IPC분류정보
국가/구분 |
United States(US) Patent
등록
|
국제특허분류(IPC7판) |
|
출원번호 |
UP-0445366
(2006-06-02)
|
등록번호 |
US-7665754
(2010-04-09)
|
발명자
/ 주소 |
|
대리인 / 주소 |
|
인용정보 |
피인용 횟수 :
1 인용 특허 :
4 |
초록
▼
A propulsion unit for a wheelchair wheel with a track. The propulsion unit comprising a body having a front portion, a rear portion and a handle, at least three rollers pivotally mounted to the body, front and rear friction elements positioned in the front and rear portions of the body respectively.
A propulsion unit for a wheelchair wheel with a track. The propulsion unit comprising a body having a front portion, a rear portion and a handle, at least three rollers pivotally mounted to the body, front and rear friction elements positioned in the front and rear portions of the body respectively. When the handle is pressed forward the wheel is propelled forward and when the handle is pressed rearward the wheel is propelled rearward.
대표청구항
▼
The invention claimed is: 1. A propulsion unit for a wheelchair wherein the wheelchair has a frame with a pair of large diameter wheels of the type having a track having an outer surface and an inner surface, the propulsion unit comprising: a body having a front portion, a rear portion and a handle
The invention claimed is: 1. A propulsion unit for a wheelchair wherein the wheelchair has a frame with a pair of large diameter wheels of the type having a track having an outer surface and an inner surface, the propulsion unit comprising: a body having a front portion, a rear portion and a handle; at least three rollers pivotally mounted to said body, two of said at least three rollers being spring biased and adapted to be mounted in contact with one of the inner and outer surfaces of the track, the remaining of said at least three rollers adapted to be mounted in contact with the other of the inner and outer surfaces of the track; front and rear friction elements positioned in said front and rear portions of said body respectively, said front friction element adapted to engage the track when a forward pressure is applied to said handle rocking said body forward, said rear friction element adapted to engage the track when a rearward pressure is applied to said handle rocking said body rearward; and wherein when the handle is pressed forward the wheel is propelled forward and when the handle is pressed rearward the wheel is propelled rearward. 2. The propulsion unit as defined in claim 1, further comprising a linking piece having a first end attached to said propulsion unit and a second end adapted for attachment to said frame of said wheelchair to maintain said propulsion unit in an easy to reach position for a wheelchair user, said linking piece preventing said propulsion unit from rolling forward or rearward off said track. 3. The propulsion unit as defined in claim 1, wherein said spring bias is provided by a spring urging said two of said at least three rollers against the track maintaining said front and rear friction elements away from the handrail, and wherein said spring flexes when said handle is pressed forward allowing said front friction element to engage the track and when said handle is pressed rearward allowing said rear friction element to engage the handrail. 4. The propulsion unit as defined in claim 3, wherein the spring is a leaf spring. 5. The propulsion unit as defined in claim 4, wherein said spring is in contact with said two of said at least three rollers extending therebetween, said spring being in contact at a distance from the track greater than a distance from the track to a center of rotation of said two of said at least three rollers. 6. The propulsion unit as defined in claim 5, wherein said spring is fixed to said body at a fixation point thereof. 7. The propulsion unit as defined in claim 6, wherein said fixation point may be one of equidistantly spaced and off-center between said two of said at least three rollers. 8. The propulsion unit as defined in claim 1, wherein said at least three rollers are triangularly oriented. 9. The propulsion unit as defined in claim 8, wherein one of said at least three rollers is disposed in said front portion of said body, and another of said at least three rollers is disposed in said rear portion of said body. 10. The propulsion unit as defined in claim 1, wherein said body pivots about an axis of rotation of said remaining of said at least three rollers when rocked forwardly and rearwardly. 11. The propulsion unit as defined in claim 10, wherein said remaining of said at least three rollers is attached to said body by an axle bolt, said body pivoting about said axle bolt. 12. The propulsion unit as defined in claim 1, wherein said two of at least three rollers are each attached to said body by an axle bolt. 13. The propulsion unit as defined in claim 12, wherein said body defines two oblong slots, said axle bolts of said two of said at least three rollers extending through said oblong slots, and wherein said axle bolts are displaced in opposite directions in said oblong slots when pressure is applied to said handle. 14. The propulsion unit as defined in claim 1, wherein said spring bias is provided by a spring loaded carriage, said two of said at least three rollers being rotateably attached to opposite ends of said spring loaded carriage. 15. The propulsion unit as defined in claim 14, wherein said spring loaded carriage is fixed to said body at a fixation point. 16. The propulsion unit as defined in claim 15, wherein said fixation point may be one of equidistantly spaced and off-center between said two of said at least three rollers. 17. The propulsion unit as defined in claim 1, wherein said body has a side portion extending in a plane perpendicular to the wheel axis of rotation and a top portion extending perpendicular to said side portion adapted to extend over the outer surface of the track. 18. The propulsion unit as defined in claim 17, wherein said handle extends outwardly away from said top portion of said body. 19. The propulsion unit as defined in claim 17, wherein said remaining of said at least three rollers is axially fixed to said side portion by an axle bolt, said body pivoting about said axle bolt when rocked forwardly and rearwardly. 20. The propulsion unit as defined in claim 1, wherein said front and rear friction elements are provided as elastomeric pads. 21. In combination a propulsion unit and a track for a wheelchair wherein the wheelchair has a frame with a pair of large diameter wheels, said track comprising an outer surface and an inner surface and adapted to be fixed to one of said wheels and said propulsion unit grippingly engaged with said track, said propulsion unit comprising: a body having a front portion, a rear portion and a handle; at least three rollers pivotally mounted to said body, two of said at least three rollers being spring biased and mounted in contact with one of the inner and outer surfaces of the track, the remaining of said at least three rollers mounted in contact with the other of the inner and outer surfaces of the track; front and rear friction elements positioned in said front and rear portions of said body respectively, said front friction elements engaging the track when a forward pressure is applied to said handle rocking said body forward, said rear friction element engaging the track when a rearward pressure is applied to said handle rocking said body rearward; and wherein when the handle is pressed forward the wheel is propelled forward and when the handle is pressed rearward the wheel is propelled rearward. 22. The combination of claim 21, wherein said track has a circular cross-section and said rollers have a concave body section for mating engagement therewith. 23. The combination of claim 21, wherein said track has a first and a second groove on said inner and outer surfaces respectively and said rollers have a convex curvature for mating with said respective grooves. 24. The combination of claim 21, wherein said track and said propulsion unit comprise a mechanical grip including complementary members defined on said track and on said propulsion unit for mating engagement to impart force that is applied to said handle to said track and from said track to said wheel. 25. The combination of claim 24, wherein said mechanical grip is provided as protrusions on said friction elements respectively and complementary indentations on said outer surface of said track. 26. The combination of claim 24, wherein said mechanical grip is provided as corrugated surfaces on said friction elements respectively and a complementary corrugated surface on said outer surface.
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