HYDRAULICALLY AMPLIFIED VACUUM PUMP FOR PROSTHETIC AND ORTHOTIC DEVICES

摘要

Methods and apparatus are disclosed relating to a mechanical vacuum socket pump used to establish a vacuum in a socket of an artificial limb. In one case, the pump includes a housing within which two pistons coaxially reciprocate. A surface of each of the pistons is linked hydraulically, such that driving one piston causes movement of the other piston through a hydraulic chamber. One piston is also linked to a pneumatic chamber such that movement of that piston draws air from a limb socket or expels air to the atmosphere upon movement of the piston's pneumatic surface. The surface area of the hydraulic surface of this piston is significantly less than the surface area of the pneumatic surface, so a small volumetric displacement of hydraulic fluid may cause a large displacement of air. Thus, the pump efficiently pumps air with minimal compression and extension of the pump as a whole.

主权项

1. A vacuum socket pump apparatus for an artificial limb, the pump apparatus comprising:
a limb socket; a housing having a socket connection portion and a prosthetic limb connection portion, the socket connection portion being adapted to connect to the limb socket, the prosthetic limb connection portion being adapted to connect to a prosthetic limb portion; a first piston configured to reciprocate within the housing; a second piston configured to reciprocate within the first piston upon displacement of the first piston relative to the housing, the second piston having a pneumatic surface; the second piston and the housing forming a pneumatic chamber between an interior surface of the housing and the pneumatic surface, the pneumatic chamber configured to receive air from the socket upon expansion of the pneumatic chamber and to evacuate air from the pump apparatus upon compression of the pneumatic chamber; wherein displacement of the first piston relative to the housing hydraulically produces a greater displacement of the second piston relative to the housing.