GB2278655A

GB2278655A - A wheel assembly for a pushchair

Info

Publication number: GB2278655A
Application number: GB9410739A
Authority: GB
Inventors: Gianluca Perego
Original assignee: PEREGO PINES GmbH; Peg Perego Pines SpA
Current assignee: PEREGO PINES GmbH; Peg Perego Pines SpA
Priority date: 1993-06-04
Filing date: 1994-05-27
Publication date: 1994-12-07
Anticipated expiration: 2014-05-27
Also published as: GB9410739D0; ITMI931173A1; ITMI931173A0; IT1271562B; GB2278655B; DE4419314A1

Description

1 2278655 Child's Pushchair and Wheel Assembly therefor_ This invention

refers to an innovative wheel assembly for pushchairs and to a pushchair fitted with such wheel assembly. Pushchairs with pairs of front wheels freely swivelling to easily negotiate curves, and pairs of rear wheels which can be braked to prevent undesirable movement of the pushchair are well-known in the known technique. The braking action on the rear wheels, which is usually achieved by means of a blocking pedal, effectively ensures fir.n control of the pushchair when it is left on a slope facing in its normal direction of movement. This braking action can however prove to be insufficient whenever the pushchair is left on a descent in a position perpendicular to the slope. In fact, in these conditions the pushchair can roll, under the force of its own weight, by swivelling round on its braked wheels and rolling on its swivel wheels, so as to end up facing towards the maximum gradient. Even though, after making a complete turn in the direction of the slope, the brake applied to the rear wheels prevents any further movement, the rotating movement alone can prove to be extremely dangerous. Just imagine, for example, the consequences of this movement if the slope was part of an embankment or the like: if the pushchair was on the edge of the emj'jankment, its simple rotation could cause it to fall over the edge.

2 One possible solution could be to provide the front wheels with a controlled braking system, similar to that of the rear wheels. This solution however is virtually inapplicable due to the obvious difficulty in operating a brake so far from the normal position in which the pushchair is pushed. The general scope of this invention is to obviate the aforementioned problems by providing an improved swivel wheel assembly with an innovative locking device on the front wheels and a pushchair fitted with said wheel assembly. This scope is achieved according to the invention by providing a wheel assembly pivoting around a pivoting axis, intended for use in a children's pushchair, comprising means for blocking rotation of the wheel around its rolling axis, the blocking means being actuated when the wheel reaches at least one pre- established position around the pivoting axis. A further scope is achieved according to the invention, by providing a children's pushchair comprising a pair of front wheel assemblies and a pair of rear wheel assemblies, a first pair being made with wheel assemblies as mentioned above and, the other pair comprising controllable braking means. The innovatory principles of this invention and its advantages with respect to the known technique will be more clearly evident from the following description of a possible exemplificative embodiment applying such

3 principles, with reference to the accompanying drawings, in which: figure 1 shows a partial cutaway plan view of a front swivel wheel for a pushchair according to the invention; - figure 2 shows a view along the line II-II of figure 1; - figure 3 shows a schematic plan view of.a pushchair according to the invention; - figure 4 shows a view similar to that of figure 2, but with the wheel in the braked condition. With reference to the figures, figure 1 shows a swivel wheel assembly of the front pair of steering wheels of a pushchair according to the invention. The wheel assembly, generically indicated by reference 10, comprises a fastening bush 11 into which is coupled one tubular end 12 of the frame of the pushchair. The bush 11 is rotatingly fitted with a sleeve 13 of a wheel bearing assembly 17 rotatingly supporting an axle 14. Pivoted on the axle 14 are two opposing wheels 15, 16 between which the wheel bearing assembly is substantially contained. The axis of the axle 14 is off-centre compared to the axis of rotation of the sleeve so as to provide the known swivelling movement of the front wheel assembly. As can be clearly seen in figure 2, pivoted on the wheel bearing assembly 17, according to an axis 19, is a bell crank 18 with its substantially horizontal upper end bearing a tooth or cam 20 sliding along a cam surface 21 protruding radially integral with the bush 11. The other end of the bell crank bears a pin 22, protruding parallel 4 to the axle 14 so as to mesh between the teeth of a gear wheel 23 integral with at least one of the wheels. As can be seen in figure 2, when the wheel is normally directed (that is to say in the normal forward running and steering positions), the cam surface 21 pushes the end of the bell crank downwards, against the action of a spring 24, so that the pin 22 remains disengaged from the teeth of the gear wheel 23 and the wheels are thus free to rotate. Figure 3 shows a plan view of the basic structure of the pushchair (generically indicated by reference 28). In particular, it shows the pair of front swivel wheels 10, 10' as described above, and a pair of rear wheels 25, 251 of the known type with known controlled braking means, for example operated by a rod 26 controlled with the foot, as is well known to the expert in the field. The structure of the pushchair frame, for example of the type made of metal tubes, advantageously made foldable, is of a per se known type and will not therefore be further described or shown herein. The continuous line in figure 3 shows the position of the swivel wheels during normal running, while the broken line shows the position assumed by the same wheels during rotation of the pushchair substantially around a point determined by the rear wheels in the locked position. In this position, the front wheels are disposed substantially at right angles with respect to the normal running direction of the pushchair. Figure 4 shows one of the front wheels when disposed in said right-angled position. In this position the tooth 20, biased by the spring 24, enters into a recess 27 in the cam surface 21 so that the bell crank can rotate and fit the pin 22 between the teeth of the gear wheel 23 thereby blocking the respective wheel. The shape of the recess in the cam is madg, in such a way as to enable the tooth to slide easily and effortlessly in and out of the recess. For example, the tooth and recess can have a matching triangular shape, as can be clearly seen in figure 4. At this point it will be clear how the intended scopes have been achieved. When in use, during the normal movement of the pushchair the right- angled condition of the front wheels is rarely reached and so the front wheels are free to rotate. Moreover, whenever it is necessary to swing the pushchair round in a full circle, the condition of temporary blockage of the wheels when they reach the 90 position is no problem whatsoever, since it is normal during this movement to tip the pushchair slightly backwards, thereby releasing the front wheels. When the pushchair is left, the pedal 26 blocking the rear wheels is operated as usual, thereby preventing undesirable movement of the pushchair even on slopes in its normal direction of movement. Whenever the pushchair is left in the braked condition on a direct slope slanted (for example at right angles) with respect to its normal direction of movement, the weight of the pushchair itself 6 will tend to cause it to rotate in the direction of the maximum gradient. As soon as this rotatory movement begins, the front wheels will set themselves at right angles as shown in figure 3 (where the necessary angle of rotation of the pushchair has been exaggerated for the sake of clarity) and the above-described mechanism which blocks the rotation of the front wheels consequently comes into action, thereby halting the rotation of the pushchair. At this point it will be clear that the intended scopes have been achieved by providing a pushchair with a innovative wheel brake which acts perfectly to prevent both lateral rotation of the pushchair as well as rolling movements. It is obvious that the pushchair can be structured in the same way as a known pushchair in which the conventional front steering wheels are replaced by the abovedescribed front wheels. The front wheels 10, 10' are advantageously made specular to each other, so that the downhill wheel always blocks during the start of the rotatory movement of the pushchair. The foregoing description of an embodiment applying the innovatory principles of this invention is obviously given by way of example in order to illustrate such innovatory principles and should not therefore be understood as a limitation to the sphere of the invention claimed herein. For example, as can be easily imagined by the expert in the field, the structure of the bell crank may differ from

