Wheelchair
AssigneeAtlantic Richfield Company
InventorDonald F. Wilkes
Life of this patent
Estimating the term…
Abstract
A wheelchair and rolling suspension system are supported by a pair of inclined, nested circular hoops. The hoops may be manually driven by lever arms accessable to the chair occupant. Moreover, the drive system permits the chair to negotiate straight lines, gradual and sharp curves, as well as to rotate about a vertical axis. The wheelchair is a two-wheel system having self-righting characteristics and is collapsible for storage and transportation. A seat assembly is articulatable between a vertically upright position and a fully reclined position. In addition, the wheelchair can function as a rocking chair.
Claims12
In a wheelchair of the type having a seat and a rolling suspension means, the improvement comprising locomotion means for driving the suspension means, the locomotion means including hand operable levers having end portions which orbit in a cambered elliptical path to efficiently utilize human anatomical strengths and weaknesses, the end portions being operable to drive the locomotion means throughout the orbit.
In a wheelchair of the type having a seat and a rolling suspension means with rolling supports, the improvement comprising:
- a crankshaft connected to drive the suspension means;
- a pair of members mounted on the crankshaft, each member carrying a pivot eccentrically to the crankshaft, the pivots lying on a diameter of the crankshaft but on opposite sides thereof;
- a pair of lever arms, one end of each arm connected to a corresponding pivot, the second end of each arm being manually operated;
- and
- a link pivotally connected to each arm between the first and second ends thereof, connected to the suspension means, and operable to cause the second end of each arm to traverse a cambered ellipse as the first end of each arm traverses a circle, whereby the anatomical strengths and weaknesses of the operator are efficiently utilized.
In a wheelchair of the type having a seat and a rolling suspension means with rolling supports, the improvement comprising:
- a crankshaft connected to drive the suspension means;
- a pair of members mounted on the crankshaft, each member carrying a pivot eccentrically to the crankshaft, the pivots lying on a diameter of the crankshaft but on opposite sides thereof;
- a pair of lever arms, one end of each arm connected to a corresponding pivot, the second end of each arm being manually operated;
- a link pivotally connected to each arm between the first and second ends thereof, connected to the suspension means, and operable to cause the second end of each arm to traverse a cambered ellipse as the first end of each arm traverses a circle, whereby the anatomical strengths and weaknesses of the operator are efficiently utilized;
- and
- further including differential gearing connected with the crankshaft and the rolling supports so as to permit different rotational rates for the rolling supports during maneuvers of the wheelchair.
A wheelchair comprising:
- a rolling suspension means including a pair of ring members devoid of spokes and web structure, each ring member being inclined relative to the other ring member and to a supporting surface;
- and
- an articulatable seat means supported by the rolling suspension means and being collapsible in the longitudinal direction of the rolling suspension means.
Dependencies are inferred from the claim text.