WO2013052778A1

WO2013052778A1 - Power module for a wheelchair

Info

Publication number: WO2013052778A1
Application number: PCT/US2012/058920
Authority: WO
Inventors: Marvin J WACHENDORF; Anthony J. MATTIO
Original assignee: Simun Usa, Llc
Priority date: 2011-10-06
Filing date: 2012-10-05
Publication date: 2013-04-11

Abstract

An electric power module, detachably attachable to a conventional wheelchair, selectively provides power through a driver wheel to move the wheelchair. A lever lowers and raises the power module to place the wheel into and out of contact with the underlying surface. A twist grip or handle on the lever controls the rate of rotation of the wheel and the speed of the wheelchair.

Description

POWER MODULE FOR A WHEELCHAIR

CROSS REFERENCE TO RELATED APPLICATION

The present application includes subject matter disclosed in and claims priority to a provisional application entitled "Retractable Powered Wheel Attachment for Manual

Wheelchairs" filed October 6, 2011 and assigned Serial Number 61/544,038 describing an invention made by the present inventors.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to mountable and dismountable power modules for wheelchairs selectively engageable to provide motion to the wheelchair.

2. Description of Related Prior Art

Traditionally, wheelchairs are used by persons who may not be sufficiently ambulatory or who may be prone to losing their balance when walking. Often, wheelchairs are used by those suffering temporary or permanent injury to one or both legs, hips, or back.

Forward and backward motion of the wheelchair may be established by a third person pushing the wheelchair by gripping handles at the rear. More often, the wheelchair is moved forward or backward by pushing on circular rails affixed to the main wheels. A pair of pivotable wheels are mounted at the front to establish a four-point platform that is relatively stable. Additionally, these pivotable wheels accommodate a change of direction by rotating one of the main wheels differently from that of the other main wheel.

From an understanding of the operation of a wheelchair, it is apparent that a user must have a certain amount of strength in his/her arms in order to cause rotation of the main wheels. On a horizontal surface, the degree of strength required is relatively small to provide a slow rate of movement of the wheelchair. If an upward incline is encountered, a significantly greater degree of strength in a user's arms is required. Similarly, if a downward incline is encountered, significant braking force on the main wheels may have to be exerted to prevent runaway movement.

Electrically powered wheelchairs are well-known and have been used for many years. These wheelchairs include batteries of the automotive type which are relatively heavy. The batteries operate an electric motor of significant power and weight to cause motion of the main wheels via a transmission.

One of the main benefits of a conventional wheelchair is that it is collapsible. In the collapsed state, the wheelchair is often transported in the trunk or backseat of a sedan. Because the conventional wheelchair is relatively lightweight, lifting it into and out of a vehicle is relatively easy. Additionally, the wheelchair may be stored in a relatively small place in a user's home or other abode. Electrically powered wheelchairs are not collapsible. Additionally, electric powered wheelchairs are heavy and too heavy to be lifted by a reasonably healthy person. To transport an electric wheelchair, a rack must be attached to the rear of a vehicle and include a ramp for moving the electric wheelchair onto and off of the rack. Generally, the user of such a wheelchair is not capable of performing these chores due to health conditions or reduced strength. Moreover, an electrical wheelchair requires a lot of floor space in a user's home or other abode. There is also the problem of moving an electric wheelchair over the threshold of the entry door or up steps, if present.

SUMMARY OF THE INVENTION

An electric power module is detachably attachable to certain frame members of a conventional wheelchair. The power module is selectively engageable with the ground or other surface being traversed by the wheelchair. The power module includes an electric motor connected through a transmission to a driving wheel. By repositioning the power module, the wheel is selectively in contact with the ground or other surface being traversed. A twist handle, that may be operated by either the left or right hand, controls the speed of rotation of the wheel and hence the speed of movement of the wheelchair. The power may be provided by a conventional electric drill or a conventional electric motor.

It is therefore a primary object of the present invention to provide a power module as a motive means for a conventional wheelchair.

Another object of the present invention is to provide a power module detachably attached to the frame of a conventional wheelchair.

Still another object of the present invention is to provide a power module selectively engageable with the surface being traversed to use or not use motive means for movement of the wheelchair. Yet another object of the present invention is to provide a speed control useable by either hand of an occupant of the wheelchair.

