WO1994006326A1

WO1994006326A1 - Leg rest assembly for a wheelchair

Info

Publication number: WO1994006326A1
Application number: PCT/US1993/008962
Authority: WO
Inventors: A. Scott Robertson; Richard Geiger; James Wade
Original assignee: Medical Composite Technology
Priority date: 1992-09-21
Filing date: 1993-09-21
Publication date: 1994-03-31

Abstract

An angularly adjustable leg rest assembly (82) for a wheelchair includes a leg rest extension (183) having a top (184) and a bottom (185) end. An extension hub member (186) and a frame hub member (210) are each positioned at a top end of the leg rest extension. The extension hub member has projections (187, 211) for interengagement with the frame hub member. Also included is structure (202) for engaging and disengaging the projections for interengagement of the extension hub member with the frame hub member at various angular relationships.

Description

LEG REST ASSEMBLY FOR A WHEELCHAIR Field of the Invention

The present invention relates to wheelchairs. More specifically, the present invention relates to an adjustable, removable, lightweight leg rest assembly for a wheelchair.

Background of the Invention

Wheelchairs are well known transportation appliances enabling the infirm, disabled and unwell person to move about with greater mobility than otherwise. Essentially, wheelchairs are small, single person conveyances typified by a chair supported by two outer large diameter drive wheels behind the center of gravity of the user, with two smaller swivel-mounted pilot wheels or casters located in front of the user's center of gravity, and a leg support device descending from the seat between the drive wheels. The chair may include a padded seat, or it may include a webbing or sling seat. Alternatively, the chair may be molded from a suitable material. A back rest is also typically provided for the user's comfort. Motive power may be supplied by an attendant pushing the wheelchair, by the user's hands and arms, or by auxiliary power sources.

While wheelchairs following many different designs have proliferated, there have been drawbacks heretofore remaining to be solved. In order to meet the needs and demands of the physically handicapped user, wheelchairs must be versatile and easily and readily adapted to accommodate the particular body shape and size of the user. Wheelchairs must also be versatile in adapting to both ambulatory and recreational travel, and they must be sufficiently rugged and durable to provide comfortable passage over uneven and irregular surfaces. For instance, the leg support device may be difficult to remove from the wheelchair seat for storage, travel or for the unique needs of double amputees. Leg support systems have not been readily adaptable to the single or double amputee, nor have the prior art systems readily provided individual leg length or ankle angle adjustment capability. In addition, the leg support device may not be sufficiently adjustable to permit the device to be moved out of position for ease in entering or exiting the wheelchair. One more drawback has been the lack of fully adjustable leg support devices to provide sufficient therapeutic knee and ankle support positions.

A hitherto unsolved need has arisen for a lightweight, fully adjustable leg rest assembly for a wheelchair. Yet another unsolved need has been to provide a more fully collapsible and detachable leg rest assembly for a wheelchair whereby the leg rest assembly may be removed from the wheelchair or folded underneath a removable wheelchair seat to permit the wheelchair to be stowed in pieces in small spaces, such as an overhead storage compartment on an airplane.

Summary of the Invention with Objects A general object of the invention is to provide a leg rest assembly for a wheelchair that overcomes the limitations and drawbacks of the prior art.

A more specific object of the present invention is to provide a detachable, fully adjustable leg support module, the leg rest enabling a wide range of knee angles to be selected, the leg support module further enabling individual leg length adjustments. A further object of the invention is to provide an easily detachable, lightweight leg support module for a wheelchair.

Yet another specific object of the present invention is to provide a leg support module for a wheelchair which may be easily folded beneath a removable wheelchair seat and stored in small spaces, such as the overhead compartment of an airplane.

One more specific object of the present invention is to provide a leg rest assembly for a wheelchair that may be easily adapted for use with a variety of other wheelchair designs.

Yet one more object of the present invention is to provide a leg rest assembly for a wheelchair providing substantially 90 degrees of rotation thereby enabling the system to be folded under the seat to facilitate entry and exit from the wheelchair, and providing incremental knee angle adjustment from 0 to 90 degrees.

