WO2007053018A1

WO2007053018A1 - Brake device, in particular for a buggy or pushchair

Info

Publication number: WO2007053018A1
Application number: PCT/NL2006/050270
Authority: WO
Inventors: Aernout Mattys Dijkstra
Original assignee: Royalty Bugaboo GmbH
Current assignee: Royalty Bugaboo GmbH
Priority date: 2005-11-01
Filing date: 2006-10-30
Publication date: 2007-05-10
Anticipated expiration: 2008-05-01
Also published as: NL1030331C2

Abstract

The invention relates to a brake device (100), in particular for a buggy or pushchair, wherein the brake device comprises: a braked left and right fixed wheel (9, 11); a cross bar (7) between said braked wheels (9, 11); a divided brake shaft with a left and right brake rod (119); an operating mechanism which is provided between the right and left brake rods (119) and is attached to the cross bar (7) for movement of the brake rods (119), in the longitudinal direction of the cross bar (7), from a release state releasing the braked wheels to a braking state wherein the distal (119d) end of each respective brake rod engages the respective braked wheel (9, 11). The braked wheels (9, 11) are swivellable with respect to the longitudinal axis of the cross bar (7). The right and left brake rods (119) have a proximal portion (119a) extending parallel to the longitudinal axis of the cross bar (7).

Description

Brake device, in particular for a buggy or pushchair

The present invention relates to a brake device, in particular for a buggy or pushchair, and also to a stroller, such as a buggy or pushchair, provided with a brake device of this type.

The present invention relates in this regard, in particular, to brake devices, in particular intended for a buggy or pushchair, comprising an operating mechanism which operates two wheels simultaneously, which wheels are referred to in the present document as braked wheels because there is also provided a brake which is able to engage said wheels. Even more specifically, the invention relates to a brake device of this type wherein the braked wheels are what are known as fixed wheels. The term "fixed wheels" refers in this connection to the fact that although the wheels are able to rotate for travelling, they are unable to steer or otherwise pivot about a substantially vertical axis. Fixed wheels are therefore wheels which have at all times an invariable direction of travel with respect to the stroller itself.

Baby strollers, such as buggies or pushchairs, with a centrally operating brake system acting on the rear wheels are known per se. Reference may be made to patent publications US 6,170,615, DE-201.16.190-U1 and EP-1.488.983-A2.

The brake device known from US 6,170,615 comprises a cross bar 22 carrying at its tips the braked rear wheels 21. The axles of the wheels coincide with the longitudinal axis of the cross bar. Centrally on the cross bar 22 there is provided the operating mechanism for the brake. Said operating mechanism consists of an oval disc 32 which can be operated for rotation using a handle 322. The brake device further comprises, in this case, a left brake rod 34 and a right brake rod 34. Said brake rods 34 are prestressed using a spring 312 in order to remain with their proximal ends against the circumferential edge of the oval disc 32. Rotating the oval disc 32 allows the brake rods 34 to be slid laterally outward in the axial direction, parallel to the longitudinal direction of the cross bar 22. The distal ends of the brake rods 34 will then in this case engage with a recess 212 of a circle of recesses 212 provided on each wheel hub in order subsequently to fix said wheel. As may be seen in Figure 3 of US 6,170,615, the brake rods are in this case attached below and parallel to the cross bar 22 and further to the right. Provided on the cross bar 22 are two brake rod guides 331. The braked wheels from US 6,170,615 are non-spring-mounted wheels, i.e. wheels of which the position with respect to the frame of the stroller is invariable. Said braked wheels are therefore not swivellable with respect to the longitudinal axis of the cross bar. The brake device from US 6,170,615 cannot be used in the case of braked wheels which are mounted so as to be swivellable with respect to the longitudinal axis of the cross bar 22. If the wheels 21 were pivotable with respect to the longitudinal axis of the cross bar 22, then the aligning of the brake rods 34 with the circle of recesses 212 on the wheel hubs would be lost, thus in the majority of cases preventing engagement of the distal end of the brake rods with a recess 212 from being produced. A further drawback of the brake device from US 6,170,615 is that when the distal end of one of the brake rods 34 is located precisely in between two recesses 212, the respective wheel has to be rotated before a braked state can be produced. If a braked state cannot be produced in the case of one wheel because the distal end 34 of the brake rod is situated at this location precisely in between two recesses 212, rotating of the oval disc 32 toward the braking state is also blocked, so the other brake rod is also unable to enter a braked state. This means that when the blocking wheel is rotated somewhat, the other wheel will soon also rotate with it, and this considerably complicates the bringing of the stroller into the braking state.

