliding sleeve 82 is connected with the corresponding locking rod 85 through a pin, and the connecting pipe 89 is provided with a waist-shaped hole 891 for the pin to pass through in the axial direction. The outer surface of the circumferential sliding block 81 is provided with a limiting block 810, and the two circumferential sliding sleeves 81 are sleeved with an external holding tube 80 through the limiting block 810, and when the locking is performed, the holding tube 80 is gripped to rotate, so that the two circumferential sliding sleeves 81 can be driven to synchronously rotate.
As shown in fig. 12, a secondary locking mechanism is further disposed on one side of the holding tube 80, the secondary locking mechanism includes an unlocking sliding sleeve 86 engaged with the holding tube 80, one end of the unlocking sliding sleeve 86, which is away from the holding tube 80, abuts against a return spring 87, the other end is provided with a rotation stopping block 861 extending into the circumferential sliding sleeve 81, and the inner surface of the corresponding circumferential sliding sleeve 81 is provided with a rotation stopping groove 88 matched with the rotation stopping block 861. The rotation stop grooves 88 and the rotation stop blocks 861 are circumferentially arranged in any number. The area of the connection pipe 89 not surrounded by the grip pipe 80 is provided with a protection pipe 83, the protection pipe 83 surrounds the return spring 87 and the unlocking slide sleeve 86, and a dial block 862 penetrating through the protection pipe 83 is provided on the unlocking slide sleeve 86.
When unlocking, the thumb pushes the poking block 862, the return spring 87 is compressed, and the rotation stopping block 861 exits the rotation stopping groove 88, so that the rotation of the circumferential sliding sleeve 81 is not limited any more. At this time, the holding tube 80 is gripped and rotated by a single hand, the holding tube 80 drives the two circumferential sliding sleeves 81 to rotate, then the axial sliding sleeves 82 are pushed to move in opposite directions, the locking rod 85 is driven to move in opposite directions, the locking end of the locking rod 85 is withdrawn from the locking hole 71, and the reset spring 84 is compressed to realize unlocking.
As shown in fig. 2 to 4, the working principle of the child stroller of the present invention is as follows:
When the first folding step is performed, the unlocking block on the unlocking device 101 is pressed, the unlocking block pulls the pull wire 145, the pull wire 145 pulls the sliding block 141 and the locking pin 113, the locking pin 113 withdraws from the linear hole 122 and enters the circular arc hole 123, the first rotating element 11 can rotate relative to the second rotating element 12, in the unfolded state, the handle tube 1 and the front foot rod 2 are positioned on the same straight line, and because the connecting tube 110 and the connecting tube 120 are eccentrically arranged, the connecting line of the handle tube 1 and the front foot tube 2 does not pass through the rotation center, and after the connecting line is folded for 180 degrees, the handle tube 1 and the front foot tube 2 can keep a parallel and leaning state.
In the frame-unfolded state, as shown in fig. 9, the interlocking pin 114 and the interlocking pin 124 are located at the top ends, i.e., opposite ends, of the circular arc grooves 134 and 135, respectively, to restrict the rotation of the third rotating element 13, and when the handlebar tube 1 is rotated toward the front foot bar 2, the interlocking pin 114 moves along the circular arc grooves 134 until it reaches the bottommost end, and the third rotating element 3 remains stationary. When the handle tube 1 continues to rotate, the interlocking pin 114 drives the third rotating element 13 to rotate together, and the interlocking pin 124 slides along the circular arc groove 135 until the handle tube 1 is folded 180 °. Because the plugs at both ends of the front armrest 5 are fixed to the third rotating member 13, the front armrest 5 is driven to rotate together during the folding of the handlebar tube 1.
As shown in fig. 3, the handle tube 1 is folded 180 ° to be parallel to the front foot tube 2. Then, a second folding step is performed, the thumb is held on the holding tube 80 to push the pulling block 862, so that the pulling block 862 moves leftwards, the return spring 87 is compressed, the rotation stop block 861 is withdrawn from the rotation stop groove, at this time, the holding tube 80 is rotated, the locking rod 85 is withdrawn from the locking hole 71, the cross rod 8 is lifted upwards, the seat rod 4 is rotated around the hinge point with the linkage rod 7, and the rear foot rod 3 is rotated close to the front foot rod 2 around the hinge point with the second rotating element 12 due to the gravity until the two remain parallel.
As shown in fig. 4, in the folded state, the handle tube 1, the front foot tube 2 and the rear foot tube 3 are kept in parallel and are abutted, and the whole vehicle body is small in thickness and convenient to carry and transport.