| 摘要 |
A nozzle for a plasma arc torch symmetrically disposed about a nozzle axis and comprising a nozzle orifice centered on the nozzle axis and having a generally cylindrical orifice sidewall; a gas-directing surface symmetrically disposed about the nozzle axis and surrounding said orifice; and an inlet joining said gas-directing surface to said orifice sidewall, said inlet having a variable curvature generated by rotation of a substantially elliptical form about the nozzle axis, wherein the substantially elliptical form at least approximates a portion of an ellipse having a major axis and a minor axis, where the ratio of the major axis to the minor axis is greater than 2:1, further wherein said substantially elliptical form is positioned such that said gas-directing surface is substantially tangent to the ellipse at its intersection therewith, and said orifice sidewall is substantially tangent to the ellipse at its intersection therewith. |
