METHODS OF AND APPARATUS FOR DETECTING OPENINGS IN CABLE JACKETS

摘要

Boggs, L. M. 4-5 METHODS OF AND APPARATUS FOR DETECTING OPENINGS IN CABLE JACKETS An opening in a jacket of a cable is detected as the jacketed cable is moved from an extruder through a probe which is positioned in a cooling trough and which comprises first and second aligned, spaced sensors with each of the sensors being connected to an arm of a bridge transformer. Electrical circuitry is designed to cause an unbalance voltage in a secondary of the transformer in response to conductance unbalance as the opening in the jacket is advanced through the first sensor and to cause an unbalance voltage of opposite polarity in the secondary in response to conductance unbalance as the opening in the jacket is advanced through the second sensor. Logic circuitry tests the unbalance voltages for threshold and peak values to discern jacket holes despite the presence of extraneous signals such as those which are caused by noise. - i