WO1994017769A1

WO1994017769A1 - A chassis

Info

Publication number: WO1994017769A1
Application number: PCT/GB1994/000241
Authority: WO
Inventors: Graham Reginald Nicholls; Lester Harris
Original assignee: Sungift Plc
Priority date: 1993-02-11
Filing date: 1994-02-09
Publication date: 1994-08-18
Also published as: GB9302767D0; GB2277062A; GB2277062B; GB2277062A8

Abstract

It is known to provide self-propelled vehicles for the disabled and infirm. Such vehicles generally have rigid, fabricated chassis to which are rotatably secured three or four support wheels. At least one of the support wheels is driven, typically by an electric motor. A disadvantage of such known vehicles is that they virtually have to be custom-built to suit differently sized purchasers thereof. The disclosure relates to a chassis (10) for a vehicle. The chassis (10) comprises a forward portion (11) and a rear portion (12), the two portions being releasably securable one to the other. The forward portion (11) includes a front sub-chassis (19) and an intermediate sub-chassis (20) rigidly securable one to another. The axial spacing of the front and intermediate sub-chassis (19, 20) is adjustable, thereby permitting the ready manufacture of various vehicles of different sizes from a common chassis design. A support (40) for a passenger seat is secured to the intermediate sub-chassis (20), and a handlebar (18) whereby the chassis (10) may be steered is secured to the front sub-chassis (19). Thus, adjustment of the length of the forward portion (11) automatically adjusts the position between the seat support (40) and the handlebar (18).

Description

A CHASSIS

This invention relates to a chassis for a floor or ground engaging vehicle. In particular, but not exclusively, the invention relates to a chassis for a vehicle intended for use by infirm or disabled passengers.

The invention also relates to a vehicle incorporating such a chassis.

The market for self-propelled vehicles for disabled and infirm people is increasing steadily. It is known to provide such a vehicle comprising a comparatively rigid, fabricated chassis to which are rotatably secured three or four support wheels. At least one of the support wheels is driven, for example by means of an electric motor and a suitable transmission. At least one of the wheels, usually a different wheel from the driven wheel or wheels, is steerable by means of a steering mechanism and, e.g, a handlebar or steering wheel.

A passenger seat is supported in a mid-portion of the vehicle, such that the passenger may readily operate the steering wheel or handlebar and such controls as may be provided for, e.g., actuating the drive motor; operating lamps and indicators; and operating windscreen wipers

(if present) .

Commonly, such vehicles include a canopy or shell which defines a passenger cabin. However, other designs are available which lack the canopy or shell. If the canopy or ^"shell is present, the handlebar or steering wheel and the passenger seat are enclosed within the cabin defined thereby.

Vehicles of this general kind are intended for use, e.g., on pavements, inside buildings and within hospital grounds. Generally, the range, maximum speed and power output of such a vehicle are limited for safety reasons, and it is therefore impractical for such vehicles to be used on the open road. However, there is no other technical reason why such a vehicle could not be employed on the open road, if desired.

A disadvantage of existing vehicles for disabled and infirm peopie is that the small size of any passenger cabin defined by the chassis and, if present, any canopy or shell attached thereto means that the seating arrangement is adjustable in only a very small range. Therefore, previously proposed vehicles have not been capable of accommodating passengers of a great range of sizes. Hitherto if any adjustment has been provided, it has been confined to a small range of movements of the passenger seat within the cabin. Generally, the available range of movements has been so small as to be of almost no practical use. Thus it is common for manufacturers of vehicles for the disabled and infirm virtually to custom-build the vehicles, according to the size of the intended passenger. Clearly, this is disadvantageous since the production costs of the vehicles are thereby made very high.

According to a first aspect of the invention there is provided a chassis for a floor or ground engaging passenger vehicle comprising a forward portion; a rear portion securable to the forward portion; means secured to the forward portion for receiving a passenger support; floor or ground engaging means secured to at least one of the portions whereby a vehicle incorporating the chassis may travel over a floor or the ground; and a grippable means disposed in juxtaposition to the means for receiving a passenger support, wherein the forward portion includes a front sub-chassis and a further sub-chassis intermediate the front sub- chassis and the rear portion, the two sub-chassis being securable one to the other in a plurality of positions whereby the axial length of the forward portion may selectively be varied, the means for receiving a passenger support being secured to the intermediate sub-chassis and the grippable means being secured to the front sub-chassis. An advantage of this arrangement is that by providing for adjustment for the length of the front portion of the chassis, the size of the passenger space of a vehicle incorporating the chassis may be greatly varied. The adjustment may be carried out during assembly of a vehicle including the chassis, thereby enabling a manufacturer of vehicles to offer a range of vehicle sizes whilst only having to stock a single chassis design.