A further brake device is known from DE-201.16.190-U1 against which claim 1 of this PCT-application is delimitated. This is a brake device for a buggy with two braked rear wheels. Between the rear wheels there extends a mounting rod 31 carrying at its opposing tips a respective mounting seat 41. The mounting seats 41 extend from the mounting rod 31 in the transverse direction of said mounting rod 31. Mounted on each mounting seat is a rear wheel. Each rear wheel is provided on its hub with a circle of recesses 511. Each mounting seat 41 is further provided with a brake pin 441. Both the axis of rotation of the wheels and the brake pins are located, viewed in the transverse direction of the mounting rod 31, at a distance from said mounting rod and also parallel to said mounting rod. Provided in the centre of the mounting rod 31 is the operating mechanism for the brake. Said operating mechanism 16 is carried on separate, obliquely extending frame rods 15. On opposing sides of the operating mechanism 16, the mounting rod 31 carries a right and left brake rod 32 in the form of a tube which can be placed over the mounting rod 31. The brake mechanism consists of a brake pedal which is rotatable about a shaft carried by the oblique frame rods 15. Said brake pedal is provided with a wedge-shaped part 23 with a passage running therethrough for the mounting rod 31. The side faces 233 of the wedge- shaped part are in contact with the proximal ends of the tubular brake rods 32. On operation of the brake pedal, the tubular brake rods 32 will slide, as a result of the wedge shape in the axial direction of the mounting rod 31, in the direction of the wheels (distal direction). This movement in the distal direction utilises the brake pins 441 for movement, also in the distal direction, via a transmission mechanism accommodated in the mounting seats 41. Said transmission mechanism appears (the Applicant is not entirely sure) to consist substantially of a spring element 46. Said spring element consists of a helical spring portion 461 positioned on a pin 418, a resilient arm 46 and a portion 463 operating the brake pin 441. Outward movement of the tubular brake rod 32 appears to press the pin 43 (which is located in a fork at the end of the brake rod), approximately at the level of 462, against the resilient arm of the spring 46 in the direction of the wheel. The brake pin 441 is thus obviously pressed outward, in an unclearly described manner, into a recess 411 in the circle of recesses on the wheel hub. Should the brake pin 44 not be completely aligned with a recess 511, instead of the outward sliding of the brake pin 44, the spring 46 will be further loaded and there will be built up prestressing which causes the brake pin 44, once alignment has been produced, still to project into a recess 511. The distal end 43, 322-325 of the brake rod 32 does not in this case engage the wheel. This takes place by means of the brake pin 44 which is connected to the distal end of the brake rod 32 via a transmission mechanism, the spring 46. This brake device is complex in its structure and also comprises a large number of components which are fragile and prone to wear. In addition, as a result of the relatively large number of components, which are also relatively complex in their configuration, this structure is expensive. The spring 46, which forms the connection between the tubular brake rod and the brake pin, is also a fragile element. Moreover, owing to the fact that a spring of this type is prestressed, assembly of a system comprising a spring element 46 of this type is very awkward. Claim 1 of the PCT application as filed is delimitated against this DE-201.16.190-U1. Yet another brake device for a baby stroller is known from EP-1.488.983. This includes a cross bar 16 with the wheels 15 mounted at the tips thereof. The axles of the wheels 15 coincide with the longitudinal axis of the cross bar 16. Provided in the centre on the cross bar 16 is an operating mechanism 32 for a brake. Two brake rods 60 extend parallel to the cross bar and at some distance from the cross bar on opposing sides of the operating mechanism for the brake. The brake mechanism acts on the proximal ends of said brake rods and the distal ends 71 are able to engage with recesses 80 provided on the wheel hub. The brake rods 71 can be moved back and forth in this case using the brake mechanism. The brake mechanism adheres in this regard to the ballpoint or ballpen principle, i.e. the brake pedal 32 is operated from a release state and moved along an operating path in order to slide the brake rods outward. The brake pedal, just like the operating button of a ballpoint pen, will then return to the starting state. On subsequent operation, the operating member again being moved in the same direction over the same path, the brake rods are unlocked, so they are able to return. The stroller in EP-1.488.983 is a stroller, the rear wheels of which are fixed in position with respect to the remainder of the stroller. Said wheels are able merely to rotate about a horizontal axis for travel; they are unable to steer or move up and down with respect to the frame in the vertical direction. The wheels are also in this case immovable with respect to one another. In this regard, the brake device from EP- 1.488.983 has the same drawbacks as described hereinbefore in this respect with regard to US 6,170,615. A further drawback of the brake device according to EP- 1.488.983 is that it is impossible to tell from the position of the brake device, in particular the brake pedal, whether the stroller is in the braked state or in the unbraked state. Basically, this can only be detected from the distal ends 71 of the brake rods, although said ends are impossible or very difficult to see.

With baby strollers, including buggies and pushchairs, and also with wheelchairs, it is desirable for comfortable travel behaviour that the braked wheels are able to move with respect to the remainder of the stroller in the vertical direction. Insertion of a spring system thus allows suspension to be provided, and this damps vibrations resulting from an uneven road surface. It is in this regard particularly desired that a pair of wheels, positioned at a lateral distance from each other, are able to move independently of each other with respect to the frame. This considerably increases travelling comfort. However, wheels of this type are as a result usually braked independently of one another, i.e. each wheel has its own brake with its own operating means. Owing to considerations of ease of operation, it is desired that two wheels of this type, positioned at a mutual distance from each other and independently spring-mounted, are able to be applied to the brake in a single step and are also able to be removed from the brake in a single step. Known for this purpose are solutions consisting of a central operating mechanism connected to separate brakes via cables handled by said central operating mechanism. In practice, what are known as bowden cables are usually used for this purpose. Cables of this type have a number of drawbacks known per se. For example, they are highly sensitive to friction, and this complicates operation. They are sensitive to contamination, and this again causes friction to increase. Cables of this type are also subject to elongation, and this necessitates regular adjustment. A further drawback of cables of this type, in particular in baby strollers, is that they invite babies to pull on them and also that cables of this type can easily become caught.

The aim of the present invention is to provide a brake device, in particular for a pull/push stroller for the transporting of persons, which stroller is provided with wheels which are able to move independently of each other with respect to the stroller in the vertical direction thereof and can both be braked using a common operating mechanism. The brake device should also be simple in its construction, low-maintenance and function reliably, in particular over a relatively long period.

According to the invention, the aforementioned aims are achieved by providing a brake device for a main frame provided with wheels, in particular for a buggy or pushchair, wherein the brake device comprises:

• a braked left fixed wheel and a braked right fixed wheel;

• a cross bar extending between said braked wheels; the braked wheels being swivellable independently of each other with respect to the longitudinal axis of the cross bar;

• a right and left brake rod, the right and left brake rods each having a proximal end and a distal end;

• an operating mechanism which is provided between the right and left brake rods and is attached to the cross bar for displacement of the brake rods from a release state releasing the braked wheels to a braking state; the operating mechanism engaging the brake rods at the proximal end thereof; the distal end of the right brake rod being turned toward the right braked wheel and the distal end of the left brake rod being turned toward the left braked wheel; the right and left brake rods each having a proximal portion extending parallel to the longitudinal axis of the cross bar; and the right and left brake rod each being movable back and forth, in the direction of the longitudinal axis of the cross bar, between said release state and said braking state; characterized in that, in the braking state, the distal end of each respective brake rod engages the respective braked wheel. The braked wheels of said brake device are swivellable independently of each other with respect to the longitudinal axis of the cross bar and are thus, if the brake device forms part of a stroller, movable independently of each other with respect to the main frame of said stroller, for example for the purposes of suspension. However, the fact that the wheels are swivellable independently of each other with respect to the longitudinal axis of the cross bar can also be utilised, separately from the suspension means or in addition to the suspension means, in order to be able to be able to fold up a folding stroller even more compactly. As a result of the fact that the right and left brake rods each engage with their proximal end the operating mechanism and then with their distal end the respective wheel, the brake rod of the structure can be very simple. The brake rod forms the connection between the operating mechanism and the wheel. The brake rod can optionally even be made from a single piece of material. It will be clear that the brake rod can easily comprise at the distal end, within the scope of protection defined by the claims, a brake block, made for example from rubber, with which the wheel can be braked by frictional interlocking.

