CA1123868A - Self-propelling and steering attachment for a wheel-chair - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
There is disclosed a self-propelling and steering attachment for a wheel-chair, of the type having larger diameter rear wheels and smaller diameter front swivel wheels. The attachment can be installed and removed by the user while remaining seated in the wheel-chair.
The attachment comprises a sleeve, a steering post rotatably supported by the sleeve, a ground-engaging steering and propelling wheel carried by the lower end of the steering post, a crank mechanism carried by the top end of the steering post, a power transmission connecting the crank and the steering and propelling wheel, a framework which is quickly connect-able to, and disconnectable from, the front frame portion of the wheel-chair, and a pair of superposed longitudinally-extending bars inter-connecting the framework and the sleeve. The upper bar is rigid with the sleeve at one end and pivots relative to the framework at the other end. The lower bar is pivotally connected to the sleeve and the framework and is extensible and retractable, being provided with a locking pin to lock this bar to a retracted, adjusted length. For installation of the attachment, the user first rigidly connects the framework to the wheel-chair front frame portion, while the locking pin is removed, then he pushes forwardly on the crank mechanism or on the upper portion of the steering post to cause the latter to attain a more upright position, therefore causing the front swivel wheels of the wheel-chair to raise off the ground. With this movement, the lower bar has retracted and the user then inserts the locking pin to lock the lower bar in retracted position. The resultant assembly behaves like a tricycle, including the two larger diameter rear wheels of the wheel-chair and the front-propelling and steerable wheel of the attachment. For removing the attachment, the user first pushes forwardly on the crank mechanism to release the lock pin, which can then be removed, whereby the front swivel wheels are lowered onto the ground, and then the framework can be removed from the wheel-chair front frame portion. The attachment may be installed on foldable or rigid wheel-chairs and on wheel-chairs of different widths.

Description

- ~.23~
- ~IELD OF THE INVENTION
Th~ preaent inventiDn relates to a self-propelling and steering attachment f~r whsel-chairs.
~ACKGROUNO OF THE INVENTION

It i~ already kno~n to provide attachments o~ the above-noted type for a wheel-ohair. For instance, reference is had to U.S. Patsnt 3,485,510, dated Decembsr 23, 1979 snd entitled: "SEL~-PROPELLING
AND STEERING ATTACH~ENT APPARATU5 FOR A WHEEL-CHAIR".
Known attachments either require considerable modification of the conventional wheel-chair or removal of the user from ths wheel-chair prior to the inatallation of the attachment.
OOOECTS DF THE INUENTION
It is th0refore the gRneral object of the pre~ent invention to provide an attachment of the character described, which can be installed and removed by the wheel-chair user himself while remaiQing seated in the wheel-chair.
Another object of the present invention relate~ to an attachment o~ the character described,which causes raising o~ the ~ront swivel wheels of the wheel-chair ofP the ground during assambly of the attachment with the wheel-chair.
Another object of the present-invention relates to an attachment o~ the character described, which may be installed on ~ wheel-chair o~ the foldable or of the rigid type and which also can be installed on wheel-chairs o~ ditferent widths.
Another object of the inve~tion rslates to an attachment o~
the character de~cribed, in which the propelling and ~teering wheel i~ power driven through a hand-actuated crank mechanism through the intermediary of a multi-speed transmission, wbereby the user can ~elect the right transmission ratio in accordance with the slops or type o~
the ground on which he is travelling.
Another object of the invention re~ide~ in the provision of an apparatus o~ the character described5 in ~hich the position o~ ths crank mechani~m can be adiusted tD suit ths us~r.