A further object of the present invention is to provide a pivotable lever of a power module for a wheelchair that enhances ease of ingress and egress.

A still further object of the present invention is to provide a powered wheelchair that is relatively lightweight.

A still further object of the present invention is to provide a method for adding motive means to a conventional wheelchair.

These and other objects of the present invention will become apparent to those skilled in the art as the description thereof proceeds.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described with greater specificity and clarity with reference to the following drawings, in which:

Figure 1 illustrates a side view of a conventional wheelchair and the power module mounted thereon with the near main wheel not shown for purposes of clarity;

Figure 2 is a side view of a conventional wheelchair having a power module mounted thereon and without showing the main wheels for purposes of clarity;

Figure 3 illustrates a front view of a portion of a wheelchair having the power module mounted thereon;

Figure 4 is similar to Figure 3 but the housing and axle has been deleted for purposes of clarity;

Figure 5 illustrates the power module prior to mounting on a wheelchair; Figure 5A illustrates a variant of the grip;

Figure 6 illustrates an alternative power module prior to being mounted on a wheelchair; Figure 7 illustrates an adjustment feature for mounting the power module;

Figure 8 illustrates a variant clamp mechanism for attaching the power module to a wheelchair;

Figure 9 illustrates the locking mechanism attendant the power module;

Figure 10 illustrates the lever and hand grip for gripping the power module during use; and

Figure 11 illustrates attachment of the power module to the frame of a wheelchair.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to Figure 1, there is shown a partial view of a conventional wheelchair 10. For clarity of illustration of the present invention, the right main wheel and supporting components have been omitted from Figure 1. A conventional wheelchair generally includes a tubular framework 12 defining a pair of tubular horizontal rails 14 below the seat that extend forwardly and downwardly to support a footrest 16. Additionally, they may support a backrest 26. Further tubular elements 18 interconnect with downward extension of rails 14 and support a pair of pivoting wheels 20, 22. Additionally, other tubular elements of framework 12 support a seat and an axle (which may be exposed or within a housing 100) for main wheels 28 and 29 (see Figure 3). As is well known, various hinge mechanisms may be incorporated to permit collapsing or folding the wheelchair into a relatively narrow unit.

Figure 2 illustrates part of tubular framework 12 but absent the wheels of wheelchair 10 to more clearly illustrate power module 30 and its components. These components will be described with joint reference to Figures 1 and 2. The power module includes a frame 32 pivotally attached to horizontal rails 14 extending along opposed sides of wheelchair 10. A power unit 34 is of the type described and illustrated in United States Patent No. 7,588,109, which patent is incorporated herein by reference. In this embodiment, the power unit includes an electric hand drill 36 detachably mounted on a base 38. The power unit urges rotation of a sprocket 40 through a transmission 42. The sprocket is connected to a further sprocket 44 associated with drive wheel 46 by a chain 48. Upon activating electric hand drill 36, rotary motion is imparted to drive wheel 46. It may be noted that the electric hand drill is shown disengaged from base 38 in Figure 2. Further details attendant electric hand drill 36, base 38 and transmission 42 are described in U.S. Patent No. 7,588,109 and incorporated herein by reference.

To prevent rearward tipping of the wheelchair upon aggressive acceleration, a rear wheel 47 may be added. It is supported by a beam 49 attached to and extending from frame 32.

Referring jointly to Figures 3, 4 and 5, details attendant power module 30 will be described. Frame 32 includes two essentially identical members 50, 52 separated from one another and joined by spacers 54, 56 and 58. A bracket 60 is supported by members 50, 52 and base 38 is attached thereto by conventional means. An axle 62 is attached to members 50, 52 and supports wheel 46 and its attached sprocket 44. A bar 70 extends through and from opposite sides of frame 32. It includes a first telescoping rod 72 that may be positionally clamped with clamp 74. A further telescoping rod 76 extends from bar 70 and may be positionally clamped with clamp 78. A pair of strap-type clamps 80, 82 are disposed at the terminal end of rod 72 for engagement with rail 14 of wheelchair 10, as shown in Figures 3 and 4. Similar strap-type clamps 84, 86 are disposed at the terminal end of rod 76 for engaging the opposed rail 14 of wheelchair 10, as shown in Figures 3 and 4. A lever 90 is rigidly attached to frame 32 to effect pivotal motion of the frame about bar 70 to raise and lower wheel 46. The lever includes a twist hand grip 92 for controlling the speed of rotary motion of power unit 34. This is effected in the conventional manner through a sheathed cable 94 attached to trigger 96 of electric hand drill 36. Alternatively, a conventional hand brake 98 may be pivotally attached to lever 90 for effecting translation of cable 94 in the manner of a brake for a bicycle or motorcycle, as shown in Figure 5A.

