WO2004065173A2

WO2004065173A2 - Powered vehicle for personal transport

Info

Publication number: WO2004065173A2
Application number: PCT/GB2004/000167
Authority: WO
Inventors: Steven Ruffle; Robert Menear; Roula Machaira; Wayne Mansell; David Davies
Original assignee: Sunrise Medical Limited
Priority date: 2003-01-22
Filing date: 2004-01-21
Publication date: 2004-08-05
Also published as: EP1590202A2; WO2004065173A3; GB2397558B; GB2397558A; GB0301438D0

Abstract

A powered vehicle for personal transport, including a frame (10); wherein the frame includes a first frame part (14) provided with ground engaging wheels, a second frame part (21) carrying or adapted to carry a seat (12), and a connecting assembly (20) operatively connected between said first and second frame parts and providing for relative movement of the second frame part between an operative first position in which it is spaced above the first frame part for use, and a second position in which it lies closer to the first frame part to reduce the volume occupied by the frame.

Description

Title: Powered vehicle for personal transport

Description of Invention

This invention relates to a powered vehicle for personal transport, which may include a removable drive assembly.

The type of vehicle in relation to which the invention has been devised is that whose purpose is to carry a person whose mobility is impaired. A specific example of this type of vehicle is a wheelchair, and the invention is described hereafter in relation to a wheelchair, although it is to be appreciated that the invention may also be applicable to other such vehicles, e.g. of the "powered scooter" type. Many such vehicles are adapted to be readily dismantled and/or folded, collapsed, or otherwise converted to a relatively compact configuration to enable them conveniently to be stored or transported in another vehicle. This dismantling or conversion may involve the removal of a drive assembly from the remainder of the vehicle. Such a removable drive assembly, which is usually at the rear of the vehicle, may comprise respective electric motors and reduction gearboxes for driving wheels provided at the sides of the drive assembly, steering of the vehicle being accomplished by controlling the electric motors so that their respective wheels are driven at different speeds from one another. The drive assembly may also include one or more electrical storage batteries to provide a power source.

In addition to the ability to remove the drive assembly (or possibly to remove individual drive assemblies for respective drivable wheels) powered wheelchairs typically provide for folding or collapsing, in order to reduce its volume, of a frame part of the wheelchair to which the drive assembly(s) is connectable. The most common method of reducing the envelope of the frame part of a powered wheelchair is to provide for respective side frame parts to be moved towards one another thereby reducing the width of the frame structure. To this end, the side frame parts are connected to one another by an arrangement of pivoted links, typically in an "X" arrangement. However, this arrangement may require considerable effort on the part of the user or an attendant, and the envelope of the frame structure still remains relatively large. Such envelope in many cases is dictated by the distance between front wheels (usually castors) or footrests carried by the respective side frame parts, and the handles typically provided at the top end of backrest-supporting parts of the side frame parts. To reduce this dimension, the user or attendant has to dismantle the chair into numerous smaller pieces, which is inconvenient.

It is broadly the object of the present invention to provide a vehicle which is able to be readily converted to a relatively compact configuration for storage or transportation purposes, utilising an alternative and more convenient approach to the folding or collapsing of a frame assembly and preferably to the removal of a drive assembly therefrom.

According to one aspect of the invention, we provide a powered vehicle for personal transport, including a frame; wherein the frame includes a first frame part provided with ground engaging wheels, a second frame part carrying or adapted to carry a seat, and a connecting assembly operatively connected between said first and second frame parts and providing for relative movement of the second frame part between an operative first position in which it is spaced above the first frame part for use, and a second position in which it lies closer to the first frame part to reduce the volume occupied by the frame.

