Abstract: An apparatus for positioning a workpiece guiding fence relative to a rotary cutter projecting through the top surface of a work table, comprising a plurality of major components, primarily formed by aluminum extrusions, including a base element securable to the work table surface and having upstanding guiding ribs, an elongated hollow carriage slidably mounted on said ribs and defining a partially cylindrical elongated recess mounting an elongated lead screw. A fence is secured to one end of the carriage. A threaded segment is mounted on a force transmitting element which is moved laterally to engage the threaded segment with the lead screw by a pivoted camming lever having three positions. In the first position, the threaded segment is disengaged from the lead screw, permitting unrestricted longitudinal movement of the carriage relative to the base.

Abstract: Method and apparatus for the fixturing and positioning of objects such as workpieces or lenses in a repeatably presettable position relative to, for example, a cutting tool or other optical components includes a fixed base (40), a carriage (20) and a lead screw (30) rotatable with respect to the fixed base. The carriage (20) translates relative to the base and moves objects attached to it. The exact position of the carriage is indexed by first pressing a button (80A) to release an inside threaded concave cylindrical clamping piece (64) between the carriage and the lead screw and manually moving the carriage (20) to a desired location dictated by a scale (42A, 42B) on the fixed base (40) to relocate to a course number of thread pitch spacings.