Abstract: An electrode body (3) for a plasma torch comprises at least one tapping (15) within which is provided at least one recess (8) extending over all the lengths (d) of the tapping (15), and at least one downstream portion defining a recess (16) located between the upstream tapped portion and the bottom of the electrode body (3)

Abstract: Male/female assembly (11) for a plasma torch comprising an electrode body (3) and an electrode carrier (4), in which:the electrode body (3) comprises at least one tapping (15) within which is provided at least one recess (8) extending over all the lengths (d) of said tapping (15), and at least one downstream portion defining a recess (16) located between the upstream tapped portion and the bottom of the electrode body (3), andthe electrode carrier (4) comprises, on its external peripheral surface, at least one gauge (4") having at least locally a profile corresponding to the profile of said at least one recess (8) of the electrode body (3) and at least one screw thread (15'), said gauge (4") being located between the downstream end of the electrode carrier (4) and said screw thread (15).

Abstract: Plasma torch (1) equipped with a torch head (1') including a nozzle holder (10) and a nozzle (4), the nozzle (4) being fixed to the nozzle holder (10) by the use of fixing elements (14). Safety electrical switch unit (3) controls the electric current supplied to the torch head (1'). A removable protective shroud (5) surrounds the torch head (1') and comprises, on the one hand, at least one actuating element (6) capable of interacting with the safety electrical switch unit (3) in order to make it possible to supply electric current to the torch head (1') and, on the other hand, retaining elements comprising a spring clip (8) capable of interacting with a circular groove of the nozzle (4) to allow the protective shroud (5) to be integrated with the nozzle (4). Such a plasma torch is useful for welding or cutting a piece of metal.

Abstract: The plasma welding or cutting system comprises in particular a torch (2), a nozzle (3), a gas supply for the torch for supplying the torch with a plasma-producing gas, and an electrical supply for the torch for creating, maintaining or breaking an electric plasma welding or cutting arc. According to the invention, the system further comprises a delay system connected, on one hand, to the electrical supply for the torch, and, on the other hand, to the gas supply for the torch, the delay system being, when the torch is supplied by the gas supply and the electrical supply, responsive to the breaking of the electric arc of the torch and causing the closure of the gas supply after a predetermined period of time following the breaking of the electric arc so as to achieve the cooling of the torch and the maintenance of the nozzle against its seat during said period of time.

Abstract: The plasma welding or cutting torch comprises a hollow torch body (1) whose interior is connected to a source of plasma-producing gas, an electrode (2) disposed inside the body (1) and electrically connected to an electrical supply conductor, and a nozzle (3) provided with a plasma outlet orifice (34). This torch is characterized in that it comprises a cartridge (60) which cannot be disassembled and comprises an annular skirt (4) assembled by screwing with the torch body (1) and having a seat (18b) for the nozzle (3) which is freely slidably mounted in the skirt (4) and applied against the seat (18b) solely by the pressure of the plasma-producing gas.

Abstract: For forming the plasma arc there is used nitrogen protoxide in the liquid state which is conducted through a valve (12) to an expansion orifice (33) which produces a cooling effect on the electrode (5,6). Applications in particular in plasma arc torch cutting.

Abstract: This invention relates to plasma torches in which, the gas entering the electrode holder is divided into a plasmagenic gas flow and into a cooling gas flow by two series of openings drilled in one and the same metal element forming the electrode holder.

Abstract: There is proposed as a plasma-producing gas, a gas containing the elements nitrogen and oxygen chemically combined in a nitrogen oxide and in particular nitrous oxide. These plasma-producing gases or mixture of gases stored in a bottle, a frame, a container, a tank, in the gaseous or liquid form at ambient or cryogenic temperature, are applicable to the plasma arc cutting of electrically conductive materials.

Abstract: The arc is struck by the initial short circuit between the electrode (2), the nozzle (3) and the work piece (7) by the excitation by a very low voltage source (31) of a relay (48) causing (between 43 and 42) the closure of the main contact (15), after which the relay (48) is maintained in its state by the welding or cutting current generating a voltage at the terminals of the inductance (23). Application in the control of a torch which is ignited by a short circuit between the electrode, nozzle and the torch.

Abstract: The plasma torch comprises a hollow torch body whose interior is connected to a source of plasma-producing gas, a hollow electrode lodged inside this body and electrically connected to an electric supply conductor, and a nozzle provided with an orifice for the outlet of the plasma. The feature of the invention is that the torch comprises a detachable annular skirt (4) which is assembled by a screwed connection with the torch body (1) and has two axially spaced-apart seats (17c,18b) respectively for the electrode (2) and the nozzle (3), and the electrode and the nozzle are freely slidably mounted in the skirt (4) and applied against their respective seats (17c,18b) solely under the action of the pressure of the plasma-producing gas.

Abstract: The invention relates in particular to plasma cutting. The nozzle (5) is freely slidably mounted in the torch body so as to come into contact with the electrode if the torch is applied against the work piece (16). By disengaging the torch, an arc is struck between the electrode and the nozzle and then transferred to the work piece. Application in particular to low-power plasma torches.

Abstract: This invention relates to arc working torches.To prevent the operator from touching the live electrode, the free end of the torch is provided with a cowling formed by a protective skirt on the one hand and on the other hand by a tilting stirrup hinged on this skirt which engages on the torch body while closing an electrical circuit forming part of the safety circuit of the torch. The invention is applied to manual plasma cutting torches.

Abstract: A cathode for an electron gun in which a lanthanum hexaboride cap has an internal recess which accommodates a pyrolytic graphite heater element. The cap is cup-shaped, while the heater element is in the form of a frustum of a cone and is resiliently maintained in abutting relationship with the cap by a corrugated tubular member and an assembly of rigid tubes. A cylindrical shell surrounds the periphery of the cap, and a pair of generally conical shielding elements are located in position to intercept stray thermal radiation from the heater element. All of these cathode components are supported in coaxial relationship with each other within the electron gun.

Abstract: A valve which preserves the vacuum between a gun and a welding enclosure in an electron-bombardment.The valve contains a chamber which communicates with the gun and the enclosure via opposing orifices, with a sliding piston provided with a passage coming into line with the orifices when the valve is in the open, or welding position, the piston being actuated by means employing fluid.The invention is applicable to electron-bombardment welding machines and in particular to machines fitted with visual means for inspecting the parts to be welded.