Dual mode plasma arc torch

A plasma arc torch comprising:

• an electrode;
• a tip;
• and
• at least one of a contact start cartridge for a contact start mode and a high frequency start cartridge for a high frequency start mode, the start cartridges being disposed between the electrode and the tip, and the contact start cartridge comprising an initiator in electrical contact with the electrode and in contact with the tip,
• wherein when the plasma arc torch is in a contact start mode, the initiator is movable to separate from the tip and establish a pilot arc between the initiator and the tip, and
• when the plasma arc torch is in a high frequency start mode, the high frequency start cartridge spaces the tip from the electrode such that a pilot arc is established between the electrode and the tip.

A plasma arc torch comprising:

• an electrode;
• a tip;
• and
• a start cartridge disposed between the electrode and the tip,
• wherein the start cartridge spaces the tip from the electrode such that a pilot arc is established between the electrode and the tip when the plasma arc torch is in a high frequency start mode.

A start cartridge for use in a high frequency start plasma arc torch, the start cartridge providing separation and electrical isolation between an electrode and a tip in the plasma arc torch, comprising:

• a plurality of vent holes defining outer vent holes and inner vent holes;
• and
• an internal collar,
• wherein the vent holes provide gas flow to cool the electrode, and a velocity of the gas is increased as the gas flows from the outer vent holes to the inner vent holes, and the internal collar isolates a venting chamber from a plasma chamber within the plasma arc torch.

A plasma arc torch comprising:

• an electrode;
• a tip;
• and
• a start cartridge disposed between the electrode and the tip, the start cartridge comprising:
• a cartridge body;
• a tip seat secured to a distal end of the cartridge body;
• a biasing member disposed within the cartridge body;
• and
• an initiator in electrical contact with the electrode and biased into contact with the tip by the biasing member,
• wherein when the plasma arc torch is in a contact start mode, the initiator is movable against the resilient bias to separate from the tip and establish a pilot arc between the initiator and the tip, and
• when the plasma arc torch is in a high frequency start mode, the start cartridge spaces the tip from the electrode such that a pilot arc is established between the electrode and the tip.

A plasma arc torch comprising:

• an electrode;
• a tip;
• and
• at least one of a contact start cartridge for a contact start mode and a high frequency start cartridge for a high frequency start mode, the start cartridges being disposed between the electrode and the tip, the contact start cartridge comprising:
• a cartridge body;
• a tip seat secured to a distal end of the cartridge body;
• a biasing member disposed within the cartridge body;
• and
• an initiator in electrical contact with the electrode and biased into contact with the tip by the biasing member,
• wherein when the plasma arc torch is in a contact start mode, the initiator is movable against the resilient bias to separate from the tip and establish a pilot arc between the initiator and the tip, and
• when the plasma arc torch is in a high frequency start mode, the start cartridge spaces the tip from the electrode such that a pilot arc is established between the electrode and the tip.

A plasma arc torch comprising:

• an electrode;
• a tip;
• and
• at least one of a contact start cartridge for a contact start mode and a high frequency start cartridge for a high frequency start mode, the start cartridges being disposed between the electrode and the tip,
• the contact start cartridge comprising:
• a cartridge body;
• a tip seat secured to a distal end of the cartridge body;
• a biasing member disposed within the cartridge body;
• and
• an initiator in electrical contact with the electrode and biased into contact with the tip by the biasing member;
• and
• the high frequency start cartridge comprising a plurality of vent holes defining outer vent holes and inner vent holes, an internal collar, and vent passages such that the vent holes and vent passages provide gas flow to cool the electrode, and a velocity of the gas is increased as the gas flows from the outer vent holes to the inner vent holes, and the internal collar isolates a venting chamber from a plasma chamber within the plasma arc torch,
• wherein when the plasma arc torch is in a contact start mode, the initiator is movable against the resilient bias to separate from the tip and establish a pilot arc between the initiator and the tip, and
• when the plasma arc torch is in a high frequency start mode, the high frequency start cartridge spaces the tip from the electrode such that a pilot arc is established between the electrode and the tip.