According to the invention, it is particularly advantageous if the longitudinal axis of at least a proximal portion of each brake rod coincides with the longitudinal axis of the cross bar. A compact integral unit consisting of the cross bar and brake rod can thus be produced. The brake rod can, for example, be integrated entirely or partially into the cross bar or the cross bar can extend through at least a portion of the brake rod.

According to the invention, it is also advantageous in this regard if the distal end of each brake rod is located, viewed in a direction perpendicular to the longitudinal axis of the cross bar, at a distance from said longitudinal axis and if each brake rod is pivotable with respect to said longitudinal axis in order to pivot in tandem with the swivelling of the respective wheel. There is thus provided in a highly simple and effective manner a brake device able to brake at all times two wheels, which are movable independently of each other in the vertical direction with respect to the frame, regardless of the position of said wheels with respect to the frame.

It is in this regard also advantageous if each braked wheel is provided with a distal guide for the distal end of the respective brake rod and if said distal guide has a fixed position with respect to the wheel axle of said respective braked wheel. A distal guide of this type ensures at all times that the distal end of the brake rod is able to find the suitable point of engagement, devised in advance by the Inventor, on the wheel. That is to say, the distal guide, which is fixed in position with respect to the braked wheel, will ensure at all times that the distal end of the brake rod arrives at the same location with respect to the wheel (unless the wheel is able to rotate of its own accord about its axis).

In order, during braking, to be able to produce mechanically blocking interlocking between the brake rods and wheels, it is in accordance with the invention advantageous if each wheel has a rim, said rims being provided on the mutually facing sides with a circular series of recesses, and if the distal end of each brake rod is located transversely to the circular series of recesses in the respective wheel and fits into each recess in such a way that, in the braking state, the distal end of said brake rod is able to protrude into one of the recesses of said series.

According to a further embodiment of the invention, it is advantageous if the brake device comprises for each brake rod a drawback spring, preferably a compression spring, which acts on said brake rod and is attached in such a way that when the brake rod is moved in the direction of the braking state, said spring is tensioned in order to counteract this movement. A spring of this type ensures that the brake rod, after release of the operating mechanism, returns reliably from the braking state to the release state and cannot, for example, become stuck. In order to counteract this becoming stuck with a high degree of certainty, it is in accordance with the invention also advantageous if said drawback spring is prestressed, in the release state, in an opposing direction to that of the sliding movement toward the braking state. The spring will thus at all times exert a force on the brake rod in the direction of the release state.

According to a further embodiment of the invention, it is advantageous if the operating mechanism comprises a right and a left thrust bearing which the proximal ends of the respective brake rods engage, and if the operating mechanism is configured in such a way that during operation of the operating mechanism in order to move the brake rods toward the braking state, each respective thrust bearing moves in the direction of the respective end of the cross bar. Reliable transmission of operating forces to the brake rods is possible using thrust bearings of this type.

It is in this regard particularly advantageous in accordance with the invention if the proximal end of each brake rod is movably accommodated in a bore formed in the respective thrust bearing and if there is provided for each brake rod a receiving spring, which receiving spring engages, on the one hand, the respective brake rod and, on the other hand, the respective thrust bearing in order to facilitate movement of the thrust bearing in the direction of the braking state when movement of the brake rod is impeded. As a result, if, during operation of the operating mechanism from the release state to the braking state, one of the brake rods is blocked, this does not lead to blocking of the operating mechanism and the other brake rod therefore continues to be operated as normal. That is to say, the bore in the thrust bearing allows the proximal end of the brake rod to be accommodated, so the thrust bearing can still be displaced in the direction of the respective wheel, whereas the brake rod itself can remain stationary. This can be useful, inter alia, if the hub of the wheel is provided with recesses with which the distal end of the brake rod has to engage and the recess and the distal end are not properly aligned. According to the invention, it is particularly advantageous if the receiving spring and the drawback spring are used jointly, if the receiving spring is prestressed in the release state and if, in the release state, the prestressing force of the receiving spring and the prestressing force of the drawback spring are substantially equal in magnitude and opposed in direction. Prestressing both springs ensures that both function reliably. Prestressing them with forces which are substantially equal but act in opposing directions allows the brake rods, in the release state, to remain neatly in place.

It will be clear that the operating mechanism required for a brake device according to the invention can be constructed in many different ways, including many different ways known from the prior art (see, for example, US 6,170,615, EP 1.488.983 and DE 201.16.190, to which reference has already been made). However, in accordance with the invention, it is advantageous, in the case of a brake device according to the invention, if the operating mechanism further comprises an operating cam which is provided in between the right and left thrust bearing and contacts both thrust bearings; if the pair of mutually contacting faces of the right thrust bearing and the operating cam and the pair of mutually contacting faces of the left thrust bearing and the operating cam each comprise a first contact face and a second contact face; if the first contact face of each pair of contact faces defines in each case for the second contact face a guide path having a course such that when the operating cam is moved with respect to the thrust bearings in a direction transverse to the longitudinal axis of the cross bar - in particular, is rotated about said longitudinal axis - in order to allow the first and second contact faces to slide along each other, the thrust bearings undergo displacement, defined by the guide path, in the direction of said longitudinal axis. It is in this regard particularly advantageous in accordance with the invention if the guide paths extend in the circumferential direction of the longitudinal axis of the cross bar and preferably have a constant radius with respect to the longitudinal axis of the cross bar. It is thus possible to rotate the operating cam about the longitudinal axis of the cross bar for operation.

