Method of producing electric contact fingers

Claim 1

IN A METHOD OF PRODUCING AN ELECTRIC CONTACT FINGER, THE STEPS WHICH COMPRISE: PROVIDING A FLAT BAR OF HARD DRAWN COPPER, PRODUCING THROUGH OPENINGS IN THE BAR IN ACCURATE LOCATIONS PRESCRIBED BY THE MOUNTING UPON WHICH THE FINGER IS TO BE SUPPORTED WHEN IN USE, BRAZING A CONTACT BUTTON TO A FACE OF THE BAR, THE HEAT OF SAID BRAZING HAVING AN ANNEALING EFFECT UPON THE COPPER, SECURING THE BAR IN A RIGID HOLDER THAT SNUGLY CONFINES OPPOSITE SIDE EDGES AND PLUGS SAID OPENINGS WITH RIGID UNYIELDING MATERIAL, AND THEN, WHILE SO SECURED AGAINST DIMENSIONAL CHANGES, SUBJECTING AT LEAST ONE FACE OF THE BAR TO SIMULTANEOUS PERPENDICULARLY APPLIED PRESSURE IN A MULTIPLICITY OF MINUTE CLOSELY ADJACENT SPOTS, THE PRESSURE BEING OF SUFFICIENT MAGNITUDE TO CAUSE DEFORMATION OF THE METAL INTO A PATTERN OF DEPRESSIONS AND TO CAUSE COLD FLOW INTO THE REGIONS BETWEEN AND DIRECTLY ADJACENT TO SAID DEPRESSIONS, SAID PRESSURE TREATMENT SERVING TO REHARDEN THE COPPER, CONFINING OF THE SIDE EDGES OF THE BAR SERVING TO PREVENT ALTERATION IN THE WIDTH OF THE BAR AS A RESULT OF THE APPLICATION OF SAID PRESSURE AND TO HARDEN SAID SIDE EDGES BY RESTRAINING THEIR NORMAL TENDENCY TO EXPAND OUTWARDLY.