Control and operating system for electrolytic hole sinking

Claim 1

IN AN ELECTROLYTIC MACHINING APPARATUS HAVING A TOOL ELECTRODE, MEANS FOR POSITIONING A WORKPIECE, ELECTRICALLY ENERGIZED MEANS FOR RELATIVELY MOVING THE WORKPIECE POSITIONING MEANS AND THE ELECTRODE, MEANS FOR SUPPLYING ELECTROLYTE TO THE SORK GAP BETWEEN THE ELECTRODE AND THE WORKPIECE, AN AN ELECTRICAL SYSTEM OF HIGH CURRENT CAPACITY CONNECTED TO SUPPLY A LOW VOLTAGE DIRECT CURRENT BETWEEN THE WORKPIECE AND THE ELECTRODE IN A SENSE TO MAKE THE ELECTRODE CATHODE, THE COMBINATION COMPRISING (A) MANUALLY OPERABLE SWITCH MEANS CONNECTED TO INITIATE OPERATION OF THE MOVING MEANS AND THE ELECTRICAL SYSTEM, (B) AN ELECTRON DISCHARGE DEVICE AND CIRCUIT THEREFOR, (C) CIRCUIT MEANS CONNECTED FOR ESTABLISHING POTENTIALS UPON SAID DISCHARGE DEVICE TO RENDER SAID DEVICE NORMALLY NONCONDUCTING, (D) MEANS FOR CHANGING THE POTENTIALS UPON SAID DISCHARGE DEVICE TO RENDER AND DEVICE CONDUCTING, (I) SAID POTENTIAL CHANGING MEANS HAVING A PAIR OF IMPUT TERMINALS CONNECTED TO THE WORKPIECE AND ELECTRODE, RESPECTIVELY, AND (II) BEING ACTUATED BY A RAPID CHANGE IN THE POTENTIAL DIFFERENCE BETWEEN SAID TERMINALS CAUSED BY A SPARK PASSED BETWEEN THE WORKPIECE AND THE ELECTRODE, (E) NORMALLY CLOSED SECOND SWITCH MEANS CONNECTED IN SERIES WITH SAID MANUALLY OPERABLE SWITCH MEANS AND WHICH WHEN OPENED DEENERGIZES THE MOVING MEANS AND THE ELECTRICAL SYSTEM, (F) RELAY MEANS CONNECTED TO RECEIVE CURRENT FROM SAID ELECTRON DISCHARGE DEVICE AND TO BE ENERGIZED THEREBY, (I) SAID RELAY MEANS WHEN ENERGIZED BEING CONNECTED TO OPEN SAID NORMALLY CLOSED SECOND SWITCH MEANS AND TO OPEN SAID CIRCUIT WHICH INCLUDES SAID ELECTRON DISCHARGE DEVICE, (G) AND A TIME DELAY RELAY CONNECTED IN THE OPERATED BY THE ENERGIZATION OF SAID RELAY MEANS AND BEING CONNECTED TO PREVENT DLSOING SAID DISCHARGE DEVICE CIRCUIT FOR A PREDETERMINED TIME PERIOD.