Mobile caster is newest HERL patent

On July 23, 2013, the United States Patent Office awarded Patent No. 8,490,242 to HERL-affiliated inventors Rory A. Cooper, PhD; Andrew M. Kwarciak, MS; Mark A. McCartney; and Jonathan L. Pearlman, PhD for a mobile caster design. 

An object of the caster and caster system of the present invention is to reduce the risk of upper limb pain and injury to wheelchair users by decreasing the forces required to traverse a side-sloped surface. The present invention further prevents caster drift and wheel flutter, by applying a forward or rearward biasing force on the caster wheel, thus lowering the forces required by the downhill limb to maintain a straight path. Another object of the present invention is to provide a caster biasing mechanism or means that can be retrofitted to an existing caster system of a mobile device such as a wheelchair, cart, shopping cart, or dolly. Additionally, the caster fork and wheel of the present invention rotate to allow a user to steer the wheelchair, cart, shopping cart, dolly or other mobile device, when necessary, and provide users with a greater degree of control while traversing a side-sloped surface.

Specifically, what is provided is an improved caster and caster system comprising a caster mount attachable to a frame of a mobile device, a caster stem attached to the caster mount and a biasing means for biasing the caster in a desired rotational position. In one embodiment, the biasing means involves having one or more notches defined in the caster stem, and at least one spring plunger, having a ball defined on one end. The ball is biased against the caster stem and situates within the one or more notches to prevent caster drift and flutter and to promote tracking. In this embodiment, an optional disengaging pin can be provided, which slideably engages the one or more notches to disengage the ball from a notch or notches and allow for the free rotation of the caster.

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