According to a further embodiment of the invention, it is highly advantageous in this regard if the guide paths are mirror-symmetrical with respect to one another; if each guide path extends from a first point via a second point to a third point; if the second and third points are both located, viewed in the direction of the longitudinal axis of the cross bar, at a distance from the first point; if the third point is located, viewed in the direction of the longitudinal axis of the cross bar, between the first and second points; and if the first and second contact faces contact each other, in the release state, in the first point and, in the braking state, in the third point. There is thus produced in the brake mechanism a locking means with which the brake device can be locked in the braked state. When moving from the release state to the braking state, the second contact face will, as it were, rise from the first point, along the guide path, to the second point and from said second point - which is, as it were, a peak - fall back to the third point in order to remain in the braking state at this location. In order then to cancel the braking state, the second contact face will return in the opposite direction, along the first contact face, to the first point. For this purpose, the second contact face should first, as it were, rise from the third point to the, as it were, higher second point in order then to fall back from the, as it were, higher second point to this, as it were, lower first point, at which location the brake device is again in the release state. The second point of the guide path, which forms, as it were, a highest hurdle to be overcome, thus prevents the brake device both from being accidentally displaced from the release state to the braking state and, conversely, from being accidentally displaced from the braking state to the release state. It is in this regard advantageous in accordance with the invention if the first contact faces are provided on the operating cam and the second contact faces are provided on the thrust bearings.

With a view to simple operation, it is advantageous in accordance with the invention if the operating cam forms part of an operating pedal which is mounted such that it may be rotated about the longitudinal axis of the cross bar.

According to a further embodiment of the invention, it is particularly advantageous if each aforementioned wheel comprises a suspension means which counteracts upward swivelling of the wheel and if the suspension means of the right wheel and the suspension means of the left wheel function independently of each other. The suspension means of each wheel can in this case comprise a linear spring. A linear spring is in practice usually easier to replace than a torsion spring. However, a torsion spring could also be used for the suspension means within the scope of the claims of the present application. According to the invention, the linear spring will in particular be mounted in such a way that said spring is compressed during upward swivelling of the respective wheel. A spring subjected to compressive stress is less liable to break than a spring subjected to tensile stress. According to a further embodiment of the invention, each wheel is accommodated in a wheel fork, the wheel fork of the right wheel being fastened to the right end of the cross bar such that it may swivel and the wheel fork of the left wheel being fastened to the left end of the cross bar such that it may swivel.

According to one embodiment of the invention, it is also advantageous if the right and left brake rods are each substantially of one-piece construction. The term "one-piece" refers in this case to the fact that it is a component which can be assembled in one step in the integral unit of the brake device. As such, said component can consist of various parts fastened to one another, for example welded to one another. However, in the case of the brake device according to the invention, it is easily possible to construct the brake rods not only in one piece but even from a single piece of material such as, for example, a metal bar bent into a suitable shape. The present invention further relates to a pull/push stroller, which stroller is provided with a brake device according to the invention.

A pull/push stroller of this type according to the invention advantageously comprises a seat for the transporting of a person. In particular, it is advantageous if said seat is a seat for a person younger than 6 years old. A seat of this type may be not only a high chair but also a carrycot for a baby, wherein the baby substantially lies and does not sit.

According to a further embodiment of the invention, the stroller is a folding stroller. The present invention will be explained in more detail below with reference to an illustrative embodiment represented schematically in the drawings, in which:

Figure 1 is a schematic, perspective view of a buggy according to the invention, which is provided with a detachable seat;

Figure 2 is a view corresponding to Figure 1 , but wherein the detachable seat has been removed;

Figure 3 is a schematic, perspective view of a detachable seat for a buggy according to the invention; Figure 4 is a perspective view of the buggy according to Figures 1, 2 and 3 in the folded state; Figure 4a showing the folded buggy with the seat and Figure 4b showing the same folded buggy without the seat;

Figure 5 is a detailed, perspective, schematic view of the central portion of the main frame of the buggy according to Figures 1 to 4;

Figure 6 is a perspective view of a brake device according to the invention, which is a component of the buggy as shown in Figures 1 to 5;

Figure 7 is the same view as Figure 6, but in this case with half of the parts separated from one another;

Figure 8 is a detailed, perspective view of specific components of the brake device according to the invention in order to illustrate, in particular, the brake mechanism; and

Figure 9 is a detailed, perspective view of the operating member of the brake device shown in Figures 6 to 8. The concepts of "front" and "rear", as in front wheels and rear wheels, are used in the present application with reference, viewed in the longitudinal direction of the stroller/buggy, to one longitudinal end and with reference to the other longitudinal end. Which part is in use the front and which part the rear of the stroller/buggy will depend, inter alia, on the manner of use, i.e. whether the stroller/buggy is pushed or pulled. It is also the case that the firm Bugaboo sells buggies wherein the pull/push rod can be folded over with respect to the remainder of the frame - to take a concrete example, over approximately 90 to 120° - in order optionally to position said rod on one longitudinal end of the buggy or on the other longitudinal end of the buggy. The user can then either pull or push the buggy from one longitudinal end or pull or push the buggy from the other longitudinal end. This capacity of the pull/push rod to be folded over from one longitudinal end to the other longitudinal end is, inter alia, advantageous if there are provided at one longitudinal end swivelling wheels and at the other longitudinal end non-swivellable wheels which remain parallel to each other and may have wider tyres and a larger diameter than the swivelling wheels. As a result, depending on the conditions under which the buggy is used, the position of the pull/push rod may thus be adapted. If there is relatively little space in which to manoeuvre the buggy, such as is the case, for example, in a supermarket, then provision may be made to position the pull/push rod at the longitudinal end with the swivelling wheels. If the buggy is used on a relatively soft ground, for example a sandy ground, then it will usually be advantageous if the pull/push rod is positioned at the end with the fixed, non-swivelling wheels. It will be clear from the foregoing that the concepts of "front" and "rear" are, in the case of a stroller/buggy according to the invention (for example, in relation to the concepts of front wheels and rear wheels), relative concepts which distinguish between provision at one longitudinal end of the buggy and provision at the other longitudinal end of the buggy, although this does not mean that the scope of protection is restricted by the use of the concepts of "front" and "rear". It will also be clear that the same inherently applies to the concepts of "left" and "right".

