Abstract: A device for releaseably holding a workpiece includes a resilient collet which is attached to a base by an elastomeric member. Typically, the collet is an annular ring. Several fingers for holding the workpiece extend from the collet. The fingers are pivoted by actuating a member which elastically deforms the collet and causes the fingers to pivot from a position for engaging the workpiece to a position for releasing the workpiece and vice-versa. In one application, the base is a platen for supporting a wafer in a semiconductor processing system, and a plurality of the holding devices are arranged around the periphery of a rotating disk. A counterweight ring is attached to the collet to counterbalance the moment generated by the centrifugal force of the wafer pressing against the fingers as the disk is rotated.

Abstract: Continuous-curvature lobed cams, such as are variously used after the manner of gearing in orbital-drive mechanical transmissions, hydraulic motors and the like, are formed with the precise and continuous distinctive contouring which is essential to their successful operation by way of a simple and inexpensive cutting tool rotated about a fixed axis in a conventional machine while the cam blank with which it is in a material-removing engagement is both rotated relatively slowly in one angular direction and orbited relatively rapidly and synchronously along a circular path in the opposite angular direction. Synchronism between the slow rotary and rapid orbital motions is achieved in a machine-mounted fixture through geared drive of two rotary tables from a common motive source on the same movable platen which mounts the two rotary tables.