According to another aspect of the invention, we provide a powered vehicle for personal transport; including a frame; a drive assembly including an electric motor and at least one ground-engaging wheel; and inter-engaging formations associated respectively with the drive assembly and with the frame and providing a releasable connection therebetween; wherein the frame includes a first frame part provided with at least one of said inter-engaging formations and with at least one ground engaging wheel, a second frame part carrying or adapted to carry a seat, and a connecting assembly operatively connected between said first and second frame parts and providing for relative movement of the second frame part between an operative first position in which it is spaced above the first frame part for use, and a second position in which it lies closer to the first frame part to reduce the volume occupied by the frame. The connecting assembly may include at least one elongate link member pivotally connected at or adjacent its one end to the first frame part and at or adjacent its other end to the second frame part. The movement of the second frame part relative to the first frame part may then involve a change in the inclination of such elongate link member relative to the frame parts: clearly the more closely to the vertical such elongate link member is oriented, the greater is the height of the second frame part above the first frame part.

Catch means may be provided for retaining the elongate link member in a position relative to the first frame part corresponding to the operative position of the second frame part. Preferably there are two said elongate link members, one at each side of the vehicle and they may be connected to respective seat side rail members of the second frame part.

For adjusting the overall height of the seat of the vehicle, when in use, first adjustment means is preferably provided for adjusting the attitude of the elongate link member when in its position relative to the first frame part corresponding to the operative position of the second frame part.

There may be second adjustment means for determining the angle at which the second frame part is set relative to the elongate link member when in its operative position, such adjusted angle determining the orientation at which the seat is disposed when in use, in respect of its tilting forwardly or rearwardly about an axis extending transversely of the vehicle.

A manually adjustable means such as a screw-threaded device may be provided for this purpose, or possibly a power-operable actuator. The or each elongate link member may be arranged in generally parallelogram configuration with a or respective further link member pivotally connecting the first and second frame parts.

A further aspect of the invention is concerned with the configuration of the inter-engaging formations providing the releasable connection between the frame of the vehicle and the drive assembly thereof. Although such inter- engaging formations are in broad terms known to provide for the releasable connection, in general they have required very accurate alignment between the respective formations on the frame and drive assembly for such formations to be able to be engaged with one another, making the connection of the drive assembly to the frame assembly an operation requiring great care. Bearing in mind that on occasions such a connection may be required to be made by a^" person whose mobility is to some extent impaired, it would be desirable if the inter-engaging formations could be designed to have their engagement and disengagement rendered more convenient.

With this further object in view, another aspect of the invention provides that the inter-engaging formations may be afforded by at least one first engagement member provided on one of the frame and the drive assembly and at least one second engagement member provided on the other of the frame and the drive assembly, the second engagement member affording a socket formation adapted to receive the first engagement member and which is of tapering configuration from a mouth portion to a base, the first engagement member being of complementary configuration, and the engagement members including guide surfaces which cooperate during entry of the first engagement member into the socket formation to align them with one another.

Preferably the socket formation includes a portion extending transversely of a direction faced by the mouth portion, and both the first engagement member and socket formation may be of generally curved configuration so that engagement therebetween requires relative angular and translational movement.

As well as the inter-engaging formations being configured such that their engagement is facilitated, it is also important that when engaged they should provide a secure and rigid connection between the frame and the drive assembly. With this object in view, a further aspect of the invention provides that the inter-engaging formations are so shaped that they are brought into rigid inter-engagement by the bending moment imposed on them in normal use of the vehicle. The aforementioned configuration of the first engagement member and socket formation, requiring relative angular and translational movement therebetween to engage them with one another or disengage them from one an other, may be such that they engage rigidly under the bending movement.

However alternative configurations of inter-engaging formations may be possible, for example the second engagement member may comprise elements which are so disposed relative to one another as to receive a first engagement member analogously to a socket but not forming an entire socket formation.

Preferably the drive assembly is provided with respective second engagement members at each side thereof, and the frame comprises frame members at respective sides of the frame and each having a first engagement member for engaging the corresponding socket formation on the drive assembly.

The drive assembly may be provided with means for supporting it, when not connected to the frame, at an attitude at which its second engagement members are presented so as to be easily engageable by the first engagement members provided on the frame.

