Electrolytic grinding apparatus

Claim 1

IN APPARATUS OF THE CHARACTER DESCRIBED, IN COMBINATION, A FRAME HAVING A ROTATABLE SPINDLE CARRYING A GRINDING WHEEL FOR ROTATION THEREBY, SAID GRINDING WHEEL PRESENTING AN OPERATIVE SURFACE THAT COMPRISES THE ALIGNED CONDUCTIVE FACES OF A PLURALITY OF CONDUCTIVE RINGS WHICH ARE RELATIVELY CLOSELY SPACED TO EACH OTHER AND ARE INSULATED FROM EACH OTHER, A WORK-PIECE HOLDER, MEANS ASSOCCIATED WITH SAID FRAME FOR MOUNTING SAID HOLDER TO HOLD A WORK-PIECE IN OPERATIVE RELATION TO SAID OPERATIVE SURFACE OF THE GRINDING WHEEL FOR COACTION WITH SAID ALIGNED FACES OF SAID CONDUCTIVE RINGS, MEANS FOR SUPPLYING LIQUID ELECTROLYTE TO AND BETWEEN THE WORK-PIECE AND SAID ALIGNED CONDUCTIVE FACES OF SAID RINGS, A PLURALITY OF SLIP RINGS, ONE FOR EACH OF SAID CONDUCTIVE RINGS AND IN RESPECTIVE ELECTRICAL CONNECTION THEREWITH, WITH MEANS INSULATINGLY SUPPORTING SAID SLIP RINGS COAXIALLY OF SAID SPINDLE FOR ROTATION THEREWITH, UNIDIRECTIONAL CURRENT-SUPPLY MEANS WITH A PLURALITY OF CONTROL AND SUPPLY CIRCUITS, ONE FOR EACH OF SAID CONDUCTIVE RINGS, ALL OF SAID CIRCUITS HAVING THE POSITIVE SIDES THEREOF ELECTRICALLY CONNECTED TO SAID WORK-PIECE HOLDER WHEREBY THE LATTER AND THE WORK-PIECE ARE ELECTRICALLY COMMON TO SAID CIRCUITS AND HAVING THEIR NEGATIVE SIDES IN ELECTRICAL CONNECTION RESPECTIVELY WITH SAID PLURALITY OF SLIP RINGS WHEREBY UNIDIRECTIONAL CURRENT, FOR ELECTROLYTIC DECOMPOSITION OF THE FACE OF THE WORK-PIECE PRESENTED TO SAID CONDUCTIVE RING FACE OF THE FLOW FROM THE WORK-PIECE TO EACH OF SAID CONDUCTIVE RINGS, AND CONTROL MEANS ASSOCIATED WITH EACH OF SAID CIRCUITS FOR LIMITING MAXIMUM CURRENT FLOW IN EACH OF SAID CIRCUITS TO A VALUE NOT GREATER THAN THE CRITICAL ARCING CURRENT BETWEEN THE WORK-PIECE AND THE RING FACE.