Abstract Electric welding with a transferred arc plasma between an electrode and the parts to be welded under electric voltage of arc transfer, applicable to the welding in one single pass of metal sheets edge-to-edge having a welding thickness comprised between 7 and 14 mm., with an electrode disposed axially with respect to a discharge nozzle for supplying the plasma-producing gas, the said nozzle comprising a convergent and then divergent frusto-conical portion, and in which said electrode has a conical extremity adapted to project on the downstream side of the neck of said discharge nozzle, the convergent portion of said nozzle having a convergence angle greater by 10* to 80* and preferably by 20* to 60* than the convergence angle of the conical extremity of said electrode.
A plasma welding torch with transferred arc, comprising a discharge nozzle for a plasma producing gas and a nonconsumable electrode disposed axially inside the discharge nozzle, said nozzle having in the direction of gas flow therethrough successively an axially convergent frusto-conical portion and an axially divergent frusto-conical portion the largest end of which constitutes the opening of said nozzle, said convergent and divergent portions of said nozzle meeting in a neck whose diameter is 2.5 mm. - 4 mm., said electrode having an extremity of conical form extending axially along said convergent portion and into said axially divergent portion of said nozzle a distance between 0.9 and 2 mm. from said neck.
Claim 2
Dependent Claim
112 words
A plasma welding torch with transferred arc, comprising a discharge nozzle for a plasma producing gas and a nonconsumable electrode disposed axially inside the discharge nozzle, said nozzle having in the direction of gas flow therethrough successively an axially convergent frusto-conical portion and an axially divergent frusto-conical portion the largest end of which constitutes the opening of said nozzle, said convergent and divergent portions of said nozzle meeting in a neck whose diameter is 2.5 mm. - 4 mm., said electrode having an extremity of conical form extending axially along said convergent portion and into said axially divergent portion of said nozzle a distance between 0.9 and 2 mm. from said neck.
Claim 3
Dependent Claim
33 words
A plasma welding torch as claimed in claim 1, said convergent portion of said nozzle having a convergence angle greater by 10*-80* than the convergence angle of the conical extremity of said electrode.
Claim 4
Dependent Claim
33 words
A plasma welding torch as claimed in claim 1, said convergent portion of said nozzle having a convergence angle greater by 20*-60* than the convergence angle of the conical extremity of said electrode.
Claim 5
Dependent Claim
23 words
A plasma welding torch as claimed in claim 1, the angle of said divergent portion of said nozzle being between 40* and 120*.