CA2486861A1

CA2486861A1 - Child's pushchair comprising steering wheel-locking means

Info

Publication number: CA2486861A1
Application number: CA002486861A
Authority: CA
Inventors: Damiano Marella; Vincent Truong
Original assignee: Individual
Current assignee: Ampafrance SA
Priority date: 2002-05-21
Filing date: 2003-05-21
Publication date: 2003-11-27
Also published as: WO2003097426A1; FR2839935B1; FR2839935A1; EP1551685A1; AU2003249413A1

Abstract

The invention relates to a child's pushchair consisting of: at least one front steering assembly (16) comprising a fixed part which is solidly connected to the frame (15) of the pushchair and a mobile part which can rotate in relation to said fixed part along a first essentially vertical axis of rotation, said assembly bearing at least one wheel; and at least one rigid element which is mounted to the aforementioned fixed part, which moves in an essentially vertical manner and which co-operates with a housing provided for said purpose in the above-mentioned mobile part. In this way, means for locking/unlocking the rotation of the mobile part are formed in order to secure the mobile part with the fixed part in a central position in which the wheel or wheels are parallel to the rolling axis of the pushchair.

Description

CHILD'S PUSHCHAIR COMPRISING STEERING WHEEL-LOCKING MEANS
This invention relates to the domain of childcare, and more precisely child's pushchairs (referred to as "strollers" in the remainder of this description, this term covering all childcare devices with wheels and designed for the transport of one child or several children). More precisely, the invention relates to the use of efficient running means on strollers.
Strollers are usually provided with four wheels or wheel blocks, mounted at the end of uprights forming part of the stroller frame, or at the ends of a transverse axle installed free to rotate on the frame, particularly as a function of the selected folding method.
Front wheels installed free to rotate about a vertical axis have been proposed to improve usage comfort, such that they are free to pivot and thus facilitate direction changes. These mechanisms are not always efficient in practice, and means are provided for locking each wheel in a fixed position. It is not very easy to use these means, since it is necessary to bend down in front of each front wheel, and the wheels are usually dirty ...
As a result, users leave the wheels permanently in the fixed position (or free position), and do not benefit from the advantages of the choice between the two positions, depending on the type of ground.
Note also that the free position, although it is pleasant to use on uniform ground, introduces problems whenever it is required to go up a step or onto a pavement, or to move backwards. They then tend to move crosswise and to block movement of the stroller.
Strollers with three wheels have also been developed, with a single front wheel installed in the central position on a fork of the frame. In this case, it is not obviously possible to install the front wheel free to pivot for obvious efficiency and safety reasons (for example, the wheel could put itself crosswise at right angle and block the stroller). Therefore, strollers with three wheels systematically have a fixed swivel front wheel.
The purpose of the invention is particularly to overcome these disadvantages in the state of the art.
More precisely, one purpose of the invention is to provide a child's stroller fitted with efficient and easy to use swivel wheels.
In particular, the purpose of the invention is to provide such a stroller with good stability, or swivel control, running qualities, etc.

