Gordon Eugene Groves

US Patent:

56574991, Aug 19, 1997

Filed:

Jan 11, 1996

Appl. No.:

8/586444

Inventors:

Mark R. Vaughn - Albuquerque NM
Edward J. Constantineau - Albuquerque NM
Gordon E. Groves - Tijeras NM

Assignee:

Sandia Corporation - Albuquerque NM

International Classification:

A47C 2710
A61G 7057

US Classification:

5654

Abstract:

An efficient pump system for transferring air between sets of bladders in a cushion. The pump system utilizes a reversible piston within a cylinder in conjunction with an equalizing valve in the piston which opens when the piston reaches the end of travel in one direction. The weight of a seated user then forces air back across the piston from an inflated bladder to the previously deflated bladder until the pressure is equalized. In this fashion the work done by the pump is cut in half. The inflation and deflation of the different bladders is controlled to vary the pressure on the several pressure points of a seated user. A principal application is for wheel chair use to prevent pressure ulcers.