Spot welder

Claim 1

A SPOT WELDER OF THE TYPE WHICH INCLUDES AN UPPER HOUSING THAT SUPPORTS A FORWARDLY EXTENDING FIRST WATERCOOLED ELECTRODE, A LOWER METALLIC HOUSING HAVING TWO LONGITUDINALLY ALIGNED FIRST AND SECOND CYLINDERS THEREIN THAT ARE SEPARATED BY A WALL IN WHICH A CENTRALLY DISPOSED BORE IS FORMED, A PISTON SLIDABLY MOUNTED IN SAID FIRST CYLINDER, A METALLIC PISTON ROD SLIDABLY MOUNTED IN SAID BORE AND CONNECTED ON A FIRST END THEREOF TO SAID PISTON, WHICH PISTON ROD EXTENDS FORWARDLY THROUGH SAID SECOND CYLINDER, A SECOND WATER-COOLED ELECTRODE MOUNTED ON THE FORWARD EXTREMITY OF SAID PISTON ROD, A VALVE FOR CONTROLLING THE FLOW OF COMPRESSED AIR TO AND FROM SAID FIRST CYLINDER TO MOVE SAID SECOND ELECTRODE RELATIVE TO SAID FIRST ELECTRODE, MEANS FOR CONNECTING A FIRST CONDUCTOR OF AN ELECTRIC CIRCUIT TO SAID FIRST ELECTRODE, WHICH SPOT WELDER IS CHARACTERZIED BY: (A) A PLURALITY OF METALLIC ARCUATE SEGMENTS THAT HAVE A HIGH DEGREE OF ELECTRICAL CONDUCTIVITY THAT ARE DISPOSED IN SAID SECOND CYLINDER, WHICH SEGMENTS ENCIRCLE SAID PISTON ROD AND ARE IN CONTACT THEREWITH, SAID SEGMENTS HAVING FLAT REAR FACES THAT ABUT AGAINST THE FORWARD FACE OF SAID WALL, AND OUTWARDLY AND REARWARDLY TAPERING FORWARD FACES; (B) AN OUTWARDLY AND REARWARDLY TAPERING RING THAT ENCIRCLES SAID PISTON ROD IN SAID SECOND CYLINDER AND ENGAGES SAID FORWARD FACES OF SAID SEGMENTS, WITH SAID RING WHEN FORCED REARWARDLY MOVING SAID SEGMENTS INTO PRESSURE CONTACT WITH SAID PISTON ROD; (C) AN APERTURED PLUG DISPOSED IN A FIXED POSITION IN THE FORWARD END OF SAID SECOND CYLINDER, WHICH PLUG SLIDABLY ENGAGES SAID PISTON ROD EXTENDING LONGITUDINALLY THERETHROUGH; (D) SPRING MEANS SAID CYLINDER DISPOSED BETWEEN SAID PLUG AND RING WHICH AT ALL TIMES MAINTAINS A SUBSTANTIAL REARWARDLY DIRECTED FORCE ON SAID RING; (E) ELECTRICALLY INSULATED MEANS FOR SUPPORTING SAID LOWER HOUSING FROM SAID UPPER HOUSING; AND (F) MEANS FOR CONNECTING A SECOND CONDUCTOR OF SAID ELECTRIC CIRCUIT TO SAID LOWER HOUSING, WITH SAID HOUSING, SEGMENTS AND PISTON ROD COOPERATIVELY SUPPLYING ELECTRIC ENERGY FROM SAID ELECTRIC CIRCUIT TO SAID SECOND ELECTRODE TO PERMIT THE WELDING OF TWO OR MORE WORK PIECES WHEN DISPOSED BETWEEN SAID FIRST AND SECOND ELECTRODES AND IN CONTACT THEREWITH.