One particular purpose of the invention is to provide such a stroller with a front wheel (or wheel block according to the invention), placed in the central position.
Another purpose of the invention is to provide such a stroller with good comfort and ergonomy qualities, for the transported child and also for the person pushing the stroller.
Another particular purpose of the invention is to provide such a stroller that is adapted and / or adaptable to different types of ground and situations (steps, backwards movement, etc.), simply and efficiently.
Yet another purpose of the invention is to provide such a stroller that enables simple, efficient and ergonomic action on the swivel wheels.
These purposes, and others that will appear later, are achieved using a child's stroller comprising at least one swivel front assembly according to the invention, comprising a fixed part attached to the frame of the said stroller, and a part free to rotate about the said fixed part, about a first approximately vertical rotation axis and supporting at least one wheel, and at least one rigid element mounted on the said fixed part, free to move approximately vertically and cooperating with a housing provided for it in the said mobile part, forming means of locking / unlocking rotation of the said mobile part, designed to solidarise this mobile part and the said fixed part in a median position in which the said wheels) is (are) parallel to the running axis of the said stroller. The result is thus a stroller that is efficient in running and direction change, and is comfortable, based on a quite new approach to the front wheel system.
Advantageously, the said fixed part is suspended at the forwards end of at least one extension of the said frame, and the said wheels) is (are) carried by a fixed element of the said mobile part extending along an approximately horizontal second axis, offset backwards from the said stroller with respect to the said first axis.
During forward running, the projected distance between these two axes improves running comfort.
Preferably, the said fixed part and the said mobile part are fixed to each other by means of an axial attachment means extending along the said first rotation axis.
For example, it may be a shouldered screw or a pin.
Advantageously, the stroller comprises suspension means mounted between the said frame and the said fixed part. These suspension means may in particular comprise at least one spring mounted such that the said fixed part, the said springs) and the end of the said frame on which the said fixed part is supported, define a suspension triangle.
According to another advantageous aspect of the invention, the stroller comprises means of locking /
unlocking rotation of the said mobile part, fixing it with the said fixed part in a median position in which the said wheels) is (are) parallel to the running axis of the said stroller.
The said locking / unlocking means may thus 5 advantageously comprise a rigid element (for example a pin or plunger) installed on the said fixed part and cooperating with a housing provided for it in the said mobile part.
According to one advantageous characteristic, the shape of the said rigid element is conical or tapered.
This facilitates guidance and / or compensation of clearance of the rigid element.
Preferably, the said rigid element cooperates with a compression spring tending to bring it into its locking position when the locked position is selected.
According to one advantageous characteristic, the said locking / unlocking means are controlled remotely, using control means.
Preferably, the said control means include a lever or control button installed on the handlebar of the said stroller. The said control lever may in particular be installed on a control block also including a brake control.
Advantageously, the said locking / unlocking means are actuated by cable.
In this case, the said rigid element is preferably installed at the end of the said cable, and in that the said compression spring is installed on the said cable between the said rigid element and a stop. In particular, the said control means may act on the distance between the said stop and the distal end of the said rigid element.
According to another advantageous aspect of the invention, the said mobile part is free to move in rotation with respect to the said fixed part over a determined angular range with respect to the running axis of the said stroller.
The said angular range is preferably symmetrical about the running axis and may for example be~ of the order of 20 to 35° on each side of the said running axis.
According to yet another advantageous aspect of the invention, the said front wheel system comprises return means tending to bring the said mobile part into a median position, in which the said wheels) is (are) parallel to the running axis of the said stroller.
Advantageously, the said return means comprise a torsion spring installed on the said fixed part.
According to another advantageous characteristic of the invention, the said front wheel system includes means designed to facilitate movement of the said mobile part with respect to the said fixed part. The said means designed to facilitate the movement may in particular include at least one ball.
Advantageously, the said means of facilitating the movement comprise at least three balls, giving a plane bearing.
Preferably, each of the said balls is housed in a drum with a spherical base formed in the said fixed part (or the said mobile part) and circulates in a hemispherical section ball race in the said mobile part (or the said fixed part).
According to a first advantageous embodiment of the invention, the said front assembly forms a suspended front wheel system.
According to a second advantageous embodiment of the invention, the said stroller includes two wheels or wheel blocks extending along the prolongation of two forward longitudinal members respectively, and each provided with the said locking means.
According to a third advantageous embodiment of the invention, the stroller includes a single front wheel or wheel block, installed along the prolongation of a first swivel fork.
In this case, the said wheel or the said wheel block is preferably installed on a second fork free to rotate about a horizontal axis with respect to the said first fork, and in that it has suspension means between the said first and second forks.
Other characteristics and advantages of the invention will become clearer after reading the following description of preferred embodiments of the invention, given as simple illustrative examples that are in no way limitative, and the appended figures, wherein:
- Figure 1 shows a principle diagram for a first embodiment of a stroller using a front wheel system according to the invention;

