| 摘要 |
The invention relates to a torch for plasma arc welding and cutting operations carried out on metal, which comprises a hollow grip, to which two power supply conductors are connected together with tubes supplying plasma-forming gas and coolant, a cylindrical electrode rigidly attached to the forward end of the grip and wired to the negative pole of the power supply, and a tapered nozzle positioned forward of the electrode and fitted to a metal sleeve which is wired to the positive pole of the power supply, ensheathed by insulating material, and capable of sliding in relation to the electrode. Plasma-forming gas is injected into a space between the electrode and the sleeve, channelled through to a constricting chamber accommodating the tip of the electrode, and ionized by an arc struck between the electrode and the nozzle before being projected from the orifice in the nozzle.
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