US 5,772,237 A · Suspension system for powered wheelchair

Abstract

A suspension system for the ground engaging powered and/or caster wheels of a power wheelchair utilizes three links, two of which are universally pivotally connected between the frame of the wheelchair and a wheel mounting transaxle housing or subframe so that the wheels can tilt relative to the frame of the wheelchair in a vertical plane. A third link is connected between the vehicle frame and the wheel mounting structure which can only pivot in a vertical plane, thus restraining the wheels from any lateral displacement relative to the vehicle frame. Fluid cylinders operable between the links and the vehicle frame provide cushioning of the frame and also, by subtraction of fluid from the fluid cylinders, can lower the entire frame of the wheelchair relative to the ground engaging wheels to permit the wheelchair and occupant to drive into the side door opening of a conventional van.

Claims8

Dependent claims

A suspension system for a powered wheelchair having an elongated frame supporting an occupant seat comprising;

a transaxle housing having a pair of power driven wheels mounted on opposite ends of said transaxle housing;
a first linkage means for connecting said transaxle housing in transverse relation to the length of said elongated frame with said transaxle housing being freely tiltable in a vertical plane transverse to said elongated frame;
said first linkage means including universal pivot bearings on said elongated frame and said transaxle housing, whereby said power driven wheels may separately follow the contour of the ground traversed by said power driven wheels;
a fluid pressure cylinder operatively connected between said first linkage means and said frame for vertically positioning said elongated frame relative to said ground engaging power wheels;
and
operator controlled means for supplying and withdrawing fluid from said fluid pressure cylinder.

3 more elements

A suspension system for a powered wheelchair having a rigid, elongated frame with longitudinally spaced, depending first and second vertical frame portions, a laterally disposed transaxle housing, a pair of power driven wheels rotatably mounted on opposite lateral ends of said transaxle housing and caster wheel means mounted on said second vertical frame portion for supporting one end of said elongated frame, comprising, in combination:

a pair of horizontally aligned, laterally spaced, universal pivot mountings on said first vertical frame portion;
a pair of identical mounting links respectively having one end universally pivotally mounted in said pair of universal pivot mountings and the other end universally pivotally secured to said transaxle housing, whereby said power driven wheels can move in a vertical plane;
a pair of laterally spaced, horizontally aligned, single axis pivot mountings on said first vertical frame portion vertically spaced relative to said pair of universal pivot mountings and defining a common horizontal axis;
a stabilizing link having a generally triangular configuration defining a wide base portion and a vertex portion;
means on opposite ends of said base portion of said stabilizing link for respectively engaging said pair of single axis pivot mountings to permit pivotal movement of said stabilizing link only in a vertical plane;
and
means for universally pivotally connecting said vertex portion of said stabilizing link to the lateral center of said transaxle housing;
thereby preventing lateral movement of said power wheels relative to said elongated frame without restricting independent vertical movements of said power driven wheels to conform to the ground contour.

5 more elements

Dependencies are inferred from the claim text.

Suspension system for powered wheelchair

Life of this patent

Suspension system for powered wheelchair

Life of this patent

Abstract

Claims8