Powder applying and fusing torch apparatus

Claim 1

A TORCH DEVICE FOR APPLYING AND FUSING METAL POWDER TO A WORKPIECE COMPRISING, A BODY MEMBER HAVING A FIRST PASSAGE THEREIN, A NOZZLE HAVING AN ORIFICE THEREIN DISPOSED IN SAID FIRST PASSAGE AND FORMING AN ASPIRATING VENTURI WITH SAID BODY MEMBER, MEANS FOR CONNECTING SAID NOZZLE TO A SOURCE OF COMBUSTILE FUEL UNDER PRESSURE, A TIP MEMBER HAVING A PASSAGE THEREIN SUPPORTED BY SAID BODY MEMBER AND IN FLUID COMMUNICATION WITH BOTH SAID VENTURI AND SAID FIRST PASSAGE, A POWDER RECEIVING CAVITY FORMED IN SAID BODY MEMBER AND DISPOSED ABOVE SAID FIRST PASSAGE FOR FEEDING POWDER TO SAID VENTUIR, A SECOND PASSAGE IN SAID BODY MEMBER HAVING ONE END THEREOF IN FLUID COMMUNICATION WITH SAID CAVITY, A THIRD PASSAGE IN SAID BODY MEMBER HAVING ONE END THEREOF COMMUNICATING SAID VENTURI AND THE OTHER END THEREOF BEING CLOSED, SAID THIRD PASSAGE COMMUNICATING THE OTHER END OF SAID SECOND PASSAGE INTERMEDIATE THE ENDS OF SAID THIRD PASSAGE FOR PROVIDING A FLOW PATH FOR POWDER FROM SAID CAVITY TO SAID VENTURI, SAID THIRD PASSAGE FROMING A SUBSTANTIAL EXPANSION CHAMBER ABOVE SAID COMMUNICTION BETWEEN SAID THRID PASSAGE AND SAID SECOND PASSAGE FOR PROVIDING ADDITIONAL SPACE FOR EXPANDING GASES IN THE EVENT OF BLOWBACK, AND VALVE MEANS SUPPORTED IN SAID BODY MEMBER HAVING A PORTION THEREOF DISPOSED IN SAID CAVITY FOR ENGAGING SAID OTHER END OF SAID SECOND PASSAGE AND ACTUABLE TO OPEN AND CLOSE COMMUNICATION BETWEEN SAID CAVITY AND SAID SECOND PASSAGE, SO THAT FUEL FLOWING UNDER PRESSURE THROUGH SAID NOZZLE ORIFICE AND SAID TIP MEMBER WILL DRAW POWDER FROM SAID CAVITY THROUGH SAID PASSAGE AND INTO THE FUEL STREAM WHEN SAID VALVE MEANS HAS BEEN ACTUATED TO COMMUNICATE SAID CAVITY WITH SAID SECOND PASSAGE.