7 the one shown, just as the position of the cam surfaces and of the actuating tooth may differ, without detriment to the locking of the wheel when turned at right angles with respect to the normal direction of movement. For example, it is possible to provide two recesses in the cam surface disposed in diametrically opposed.positions with respect to the pivoting axis of the wheel so that blockage occurs in both directions of rotation of the pushchair, on bpth front wheels.

1. Wheel assembly for use in a child's pushchair, the assembly comprising a wheel which is movable about a pivot axis and which is rotatable about a rolling axis, and means for blocking rotation of the wheel around the rolling axis, the blocking means being actuated when the wheel reaches at least one pre-established position around the pivot axis.

2. Wheel assembly according to claim 1, wherein the blocking means comprises a leverage having one movable end providing a pin for engagement in locking teeth which are fixed relative to the wheel, movement of the leverage being controlled by a cam surface defined on the pivot axis whereby to engage the pin between respective locking teeth when the wheel reaches said pre-established position.

3. Wheel assembly according to claim 2, wherein the leverage comprises a bell crank pivotally mounted intermediate the ends thereof on an axis which is parallel to the rolling axis of the wheel, the other end of the leverage providing cam follower means slidably engaging with the cam surface, whereby to rotate the leverage so as to engage the pin in the teeth upon the 9 - wheel reaching said pre-established position.

4. Wheel assembly according to claim 3, wherein the cam surface comprises a recess into which when said pre-established position is reached, the cam follower means in the form of a tooth engages under pressure of a biassing spring.

5. Wheel assembly according to any of claims 2 to 4, wherein the cam surface protrudes radially from a bush which forms a fastening casing and a swivel axle defining the pivot axis for the wheel assembly.

6. Wheel assembly according to any of the preceding claims, wherein the wheel comprises two rollers which are coaxially juxtaposed, and between which the blocking means is substantially contained, the blocking means acting upon at least one of the two rollers, 7. Wheel assembly according to any of the preceding claims, wherein said pre-established position coincides with a wheel position substantially at right angles with respective to the wheel position in which the wheel assembly is fitted on a pushchair to face in the normal direction of movement of the pushchair.

8. A, - s h - -.zi -," 9C' 11 -! comprising a pair of -

Claims

front wheel assemblies, each of a first of the pairs according to any of

the preceding Claims, and the other of the pairs providing controllable braking means.

9. A pushchair according to claim 8, wherein the first pair of wheel assemblies is the front pair of the pushchair.

10. A pushchair according to claim 8 or 9, wherein said pre-established position for blocking the wheels of the first pair of wheel assemblies is substantially a right angle with respect to the normal direction of movement of the pushchair- 11. A pushchair according to any of claims 8 to 10, wherein the wheel assemblies of the first pair are made specular to each other.

12. Wheel assembly for use in a child's pushchair, substantially as hereinbefore described with reference to the accompanying drawings.

13. A puschair substantially as hereinbefore described with reference to the accompanying drawings.