~3~3~B

SUMMARY OF THE IN~ENTION
`The attachment of the invention comprises a sleeve, a steering post rotatably supportad by said sleeve, a ground-engaging steering and propelling wheel carried by the bottorn end of said steerirlg post, a drive means carried by said steering post, a power transmi~sion means connecting said drive means to said ~taaring and propelling wheel, a rear framework having means to rigidly connect the same to~ and disconnsct it ~rom, the front frams portion of a wheel-chair, a pair of superposed bars extending lorgitudinally forwardly from the rear framework and interconnecting lû the latter and said sleeva, ons of said bars being extensible and retract-able, and pivotally connected to said rear framework and to said sleeve for pivotal movemEnt about horizontal transver3e axes relative to said wheel-chair, and the other of said bars being rigidly 3scured to one of said framework and of said sleeve and pivotally connected to ths other of said framework and of said slesve ~or pivotal mov~ment about a horizontal transverse axis relative to said wheel-chair, and further including means to lock the extensible and retractable bar to an adjusted length, whereby the wheel-chair user, while seated in th~ wheel-chair, can secure the framework to the wheel-chair front frame portion, then 2û push forwardly on the steering post to cause the same to taks a more upright position, thereby causing a change of lsngth of the unlocked extensible bar and raising of the front swivel wheels of the wheel-chair off the ground, whereupon the user locks the extensible bar in final position.
The foregoing will become clearer by referring to ths following description of a preferred embodiment and also to tha drawings, wherein:

Figura 1 is a perspective view of part of the attachment of ths invention secured to the front of a wheel~chair partially shown in dotted line;
Figura 2 iR a side elsvation of ths a~tachment 3hown in the process of being secursd to the front of a wheel-chair partially shown in dotted line;

~.23~168 Figure 3 i8 a eide elevation ~imilar to that o~ Figure 29 but showing the attachment in operative position; and figures 4 and 5 ars two cros~-sections taken along line 5-5 of Figure 2 showing the tramework of the attachment about to be aecured and fully secured, respsctively, to the front framework portion o~ the whe01-chair shown in dottad line.
In the drawings, like reference characters indicate liks elerRents throughout.
DETAILED DESCRIPTION_OF THE INVENTION
i` 10 The sel~-propelling and steering attachment of the invention is adaptsd for removable installation at the front of a conventional wheel-chair of the foldable or rigid type. Such a wheel-chair is illustrated in dotted line in the drawings and comprises a ~rame 1 including longitudinal top and bottom lateral members 2 and ~, a foldable seat 4 extending between and connected to the top members 2, arm-re~ts 5 secured to the top mambers 2, a front wheel-chair frame portion including uprights 5 rigidly secur~d to the member~ 2 and 3 at the front ends of said members. Ths whsel-chair i8 fitted with the conventionàl large diametqr rear driving wheels 6 and the front-mounted swivel wheels 7, of smaller diameter.
This conventional chair ha3 the u3ual driving rings 8 secured on the outside of the large diamster rear wheels 6, whereby the user can move about and steer the wheel-chair.
The attachment of the present invention comprises a ~tesring post 9, of the bicycle type, which extends through a sleeve 11, being rotatably mounted within said sleeve by means of roller bearing3 held in position by CUp8 lDa and lOb, there being further provided a nut arrang~ment 10 which positively prevents longitudinal displacement o~ tha st0ering post 9 relative to the sleevs 11, while allowing frea rotation of said sts0ring post 9 rslative to sleev~ 11. Nut 10 also serves to adjuRt tha longitudinal position of steering post 9 within sleava 11, A ground-engaging staering and propslling whesl 1~ is carried by the lower end o~ the steering po~t 9 through the usual ~ork memb~r 13, and this stesring wheel being of the bicycls typs and bsing fitted with ~.23~6~

