Abstract: An electrode for a plasma arc cutting torch which minimizes the deposition of high emissivity material on the nozzle, reduces electrode wear, and improves cut quality. The electrode has a body having a first end, a second end in a spaced relationship relative to the first end, and an outer surface extending from the first end to the second end. The body has an end face disposed at the second end. The electrode also includes at least one passage extending from a first opening in the body to a second opening in the end face. A controller can control the electrode gas flow through the passages as a function of a plasma arc torch parameter. Methods for operating the plasma arc cutting torch with the electrode are disclosed.

Abstract: An electrode for a plasma arc cutting torch which minimizes the deposition of high emissivity material on the nozzle, reduces electrode wear, and improves cut quality. The electrode has a body having a first end, a second end in a spaced relationship relative to the first end, and an outer surface extending from the first end to the second end. The body has an end face disposed at the second end. The electrode also includes at least one passage extending from a first opening in the body to a second opening in the end face.

Abstract: An electrode for a plasma arc cutting torch which minimizes the deposition of high emissivity material on the nozzle, reduces electrode wear, and improves cut quality. The electrode has a body having a first end, a second end in a spaced relationship relative to the first end, and an outer surface extending from the first end to the second end. The body has an end face disposed at the second end. The electrode also includes at least one passage extending from a first opening in the body to a second opening in the end face. A controller can control the electrode gas flow through the passages as a function of a plasma arc torch parameter. Methods for operating the plasma arc cutting torch with the electrode are disclosed.

Abstract: A plasma arc torch that includes a torch body having a nozzle mounted relative to a composite electrode in the body to define a plasma chamber. The torch body includes a plasma flow path for directing a plasma gas to the plasma chamber in which a plasma arc is formed. The nozzle includes a hollow, body portion and a substantially solid, head portion defining an exit orifice. The composite electrode can be made of a metallic material (e.g., silver) with high thermal conductivity in the forward portion electrode body adjacent the emitting surface, and the aft portion of the electrode body is made of a second low cost, metallic material with good thermal and electrical conductivity. This composite electrode configuration produces an electrode with reduced electrode wear or pitting comparable to a silver electrode, for a price comparable to that of a copper electrode.

Abstract: An electrode for a plasma arc torch includes a generally cylindrical elongated body formed of an electrically conductive material. The elongated body includes a proximal end that connects to a power supply and a distal end that receives an emissive element. The electrode can include a flange that is disposed about a surface relative to the distal end of the elongated body, extends radially from the surface of the elongated body, and is utilized to establish a uniform gas flow distribution of a plasma gas flow about the distal end of the elongated body. The electrode can include a contact element that is in electrical communication with the proximal end of the electrode. The contact element includes seating portion that has an outer width that is greater than the outermost diameter of the electrode body and is configured to position the contact element within the plasma arc torch.

Abstract: A plasma arc torch that includes a torch body having a nozzle mounted relative to a composite electrode in the body to define a plasma chamber. The torch body includes a plasma flow path for directing a plasma gas to the plasma chamber in which a plasma arc is formed. The nozzle includes a hollow, body portion and a substantially solid, head portion defining an exit orifice. The composite electrode can be made of a metallic material (e.g., silver) with high thermal conductivity in the forward portion electrode body adjacent the emitting surface, and the aft portion of the electrode body is made of a second low cost, metallic material with good thermal and electrical conductivity. This composite electrode configuration produces an electrode with reduced electrode wear or pitting comparable to a silver electrode, for a price comparable to that of a copper electrode.

Abstract: A component for a contact start plasma arc torch is provided. The component includes a hollow body defining a channel with a longitudinal axis. The channel is capable of slideably receiving an electrode body along the longitudinal axis. The component includes a contact element disposed in the hollow body and includes a first surface and a second surface. The first surface is adapted to facilitate electrical communication with a power supply and the second surface is adapted to physically contact a surface of the electrode body when the plasma arc torch is operated in a transferred arc mode. In addition, the second surface is characterized by the absence of physical contact with the surface of the electrode body when the torch is operated in a pilot arc mode.

