Cam operated hydraulic knee joint for an artificial leg

• US 3,417,409 A
• Filed: 09/27/1966
• Issued: 12/24/1968
• Est. Priority Date: 09/28/1965
• Status: Expired due to Term

• Current Assignee: Jan Prahl
• Original Assignee: Jan Prahl
• Inventors: Prahl, Jan
• Application Number:
  US04/582,304
• Time in Patent Office: 819 Days
• US Class Current: 623/26
• CPC Class Codes: A61F 2/64 Knee joints
• CPC Class Codes: A61F 2/68 Operating or control means
• CPC Class Codes: A61F 2/74 fluid , i.e. hydraulic or pneumatic
• CPC Class Codes: A61F 2/748 Valve systems
• CPC Class Codes: A61F 2002/3037 Translation along the common longitudinal axis, e.g. piston
• CPC Class Codes: A61F 2002/30492 using a locking pin
• CPC Class Codes: A61F 2002/30507 using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2220/0025 Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0033 made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit

Claims

1. A KNEE JOINT FOR AN ARTIFICIAL LEG, HAVING AN ELONGATED LOWER PORTION COMPRISING, IN COMBINATION:

(A) A CYLINDER MEMBER DEFINING A CAVITY AND AN EXPANSION CHAMBER THEREIN, AND BEING FORMED WITH CONDUIT MEANS;

(B) A SHAFT MEMBER ROTATABLE IN SAID CYLINDER MEMBER ABOUT AN AXIS;

(C) FASTENING MEANS FOR SECURING SAID MEMBERS RESPECTIVELY TO THE THIGH PORTION AND THE LOWER PORTION OF AN ARTIFICIAL LEG IN A POSITION IN WHICH SAID AXIS IS TRANSVERSE OF THE DIRECTION OF ELONGATION OF SAID LOWER PORTION;

(D) A PISTON AXIALLY MOVABLE IN SAID CAVITY IN SEALING ENGAGEMENT WITH SAID CYLINDER MEMBER, SAID PISTON MEMBER DIVIDING THE CAVITY INTO A PRESSURE CHAMBER AND A COMPARTMENT, SAID PRESSURE CHAMBER BEING CONNECTED TO SAID EXPANSION CHAMBER BY SAID CONDUIT MEANS;