Cutter size correction for machine tool control

Claim 1

A CONTROL SYSTEM FOR POSITIONING A CUTTER RELATIVE TO A WORKPIECE IN EACH OF THREE DIRECTIONS DEFINED BY A COORDINATE SYSTEM HAVING X, Y AND Z AXES COMPRISING: A PROGRAMMED DRIVE FOR EACH SAID AXIS, EACH SAID DRIVE COMPRISING A MOTOR CONNECTED TO MOVE SAID CUTTER RELATIVE TO SAID WORKPIECE, A PROGRAMMER STORING A POSITION SIGNAL INDICATIVE OF A DESIRED POSITION OF THE CENTER OF SAID CUTTER RELATIVE TO A POINT ON SAID WORKPIECE TO BE CUT, A DIRECTOR RESPONSIVE TO SAID STORED POSITION SIGNAL FOR GENERATING A COMMAND SIGNAL, GAGE MEANS FOR GENERATING A GAGE SIGNAL INDICATIVE OF THE ACTUAL POSITION OF SAID CUTTER, AND A COMPARATOR RESPONSIVE TO SAID DIRECTOR AND GAGE FOR TRANSMITTING TO SAID MOTOR A DRIVE SIGNAL IN ACCORDANCE WITH THE DIFFERENCE BETWEEN SAID COMMAND AND GAGE SIGNALS; AND A CUTTER DIAMETER CORRECTOR FOR EACH AXIS, EACH SAID CORRECTOR COMPRISING MEANS IN SAID PROGRAMMER FOR STORING A DIRECTION SIGNAL WITH SAID POSITION SIGNALS AND INDICATIVE OF A DIRECTION COSINE OF A LINE BETWEEN SAID DESIRED POSITION AND SAID POINT, MEANS FOR MULTIPLYING SAID DIRECTION SIGNALS BY A SIGNAL INDICATIVE OF A CHOSEN CUTTER SIZE, A CORRECTION CIRCUIT INTERPOSED BETWEEN THE GAGE AND COMPARATOR OF THE CORRESPONDING AXIS DRIVE, AND MEANS FOR TRANSMITTING SAID MULTIPLIED SIGNALS TO SAID CORRECTION CIRCUIT.