th~ ugual rim 12b ~upport~d by spok~s 12c. A cDnventional mud-guard 12a partially surroundG the wheel 12 and is fixud to the lowar end o~ the ~taering post between ths tine6 o~ fork 13.
A crank mechani~m is mounted on the upper end of the steering post 9 and a transmission interconnects the crank mechanism to the wh~el 12. ~o~e sp~cifically, a ~upport arm 14 is secursd to th~ top ~nd of the steering post 9 by m~ans of a collar 15 surrounding said steering post and clamped in position by a bolt-and-wing not ass0mbly 16. The uppsr end of the support arm rotatably carries a shaft 17~ to which is sacured a crank mechanism including a pair of oppositely-directed crank arms 18 and a sprocket wheel 19. Tha outer ends of crank arm 13 are providad with handlag 2û. A power transmi~sian mechaniRm interconnect~
the crank mechanism and the steering and propelling wheel 12. This tran~-mission mechanism is of the known multi-speed type as used in bicycles.
It includes a series of sprocket wheels 21, 21a, of decreasing diameter, fixed to the wheel hub 22, which is rotatably mounted on an axle carried by the lower ends o~ fork 13. The transmission further includes a chain shifter mechanism including the shi~ting wheel ~3 and the chain t6nsioning ~heel 24, together with the driving chain 25 which is threaded between the wheels 23 and 24 and ~ngages around the sprocket wheel 19 and a sslected sprocket wheel 21, 21a. 7he lateral position of the chain shifting wheel 23 is changed by means of a hand-operated lever 26 mounted on the upper end of the steering post 9 and connected by a flexibls cable 27 to the mechanism which laterally changes the position o~ the shifting wheel 23.
~raklng means are also pro~ided; thess ~ aking ~eans are similar to tho~ used on bicycleY and include an operating lever 28 mounted on the upper end of steering post 9 and actuating,through a ~10xible cabls 29, a pair of brake shses 30. The angular posltion of ~upport arm 14 carrying the crank meGhanism can bs adjustsd by bolt-and-wing assembly t6, 80 as to bring tha crank mechanism into a position readily accessible to the wheel chair userO
Tha collar 15 can also be adjustsd longitudinally o~ the stesring post to adjust the height o~ the crank mechani~m. The slack in the driving chain 25 i9 taken up by the chain-tensioning wheel 24.
A U-shaped chain gu~rd 25a spacedly surround~ the portion of the chaln 25 in me3hing engagement with sprocket wheel 19 and is fixed to arm 14 by bracket 25b.
The attach~ent of the invention further comprise~ a rsar framework portion forming means to rigidly connect the attachment to ths front frams portion of the wheel-chair.
This rear framswork portion i~ in the form of a gsnerally lû rectangular frame adapted to be positioned in the ganeral plane o~, and between, the two upright~ 5 of the uheel-chair. Thi~ r~ctangular frame i9 rstractable and extensible 80 as to be remouably connected to ths wheel-chair. The framework comprises upper and lower horizontal tubular membera 31 and 32 rigidly interconnected by a tubular upright 33 inter-mediate the ends of members 31 and 32. Smaller diameter, inter~edlate top and bottom t~bular memb~r~ 34 and 35 are telescopically engaged within tha respecti~e horizontal top and bottom tubular members 31 and 32 and are rotatable therein, but pravented from longitudinal displacement relatiYa tD the same. An extensible and retractable as3embly comprises top and bottom tubular members 36 and 37, which are rigi~ly inter-connected intermediate their endq by a tubular upright 3~. Members 36 and 37 telsscopically engage over ths respective intermediate top and bottom members 34 and 35 for movement longitudinally of these membsrs under the action of a hand-operatad toggle lever mechanism including a pair o~
hori~ontally-di~posed and pivotally intsrconnected levers.
~ore specifically, a first 10ver 39 has ùne end pivotsd at 39a to ear~ 40 sscured to upright 38 intermediats the ends thereo~.
This lsver has a crank~haped outer end portion forming a handle 41.
A second lever 42 has its inner end pivotally at W to ears 44 secured ~0 to an inter~ediate portion of upright 33, whils ths outer end o~ the second lever 42 is pivoted at 45 to ears which are integral with the lever 39 intsr~ediate the onds thereo~. It is clear, referring to Figures 4 and 5, that manual action sxsrtsd on handle 41 towards the :~.23~368 frame will cau~ the extensible portion 36, 37, 38 to moue away from the stationary portion 31 tD 35. In tha extended position of the framework, the pivot 45 has slightly passed ths line joining the piuots 39a and 43.
Thersfore, the toggle lever remain~ in locked position without the aid o~ any Ypring or th~ like. Lever 42 has a length adjustment device 42a, oF
conventional construction, to enable adjusting ths maximum length of the framawork to fit, within limits, wheel-chairs o~ difPerent widths.
Referring to Figures 1 and 2, it will bs s~en that the outer ends of the top horizontal members 31 and 36 are each fitted with a pair of outwardly-projecting spaced parallel lugs 46 adapted to extend on opposit~
sides of uprights 5,the 1U9A having a slight fit with said upright~ S.
Similarly, the bottom horizontal membsrs 32 and 37 are each prouidsd at their outer ends with an outwardly-projecting top lug 47 and a laterally-and outwardly-extendlng L-shaped latsral lug 48.
The top lug 47 is adapted to overlap the lower harizontal member 3 of tha wheel-chair, while the lateral lug 48 is adapted to overlap the ~ront face o~ the upright 5. When the framework i~ f~xed to the wheel-chair, it becomes rigid with the frame of the latter, becausa lugs 46, 47, and 48 engage on both Aides of the uprights 5 and, there~ore, top members 31, 36 and bottom members 32, 37 cannot move forwardly or rearwardly with respect to the wheel-chair frame, and also because top lugs 46 abut underneath the top horizontal ~rame member 2 of the wheel-chair ~rame while the lugs 47 overlie the lower horizontal member 3, therefore preventing vertical displacement of the framework with rsspect to the wheel-chair frame.
It will be noted that the intermsdiats top and bottom members 34 and 35 are arrang0d for rotation mov~ment about their rsspective longitudinal axis within the top horizontal members 31, 36 and bottom horizontal msmbers 32, 37. However, meansg not shown, are provided to prevent longitudinal diaplacement of the intermediate top and bottDm member~ 34, 35 relative to the top and bottom members 31 and 32.

