Spark-erosion machine tool for drilling very small holes through thin metal sheets

Claim 1

AN ELELCTRO-EROSION MACHINE FOR PRODUCING MINUTE APERTURES COMPRISING A RESERVOIR OF DIELECTRIC FLUID; AN ANODEIC WORKPIECE IMMERSED IN SAID DIELECTRIC FLUID; A CATHODIC TOOL ADJACENT SAID WORKPIECE; SAID CATHODIC TOOL INCLUDING A PLURALTIY OF PLANAR SHEETS IN SPACED JUXTAPOSITION TO ONE ANOTHER; EACH OF SAID SHEETS INCLUDING A CONTINUOUS UUPPER PORTION AND A DISCONTINUOUS LOWER PORTION DEFINED BY A PLURALITY OF DISCRETE DEPENDING TEETH INTEGRAL WITH SAID UPPER PORTION; SPACER ELEMENTS INTERPOSED IN THE SPACES BETWEEN SAID SHEETS; AND MOUNTING MEANS CLAMPING SAID SHEETS AND SPACER ELEMENTS IN ASSEMBLED RELATIONSHIP WITH SAID SPACER ELEMENTS EXTENDING ONLY BETWEEN THE UPPER PORTIONS OF SAID SHEETS; SAID SHEETS BEING IMMERSED IN SAID DIELECTRIC FLUID WITH SAID DEPENDING TEETH BEING SPACED OPPOSSITE SAID WORKPIECE THEREBY OPERATION OF SAID MACHINE CREATES ELECTRICAL DISCHARGE BETWEEN SAID WORK PIECE AND SAID SHEETS TO BURN ROWS OF MINUTE APERTURES IN SAID WORKPIECE; THE LONGITUDINAL DISTANCE BETWEEN ADJACENT APERTURES INN A ROW BEING DETERMINED BY THE SPACING BETWEEN ADJACENT TEETH ON THE SHEET OPPOSITE THAT ROW AND THE TRANSVERSE DISTANCE BETWEEN ADJACENT ROWS OF APERTURES BEING DETERMINED BY THE THICKNESS OF THE SPACER ELEMENTS BETWEEN CORRESPONDING ADJACENT SHEETS; AND THE LENGTH AND WIDTH OF EACH INDIVIDUAL APERTURE BEING DETERMINED RESPECTIVELY BY THE LENGTH OF THE ASSOCIATED INDIVIDUAL TOOTH AND THE THICKNESS OF THE SHEET FROM WHICH THAT TOOTH DEPENDS.