Abstract: An electrode for a contact start plasma arc torch includes an elongated electrode body formed of an electrically conductive material. The electrode body is movable relative to the torch. A resilient element, contacting a proximal end of the electrode body, is used for imparting a separation force to the electrode body. The electrode body is adapted to overcome the separation force and engage a contact element of the torch when the torch is operated in a transferred arc mode.

Abstract: An electrode for a contact start plasma arc torch includes an elongated electrode body formed of an electrically conductive material. The electrode body is movable relative to the torch. The electrode and torch can include a contact element having a first surface in electrical communication with the power contact and a second surface characterized by (i) physical contact with the electrode body during transferred arc mode and (ii) absence of physical contact with the electrode body during initiation of a pilot arc.

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 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: 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 method and apparatus for a plasma torch system having a plasma torch tip configuration that includes a nozzle, an electrode, and a control unit for controlling a composition of the shield gas flow, such that while cutting the contour the shield gas flow comprises a first shield gas composition and while cutting the hole the shield gas flow comprises a second shield gas composition.

Abstract: A method and apparatus for a plasma torch system having a plasma torch tip configuration that includes a nozzle, an electrode, and a control unit for controlling a composition of the shield gas flow, such that while cutting the contour the shield gas flow comprises a first shield gas composition and while cutting the hole the shield gas flow comprises a second shield gas composition.

Abstract: A method and apparatus for a plasma torch system having a plasma torch tip configuration that includes a nozzle, an electrode, and a control unit for controlling a composition of the shield gas flow, such that while cutting the contour the shield gas flow comprises a first shield gas composition and while cutting the hole the shield gas flow comprises a second shield gas composition.

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 of using a coolant tube in a liquid cooled plasma arc torch is provided. The method includes installing the coolant tube and a first electrode in the plasma arc torch. The method also includes biasing, by a first coolant flow, a biasing surface of the coolant tube against the first electrode, such that the coolant tube translates axially along the longitudinal axis to contact the first electrode. The biasing by the first coolant flow defines a first distance in an axial direction between the O-ring of the coolant tube and a proximal end of the first electrode. The method further includes removing the first electrode from the plasma arc torch and installing a second electrode in the torch. The method includes biasing, by a second coolant flow, the biasing surface of the coolant tube against the second electrode, such that the coolant tube translates axially along the longitudinal axis to contact the second electrode.

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.