Numerical control apparatus for a shear

Abstract

Abstract A numerical control for a shear, making it possible to perform accurately, and without cumulative error, a sequence of cuts on a work piece. Sequence data is entered into an electronic circuit which generates a series of order pulses representative of the data input, and transmits these pulses to a totalizer and to a comparator and to the drive for the gauge bar. Feed back data from the gauge bar, in terms of a series of pulses representative of actual movement of the gauge bar is sent back to the totalizer and to the comparator. Theoretically, when the number of feed back pulses equals the number of order pulses, the gauge bar drive stops. The excess or deficiency in pulses fed back to the comparator with respect to the number of order pulses, is imposed on said order pulses for the succeeding order, to decrease it if the preceding order was overshot, or reduce it if the previous order was undershot, thereby preventing accumulation of errors.

Inventors

• 👤 John J Erhart

Bibliographic Details