A further advantage accrues from the location of the passenger support receiving means on the intermediate sub-chassis and the grippable means on the front sub-chassis. Adjustment of the length of the front portion of the chassis automatically causes the support receiving means and the grippable means to move closer together or further away from one another as desired. Since a large passenger is likely to have a longer arm reach than a smaller passenger, the position of the passenger for gripping of the grippable means is automatically optimized on adjustment of the length of the front portion of the chassis to suit a particular size of passenger.

Preferably, the position of the grippable means is adjustable relative to the front sub-chassis. This feature advantageously allows passengers whose arm reach lengths are not commensurate with the overall sizes of their bodies to attain a comfortable position.

Conveniently, the front sub-chassis and the further sub-chassis include complementary, elongate, mutually engaging means securable one to another in a plurality of axial positions one relative to the other; and means for effecting said securing in a plurality of such positions. This feature allows for the ready adjustment of the length of the front portion, without the need for specialised adjusting apparatus.

Conveniently, the front sub-chassis includes a rearwardly extending, elongate, open ended, hollow member and the intermediate sub- chassis includes forwardly extending, elongate member which is slidably receivable in the hollow member via the open end thereof, whereby the front and intermediate sub-chassis support one another in a desired relative axial position. Thus, in preferred embodiments, a portion of the intermediate sub- chassis may be inserted into a portion of the front sub-chassis in the manner of a telescope, again providing for easy adjustment of the length of the portions.

Preferably, the hollow member includes at least a first transverse aperture and the forwardly extending member includes a plurality of transverse apertures which may respectively be brought into register with the first aperture on axial sliding of the forwardly extending and hollow members one inside the other; and the means for effecting securing includes a pin or bolt means releasably securable in the first aperture and one of the plurality of apertures in register therewith, thereby to lock the hollow and forwardly extending members in a desired relative axial position.

Thus, locking of the two parts of the forward portion of the chassis may be rapidly and effectively accomplished.

In particularly preferred embodiments of the invention, the hollow member may extend horizontally axially centrally along the front sub- chassis when the chassis is in an assembled condition; additionally, the forwardly extending member may extend from the intermediate sub-chassis such that it is readily slidably receivable in the hollow member on assembly of the chassis.

An advantage of this feature is that there is a need for only a single, rearwardly extending, hollow member and a single, forwardly extending member. Thus, the number of components needed to manufacture the chassis is kept to a minimum. Additionally, the assembly of the chassis is facilitated by the need only to insert a single forwardly extending member into a corresponding rearwardly extending one.

The hollow member may preferably include secured thereto one or more laterally extending support members, whereby a portion of a vehicle body may be supported on the front sub-chassis.

Thus, the hollow member may advantageously constitute the central member of a "backbone"-type vehicle chassis. Such chassis types are known to be particularly robust.

Similarly, the intermediate sub-chassis may preferably include secured thereto one or more laterally extending support members, whereby a portion of a vehicle body may be supported on the intermediate sub- chassis.

This feature confers advantages similar to those of the presence of lateral support members on the hollow member. The invention also relates to a chassis comprising forward and rear chassis portions, wherein the forward portion includes a locating member projecting therefrom and the rear portion of the chassis may preferably include a seating adapted to receive the locating member, whereby the intermediate sub-chassis and the rear portion may be coupled together such that relative axial movement therebetween is prevented.

This represents a convenient way of connecting the forward portion of the chassis to the rear portion thereof, whilst allowing ready dismantling of the chassis.

Preferably, the locating member and the seating therefor are such that, when the intermediate sub-chassis and the rear portion are coupled together, relative rotational movement therebetween about an axis, which when the chassis is assembled is vertically perpendicular to the longitudinal axis of the chassis, is prevented.

Conveniently the locating member comprises a generally horizontal bar projecting from the forward portion, and the seating comprises at least one cup adapted to receive the bar in such a way that movement of the bar relative to the cup in a direction transverse thereto is prevented.