Figures 1, 2, 3 and 4 show an illustrative embodiment of a buggy according to the invention in its entirety. This embodiment relates to a folding buggy, the folded state of which is shown in Figure 4. In this embodiment, the seat, which is illustrated separately in Figure 3, is also detachable. In Figures 1 and 4a, the seat is shown fastened in the main frame and Figures 2 and 4b show the main frame of the buggy without a seat being provided therein. In Figures 1 to 4, the buggy is denoted in its entirety by reference numeral 1. Said buggy 1 is constructed from a seat 5 and a main frame of rods and wheels wherein the seat 5 can be carried in a removable manner.

The main frame is constructed from:

- a pull/push handle 13 provided on pull/push rods 4, i.e. a left pull/push rod 4L and a right pull/push rod 4R;

- two rear wheel rods 3, i.e. a left rear wheel rod 3L and a right rear wheel rod 3R;

- two curved front wheel rods 2, i.e. a right front wheel rod 2R and a left front wheel rod 2L;

- two rear wheels 11, i.e. a right rear wheel 1 IR and a left rear wheel 1 IL; which rear wheels are provided at the lower ends of the rear wheel rods 3;

- two front wheels 9, both configured as spring-mounted swivelling wheels, preferably configured in accordance with NL 1.023.789/WO 2005/002882; the left front wheel is denoted by reference numeral 9L and the right front wheel by reference numeral 9R;

- a front cross bar system 6 provided between the lower ends of the front wheel rods 2; which front cross bar system provides, at least when the buggy is unfolded, a, viewed in the transverse direction T of the buggy, rigid connection between said lower ends of the front wheel rods in such a way that, viewed in said transverse direction T, the mutual distance between said lower ends of the front wheel rods 2 is invariable;

- a rear cross bar system 7 provided at the lower ends of the rear wheel rods 3 in order, viewed in the transverse direction T of the buggy, to produce a rigid connection of said lower ends of the rear wheel rods 3 in such a way that, viewed in the transverse direction T, the mutual distance between the lower ends of the rear wheel rods is fixed, at least when the buggy is unfolded; - a central frame part 14 which is shown in detail in Figure 5 and will be discussed at greater length hereinafter.

As will be clear from the foregoing, the letters L and R are added to the reference numerals in order to distinguish between a left and a right element which are otherwise identical to each other. This addition of the letters L and R having the same meaning will also be used with other elements to be discussed in greater detail. It will also occur that a reference numeral is used in the text of the description without the added letter L or R, whereas in the drawings this reference numeral is found only with the added letter L and/or R, or vice versa. It will, however, be clear that the respective element is the same in each case. If, for example, the text refers to the rear wheel 11, then it will be clear that the reference numeral 1 IR and/or 1 IL from the drawings is included.

With reference, in particular, to Figure 3, the seat 5 of the buggy according to the invention consists of a seat part 15, a back part 16 and two arms 17, i.e. a right arm 17R and a left arm 17L. The seat part 15 and the back part 16 are connected to each other so as to be able to hinge about a hinge axis 18. When the seat is removed from the main frame, as illustrated in Figure 3, the seat part 15 can be pivoted upward, in the direction of arrow 19, to a position approximately parallel to that of the back part. An, as it were, tightly folded state of the seat is thus obtained. As may be seen in Figure 4a, the seat can also produce this "tightly folded state" when the seat is fastened in the main frame. With reference, in particular, to Figures 1 , 2 and 4, it may be seen that the front wheel rods 2 and rear wheel rods 3 are fastened to the respective push rod 4 via a common sliding part 38. The sliding part 38 can be moved in the longitudinal direction of the push rod 4, along the push rod, between a low position corresponding to the unfolded state of the buggy - see Figure 2, wherein the sliding part is located relatively close to the lower end of the push rod 4 - and a high position corresponding to the folded state of the buggy - see Figure 4b, wherein the sliding part 18 is located further away from the lower end of the push rod 4 than when the buggy is unfolded. The rear wheel rods are fastened to the sliding part 38 via a hinging fastening 39 and the front wheel rods 2 are fastened to the sliding part 38 via hinges 40. In the case of the buggy shown in Figures 1 to 4, the front wheel rods 2 and rear wheel rods 3 become, as it were, parallel to the pull/push rod 4, when the buggy is folded (see Fig. 4), by moving the sliding part 38 upward along the pull/push rod in the direction of the push handle 13. In order to prevent accidental folding of the buggy there is provided on each pull/push rod 4 a lock which, in the unfolded state, locks the sliding parts 38 with respect to the pull/push rods 4. Said lock can consist of a respective pin which can be retracted into the respective pull/push rods. Said pins can be operated via sliding knobs 41 which are provided on each pull/push rod and are able to retract said pins, via a transmission means, counter to the action of a drawback spring. The pull/push rods 4 are configured so as to telescope (at the sliding knobs 41). As may be seen in Fig. 4, a more compact overall structure can thus be achieved in the folded state. This telescoping also allows the height of the handle 13 to be adapted as the user desires.