Although the configuration . of the inter-engaging formations is preferably such that they are held in engagement with one another by the bending imposed on them in use, preferably catch means is provided to hold the inter-engaging formations in engagement. Such catch means may comprise respective catch members for each- set of inter-engaging formations, and preferably such catch members are releasable together by operation of a single release means. The invention will now be described by way of example with reference to the accompanying drawings, of which:

Figure 1 is a diagrammatic side elevation of a vehicle in accordance with the invention, with the frame and drive assembly of the vehicle connected to one another; Figure 2 is a view as Figure 1 of a vehicle modified in respect of details of its seat assembly, and showing the frame and drive assembly disconnected from one another;

Figure 2a shows a modification of the inter-engaging formations of Figure 2. Figures 3 a, b and c are plan views showing the releasable connection between the frame and drive assembly in different connected and disconnected conditions;

Figure 4a, b jand c are partial perspective views showing a seat height adjustment mechanism of a vehicle in accordance with the invention; Figure 5 is a side elevation illustrating a seat tilting adjusting mechanism of the vehicle;

Figure 6 is a side elevation showing part of the mechanism of Figure 5, in an alternative condition;

Figures 7a, b and c show an alternative embodiment of seat height and tilt adjustment mechanism, in alternative positions.

Referring firstly to Figure 1 of the drawings, this shows in side elevation an example of an electrically propelled vehicle, namely a wheelchair, in accordance with the invention. It comprises a frame indicated generally at 10 and a drive assembly indicated generally at 11, these main parts being releasably connected together as described in greater detail hereafter. The frame 10 supports a seat part indicated generally at 12 for occupation by a user of the wheelchair.,

In greater detail, the frame 10 includes first and second chassis or main frame members 14 which are provided one at each side of the wheelchair, extending forwardly and rearwardly thereof and parallel or generally parallel to one another. The frame members 14 are connected to one another by one_. or more transversely extending frame members one of which is indicated at 15 in Figure 3 of the drawings. Each frame member 14 carries at its front end a pivotal support 16 for a respective front castor wheel, enabling the castor wheel 17 to pivot about a vertical or generally vertical axis. At its rearmost end, each main frame member 14 is provided with an engagement formation comprising a member 18 which will be described in greater detail hereafter, for forming the releasable connection with the drive assembly 11. Each of the main frame members 14 further has pivotally connected to it, at a pivotal connection 19 adjacent its front end, a respective elongate seat-supporting link member 20, the two link members 20 carrying, at their opposite ends, the seat assembly 12.

The seat assembly 12 comprises two side rails 21, substantially parallel to one another and pivotally connected at 20a to the respective seat supporting link members 20. The seat side rails 21 carry a seat therebetween on which the occupant of the wheelchair can sit. Such a seat may comprise an element of flexible material supported by the side rails, or may include a rigid base. The side rails 21 further carry, at their rear ends, respective upwardly extending backrest side parts 22, and at their front ends respective footrest assemblies as shown at 23. They further carry armrest assemblies such as shown at 24. Different embodiments of backrest, footrest and armrest are shown at 22a, 23a and 24a in Figure 2: no further description of the backrest, footrest and armrest will be made as they may be entirely conventional and of any form. Preferably they are removable relatively easily from the side rails 21, and/or movable relative thereto for reducing the volume occupied by the seat assembly 12.

Preferably the armrests and side guard parts associated therewith are pivotable relative to the side rails 21, such that they can be folded inwardly towards each other and down on top of the seat to lie generally parallel to the seat and close thereto. The backrest including its side parts 22 may then be pivotable forwardly to overlie the seat and armrests. This effects a substantial reduction in the overall volume occupied by the seat assembly, and is an advantageous aspect of the present invention. The drive assembly 11 comprises laterally spaced drive wheels 30 which are independently drivable by respective electric motors 31 through appropriate reduction gearboxes. The wheels 30 and motors 31 are carried by a chassis structure which as illustrated is of box-like form 32 but which may be of any suitable construction. The chassis structure 32 carries one or more rechargeable electrical storage batteries for providing electrical power to the motors 31. For control by a user of the wheelchair, a manually operable control unit, e.g. of the "joystick" type would be provided at a position where it is readily accessible to the wheelchair user, e.g. carried at the foremost end of one of the armrest assemblies 24. Such a control unit would be connected electrically to the motors 31 and their power source by appropriate cabling, preferably incorporating one or more releasable connectors in order to accommodate the disengagement of the frame 10 from the drive assembly 11 when required. Such control of an electrically propelled wheelchair, enabling the user to control its movement forwardly, rearwardly and its steering (by differential driving of the motors 31 for the respective wheels 30) is generally known, and will not be described in any further detail since it does not form part of the present invention.

