PERSONAL MOBILITY VEHICLE

Abstract: A personal mobility vehicle is described of the kind comprising a chassis, a seat for a user mounted on the chassis, a rear axle bearing wheels, drive means arranged to drive the rear wheels, a front axle bearing at least one wheel and a steering tiller (10). The vehicle further comprises connection means (21) adapted to connect the steering tiller (10) to the front axle such that the inclination of the tiller with respect to the front axle is alterable to provide a plurality of use positions and such that the tiller is demountable from the vehicle.

Description: Title: Personal Mobility Vehicle Description of Invention The invention relates to a personal mobility vehicle of the kind generally known as a wheelchair, and in paiticular to such chairs which are powered and have tiller steering. Such wheelchairs are by their very nature bulky when in their in use configuration. Clearly, it is preferable, for ease of storage and/or transport of such wheelchairs, for it to be possible to reduce them in size from their in use configuration. There are a number of ways of doing this known in the prior art, including folding of the steering tiller downwards and separation of the front and rear chassis portions. It is an object of the present invention to provide an alternative way of overcoming the above identified problem. According to the invention there is provided a personal mobility vehicle comprising a chassis, a seat for a user mounted on the chassis, a rear axle bearing wheels, drive means airanged to drive the rear wheels, a front axle bearing at least one wheel and a steering tiller wherein it further comprises connection means adapted to connect the steering tiller to the front axle such that the inclination of the tiller with respect to the front axle is alterable to a plurality of use positions and such that the tiller is demountable from the vehicle. The invention provides the advantage that the tiller is adjustable to a plurality of use positions making it more likely that there will be one which is particularly comfortable for the user, and is demountable to reduce the size of the vehicle for storage or transport. Preferably the tiller is lockable in each of the plurality of use positions. The tiller may be pivotable to a plurality of discrete use positions. In such an embodiment the connection means may comprise a rack, being a segment of a circle with a centre and a plurality of teeth around it's circumferential portion, connected to the front axle and engagement means may be provided on the tiller adapted to engage the teeth. Preferably in such an embodiment the tiller is bifurcated at its lower end and the connection means further comprises a spindle attached to the bifurcated end of the tiller and a receiving formation attached to the front axle for receipt of the spindle such that when received within the formation the spindle is located at the centre of the rack, the rack being between the bifurcated ends of the tiller, and the tiller being pivotable about the spindle. The receiving formation may conveniently comprise a forward opening slot provided in the rack with a downwardly inclined portion providing a bearing surface at its closed end. The connection means may further comprise an arcuate groove on each side of the rack which are open at their forward ends and protrusions on inner surfaces of the bifurcated ends of the tiller adapted to engage in the grooves and to move along them as the tiller is pivoted. The engagement means may comprise biassing means which bias it into engagement with the teeth and means are provided for the user to disengage the engagement means against the bias to pivot the tiller to an alternative use position or to demount the tiller from the vehicle. In the an alternative the tiller may be pivotable to a continuous range of use positions between a foremost use position and a rearmost use position. Preferably the tiller comprises a trapezoidal arrangement of front, rear, upper and lower members which are pivotally connected by means of spindles, and pivoting of the front and rear members with respect to the lower member permits alteration of the inclination of the tiller. A friction locking mechanism adapted to lock the tiller in any desired position between the foremost and rearmost positions, may be provided. In such an embodiment the connection means may comprise a first portion connected to the front axle and providing receiving means and a locking formation, and a second poition connected to the tiller and providing formations adapted to be received in the receiving means, and a locking element adapted to engage with the locking formation to retain the tiller in connection with the front axle. The receiving means may comprise front and rear pairs of slots and the formations adapted to be received within them comprise portions of the spindles pivotally connecting the front and rear tiller members to the lower tiller member. The locking formation may comprise a hole in the second portion of the connection means having a first diameter, and the locking element comprises a pin having a second diameter, the second diameter being a little smaller than the first diameter. Preferably the pin is biassed into engagement with the hole and a disengagement means is provided for operation by the user. The disengagement means may comprise a cable attached to a first end of the pin, the second of the pin having a tapered profile for engagement with the hole. Preferably when the vehicle is new the location of the hole and pin with respect to the receiving means are such that the alignment of the pin with the hole is not exact but is sufficient for the tapered profile of the pin to engage in