Stanley C Schoonover

US Patent:

39341852, Jan 20, 1976

Filed:

May 30, 1974

Appl. No.:

5/474553

Inventors:

Stanley C. Schoonover - Waynesboro PA

Assignee:

Landis Tool Company - Waynesboro PA

International Classification:

G05B 2300
G05B 1900

US Classification:

318565

Abstract:

A machine tool control system moves a grinding wheel from a retracted position to a forward position by causing hydraulic fluid to be applied under pressure to a hydraulic cylinder to effect rapid forward movement of the grinding wheel to a forward position whereupon further movement of the grinding wheel to a final position is effected by supplying a predetermined number of pulses to a stepping motor for driving the feed screw in accordance with a predetermined sequence of grinding movements. Upon completion of the grinding operation, the grinding wheel is reset to the initial retracted position by applying hydraulic fluid to another portion of a cylinder to rapidly move the grinding wheel from the forward position to the retracted position while at the same time applying the same predetermined number of pulses to the stepping motor so as to reversely rotate the feed screw to return the grinding wheel to the initial position. To confirm an accurate resetting of the grinding wheel within an acceptable margin of error, a pulse generator operated by the actual movement of the feed screw produces verification pulses which are received by a reset confirmation circuit which at the conclusion of the resetting operation monitors a number of pulses corresponding to the acceptable margin of error to determine whether the grinding wheel has been reset to the initial position. If the reset confirmation circuit receives an insufficient number of verification pulses, indicating an underreset condition, or receives too many pulses within a period of time corresponding to the acceptable margin of error, indicating an overreset condition, then further operation of the machine tool will be prevented.

US Patent:

39342000, Jan 20, 1976

Filed:

Jan 31, 1975

Appl. No.:

5/545993

Inventors:

Stanley C. Schoonover - Waynesboro PA
Michael D. McIntosh - South Mountain PA

Assignee:

Landis Tool Company - Waynesboro PA

International Classification:

G01P 346

US Classification:

324163

Abstract:

A D. C. tachometer circuit comprising a non-linear D. C. tachometer which produces an output voltage having an A. C. ripple, a first current path from the D. C. tachometer including means for removing the D. C. component of the output voltage of the tachometer, means for inverting and isolating the A. C. voltage ripple, and means for eliminating drift and the D. C. level of the inverted and isolated A. C. voltage-ripple, means for mixing the original output voltage of the D. C. tachometer including the A. C. ripple and the inverted and isolated A. C. voltage ripple to establish a non-linear ripple-free output voltage, and means for linearizing the non-linear ripple-free output voltage.