Still another object of the present invention is to provide a leg rest assembly with an independently adjustable footrest for enabling a wide range of ankle angles to be selected independent of, or in conformity to, the selected knee angle.

In accordance with one aspect of the present invention, a generally T-shaped leg rest assembly is provided having two vertically aligned tubes connected along a common seam. The tubes are removably attached by compression clamps to a cross-bar on the seat assembly of the wheelchair. When released, the compression clamps permit the leg rest assembly to pivot posteriorly substantially 90 degrees to swing the leg rest assembly under the seat, and further to pivot anteriorly substantially 90 degrees to completely extend the knees of the user. A common lever compresses and releases the compression clamps.

In this aspect, two footrest shafts independently telescope within the vertically aligned tubes. Locking mechanisms lock the desired position of each footrest shaft. Footrests extend laterally from and perpendicular to each footrest shaft, the footrests having a lateral support, tensioned cable extending vertically from the footrest to attach to the seating system. The rod enables ankle straps and calf support slings to be attached to the leg rest assembly.

In another aspect of the present invention a single T-shaped vertical tube is provided and removably attached by compression clamps to a cross-bar on the seat assembly. The tube defines two interior races for attaching the independently telescoping transverse foot support sections which each have an anterior protruding extension terminating in a bumper knob. The transverse foot support section is elliptically shaped thereby permitting the user to adjust the angle of his or her ankle.

In one or more aspects of the present invention, the transverse foot support sections are pivotally attached to the vertical tubes which telescope within the bar. The pivot attachment enables the ankle angle to be independently adjusted and to be adjusted in conformity to the selected knee angle.

In still one more object of the present invention, the leg rest assembly is formed by a generally U-shaped bar having the legs of the "U" descending as lateral bars which provide protection against the side impact, the lateral bars being particularly suitable for sports uses. In this embodiment, the foot support assembly adjusts upwardly and downwardly within the two bars and further telescopes in the mid-region of the foot support area.

In one more aspect of the present invention, a leg rest assembly is provided with two leg rest extensions being pivotally mounted on, and angularly adjustable relative to, a wheelchair frame. An extension hub member and a frame hub member each have projections for interengagement with other hub members, and clamping means are provided to engage and disengage the projections for interengagement for angularly adjusting the leg extensions relative to the wheelchair frame.

These and other objects, advantages, aspects and features of the present invention will be more fully understood and appreciated by those skilled in the art upon consideration of the following detailed description of the preferred embodiments, presented in conjunction with the accompanying drawings.

Brief Description of the Drawings In the Drawings:

Fig. 1 is a front view in elevation of a modular wheelchair incorporating a leg rest assembly of the present invention;

Fig. 2 is a side view of the leg support assembly of Fig. 1 ; Fig. 3 is a front view in elevation of the modular wheelchair of Fig. 1 showing the independent adjustment of the footrest shaft length to accommodate differing leg lengths; Fig. 4 is an enlarged view in partial section of the leg rest assembly of Fig. 1 showing the compression clamp attachment to the seating system and an adjustment mechanism of the telescoping footrest shafts;

Fig. 5 is a side view in elevation of the leg rest assembly attached to a seating system and showing the angle of rotation provided by the pivoted compression clamp attachment;

Fig. 6 is a front view in elevation incorporating an aspect of the present invention showing a single vertical tube and the bumpers on the footrest;

Fig. 7 is a side view of the wheelchair of Fig. 6 showing the elliptical foot rest;

Fig. 8 A is a front view in elevation of a wheelchair incorporating a leg rest assembly having pivotal foot rests for adjusting the user's ankle angle;

Fig. 8B is an enlarged side view of the pivot mechanism of the footrest;

Fig. 9 is a front view in elevation of an aspect of the leg rest assembly showing two lateral leg support tubes and the adjustment mechanisms shown in hidden view;

