GB2131362A - Vehicle with pivotless wheels - Google Patents

Abstract

The vehicle, which may be used as an all-weather sledge, has a platform 10 supported relatively rotatably one or more pivotless wheels 11. Each wheel 11 may engage an arcuate channel in guide means 14 fixed to the platform 10 (as shown) or, in a modification the guide means may engage a channel in the periphery of the wheel. The guide surface may extend throughout the inner periphery of the wheel. Contact between each wheel 11 and the guide means is preferably purely frictional, the wheels being held upright by the weight of the platforms 10 and a load thereon, such as a rider lying face down and gripping the bar 17 on top of the platform. Ground engaging ribs 18 for braking (or, in a modification, wheels) may be provided under the platform. The wheels 11 are demountable simply by lifting the platform 10. A motorised mountain rescue vehicle is disclosed with pivotless wheels capable of oscillating about eccentric axes. <IMAGE>

Description

SPECIFICATION Vehicle This invention relates to a vehicle.

According to the invention a vehicle comprises at least one pivotless wheel, a load-bearing part and between the wheel and the load-bearing part and secured to the latter curved guide means of similar radius of curvature to the wheel and adapted to engage the wheel over at least part of the circumference of the wheel, the guide means serving, in use, to restrict relative axial displacement of the wheel while permitting rotation of the wheel.

Preferred embodiments of the invention will now be described with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a perspective view of a sledge-like vehicle, Figure 2 is a sectional elevation taken on the line Il-Il of Figure 1, Figure 3 is a detail view on an enlarged scale taken on the line Ill-Ill of Figure 2, Figure 4 is a side elevation of a second embodiment of the invention, Figure 5 is a sectional elevation taken on the line V-V of Figure 4, Figure 6 is a view similar to Figure 5 of a modification, Figure 7 is a detail view on an enlarged scale illustrating a different way in which the carriage of the embodiment of Figures 1-3 or 4 and 5 or 6 may engage one of the wheels, or its wheel, Figure 8 is a side elevation and Figure 9 is a rear view of a multi-wheel vehicle, Figure 10 is a view on an enlarged scale of one of the wheels of the vehicle of Figures 8 and 9, Figure 11 is a detail on an enlarged scale illustrating the connection between one of the wheels of the vehicle of Figures 8-10 and the load-bearing platform thereof, Figure 12 is a side view of another embodiment of the invention, Figure 1 3 is a cross-sectional view on an enlarged scale taken on the line Xlll-Xlll of Figure 12, Figure 14 is a view similar to Figure 13 but illustrating a modification, and Figures 1 5 and 1 6 are respectively a side elevation and a plan view of yet another embodiment of the invention.

In the embodiment of the invention iliustrated in Figures 1-3 the platform 10 of a sledge-like vehicle is, in use, supported on two wheels 11 which are in the form of simple hoops or spokeless felloes. The wheels 11 are readily demountable from the platform 10, e.g. for transport or storage, by lifting the platform so that the wheels emerge from respective arcuate channels 12 in which, in use, they are held upright by the weight of the platform and any load thereon.Each of the arcuate channels 12 is provided by the assembly of a segmental inner element 13 and two larger, outer segmental elements 14 and 1 5 held together by bolts 16, each such assembly being integral with a respective side of the platform 10 so that the U-section, arcuate channel 12, which is of similar radius of curvature to the associated wheel 11, opens downwardly of the platform. As will be apparent from Figure 3, the dimensions of the outer elements 14 and 1 5 of each guide channel are greater than those of the inner element 13 sandwiched between them but not as great as the associated wheel 11 so that, in use, each wheel 11 extends out of its channel 1 2 sufficiently to support the assembly above the ground and to be the first component to encounter a gradient or obstruction when the vehicle is moving.On the other hand the pivotless wheels 11 are held in the upright positions shown in Figure 1, and maintained in such positions while the vehicle is moving, solely by the downward pressure exerted by the channels 1 2 due to the weight of the platform 10 and any load (such as a passenger) on it.

In the embodiment illustrated the wheels 11 have no bearings and are in frictional contact with the channels 1 2. Friction can be reduced in any known suitable manner, such as the use of suitable lubricants or anti-friction materials for the rubbing surfaces. If the wheels and channels are of wood the wood may be waxed. Alternatively they may be of, or may be lined with, polypropylene or another suitable plastics material.

The platform 10 has an upper transverse rib 1 7 serving as a hand-hold for someone lying face down upon it and two lower transverse ribs 1 8 which are of rounded cross-section and each of which will serve as a brake when it encounters the ground.

One of the uses for the vehicle of Figures 1-3 which is envisaged is as a substitute for a sledge when ground conditions are such that a sledge would not slide well on conventional runners but equally a conventional wheeled vehicle would not perform well or would be unsafe. Sledges are relatively safe (as well as cheap and simple) vehicles because of the very low centre of gravity, but in climates such as ours they are rarely useable. The present invention provides a sledgelike vehicle which has the advantage of a wheeled vehicle that it can be used all the year round but avoids the drawbacks of a wheeled vehicle in that although the wheels are large enough to move easily over rough terrain and obstacles nevertheless the centre of gravity of the rider is very close to the ground.In addition the vehicle is of very simple, robust construction and the weaknesses of conventional wheeled vehicles represented by the wheel bearings are obviated.

