Patent ID: 7090241

Claim:
An adjustable seating height wheelchair, comprising: a wheelchair frame providing structural support to the wheelchair; a plurality of wheels, attached to the frame, allowing the wheelchair to roll; a seating surface, providing a seat to a user of the wheelchair; and an adjustable seating height mechanism, mechanically moving the seating surface relative to the wheelchair frame between at least two height levels, the adjustable seating height mechanism including: a pneumatic device extendable and retractable under pneumatic pressure, the pneumatic device coupled to the wheelchair frame and the adjustable seating height mechanism such that when extended, the pneumatic device raises the adjustable seating height mechanism relative to the wheelchair frame to one of the at least two height levels, and when retracted, lowers the adjustable seating height mechanism relative to the wheelchair frame to another of the at least two seating height levels, such that the plurality of wheels all remain in contact with the ground when the adjustable seating height mechanism is extended and retracted; a pneumatic storage tank, coupled to the pneumatic device, storing a gaseous fluid under pressure and providing pressurized gaseous fluid to the pneumatic device to extend the pneumatic device, and a control valve, coupled to the pneumatic storage tank and the pneumatic device, controlling the flow of the gaseous fluid under pressure to and from the pneumatic device such that when actuated, the pneumatic device may be controllably extended and retracted.