Patent ID: 7153190

Claim:
A method of predicting imminent grinding wheel failure by monitoring the wear of a grinding wheel in use, comprising the steps of: measuring the force exerted by a wheelfeed drive which in use urges the wheel into grinding engagement with a workpiece so as to obtain a signal indicative of the force exerted between the wheel and workpiece normal to the grinding face of the wheel at the point of contact between the wheel and workpiece; generating a warning signal when the value of the signal exceeds a predetermined threshold value indicating imminent grinding wheel failure; wherein the wheelfeed drive includes an electrically powered motor, the torque developed by which is proportional to the normal force between the wheel and workpiece, and which is in turn proportional to the electrical power drawn by the motor during operation, whereby an indication of the force between wheel and workpiece is obtained by measuring the power demand made by the motor on its power supply; comparing the value of the force proportional signal obtained during a grinding process on a workpiece with a corresponding value obtained during the grinding process performed on a preceding similar workpiece; and generating the warning signal if a current grinding force signal value differs from a preceding grinding force signal value by more than a predetermined amount.