Fluid pressure control device for an artificial leg

Claim 1

An artificial leg comprising: an upper leg member, a lower leg movable relatively to the upper leg member for flexion of the leg, an integral one-piece cylindrical tube constituting a clylinder, a pair of end parts one of which is swingably connected to the lower leg member, locating means to locate respective ends of the cylinder against the end parts and to hold the end parts in spaced relation, a piston slidable in the cylinder, a piston rod connected to the piston and extended through one of the end parts, the piston rod being connected to the upper leg member for movement therewith, a member adjustably secured in one of the end parts and having means constituting an end face for restricting the axial displacement of the piston in one direction, air conveying tubes extending from one end part to the other for conveying air from side to side of the piston, means for allowing passage of air in both end parts for conveying air from respective sides of the piston through the air conveying tubes, an air flow control means mounted in one end part and extending transversely across said air conveying tubes for allowing air to flow freely from side to side of the piSton through all air conveying tubes except one, said air flow control means having means for allowing air to flow in one direction in one air conveying tube but restricting flow in the opposite direction in the same tube, and valves adjustably mounted in a first end part, each valve being operatively associated with a seating in an end of an air conveying tube for controlling air flow therethrough.