CA1143763A - Adjustable axle assembly to alter wheel base & track - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
There is described a telescopic axle assembly for use on vehicles, the assembly comprising, when viewed in plan, a V-shaped axle housing, the arms of the V projecting rearwardly of the vehicle, and axle members adjustably received into the axle housing to be e tensible and retractable relative to the housing to both lengthen the wheel base and widen the track of the vehicle.

Description

3'7~3~

This is a divisional application of Canadian Patent Application Serial No. 364,]94 filed November 6, 1980.
The present invention relates -to improvements to motorized vehicles and finds particular application on those types of vehicles, such as electric wheelchairs, employed by the handicapped to provide added mobility.
It will be appreciated that although the description of the invention that follows hereinafter is made with reference to electrified wheelchairs, the invention finds application on all manner of motorized carts such as may be found in the work-place, on the golf course, and so on.
Motorized wheelchairs of the same general configuration as described and illustrated herein are known. Such wheelchairs, however, possess a number of disadvantages in their construction and operation which pose substantial difficulties for their users. Some units can be disassembled only to a limited extent, such as by removing the chair portion from the motorized platform.
The platform, comprising the unit's suspension, batteries, motors and drive train, is usually far too heavy and bulky to be wielded by the actual user, requiring that an attendant be on hand to assist in loading the wheelchair into an automobile for transport or to remove it up a flight of stairs, for instance. Other units can be broken down into a greater number of parts although the disassembly procedure requires that the operator bend at the knees and perform a number of operations requiring a high degree of manual dexterity. Again, such actions are often beyond the capabilities of the user. It will be appreciated that similar difficulties are encountered when the wheelchair is to be reassembled.
Other disadvantages encountered with known motorized wheelchairs occur with respect to difficult-to-operate seat clamping and braking mechanisms.
' ~

'763 Further, because these vehlcles by their very nature possess a relatively high centre of gravity, grades and inclines beyond a predetermined threshold cannot be traversed with safety. The attempted solution to this problem on known vehicles has been to provide add-on items including additional axles and wheels to widen the stance or track of the wheelchair.
Such add-on apparatus has been proven awkward and cumbersome to install and use, requiring the use of special tools such as retaining ring pliers and once again necessitating a degree of physical dexterity often not possessed by the handicapped user. The attempted solutions have moreover been deficient in not providing a means to concurrently lengthen the wheelbase of the chair.
Accordingly, it is an object of the present invention to provide an improved electrified vehicle which obviates and mitigates from the disadvantages of prior art wheelchairs.
According to the present invention, then, there is provided a telescopic axle assembly for use on lightweight vehicles, the axle assembly comprising a V-shaped axle housing disposed proximal the rearward end of the vehicle, the arms of the V extending rearwardly towards the rearward end; and an axle member having a vehicle supporting wheel rotatably affixed to the outer end thereof adjustably received within each of the rearwardly projecting arms, each of the axle members being selec-tively adjustable within the arms between a fully retracted and a fully extended position to simultaneously vary the wheel base and the track of the cart.
Embodiments of the present invention, as well as that described in Application No~ 364,194 will now be described in greater detail and will be better understood when read in conjunction with the following drawings in which:

Figure 1 is a perspective view of a motorized wheel-chair as described herein;
Figure 2 is a rear perspective view of the connecting assembly for use on the wheel chair of Figure l;
Figure 3 is a side elevational, partly sectional view of the connecting assembly of Figure 2;
Figure 4 is a side elevational, partially sectional view of the connecting mechanism of Figure 3 in the engaged position thereof;
Figures 5 to 9 are side elevational, partially sect sectional views showing the assembly and disassembly of the connecting mechanism of Figures 2 to 4;
Figure lO is a side elevational view of the seat clamping mechanism described herein;
Figure 11 is a plan view of the seat clamping mechanism : of Figure 10;
Figure 12 is a bottom plane, partially sectional, view of the frame of the wheelchair of Figure l;
Figure 13 is a front elevational view of a rear brake 3'~63 assembly for use on the wheelchalr of Figure l;
Figure 14 is a side elevational, partially sectional view of the power head of the wheelchair of Figure l; and Figure 15 is a front elevational view of the power head of Figure 14.
Referring now to Figure 1, there is shown generally a motorized wheelchair comprising a detachable front end assembly including power head 2, connecting mechanism 8 and steering column 61 with handle bars attached, a base or platform 3, a detachable swivel seat 4 and batteries 5.
Connecting the front end assembly to platform 3 is a connecting mechanism 8 as shown in Figures 2 and 3. The connect-ing mechanism consists primarily of a hook assembly 9 and a latch portion 11. Latch portion 11 is fixedly attached to the wheelchair frame 16, details of which will be provided below.
With specific reference now to Figures 2 and 3, hook assembly 9 consists of a tubular sleeve 17 having nylon bushings 18 fitted into each end thereof. Affixed to opposite sides of sleeves 17, such as by welding, are hook plates 20 arranged tangentially to sleeve 17. Extending between plates 20 and connected thereto is a lateral plate 42 which extends vertically from the bottom of plates 20 upwardly to a point just opposite hooks 23. Plate 42 may be tangential to sleeve 17. Each hook plate is formed having an engaging hook 23 and a support hook 25 extending in one direction and a flange 27 projecting in the opposite direction. Plates 20 are arranged to parallel one another so that the said hook and flange members formed thereon are aligned with one another.
Engaging hooks 23 are each formed to have a clearance radius 43 and a recess 44 formed proximal to the lowermost ends of the hooks. Recess 44 is defined by an upper shoulder 45 and an engaging surface 47, the function of which will be described below. Apertures 48 are formed into hooks 23. When the hook assembly is mated with latch assembly 11, apertures 48 align with apertures 49 formed into retaining plates 76 which form part of the latch assembly. A retractable pin may be inserted into the apertures to ensure the continuous engagement of the hook assembly to the latch assembly.
Supporting hooks 25 are formed about the lower ends of hook plates 20. Radius 53 is intended to receive and support tubular frame member 67 when the hook and latch assemblies are engaged. Accordingly, the diameter of the support hook is just slightly in excess of that of frame member 67. Curved arm 54 of hook 25 extends upwardly to envelope slightly more than half of frame member 67.
Projecting in the direction opposite hooks 25 are flanges 27. Axially aligned holes are formed in the flange to receive a hinge pin 31 about which handle 32 is rotatably mounted. Stops 35 project outwardly from the flanges to engage shoulder portions 57 of handle 32, limiting the rotational move-ment of the handle in the counter clo~kwise direction. Stop 35 engages handle arm 58 to limit the clockwise rotational movement of the handle. Handle 32 further includes lower levers 60 which project towards latch portion 11. It will be seen from the drawings that the handle is mounted so that the lower portions thereof, including arms 60, bracket the lower portions of hook plates 20. The handle is retained about hinge pin 31 by means of circlips 33 or by any other suitable means of attachment.
The hook assembly as described above is mounted on power head 2 as follows. Fixedly connected to the power head and 3'763 projecting upwardly therefrom is a tubular core 1~. A spacer 13 is fitted over core 12 to rest against plate 71 fixedly connected to the cowling 72 of the power head. Tubular core 12 is connect-ed at its lower end to plate 71 by welding or it may be integrally formed therewith. Hook assembly 9 is then fitted over core 12 to rest against spacer :L3. The hook assembly is oriented so that handle 32 projects forwardly of the wheelchair. Lastly, a retaining sleeve 14 is fitted over the core. A set screw 15 is provided to connect sleeve 14 to tubular core 12. It will be appreciated that nylon bushings 18 facilitate the rotational movement of sleeves 13 and 14 and core 12 relative to hook assembly 9.
To complete the front end assembly, steering column 61 is received into core 12 to be held in place therein by means of release pin 62. Rotational movements imparted to the steering column are transmitted to core 12 and hence to power head 2 itself by means of tabs 63 formed onto the steering column which engage notches 70 formed into tubular core 12.
Turning now to latch assembly 11, the assembly includes a plate 75 rigidly affixed to tubular frame member 67.
Affixed to the sides of plate 75 to be flush mounted with rear surfact 78 therèof are retaining plates 76. Plates 76 are disposed in parallel alignment. Plate 75 is of a width such that plates 76 are spaced sufficiently far apart to receive hook plates 20 therebetween when the connecting mechanism is in the engaged position. The inner leading edges of retaining plates 76 are beveled to facilitate the entry of hook assembly 9 between the plates. Plate 75 extends vertically from the bottom of retaining plates 76 to a point approximately opposite the lowermost extend of engaging surface 47 on engaging hook 23.