the hole to peifoπn the locking function, and as the receiving means wear the alignment of the pin the hole improves such that the engagement of the pin in the hole increases. Embodiments of personal mobility vehicles according to the invention will now be described, by way of example only, with reference to the accompanying drawings in which: FIGURE 1 illustrates in cross section a fust embodiment of the invention; FIGURE 2 illustrates in cross section a second embodiment of the invention; FIGURE 3 illustrates the main components of the embodiment of Figure 2 in exploded detail; FIGURES 4a to c illustrate a part of the Figure 2 embodiment in more detail, and FIGURE 5 illustrates the foremost and rearmost use positions of the embodiment of Figure 2. The invention relates to a personal mobility vehicle, or powered wheelchair, of the kind having a chassis, a seat mounted on the chassis, a rear axle bearing wheels, and drive means airanged to drive the rear wheels. However, as these parts of the vehicle are not dependent on the present invention they will, for brevities sake, not be described here. The present invention concents the steering tiller provided for such a vehicle. A first embodiment of the invention will now be described with reference to Figure 1. The tiller 10 comprises a main member 1 1 , in the general shape of a "dog-leg", which carries at it's upper end handle bars 12, to which are attached the various controls provided for such vehicles. A forward facing light 13 is provided on a mid-portion of the main part 1 1, although this is not a necessity for such vehicles. The tiller 10 is clad with body work 14 to make the vehicle look attractive. At it's lower end the tiller 10 further comprises a bifurcate member 15 providing forks 15a, 15b with a spindle 16 passing through holes provided in the lower ends of the forks 15a, 15b. Protrusions 28 are provided on the inner surface of each fork 15a, 15b, the puipose of which will become clear below. Further an engagement means is provided within the lower poition of the main member 11 and the upper poition of the bifurcate member 15. The engagement means comprises a elongate rod 17, with at it's lower end a toothed foimation 18, and biassing means in the fonn of a compression spring 19 which biasses the rod 17 and toothed portion downwards. At the upper end of the rod 17 disengagement means are provided in the fonn of a lever 20 operable by the user of the vehicle. The vehicle comprises connection means 21 adapted to connect the tiller 10 to the front axle of the vehicle in a manner which permits steeling of the vehicle. The connection means may be connected to the front axle in any appropriate manner and therefore that connection will not be described here. The connection means 21 comprises a rack 22, being a segment of a circle with a centre and a plurality of teeth 23 around it's circumferential poition. It further comprises a forward opening slot 24, having a downwardly inclined poition 25 towards it's closed end. A bearing surface 26 is provided at the closed end of the slot 24. The connection means 21 further comprises, on each side of the rack 22, an arcuate groove 27 which is open at its forward end. Each arcuate groove 27 foims a part of a circle centred at the centre of the rack 22. the rack is further provided with a cam surface 29 between the slot 24 and the toothed circumference. The manner of connection of the tiller 10 to the connection means 21, and of it's pivoting will now be explained. To connect the tiller 10 to the vehicle it is held in an approximately horizontal orientation in front of the vehicle, the spindle 16 is engaged in the slot 24, and the tiller 10 moved such that the spindle moves to tl e rear of the slot 24 and onto the bearing suiface 26. The tiller 10 is then pivoted about the spindle such that the toothed formation 18 rides up over tlie cam suiface 29 and tlie protrusions 28 engage in tlie respective grooves 27. The tiller 10 will at this point be located at it's foremost use position, with the toothed formation 18 engaged with the foremost teeth 23 of the rack 22. To pivot the tiller 10 to the desired inclination, the lever 20 is depressed downwards to the lower position illustrated in Figure 1 , to raise the rod 17 against the bias of the spring 19 and hence hold the toothed fonnation 18 clear of the teeth 23 of the rack 22. The tiller 10 is then pivoted about the spindle 16 to the desired inclination with respect to the vehicle, and the lever 20 released. The toothed foimation 18 is thus biased into engagement with the appropriate teeth 23 of the rack 22 to lock the tiller 10 at or close to the desired inclination. To demount the tiller 10 the process of connection described above is reversed, with the additional requirement that the lever 20 must be held in the depressed condition whilst the protrusions 28 are disengaged from the grooves 27, as their is no cam surface provided for movement in this direction to prevent accidental demounting of the tiller 10. A second embodiment of the invention will now be described with reference to Figures 2 to 4. A tiller 40 supports on its upper end handle bars 41 which bear tlie various controls provided on such a vehicle. In addition a forward facing light 42 is provided. The tiller 40 is clad with bodywork 43 to make the vehicle attractive and to protect the tiller 40 and other parts such as electrical wiring. The tiller 40 comprises a front member 51 , a rear member 52, an upper member 53 and a lower member 54. The front and rear members 51 , 52 comprise elongate portions 51a, 52a with perpendicular tube portions 51b, 51c, 52b, 52c at either end. The upper member 53 comprises a substantially flat central portion 53a with