GB2178374A - Foldable wheeled vehicles - Google Patents

Abstract

Movement of a first member 19 of a foldable vehicle frame relative to a second member 12 thereof is utilised to pivot a wheel about a pivot axis 27 such that the wheel is disposed in a more compact relationship with the frame when the latter is in its folded condition than when it is in its erected condition. The inventions particularly described with respect to a folding pushchair. <IMAGE>

Description

SPECIFICATION Foldable wheeled vehicles This invention relates to wheeled vehicles having foldable frames which are movable between erected and folded conditions, and particularly, but not exclusively, to foldable pushchairs for infants.

Pushchairs are provided with frames which can be folded from an erected condition in which they are used for transporting infants seated or laid therein to a folded condition in which they occupy considerably less space than when in the erected condition and therefore may be more readily stored.

In many cases some or all of the wheels of the pushchair protrude significantly from the frame thereof when the latter is in its folded condition, and it is an object of this invention to enable such wheels to have a more compact relationship with the frame when the frame is in its folded condition than when the frame is in its erected condition.

The invention provides a wheeled vehicle having a foldable frame which is movable between erected and folded conditions, wherein a wheel of the vehicle is pivotally mounted about a pivot axis spaced from its axis of rotation and fixed relative to a first member of the frame, means being connected to a second member of the frame, which second member moves relative to said first member during movement of the frame between its erected and folded conditions, for causing said wheel to be pivoted about said pivot axis during said relative movement of said members such that said wheel is disposed in a more compact relationship with said frame when said frame is in its folded condition than when it is in its erected condition.

The axis of rotation of said wheel preferably pivots towards said first member during movement of said fram from its erected to its folded condition.

In a presently preferred embodiment of the invention, described hereinafter, said wheel is a rear wheel of the vehicle, said first and second members of the frame respectively forming base and back legs of the frame whem the frame is in its erected condition, said first and second members being pivotally interconnected at end portions thereof adjacent said wheel such that said second member extends substantially parallel to said first member when said frame is in its folded condition.

Also in the preferred embodiment a mounting means for said wheel is pivotally connected with respect to said first member about said pivot axis and supports said wheel for rotation about its axis of rotation, and said means connected to said second member com prises a first link pivotally connected thereto and to a slider means mounted for sliding movement along said first member for causing said slider means to slide along said first member during said relative movement of said members and a second link pivotally connected to said slider means and to said wheel mounting means for causing said wheel mounting means to be pivoted about said pivot axis thereof during sliding movement of said slider means along said first member.

Alternatively said mounting means connected to said second member may comprise gear teeth means meshingly engaged with gear teeth means mounted on said wheel mounting means such that on pivotal movement of said first member relative to said second member said gear teeth means cooperate to cause said wheel mounting means to pivot about said pivot axis.

The preferred embodiment comprises a pushchair for an infant in which each of the two rear wheels thereof operates as aforesaid.

In order that the invention may be well understood, the preferred embodiment thereof referred to above will now be described in more detail by way of example only, reference being made to the accompanying drawings, in which: Figure 1 is a perspective sketch of a puschair for an infant shown with its frame in an erected condition; Figure 2 is a side view of part of the pushchair including a rear wheel thereof; and Figure 3 is a side view of the pushchair corresponding to that shown in Figure 2 but with the frame in a folded condition.

Referring first to Figure 1 there is shown a pushchair 1 for an infant. The pushchair comprises a foldable frame 2 which is illustrated in an erected condition in which it has base, and inclined front and rear structures 3,4 and 5. Rear and front wheels 6,7 are attached to the frame (only one set of front wheels being visible in Figure 1) adjacent respective corners of the base structure 3 thereof. A handle 8 is mounted to upper side members 9 of the front structure 4 and a seat structure 10 is pivotally attached to the upper side members 9 by pivot devices 11 so as to be able to adopt a plurality of positions relative to the frame including the forward facing inclined position illustrated, a corresponding rearward facing inclined position and substantially horizontal rearward and forward facing positions.

