Wheelchair pushrim
OwnerChristopher J. Willems, Mark Baldwin +2inventors
InventorsChristopher J. Willems, Mark Baldwin, Michael L. Boninger, Rory A. Cooper
Life of this patent
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Abstract
A pushrim with increased surface area and an insert between the wheel and the pushrim. In the preferred embodiment, the cross-section of the pushrim is an elongated circle and the insert is a concave trough made of an elastic material which compressibly fits between the wheel and the rim for convenient installation. Improved pushing is provided by texturing the surface of the insert to provide increased friction. Improved braking is provided by providing a smoother and wider surface on the pushrim.
Claims25
A wheelchair pushrim system comprising:
- a) a pushrim;
- b) a wheel connected to the pushrim;
- and
- c) an insert compressibly fit between the pushrim and the wheel.
A wheelchair pushrim system comprising:
- a) a pushrim having a non-circular cross-section;
- b) a wheel;
- c) a connector connecting the pushrim to the wheel;
- and
- d) an insert fit between the pushrim and the wheel.
A wheelchair pushrim system comprising:
- a) a pushrim;
- b) a wheel connected to the pushrim, wherein the pushrim has:
- i. an elongated circular cross-section;
- and
- ii. a support rib;
- c) an insert compressibly fit between the pushrim and the wheel, wherein the insert:
- i. is made of a substantially elastic material;
- ii. is a concave trough;
- and
- iii. has a gripping texture.
A metal pushrim comprising:
- a) a substantially hollow tube of metal bent into a substantially circular shape, the cross-section of the tube comprising:
- (i) a first round end having a first wall thickness;
- (ii) a second round end having a second wall thickness;
- and
- (iii) a substantially flat first side and a substantially flat second side connecting the first round end to the second round end.
A method of making a hollow metal pushrim, having a non-circular cross-section of substantially uniform thickness, comprising the steps of:
- a) extruding a substantially hollow tube of metal in which its cross-section has:
- (i) a first round end having a first wall thickness;
- (ii) a second round end having a second wall thickness, where the second wall thickness is greater than the first wall thickness;
- and
- (iii) a first side and a second side connecting the first round end to the second round end;
- and
- b) bending the tube into a circular shape to form a pushrim, where the first round end is the inside diameter of the pushrim.
Dependencies are inferred from the claim text.