Programmable turret-type machine tool

A programmable turret type machine tool, comprising:

• (a) a machine tool base having a turret assembly including a machine tool turret which is rotatably mounted on the base and has a plurality of spaced machine tools,
• (b) the turret assembly including a machine tool turret rotating means which is connected to the turret for rotating it so that the spaced turret machine tools are successively rotated to a work station position,
• (c) a gear train having an input element rotatably connected to the machine tool turret assembly and having an output shaft the rotation of which accurately reflects the amount of machine tool turret rotation,
• (d) a rotor which acts as an element in a sensing circuit and is fixedly mounted on the gear train output shaft being rotatable therewith at a fixed angular correlation with respect to the rotation of the machine tool turret,
• (e) an encoding assembly mounted on the base and which has a plurality of arcuately spaced sensing elements disposed in a plane on a circult line adjacent the path of rotation of the rotor so as to permit successive interaction between the rotor and the spaced sensing elements,
• (f) the encoding assembly producing a different coded output signal for the interaction of the rotor with different sensing elements,
• (g) each spaced sensing element positioned to correspond with a given work station and to provide a lead angle with respect to the actual position of the corresponding turret machine tool to give a brief time interval in which the control elements can function before arrival of the machine tool at the work station,
• (h) program means for controlling machine tool work station selection by providing a series of coded output signals which correlates with the codes produced by the encoding assembly,
• and
• (i) comparator means connected to the program means and to the encoding assembly for receiving the coded signals, and having an output line connected to the turret assembly for producing a turret assembly control signal when the received code from the encoding assembly unit correlates with the coded signal from the program means for a given desired work station.