'63 The uppermost portion of the plate is rounded as shown at 77 in the drawings. Formed into rear surface 78 of plate 75 is a horizontally extending notch 79 of rectangular cross-sectional configuration. Slots 80 are formed into plate 75 adjacent retaining plates 76 to allow for the passage of support hooks 25 therethrough.
The portions of frame member 67 aligned with slots 80 are notched to form colinear slots 8~.
Referring now to i`igs. 2 ~nd 4 showin~ hoQk asse~bly 9 in engagement with latch assembly 11, it will be seen tha-t ln the engaged position hook assembly 9 is received between retaining plates 76 and tubular frame member 67 is received into and is supported by hook 25 with arms 54 of the hook wrapping around tubular frame member 67 to prevent disengagement under load conditions. It will be appreciated that under load, the down-wardly directed component of the load forces will tend to cause an outward splaying of the power head and steering column assembly away from base 3 of the wheelchair. This tendency is resisted by the extent of curvature of arms 54 about tube 67 and also by the reactive forces between plates 42 and 75 which are brought into contact by the engagemen~ by the hook and latch assemblies. In other words, the cradling of tube 67 within hook 25 maintains hook assembly 9 in engagement with latch assembly 11 whereas the contact between the plates 42 and 75 prevents rotational movement of the hook assembly about tube 67.
Further, the contact between plates 42 and 75 ensures proper upright alignment of the front end assembly relative to the remainder of the wheelchair.
Also in the engaged position, the upper surfaces of release levers 60 res-t in close proximity to the lower surfaces 3'763 of retaining plates 76, it being appreciated that the distance between release levers 60 is substantially equal to the dis-tance between retaining plates 76.
In ~he engaged position, hook assembly 9 is held stationary between plates 76. Steering column 61 and tubular core 12 rotate within sleeve 17 to effec-t the steering movements of power head 2. As previously mentioned, retaining sleeve 14 is connected to the steering column by means of a set screw 15 so that sleeve 14 rotates relatlve to assembly 9. The extent of rotation of sleeve 14 and hence that of column 61 is therefore limited due to contact between set screw 15 and hook plates 20, thereby preventing the inadvertent over-rotation of the power head which could cause an upset of the wheelchair.
Referring now to FigS. 4, 5 and 7, to disassemble the front end assembly from the remainder of the wheelchair, it is necessary to merely depress handle 32 in the direction indi-cated by Arrow A in Figure 5. The handle pivots about hinge 31 so that release lever 60 acts to boost retaining plates 76, and thus the frame of the wheelchair to which they are attached, upwardly, causing tubular frame member 67 to disengage from support hook 25. As frame member 67 disengages from the support hook, the power head begins to splay outwardly from platform 3, pivoting about the rounded portion 41 of plate 42. As disengage-ment continues, curved arm 54 of hook 25 inscribes a path about the bo-ttom of tubular member 67 until it passes the midway point thereof and member 67 beings to slide downwardly past curved arm 54. As it does so, curved arm 54 passes through notches 80 and 81 formed into plate 75 and member 67 respectively to thereby facilitate a smooth disassembly movement. As the process continues, plate 75 passes downwardly relative to plate 42 so ~3'7~3 that the outwards splaying of the power head continues about the rounded portion 77 of plate 75. When platform 3 comes to rest on the ground, disassembly is complete. Retaining plates 76 continue -to bracket hook assembly 9 so that the front end assembly as a whole does not fall off to either side and so that the steering column continues to project upwardly and rearwardly where it may be easily grasped. To remove the fron-t end assembly including the power head, the user need only lift the assembly using handle 32 or the steering column, whereupon the power head comes completely away for easy transport. Alterna-tively, the front end assembly may be pushed forwardly relative to the remainder of the wheelchair to thereby effect its removal without the need for lifting. It will be appreciated that the whole disassembly procedure requires only a second or two of time and a minimum amount of exertion by the operator who need only bend at -the waist to depress handle 32 to initi~te the disassembly procedure.
To reassemble the front end assembly to the platform, reference is made to the procedure illustrated in Figure s 7, 8 and 9. The hook assembly 9 is first guided between retaining plates 76 so that steerinq column 61 is inclined towards the rear of the wheelchair. By giving a little push to the steering column in a direction substantially parallel to the longitudinal axis thereof, engaging surface 47 of engagement hook 23 enters notch 79 formed into the rear surface 78 of plate 75. Steering column 61 is then rotated in the direction indicated by arrow F so that engagement surface 47 engages the uppermost surface of notch 79 as shown. As the steering column continues to be righted, pla.form 3 is lifted off the ground and is drawn towards the power head. As the rotation of the steering column continues, 3'7~3 shoulder 45 of hook 23 contacts rear surface 78 of plate 75 and begins to lever engagement surface 47 out of notch 79. This disengagement process continues even as tubular member 67 is drawn into a pOSitiOII over support hook 25. Finally, surface 47 is levered completely out of contact with notch 79 and the platform drops, whereupon tubular member 67 is caught by support hooks 25 to be cradled therein. Assembly is now complete.
Again, the entire process requires only seconds of time and the operator need hardly even bend at the waist. As discussed above, the hook and latch assemblies are now completely self secured and in a condition to be loaded. As a safety precaution, however, a retractable pin may be inserted through apertures 48 and 49 formed into hook and retaining plates 20 and 76, res-pectively.
It will be appreciated that although the present connecting mechanism has been described in the context of an electric wheelchair in view of its obvious advantages to the handicapped or partially handicapped person, the connecting mechanism will find application on all manner of carts or motor-ized vehicles which are amenable to disassembly.
To lend added utility to a wheelchair of the typereferred to herein, it has proven useful to provide a seat which swivels. This provides for easier ingress and egress of the user and also allows the operator to draw up along side a desk or work surface and pivot his feet underneath. Many other advantages accrue as are well known in the art. For safety reasons, however, it has been found desirable to provide a seat clamping mechanism to prevent rotation of the seat particularly when the wheel chair is being driven. The disadvantages of known clamps are that the clamp lever, the operating handle or knob of which 11~3'7~