It is preferable that the cup includes a member extending to cover a portion of the opening thereinto, the bar being shaped so that it may only be inserted into the cup past said member in a limited range of orientations. The cup may conveniently be shaped to allow the bar to adopt an orientation outside said range once the bar has passed said member.

The chassis may include a plurality of cups as aforesaid.

Additionally or alternatively, the intermediate sub-chassis may preferably include extending generally vertically therefrom a first bracing member, and the rear portion may include extending generally vertically therefrom a second bracing member, said bracing members being disposed such that, on locating of the locating member in the seating a portion of the first bracing member remote from the intermediate sub- chassis is disposed proximate a portion of the second bracing member remote from the rear portion, means being provided for securing the bracing members one to the other in the region of their mutual proximity.

These features, which may be used mutually exclusively or in .conjunction with one another, help to ensure that the coupling between the forward portion of the chassis and the rear portion thereof may be made fully rigid.

The first bracing member may conveniently be constituted as the means for receiving a passenger support. In particularly preferred embodiments, the first bracing member is constituted as a seat tube. A seat support pin securable to a passenger seat may be received within the seat tube.

In particularly preferred embodiments, the height of the seat support pin in the seat tube is adjustably securable. It is preferable that the floor or ground engaging means includes a plurality of wheels rotatably secured thereto to support the chassis on a surface and permit travel of the chassis thereon.

However, it is possible to construct the chassis of the invention employing, e.g., skids, walking feet, tracks, gear wheels intended to engage a fixed track or many kinds of inflatable support member.

Conveniently, the rear portion of the chassis includes a pair of wheels rotatably secured thereto and interconnected by an axle. The axle preferably includes first and second portions drivingly interconnected by a clutch means, whereby slipping of the clutch means occurs when the torques acting on the respective wheels differ by more than a predetermined amount. This feature allows, e.g., the two rear wheels of a vehicle incorporating the chassis to rotate at different speeds while the vehicle is cornering.

Preferably, the forward portion of the chassis includes at least one wheel rotatably secured thereto. Conveniently, this wheel is steerable.

In a particularly preferred embodiment of the invention, the forward portion includes a pair of steerable wheels rotatably secured thereto; and a steering mechanism. Preferably, the steering mechanism includes a steering column. It is convenient that the steering column includes a lower part operatively connected to the steerable wheels via a plurality of link means and an upper part pivotably secured to the lower part. This arrangement advantageously allows adjustment of the position of, e.g., a grippable means secured to the steering column relative to the forward portion of the chassis.

Preferably, the grippable means is secured to the upper part of the steering column.

The grippable means may conveniently be constituted as a handlebar or a pair of handlebars. Alternatively, the grippable member may be a lever or a steering wheel.

The rear portion of the chassis may in preferred embodiments include a motor means and a drive transmission means whereby the output of the motor means may cause driving motion of the floor or ground engaging means. In preferred embodiments, suitable switch gear may be employed to allow for selective actuation of the motor means. A suitable gearbox and/or control means may also be employed to allow for reversing of the drive.

The invention also relates to a vehicle including a chassis according to any preceding claim.

Preferably, the vehicle includes a passenger seat received in the passenger support receiving means. The vehicle also conveniently includes a floor or other body part supported on the laterally extending member or members of the front sub-chassis and/or the intermediate sub- chassis.

Optionally, the vehicle may include a cabin having an entry/exit aperture for a passenger, the chassis, the aperture and the cabin being dimensioned to permit ready entry into an exit from the cabin by a disabled or infirm passenger.

There now follows a description of a preferred embodiment of the invention, by way of example, with reference being made to the accompanying drawings in which:

Figure 1 is a perspective view of a chassis according to the invention, in its fully assembled condition; Figure 2 is an enlarged perspective view of part of the chassis of Figure 1, showing adjustment of the length of the forward portion of the chassis;

Figure 3 is perspective view showing the rear portion of the chassis separated from the forward portion;

Figure 4 is a side elevation showing the method by which the chassis parts of Figure 3 may be coupled together; and

