Non-contact double-block speed controller

摘要

In cumulative wire-drawing machines comprising a plurality of dies for successively reducing a diameter of a wire and blocks downstream of each one of the dies for pulling the wire through the dies, the speed of the motor driving the blocks can be automatically controlled by a wire accumulation detection device that detects changes in the amount of wire accumulated on the double-block. Specifically in the context of a double-block type machine, the blocks each comprise a lower segment being driven by the motor to pull the wire through the die, an upper segment for providing the wire to a downstream double-block through a downstream die, and a sheave carried on a ring for transferring the wire from the lower segment to the upper segment. The wire accumulation detection device in this case comprises a cam on the ring and a proximity detection device mounted to the housing of the wire-drawing machine that detects the rotation of the ring by detecting a distance to a surface of the cam. This proximity detection device can be an ultrasonic transducer which emits an ultrasonic pulse towards the cam and then detects returning echo.