Since the wheels 11 are simple rings and are not attached to the carriage represented by the platform 10 and guide channels 12 they can be used separately as toys.

A model of the Figures 1-3 embodiment which has performed well was made in wood with a platform 7620 mm long by 6096 mm wide and wheels 12192 mm in diameter and 381 mm in rim thickness.

It will be apparent that, optionally, ball-needleroller or other known suitable bearings may be located in the channels 1 2 to assist rotation of the wheels 11, in use, but it is not envisaged that these would be either necessary or desirable in the case of a sledge-like vehicle intended for leisure use, where cheapness and a robust construction are prime desiderata as well as the avoidance of jamming which might occur if mud and the like were to enter the channels. The vehicle performs well on wet grass and is not intended to be useable only or even primarily on hard surfaces such as roads.

The embodiment of Figures 4 and 5 may be regarded as a mono-cycle variant of the preceding embodiment, and like parts have been given like references. The platform 10 and one of the wheels 11 are dispensed with and the rider is supported directly on the segmental guide assembly 13, 14, 1 5 providing the arcuate channel 12 in which the single wheel 11 is located. The rider is shown grasping a handlebar 1 9 upstanding from the carriage assembly 13, 14, 15 and he is using the mono-cycle like a child's scooter.

Figure 6 illustrates how, if the single wheel 11 of the mono-cycle is of substantial width and would tend to obstruct the rider's view riders may be supported on projections 1 4a and 1 5a of the carriage which extend axially outward of the wheel 11 so that the riders have a clear view.

Figure 7 illustrates how in the embodiments of Figures 1-3,4 and 5 or 6, the inverted, arcuate channel 12 may be dispensed with and instead the or each wheel 11 A may be formed or provided in its inner periphery with an annular, circumferential groove 12A. An element 1 3A which extends downward from the platform 10, or which directly supports the rider or riders, has an arcuate lower edge of the same radius of curvature as the bottom of the groove 1 2A and, in use, rests therein so that relative rotation of the wheel I 1A is permitted but relative axial displacement of the wheel 11 A is restricted by the side walls of the groove 12A.

Figures 8-11 illustrate a multi-wheel embodiment of the invention in which a common platform 1 OB is supported by three pairs of transversely spaced wheels 11 B. Each of these has on opposite sides and at diametrically opposite positions cheek plates 1 4B and 15B connected by integral webs 20, the cheek plates 1 4B and 15B having arcuate outer edges which overlap opposite sides of the associated wheel 11 B to serve the same purpose as the elements 14 and 1 5 in Figures 1-3. Within each wheel 11 B there is a roller 21 which is rotatable on an axle 22 (see Figure 11) journalled to the platform 1 or. In the case of each wheel assembly the axle 22 passes through a hole 23 in the lower, inner cheek plate 1 5B and the entrapment of the relatively greater diameter roller 21 between the lower cheek plates 1 4B and 15B prevents separation of the wheel 11 B and platform 1 OB axially of the wheel.

if the vehicle is to be self-propelled any one or more of the rollers 21 may be rotatable, through a suitable gear train, by a prime mover 24 mounted on the platform 1 OB. Contact between a driven roller 21 and the inner periphery of the associated wheel 11 B may be simply frictional or the roller and the inner periphery of the wheel may be formed or provided with meshing gear teeth.

The vehicle of Figures 8-11 1 combines the advantages of a Icw-slung carriage 1 OB with large-diameter, pivotless wheels 11 B. The wheels will be able to negotiate rough terrain and obstacles without tipping a load off the platform 1 OB. Among the uses envisaged for the vehicle is mountain rescue, where the injured person must be kept safe and steady while the "stretcher" vehicle negotiates rough ground and a variety of surfaces. In the case of a motorised vehicle the rollers 21 will provide a low gear ratio drive, but in the use mentioned good climbing ability and good control in descent will be far more important than high speed.

Another feature of this embodiment of the invention is that the wheel assemblies 11 B, 1 4B, 15B, 20 are capable of rotary movement relative to the platform 1 0B about the eccentric axes of the rollers 21 (one of these axes is indicated at X-X in Figure 11). Individual wheels 11 B can thus "oscillate" to accommodate uneven terrain, and if a wheel 11 B is arrested by an obstacle the associated roller (or drive pinion) will tend to climb the leading side of the wheel until the resulting imbalance causes the wheel to roll forward.

The embodiment of the invention illustrated in Figures 12 and 1 3 differs from those previously described in that the guide means 25 whereby the wheel 11 C is rotatable but not axially displaceable relative to the load-bearing part 1 0C extends throughout the inner circumference of the wheel 11 C instead of being arcuate and subtending an angle of less than 180 . The channel extending over the whole width of the wheel is replaced by one which extends only over a central, annular rib on the inner periphery of the wheel 11 C but it will readily be appreciated that this arrangement could be reversed, i.e. that the carriage 1 0C could have an annular rib engaged in an annular channel in the inner periphery of the wheel. The location of the wheel 11 C relative to the carriage 1 0C may be effected by more than one interfitting annular rib and groove.