- Figure 2 illustrates the front wheel system and the front end of the stroller in figure 1, in more detail;
- Figure 3 shows a view of the mobile part of the front wheel system in Figure 2;
- Figure 4 shows a view of the fixed part of the front wheel system in Figure 2;
- Figure 5 shows the locking pin of the front wheel system in Figure 2;
- Figure 6 illustrates the pin control handle in Figure 5, and braking means;
- Figures 7A to 7C diagrammatically illustrate a few variant embodiments of the invention;
- Figure 8 is a second embodiment of a stroller according to the invention, with 4 wheels;
- Figure 9 shows a simplified sectional view of locking means for each front wheel of the stroller in Figure 8;
- Figure 10 shows the front part of a 3-wheel stroller, according to another embodiment of the invention;
Figure 11 shows a sectional view of means of connecting the wheel and the frame in Figure 10;
- Figure 12 shows a sectional view of means of locking the stroller in Figure 10.
Therefore, the invention relates to a new approach for locking the front wheels) of a stroller.
Figure 1 shows a principle diagram for a first embodiment of such a stroller, using a suspended front wheel system (this diagram deliberately being simplified and not to scale, in particular the suspended front wheel system being enlarged with respect to the rest of the stroller), classically including a folding frame 11, supporting a hammock 12 (or possibly another device in which one child or several children may sit). The frame 11 is fitted with two back wheels 13 installed on an axis 14.
On the front, the frame 11 is fitted with a fork 15 (or a single element corresponding to the junction between the two branches of the fork). According to the invention, a front wheel system 16 is installed suspended at the end of this fork 15.
This front wheel system 16 illustrated in more detail in Figure 2, is formed from two parts: a fixed part 21 fixed to the frame 11, and a mobile part 22 free to move with respect to the fixed part 21.
The fixed part 21 and the mobile part 22 form an assembly (the front wheel system) . The mobile part 22 is free to move about an approximately vertical axis 23, such that the front wheels) can pivot with respect to the frame 11.
Note that the term "fixed" applied to the fixed part 21 relates to this rotation about the axis 23. This fixed part 21 is nevertheless free to move slightly with respect to the frame, to achieve a suspension function.
Therefore, the fixed part 21 is suspended from the fork 15 by a horizontal axis 24 so as to form a suspension triangle, with one or more suspension elements such as a spring 25.
The mobile part 22 is installed as a pivot link with the fixed part 21, using a shouldered screw controlling 5 tightening of the two parts. In the case of a single wheel, the wheel may be installed directly on the mobile part 22.
In the case of a two-wheel block, the block has a vertical axis offset from another horizontal axis on 10 which the wheels are installed. The vertical axis fits into a housing 26 provided for this purpose in the mobile part 22, to be fixed to it.
In forward running, the projected distance between these two axes improves the running comfort, by centring the two front wheels in the running direction.
On the other hand in reverse running, this distance significantly reduces control comfort, since the front wheels move into an arbitrary position, and / or get blocked in one of their end positions (25° from the running direction, as will become clearer later).
This problem is solved by providing means of locking the front wheel system in a fixed position.
We have seen that this principle is already known in itself. However, in its known form it is not very practical. Therefore according to one particular aspect of the invention, these locking means are controlled remotely from the handlebar.
The locking means are illustrated in Figure 5. A pin 51 is installed at the end of a cable passing through a duct 52 with a compression spring 53. This assembly is fixed onto the fixed part 21. The duct 52 stops in contact with the ring 54, and the spring 53 also bears on this ring.
The remote control can vary the cable length and therefore the length L of the pin (depending on whether or not the spring 53 is compressed).
In a first position, the pin 51 (or plunger) that extends vertically, does not act (since the spring is compressed). In a second position (the spring pushing the pin), the spring dips into a housing provided for this purpose in the mobile part 22. The fixed and mobile parts are then fixed and the swivel is blocked.
Obviously, the housing is positioned such that the wheels are straight (parallel to the back wheels). If the pin 51 is not facing this housing (in other words if the wheels are not straight) during locking, the compression spring 53 acts on the pin so that it locks as soon as the front wheels move into the straight position. The return means described below facilitate this operation.
A method of controlling these locking means is illustrated in Figure 6. A single control block 61 contains a braking control 62 (known in itself) and the locking control 63, that can be in two stable positions P1 and P2 corresponding to the two positions of the pin 51.
The handle 63 acts on the cable 64 through step down gear means 65 pulling or releasing the cable 64.