is typically located beneath or beside the seat, must be moved laterally in a direction substantially parallel to the ground.
Given the forces re~uired to do so, many handicapped persons find it most difficult to genera-te the necessary strength to eause this lateral motion. Such persons, however, have little or no difficulty in generating sufficient force with which to depress a clamping lever, particularly as body weight can be brought to bear for this purpose.
Referring now to Figures 10 and ll, there is illustrat-ed therein an improved clamping mechanism 90 operable by reans of a lever 91 actuatable in the vertical plane to facilitate its use.
Clamp 90 is mounted about seat column 92. Column 92 is in turn received into a tubular sleeve 93 which is fixedly connected to platform 3 and projects upwardly therefrom. Fitted about the lower end of column 92 is a nylon bushing 94 which is slidably and rotatably received into sleeve 93.
The clamp itself includes a collar 96 fastened about column 92 by means of a set screw 97. As the position of the collar 96 determines the actual height of the swivel seat, a number of holes may be provided up and down the column to receive the set screw. Depending downwaxdly from collar 96 is a conneetor 98 to the lower end of which is connected clamp bloek 100 whieh encircles, apart from gap 101, seat column 92.
The clamp block is generally rectangular in external configuration and has formed therein an opening 102 (shown in phantom lines in Figure 10) of a diameter slightly larger than that of tubular sleeve 93. Opening 102 may flare outwardly as shown in the Figure to facilitate the entry of sleeve 93 into the opening.
A nylon bushing 104 is a slidably provided between clamp block 100 and seat column 92.