Figure 5 is a side elevation showing the parts of Figure 4 in the fully coupled condition. Referring to the drawings, there is shown a chassis 10 for, e.g., a vehicle for disabled or infirm passengers. The chassis shown is intended to constitute the basic structure of a vehicle suitable for carrying a single passenger. However, it is contemplated that a similar chassis could be employed in a vehicle having multiple seating. The chassis comprises a rear portion 12 and a forward portion 11. The rear portion 12 and the forward portion 11 are releasably securable one to the other in a manner to be described below. The forward portion 11 includes a means for receiving a passenger support, in the form of a seat tube 13 incorporating a bracing member 14. The chassis 10 includes a plurality of floor or ground engaging means in the form of front 16 and rear 17 wheels secured in pairs respectively to the forward 11 and rear 12 portions of the chassis. A handlebar 18 constituting a grippable means is disposed in juxtaposition to the seat tube 13. The forward portion 11 of the chassis 10 comprises two sub-chassis portions, a front sub-chassis portion 19 and an intermediate sub-chassis portion 20. The two sub-chassis portions 19, 20 are releasably secured together in a manner to be described below such that the length of the forward portion 11 of the chassis 10 may be readily adjusted. The seat tube 13 is secured to the intermediate sub-chassis 20, and the handlebar 18 is secured to the front sub-chassis 20. Thus, adjustment of the length of the forward portion 11 of the chassis causes alteration of the distance between the seat tube 13 and the handlebars 18. The front sub-chassis 19 includes a backbone member 22 which is a square section, hollow bar extending horizontally from the front of the front sub-chassis 19 to the rear thereof. The backbone member 22 is open at its rear end. A series of members 23 extend laterally of the backbone member 22 to either side thereof, the upper surfaces of the lateral members being generally flush with the top of the square section backbone member. The backbone member and the lateral members serve to support a floor or other body part when the chassis is incorporated in a vehicle. The intermediate sub-chassis comprises a T-shaped member 24 having an elongate, round bar 25 projecting forwardly from the end of the stem 24a of the T. The round bar is adapted to be received in the hollow portion of the backbone member 22 to connect the front 19 and intermediate 20 sub-chassis together.

A pair of through going apertures" 26, 28 has been formed in each vertical side wall of the backbone member 22 at spaced locations. As best shown in Figures 2, 3 and 5 the round bar 25 has formed therein a series of through going, transverse bores 29. The spacing of the successive transverse bores 29 in the round bar 25 corresponds to the spacing of the pairs of apertures 26, 28 in the backbone member 22. On insertion of the round bar 25 into the backbone member 22, the round bar 25 slides telescopically within the backbone member 22 until the forward portion 11 of the chassis is approximately of a desired length. The positions of the intermediate 20 and front 19 sub-chassis are then adjusted slightly relative to each other so that a pair of holes 29 in the round bar 25 are respectively in register with the pair 26, 28 of through going bores in the backbone member 22. A suitable pair of bolts 30 may then be passed through the respective in register pairs of apertures 26, 29;28, 29 and tightened to lock the intermediate sub-chassis 20 to the front sub-chassis 19. The intermediate sub-chassis 20 includes a pair of laterally extending members 31 which are similar to the laterally extending members 23 of the backbone member 22. The function of the laterally extending members 31 secured to the intermediate sub-chassis 20 is to provide for support of one or more body parts of a vehicle in which the chassis may be incorporated. A pair of fillet plates 32 interconnects the T-shaped member 24 of the intermediate sub-chassis 20 and the laterally extending members 31 thereof.

The crosspiece of the T-shaped member 24 constitutes a locating member 24b which is used in conjunction with the bracing member 14 referred to above to link or assist in linking the forward and rear chassis portions 11, 12 together.

As shown in the drawings, the locating member 24b is a square section hollow tube. A similar square section tube member 34 of approximately the same length is disposed at the forward end of the rear chassis portion 12. Respective tongues 35 extend forwardly of either end of the square section member 34 of the rear chassis portion, enclosing and projecting beyond said ends. The forwardmost ends 35a (best shown m Figure 3) of the tongues are directed downwardly at an angle and cranked inwardly towards the stem 24a of the T-shaped member. Inboard .of the respective tongues are disposed a pair of respective cup base members 36 shaped to interconnect the lowermost edge of each tongue and the square section member. Thus, at either end of the square section member the front wall of the square section member, one of the tongues and one of the cup base members define a cup which is open at its upper end and also at its innermost end.