Fig. 10 is an enlarged view in partial section of an aspect of the leg rest assembly showing telescoping outer rigid cables and a clamp mechanism for securing the selected leg length adjustment mechanism;

Fig. 11 is a front view of a wheelchair with a leg rest assembly according to an aspect of the present invention;

Fig. 12 is a front view of a leg rest assembly according to an aspect of the present invention;

Fig. 13 is a side view of a leg rest assembly according to an aspect of the present invention;

Fig. 14A is a side view of a leg rest extension hub according to an aspect of the present invention; Fig. 14B is a side view of a leg rest extension hub according to an aspect of the present invention;

Fig. 15A is an exploded, partially cross-sectional view of a leg rest assembly according to an aspect of the present invention; Fig. 15B is an exploded, partially cross-sectional view of a leg rest assembly according to an aspect of the present invention;

Fig. 15C is an exploded, partially cross-sectional view of a leg rest assembly according to an aspect of the present invention;

Fig. 15D is an exploded, partially cross-sectional view of a leg rest assembly according to an aspect of the present invention;

Fig. 16 is an exploded, partially cross-sectional view of an extension hub member, a pair of gear washers, and a frame hub member according to an aspect of the present invention;

Fig. 17A is an exploded, partially cross-sectional view of a hub member and a gear washer according to an aspect of the present invention;

Fig. 17B is an exploded, partially cross-sectional view of a hub member and a gear washer according to an aspect of the present invention; and Fig. 18 is a partially cross-sectional side view taken along the section line 18-18 in Fig. 15 A of a handle assembly and a clamping rod according to an aspect of the present invention.

Detailed Description of the Preferred Embodiments With reference to Fig. 1 , a wheelchair 10 includes a molded, modular chassis 12 and two large drive wheels 14a and 14b attached to the chassis 12 by axles (not shown). Two swivel-mounted casters 16a and 16b are also attached to the chassis 12 in front of the drive wheels 14a and 14b, as better seen in Fig. 2. A seating system 20 is demountably attached to the chassis 12, e.g., by four mounting posts: two rear posts 22a and 22b (not shown) and two forward posts 24a and 24b which telescope upwardly from within the molded chassis structure 12.

The angle of the seating system 20 relative to the chassis 12

(and to the generally horizontal surface over which the wheelchair 10 is propelled) may also easily be adjusted by height adjustment of the forward posts 24a, 24b relative to the rear posts 22a, 22b.

Referring to Fig. 5, the seating system 20 includes a generally rectangular frame 34 formed of two longitudinal side extrusions 36a and 36b, and two cross-bars 38a and 38b, respectively, secured to the side extrusions at the front and rear of the frame 34. Two longitudinal mounting rails 40a and 40b extend downwardly from the side extrusions 36a and 36b. The rails 40a and 40b are preferably integrally formed with the side extrusions 36a and 36b, although the rails may be made separately and then secured, e.g. , by welding, to the undersides of the side extrusions 36a and 36b. The rail 40a is adjustably attached to the mounting posts 22a and 24a, and the rail 40b is adjustably attached to the mounting posts 22b and 24b. While there may be a virtually unlimited number of longitudinal attachment positions of the seating system 20 by the rails 40a, 40b, five positions are shown in Fig. 5 by virtue of transverse holes 42 defined through the rails 40a and 40b. In this manner, the center of gravity of the user may be easily adjusted relative to the chassis 12 and its fixed wheelbase between the drive wheels 14a, 14b and casters 16a, 16b. Referring to Figs. 1 and 4, the modular leg rest assembly 82 is pivotally mounted to the front cross-bar 38a of the seating system frame 34. The leg rest assembly 82 includes two tubes 84 and 86 which are connected along a common seam 87. Two compression clamps 88 and 90, respectively, attach the tubes 84 and 86 to the cross-bar 38a. The compression clamps 88 and 90 are compressed and released by operation of a common actuation lever 92. Rotation of the lever 92 causes the clamps 88 and 90 to lock the leg rest assembly 82 at a desired position relative to the seating system 20 and the wheelchair 10 on which the seating system is installed and to be used.

