Abstract: A rotation sensor for measuring relative rotation or angular orientation between first and second members utilizing polarized light techniques. The present invention also relates to a method for measuring angular orientation using light polarization techniques.

Abstract: A prosthetic leg has a pivotal knee joint and a hydraulic fluid control unit connected to provide variable forces which dampen flexion and extension of the knee and also bias the leg to its extended position. The unit includes an aluminum housing lined with an axially adjustable sleeve and control bushing defining a cylindrical operating chamber which receives a piston mounted on a tubular piston rod. The housing and operating chamber receive hydraulic fluid or oil which flows during movement of the piston through fluid control ports, channels and adjustable gaps defined by the sleeve and bushing for damping the movement of the rod. The piston rod encloses a preferably sealed gas pressurized flexible bladder which forms an oil accumulator during inward movement of the piston rod into a displacement chamber and also produces variable forces for moving the piston rod outwardly to its extended position.

Abstract: Process of melt extruding through an extrusion die whose surface is coated with one or more metal oxides, M.sub.x O.sub.y, wherein M is a metal selected from the group consisting of Ti, Zr, Cr, Fe, Ni, Pd, Pt, Cu, Ag, Au, Al and Si, and x and y are selected to satisfy the valencies of M, a difficultly-melt-processible polymer containing 0.002-2 parts by weight, based on the weight of the polymer, of at least one melt-processible fluorocarbon polymer processing aid having a fluorine to carbon ratio of at least 1:2 and having metal oxide-reactive sites capable of reacting with or physically associating with the metal oxide of the die surface.

Abstract: Passivated (corrosion resistant) stainless steel surfaces for spinnerets, pack parts, filter media, meter pumps, transfer lines, and the like are achieved by oxidizing the surface in an oxidative atmosphere and subsequently soaking the part in a dilute mineral acid solution.

Abstract: A container for spherical objects such as game marbles comprising a hollow torus shaped housing in which objects are admitted to the hollow of the housing by means of an aperture in the housing which is covered or uncovered by a movable closure member. In a preferred embodiment the container includes a hub having an elastic concave receptacle for a shooter marble and the hub is supported within the torus shape of the housing by a plurality of spokes connected to the housing.