Figure 3 illustrates the mobile part 22. In this embodiment, means 31 and 32 are provided to contain the wheel axles (they could also be suspended).
Note the presence of the housing 33 designed to hold the plunger 51 and a guide path 34 for the plunger whenever the wheels are not straight.
The ball races 35, 36 and 37 with a hemispherical cross section can also be seen, cooperating with balls installed in the fixed part 21.
Figure 4 illustrates this fixed part 21. As already mentioned, the front wheel system is free to pivot about a vertical axis. In order to limit forces and noise due to friction between the plates, four balls 41, 42, 43, 44 (for example) are provided housed in cylinders 45, 46, 47 and 48 with a spherical base. The result is thus a non-sliding bearing between the two plates.
Therefore these four balls, which may for example have a diameter of 8 mm, act as four connection points, giving a plane bearing (with a degree of redundancy).
Due to the ball races 35 to 37 mentioned above, there is no need to mark the mobile part 22 with the impression of the balls. Note that these races are limited such that rotation is limited to a determined range on each side of the rest position (wheels straight), for example 25° on each side.
Moreover, the fixed part 21 is provided with a torsion spring 49 tending to bring the mobile part 22 into its straight position (front wheels) pointing in the same direction as the back wheels).

The ends 491, 492 of this spring come into contact with the stops 391, 392 (Figure 3) provided for this purpose.
Thus, without manipulating the product, the front wheel system moves into the straight position as soon as the weight is removed from it (the front wheels no longer touch the ground), for example, to go onto a pavement, or to move backwards. This also facilitates locking operations described above.
Obviously, the invention could be used in many other forms without departing from the scope of the invention.
For example, Figures 7A to 7C diagrammatically illustrate different assembly techniques for the wheels 71 and for the connection between the front wheel system 72 and the frame 73.
Furthermore, methods of assembly, fixing and use of the different components may vary as a function of available technical needs and solutions.
Finally, the different aspects improving the general principle of the invention (return spring, offset control of the plunger, balls, etc.) obviously only describe advantageous but non-compulsory options.
According to a second embodiment, the invention may be used on a stroller fitted with four wheels or a wheel block, and with two forward longitudinal members at the end of which swivel wheels (wheel blocks) are provided.
Figure 8 shows a side view of an example of such as stroller. A longitudinal member 81 extends on each side, on which a pusher 82 can slide during folding. A swivel wheel 83 is provided at the bottom of the longitudinal member.
To achieve this, a fixed part 91 fixed to the longitudinal member 81, and a part 92 free to rotate about this fixed part 81, is provided as illustrated on the sectional view in Figure 9. The wheel 83 is installed on this mobile part 92.
According to the principle described above, the fixed part carries a pin 93 free to move vertically in translation. In the locked position, the pin 93 fits into a housing 94 provided for it in the mobile part 92. The fixed and mobile parts are then fixed and the wheel can no longer swivel.
When the pin 93 is raised (position illustrated on Figure 9), the mobile part 92 may turn freely about the axis 95 connecting the two parts.
According to the approach mentioned above, the pin 93 is preferably controlled remotely, and is activated by cable 97, for example from the pusher. Return means 96 act on the pin, tending to move it into the locked position when the actuation cable is slack Obviously, in the case of a 4-wheel stroller, symmetric means need to be provided on each side. A
specific actuation could be provided for each side, for example in the form of two sliding buttons provided on each pusher. It will also be possible to make a central control, simultaneously activating the two locking means.

Figure 10 shows a view of the front part of a three-wheel stroller according to a third embodiment of the invention.
The single front wheel 101 is supported on a first 5 fork 102, itself fixed to a second fork 103 installed on the stroller frame, and extending approximately in the vertical direction. This second fork is free to rotate to allow the wheel to swivel.
The first fork 102 is connected to the second fork 10 103 by horizontal hinge pins on each side, enabling movement of the first fork. Suspension means consisting of a spring 104 control this movement so as to make the stroller more comfortable.
Note that the rotation axis 105 of the wheel is 15 offset backwards with respect to the vertical axis of the second fork 103.
Figure 11 shows a sectional view showing the link between the frame and the second fork 103. It comprises a fixed part 111 formed at the end of the frame, and a mobile part 112 free to turn about a vertical axis with respect to the fixed part 111. This mobile part comprises solidarisation means 113 fixing the second fork and means 114 of holding the suspension spring 104.
Based on the same principle as mentioned above, a locking pin free to move in the zone 115 can fix the fixed part 111 and the mobile part 112 together. This aspect is illustrated more precisely in Figure 12.
Figure 12 shows a pin 121, which has a tapered end in this case. Its displacement is controlled by a cable free to move in a duct 122. Another spring 123 is provided, tending to bring the pin back into the locked position in which the pin 121 penetrates into the housing 124 defined in the mobile part.