The drive unit further comprises respective rear support wheels 33 disposed a short distance rearwardly of the wheels 30 and carried by respective arms 34. The arms 34 are pivoted in the vicinity of the rotational axis of the wheels 30 and their movement is controlled by respective spring damper units 35. ^• These wheels 33 have two purposes, firstly to assist in prevention of the wheelchair's tipping over rearwardly if an attempt is made to climb an upward slope of too great an inclination, and secondly to support the drive assembly in a suitable orientation for easy connection to the frame part 10 of the wheelchair when they are disconnected from one another.

Adjacent the front end of the drive assembly 11, at each side thereof, it is provided with a respective second engagement formation provided by a member 36. The members 36 cooperate with the first engagement members 18 to provide a releasable connection between the frame 10 and drive assembly 11. The engagement members 18, 36 are of plate metal or other material of appropriate properties. Each member 36 defines a second engagement formation in the form of a socket or recess 37 (see Figure 2) which has a base 38 and curved walls 39, 40 which extend upwardly and forwardly and diverge from one another so that the recess has a forwardly presented mouth opening. The external profile of the first engagement formation 18 closely corresponds to the internal profile of the recess 37: thus the member 18 has a nose 41 which fits in the base 38 of the recess, and walls 42, 43 which correspond in profile to the walls 39, 40 of the recess respectively. The walls 39, 40 form guide surfaces which cooperate with the member 18 to guide it as it enters the recess.

It will be appreciated from a consideration of the shapes of the first engagement member 18 and recess 37 afforded by second engagement member

36 that the former is able to be introduced into the latter by a rearwards and downwards translational movement of the former, accompanied by some relative angular movement until the former fits closely within the latter, as shown in Figure 1. When the frame 10 and drive assembly 11 are disconnected, the centre of gravity of the drive assembly is so positioned that the drive assembly tilts back to be supported by its wheels 33 as shown in Figure 2, in which orientation the recess 37 is forwardly and upwardly presented so as to be easily entered by the engagement member 18. When the engagement members 18, 36 are engaged, the bending moment imposed on the connection between them is such that the members 18, 36 are urged into closer engagement and a rigid connection is the result. For holding them in engagement with one another, the drive assembly is provided at its sides with respective spring-loaded retaining catch members in the form of pins 45 (see Figure 3), each having a nose portion able to extend outwardly from an aperture 46 in the vicinity of the mouth of recess 37. The two pins 45 are connected by a cord 47 or the like, arranged so that pulling the cord 47 can move the two pins 45 towards one another against their respective biasing springs and cause their nose portions to be retracted from the mouths of the respective recesses 37. When the engagement member 18 is fully engaged in the recess 37, the pin is able to enter an aperture 48 in the engagement member to hold it in such full engagement.

The shape of the nose portions of the pins 45 may be tapered (as illustrated) so that when the engagement member 18 enters the recess 37 the respective pin is caused to be retracted against the force of its biasing spring without the cord 47 having to be operated to retract it. Figure 2a shows a possible modification utilising an alternative configuration of the engagement members as 18, 36. In this figure, and engagement member 36a comprises three pins 361, 362, 363 so positioned that an engagement member 18a of the illustrated shape is rigidly engaged between the pins when a member 14a to which the member 18a is connected is subject to a bending moment acting in the direction indicated by arrow M, relative to a member 11a to which the engagement member 36a is attached. The engagement members 18a, 36a are engaged and disengaged by a relative translational and angular movement therebetween. It is to be appreciated that the relationship between engagement members 18, 18a, and 36, 36a may be reversed, so that the engagement member 18 or 18a is fixed to the drive assembly 11 or 11a, while engagement member 36 or 36a is fixed to the frame member 14 or 14a.