A pair of superpo~ed bars, whioh extand longitudinally with r~spect to the wheel-chair centrally of the same and ~orwardly, s0rve to ~i~ 2i3~

connect ths framswork attached to the whssl-chair to the slaeve 11. ~ore spQcifically, straight bar 49, in the form of a rigid tube, i8 welded or otherwise rigidly sscursd to the intsrm0diate top msmber 34 at 50, while the front end of top bar 49 i9 rigidly secured to th~ upper end portion of sleeve 11, as ~hown at Sl. The low0r bar is a t~lescopic bar mad0 of two tubular ~ection3, namely: an inner s~ction 52, which is rigidly sscured, such as b0ing welded, to the bottom intermediate member 35 and sxtsnds perpendicular thereto, and an outsr ssction 53, which is pivoted at 54 to ear~ 55, which are weldsd, or othsrwise ~0cur0d, to ths lower portion of slse~e 11. The pivotal axis o~ pivot 54 is parallel to t~le pivotal axis of the rotational movement of the intermediate top and bottom member~ 34 and 35 relative to the framework asssmbly 31 to 38, and thess axes extsnd horizontally transverse to the wheel-chair. A
locking pin 56 is adapted to be inserted through transversely-r~gist0ring holes of this section and to extend through another hole of the inner 3ection 52 when the two section~ 52 and 53 are in a predeterminsd retracted position.
A tension spring 57 i~ attached to the out~r section 53 by means of a collar 58 and to the outer end of an L-shaped arm 59 secured to the lower end of steering post 9. This tension spring serves to automatically align the main wheel 1~ ln the central longitudinal plane of the wheel-chair and attachment assembly when the crank arms 19 are released.
The attachment is installed on the ~rame of the wheel-chair in the following manner:
The wheel-chair user, while seated within the wheel-chair,can grasp the attachmsnt normally stored in an accas~ible placa. He removss ths locking pin 56. While retaining the top bar 49, hH aligns lugs 4Ç 9 47,and 48 with ths respective uprights and the lower longitudinal members 3 of ths wh~el-chair ~rams. Then he opsrates the handle 41 of the toggle lever mechanism to extend th0 framswnrk and lock the sam~ in pn~ition ~ecursd to the front portion of th~ whs~l-chair frame, 3~ shown in Figur~s ~ and 5.

