Abstract: A reversible anti-backlash power transmission for selectively transmitting power in opposite directions without backlash in the gear train. The transmission includes interconnected first and second gear boxes. Each gear box includes a drive shaft having a worm associated with the drive shaft for rotation therewith, a worm gear in meshing engagement with the worm, a driven shaft associated with the worm gear for rotation therewith, and a pinion gear structurally associated with the drive shaft for rotation therewith. A rack gear is in meshing engagement with the pinion gear of each of the first and second gear boxes. An electro-magentic coupler interconnects the drive shafts of the gear boxes. The coupler allows the automatic angular displacement of the drive shafts of the two gear boxes relative to each other to eliminate gear backlash in any of the mating gears.

Abstract: An apparatus for manipulating a tool along a spiral path into a circular or orbital path includes a first shaft and a second shaft in end-to-end relationship. The apparatus includes a slide device interconnecting the adjacent ends of the first and second shafts for allowing the second shaft to move tranversely of and in a generally radial direction away from the first shaft as the first shaft rotates about its own longitudinal axis. The tool to be manipulated is attached to the distal end of the second shaft. As the first shaft rotates about its own longitudinal axis, the second shaft moves radially away from the first shaft so that the second shaft, and tool attached thereto, follow an initial spiral path leading into an orbital path centered on the longitudinal axis of the first shaft.

Abstract: An apparatus for dispending a fluid free of included air bubbles, such as for example, an adhesive bead, includes sensing devices for detecting the presence of an included air bubble in the conduit leading from a source of the fluid to a discharge of a movable fluid dispenser. The sensing devices are connected to a motor which drives an arm on which the fluid dispenser is mounted. A first sensing device slows movement of the dispenser upon sensing an air bubble in the fluid and a second sensing device stops movement of the dispenser upon sensing an air bubble in the fluid. The movement of the dispenser is restarted after a predetermined time period sufficient to allow the air bubble to pass out of the dispenser discharge. The sensing devices advantageously use a light beam, such as infra-red light or laser, to detect the presence of the included air bubble.