Abstract: An ultrasonic positioning system having multiple degrees of freedom of movement includes an array of piezoelectric ceramic elements grouped in pairs of adjacent ceramic elements of opposite deformation responses aligned in a first direction and also pairs aligned in a second direction, an elastic body bonded to the ceramic elements, and a moving body movably supported on the elastic body for movement in at least the two directions. The pairs of ceramic elements are activated with offset pairs of ceramic elements by electrical signals offset in phase to generate a traveling wave for driving the moving body. In a preferred embodiment, the ceramic elements have a length to width ratio of 2:1 with their lengths aligned in the X direction and widths aligned in the Y direction. When excitation signals having a frequency corresponding to either their length or width are applied, the ceramic elements can vibrate in two modes to drive the moving body in the X or Y direction.

Abstract: A multi-channel band-gear system for a rotary joint has a ring gear assembly with a conducting ring band in electrical contact with corresponding conducting bands of a set of intermediary planetary gears, which in turn are in electrical contact with a conducting sun band of a sun gear assembly. The ring band is formed with a plurality of conducting segments which are electrically insulated from each other and positioned angularly in a circumferential direction of the ring gear, such that separate electrical power/signal channels are formed across the rotary joint. In a preferred embodiment having continuously connected channels, the ring band has four conducting segments at 90.degree. intervals, the sun band has two conducting segments at 180.degree. intervals, and three planetary bands are in rolling electrical contact at 120.degree. intervals between the ring band segments and the sun band segments, forming two continuously connected channels in a single layer of the band-gear system.

Abstract: A threaded fastener has a standard part with a standard thread form characterized by thread walls with a standard included angle, and a modified part complementary to the standard part having a modified thread form characterized by thread walls which are symmetrically inclined with a modified included angle that is different from the standard included angle of the standard part's thread walls, such that the threads of one part make pre-loaded edge contact with the thread walls of the other part. The thread form of the modified part can have an included angle that is greater, less, or compound as compared to the included angle of the standard part. The standard part may be a bolt and the modified part a nut, or vice versa.

Abstract: A clutch or brake device has locking sprags engageable between its inner and outer races which have a three-dimensional wedge shape with respect to the rotational (Z) axis. The 3D locking sprags have contact surfaces shaped to make rectangular area contact with the corresponding surfaces of the inner and outer races for reduction and improved distribution of contact stresses. The 3D sprags are also shaped with a constant-angle contact surface in cross-section in a plane normal to the Z-axis for self-compensation with wear and maintenance of effective locking angles under loads.

Abstract: A flexible band-gear system has an ring gear assembly with bands in electrical contact with and a ring gear in mechanical engagement with corresponding bands and gears of planet gear assemblies which are in turn in electrical contact and geared engagement with a sun gear assembly mounted to a rotating shaft. Electrical power and/or an electrical signal can thus be conducted across a rotating joint which also transfers mechanical power. The flexible band-gear system can also be used in linear applications to transfer electrical power/signal via rolling contact with a linear band. The geared aspect of the system simplifies axial alignment and maintains the relative positions (within the ring annulus) of the planet gears. Electrical power and signal capacity can be varied with the number of planet gears in the system. Multiple channels are added using segmented contact bands and/or multiple contact band layers.