Mechanical wheelchair drive and wheelchair having such a mechanical wheelchair drive
AssigneeTechnische Universitaet Wien
InventorsMargit Gfoehler, Nithin Babu Rajendra Kurup, Markus Puchinger
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Abstract
The invention relates to a mechanical wheelchair drive, comprising a rotatably mounted lever, a handle fastened to the lever, and a force transfer unit for transferring rotational motion of the lever to a wheelchair wheel, wherein the lever has a variable length and is guided along a closed guide of a guide plate, said guide deviating from the circular form, such that the length of the lever changes during the rotational motion.
Claims16
Mechanical wheelchair drive comprising a rotatably mounted lever, a handle fastened to the lever and a force transfer unit configured to transfer a rotational motion of the lever to a wheelchair wheel, wherein the lever has a variable length and can be guided along a closed guide of a guide plate, which guide deviates from the circular form, so that a length variation of the lever takes place during the rotational motion, wherein the guide corresponds to a droplet-shaped closed curve having a wide end curve region and a narrow end curve region, wherein the end curve regions each have a vertex point and the narrow end curve region of the closed curve in a mounted state of the wheelchair drive points in a direction towards a backrest of a wheelchair in a mounted state of the wheelchair drive, a longitudinal axis running between the vertex points of the wide end curve region and the narrow end curve region is inclined by at least 5° but no more than 30° with respect to the horizontal, and wherein the curve can be described by the following mathematical equations:
- X
- 1
- =
- A
-
- cos
-
- (
- θ
- )
- Y
- 1
- =
- B
-
- sin
-
- (
- θ
- )
-
- sin
- n
- (
- 0.5
- *
- θ
- )
- (
- X
- Y
- )
- =
- (
- cos
-
- (
- β
- )
- -
- sin
-
- (
- β
- )
- sin
-
- (
- β
- )
- cos
-
- (
- β
- )
- )
-
- (
- X
- 1
- Y
- 1
- )
- wherein θ corresponds to an angle, the coordinates X and Y describe the course of the guide in a Cartesian coordinate system, the parameter β is specified between −20° and 30°, the parameters A and B are specified between 0.01 m and 0.25 m and the parameter n is specified between 0.2 and 0.9.
A wheelchair, comprising:
- a seat surface;
- a backrest;
- a first wheelchair wheel and a second wheelchair wheel;
- a first mechanical wheelchair drive and a second mechanical wheelchair drive, wherein the first mechanical wheelchair drive is connected to the first wheelchair wheel and the second mechanical wheelchair drive is connected to the second wheelchair wheel, the first and second mechanical wheelchair drives each comprising a rotatably mounted lever, a handle fastened to the lever, and a force transfer unit for transferring a rotational motion of the lever to the first or second wheelchair wheel, respectively, wherein the lever has a variable length and can be guided along a closed guide of a guide plate, which guide deviates from the circular form, so that a length variation of the lever takes place during the rotational motion, wherein the guide is a closed loop in the form of a slot guide, and wherein a guide pin fastened to the lever is configured to be guided in the slot guide;
- and
- a first and a second horizontal adjusting device, the first horizontal adjusting device being configured to adjustably fasten the guide plate and the lever of the first mechanical wheelchair drive along a first horizontal in a first plane next to the seat surface and parallel to the first wheelchair wheel, the second horizontal adjusting device being configured to adjustably fasten the guide plate and the lever of the second mechanical wheelchair drive along a second horizontal in a second plane next to the seat surface and parallel to the second wheelchair wheel.
Dependencies are inferred from the claim text.