In the example of Figures 12 and 13 two rings 25a and 25b fixed in axially spaced relation to the carriage 1 0C define between them an annular groove 25c in which there is located an annular rib 26 fixed relative to the inner periphery of the wheel 11 C.

It will be appreciated that the wheel 11 C may be that of a mono-cycle or that the carriage 1 0C may be integral with others in a multi-wheel vehicle.

Figure 14 is a view similar to Figure 13 of yet another embodiment of the invention, in which a wheel 11 D is fitted on its outer periphery with a solid or pneumatic tyre 27. In this embodiment the rubbing surfaces 28, 29 between a load-bearing part 1 0D and the inner periphery of the wheel 11 D are plain cylinders and relative axial displacement is prevented not by a channel or a rib-and-groove formation but by two annular flanges 1 4D and 1 5D fixed to opposite sides of the wheel 11 D so as to extend therefrom both radially inwardly and radially outwardly. The flanges 1 4D and 15D serve to prevent relative axial displacement both between the wheel 11 D and the load-carrying part 1 OD and between the wheel 11 D and the tyre 27.

It will be appreciated that the flanges 1 4D and 15D need not be annular. A series of circumferentially-spaced, arcuate flanges would serve the same purpose.

Figures 15 and 1 6 illustrate yet another embodiment of the invention in which the guide means permitting rotation of a wheel 11 E relative to a load-carrying part 1 OE while restricting their relative displacement axially of the wheel comprises members 28 on opposite sides of the wheel 11 E, the members 28 being integral with the load-carrying, segmentally shaped part 1 OE and extending beyond the wheel 11 E in both the forward and backward directions. In the example shown auxiliary, freely rotatable wheels 29 are mounted on the ends of the members 28. In a mono-cycle construction these would prevent violent braking and would rotatably support the assembly if ends of the members 28 on the same side of the wheel 11 E touched the ground, but in a multi-wheel assembly in which the wheel 11 E is one of a number supporting the same load carrying part 1 OE the members 28 may be common to all the wheels on the same side of a platform (not shown) integral with the part 1 OE and the auxiliary wheels 29 may be dispensed with.

Claims (14)

1. A vehicle comprising at least one pivotless wheel, a load-bearing part and between the wheel and the load-bearing part and secured to the latter curved guide means of similar radius of curvature to the wheel and adapted to engage the wheel over at least part of the circumference of the wheel, the guide means serving, in use, to restrict relative axial displacement of the wheel while permitting rotation of the wheel.

2. A vehicle as claimed in Claim 1, wherein the inner periphery of the wheel is in direct, frictional contact with the guide means.

3. A vehicle as claimed in Claim 2, wherein the wheel and guide means have rubbing surfaces treated or composed of material to reduce friction.

4. A vehicle as claimed in any one of the preceding claims, wherein the guide means is arcuate, the arc subtending an angle of less than 1800.

5. A vehicle as claimed in Claim 4, wherein the wheel is removable from the guide means by lifting the latter clear of the wheel and the wheel is held upright, in use, by the weight of the loadbearing part and any load thereon.

6. A vehicle as claimed in any one of Claims 1 to 3, wherein the guide means subtends an angle of more than 1 800 and the wheel is captive thereon.

7. A vehicle as claimed in any one of the preceding claims, wherein the guide means is of channel section.

8. A vehicle as claimed in any one of the preceding claims, wherein the load-bearing part has a load-bearing, upper surface which is below the centre of rotation of the wheel.

9. A vehicle as claimed in any one of the preceding claims, comprising similar guide means adapted to engage similar pivotless wheels in spaced relation transversely and/or longitudinally of the load-bearing part.

10. A vehicle as claimed in Claim 9, wherein the load-bearing part is a platform located between and extending, in use, longitudinally beyond one or more pairs of transversely spaced pivotless wheels.

11. A vehicle as claimed in any one of Claims 1 to 10, and further comprising a roller rotatable relative to the load-bearing part and in engagement with the inner periphery of the or at least one of said pivotless wheel or wheels.

12. A vehicle as claimed in Claim 11, wherein said roller is a driven member and it and the inner periphery of the pivotless wheel engaged thereby are formed or provided with meshing gear teeth.

13. A vehicle as claimed in Claim 11 or Claim 12, wherein the guide means has an aperture through which an axle of the roller extends from the load-bearing part to engage the pivotless wheel.

14. A vehicle as claimed in any one of Claims 11 to 13, wherein the guide means is pivotably secured to the load-bearing part so as to be relatively rotatable about the rotational axis of said roller.

1 5. A vehicle substantially as described in the Description, with reference to and as shown in Figures 1 to 3, Figures 4 and 5, Figure 6, Figure 7, Figures 8 to 11, Figures 12 and 13, Figure 14 or Figures 1 5 and 16 of the accompanying diagrammatic drawings.