Apparatus and method for determining wire blank length

Abstract

A method and apparatus for detecting the length of wire blanks in a wire cutting machine is disclosed, the machine including feed apparatus for feeding wire stock into the cutting machine, stop apparatus for engaging one end of the wire stock at a predetermined length in the cutting machine, and cutting apparatus for cutting wire blanks from the wire stock. When the leading end of the wire stock engages the stop apparatus with a predetermined pressure, the blank is at a proper length to be cut. The pressure causes the stop apparatus to expand radially. Strain gauges mounted about the stop apparatus detect the expansion by generating an electrical signal when connected in a bridge circuit. The strain gauges detect an over feed situation when the stop apparatus expands beyond a predetermined point. Similarly, an under feed situation is detected when little or no expansion of the stop apparatus is sensed. The strain gauge signal is utilized by the machine operator or automatic control apparatus to control the feed apparatus whereby wire blanks are cut at the desired length. The stop apparatus includes a cylindrical member having a threaded axial aperture formed therein for receiving a screw having one end for receiving the pressure and the other end slotted for adjusting the blank length.