down turned right and left side poitions 53b, 53c, the side poitions 53b, 53c having aligned front and rear pairs of holes 53d, 53e therethrough. Likewise the lower member 54 comprises a substantially flat central poition 54a with upturned right and left side poitions 54b, 54c having aligned front and rear pairs of holes 54d, 54e therethrough. The front and rear members 51, 52 are pivotally connected to the upper member 53 by means of spindles 55 and 56 passed through holes 53d and tube poition 51b, and through holes 53e and tube portion 52b, respectively. Likewise the front and rear members 51,52 are pivotally connected to the lower member 54 by means of spindles 57 and 58, passed through holes 54d and tube poition 51c, and through holes 54e and tube poition 52c, respectively. Hence, the members 51 to 54 are pivotally connected to provide a trapezoidal arrangement. Where the front and rear members 51. 52 are pivotally connected to the lower member 54, pairs of bearings 59 and 60 respectively are provided. The bearings 59, 60 are located on the spindles 57, 58 outwardly of the upturned side portions 54b, 54c of the lower member 54. The lower member 54 further comprises an upstanding tube 54f located above and aligned with a hole through the flat central portion 54a. The tube 54f receives within it a locating pin 61, which is attached to a cable 62 at it's upper end and has a tapered profile 61a to it's lower end. At it's other end the cable 62 it connected to a pull handle 63 which is mounted on the bodywork 43. The pin 61 is biassed downwardly from the tube 54f by biassing means (not shown). The tiller 40 further comprises a locking means 70. in the fonn of a proprietary friction locking mechanism (Porter MM 65 2007). The lower end of a first part 70a of the locking mechanism 70 is retained on spindle 57 along with tlie front member 51. A mid poition of a second part 70b of the locking mechanism 70 is pivotally attached to brackets 71 provided on the rear member 52. The second part 70b contains the operative portion of the locking mechanism 70. A mid portion of the locking mechanism 70 is also connected to a first end of a cable 72, the second end of which is attached to appropriate operative means on the handle bars 41. The first part 70a of the locking mechanism 70 comprises a rod is encircled by the operative poition within the second part 70b. When the cable 72 is operated, the operative poition releases the rod and the two parts 70a, 70b can slide relative to each other. When the cable 72 is released the operative poition grips the rod, and locks the first and second parts 70a, 70b in their respective positions. The vehicle comprises connection means 64 adapted to connect the tiller 40 to the front axle of the vehicle in a manner which peπnits steeling of tlie vehicle. The connection means 64 may be connected to the front axle in any appropriate manner and therefore that connection will not be described here. The connection means 64 comprises a pair of plates 65 spaced apart by means of front and rear spacing members 66, and a central member 67 which has a hole 67a therethrough. The plates 65 each comprise front receiving means 68 and rear receiving means 69. The receiving means 68, 69 each comprise downwardly and forwardly inclined slots, with upward openings towards their rearward ends. The manner of connection of the tiller 40 to the connection means 64, and it's pivoting will now be described. To connect the tiller 40 to the connection means 64 the tiller is held in a roughly vertical orientation, and the bearings 59 and 60 are located in the receiving means 68 and 69 respectively. The tiller 40 is slid forwards until the bearings 59 and 60 are located at the forward ends of die receiving means 68 and 69. In this position the pin 61 is aligned with the hole 67a in the central member 67 of the connection means. As the pin 63 is biassed downwardly it automatically engages in the hole 67a to retain the tiller 40 in place. Allowance for wear in the receiving means 68 and 69 is provided as follows. When tlie vehicle is new the alignment of the pin 61 with the hole 67a is not exact, as shown in Figure 4a. However, due to the tapered profile 61a of the tip d e pin 61 does engage in the hole 67a sufficiently to lock the tiller 40 in position. As the forward ends of the receiving means 68 and 69 wear, the lower member 54 moves further foiwards with respect to the connection means 64 and the alignment of the pin 61 with the hole 67a improves, as shown in Figure 4b, before deteriorating again as shown in Figure 4c. This doubles the useful life of the connection means 64 before it requires replacement due to wear of the receiving means 68 and 69. To alter tlie inclination of the tiller 40 with respect to the vehicle, the operative mechanism on the handles bars 41 is used thus operate cable 72, and releasing the locking mechanism 70. The tiller 40 is then moved to the desired inclination, with pivoting between the members 51 to 54 in the trapezoidal arrangement occuπing to allow the movement, and the operative mechanism is then released to re-engage the locking mechanism 70 to lock the tiller in the new position. The trapezoidal arrangement is particularly useful as the upper and lower members 53, 54 remain horizontal for all tiller inclinations. Thus the handle bars 41 and more importantly the light 42 move in a translational manner rather than a rotational manner, and retain their coirect alignment. Figure 5 illustrates the tiller 40 in its foremost and rearmost positions. o demount the tiller 40 from the vehicle the method of connection is reversed, with the additional step of pulling on handle 63 to operate cable 62 and disengage the pin 61 from the hole 67a.