In another aspect of the present invention shown in Fig. 11 , the wheelchair is provided with a leg rest assembly 182. The leg rest assembly 182, shown in front and side views in Figs. 12 and 13, normally includes two leg rest extensions 183a, 183b which may be identical to or mirror images of one another in terms of their attachment to the wheelchair frame 34 and which are connected to each other by foot rest member 301 , 302. The "a" designation denotes a left side, and the "b" designation denotes a right side of the wheelchair. The following discussion of the leg rest assembly will not distinguish between the leg rest extensions 183a, 183b, except as otherwise noted. For example, it will be appreciated by one skilled in the art that the discussion of a leg rest extension 183 describes the leg rest extensions 183a, 183b.

The leg rest extension 183 includes an extension hub member 186 at the top end 184 of the leg rest extension. A front view and a side view of the extension hub member 186 are shown in Figs. 14A and 15D, respectively. The extension hub member 186 is provided with projections 187 for interengagement with corresponding projections 211 on a frame hub member 210 on a portion of the wheelchair frame 34. Frame hub members 210a, 210b on the wheelchair frame 34 are shown in Fig. 11. By engaging and disengaging the projections for interengagement between respective extension hub members 186 and frame hub members 210, it is possible to adjust the angle of the leg rest extension 183 relative to the wheelchair frame 34. A preferred shape of the projections 187 for interengagement is that of a series of radial serrations 204, as shown in Figs. 14A and 14B.

As can be seen in Figs. 15A-D, the extension hub members 186 and the frame hub members 210 are provided with bores 203, 212, respectively, through the centers of the hubs for receiving a clamping rod 201. The projections 187, 211 of the hub members 186, 210 are engaged and disengaged by the action of a clamping handle assembly 202 attached at one end of the clamping rod 201 that causes the hub members 186, 210 to be drawn together when the rod 201 is pulled to one position by the clamping handle assembly, or to be allowed to move away from one another when the rod is in another position. The clamping rod 201 and clamping handle assembly 202 are preferably a quick-release mechanism. In such a mechanism, shown in Figs. 11 , 12, 13, 15A-15C, and 18, the clamping handle assembly 202 might include a bushing 400, shown in

Fig. 18, that is receivable in a bore 401 and rotatable relative to a handle 402 formed with a cammed surface 403. The handle is further formed with a slot 404 through which a threaded end of the clamping rod 201 is passed to screw into a threaded bore 405 in the bushing 400. The handle 402 is pivotal relative to the bushing 400 and the clamping rod 201 such that an enlarged portion of the cammed surface 403 can be moved between the bearing and a hub surface S to clamp the extension hub member 186 and the frame hub member 210 together. When the extension hub member 186 and the frame hub member 210 are moved away from one another by pivoting the handle 402 such that a narrower portion of the cammed surface is between the bearing and a hub surface, as shown in Fig. 18 by dashed lines, it is possible to adjust the angle of the leg rest extension relative to the wheelchair frame 34.

While the extension hub member 186 may be a separate piece attached to a top end 184 of the leg rest extension 183, as shown in Figs. 15A, 15C, and 15D, it may also be formed with the leg rest extension as a single integral piece, as shown in Fig. 15B. In Figs. 15A and 15C, the top end 184 of the leg rest extension 183 may be fitted within a recess 206 for receiving the top end 184 in the extension hub member 186. As shown in Fig. 15C, the clamping rod 201 may extend through a bore 207 in the top end 184 of the leg rest extension 183. Alternatively, the top end of the leg rest extension may be secured to the extension hub member by a tight fit or adhesive, or other fastening means, as shown in Fig. 15A. The extension hub member 186 may further be provided with a projection 208, as shown in Fig. 15D, for being received in a tubular top end of the leg extension.