The base structure 3 includes two side members 12 the opposite ends of which are interconnected by two transverse members 13 (shown in dotted line) and a removable storage tray 14 fits over and is located by said members 12, 13.

The front structure 4 comprises the two upper side members 9 referred to above and two lower side members 15 which are pivotally connected to the front of the base structure by pivot connections 16. Each upper side member is pivotally connected to a respective lower side member by a pivot connection 17 such that in the erected condition of the frame the lower side member is parallel to but slightly spaced from the upper side member with the top end portion of the lower side member extending alongside the bottom end portion of the upper side member.In this condition the lower and upper side members on each side of the frame can be restrained against relative pivotal movement at their pivot connections by means of respective locking clips 18 which are mounted on the upper side members for pivotal movement about the longitudinal axis thereof and are able to snap-fit over the lower side members to retain the upper and lower side members in parallel relationship.

The rear structure 5 comprises two side members 19 each of which is pivotally connected at respective ends by pivot connections 20 and 21 to the base and the front frame structures 3 and 4.

To move the frame from its erected condition illustrated to a folded condition, the locking clips 18 are released, and the upper and lower side members 9 and 15 of the front structure are pivoted about their pivot connections 17; members 15 being caused to pivot in the direction of arrows A about pivot connections 16, members 9 in the direction of arrows B about pivot connections 17 and members 19 in the direction of arrows C about pivot connections 20.

Thus, the frame adopts a folded condition with members 9, 15 and 19 all extending substantially parallel to side members 12 of the base frame as shown in Figure 3.

The front wheels 6 of the pushchair are mounted on the ends of lower side members 15 of the front frame structure and therefore move into more compact relationship with the base structure when the frame is moved into its folded condition as described above.

The rear wheels 7, however, are mounted to the base frame structure and in order to cause these wheels to be automatically moved into a more compact relationship with the frame when in its folded condition so that the rear wheels do not protrude significantly from the frame when the frame is in this condition use is made of the movement of the side members 19 of the rear structure relative to the side members 12 of the base structure. This feature of the pushchair will now be described with reference to Figures 2 and 3 in respect of one rear wheel 7, although it will be appreciated that the other rear wheel in the illustrated embodiment is provided with a like arrangement.

In Figures 2 and 3, the end portions of the base side member 12 and the rear side member 19 adjacent the wheel 7 are mounted in respective fittings 22 and 23 which are fast therewith and are pivotally interconnected to provide the pivot connection 20 between side members 12 and 19 mentioned above. The wheel 7 is mounted for rotation about its axis of rotation 24 in a bearing member 25 which is carried by arm 26. The arm 26 is pivotally mounted about a pivot axis 27 on the base side member fitting 22 and thus together the member 25 and arm 26 form mounting means pivotally mounting the wheel 7 about axis 27 which is fixed relative to base side member 12 and spaced from the wheel's axis rotation 24.

A first link 28 is pivotally connected to the rear side member 19 about a pivot axis 29 provided by the fitting 23 thereof and to a slider means, formed as a collar 30, which is mounted for sliding movement along the base side member 12 for causing the collar 30 to slide along the member 12 during relative pivotal movement of the members 12 and 19. A second link 31 is pivotally connected to the collar 30 about a pivot axis 32, provided thereby, which in the illustrated arrangement is also the pivot axis for the pivotal connection between the collar and the first link 28, and to the arm 26 of the wheel mounting means about a pivot axis 33 for causing the arm 26 to be pivoted about the pivot axis 27 during sliding movement of the collar 30 along the base side member 12.