A contact start torch modified for operation with a high frequency power supply comprising:

• a torch head;
• an electrode electrically connected to a cathode within the torch head;
• a tip electrically connected to an anode within the torch head;
• and
• a dielectric standoff,
• wherein the dielectric standoff is sized such that the contact start torch is operable under high frequency.

A contact start torch modified for operation with a high frequency power supply comprising:

• a torch head;
• an electrode electrically connected to a cathode within the torch head;
• a tip electrically connected to an anode within the torch head
• a movable element disposed between the electrode and the tip that moves to create a pilot arc between the electrode and the tip;
• and
• a dielectric standoff disposed between the cathode and the anode,
• wherein the dielectric standoff is sized such that the contact start torch is operable under high frequency.

A high frequency plasma arc torch modified for operation with a low voltage power supply comprising:

• a torch head;
• an electrode electrically connected to a cathode within the torch head;
• and
• a tip electrically connected to an anode within the torch head;
• wherein either one of both of the electrode and the tip are movable and the plasma arc torch operates under low voltage.

A high frequency plasma arc torch modified for operation with a low voltage power supply comprising:

• a torch head;
• an electrode electrically connected to a cathode within the torch head;
• a movable third element disposed between the electrode and the tip;
• and
• a tip electrically connected to an anode within the torch head;
• wherein the movable third element is movable between the electrode and the tip to form a pilot arc, and the plasma arc torch operates under low voltage.

A method of initiating a pilot arc in a plasma arc torch, the method comprising the steps of:

• disposing a start cartridge comprising an initiator between an electrode and a tip;
• biasing the initiator into contact with the tip;
• providing a source of gas and electric power;
• and
• directing at least a portion of the gas to overcome the bias to separate the initiator from the tip,
• wherein the pilot arc is drawn between the initiator and the tip as the bias is overcome when the plasma arc torch is in a contact start mode, and
• the pilot arc is drawn between the electrode and the tip as the start cartridge spaces the electrode from the tip when the plasma arc torch is in a high frequency start mode.

A method of operating a plasma arc torch in one of a contact start mode and a high frequency start mode, the method comprising the steps of:

• disposing a contact start cartridge comprising an initiator between an electrode and a tip when the plasma arc torch is in the contact start mode;
• biasing the initiator into contact with the tip;
• providing a source of gas and electric power;
• and
• directing at least a portion of the gas to overcome the bias to separate the initiator from the tip,
• wherein the pilot arc is drawn between the initiator and the tip as the bias is overcome when the plasma arc torch is in the contact start mode, and
• disposing a high frequency start cartridge between an electrode and a tip when the plasma arc torch is in the high frequency start mode,
• wherein the pilot arc is drawn between the electrode and the tip as the start cartridge spaces the electrode from the tip in the high frequency start mode.

A method of operating a plasma arc torch in a high frequency mode, the method comprising the steps of:

• disposing a start cartridge between an electrode and a tip;
• and
• providing a source of gas and electric power,
• wherein a pilot arc is drawn between the electrode and the tip as the start cartridge spaces the electrode from the tip in the high frequency start mode.

A method of operating a contact start plasma arc torch modified to operate under high frequency, the method comprising the steps of:

• providing a sufficient dielectric standoff between a cathode body and an anode body within the plasma arc torch sufficient to operate under high frequency;
• and
• providing a source of gas and electric power at a high frequency,
• wherein the contact start plasma arc torch is operable in a high frequency start mode with the dielectric standoff.

A method of operating a high frequency start plasma arc torch modified to operate under low voltage, the method comprising the steps of:

• providing a movable element to the high frequency start plasma arc torch;
• providing a source of gas and electric power at low voltage;
• and
• moving the movable element such that a pilot arc is generated,
• wherein the high frequency start plasma arc torch is operable under low voltage.