| 摘要 |
A plasma arc torch mounts an electrode and a nozzle, with a mutual spacing, symmetrically about a common longitudinal axis at one end of the torch adjacent a workpiece. The inner surface of the nozzle has an annular, inwardly-directed projection, located opposite the electrode and at a point of closest spacing between the electrode and the nozzle. The projection, or "angle kink", is characterized by a minimum radius of curvature as compared to the radii of curvature of adjacent portions of the nozzle opposite said electrode. The inner surface is adjacent a central exit passage of the nozzle and the angle kink is spaced from the intersection of the exit port and the inner nozzle. In the preferred form the interior nozzle surface is formed by two conical surfaces each having different slopes with respect to the longitudinal axis so as to form the circumferentially extending angle kink at their plane of intersection.
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