3~3 When it is desired to install the swivel seat, column 92 is guided into sleeve 93 and lowered thereinto. As the collar is dropped further into the sleeve, the leading or upper end of the sleeve enters opening 102 and envelopes the lower portion of bushing 104. The sleeve comes to rest again~t the flanged portion of bushing 104 which acts as a bearing between the sleeve and collar 96 to facilitate the swiveling motion of the seat.
The clamp actuating mechanism includes lever 91 which is fixedly connected to a spacer 105. Spacer 105 extends down-wardly and receives through its lower end set screw 106. Set screw 106 extends into a cavity 107 formed into the side of lobe 113 of clamp block 100~ On the opposite side of clamp block 100 another spacer 109 is fixedly connected to lever 91. Spacer 109 is pivotally connected at its lower end to one end of pivot bars 110. The other ends of the pivot bars are pivotally connected to a projection 111 formed integrally onto lobe 114 of clamp block 100.
In the unclamped position, as shown by solid lines, pivot rods 110 project upwardly at an acute angle to column 92 whereas set screw 106 projects slightly downwardly to define an acute angle with sleeve 93.
As lever 91 is depressed, rods 110 assume a more hori-zontal position as does set screw 106. The resulting convergence of rods 110 and set screw 106 compresses clamp block 100 and more particularly causes a narrowing of gap 101. A clamping force is thereby exerted upon nonrotatable sleeve 93. It will be appreciated that clamp block 100 is anchored to collar 96 which is fixed.ly connected to column 92. Further rotation of seat column 92 is thus by prevented. It will be further apprecia-ted ~3'7~;3 that as lobe 113 is held stationary by connector 98, it is lobe 114 which moves inwardly in response to the depression of clamp lever 91. The downward extent of travel or lever 91 is limited by contact between the lever and the outer corner of projection 111. In this regard, set screw 106 is adjusted so that lever 91 tends to snap into the clamped position as it makes contact with projection 111.
To release the clamp, it is merely necessary to pull upwardly on lever 91. A ball knob may be fitted to the end of the lever to facilitate its operation.
An alternative clamp configuration may be as follows.
Set screw 106 may be eliminated in favour of a bracket (not shown) affixed to lobe 113 of clamp block lOO to project upwardly therefrom. The end of lever 91 is pivotally received into the bracket. Lever 91 is connected to pivot rods 110 in the manner shown in Figure 10. Accordingly, by depressing lever 91, rods 110 are pivoted into a more nearly horizontal position, causing movement of lobe 114 towards lobe 113 which is held stationary by connector 98.
Referring now to Figure 12, there is shown in plan view wheel chair frame 16, including V-shaped telescopic rear axle 120. The frame also includes tubular member 67 which co-operates with and forms a part of latch assembly 11 and member 121 which runs along the length of platform 3. Frame member 121 is bent upwardly to conform to the shape of running board 6 (Figure 1). The frame may be glued to the platform or affixed thereto by any other suitable means.
As mentioned previously, wheelchairs of the type described herein typically possess a high centre of gravity and suffer a further instability by virtue of the concentration of ~ ~3'~63 so much weight over the rear axle, including the weight of the operator. It will be appreciated, therefore, that great care must be taken to avoid :inclines beyond a threshold grade lest the wheelchair begin -to tip over rearwardly. Similar problems are encountered when the direction of travel is normal to the grade, the tendency then being to tip over sideways. To over-come the latter problem, known wheelchairs have offered outriding bogey wheels and an additional axle or axle extensions to support them. The problem with such accessories lies in the inconvenience of their installation as well as problems of transporting and storing these accessories when not in use. No solutions have been offered which overcome the problem of rear-ward instability.
Referring once more to Figure 12, both problems have been overcome by providing a telescopic rear axle assembly 120 which radiates outwardly and rearwardly from a hub 127 Fixed axle housings 122 are securely fastened to the frame whereas adjustable axles 124 are slidably received within housings 122.
Wheels 125 are mounted about the outer ends of axles 124 in any known fashion. Adjustable axles 124 are held in position by means of removable pins 126. A plurality of pairs of axially aligned apertures 128 are formed in axles 124. Apertures 128 may be brought into alignment with axially aligned apertures 129 formed into housings 122, thereby providing adjustability to the degree of extension of axles 124. It will be appreciated, of course, that the extension of axles 124 results not only in a widening of the wheelchair's track but also in a lengthening of its wheelbase, adding greatly to the chair's stability without the necessity for becoming involved in the handling of oiled parts or special tools~

~1~3'7ti3 To co-operate with the telescopic capabilities of the rear axle, a new, easy to operate, outboard parking brake assembly has been developed, an embodiment of which is depicted in Figure 13.
A brake mount 140 is rigidly affixed to one of adjustable axles 124 proximal the outer end thereof, adjacent to the inner periphery of wheel 125. Accordingly, the brake mount and the remainder of the assembly attached thereto will move in and out with displacements of axle 124. A bracket 141 is affixed to mount 140. Sandwiched between the bracket and - the mount is a strip of spring steel 142 which inclines upwardly and outwardly over wheel 125 at an oblique angle thereto. The end of spring 142 is curled and is enclosed within housing 143 affixed to bracket 141. Housing 143 extends horizontally over wheel 125.
Brake lever 145 is pivotally mounted about pin 146.
More specifically, brake cam 147, affixed to the end of the brake lever, rotates in an eccentric fashion about pin 146.
Cam surface 150 of cam 147 engages spring 142 and is rounded to smoothly cooperate therewith. When lever 145 is rotated into its locked position against pin 151 and the curled portion of spring 142, as illustrated by phantom lines in Figure 13, cam 147 depresses spring 142 to bind wheel 125, thereby preventing any rotation of the wheel. It will be appreciated that the intervention of spring 142 between the cam and the wheel further serves to protect the wheel from penetration by the cam. In the released position, lever 145 is maintained in an inclined position by stop 151. It will be appreciated that in the locked position thereof brake lever 145 projects upwardly and somewhat outwardly from the wheelchair so as to be clearly 11~3 76~

