Position sensor for numerically controlled machine tool - automatically gives feedback signal for correcting machine movement

摘要

The sensor is described in conjunction with a cutting machine tool, on which a workpiece (3) mounted on a table (4) is cut by a tool (6) under the control of a numerical control unit which drives the cutting tool via a leadscrew and nut arrangement. The sensor is attached to the cutting tool mounting so that when the tool moves forward to commence cutting, the front edge of the workpiece is automatically sensed, and the cutting programme can begin correctly. The sensor in this case consists of a probe (18) attached to a synchro resolver (19) via a rack and pinion arrangement. Mechanical or optical transducers are also possible.