Abstract: A cup for reconstruction of an acetabulum in a pelvis, and a method for installing the apparatus. The cup is generally ellipsoidal in shape, with a rigid keel extending from the convex surface of the cup at a given angle. An ellipsoidal concave cavity is formed in the pelvis, and a stabilization channel is formed into the pelvis, at an angle which is close to, but slightly less than the angle on the keel. The cup is installed in the concave cavity, and the rigid keel is forced into the stabilization channel.

Abstract: A metallic implantable finger joint has a biocompatible protective coating and includes both a base member and a protraction member. The base member is formed with a recess and has a protrusion projecting from inside the recess. The protraction member has a hemispherical surface which is slidingly engageable with the recess of the base member. Additionally, the protraction member is formed with a groove which engagingly receives the protrusion from the base member. This engagement is such that when the base member is juxtaposed with the protraction member, the interaction between the protrusion and the groove allows for relative movement between the members in flexion-extension, lateral rotation and pure rotation. The finger joint can also include implant barbs which are selectively engageable with the base member and the protraction member.

Abstract: A prosthetic knee joint to articulate and rotate the femur relative to the tibia includes an artificial femoral condyle which is mechanically attachable to the femur, and an artificial tibial plateau which is mechanically attachable to the tibia for articulation with the femoral condyle. The femoral condyle has a convex surface and a pair of cylindrical lobes which coaxially extend from the femoral condyle. On the other hand, the tibial plateau has a concave recess which slidingly receives the convex surface and it has a concave cradle which slidingly receives the pair of cylindrical lobes. For operation of the knee joint the concave recess and the concave cradle are oriented and dimensioned on the plateau to sequentially and respectively receive the convex surface and the pair of cylindrical lobes as the femur is moved in flexion and extension relative to the tibia.

Abstract: A servo amplification system is created particularly for heavy construction equipment, but has a general utility that is much broader. The system utilizes a hydraulic analog system with a separate subsystem for each dimension of motion. The operator moves the operative element, such as the backhoe bucket, of the analog replica which ordinarily would be situated in the cab of the backhoe or other piece of equipment. A small hydraulic cylinder operative in response to movement at each articulated connection of the backhoe operates a pilot valve which controls a pilot piston mechanically linked to the drive valve of the drive cylinder of the corresponding articulation in the actual backhoe. A feedback system comprising a mechanical link from the actual drive piston to a feedback cylinder and piston delivers hydraulic fluid back to the inlets of the pilot valve in such a way as to cancel the pilot orders from the initial control cylinder.

Abstract: A servo amplification system is created particularly for heavy construction equipment, but has a general utility that is much broader. The system utilizes a hydraulic analog system with a separate subsystem for each dimension of motion. The operator moves the operative element, such as the backhoe bucket, of the analog replica which ordinarily would be situated in the cab of the backhoe or other piece of equipment. A small hydraulic cylinder operative in response to movement at each articulated connection of the backhoe operates a pilot valve which controls a pilot piston mechanically linked to the drive valve of the drive cylinder of the corresponding articulation in the actual backhoe. A feedback system comprising a mechanical link from the actual drive piston to a feedback cylinder and piston delivers hydraulic fluid back to the inlets of the pilot valve in such a way as to cancel the pilot orders from the initial control cylinder.

Abstract: A torque multiplier assembly that is portable, compact, and may be easily and conveniently disposed adjacent a nut, bolt or similar threaded elements to removably engage the same. The torque multiplier assembly when so engaged is adapted to exert a first relatively high maximum torque of predetermined value on the nut, bolts or similar elements to initially rotate the same from binding threaded engagement or perform the final tightening of the nut bolt or rotatable element. The torque multiplier assembly is manually actuated by the use of an elongate torque wrench of a type that is commercially available and may be adjusted to supply any one of a number of maximum torque. The desired maximum torque supplied by the elongate torque wrench is relatively low, normally not over fifty foot pounds, and is visually indicated on a calibrated scale that forms a part of the torque wrench.