Patent ID: 8258423

Claim:
A plasma torch, comprising: a main torch body; a nozzle; a piston in a piston cavity defined within the main torch body, the piston coupled to an electrode assembly; a first fluid passage and a second fluid passage in communication with the piston cavity, the first fluid passage communicating with a first region of the piston cavity on a first side of the piston, and the second fluid passage communicating with a second region of the piston cavity on a second side of the piston; a connecting pathway configured to conduct fluid between the first and second regions of the piston cavity; the piston being configured to move the electrode assembly between a starting position and an operating position, the electrode assembly contacting the nozzle in the starting position, and the electrode assembly not contacting the nozzle in the operating position; and wherein when fluid flows in a first direction from the first fluid passage into the first region, then through the connecting pathway into the second region, and then out through the second fluid passage, the piston moves the electrode assembly to the starting position, wherein when fluid flows in an opposite second direction from the second fluid passage into the second region, then through the connecting pathway into the first region, and then out through the first fluid passage, the piston moves the electrode assembly to the operating position.