Abstract: A nozzle for a plasma arc cutting torch is provided with an electrically conductive, heat resistant insert, preferably tungsten or a tungsten alloy. As an alternative to the insert, the material can be coated on the entire inner surface of the nozzle. In either embodiment, the material also can be coated on the outer surface of the nozzle.

Abstract: A plasma torch head has transfer components, including an HF lead and a power lead/gas conduit, which are partially encased in a core fabricated from an elastomer. The core is housed in a rigid shell, which preferably also engages a portion of the transfer components. The shell can be a two-piece shell which is assembled around the core, or can be a single piece cast around the core. The core can be fabricated by securing the transfer components in a mold and filling the mold with an elastomer such as liquid silicone rubber. After curing the elastomer in the mold, the core is stripped from the mold and the shell is formed around the core. In one preferred method, sections of a two-part shell are injection molded from phenolic, placed about the core, and secured together with bolts. In another preferred method, the core is placed in a mold and the mold is filled with a liquid two-part epoxy which is cured in a reduced pressure atmosphere to form a one-piece shell.

Abstract: An electrode for plasma arc torches has a tip body having a tip cavity with a cavity sidewall. An emissive insert having an insert sidewall resides in the tip cavity. A noble metal foil is interposed between the insert sidewall and the cavity sidewall. To fabricate the electrode, a tip body blank is provided, and a tip cavity having a cavity sidewall is formed therein. An emissive insert having an insert sidewall and being loosely insertable into the tip cavity is provided. The insert sidewall is provided with a textured surface with protuberances. A noble metal foil is selected, having an insert-contacting surface and a cavity-contacting surface. The emissive insert and the noble metal foil are placed into the tip cavity of the tip body blank, arranged such that the insert-contacting surface of the foil faces the insert sidewall of the emissive insert, while the cavity-contacting surface of the foil faces the cavity sidewall.

Abstract: To test the alignment of the front wheels of an automotive vehicle, the front wheels of the vehicle are driven onto a pair of spaced, parallel rollers, one of which is driven to effect rotation of the front wheels while the vehicle is standing motionless. The hubcaps are removed and a plane mirror is secured by a magnet to the hub of each front wheel. A laser beam is shone onto each mirror through a central hole in a chart. Means is provided for adjusting the the mirror angularly to tilt its plane relative to the axis of the associated spindle of the vehicle. Each mirror can be adjusted so that its plane is perfectly perpendicular to the axis of the spindle. Then the wheels can be accurately tested for toe, run-out and camber.