Abstract: A plasma torch comprises: a hollow shaft connected to a first supply pipe for a flow of a first gas and to an electrode which is hollow so that it surrounds part of the shaft and forms a first chamber for cooling the electrode and for outfeed of the first gas; a nozzle surrounding the electrode and forming a second chamber, for receiving the first gas for generating plasma, and a third chamber, for the passage of the first gas arriving from the first, cooling chamber through third pipes, to the second chamber, through second pipes which pass through the nozzle. First sealing parts are inserted between the shaft and the nozzle on both sides of the third pipes, forming a sealed zone close to the third pipes.

Abstract: A plasma torch comprises: a hollow shaft connected to a first supply pipe for a flow of a first gas and to an electrode which is hollow so that it surrounds part of the shaft and forms a first chamber for cooling the electrode and for outfeed of the first gas; a nozzle surrounding the electrode and forming a second chamber, for receiving the first gas for generating plasma, and a third chamber, for the passage of the first gas arriving from the first, cooling chamber through third pipes, to the second chamber, through second pipes which pass through the nozzle. First sealing parts are inserted between the shaft and the nozzle on both sides of the third pipes, forming a sealed zone close to the third pipes.

Abstract: The circuit is designed to protect plasma-arc welding or cutting equipment wired for transferred or non-transferred arc operation, using a torch of which the electrode is connected to the negative terminal of the power source and the nozzle to the positive; the arc can be transferred by wiring the work to the positive terminal also. With voltage between at least two of the three connected parts (electrode, nozzle and work) constantly monitored, filtered, and measured against a set point by a comparator of which the output operates a switch controlling the power supply to the equipment, the power source can be deactivated immediately in the event that the monitored voltage registers less than the set point.

Abstract: The circuit comprises a transformer and a rectifier, and is used in conjunction with a torch the electrode of which is wired to one of the output terminals of the rectifier; the nozzle is connected to the remaining terminal by way of a resistor. A comparator monitors passage of the power stage from stand-by to normal non-transferred arc operation, and triggers switch-in of the ground cable by way of which the work is connected to the relative terminal of the rectifier, only after an arc has first been struck between the electrode and the nozzle.

Abstract: 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.