As noted in Figure 3, electric hand drill 36 is not shown and only base 38 extends from frame 32. Figure 4 is similar to Figure 3 except that housing 100 (or axle) shown in Figure 3 for an axle supporting wheels 28, 29 has been omitted for purposes of clarity. Additionally, the power unit has also been omitted.

Referring to Figure 6, there is shown a variant of power module 30. In this variant, an electric motor 110 of a conventional type, is supported by bracket 60 extending from members 50, 52 of frame 32. It includes a sprocket 112 for causing rotation of sprocket 44 and wheel 46 via chain 48. Necessarily, electric motor 110 requires a battery for operation. Such a battery may be mounted anywhere on wheelchair 10 that is convenient and at a location that does not interfere with normal operation of the wheelchair or frame 32. The power exerted by the electric motor may be controlled by twist hand grip 92 or a pivotable lever through cable 94 attached to a rheostat or other circuitry adapted to control the speed of rotation of the electric motor and hence control the speed of rotation of wheel 46.

Referring jointly to Figures 7 and 8, the apparatus for clamping power module 30 to the horizontal rails 14 of a wheelchair will be described in further detail. While only the right side clamping elements are described, the left side is structurally and functionally similar. Rod 72 is in slidable engagement with bar 70 to accommodate different widths between the horizontal rails of a wheelchair. Once the appropriate width is determined, clamp 74 is tightened to prevent slidable engagement between rod 72 and bar 70. The bar is secured to a rail by strap-type clamps 80, 82. These clamps may be supported upon a fitting 88 attached to and extending from rod 72. Conventional bolts and nuts may be used to attach the strap-type clamps to fitting 88, as illustrated in Figure 7. It is to be understood that other strap-type clamps could also be used for this purpose.

Figure 8 illustrates another embodiment of a mechanism for attaching bar 70 to each of opposed rails of the wheelchair. As illustrated, a block 120 is attached to the end of rod 72. This block includes a cylindrical indentation 122 generally matching in radius the rail of the wheelchair. A second block 124 also includes a cylindrical indentation 126. As particularly shown in Figure 8 A, block 124 is secured to block 120 by machine screws 128 to clamp the rail of the wheelchair within cylindrical indentations 122, 126.

Referring jointly to Figures 9, 10 and 11, the operation and apparatus attendant raising and lowering frame 32 will be described. An assembly 130 supported between members 50, 52 and actuated by lever 90 is, in effect, an overcenter lock mechanism for locking frame 32 in the retracted or upper position. It includes a bushing 132 mounted on bar 70 and secured to member 52 by machine screws 134 or the like. A similar bushing 138 is supported on bar 72 and attached to member 50 by machine screws 140 or the like. A further bushing 146 is supported on bar 70 and rotationally affixed thereto by a set screw 148. A first bracket 150 is disposed intermediate bushings 132, 146 and penetrably mounted on bar 70. A similar second bracket 152 is disposed intermediate bushings 146 and 138 in rotatable engagement with bar 70. First and second brackets 150, 152 are attached to an arm 154 by conventional bolts and nuts, of which bolt 156 is representatively illustrated. Arm 154 is attached to lever 90. A pair of tangs 160, 162 are supported by spacer 54. These tangs selectively engage lips 166, 168 in arm 154 to lock frame 32 in the raised position. It is to be understood that other structurally or functionally related overcenter lock mechanisms could be used.

By pushing forwardly on lever 90, frame 32 pivots upwardly about bar 70 and the overcenter lock is engaged to maintain the frame in the raised position. To lower frame 32 to have wheel 46 contact the ground or surface being traversed, lever 90 is pulled rearwardly to release the overcenter lock mechanism and let frame 32 pivot downwardly. It is to be noted that the forward motion of wheel 46 under urging by the respective electric power unit, creates a downward force on frame 32 to maintain the wheel in contact with the surface being traversed. For slippery surfaces, a rearward force on the lever by a user will enhance the pressure of wheel 46 on the surface being traversed.