While the projections for interengagement may be formed directly on the extension hub member 186, as shown in Fig. 15D, the extension hub member 186 may, instead, comprise a gear washer 188 having projections 187 for interengagement on one side 189 of the gear washer. The gear washer 188 is received in a washer receptacle 191 as shown in Figs. 15A-C. The washer receptacle 191 includes lands 192 to properly align the gear washer 188 in the washer receptacle. Similarly, frame hub member 210 may comprise a separate gear washer 213 that has a side with projections 211 for interengagement. The frame hub member 210 includes a gear washer receptacle 216 and lands 217 for receiving the gear washer. This latter construction permits replacement of a small gear washer 188 or 213, if necessary, rather than replacement of an entire extension hub member 186 or frame hub member 210, or leg rest extension 183 or frame 34.

As shown in Figs. 14A-B and 15A-D, one of the gear washers 188 may be formed to include a circumferential lip portion 193 of sufficient size to receive the diameter of the other gear washer 213 having projections for interengagement. Thus, when the gear washers 188, 213 are disengaged, the projections 187, 211 for interengagement are not exposed, and the likelihood of undesirable events such as snagging of the projections on loose clothing or damage to the projections from stray particles becoming trapped between the gear washers 188, 213 is lessened.

In the extension hub member 186, the washer receptacle

191, and the interfacing side 190 of the gear washer 188 may be any desired interfacing shape, such as generally flat, shown in Figs. 15 A and 15C, or generally spherical or semi-spherical, shown in Figs. 15B, 16, and 17A, or some combination of flat and spherical or semi-spherical, as shown in Fig. 17B. However, the gear washer 188 should not be readily rotatable relative to the washer receptacle 191. To this end, the bottom 200 of the washer receptacle 191 and the interfacing side 190 of the gear washer 188 may be provided with slot 196 and tab 197 arrangements, as shown in Fig. 16, or projection 194 and projection receiving recess 195 arrangements, as shown in Figs. 15A and 15C, or formed in any desired manner, such as a V-shape and a V-shaped groove (not shown), to create an interlocking effect. The gear washer receptacle 216 of the frame hub member 210 and an interfacing side 215 of the hub gear washer 213 may also be provided with slot 220 and tab 221 arrangements, or projection 218 and projection receiving recess 219 arrangements in the same way as the extension hub member 186. See Figs. 15A-D, 16 and 17A-B.

The gear washer 188 should be secured within the washer receptacle 191 in a manner that ensures engagement of the projections 187 for interengagement with corresponding projections 211 for interengagement on the frame hub gear washer 213 under all operating conditions, especially those conditions that may initiate bending forces through the coupling of those projections. For example, manufacturing tolerances may lead to a situation where the span of the footrest member 301 , 302 (Fig. 11) is either greater or less than the actual distance between the leg rest extensions 183a, 183b. In the event the span is greater, a force will be initiated that will urge the extensions 183a, 183b to pivot around the hub 186 in a clockwise and counterclockwise direction, respectively. In the event the span is less, a force will be initiated that will urge the extensions 183a, 183b to pivot around the hub 186 in opposite directions, respectively. These potential forces are depicted with arrows in Fig. 12. To accommodate any actual pivoting movement of the leg extensions relative to the hub, the receptacle 191 and the gear washer 188 may be formed with aligned radial bores 198 and 199 through which a pin 205 extends through the hub 186 to secure the gear washer within the receptacle, as shown in Figs. 12 and 14B. In this way, the gear washer 188 is allowed to pivot around the pins 205 and therefore automatically adjust for any pivoting movement of the leg rest extensions while also ensuring engagement of the projections of the gear washers. The bores 198 and 199 and the pin 205 will, of course, also prevent rotation of the gear washer 188 relative to the receptacle 191 and ay be used for that purpose as an alternative to or in addition to the previously described structures for preventing rotation of the gear washer relative to the base. Another method for accommodating any pivoting movement of the leg rest extensions 183a, 183b is to configure the gear washer 188 with a spherical surface, as shown in Fig. 15B. As with the pins 205, the spherical surface allows the gear washer to float in such a manner as to allow for pivoting movement while also ensuring constant engagement of the projections.

