Wire drawing control apparatus

Abstract

In a magnet wire fabrication process in which the drawing of wire is 'in-line' with the enameling process, it is often a requirement that the drawing machines be supplied with electrical power from the utility grid rather than relying on an 'in-house,' closely regulated supply of electrical power. In such cases, during voltage dips on the grid, the drawing machine motors will slow down while the wires continue to be pulled from the drawing machine at the same speed as before. A wire accumulator is interposed between the drawing machines and the enameling oven to prevent breakage of wire by providing an accumulation of wire to be used in the event of such a voltage dip. The present invention discloses an apparatus for controlling the various channels of the accumulator so as to provide roughly equivalent amounts of wire in each channel so that the integrity of all channels during a power dip is assured. A central operator control station for effecting the desired control is disclosed. It comprises, among other things, a keyboard and a display for entering a desired wire gauge size to be drawn, and a signal processor for controlling the accumulator channels according to the commanded gauge size. A plurality of controllers for each channel are responsive to a speed command signal from a pulling capstan at the enameling end of the process. This signal is modified by a feedback signal derived from the accumulator channels so as to indicate the actual running speed of the various drawing machine motors and at the same time control the amount of wire accumulated in the various channels.