Referring now to Figures 4a, b and c of the drawings, these illustrate one way in which the attitude of the seat-supporting link members 20 relative to the frame members 14, to which they are pivotally connected at 19, may be set, both for the purposes of enabling the folding of the frame part 10 of the wheelchair so that it occupies a smaller volume for storage purposes, and for setting the height of the seat when it is deployed for use, in order to suit differently-sized users.

Each of Figures 4a, b and c shows the two frame members 14 with a cross-member 15 extending transversely therebetween, and one of the link members 20 pivotally secured adjacent its front end, at 19, to the nearmost frame member 14. In the vicinity of the transverse member 15, the frame member 14 is provided with a pivot pin 50 on which is pivotably received a locking plate 51, the pivot pin 50 passing through a selected one of a number of spaced apertures 52 in the plate 51. The plate 51 is provided with an elongate slot 53 which extends from a position adjacent the end one of the apertures 52 with which the pin 50 is shown engaged in Figures 4a and 4b, and adjacent the opposite end of the plate the slot 53 has an end portion 54 extending transversely to the general direction of the rest of the slot. The link member 20 carries a pin 55 which engages in the slot 53, and moves therealong as the link member pivots relative to the frame member 14 about pivot 19. When the link member 20 is at its maximum upward inclination relative to the frame member 14, the pin 55 is able to enter the portion 54 at the end of slot 53, and the plate 51 pivot forwardly about its connection with the pin 50, so that the link member 20 is supported at such position. There may be a spring-loaded catch member part of which is shown at 56, cooperable with the pin 55 when it is in the part 54 of the slot to hold it in such position. When the seat assembly 12 of the wheelchair is required to be folded or collapsed down onto the lower part of the frame (i.e. to approach the frame members 14 as closely as possible), the catch member 56 if it is present must be released from engagement with the pin 55 and then the plate 51 can be pivoted about the pin 50 so that the pin 55 leaves the end part 54 of the slot 53 and enters the main part of the slot. Such pivoting of the plate 51 may be facilitated by pressing on a lever portion 57 thereof beneath the apertures 52. The relative position of the link member 20 and frame member 14 when the pin 55 has reached the lower end of slot 53 is clearly shown in Figure 4b: it will be appreciated that the seat assembly 12 has closely approached the frame member 14 thereby substantially reducing the volume occupied by the wheelchair.

The provision of the number of apertures 52 in plate 51 and the engagement of pin 50 in a selected one thereof enables an overall adjustment to be made in the height of the seat assembly when the link member 20 has reached its limiting position determined by engagement of pin 55 in the end portion 54 of the slot 53.

Referring now to Figure 5 of the drawings, this shows a means of adjusting the orientation of the seat assembly when in use. In this Figure (from which certain details such as the plate 51 and associated parts have been omitted for clarity) there is shown the link member 20 and its pivotal connection at 20a to a bracket 60 on the seat side rail member 21. A tilt actuator 61 comprises a body 62 which is pivotally connected at 63 to a member 64 fixed to the link member 20. At the opposite end of the body 62, a screw-threaded rotatable shaft 65 emerges, being rotatable by a hand knob 66 at its free end. A nut 67 is engaged with the screwthread of the shaft 65, the nut being pivotally connected to a bracket 68 on the seat side rail member 21. It will be apparent that turning the knob 66 causes the nut 67 to be moved one way or the other along the shaft 65, and hence adjust the angle of the seat side rail member 21 relative to the link member 20. The range of tilting movement of the seat assembly relative to the link member 20 is somewhat limited by the dimensions of the actuator 61 and its associated components, and in order to provide a range of tilting adjustment of the seat assembly which is available for different overall settings of the height of the seat assembly, the member 64 may be adjustably connected to the link member 20 at a selected one of a number of different positions therealong. Connection at a suitable position commensurate with the predetermined overall height of the seat assembly enables an acceptable range of seat tilting adjustment to be obtained at that height. When the seat assembly is required to be folded to lie as near as possible to the frame members 20, for storage or transportation of the wheelchair, the nut 67 may be disconnected from the bracket 68, so that the actuator may lie generally parallel to the link member 20 as shown in Figure 6 of the drawings. The seat assembly may then approach the frame members 14 much more closely than if the actuator remained connected.

