The present invention relates to a plasma-generating device, comprising an anode, a cathode and at least one intermediate electrode, said intermediate electrode being arranged at least partly between said anode and said cathode, and said intermediate electrode and said anode forming at least a part of a plasma channel which has an opening in said anode. Further, the plasma-generating device comprises at least one coolant channel which is arranged with at least one outlet opening which is positioned beyond, in the direction from the cathode to the anode, said at least one intermediate electrode, and the channel direction of said coolant channel at said outlet opening has a directional component which is the same as that of the channel direction of the plasma channel at the opening thereof. The invention also concerns a plasma surgical device and use of such a plasma surgical device.

A plasma arc torch system comprising a plasma arc torch is provided. The torch includes an electrode, a nozzle, a vent passage and a shield. The nozzle is spaced from the electrode to define a plasma chamber therebetween. The plasma chamber is configured to receive a plasma gas. The vent passage, disposed in the nozzle body, is configured to divert a portion of the plasma gas exiting the plasma chamber from a nozzle exit orifice. The shield is spaced from the nozzle to define a flow region therebetween. The flow region is configured to (i) receive a liquid and (ii) expel the liquid along with a plasma arc substantially surrounded by the liquid via a shield exit orifice.

A non-transferred plasma arc system, which is provided with a non-transferred plasma torch (1) that is provided with a non-consumable electrode (101) as a negative electrode and an insert chip as a positive electrode, the insert chip being cooled by a circulated coolant (W) and the insert chip releasing a plasma arc onto a workpiece. The plasma arc torch (1) comprises a TIG welding torch (100) that is provided with the non-consumable electrode (101), whereby an arc is generated between the workpiece and said electrode (101), and a torch nozzle (105), which releases a shield gas toward an arc-generated weld pool of the workpiece. The plasma arc torch (1) is provided with an attachment (51) that is detachably attached to the TIG welding torch (100) while surrounding the periphery of the torch nozzle (105) and that functions as the insert chip, whereby a non-transferred plasma arc is inexpensively and easily used.

One object of the present invention is to provide a plasma welding method capable of performing plasma welding while restraining initial investment in a welding device, and the present invention provide a plasma welding method includes a pilot arc generation step in which a pilot arc is generated between the electrode and the insert chip by supplying a first pilot gas which is easily converted into a plasma state between the electrode and the insert chip while supplying a shield gas between the insert chip and the shield cap; and a first welding step in which, after the pilot arc generation step, a main arc is generated between the electrode and the workpiece by electrically disconnecting the plus terminal and the insert chip by the first selector switch while supplying the first pilot gas and the shield gas.

The present invention relates to a plasma-generating device, comprising an anode, a cathode and at least one intermediate electrode, said intermediate electrode being arranged at least partly between said anode and said cathode, and said intermediate electrode and said anode forming at least a part of a plasma channel which has an opening in said anode. Further, the plasma-generating device comprises at least one coolant channel which is arranged with at least one outlet opening which is positioned beyond, in the direction from the cathode to the anode, said at least one intermediate electrode, and the channel direction of said coolant channel at said outlet opening has a directional component which is the same as that of the channel direction of the plasma channel at the opening thereof. The invention also concerns a plasma surgical device and use of such a plasma surgical device.

Plasma gas is ejected from inner gas ejection ports that are formed in a downstream side housing, and nitrogen gas is supplied as protective gas to a protective gas source between a housing and a cover section. Nitrogen gas is sucked in accompanying exhaust from inner gas ejection ports of plasma gas, and is ejected from the outer gas ejection ports. In this case, since a layer of nitrogen gas is formed in the periphery of plasma gas, it is possible to make it difficult to bring the plasma gas into contact with air, and it is possible to make it difficult to react a reactive species such as a radical in the plasma gas, oxygen in the air, and the like.

The present invention relates to a plasma-generating device, comprising an anode, a cathode and at least one intermediate electrode, said intermediate electrode being arranged at least partly between said anode and said cathode, and said intermediate electrode and said anode forming at least a part of a plasma channel which has an opening in said anode. Further, the plasma-generating device comprises at least one coolant channel which is arranged with at least one outlet opening which is positioned beyond, in the direction from the cathode to the anode, said at least one intermediate electrode, and the channel direction of said coolant channel at said outlet opening has a directional component which is the same as that of the channel direction of the plasma channel at the opening thereof. The invention also concerns a plasma surgical device and use of such a plasma surgical device.

This specification describes systems, methods, and architectures related to generating a plasma shield for laser operations. An example system for generating a plasma shield includes a laser head for directing a laser beam towards a target area on a workpiece. The path of the laser beam from the laser head to the target area on the workpiece is substantially surrounded by a plasma shield, which may form a gas-impermeable barrier. The plasma shield is configured to prevent the ingress of atmospheric or environmental gases, for example oxygen, into an area which would allow the gas to be in contact with the area of the workpiece being interacted with by a laser beam. The shape or location of the plasma shield may be controlled or altered using a magnetic field.

A non-transferred plasma arc system, which is provided with a non-transferred plasma torch (1) that is provided with a non-consumable electrode (101) as a negative electrode and an insert chip as a positive electrode, the insert chip being cooled by a circulated coolant (W) and the insert chip releasing a plasma arc onto a workpiece. The plasma arc torch (1) comprises a TIG welding torch (100) that is provided with the non-consumable electrode (101), whereby an arc is generated between the workpiece and said electrode (101), and a torch nozzle (105), which releases a shield gas toward an arc-generated weld pool of the workpiece. The plasma arc torch (1) is provided with an attachment (51) that is detachably attached to the TIG welding torch (100) while surrounding the periphery of the torch nozzle (105) and that functions as the insert chip, whereby a non-transferred plasma arc is inexpensively and easily used.

A method for using a plasma torch includes delivering a plasma gas through a plasma gas flow channel of a plasma torch while ionizing the plasma gas to produce a plasma arc that extends between the electrode and the workpiece. Additionally, shield fluid is delivered through a shield flow channel at a first pressure. A piercing operation to produce a pierce hole in the workpiece using the plasma arc is initiated while the shield fluid is delivered through the shield flow channel at the first pressure. After conducting the piercing operation for an amount of time, the shield fluid is delivered to the shield flow channel at a second pressure that is higher than the first pressure. Subsequent to the piercing operation, performing a cutting operation that forms a cut in the workpiece that originates at and extends away from a boundary of the pierce hole.