The leg rest extension 183 may be tubular, as shown in Figs. 15A and 15D, or solid, as shown in Figs. 15B and 15C. As shown in Fig. 15D, the extension 183 is provided with openings 300 passing through the extension for attachment of a foot rest assembly to each extension. Telescoping foot rest member 301 , 302 with apertures 303 is attached to the bottom 185 of the leg rest extension 183 at desired heights by pins (not shown). The foot rest member 301 , 302 is preferably received inside of tubular leg rest extensions 183; however, the foot rest member 301 , 302 may also be tubular, and the tubular or solid leg rest extension 183 may be received within the foot rest member (not shown).

The foot rest member 301 , 302 may be attached at bottom portions thereof to individual foot rests (not shown). However, the foot rest shafts may also be connected to one another such that the leg rest assembly 182 is angularly adjustable relative to the frame 34 only as a ^' single piece, as shown in Fig. 11.

Referring to Fig. 4, two footrest shafts 94 and 96 coaxially telescope along an upward locus within the tubes 84 and 86, respectively. As will be recognized by those skilled in the art, a single tube having two interior races may be used to accommodate the telescoping shafts 94 and 96. The footrest shafts 94 and 96 may be set independently at progressively stepped heights by virtue of apertures 95 and transverse locking pins (not shown) passing through a selected opening 85 through the corresponding tubes 84 and 86. Alternatively, the tube position for the selected height may be set with a conventional clamp such as ring clamp, as shown in Fig. 10.

A right laterally extending footrest 98 is secured at an inner end of the shaft 94 and is thereby positioned by adjustable extension of the shaft 94. An outer support cable 100 attaches between a lateral end of the right footrest 98 and a right side extrusion 36a of the seating system (shown on the left side of the front elevation drawing of Fig. 1) and also permits height adjustments to be made to the right footrest 98. A left footrest 102 is secured to an inner end of the shaft 96 and is also thereby positioned by adjustable extension of the shaft 96 relative to the tube 86. A lateral support cable 104 attaches between an outer end of the left footrest 102 and the left side extrusion 36b of the frame 34. The outer cable 104 also permits height adjustments to be made to the left footrest 102 which are independent of the height adjustments made to the right footrest 98, as suggested by differing footrest heights shown in Fig. 3. The outer cables are constructed of an elastic material and are maintained under tension to provide axial alignment support to the outer ends of the footrests. Alternatively, the outer cables may be a rigid material, such as a rigid metal cable, or the outer cables may be telescoping tubes (as shown in Fig. 10) maintained under tension with a spring or elastic cord. A leg support sling 106, formed of a suitable webbed or non- woven fabric material, is loosely and adjustably suspended across the outer support cables 100 and 104 to enable the user's calves to be conveniently and comfortably supported.

Referring to Fig. 5, the angle of the entire leg rest assembly 82 may be easily adjusted by partially releasing the clamps 88 and 90 with the clamping control lever 92 and thereupon rotating the leg rest assembly 82 relative to the frame 34. The leg rest assembly 82 may be incrementally rotated relative to the frame 34 throughout the range of motion from point a to point c. At point a, the user's legs and knee joints are fully extended. At point b, the user's knees are at a 90 degree angle. At point c, the wheelchair may be stored by positioning the leg rest assembly 82 behind the frame 34 in order to facilitate entry and exit from the wheelchair. The pivot attachment of the leg rest assembly 82 enables a therapeutically determined knee angle for the user to be preselected and maintained. When the desired angle is reached, the clamping control lever 92 is manipulated simultaneously to tighten the clamps 88 and 90.