It will therefore be appreciated that the ends of locating member 24b may be inserted into the respective cups. The shape of each cup is such as to prevent axial separation of the locating member 24b and the square section member 34 once the locating member 24b has been inserted into the cups.

The base of each cup is directed downwardly at a slight angle towards the forward end thereof, by virtue of the shape of the tongue member 35 and the cup base member 36 secured thereto. Respective, further tongue pieces 37 secured to top of the square section member 34 protrude forwardly thereof. On location of the locating member 24b into the respective cups, the upper surface of the

■locating member 24b abuts against the lower surfaces of the further tongue pieces 37. Thus, the rear portion 12 of the chassis 10 is prevented from tilting downwards away from the locating member 24b during assembly.

It will be appreciated that the shape of the cups is such that the locating member 24b cannot simply be dropped vertically thereinto. It is necessary for the intermediate sub-chassis 20 and the rear portion 12 to be offered up at an angle to one another, as shown in Figure 4. Once the locating member 24b has been manoeuvred into the cups, however, the rear portion 12 and the intermediate sub-chassis 20 may readily be adjusted by tilting them so that they lie in common plane, as shown in Figure 5. This action secures the locating member 24b firmly in the cups.

The upstanding seat tube 13 incorporating bracing member 14 is secured at the union of the crosspiece (locating member) and stem 24b, 24a of the T-shaped member 24.^" The tube 13 has a through going transverse bore 38 formed therein. A support pillar 40 of a suitable seat may be inserted therein. The support pillar 40 has a plurality of through going bores 41 which may selectively be brought into register with the bore 38 formed in the seat tube 13. A bolt or lockable pin 42 may be used to secure the seat pillar into the seat tube by tightening it into the in-register apertures 38, 40. In this manner, the height of the support pillar 40 relative to the seat tube 13 may be readily adjusted.

The chassis 10 is shown in Figures 1 to 5 lacking a seat. The seat would ordinarily be mounted e.g. by means of bolts, on the top 40a (Figure 5) of the support pillar 40.

The bracing member 14 extending rearwardly of seat tube 13 is a U-shaped cup rigidly secured at its base to the rear of the seat tube. A pair of in-register, through-going bores 43 are formed in the respective limbs 14a, 14b of the U-shaped cup. When the chassis is assembled, the U-shaped cup receives the upper end of a bracing pillar 44 rigidly secured to extend upwardly from the square section member 34 of the rear portion 12. A through going bore 46 is formed in the upper end of the bracing member 44. On assembly of the chassis, this bore 46 comes into register with the bores 43 formed in the limbs 14a, 14b of the U-shaped cup. A pin 47 may then be inserted through the aligned bores to secure the bracing member 14 and bracing pillar 44 together.

It will be appreciated that the U-shaped cup and the locating member cup arrangement ensures that the intermediate sub-chassis 20 and the rear portion 12 are securely locked together against movement in all directions when the pin 47 is inserted. However, the pin 47 may readily be removed to allow dismantling of the chassis.

The pin 47 is of a kind having a central rod which is spring loaded and shaped such that, under normal circumstances, a pair of ball bearings loosely captive at one end of the pin 47 are pressed outwardly to ensure secure locking of the pin in the apertures. However, when it is desired to remove the pin a button 48 may be depressed which releases the spring biassing on the ball bearings and thereby allows withdrawal of the pin. The pin has an enlarged head 49 at the end opposite the ball bearings, which acts as a reaction surface.

It will be seen that the rear portion 12 includes a plurality of frame members which between them support an electric motor 50, a transmission in the form of a gear 52 and chain drive 53 and the rear axle 54 of the chassis.

The rear axle 54 is suspended below the rear portion 12 in respective pillow blocks disposed on opposite sides of the rear portion. The rear axle in the embodiment shown is, essentially, a live axle having a ground engaging wheel 17 secured at each end thereof. The axle is a two-piece axle, with the two portions thereof interconnected at approximately the mid-point between the wheels 17 by a friction clutch 55. The purpose of the friction clutch is to allow each of the rear wheels 17 of the chassis to rotate at a different speed. This is desirable when, for example, a vehicle incorporating the chassis turns a corner and the torque on one of the rear wheels differs from that acting on the other rear wheel. The friction clutch 55 may be chosen or set to operate only when the torque difference between the two rear

.wheels exceeds a predetermined minimum. By this means, the drive from the motor 50 may be transmitted to both rear wheels equally via the gear and chain mechanism, e.g. when the vehicle is travelling in a straight line on an even surface.