To assist a user of wheelchair 10 get in and out of the wheelchair, lever 90 is pivotable downwardly to place it out of the way. Such selective pivotal motion is achieved by a conventional rotary locking hinge interconnecting lever 90 with arm 154. In particular, a knob 170 supports a threaded shaft for threadedly engaging a passageway in end 172 of lever 90. Thereby, end 172 will be drawn toward end 174 of arm 154 to ftictionally lock the two together at a selected angle between the longitudinal axis of lever 90 and arm 154.

Claims

I CLAIM:

1. A power module detachably attachable to a conventional wheelchair, said power module comprising:

(a) a frame detachably attachable to elements of the wheelchair;

(b) a power unit secured to said frame;

(c) a wheel connected to said power unit and supported by said frame;

(d) a lever extending from said frame for pivoting said frame to place said wheel into and out of contact with an underlying surface; and

(e) a manually operated device for controlling the speed of rotation of said wheel.

2. The power module as set forth in Claim 1 wherein said power unit includes an electric hand drill and a transmission interconnecting said hand drill with said wheel.

3. The power module as set forth in Claim 1 wherein said power unit includes an electric motor and a transmission interconnecting said electric motor with said wheel.

4. The power module as set forth in Claim 1 including a bar extending from opposed sides of said frame for engaging the elements of the wheelchair.

5. The power module as set forth in Claim 4 wherein the elements of the wheelchair include a pair of rails extending fore and aft along the sides of the wheelchair and including a clamp disposed at each end of said bar for engaging respective ones of said rails.

6. The power module as set forth in Claim 5 wherein said bar includes a telescoping member on either side of said frame for accommodating the width between the pair of rails.

7. The power module as set forth in Claim 4 wherein the elements of the wheelchair include a pair of rails extending fore and aft along the sides of the wheelchair and wherein said bar includes a telescoping member on either side of said frame for accommodating the width between the pair of rails.

8. The power module as set forth in Claim 1 including a trailing wheel attached to and extending rearwardly of said frame.

9. The power module as set forth in Claim 1 wherein said wheel includes a sprocket, said power unit includes an output sprocket and including a chain interconnecting said sprocket and said output sprocket for transmitting power from said power unit to said wheel.

10. The power module as set forth in Claim 4 wherein said frame is rotatably secured to said bar to accommodate pivotal movement of said frame to raise and lower said wheel.

11. The power module as set forth in Claim 10 including a lock mechanism for positionally locking said frame in a raised position.

12. The power module as set forth in Claim 3 including a mounting for attaching said electric motor to said frame.

13. The power module as set forth in Claim 12 wherein said wheel includes a sprocket, said electric motor including an output sprocket and a chain interconnecting said output sprocket with said sprocket for transmitting power from said electric motor to said wheel.

14. A method for moving a conventional wheelchair across a surface, said method comprising:

(a) rotating a frame pivotally attached to the wheelchair with a lever extending from the frame to bring a wheel supported at one end of the frame into contact with the surface;

(b) urging rotation of the wheel upon energizing a power unit attached to the frame; and

(c) causing said step of urging with a variable manually operated switch mounted on the lever.

15. The method as set forth in Claim 14 including the step of transmitting power from the power unit to the wheel with a transmission.

16. The method as set forth in Claim 15 including the step of moving the lever forwardly to facilitate ingress and egress into and out of the wheelchair.

17. A power module detachably attachable to a conventional wheelchair, said power module comprising:

(a) a frame pivotally attached to opposed rails of the wheelchair;

(b) an electric power unit supported on said frame;

(c) a wheel extending from said frame for selectively contacting the surface being traversed by the wheelchair upon pivotal movement of said frame;

(d) a transmission interconnecting said power unit with said wheel for urging rotation of said wheel and rolling movement of the wheelchair; and

(e) a switch for controlling operation of said power unit.

18. The power module as set forth in Claim 17 including a manually operated lever extending from said frame for controlling the pivotal movement of said frame to position said wheel in and out of contact with the surface.

19. The power module as set forth in Claim 18 including a trailing wheel extending from said frame.

20. The power module as set forth in Claim 19 including a bar for locating said frame generally at a mid-point between the rails of the wheelchair.

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