Patent ID: 6063329
Filing Date: 2000-05-16
Classification: B23K,F23D

Abstract:
A mini welding/soldering torch comprising:an oxygen control unit connected to an oxygen storage means to guide oxygen to a gas burner, said oxygen control unit comprising a control rod turned to regulate the flow rate of oxygen, and an oxygen delivery tube for output of oxygen;a fuel gas storage means;a fuel gas control unit connected to said fuel gas storage means to guide fuel gas from said fuel gas storage means to a gas burner, said fuel gas control unit comprising a control rod turned to regulate the flow rate of fuel gas, and a fuel gas delivery tube for output of fuel gas;a gas burner connected to said oxygen delivery tube and said fuel gas delivery tube to receive oxygen and fuel gas from said oxygen control unit and said fuel gas control unit for burning, said gas burner comprising a valve holder fastened to said fuel gas delivery tube by a connecting element, a valve block fastened to said valve holder and sealed with an O-ring, said valve block having a fuel jet at one end thereof, a spring mounted inside said valve block, a stopper supported on said spring inside said valve block and forced by said spring to close the passage between said valve holder and said fuel gas delivery tube, a valve cap covered on said valve block over said fuel jet, said valve cap having an axial hole for output of fuel gas, a non-inflammable porous element mounted inside said valve cap and connected to the fuel jet at said valve block for guiding fuel gas from said valve block to the axial hole at said valve cap, a flow guide fastened to said valve cap to guide out fuel gas, said flow guide comprising an annular groove around the periphery thereof and a fuel gas outlet at said annular groove and a front tip, a rubber ring mounted on said flow guide around the annular groove at said flow guide to buffer output fuel gas for enabling fuel gas to be mixed with oxygen supplied from said oxygen delivery tube, a stepped cylindrical casing fastened to said valve block to hold said valve cap and said flow guide on the inside, said stepped cylindrical casing comprising a radially extended inlet connected to said oxygen delivery tube to guide in oxygen toward the front tip of said flow guide inside said stepped cylindrical casing for mixing with fuel gas, which flows out of the fuel gas outlet at said flow guide, and a jet nozzle assembly fastened to one end of said stepped cylindrical casing remote from said valve block for output of fuel gas-oxygen fuel mixture for burning;wherein if flame is burned backwards and goes into the inside of said jet nozzle assembly, said rubber ring will be melted to block the fuel gas outlet at said flow guide and to stop the supply of fuel gas; said stopper is forced backwards to stop the passage between said valve holder and said fuel gas delivery tube when the inside pressure of said valve block is increased over a predetermined level due to an increase of temperature in said valve block.