The buggy illustrated in Figures 1 to 4 is also provided with a central frame part 14 which is shown in detail in Figure 5. Said central frame part comprises a central cross part 8 fastened between the lower ends of the pull/push rods 4. Said central cross part 8 comprises a base 36 and a central cross bar 37 joined together in a non-rotatable manner. From the base 36 there extend in the forward direction F a left front base arm 2OL and a right front base arm 2OR. The front base arms 20 are each fastened, at one end, to the base 36 so as to hinge about a hinge axis 21 and, at the other end, to a respective front wheel rod 2 so as to hinge about a hinge axis 22. The hinging fastening of the front base arms 20 to the respective front wheel rods 2 is an immovable fastening, i.e. the location of the hinge axis 22 with respect to the respective front wheel rod is, viewed in the longitudinal direction of the front wheel rod, invariable. As a result of the fact that the hinge axes 21 extend neither parallel to the transverse direction T of the buggy nor transverse to the longitudinal direction L of the buggy but rather obliquely with respect to both the longitudinal direction L and the transverse direction T of the buggy, the free ends 23 of the front base arms 20, if they pivot upward in the direction indicated by arrow 24 in Figure 5, will, viewed in the transverse direction T of the buggy, move closer to each other. The result of this is that the lower ends of the front wheel rods 2, and thus the front wheels 9, move toward each other. Owing to the fact that when the buggy is folded, the sliding part 38 slides upward along the pull/push rod, the front wheel rods 2 will, when the buggy is folded, fold the front base arms 20 upward in the direction of arrow 24, as a result of which the front wheels 9 will move toward each other when the buggy is folded. When the buggy is unfolded, precisely the opposite will occur. On the rear side B, the base part 14 carries two rear base arms 25, i.e. a right rear base arm 25R and a left rear base arm 25L. The right rear base arm 25R and the left rear base arm 25L form part of a one-piece U-shaped plastics material part. It will, however, be clear that the rear base arms 25R and 25L can also be two separate components and also that they do not have to be made from plasties material. The rear base arms 25 are fastened to the base 36 so as to hinge about a hinge axis 26. At their other end, the free end 27, the rear base arms 25 are fastened to the rear cross bar system 7. This is also a hinging fastening, the free ends 27 of the rear base arms 25 being rotatable about the rear cross bar system 7. When the buggy is folded up, the sliding part 38 is slid upward along the pull/push rod and thus pulls the rear wheel rods 3 upward. The upward pulling of the rear wheel rods 3 causes the rear cross bar system 7 to be pulled upward, so the rear base arms 25 will pivot upward in the direction of arrow 28.

That which has been described hereinbefore with reference to Figures 1 to 5 concerns a general description of an illustrative embodiment of a buggy according to the invention. The subject-matter of the invention of the present application will be considered hereinafter more specifically. It will be clear to a person skilled in the art that said subject-matter of the invention is more broadly applicable than only with the embodiment, described hereinbefore in relation to the figures. The brake device according to the invention will be discussed hereinafter in greater detail with reference to Figures 6, 7, 8 and 9. In Figure 7, the right half of the cross bar 7 is not shown in order to make visible that which is accommodated therein. In Figure 8, basically only half of the brake device is shown, the cross bar and the wheels having been omitted in their entirety. Said brake device is constructed around the rear cross bar 7. In the illustrated embodiment, said cross bar 7 is hollow, so various components of the brake device can be accommodated therein. The cross bar 7 carries at both tips a braked wheel 11 known as a fixed wheel. The cross bar 7 ensures that the mutual distance between the wheels 11 , which in this case are the rear wheels, is more or less rigidly fixed. The wheels 11 are carried, in a manner conventional per se, in forks 115 and are each suspended in the forks 115 so as to be able to rotate about a wheel axle 113. Each fork is fastened to the cross bar 7 so as to be able to swivel about the cross bar 7 by means of a hinge 133. In each hinge 133 there is also provided a foot 134 for the rear wheel rods. Between said foot 134 and a protruding lip 135 on the fork 115 there is provided a respective spring 12. Resilient suspension of the wheel 11 from the cross bar 7 is thus produced. It will be clear in this regard that the right wheel 1 IR and the left wheel 1 IL can be spring-mounted independently of each other. When they are spring-mounted, the wheels 11 will swivel about the longitudinal axis 101 of the cross bar 7 (see double-headed arrow V in Figure 6) over an angle. With reference, in particular, to Figures 7 and 8, it may be seen that at the centre of the cross bar there is provided an operating mechanism 102 comprising, inter alia, a brake pedal 118 shown separately and in perspective in Figure 9.

Provided on opposing sides of the operating mechanism 102 is a brake rod 119. As may be seen in Figures 7 and 8, each brake rod 119 consists in this case of a, viewed from the operating mechanism, proximal portion 119a and a distal portion 119c extending parallel thereto. The proximal portion 119a and distal portion 119c are joined together by a connection portion 119b. The brake rod 119 as a whole is, in each case, formed from a single piece of metal wire wherein two 90° angles are folded at suitable locations. It will be noted that the connection portion 119b can also extend, instead of perpendicularly to the longitudinal axis 101 of the cross bar 7, obliquely with respect to said longitudinal axis 101 or can extend along a curved path.

The brake rod 119 also has a distal end 119d and a proximal end 119e. The distal end 119d is guided in a distal guide 115c. The distal guide 115c consists substantially of a bore through one of the legs of the fork 115. Via the distal guide 115c, the distal portion 119c of the brake rod is at all times aligned with the circular series of recesses 120 provided on the inside of the wheel rim. Moving the brake rods 119 back and forth in the direction of arrows P (P = proximal direction) and D (D = distal direction) allows the brake rods 119 to be moved between a braking state and a release state. In the braking state, the distal ends 119d of the brake rods 119 engage with a recess 120 in the rim of each respective wheel. In said braking state, both brake rods are slid outward in the distal direction D - distally with respect to the operating mechanism 118. In the release state, both brake rods 119 are slid inward in the proximal direction P - proximally with respect to the operating mechanism 118 - in the direction of the operating mechanism 118. The operating mechanism 118 allows the brake rods 119 to be moved back and forth in the direction of arrows P and D.

The fact that the longitudinal axis of the proximal portion 119a of the brake rods in each case substantially coincides with the longitudinal axis 101 of the cross bar 7, at least with the swivel axis with respect to which the wheel forks 115 are swivellable, means that when one wheel 11 is swivelled, with respect to the remainder of the frame or optionally with respect to the other wheel 11, the distance between the distal end 119d of the brake rod and the longitudinal axis of the proximal portion 119a of this same brake rod remains invariable. The brake rod is thus able freely to pivot in tandem with the swivelling of the wheel without impeding the swivelling of the wheel or disturbing the functioning of the brake device.

