Drag cup for plasma arc torch
AssigneeThe Lincoln Electric Company
InventorLifeng Luo
Life of this patent
Estimating the term…
Abstract
A drag cup for a plasma arc torch is mounted on a sleeve member of the torch tip having a conical outer surface portion converging toward the torch nozzle and electrode assembly. The drag cup includes a mounting end, a conical portion extending along the conical portion of the sleeve member, and an end radially spaced from and surrounding the torch nozzle and including an end wall spaced axially outwardly of the end of the nozzle and having an opening therethrough coaxial with the plasma jet outlet orifice in the nozzle. The opening through the end wall of the drag cup is 3 to 6 times the size of the nozzle orifice and is large enough to provide a shielding gas flow about the plasma jet without disturbing the jet and, at the same time is small enough to protect the nozzle against molten metal blow-back through the opening.
Claims17
A drag cup for a plasma torch tip assembly including a nozzle having an axis and a cylindrical wall portion having an outer diameter, a nozzle end wall transverse to said axis and a plasma jet outlet orifice through said nozzle end wall coaxial with said axis and having a diameter less than said outer diameter, said drag cup comprising a body portion having axially opposite ends, one of said ends including an annular wall portion for mounting said cup on said tip assembly, a cup end wall at the other end of said body portion transverse to said axis and axially spaced from said nozzle end wall when said drag cup is mounted on said tip assembly, said cup end wall having just one opening therethrough coaxial with said axis and having a diameter larger than said diameter of said orifice and smaller than said outer diameter of said nozzle, said tip assembly including a sleeve member having an axially extending outer surface portion, and said annular wall portion including a plurality of axially extending resilient tabs circumferentially spaced apart about said axis and engaging said axially extending outer surface portion of said sleeve member for releasably mounting said drag cup on said tip assembly.
A drag cup for a plasma torch tip assembly including a nozzle having an axis and a cylindrical wall portion having an outer diameter, a nozzle end wall transverse to said axis and a plasma jet outlet orifice through said nozzle end wall coaxial with said axis and having a diameter less than said outer diameter said drag cup comprising a body portion having axially opposite ends, means at one of said ends including an annular wall portion for mounting said cup on said tip assembly, a cup end wall at the other end of said body portion transverse to said axis and axially spaced from said nozzle end wall when said drag cup is mounted on said tip assembly, said cup end wall having just one opening therethrough coaxial with said axis and having a diameter larger than said diameter of said orifice and smaller than said outer diameter of said nozzle, said cup end wall having axially inner and outer sides, and said opening therethrough including a conically recessed portion on said outer side diverging at an acute angle in the direction from said inner toward said outer side.
Dependencies are inferred from the claim text.