Consumable cartridge for a plasma arc cutting system
A frame for a replaceable, unitary consumables cartridge configured for installation into a plasma arc torch. The frame includes a hollow body adapted to receive a translatable contact start electrode. The body has an internal surface and an external surface and includes: a substantially cylindrical metallic core; an electrically insulative overmolded plastic casing at least substantially surrounding a circumference of a distal end of the substantially cylindrical metallic core; and a set of flow passages fluidly connecting the external surface of the hollow body and the internal surface of the hollow body, the flow passages offset to impart a swirling fluid flow pattern to a plasma gases passing therethrough.
1. A frame for a replaceable, unitary consumables cartridge configured for installation into a plasma arc torch, the frame comprising:
a hollow body adapted to receive a translatable contact start electrode, the body having an internal surface and an external surface, the body including:
a substantially cylindrical metallic core;
an electrically insulative overmolded plastic casing at least substantially surrounding a circumference of a distal end of the substantially cylindrical metallic core, and
a set of flow passages fluidly connecting the external surface of the hollow body and the internal surface of the hollow body, the flow passages offset to impart a swirling fluid flow pattern to a plasma gases passing therethrough.
2. The frame of claim 1 wherein the substantially cylindrical metallic core is formed by stamping.
3. The frame of claim 1 wherein the substantially cylindrical metallic core is made of brass.
4. The frame of claim 1 wherein the substantially cylindrical metallic core includes an anodized portion.
5. The frame of claim 1 wherein each flow passage in the set of flow passages is radially offset from the other flow passages.
6. The frame of claim 1 wherein the flow passages have a total cross-sectional area of about one square inch.
7. The frame of claim 1 wherein a first end of the frame is configured to connect to a nozzle.
8. The frame of claim 7 wherein the set of flow passages extends into a further component inseparably attached to a front of the nozzle.
9. A method of cooling a plasma arc torch, the method comprising:
providing a composite consumable having a frame defining a plurality of holes, the composite consumable having integrated components including an electrode, a nozzle and a shield, the holes fluidly connecting an external surface of the frame and an internal surface of the frame, the holes offset to impart a swirling fluid flow pattern to plasma gases passing therethrough;
installing the composite consumable in the plasma arc torch; and
flowing a cooling fluid through the plurality of holes, the cooling fluid forming a fluid flow pattern that cools at least one of the electrode, nozzle or shield,
wherein the frame is adapted to receive a translatable contact start electrode and includes (i) a substantially cylindrical metallic core; and (ii) an electrically insulative overmolded plastic casing at least substantially surrounding a circumference of a distal end of the substantially cylindrical metallic core.
10. The method of claim 9 wherein the substantially cylindrical metallic core is formed by stamping.
11. The method of claim 9 wherein the substantially cylindrical metallic core is made of brass.
12. The method of claim 9 wherein the substantially cylindrical metallic core includes an anodized portion.
13. The method of claim 9 wherein each hole in the plurality of holes is radially offset from the other holes.
14. The method of claim 9 wherein the holes have a total cross-sectional area of about one square inch.
15. The method of claim 9 wherein a first end of the frame is configured to connect to a shield via a shield insulator, the shield thermally coupled to the frame.
16. A method of manufacturing a replaceable, unitary consumables cartridge configured for installation into a plasma arc torch, the method comprising:
providing a hollow body adapted to receive a translatable contact start electrode, the body having an internal surface and an external surface, the body including a substantially cylindrical metallic core;
overmolding an electrically insulative plastic casing on the hollow body, the electrically insulative plastic casing at least substantially surrounding a circumference of a distal end of the substantially cylindrical metallic core, and
providing a set of flow passages fluidly connecting the external surface of the hollow body and the internal surface of the hollow body, the flow passages offset to impart a swirling fluid flow pattern to a plasma gases passing therethrough.