~ ~.23~68 It will be noted that, at this stage, the Pront swi~el wheels 7 of the wheel-chair still rest on the Floor, as shown in Figur~ 2 Then the user, while still ~eated in the wheel-chair, simply pushes on the chain guard 25a or on the bar 14 in a forward dir0ction, a~ indicated by the arrow 60 in Figure 2, 80 as to pivot the assembly cf the upper bar 49, slaeve 11 and ~teering post 9 about the pi~ot axis of the intermediate top member 34 re3pectiv0 to tha top horizontal mambers 31 and 36. During this mo~ement, the Rleeve 11 takes a more vertical attitude and the inner section 52 retracts within the outer section 53, as shown by arrow 61, and main wheel 12 is moved nearer the wheel-chair, as shoun by arrow 61a9 and causes lifting movament of the wheel-chair front portion and of the swivel wheels 7, as indicated by arrow 62. Ths user then inserts the locking pin 56 in locked position through the aligned holes of the inner and outer tubular sections 52 and 53 to lock the sections in retracted position. Obuiously~
the locking pin 56 can be arranged to be retained by section 53 and fittsd with a spring to bias the same into locking positlon. Such a spring would then retain the locking pin in unlocking position and bearing against a non-perforated portion of inner section 52 when the two sections are in extended position. The pin would then automatically move into locking position when the two sections 52, 53 of the lower bar ha~e reachsd their limit retracted position in which their holes are in alignment.
In such a case, the user can use both hands to gra~p both crank handles for pushing forwardly.
The combination of the upper and lower bar, of the ~leeve 1~ and of the uprights 33 and 38, or of the uprights 5, form a deformable four-sided figure. It is essential that ths telescopic bar be pivoted at both ends to the sleeve 6 and to the framework. Out this telescopic bar could be arranged as the upper bar instead of being the lower bar 9 as shown in the drawingg, in which ca3e the rigid bar, namely upper bar 49, would become the lower bar. ~orsover, it is sssential that the rigid bar 49, namely the non-extensibls one, be rigidly sacure~ either to the ~lea~e 11, as shown in the embodiment just described, or to the framawork connected to ths wheel-chair frame, in which latter case the outar end of the rigid ~;.2;~68 bar would be pivo~ally connected to tha sleevs 11. In this lattsr smbodiment, the intermediate top member 34 would be rigidly secured to the top horizontal member 31.
Since the four-sided deformable frame extende longitudinal}y in the central plane of the wheel-chair, it i8 ~a~y for the user to str~ddle this frame with his two legs and to rest his leg~ on the usual foot-rosts, not 3hown. Operation of the crank mechanism at a selsctive epeed ratio snablsQ the user to mw e about on euen quite steep slopes and in all kinds of terrains, including gravel roads, mud- or snow-covered ground. As lC described hereinabove, the apparatus can be easily insta}led on the wheel~chair by the user him3elf who remains seated in the wheel-chair.
It is similarly easily removed by e~fecting ths rsverse opsration ~rom that noted above, that is the crank mechanism i8 slightly pushed forwardly to releaae the locking pin which is than fully retracted, whereby the swival wheels 7 are lowered to the ground and then the handle 41 o~ the toggle lever mechanism i8 simply pushed forwardly to retract the talescopic portion of the framework, which can then be removsd from the wheel-chair ~rame.
The power transmission mechanism can be such as to obtain a poasibility of ten different transmission ratios, It i3 also possible to install a battsry-oparated electric motor or a gasoline engine to drive wheol 12.

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Claims (9)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED, ARE DEFINED AS FOLLOWS:

1. A self-propelling and steering attachment for a wheel-chair of the type having a frame, rear larger diameter wheels supporting said frame and front smaller diameter swivel wheels supporting said frame at the front frame portion thereof, said attachment comprising a front sleeve, a steering post rotatably supported in said sleeve, a ground-engaging steering and propelling wheel carried by the bottom of said steering post, drive means for said steering and propelling wheel, a rear framework, means on said framework to rigidly connect and disconnect the same to and from the front frame portion of said wheel-chair, and two superposed bars extending longitudinally forwardly from said rear framework and interconnecting the latter and said sleeve, one of said bars being extensible and retractable and pivotally con-nected to said rear framework and to said sleeve for pivotal movement about horizontal transverse axes relative to said wheel-chair, and the other of said bars being rigidly secured to one of said framework and of said sleeve and pivotally connected to the other of said framework and of said sleeve for pivotal movement about a horizontal transverse axis relative to said wheel-chair, and means to lock said extensible and retractable bar to an adjusted length, whereby a wheel-chair user while seated in the wheel-chair, can secure said framework to said wheel-chair front frame portion when said locking means are in released position and while said front swivel wheels of the wheel-chair rest an a support surface, and then the user can lift said swivel wheels off the ground by pushing forwardly of said steering post to cause the same to take more vertical attitude, thereby causing a change of length of said extensible and retractable bar and then locking the latter in its final position with the swivel wheels remaining raised off the supporting surface and the wheel-chair resting on said supporting surface only by the rear large diameter wheels and the steering and propelling wheel.

2. A self-propelling and steering attachment as claimed in claim 1, wherein said other of said bars is rigidly connected to said sleeve and pivotally connected to said rear framework.

3. A self-propelling and steering attachment as claimed in claim 2, wherein said other of said bars is the upper one and said extensible and retractable bar is the lower one.

4. A self-propelling and steering attachment as claimed in claim 1, 2 or 3, wherein said rear framework consists of an elongated frame including top and bottom horizontal members extending perpen-dicularly to, and connected to, said two superposed bars, respectively, each of said top and bottom horizontal members being made of telescopic-ally-engaged sections, each end section of each member having endwise protruding lugs at their outer ends engageable with the front frame portion of said wheel-chair and manually-operated toggle lever means to move said telescopic sections between a retracted position clearing said front frame portion, and an extended position with the lugs firmly engaging said front frame portion of said wheel-chair, and uprights rigidly interconnecting the telescopic upper and lower sections, respectively.

5. A self-propelling and steering attachment as claimed in claim 1, 2 or 3, wherein the wheel-chair front frame portion includes top and bottom lateral, horizontally-extending members on each side of the chair, and uprights rigidly interconnecting said top and bottom members and said framework includes a generally rectangular frame adapted to extend between the two uprights of the wheel-chair frame and including top and bottom horizontal members consisting of three telescopic sections, namely two end sections and an intermediate section, said intermediate section being rigidly connected at right angles to the upper bar and being rotatably mounted within the two end sections, one section of the retractable and extensible bar being rigidly secured at right angles to the intermediate section of the lower horizontal member, uprights rigidly interconnecting the upper and lower and sections two by two, the end sections of the upper horizontal member being provided with endwise protrud-ing lugs adapted to have a sliding fit on each side of the uprights of the wheel-chair, the end sections of the lower horizontal member being provided with rigidly secured, endwise projecting lugs adapted to engage over the lower lateral horizontal side members of the wheel-chair frame rearwardly of the uprights and lateral lugs engageable with and having a sliding fit with the front of the uprights of the wheel-chair, and a manually-operated toggle lever system interconnecting the two uprights of the framework to extend a pair of upper and lower end sections longitudinally with respect to the other pair of lower and upper end sections, so as to cause engagement of the lugs with the respective uprights and with the lower horizontal member of the wheel-chair frame.

6. A self-propelling and steering attachment as claimed in claim 1, wherein said drive means include a crank means carried by the top of said steering post, and a power transmission means including means to change the speed ratio between said crank means and said steering and propelling wheel.

7. A self-propelling and steering attachment as claimed in claim 1, 2 or 3, further including spring means biasing said steering and propelling wheel in a position in alignment with the central trans-verse plane of the wheel-chair fitted with the attachment.

8. A self-propelling and steering attachment as claimed in claim 6, wherein said crank mechanism is supported at the upper end of said steering post for adjustable positioning thereof to suit users having different arm lengths.

9. A self-propelling and steering attachment as claimed in claim 6, further including a support arm adjustably pivotally secured at one end to the upper end of said steering post and carrying said crank means at its other end.