Either footrest 98 or 102 may be removed from its corresponding outer tube 84 or 86 by removal of the inner shaft 94 or 96 and disconnection of the support cable 100 or 104, as the case may be for a single amputee. To accommodate double amputees, the entire leg rest assembly 82 may be removed from the seating system frame 34 upon full release of the clamps 88 and 90 and removal of the tubes 84 and 86. Partial release of the clamps enables the leg rest assembly to be folded under the seating system frame 34 after the seating system 20 has been disconnected from and removed from the wheelchair chassis, as shown in Fig. 5. This arrangement enables the entire seating system 20 including the seat frame 34, back rest 50 and leg rest 82 to be nested together for storage or convenient transportation as in the overhead luggage compartment of an airplane.

In another aspect of the present invention shown in Figs. 6 and 7, a single vertical tube 83 is pivotally mounted to the front cross-bar 38a of the seating system to define the leg rest 82' . Compression clamps attach the single, extensible tube 83 to the cross-bar 38a, as described above. A single footrest shaft 93 is secured at an inner end of the tube 83 and is positioned by extending the tube 83. The transversely aligned footrest 102' defines forwardly positioned protrusions which terminate in bumper knobs 99. The knobs 99 may be formed from rubberized materials which protect the feet and which enable the user to push against doors or other objects. The footrest 102' is elliptically shaped to enable the user's feet to be positioned fore and aft to select a therapeutic ankle angle. The range of ankle positions may thereby be adjusted in conjunction with a selected knee angle selected by adjusting the compression clamps.

In still another aspect of the footrest of the present invention as shown in Figs. 8 A and 8B, the leg rest assembly 82 is shown having pivotally attached footrests 98' and 102'. The selected length of each footrest shaft 94 and 96 is secured within tubes 84 and 86 using a clamp 94'. The footrests 98' and 102' are pivotally secured to shafts 94 and 96 with locking bolts 960. The bolts pass through holes in the shafts 94 and 96 and through threaded holes in the footrests 98' and 102' . The pivoting footrests are locked into the selected position by tightening the bolts, thereby enabling the user's ankle angle to be independently adjusted, or to be adjusted in conformity to the selected knee angle. In yet another aspect of the present invention shown in Fig. 9, a leg rest assembly 82 is shown having one U-shaped tube 84' which attaches to an adjustable footrest shaft 96'. The legs of the "U" descend to define two lateral arms. The curved footrest shaft 96' may be adjustably moved upwardly and downwardly within the arms of the tube 84', and further telescopes laterally within the footrest 98' in order to conform to the upward and downward movement. The lateral arms are particularly suitable for protection against impact from the side during sports events, and further provide convenient hand support positions to ease transfers from a floor position into the chair.

Although the presently preferred embodiments of the invention have been illustrated and discussed herein, it is contemplated that various changes and modifications will be immediately apparent to those skilled in the art after reading the foregoing description in conjunction with the drawings. Accordingly, it is intended that the description herein is by way of illustration and should not be deemed limiting the invention, the scope of which being more particularly specified and pointed out by the following claims.

Claims

WHAT IS CLAIMED IS:

1. An angularly adjustable leg rest assembly for a wheelchair, comprising: a leg rest extension having a top and a bottom end; an extension hub member positioned at the top end of the leg rest extension; a frame hub member also positioned at the top end of the leg rest extension; said extension hub member having projections for interengagement with said frame hub member; and means for engaging and disengaging said projections for interengagement of said extension hub member with said frame hub member at various angular relationships.

2. An angularly adjustable leg rest assembly for a wheelchair as set forth in Claim 1 , wherein said extension hub member includes a gear washer, a gear washer receptacle and means for preventing rotation of said gear washer relative to said receptacle; one side of said gear washer being formed with said projections for interengagement; and said means for preventing rotation of said gear washer relative to said receptacle being disposed in said receptacle.

3. An angularly adjustable leg rest assembly for a wheelchair as set forth in Claim 2, wherein said gear washer is formed with a circumferential lip portion extending beyond said projections for interengagement.

4. An angularly adjustable leg rest assembly for a wheelchair as set forth in Claim 2, wherein said means for preventing rotation comprises a tab on said gear washer and a tab receiving slot in said receptacle.