The forward end of the front portion of the chassis incorporates a front, transverse chassis member 56 which is rigidly secured, e.g. by welding, beneath the backbone member, transverse thereto. The end 22a of the backbone member extends forwardly beyond the transverse chassis member 56, and is directed upwardly therefrom at a slight angle to the backbone member. Four fillets 58 are secured, e.g. by welding, across the respective corners defined at the intersection of the transverse chassis member 56 and the backbone member 22. Thus, the connection of the transverse member 56 to the backbone member 22 is particularly rigid.

Each outermost end of the transverse member supports a kingpin assembly 59. A front wheel and stub axle assembly 16, including a brake 60, is pivotably secured to the kingpin assembly. A respective steering arm 61 extends generally rearwardly of each kingpin assembly 59. A tie rod 62 extending transversely across the chassis pivotably interconnects the steering arms 61 in the conventional manner of an Ackerman steering geometry.

In the embodiments shown, the right hand steering arm extends rearwardly beyond the point of attachment of the tie rod. A steering linkage member 64 is pivotably secured at one end to the rear end of the extended steering arm. At the other end, the linkage member is pivotably secured to the free end of a steering actuator arm 65.

The steering actuator arm 65 is rigidly secured to the lower end of a steering column 66. The lowermost portion of the steering column 66 is pivotably received in a steering bearing housing 67 which is turn is rigidly secured to the forwardmost end 22a (ie. the upwardly directed end) of the backbone member 22.

The steering column 66 extends upwardly and has rigidly secured thereto at its upper end the handlebars 18. The steering column 66 is a two-piece item. The upper portion 66a is secured to the lower portion 66b by means of a friction bearing 73 which allows pivotable movement of the upper portion 66a relative to the lower portion 66b along a generally vertical arc when the assembled chassis 10 is upright. It will therefore be appreciated that the upper end 66a of the steering column, and hence the handlebars 18, may be adjusted in position relative to the forward portion 11 of the chassis.

It will also be appreciated that steering of a vehicle incorporating the chassis may readily be effected by turning the handlebars 18, to actuate the Ackerman steering mechanism via the various components thereof.

The embodiment shown includes a brake lever 68 secured to the handlebars 18 and operatively connected to a pair of drum brakes 60 disposed respectively in the hubs of each of the front wheels 16, by means of a brake cable linkage. A first cable is guided by a cable sheath to a cable eye 69 disposed approximately three quarters of the way down the steering column. The end of the first cable is secured in the pinch bolt of a cable yoke which pulls^'on the mid point of a further cable, a portion of which is presented as a loop passing between two further cable eyes 70 secured to a plate forming part of the steering actuator arm 65. A pair of cable sheaths guide the further cable to either side of the further eyes towards the respective front wheels. The ends of the further cable are exposed at yet further cable eyes 71 mounted on fillet members respectively secured to the steering arms. Each exposed end of the further cable terminates in a nipple which is received in the actuating lever of a drum brake assembly of proprietary design. The reaction member of the drum brake assembly is secured to the steering arm at an appropriate point by means of a bolt. Thus, actuation of the brake lever 68 causes simultaneous actuation of two drum brake assemblies operable on the front wheels of the vehicle.

It will be appreciated that the chassis of the invention can be manufactured in a variety of configurations. The embodiment described includes a pair of steerable front wheels 16 and a pair of driven rear wheels 17. However, it is equally possible, for example, to devise a version of the chassis in which there is only a single, steerable front wheel. Other possible arrangements include the provision of a pair of steerable front wheels as in the embodiment described, and a single, driven rear wheel. Yet a further possibility is the provision of the chassis in the form of a motorised two-wheeled cycle or scooter.

The preferred embodiment is constructed from mild steel, primarily by means of welding. However, it will be appreciated that the chassis may be constructed in a variety of materials. A great many metals are suitable for the construction of the chassis. For example, aluminium alloys and possibly even titanium could be employed if very lightweight versions are desired.

Moreover, composite materials such as fibre and polymer matrices or laminates may be used for some or all of the components of the chassis. The chassis could even be made from timber if desired.

