Abstract: A tibial component of a prosthetic knee implant comprises an implant tray, medial and lateral articular pads, first and second pivot bearings, and first and second cushion members. The implant tray includes medial and lateral sockets. The medial articular pad is supported within the medial socket by the first pivot bearing which engages the socket's bottom surface and the first cushion member which is sandwiched between the first pivot bearing and the medial articular pad. The lateral articular pad is supported within the lateral socket by the second pivot bearing which engages the socket's bottom surface and the second cushion member which is sandwiched between the second pivot bearing and the lateral articular pad. The pivot bearings pivot, roll, and slide against the socket bottom surfaces whereby the articular pads can pivot and rotate within the sockets. The cushion members absorb forces and impacts experienced by the articular pads.

Abstract: A detection unit (20) for detecting hydrocarbon gases includes a cylindrical housing (20) having a pair of opposed rectangular slots (56, 58) formed in the wall of the housing near the lower end (52). A support (60) is mounted within the housing (50) adjacent the upper end (54). A pair of baffle plates (62, 64) are mounted within the housing from the walls thereof. A semiconductor hydrocarbon gas detector (61) is mounted to the support (60) and is connected by electrical leads (30) to an analyzer and recorder (28). The detection unit (20) is mounted at the mouth of an oil or gas drilling rig and receives drilling mud into the housing (50) at the rectangular slots (56, 58) such that gases released from the drilling mud are analyzed by the gas detector (61) to determine the hydrocarbon gas content therein.