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US 5,762,155 AGranted
Wheelchair frame and castor assembly
AssigneeRichard van Seenus Nederland B.V.
InventorPetrus Johannes Scheulderman
Life of this patent
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Abstract
A wheelchair frame comprises a base frame part (1, 2) with a plurality of wheels (3, 33), including two front wheels (3), wherein each of said front wheels can be driven by an electromotor (4). The base frame part carries at the back side a castor assembly (13) located in the center and comprising a swivel axle (14) with a neutral straight on position, wherein a device 22 is are provided for exerting a rotation force on the swivel axle in the direction of the straight on position at rotation of the swivel axle out of the straight on position.
Claims15
A wheelchair frame comprising:
- a base frame part having a front portion and a rear portion;
- a fork assembly mounted to the rear portion, the fork assembly having two legs movable between a neutral position and an urging position;
- a pair of front wheels rotatably coupled to the front portion of the base frame part defining a longitudinal center plane of the base frame part therebetween;
- an electric motor coupled to each front wheel;
- and
- a castor assembly rotatably coupled to the rear portion of the base frame part by a swivel axle at the center plane, the castor assembly having a neutral straight on position, the castor assembly further coupled to the fork assembly and having an eccentric member which is substantially fittingly positioned between the legs of the fork assembly when the castor assembly is in the neutral straight on position;
- and
- wherein rotation of the castor assembly from the neutral straight on position causes the eccentric member to move at least one of the legs from the neutral position in a direction away from the center plane to the urging position such that a restoring force is imparted on the castor assembly to rotate the castor assembly back to the neutral straight on position.
5 more elements
A castor assembly comprising:
- a swivel axle;
- a support plate rotatably mounted to the swivel axle;
- a bearing pin secured to the support plate remote from the swivel axle;
- a fork assembly disposed on the support plate having a pair of fork legs each leg having a half-round seat;
- a spring urging the half-round seats of the fork legs upon the bearing pin;
- and
- an eccentric member provided on the swivel axle and substantially fittingly positioned between the fork legs in a neutral straight on position wherein rotation of the swivel axle relative to the support plate moves at least one of the legs against the spring to create a restoring force to return the eccentric member to the neutral straight on position.
4 more elements
A wheelchair frame comprising:
- a base frame part having a front portion and a rear portion;
- a transverse axle coupled to the front portion of the base frame part;
- a fork assembly mounted to the rear portion, the fork assembly having two legs movable between a neutral position and an urging position;
- a pair of front wheels spring mounted and rotatably coupled to the transverse axle defining a longitudinal center plane of the base frame part therebetween such that the pair of front wheels rotates about an axis which lies ahead of the transverse axle in a forward direction;
- an electric motor coupled to each front wheel;
- and
- a castor assembly rotatably coupled to the rear portion of the base frame part at the center plane and having a neutral straight on position, the castor assembly further coupled to the fork assembly wherein rotation of the castor assembly from the neutral straight on position moves at least one of the legs from the neutral position in a direction away from the center plane to the urging position such that a restoring force is imparted on the castor assembly to rotate the castor assembly back to the neutral straight on position.
4 more elements
The wheelchair frame according to clam 13, and further comprising:
- first and second bushings disposed in the front portion of the base frame part, each bushing rotatably coupling one of the support arms on the transverse axle;
- a first pulling rod having first and second ends, the first end of the first pulling rod coupled to the first lever at the second end of the first lever;
- a second pulling rod having first and second ends, the first end of the second pulling rod coupled to the second lever at the second end of the second lever;
- a first coupling arm coupled to the first bushing and the second end of the first pulling rod;
- a second coupling arm coupled to the second pushing and the second end of the second pulling rod;
- and
- wherein pivotal movement of the front wheels about the transverse axle causes a deflection of the common spring.
4 more elements
Dependencies are inferred from the claim text.