A vehicle incorporating the chassis will include a large number of components additional to those described in detail. For instance, it may be desirable to provide padding for certain parts of the chassis to prevent a user thereof from suffering injury thereof in the event of an accident. In particular, the handlebars 18 may be provided with a covering.

A completed vehicle incorporating the chassis would usually include an electrical system to provide power for lights, indicator lamps, windscreen wipers and a warning hooter or klaxon. The electrical system would also incorporate a relay or solenoid such as solenoid 72 and suitable circuitry permitting actuation of the drive motor 50. In the embodiment shown, the solenoid is shown secured to a plate which in turn is secured just below the handlebars 18 on the steering column 66. A pivotable actuator plate is disposed to depress the actuator rod of the solenoid 72. This arrangement is particularly preferred because it allows ready operation in a fail-safe manner (by virtue of the spring loading of the solenoid actuator) by an infirm person who would have difficulty in operating a more intricate control. In completed vehicles incorporating the chassis the actuator plate would be provided with a padded covering.

Figure 1 shows one version of a vehicle incorporating the chassis of the invention. The vehicle includes a canopy, shown in dotted lines, lights and a windscreen (not shown). The canopy defines a passenger cabin. Access to the passenger space is achieved e.g. by means of a zip- out, flexible door panel. The passenger seat and the upper end of the steering column are contained within the passenger cabin. Numerous other body styles may be devised. It is also possible to devise versions of the chassis which can be adapted to accommodate more than one passenger. The chassis 10 is particularly versatile because its overall length may be varied, by adjusting the length of the forward portion 11. Adjustment of the length in this manner automatically increases the distance of the handlebars 18 from the passenger seat support. This is particularly advantageous for the majority of potential passengers since those with longer legs are likely also to have longer arms and therefore require the handlebars to be placed further away from them in use of the chassis. However, the ability of the steering column 66 to pivot about a point (approximately one third of the way along its length in the embodiment described) allows the handlebars 18 to be brought closer to or further away from the position of any seat as desired, for instance as may be required when a passenger has long legs and short arms.

Claims

1. A chassis for a floor or ground engaging passenger vehicle comprising a forward portion; a rear portion securable to the forward portion; means secured to the forward portion for receiving a passenger support; floor or ground engaging means secured to at least one of the portions whereby a vehicle incorporating the chassis may travel over a floor or the ground; and a grippable means disposed in juxtaposition to the means for receiving a passenger support, wherein the forward portion includes a front sub-chassis and a further sub- chassis intermediate the front sub-chassis and the rear portion, the two sub-chassis being securable one to the other in a plurality of positions whereby the axial length of the forward portion may selectively be varied, the means for receiving a passenger support being secured to the intermediate sub-chassis and the grippable means being secured to the front sub-chassis.

2. A chassis according to Claim 1 wherein the position of the grippable means is adjustable relative to the front sub-chassis.

3. A chassis according to Claim 1 or Claim 2 wherein the front sub- chassis and the further sub-chassis include complementary, elongate, mutually engaging means securable one to another in a plurality of axial positions one relative to the other; and means for effecting said securing in a plurality of such positions.

4. A chassis according to Claim 3 wherein the front sub-chassis includes a rearwardly extending, elongate, open ended, hollow member and the intermediate sub-chassis includes a forwardly extending, elongate member, the forwardly extending member being slidably receivable in the hollow member via the open end thereof whereby the front and intermediate sub-chassis support one another in a desired relative axial position.

5. A chassis according to Claim 4 wherein the hollow member includes at least a first transverse aperture and the forwardly extending member includes a plurality of transverse apertures which may respectively be brought into register with the first aperture on axial sliding of the hollow and forwardly extending members one inside the other; and wherein the means for effecting securing includes a pin or bolt means releasably securable in the first aperture and one of the plurality of apertures in register therewith, thereby to lock the hollow and forwardly extending members in a desired relative axial position.

6. A chassis according to Claim 4 or Claim 5 wherein the hollow member extends horizontally, axially centrally along the front portion when the chassis is assembled; and wherein the forwardly extending member extends from the intermediate sub-chassis such that it is slidably receivable in the hollow member on assembly of the chassis.

7. A chassis according to Claim 6 wherein the hollow member includes secured thereto one or more laterally extending support members, whereby a portion of a vehicle body may be supported on the front sub-chassis.