Referring finally now to Figures 7a, b and c, these show diagrammatically an alternative arrangement by which adjustment of the overall height and the tilting of the seat assembly may be achieved. In this embodiment, link member 20 is shown pivotally connected between a frame member 14 and a seat member 21. The height of the pivotal connection between the link member 20 and the seat member 21 is determined by a sector plate 70 at the forward (and lowermost) end of the link member 20, having a number of apertures 71, a selected one of which is engaged by a pin 72 on the frame member 14. In generally parallel disposition to the link member 20, there is a further link 73 whose one end is pivotally connected to the frame member 14 at 74, and whose other end is engaged with a selected one of a number of apertures 75 provided in a plate 76 on the seat member 21. The one of the apertures 75 with which the link 73 is engaged determines the inclination of the seat member 21, e.g. rearwardly tilted as shown in Figure 7a or substantially horizontal as shown in Figure 7b. A suitable locking mechanism to permit folding of the seat member downwardly and rearwardly to approach the frame member 14 would, of course, be provided in this embodiment.

Although the vehicle described above incorporates a number of features, it is to be understood that the present invention may reside in certain of those features individually, i.e. not in combination with some or all of the other features described above and shown in the drawings. For example, features of the seat assembly, including the ability of its armrests and backrest to be folded or pivoted downwardly to reduce the volume occupied by the seat assembly, may form independent aspects of the invention. The nature of the connecting assembly between the frame part including frame members 14, and the upper frame part including the seat side rails 21, and the respective adjustment mechanisms operative between the links 20 and the seat assembly and the links 20 and frame member 14, may also constitute independent inventions. Such features may find application in a vehicle which does not have a removable drive assembly or assemblies: similarly the arrangement of the removable drive assembly and of the inter-engaging formations providing for such removal may be applicable to a vehicle which doesjiot have the illustrated seat assembly and associated part. In the present specification "comprises" means "includes or consists of and "comprising" means "including or consisting of.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. A powered vehicle for personal transport, including a frame (10); wherein the frame includes a first frame part (14) provided with ground engaging wheels, a second frame part (21) carrying or adapted to carry a seat (12), and a connecting assembly (20) operatively connected between said first and second frame parts and providing for relative movement of the second frame part between an operative first position in which it is spaced above the first frame part for use, and a second position in which it lies closer to the first frame part to reduce the volume occupied by the frame.

2. A vehicle for personal transport, including a frame (10); a drive assembly (11) including an electric motor and at least one ground-engaging wheel; and inter-engaging formations (18, 36) associated respectively with the drive assembly and with the frame and providing a releasable connection therebetween; wherein the frame includes a first frame part (14) provided with at least one of said inter-engaging formations (18, 36) and with at least one ground engaging wheel (30), a second frame part (21) carrying or adapted to carry a seat (12), and a connecting assembly (20) operatively connected between said first and second frame parts and providing for relative movement of the second frame part between an operative first position in which it is spaced above the first frame part for use, and a second position in which it lies closer to the first frame part to reduce the volume occupied by the frame.

3. A vehicle according to Claim 1 or Claim 2 wherein the connecting assembly includes at least one elongate link member (20) pivotally connected at or adjacent its one end (19) to the first frame part (14) and at or adjacent its other end (20a) to the second frame part (21).

4. A vehicle according to Claim 3 further comprising catch means for retaining the or each elongate link member in a position relative to the first frame part corresponding to the operative position of the second frame part.

5. A vehicle according to Claim 4 comprising first adjustment means for adjusting the attitude of the elongate link member relative to the first frame part when in its position corresponding to the operative position of the second frame part.

