Motor controls for electro-magnetic base tool

Claim 1

IN A MACHINE TOOL HAVING A MAGNETIC BASE, A MAGNETIC COIL FOR SAID BASE, A HOLLOW HOUSING HAVING HORIZONTAL AND VERTICAL PORTIONS SUPPORTED ON SAID BASE, A MOVABLE SLIDE ON THE VERTICAL PORTION OF SAID HOUSING, A MOTOR FOR SUPPORTING A TOOL ON SAID SLIDE, SAID HORIZONTAL PORTION HAVING AN ELONGATED APERTURE THROUGH A WALL THEREOF, A REMOVABLE PANEL FOR ENCLOSING SAID APERTURE, A DOUBLE POLE DOUBLE THROW SWITCH ON SAID PANEL, RECTIFYING DIODE UNIT SUPPORTED BY SAID PANEL AND CONNECTIBLE TO A SOURCE OF AC CURRENT AND IN CIRCUIT WITH SAID SWITCH AND SAID MAGNETIC COIL FOR APPLYING THE DC CURRENT FOR MAGNETIZING AND DEMAGNETIZING THE COIL WHEN THE SWITCH IS IN THE ONE OR THE OTHER POSITION, A RELAY SUPPORTED BY SAID PANEL HAVING ITS COIL IN SERIES WITH THE MAGNETIZABLE COIL AND ITS CONTACTS IN THE MOTOR CIRCUIT WHICH CAN BE OPERATED ONLY WHEN THE MAGNETIZABLE COIL IS ENERGIZED, A DOUBLE THROW DOUBLE POLE SWITCH ON SAID PANEL IN THE CIRCUIT FROM SAID RELAY CONTACTS FOR REVERSING THE DRIVE OF THE MOTOR, A RESISTOR IN SERIES WITH MAGNETIZABLE COIL, A SINGLE POLE SINGLE THROW SWITCH ON SAID PANEL FOR SHUNTING SAID RESISTOR TO PERMIT THE COIL TO BE FULLY MAGNETIZED, A POTENTIOMETER ON SAID PANEL, AND A POWER UNIT IN THE CIRCUIT FROM THE RELAY CONTACTS CONTROLLED BY SAID POTENTIOMETER FOR REGULATING THE SPEED OF OPERATION OF THE MOTOR.