Electrode for electrolytic cavity sinking

Claim 1

IN AN APPARATUS FOR ELECTROLYTICALLY MACHINING A CAVITY IN AN ELECTRICALLY CONDUCTIVE AND ELECTROCHEMICALLY ERODIBLE WORKPIECE INCLUDING MEANS FOR HOLDING THE WORKPIECE, AN ELECTRODE TOOL FOR SAID MACHINING, MEANS FOR MOVING THE TOOL AND THE WORKPIECE RELATIVELY TOWARD EACH OTHER AND FOR MAINTAINING A WORK GAP THEREBETWEEN, MEANS FOR CIRCULATING AN ELECTROLYTE THROUGH THE WORK GAP, AND A SOURCE OF DIRECT CURRENT ELECTRICITY CONNECTED TO THE ELECTRODE TOOL AND THE WORKPIECE WHEREBY THE WORKPIECE AND THE ELECTRODE TOOL FUNCTION AS AN ANODE AND A CATHODE RESPECTIVELY, THE IMPROVEMENT WHEREIN SAID ELECTRODE TOOL COMPRISES AN ELONGATE ELECTRICALLY CONDUCTIVE TUBE HAVING A WORKING FACE AT ITS OUTER END THROUGH WHICH THE ELECTROLYTE IS PUMPED FOR CIRCULATION TO AND THROUGH THE WORK GAP, AND AT LEAST ONE ELECTRICALLY CONDUCTIVE SOLID CYLINDRICAL ELEMENT OF SUBSTANTIALLY UNIFORM CROSS SECTION ELECTRICALLY CONNECTED TO SAID TUBE, EXTENDING THE LENGTH THEREOF, AND HAVING A CROSS SECTIONAL AREA OF AT LEAST ABOUT 50 PERCENT OF THE CROSS SECTIONAL AREA OF THE BORE OF SAID TUBE, SAID ELEMENT HAVING AN END COPLANAR WITH SAID WORKING FACE.