Claims: CLAIMS 1. A personal mobility vehicle comprising a chassis, a seat for a user mounted on the chassis, a rear axle bearing wheels, drive means airanged to drive the rear wheels, a front axle bearing at least one wheel and a steering tiller wherein it further comprises connection means adapted to connect the steering tiller to the front axle such that the inclination of the tiller with respect to the front axle is alterable to provide a plurality of use positions and such that the tiller is demountable from the vehicle. 2. A vehicle according to claim 1 wherein the tiller is lockable in each of die plurality of use positions. 3. A vehicle according to claim 1 or 2 wherein the inclination of die tiller is alterable by means of pivoting to a plurality of discrete use positions. 4. A vehicle according to claim 3 wherein the connection means comprises a rack, being a segment of a circle with a centre and a plurality of teeth around it's circumferential poition, connected to die front axle and engagement means are provided on the tiller adapted to engage the teeth. 5. A vehicle according to claim 4 wherein the tiller is bifurcated at its lower end and the connection means further comprises a spindle attached to the bifurcated end of the tiller and a receiving foimation attached to the front axle for receipt of the spindle such that when received within the foimation the spindle is located at the centre of die rack, the rack being between the bifurcated ends of the tiller, and the tiller being pivotable about the spindle. 6. A vehicle according to claim 5 wherein the receiving foimation comprises a forward opening slot provided in the rack witii a downwardly inclined portion providing a bearing surface at its closed end. 7. A vehicle according to any one of claims 4 to 6 wherein the connection means further comprises an arcuate groove on each side of the rack which are open at their forward ends and protrusions on inner surfaces of the bifurcated ends of the tiller adapted to engage in the grooves and to move along them as the tiller is pivoted. 8. A vehicle according to any one of claims 4 to 7 wherein die engagement means comprises biassing means which bias it into engagement with the teeth and means are provided for the user to disengage the engagement means against the bias to pivot the tiller to an alternative use position or to demount the tiller from the vehicle. 9. A vehicle according to claim 1 or 2 wherein the inclination of the tiller is alterable to a continuous range of use positions between a foremost use position and a reaimost use position. 10. A vehicle according to claim 9 wherein the tiller comprises a trapezoidal airangement of front, rear, upper and lower members which are pivotally connected by means of spindles, and pivoting of the front and rear members with respect to the lower member peπnits alteration of the inclination of the tiller. 11. A vehicle according to claim 9 or 10 wherein it comprises a friction locking mechanism adapted to lock the tiller in any desired position between the foremost and rearmost positions. 12. A vehicle according to any one of claims 9 to 1 1 wherein the connection means comprises a first portion connected to the front axle and providing receiving means and a locking foimation, and a second poition connected to the tiller and providing foimations adapted to be received in the receiving means, and a locking element adapted to engage with the locking foimation to retain the tiller in connection with the front axle. 13. A vehicle according to claim 12 wherein the receiving means comprise front and rear pairs of slots and the formations adapted to be received within them comprise portions of the spindles pivotally connecting die front and rear tiller members to the lower tiller member. 14. A vehicle according to claim 12 or 13 wherein the locking foimation comprises a hole in the second portion of the connection means having a first diameter, and the locking element comprises a pin having a second diameter, the second diameter being a little smaller tiian the first diameter. 15. A vehicle according to claim 14 wherein the pin is biassed into engagement with the hole and a disengagement means is provided for operation by the user. 16. A vehicle according to claim 15 wherein the disengagement means comprises a cable attached to a first end of the pin, the second of die pin having a tapered profile for engagement with the hole. 17. A vehicle according to claim 16 wherein the when the vehicle is new the location of the hole and pin with respect to the receiving means are such that the alignment of the pin with the hole is not exact but is sufficient for the tapered profile of the pin to engage in the hole to perfoim the locking function, and as the receiving means wear d e alignment of the pin the hole improves such that the engagement of die pin in the hole increases. 18. A vehicle substantially as hereinbefore described with reference to Figure 1 of the drawings. 19. A vehicle substantially as hereinbefore described with reference to Figures 2 to 5 of the drawings.

Inventors: GILLETT PETER WILLIAM, GOULD ROYSTON MERVYN, GILLETT, PETER, WILLIAM, GOULD, ROYSTON, MERVYN
Applicants: GILLETT PETER WILLIAM, GOULD ROYSTON MERVYN, SUNRISE MEDICAL LTD, GILLETT, PETER, WILLIAM, GOULD, ROYSTON, MERVYN, SUNRISE MEDICAL LIMITED
Application year: 1998
Main classification: B62K5
IPC codes: A61G5, B62K5, B62K15, G05G1