Cut-out for numerically controlled machine tool - uses template and photoelectric cell if control system fails

摘要

The system is intended to stop the machine and prevent damage to workpieces in the event of failure of the numerical control system. A template (22) made of sheet metal, with one edge having a shape corresponding to the devised final profile of the workpiece (14) is fixed to the machine base. The alignment of the template is parallel to the work piece profile. A photoelectric cell and light source (26) is mounted on a support (24) fixed to the tool carrier (16), and its position on the support can be accurately adjusted. If in the event of control failure, the beam of light crosses the edge of the template, the change of reflected light on the photoelectric cell stops the machine.