In order to assist the returning of the brake rods from the braking state to the release state there is provided for each brake rod 119 a drawback spring 127. Between the drawback spring 127 and the brake rod 119 there is provided in each case a further sliding part 126 having, on one edge, a pin for fastening the spring 127 and, on the other edge, a recess wherein the brake rod 119 can be accommodated on transition from the proximal portion 119a to the connection portion 119b. The side of the spring 127 that is remote from the sliding part 126 is held in place by a pin 114. The spring 127 thus engages, on the one hand, the pin 114 and, on the other hand, the sliding part 126. The spring 127 is preferably prestressed at all times, even in the release state.

With reference, in particular, to the left-hand portion of Figure 8, it may be seen that the proximal end 119e of each brake rod 119 is, in each case, received in a bore 125. Said bore 125 is formed in a thrust bearing 121. It may also be seen that there is provided a receiving spring 124 which engages, on the one hand, at 123 the proximal portion 119a of the brake rod and, on the other hand, at 136 the thrust bearing 121. If the proximal end 119e of the brake rod is pressed into the bore 125, there builds up in the spring 124 a tension which tends to push the brake rod back out of the bore 125.

On operation of the operating mechanism 102, each respective thrust bearing 121 will be pressed, in a manner to be described hereinafter, toward the closest respective wheel. Via the spring 124, the brake rod 119 is therefore also pressed toward said respective wheel. Should the movement of the brake rod 119 in said distal direction be impeded, then the outward sliding of the thrust bearing 121 in the distal direction will be able to continue under the compression of the spring 124 and entering of the proximal end 119e further into the bore 125. The manner in which the thrust bearings 121 are moved using the brake pedal 118 will be described hereinafter. The brake pedal 118 is rotatable about the cross bar 7. Provided on the underside of the brake pedal 118 is an operating cam 122 extending around the outside of the cross bar 7. The operating cam 122 has, on opposing sides, a first contact face 122b extending in the circumferential direction of the cross bar 7. Said contact faces 122b are, in each case, turned toward the respective wheel. Each thrust part 121 is also provided with an upright cam 138 having, on the side thereof that faces the operating cam 122, what is known as a second contact face 121b. The first contact face 122b extends not only in the direction of the circumference of the cross bar 7/the longitudinal axis 101 thereof, but also in the direction of the length of said cross bar 7/longitudinal axis 101. As a result, when the cam 122 is rotated about the longitudinal axis 101 using the foot pedal 118, the upright cam 138 will follow a path, defined by the course of the first contact face 122b, along the longitudinal axis 101. Looking more specifically at the first contact face 122b, a first point 130 and a second point 131 may be seen at this location. The point 130 forms, as it were, the bottom and the point 131, as it were, the top of a rising section of the guide path 122b. In Figure 8, the brake pedal 118 and the remainder of the brake device are shown in the release state. If the brake pedal 118 is then rotated in the direction of arrow W, then the second contact face 121b of the upright cam 138b will follow the rising section of the guide path 122b from the bottom 130 to the top 131. The thrust bearing 121, shown on the left-hand side in Figure 8, is thus then moved to the left (in the distal direction D). As soon as the second contact face 121b has reached the top 131, also referred to as the second point, said second contact face arrives at a cup-shaped section 139 of the first contact face 122b. Said cup-shaped section 139 contains what is known as the third point, which is denoted by reference numeral 132. Said third point 132 will, in particular, be the lowest point of the cup-shaped section 139, although it can also be a different point of said cup-shaped section, for example if the cam 138 is provided with a spacer which prevents the lowest point of the cup-shaped section from being reached. The second contact face 121b will come to rest at said lowest point 132. The springs 127 and 124, in particular the spring 127, will ensure in this regard that the second thrust bearing 121, or at least the upright cam 138 thereof, will remain in said cup- shaped section 139 of the first contact face. The brake pedal 118 is thus, as it were, locked in the breaking state. As will be clear, said lock is simple for the operator to cancel by rotating the brake pedal 118, using his foot or using his hand, in the opposite direction to that indicated by arrow W. The first contact face 121b of the upright cam 138 will then, as it were, climb upward from the bottom 132 to the top 131 in order then to fall back downward to the bottom 130.

Claims

1. Brake device (100) for a main frame provided with wheels (9, 11), in particular for a 5 buggy or pushchair, wherein the brake device (100) comprises:

• a braked left fixed wheel (HL) and a braked right fixed wheel (1 IR);

• a cross bar (7) extending between said braked wheels (11); the braked wheels (11) being swivellable independently of each other with respect to the longitudinal axis (101) of the cross bar (7);

10 • a right and left brake rod (119), the right and left brake rods (119) each having a proximal end (119e) and a distal end (119d);

• an operating mechanism (102) which is provided between the right and left brake rods (119) and is attached to the cross bar (7) for displacement of the brake rods (119) from a release state releasing the braked wheels (11) to a braking state;

15 the operating mechanism (102) engaging the brake rods (119) at the proximal end (119e) thereof; the distal end (119d) of the right brake rod (119) being turned toward the right braked wheel (HR) and the distal end (119d) of the left brake rod (119) being turned toward the left braked wheel (HL);

20 the right and left brake rods (119) each having a proximal portion (119a) extending parallel to the longitudinal axis (101) of the cross bar (7); and the right and left brake rod (119) each being movable back and forth, in the direction of the longitudinal axis (101) of the cross bar (7), between said release state and said braking state, characterized in that, in the braking state, the distal end (119d) of each respective brake rod

25 engages the respective braked wheel (11).

2. 2. Brake device (100) according to Claim 1, wherein the longitudinal axis of at least the proximal portion (119a) of each brake rod (119) coincides with the longitudinal axis (101) of the cross bar (7).

30

3. Brake device (100) according to Claim 2, wherein the distal end (119d) of each brake rod (119) is located, viewed in a direction perpendicular to the longitudinal axis (101) of the cross bar (7), at a distance from said longitudinal axis (101) of the cross bar (7) and wherein each brake rod (119) is pivo table with respect to said longitudinal axis (101) of the cross bar (7) in order to pivot in tandem with the swivelling of the respective braked wheel (11).

