Arc welding apparatus

Claim 1

AN ARC WELDING APPARATUS COMPRISING A TORCH, AN INERT GAS CONDUIT IN SAID TORCHM A NON-SONSUMABLE ELECTRODE IN SAID CONDUIT AT ONE END OF SAID TORCH, A SUPPLY OF INERT GAS COMMUNICATING WITH SAID CONDUIT, AND A THREE-WAY VALVE IN SAID CONDUIT BETWEEN SAID ELECTRODE AND SAID GAS SUPPLY FOR CONTROLLING THE FLOW OF GAS TO SAID ELECTRODE, SAID VALVE HAVING A CLOSED POSITION FOR PREVENTING FLOW OF GAS TO SAID ELECTRODE, SAID VALVE HAVING A FULLY OPEN POSITION FOR PERMITTING FULL CAPACITY FLOW OF GAS TO SAID ELECTRODE, AND SAID VALVE HAVING AN INTERMEDIATE POSITION FOR PERMITTING RESTRICTED FLOW OF GAS TO SAID ELECTRODE AT A SUFFICIENT RATE TO PROVIDE A PROTECTIVE SHIELDING ATMOSPHERE FOR SAID ELECTRODE WHEN IT COOLS BETWEEN OPERATIONS, SAID THREE-WAY VALVE INCLUDING A ROD HAVING A LONGITUDINAL APERTURE AT EACH END THEREOF COMMUNICATING WITH SAID CONDUIT, A NUMBER OF RADIAL PASSAGEWAYS IN SAID ROD COMMUNICTING WITH ONE OF SAID LONGITUDINAL APERTURES, A NUMBER OF RADIAL RESTRICTED FLOW PASSAGES IN SAID ROD COMMUNICATING WITH SAID ONE LONGITUDINAL APERTURES, A SLIDABLE SLEEVE TELESCOPED OVER SAID ROD, AN ANNULAR PASSAGE IN SAID SLEEVE COMMUNICATING WITH THE OTHER OF SAID LONGITUDINAL APERTURES, SAID ANNULAR PASSAGE BEING DISPOSED AND ARRANGED TO COMMUNICATE WITH SAID RADIAL PASSAGEWAYS AND SAID RESTRICTED FLOW PASSAGES WHEN SAID SLEEVE IS MOVED TO SAID FULLY OPEN POSITION, SAID ANNULAR PASSAGE BEING DISPOSED AND ARRANGED TO COMMUNICATE WITH SAID RESTRICTED FLOW PASSAGE AND TO BE OUT OF COMMUNICATION WITH SAID RADIAL PASSAGEWAY WHEN SAID SLEEVE IS MOVED TO SAID INTERMEDIATE POSITION, AND SAID ANNULAR PASSAGE BEING DISPOSED AND ARRANGED TO BE OUT OF COMMUNICATION WITH SAID RADIAL PASSAGEWAYS AND SAID RESTRICTED FLOW PASSAGES WHEN SAID SLEEVE IS MOVED TO SAID CLOSED POSITION.