Broken tool detector

摘要

This invention relates to the detection of tool ( 50 ) and other items used on machines by use of a detector ( 5 ). An emitter ( 10 ) emits a beam of laser light ( 20 ) and sensor ( 30 ) is used to determine the presence or absence of a tool ( 50 ) when the tool is positioned in the beam. If any light is present at the sensor ( 30 ) within a predetermined time period then the tool must be broken and the output of the detector is latched. Thus if a broken tool is present and contamination obstructs the beam then this is ignored provided some light is sensed.