4. Brake device (100) according to Claim 3, wherein each braked wheel (11) is provided with a distal guide (115c) for the distal end (119d) of the respective brake rod (119) and wherein said distal guide (115c) has a fixed position with respect to the wheel axle (113) of said respective braked wheel (11).

5. Brake device according to Claim 3 or 4, wherein each brake rod (119) has a distal portion (119c) and an intermediate portion (119b) connecting the distal portion (119c) to the proximal portion (119a) and wherein the distal portion (119c) and the proximal portion (119a) are parallel to each other.

6. Brake device (100) according to one of the preceding claims, wherein each braked wheel (11) has a rim (103), said rims (103) being provided on the mutually facing sides with a circular series of recesses (120), the distal end (119d) of each brake rod (119) being located transversely to the circular series of recesses (120) in the respective braked wheel (11) and fitting into each recess (120) in such a way that, in the braking state, the distal end (119d) of said brake rod (119) is able to protrude into one of the recesses (120) of said series.

7. Brake device (100) according to one of the preceding claims, wherein the brake device (100) comprises for each brake rod (119) a drawback spring (127), preferably a compression spring, which acts on said brake rod (119) and is arranged in such a way that when the brake rod (119) is moved in the direction (D) of the braking state, said spring is tensioned in order to counteract this movement.

8. Brake device according to Claim 7, wherein said drawback spring (127) is prestressed, in the release state, in a direction (P) opposing to that of the sliding movement toward the braking state.

9. Brake device (100) according to one of the preceding claims, wherein the operating mechanism (102) comprises a right and a left thrust bearing (121) which the proximal portions (119a) of the respective brake rods (119) engage; and wherein the operating mechanism (102) is configured in such a way that during operation of the operating mechanism (102) in order to move the brake rods (119) toward the braking state, each respective thrust bearing (121) moves in the direction (D) of the respective end of the cross bar (7).

10. Brake device (100) according to Claim 9, wherein the proximal end (119e) of each brake rod (119) is movably accommodated in a bore (125) formed in the respective thrust bearing (121) and wherein there is provided for each brake rod (119) a receiving spring (124) which engages, on the one hand, the respective brake rod (119) and, on the other hand, the respective thrust bearing (121) in order to facilitate movement of the thrust bearing (121) in the direction (D) of the braking state when movement of the brake rod (119) is impeded.

11. Brake device (100) according to Claim 10 in combination with Claim 8, wherein the receiving spring (124) is prestressed in the release state and wherein, in the release state, the prestressing force of the receiving spring (124) and the prestressing force of the drawback spring (127) are substantially equal in magnitude and opposed in direction.

12. Brake device (100) according to one of Claims 9 to 11, wherein the operating mechanism (101) further comprises an operating cam (122) which is provided in between the right and left thrust bearing (121) and contacts both thrust bearings (121); the pair of mutually contacting faces (121b, 122b) of the right thrust bearing (121) and the operating cam (122) and the pair of mutually contacting faces (121b, 122b) of the left thrust bearing (121) and the operating cam (122) each comprising a first contact face (122b) and a second contact face (121b); the first contact face (122b) of each pair of contact faces (121b, 122b) defining in each case for the second contact face (121b) a guide path having a course such that, when the operating cam (122) is moved with respect to the thrust bearings (121) in a direction transverse to the longitudinal axis (101) of the cross bar (7) - in particular, is rotated about said longitudinal axis (101) - in order to allow the first (122b) and second (121b) contact faces to slide along each other, the thrust bearings (121) undergo displacement, defined by the guide path, in the direction (D, P) of said longitudinal axis (101) of the cross bar (7).

13. Brake device (100) according to Claim 12, wherein the guide paths extend in the circumferential direction of the longitudinal axis (101) of the cross bar (7) and preferably have a constant radius with respect to the longitudinal axis (101) of the cross bar (7).

14. Brake device (100) according to Claim 12 or 13, wherein the guide paths are mirror-symmetrical with respect to one another; each guide path extending from a first point (130) via a second point (131) to a third point

(132); the second (131) and third (132) points both being located, viewed in the direction of the longitudinal axis (101) of the cross bar (7), at a distance from the first point (130); the third point (132) being located, viewed in the direction of the longitudinal axis (101) of the cross bar (7), between the first (130) and second (131) points; and the first (122b) and second (121b) contact faces contacting each other, in the release state, in the first point (130) and, in the braking state, in the third point (132).

15. Brake device (100) according to one of Claims 12 to 14, wherein the first contact faces (122b) are provided on the operating cam (122) and the second contact faces (121b) are provided on the thrust bearings (121).

16. Brake device (100) according to one of Claims 12 to 15, wherein the operating cam (122) forms part of an operating pedal (118) which is mounted such that it may be rotated about the longitudinal axis (101) of the cross bar (7).

17. Brake device (100) according to one of the preceding claims, wherein each aforementioned braked wheel (11) comprises a suspension means (12) which counteracts upward swivelling of the wheel (11) and wherein the suspension means (12) of the right wheel (HR) and the suspension means (12) of the left wheel (HL) function independently of each other.

18. Brake device (100) according to Claim 17, wherein the suspension means (12) of each braked wheel (11) comprises a linear spring.

19. Brake device (100) according to Claim 18, wherein said spring (12) is compressed during upward swivelling of the respective braked wheel (11).

20. Brake device (100) according to one of the preceding claims, wherein each braked wheel (11) is accommodated in a wheel fork (115), the wheel fork (115) of the right braked wheel (HR) being fastened to the right end of the cross bar (7) such that it may swivel and the wheel fork (115) of the left braked wheel (11) being fastened to the left end of the cross bar (7) such that it may swivel.

21. Brake device (100) according to one of the preceding claims, wherein the right and left brake rods (119) are each substantially of one-piece construction.

22. Pull/push stroller (1) provided with a brake device (100) according to one of the preceding claims.

23. Stroller (1) according to Claim 22, wherein the stroller (1) comprises a seat (5) for the transporting of a person.

24. Stroller (1) according to Claim 23, wherein the seat is a seat (5) for a person younger than 6 years old, such as a carrycot for a baby or a high chair.

25. Stroller (1) according to one of Claims 22 to 25, wherein the stroller is a folding stroller (1).