Abstract: A linear motor and/or compressor (10; 100; 300; 500; 600) comprises a housing (20; 120; 311; 511) fitted with a number of electromagnets (40, 40′; 140, 140′; 315, 315′, 316; 515a-515c, 635a-635d), a shuttle (50; 150; 350; 550; 650) with a central guide (30, 30′; 130; 356, 356′; 520; 655) for keeping it coaxial with the electromagnets and a suspension mechanism for the shuttle including mechanical spring, gas spring and magnetic spring arrangements. The electromagnets form a number of axially exposed magnetic gaps to interact with axially exposed magnetic gaps formed on the shuttle to cause it reciprocate by push-and-pull forces. A phase difference can be produced between the electromagnets to improve shuttle suspension. The central guide can be made hollow to circulate a coolant to cool the compressor from inside.

Abstract: A compressor (10; 100; 200; 300; 500) with a build-in reciprocating motor, comprises a cylindrical housing (20; 120; 210; 510) with two ends thereof fitted with two opposing electromagnets (30; 130; 230; 530), each has a circular inner pole (36; 136) and a coaxial annular outer pole (34; 134). A free piston (50; 150; 250; 560; 600) is disposed in the housing between the two electromagnets, dividing the interior of the housing into two chambers (I, II). The piston carries permanent magnet (40; 140, 145; 561; 610), providing inner and outer poles (44, 46; 141, 146) which have conical surface portions (43, 49; 141, 146) complementary with the corresponding poles (34, 36; 134, 136) of the electromagnets. Sliding pole pieces (630 and 660) can be used to increase the stroke length and reduce the piston's total weight. Valves (61, 63, 65; 161, 165) are fitted to form one-way flow passage connecting the inlet and the outlet of the compressor.

Abstract: A knee/thigh pad holder assembly has adapter hardware for mounting adjustably to a wide variety of ambulatory aids such as walkers, canes, and crutches. The adapter hardware in one embodiment includes a bracket bolted to a knee/thigh pad holder with a holding rod clamped between the bracket and the knee/thigh pad holder. Adjustable clamps with clamping screws are employed to mount the knee/thigh pad holder via the holding rod across two parallel frame members of a walker. In another embodiment, a shorter tube is used in place of the holding rod, and rod clamps are pivotally attached to the short tube, such that the assembly may be adjustably mounted to a single upright member, providing thereby adjustable mounting to such as canes and crutches.

Abstract: An optical display apparatus includes a plurality of optical elements of acrylic material and an additive. Each optical element is shaped into cylindrical body with a first convex end and a second convex end to improve light receiving and transmitting efficiency of the optical element. By activation of a fluorescent lamp, the optical elements can emit ultra-bright color light. A light reflective chamber encloses the fluorescent lamp and the optical elements. Through a panel of the chamber and the optical elements mounted on the panel via apertures of the panel, various desired display patterns may be accomplished. The additive may be fluorescent color dyes or bleaching power. The optical display apparatus further includes a convex lens, a color disc and a motor. The motor drives the color disc to rotate so that light rays focus by the convex lens have variable colors.