Abstract: An electrode for a plasma arc torch includes a generally cylindrical elongated body formed of an electrically conductive material. The elongated body includes a proximal end that connects to a power supply and a distal end that receives an emissive element. The electrode can include a flange that is disposed about a surface relative to the distal end of the elongated body, extends radially from the surface of the elongated body, and is utilized to establish a uniform gas flow distribution of a plasma gas flow about the distal end of the elongated body. The electrode can include a contact element that is in electrical communication with the proximal end of the electrode. The contact element includes seating portion that has an outer width that is greater than the outermost diameter of the electrode body and is configured to position the contact element within the plasma arc torch.

Abstract: An improved electrode for use in a plasma arc torch. The electrode includes an electrode body, a cavity in a front face at a first end of the electrode body, and an insert disposed in the cavity. The first end of the electrode body is formed of high purity copper containing at least 99.81% copper. The insert has a first end and a second end and is formed of a high emissivity material. A diameter of the first end of the insert is less than a diameter of a second end of the insert. An electrode is compressed to retain the insert using radial compression. The invention also includes a method for forming the electrode, and a method of operation of an electrode in a plasma torch.

Abstract: A contact start plasma system is provided that includes a passive pilot arc circuit that decreases the size and cost of the system. The plasma arc system includes a torch body, an electrode having a longitudinally disposed axis and mounted in the body, a nozzle having a longitudinally disposed axis, the nozzle axis being disposed substantially collinearly with the electrode axis, a power supply coupled to the electrode, the nozzle and a workpiece, the power supply providing a current for operating the torch in a pilot arc mode and a transferred arc mode, a gas source coupled to the plasma chamber, the gas source providing gas for operating in a pilot arc mode and a transferred arc mode, and a passive pilot arc circuit coupled between the power supply and the nozzle, the passive pilot arc circuit controlling the operation of the torch in the pilot arc mode. Either the electrode or the nozzle can be translatable for blow-forward or blow-back mode of operation.

Abstract: A method and apparatus for controlling a gas supply to a plasma arc torch uses a proportional control solenoid valve positioned adjacent the torch to manipulate the gas flow to the torch, thereby extending electrode life during arc transfer and shutdown. Swirl ring design can be simplified and gas supply and distribution systems become less complicated. The invention also allows manipulation of shield gas flow to reduce divot formation when making interior cuts. The system can be controlled with a digital signal processor utilizing a feedback loop from a sensor.

Abstract: A method and apparatus for controlling a gas supply to a plasma arc torch uses a proportional control solenoid valve positioned adjacent the torch to manipulate the gas flow to the torch, thereby extending electrode life during arc transfer and shutdown. Swirl ring design can be simplified and gas supply and distribution systems become less complicated. The invention also allows manipulation of shield gas flow to reduce divot formation when making interior cuts. The system can be controlled with a digital signal processor utilizing a feedback loop from a sensor.

Abstract: A method and apparatus for controlling a gas supply to a plasma arc torch uses a proportional control solenoid valve positioned adjacent the torch to manipulate the gas flow to the torch, thereby extending electrode life during arc transfer and shutdown. Swirl ring design can be simplified and gas supply and distribution systems become less complicated. The invention also allows manipulation of shield gas flow to reduce divot formation when making interior cuts. The system can be controlled with a digital signal processor utilizing a feedback loop from a sensor.

Abstract: A method and apparatus for controlling a gas supply to a plasma arc torch uses a proportional control solenoid valve positioned adjacent the torch to manipulate the gas flow to the torch, thereby extending electrode life during arc transfer and shutdown. Swirl ring design can be simplified and gas supply and distribution systems become less complicated. The invention also allows manipulation of shield gas flow to reduce divot formation when making interior cuts. The system can be controlled with a digital signal processor utilizing a feedback loop from a sensor.

Abstract: An output structure for material processing apparatus facilitates field replacement of consumable components, while maintaining important alignments. Contoured surfaces within the output structure mate with corresponding contoured surfaces on the consumable components, thereby facilitating alignment of the consumable components with an axis of the output structure. Material processing apparatus employing such surfaces include lasers and plasma arc torches and, with proper alignment, apparatus performance is improved. Typical consumable components include electrodes, swirl rings, nozzles, and shields. The consumable components can be axially translatable with respect to each other, thereby promoting contact starting of a plasma arc torch. An installation tool for consumable components also serves to align the components with an axis of the output structure.