Abstract: A trailer dolly includes an internal combustion engine, a transmission providing both forward and reverse drives, and a centralized lifting handle. The internal combustion engine provides much better power and much less weight than electric counterparts. The forward/reverse transmission includes a sliding shaft which engages a select one of two bevel gears with a larger bevel gear to select forward or reverse drive. The sliding shaft slides along with an elongated clutch cylinder of a centrifugal clutch. An alternative transmission uses sprockets and chains to obviate a case to enclose lubricant. Counter-rotating sprockets alternatively engage a dog-tooth gear to select either forward or reverse drive. The lifting handle mounted generally at the center of gravity (with the trailer dolly in a substantially horizontal position) makes single-handed lifting and carrying of the trailer dolly quite easy.

Abstract: A precision robot apparatus (10) is disclosed which has an arm supporting cylinder (16) capable of being moved vertically by means of a lead screw (24) which rotates within a lead screw nut (38) attached to the arm supporting cylinder (16). A linear guide rod (44) is positioned parallel to the arm supporting cylinder (16) with an anti-rotation plate (42) therebetween. An arm drive belt (74) transfers rotational power from the linear guide rod (44) to the arm supporting cylinder (16). Rotational motion of the arm supporting cylinder (16) relative to a fixed arm pulley (92) is employed to power an arm portion (14).

Abstract: An arm structure includes either two or three links pivotally connected to one another with a hand or end effector at the distal end of the distal link. Straight line movement of the pivoting mounting place of the end effector is provided from a rotating drive wheel coaxial with the pivoting of the proximal end of the proximal link. A drive wheel coaxially with the pivot of the proximal end of the proximal link causes the first and second links to pivot about their pivot axis. This pivoting causes the first link to pivot about its proximal end and causes the end effector to pivot in the two link version and causes the second and third links to pivot about their pivot axis in the three link version. A housing can be present intermediate the ends of the first link to provide a gearing adjustment. Generally, .theta. and Z motors also are present. The arm structure is useful for moving wafers, hard computer discs, and the like for processing, loading, unloading, etc.