Claims

17

1. Child's stroller, characterised in that it comprises at least one swivel front assembly, comprising a fixed part attached to the frame of the said stroller, and a part free to rotate about the said fixed part, about a first approximately vertical rotation axis and supporting at least one wheel, and at least one rigid element mounted on the said fixed part, free to move approximately vertically and cooperating with a housing provided for it in the said mobile part, forming means of locking / unlocking rotation of the said mobile part, designed to solidarise this mobile part with the said fixed part in a median position in which the said wheel(s) is (are) parallel to the running axis of the said stroller.

2. Stroller according to claim 1, characterised in that the said fixed part is suspended at the forwards end of at least one extension of the said frame, and in that the said wheel(s) is (are) carried by a fixed element of the said mobile part extending along an approximately horizontal second axis, offset backwards from the said stroller with respect to the said first axis.

3. Stroller according to either claim 1 or 2, characterised in that the said fixed part and the said mobile part are fixed to each other by means of an axial attachment means extending along the said first rotation axis.

4. Stroller according to any one of claims 1 to 3, characterised in that it comprises suspension means mounted between the said frame and the said fixed part.

5. Stroller according to claim 4, characterised in that the said suspension means comprise at least one spring mounted such that the said fixed part, the said spring(s) and the end of the said frame on which the said fixed part is supported, define a suspension triangle.

6. Stroller according to any one of claims 1 to 5, characterised in that the shape of the said rigid element is conical or tapered.

7. Stroller according to any one of claims 1 to 6, characterised in that the said rigid element cooperates with a compression spring tending to bring it into its locking position when the locked position is selected.

8. Stroller according to any one of claims 1 to 7, characterised in that the said locking / unlocking means are controlled remotely, using control means.

9. Stroller according to claim 8, characterised in that the said control means include a lever or control button installed on the handlebar of the said stroller.

10. Stroller according to claim 9, characterised in that the said control lever is installed on a control block also including a brake control.

11. Stroller according to any one of claims 8 to 10, characterised in that the said locking / unlocking means are actuated by cable.

12. Stroller according to claim 11, characterised in that the said rigid element is installed at the end of the said cable, and in that the said compression spring is installed on the said cable between the said rigid element and a stop.

13. Stroller according to claim 12, characterised in that the said control means act on the distance between the said stop and the distal end of the said rigid element.

14. Stroller according to any one of claims 1 to 13, characterised in that the said mobile part is free to move in rotation with respect to the said fixed part over a predetermined angular range with respect to the running axis of the said stroller.

15. Stroller according to claim 14, characterised in that the said angular range is of the order of 20 to 35°
on each side of the said running axis.

16. Stroller according to any one of claims 1 to 15, characterised in that the said front wheel system comprises return means tending to bring the said mobile part into a median position, in which the said wheel(s) is (are) parallel to the running axis of the said stroller.

17. Stroller according to claim 16, characterised in that the said return means comprise a torsion spring installed on the said fixed part.

18. Stroller according to any one of claims 1 to 17, characterised in that the said front wheel system includes means designed to facilitate movement of the said mobile part with respect to the said fixed part.

19. Stroller according to claim 18, characterised in that the said means of facilitating the movement comprise at least one ball.

20. Stroller according to claim 19, characterised in that the said means of facilitating the movement comprise at least three balls, giving a plane bearing.

21. Stroller according to either claim 19 or 20, characterised in that each of the said balls is housed in a drum with a spherical base formed in the said fixed part (or the said mobile part) and circulates in a hemispherical section ball race in the said mobile part (or the said fixed part).

22. Stroller according to any one of claims 1 to 21, characterised in that the said front assembly forms a suspended front wheel system.

23. Stroller according to any one of claims 1 to 21, characterised in that it includes two wheels or wheel blocks extending along the prolongation of two forward longitudinal members respectively, and each provided with the said locking means.

24. Stroller according to any one of claims 1 to 21, characterised in that it includes a single front wheel or wheel block, installed along the prolongation of a first swivel fork.

25. Stroller according to claim 24, characterised in that the said wheel or the said wheel block is preferably installed on a second fork free to rotate about a horizontal axis with respect to the said first fork, and in that it has suspension means between the said first and second forks.