6. A vehicle according to any one of Claims 3 to 5 further comprising second adjustment means for adjusting the angle at which the second frame part is set relative to the elongate link member when in its operative position.

7. A vehicle according to Claim 5 or Claim 6 wherein said first and/or said second adjustment means is manually adjustable.

8. A vehicle according to any one of Claims 3 to 7 wherein there are two of said elongate link members, one at each side of the vehicle.

9. A vehicle according to Claim 8 wherein said elongate link members are connected to respective seat side rail members of the second frame part.

10. A vehicle according to Claim 9 wherein arm rest members and/or a backrest are pivotally connected to the or the respective side rail members.

11. A vehicle according to any one of Claims 3 to 10 wherein the or each elongate link member is arranged in generally parallelogram configuration with a or a respective further link member pivotally connecting the first and second frame parts.

12. A vehicle according to any one of Claims 2 to 11 wherein said inter- engaging formations are so shaped that they are brought into rigid inter- engagement by a bending moment imposed on them in normal use of the vehicle.

13. A vehicle according to Claim 12 wherein said inter-engaging formations are afforded by at least one first engagement member provided on one of the frame and the drive assembly and at least one second engagement member provided on the other of the frame and the drive assembly.

14. A vehicle according to Claim 13 wherein said first and second engagement members are engageable by relative translational and angular movement therebetween.

15. A vehicle according to Claim 14 wherein the or each second engagement member affords a socket formation adapted to receive the first engagement member and which is of tapering configuration from a mouth part to a base, the first engagement member being of complementary configuration and the engagement members including guide surfaces which cooperate during entry of the first engagement member into the socket formation to align them with one another.

16. A vehicle according to Claim 15 wherein the socket formation includes a portion extending transversely of a direction faced by the mouth portion, and both the socket formation and the first engagement member are of generally curved configuration.

17. A vehicle according to any one of Claims 13 to 16 wherein the drive assembly is provided with respective second engagement members at each side thereof, and the frame comprises frame members at respective sides thereof each having a first engagement member for engaging the corresponding second engagement member on the drive assembly.

18. A vehicle according to Claim 17 wherein the drive assembly is provided with means for supporting it, when not connected to the frame, at an attitude at which its second engagement members present the mouth portions of their socket formations such that they are easily engageable by the first engagement member on the frame.

19. A vehicle according to any one of Claims 2 to 18 further comprising catch means for holding the inter-engaging formations in engagement with one another.

20. A vehicle according to Claim 19 as a pendant directly or indirectly to Claim 13 comprising respective catch means for each second engagement member, cooperable with respective first engagement members therein.

21. A vehicle according to Claim 20 comprising a single release means for releasing said catch members together.

22. A vehicle for personal transport including a frame comprising a first frame part with at least one ground engaging wheel; a second frame part carrying or adapted to carry a seat; and a connecting assembly operatively connected between said first and second frame parts and providing for relative movement of the second frame part between an operative position in which it is spaced above the first frame part for use and a second position in which it is lowered to lie closer to the first frame part to reduce the volume occupied by the frame, wherein the connecting assembly includes at least one elongate link member pivotally connected at or adjacent its one end the first frame part and at or adjacent its other end to the second frame part, and there is provided adjustment means for adjusting the attitude of the elongate link member(s) relative to the first frame part when the link member(s) is in its position corresponding to the operative position of the second frame part.

23. A vehicle comprising a first frame part with at least one ground engaging wheel; a second frame part carrying or adapted to carry a seat; and a connecting assembly operatively connected between said first and second frame parts and providing for relative movement of the second frame part between an operative position in which it is spaced above the first frame part for use and a second position in which it is lowered to lie closer to the first frame part to reduce the volume occupied by the frame, wherein the connecting assembly includes at least one elongate link member pivotally connected at or adjacent its

__ one end the first frame part and at or adjacent its other end to the second frame part, and there is provided adjustment means for adjusting the attitude of the second frame part relative to the elongate link members(s) when the second frame part is in its operative position.

24. A vehicle substantially as hereinbefore described with reference to the accompanying drawings.

25. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.