visible to the operator seated above the brake. The operator can therefore easily and readily determine the operative state of the brake in marked contras-t to known brakes which do not offer a readily discernable visual impression of their operativeness.
A ball knob may be provided at the outex end of lever 145.
The present invention further contemplates improve-ments to power head 2 itself. In particular, i-t has been found advantageous from both a functional and a cost point of view to employ two xelatively small readily obtainable 12 volt motors to provide power rather than one larger, more costly motor.
The use of two motors yields added torque. Additionally, the use of two 12 volt motors in series facilitates the use of a 24 volt power supply with the result that the current which need flow through the speed controls can be cut. With reduced currents, the use of modern, smooth operating solid state controls becomes viable, particularly the use of known pulse width modulated electronic controls. The use of such controls allows for infinite power feed, smooth acceleration and an infinite choice of operating speeds. Some known wheelchairs offer a choice of only two forward speeds, slow and fast.
To accomodate two drive motors within cowling 72, a motor bracket 161 has been developed which is fixedly connected to cowling 72 and more particularly to plate 71 which is connect-ed to the cowling (Figure 3)~ The lower ends 177 of the bracket are hook shaped. Drive wheel 162 is rotatably mounted there-between in any suitable known fashion. The intermediate portion of the bracket is inclined relative to the ground and has formed into each end thereof a radius 164 providing clearance for each motors' rotor cowling 166 and drive gear 165. Slots 168 are ~3~6~

formed into the bracket to receive the motor mounting hardware.
It will be appreciated -that the tension in drive belts 171 may be adjusted by the repositioning of the motor mounts within slots 168.
With reference to Figure 15, it will be observed that motors 160 are mounted so that their rotors project in opposite directions, that is, power is taken from the left side of the uppermost motor and from the right side of the lowermost motor.
Accordingly, pulleys 169 are provided on both ends of common drive shaft 170 to receive power from drive belts 171. Power is transmitted to drive wheel 162 via sprockets 173 and 174 and chain 175. Accordingly, whereas the two drive motors are electri-cally connected in series, mechanically, they function in parallel to transmit power to drive shaft 170.
It will be appreciated that the use of a bracket as described hereinabove results in a relatively compact power head of light weight. Again, although the use of such a bracket has been described in the context of an electrified wheelchair, such a drive assembly may find application on all manner of motorized carts or vehicles of similar dimensions.

Claims (4)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A telescopic axle assembly for use on lightweight vehicles, said axle assembly comprising:
a V-shaped axle housing disposed proximal the rearward end of the said vehicle, the arms of said V extending rearwardly towards said rearward end; and an axle member having a vehicle supporting wheel rotatably affixed to the outer end thereof adjustably received within each of said rearwardly projecting arms, each of said axle members being selectively adjustable within said arms between a fully retracted and a fully extended position to simultaneously vary the wheel base and the track of said cart.

2. The axle assembly of claim 1 wherein each of said axle members include a plurality of pairs of axially aligned holes formed therein and each arm of said axle housing has axially aligned apertures formed therein, said pairs of holes being adapted to align with said apertures to receive a re-tractable pin member therethrough for fixing the position of said axle member within said arms.

3. The axle assembly of claim 2 including brake means affixed to at least one of said axle members adjacent the inner surface of said vehicle supporting wheel such that said brake means move with adjustments to the position of said axle member to remain adjacent said wheel, said brake means being adapted to prevent the rotation of said wheel and comprising; brake mounting means provided adjacent said wheel, a cam member pivotally supported by said mounting means, said cam member being actuatable between a wheel braking and a wheel releasing posi-tion and resilient means disposed between said cam member and the wheel such that in the braking position of said cam member, said cam member urges said resilient means into frictional engage-ment with said wheel.

4. The axle assembly of claim 1, 2 or 3 wherein said vehicle is a motorized wheelchair.