8. A chassis according to Claim 6 or Claim 7 wherein the intermediate sub-chassis includes secured thereto one or more laterally extending support members, whereby a portion of a vehicle body may be supported on the intermediate sub-chassis.

9. A chassis according to any preceding claim, wherein the forward portion includes a locating member projecting therefrom and the rear portion includes a seating adapted to receive the locating member, whereby the intermediate sub-chassis and the rear portion may be coupled together such that relative axial movement therebetween is prevented.

10. A chassis according to Claim 9 wherein the locating member and the seating therefor are such that, when the intermediate sub-chassis and the rear portion are coupled together, relative rotational movement therebetween about an axis, which when the chassis is assembled is vertically perpendicular to the longitudinal axis of the chassis, is prevented.

11. A chassis according to Claim 9 or Claim 10 wherein the locating member comprises a generally horizontal bar projecting from the forward portion, and the seating comprises at least one cup adapted to receive the bar in such a way that movement of the bar relative to the cup in a direction transverse thereto is prevented.

12. A chassis according to Claim 11 wherein the cup includes a member extending to cover a portion of the opening thereinto, the bar being shaped so that it may only be inserted into the cup past said member in a limited range of orientations.

13. A chassis according to Claim 12 wherein the cup is shaped to allow the bar to adopt an orientation outside said range once the bar has passed said member.

14. A chassis according to any of Claims 11 to 13 including a plurality of said cups.

15. A chassis according to any of Claims 9 to 14, wherein the intermediate sub-chassis includes extending upwardly therefrom a first bracing member and the rear portion includes extending upwardly therefrom a second bracing member, said bracing members being disposed such that, on locating of the locating member in the seating a portion of the first bracing member remote from the intermediate sub-chassis is disposed proximate a portion of the second bracing member remote from the rear portion, means being provided for securing the bracing members one to the other in the region of their mutual proximity.

16. A chassis according to Claim 15 wherein the first bracing member is constituted as the means for receiving a passenger support.

17. A chassis according to any preceding claim wherein the floor or ground engaging means includes a plurality of wheels rotatably secured thereto to support the chassis on a surface and permit travel of the chassis thereon.

18. A chassis according to Claim 17 wherein the rear portion thereof includes a pair of wheels rotatably secured thereto and interconnected by an axle.

19. A chassis according to Claim 18 wherein the axle includes first and second portions drivingly interconnected by a clutch means, whereby slipping of the clutch means occurs when the torques acting on the respective wheels differ by more than a predetermined amount.

20. A chassis according to Claim 17 or Claim 18 wherein the forward portion thereof includes at least one wheel rotatably secured thereto.

21. A chassis according to Claim 20 wherein said wheel is steerable.

22. A chassis according to Claim 21 wherein the forward portion includes a pair of steerable wheels rotatably secured thereto; and a steering mechanism.

23. A chassis according to Claim 22 wherein the steering mechanism includes a steering column.

24. A chassis according to Claim 23 wherein the steering column includes a lower part operatively connected to the steerable wheels via a plurality of link means and an upper part pivotably secured to the lower part.

25. A chassis according to Claim 24 wherein the grippable means is constituted as a handlebar or pair of handlebars secured to said upper part.

26. A chassis according to any preceding claim wherein the rear portion includes a motor means and a drive transmission means whereby the output of the motor means may cause driving motion of the floor or ground engaging means.

27. A vehicle including a chassis according to any preceding claim.

28. A vehicle according to Claim 27 including a passenger seat received in the passenger support receiving means.

29. A vehicle according to Claim 27 or Claim 28 including a floor or other body part supported on the laterally extending member or members of the front sub-chassis and/or of the intermediate sub-chassis.

30. A vehicle according to any of Claims 27 to 29 including a cabin having an entry/exit aperture for a passenger; the chassis, the aperture and the cabin being dimensioned to permit ready entry into and exit from the cabin by a disabled or infirm passenger.

31. A kit of parts for the assembly of a chassis comprising a front sub-chassis; an intermediate sub-chassis, the two sub-chassis being securable together in a plurality of relative positions to form a forward chassis portion of adjustable length; and a rear chassis portion securable to the intermediate sub-chassis, at least one of the front and rear chassis portions having secured thereto a floor or ground engaging means; the front sub-chassis having secured thereto a grippable means; and the intermediate sub-chassis having secured thereto means for receiving a passenger support.