Stair vehicle
First Claim
1. A device for use in moving a load up or down a stepped path, comprising a structure for receiving the load, at least one support element rotatably mounted on the structure and having rotatably mounted thereon at least three symmetrically disposed wheels whereby, in use, the wheels cooperate with successive steps of the path, and foot means secured to each support element adjacent the corresponding wheel, the foot means being clear of the circumference of the wheel at two regions so that the wheel can roll freely on a plane when the support element is positioned with the wheel and respectively one or other of the adjacent wheels in contact with the plane, and having engagement portions located forwardly of the said two regions so as, when the support element is rotated forwardly of the said position, to engage the plane to prevent rolling movement.
1 Assignment
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Accused Products
Abstract
The vehicle--e.g. a wheelchair--has groups of wheels (10) mounted on a spider (9) for rotation about a central axis to enable the vehicle to ascend or descend stairs or steps. To reduce the risk of the vehicle rolling off the steps, each wheel has alongside it a foot member (further wheel 13), rigidly secured to the spider, with engagement portions (18) to engage the stair when the spider is tilted and clear portions (14) allowing free rolling when the spider is level. Also, a geared drive arrangement to the spider(s) is provided to give braking or restraint with a mechanical advantage. In a further embodiment the drive motor for rotating the spiders is mounted on a pivoted projecting arm or skid (27, FIG. 6) which transmit the motor or braking torque directly to the stairs to reduce the risk of the vehicle tipping.
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Citations
11 Claims
- 1. A device for use in moving a load up or down a stepped path, comprising a structure for receiving the load, at least one support element rotatably mounted on the structure and having rotatably mounted thereon at least three symmetrically disposed wheels whereby, in use, the wheels cooperate with successive steps of the path, and foot means secured to each support element adjacent the corresponding wheel, the foot means being clear of the circumference of the wheel at two regions so that the wheel can roll freely on a plane when the support element is positioned with the wheel and respectively one or other of the adjacent wheels in contact with the plane, and having engagement portions located forwardly of the said two regions so as, when the support element is rotated forwardly of the said position, to engage the plane to prevent rolling movement.
Specification