5. An angularly adjustable leg rest assembly for a wheelchair as set forth in Claim 2, wherein said means for preventing rotation comprises a tab in said receptacle and a tab receiving slot in said gear washer.

6. An angularly adjustable leg rest assembly for a wheelchair as set forth in Claim 2, wherein said means for preventing rotation comprises a plurality of projections on said gear washer and a corresponding plurality of projection receiving recesses in said receptacle.

7. An angularly adjustable leg rest assembly for a wheelchair as set forth in Claim 2, wherein said means for preventing rotation comprises a plurality of projections in said receptacle and a corresponding plurality of projection receiving recesses in said gear washer.

8. An angularly adjustable leg rest assembly for a wheelchair as set forth in Claim 2, further comprising means for accommodating pivoting movement between said extension hub member and said frame hub member.

9. An angularly adjustable leg rest assembly for a wheelchair as set forth in Claim 8, wherein said receptacle includes a radial bore extending from an outer surface of said receptacle to an inner surface of said receptacle, and said gear washer includes a radial bore, and said means for accommodating pivoting movement comprises a pin extending through said radial bore in said receptacle and said radial bore in said gear washer.

10. An angularly adjustable leg rest assembly for a wheelchair as set forth in Claim 8, wherein said means for accommodating pivotal movement includes mating spherical surfaces of said receptacle and said gear washer.

11. An angularly adjustable leg rest assembly for a wheelchair as set forth in Claim 2, wherein a side of the gear washer opposite said projections has a generally semi-spherical shape.

12. An angularly adjustable leg rest assembly for a wheelchair as set forth in Claim 11 , wherein the bottom of said receptacle has a generally semi-spherical shape to receive said opposite side of said gear washer.

13. An angularly adjustable leg rest assembly for a wheelchair as set forth in Claim 1 , wherein said extension hub member and said frame hub member each include a bore passing substantially through the center of said extension hub member and said frame hub member, and wherein a clamping rod extends through the bore in said hub members, said clamping rod being attached at one end to a clamping handle whereby movement of said clamping handle causes movement of said clamping rod to engage and disengage said projections.

14. An angularly adjustable leg rest assembly for a wheelchair as set forth in Claim 13, wherein said extension hub member is detachable from said leg rest extension.

15. An angularly adjustable leg rest assembly for a wheelchair as set forth in Claim 1 , wherein said projections for interengagement are shaped as a plurality of radial serrations.

16. An angularly adjustable leg rest assembly for a wheelchair, comprising: a leg rest extension having a top and a bottom end; an extension hub member positioned at the top end of said leg rest extension; a frame hub member positioned at the top end of said leg rest extension, each of said hub members having projections for interengagement with each other; and means for engaging and disengaging said projections for interengagement of said hub members at various angular relationships.

17. An angularly adjustable leg rest assembly for a wheelchair as set forth in Claim 16, wherein said extension hub member and said frame hub member each have a center bore and said means for engaging and disengaging includes a clamping rod extending through said bore, said clamping rod being attached at one end to a clamping handle, such that movement of said clamping handle causes movement of said clamping rod to engage and disengage said projections.

18. An angularly adjustable leg rest assembly for a wheelchair as set forth in Claim 16, wherein said extension hub member includes a gear washer, a washer receptacle, and means for preventing rotation of the gear washer relative to the receptacle, said projections for interengagement being disposed on one side of said gear washer.

19. An angularly adjustable leg rest assembly for a wheelchair as set forth in Claim 18, wherein said gear washer is formed with a circumferential lip portion extending beyond said projections for interengagement such that projections for interengagement of said frame hub member are positionable within said lip portion when said projections of said hub members are engaged and when said projections of said hub members are disengaged.

20. An angularly adjustable leg rest assembly for a wheelchair as set forth in Claim 19, wherein said frame hub member includes a gear washer, a washer receptacle, and means for preventing rotation of the second hub gear washer relative to the hub receptacle, said projections being disposed on one side of said gear washer.