When the frame is moved from its erected condition shown in Figure 2 to its folded condition shown in Figure 3, the rear side member 19 is pivoted towards the base side member 12 about pivot axis 20 in the direction of arrow C. The first link 28 between the side member 19 and the collar 30 causes the collar to move along the base side member 12 as indicated by arrow D, and the second link 31 between the collar 30 and the arm 26 causes the latter to be pivoted about axis 27 in the direction of arrow E with the wheel's axis of rotation 24 being pivoted towards the base side member 12. Movement of the frame from its folded condition to its erected condition causes the links and collar to move in the reverse directions to those indicated by the arrows C, D and E.

From the foregoing it will be appreciated that pivotal movement of the rear side member 19 relative to the base side member about axis 20 causes, through links 28 and 31 and collar 30, the wheel 7 to be pivoted about pivot axis 27 such that the wheel becomes disposed in a more compact relationship with the pushchair frame when the frame is in its folded condition illustrated in Figure 3 than when it is in its erected condition as illustrated in Figure 2. This feature is also shown in Figure 2 by the illustration therein in chain-dotted line of the position of the wheel relative to the base side member 12 to which it is pivoted when the frame is folded.

It is to be understood that means other than those illustrated may be employed to utilize relative movement of the rear side member 19 and base side member 12 to cause pivotal movement of the wheel about axis 27 in order that the wheel may be disposed in a more compact relationship with the frame when the latter is in its folded condition than in its erected condition. For example, a gear wheel or sector may be connected fast with the rear side member such that gear teeth thereof meshingly engage with gear teeth of a gear wheel or sector mounted fast with the arm 26, or its equivalent, such that on pivotal movement of the side member 19 relative to the side member 12 the gear teeth cooperate to cause the arm to pivot about the axis 27.

Claims (8)

1. A wheeled vehicle having a foldable frame which is movable between erected and folded conditions, wherein a wheel of the vehicle is pivotally mounted about a pivot axis spaced from its axis of rotation and fixed relative to a first member of the frame, means being connected to a second member of the frame, which second member moves relative to said first member during movement of the frame between its erected and folded conditions, for causing said wheel to be pivoted about said pivot axis during said relative movement of said members such that said wheel is disposed in a more compact relationship with said frame when said frame is in its folded condition than when it is in its erected condition.

2. A wheeled vehicle as claimed in claim 1, wherein the axis of rotation of said wheel pivots towards said first member during movement of said frame from its erected to its folded condition.

3. A wheeled vehicle as claimed in claim 1 or 2, wherein said wheel is a rear wheel of the vehicle, said first and second members of the frame respectively forming base and back legs of the frame when the frame is in its erected condition, said first and second members being pivotally interconnected at end portions thereof adjacent said wheel such that said second member extends substantially parallel to said first member when said frame is in its folded condition.

4. A wheeled vehicle as claimed in claim 1, 2 or 3 wherein a mounting means for said wheel is pivotally connected with respect to said first member about said pivot axis and supports said wheel for rotation about its axis of rotation, and wherein said means connected to said second member comprises a first link pivotally connected thereto and to a slider means mounted for sliding movement along said first member for causing said slider means to slide along said first member during said relative movement of said members and a second link pivotally connected to said slider means and to said wheel mounting means for causing said wheel mounting means to be pivoted about said pivot axis thereof during sliding movement of said slider means along said first member.

5. A wheeled vehicle as claimed in claim 3, wherein a mounting means for said wheel is pivotally connected with respect to said first member about said pivot axis and supports said wheel for rotation about its axis of rotation, and wherein said means connected to said second member comprises gear teeth means meeshingly engaged with gear teeth means mounted on said wheel mounting means such that on pivotal movement of said first member relative to said second member said gear teeth means cooperate to cause said wheel mounting means to pivot about said pivot axis.

6. A wheeled vehicle as claimed in any one of the preceding claims comprising a pushchair for an infant.

7. A wheeled vehicle as claimed in claim 6, wherein each of two rear wheels thereof ocmprises a respective said wheel.

8. A wheeled vehicle substantially as herein described with reference to the accompanying drawings.