Plasma arc torch with coaxial wire feed
First Claim
1. A plasma arc welding apparatus comprising:
- a plasma arc torch, having a hollow non-consumable electrode;
a wire guide, disposed coaxially inside of the plasma arc torch;
wherein the wire guide directs filler wire through the center of the hollow non-consumable electrode during plasma arc welding;
a non-conductive wire guide holder, disposed coaxially inside of the plasma arc torch, for holding the wire guide; and
a coaxial electrode adapter affixed both to the non-conductive wire guide holder and the hollow non-consumable electrode, whereby the wire guide is centered within the hollow non-consumable electrode, thereby preventing the filler wire from contacting the hollow non-consumable electrode during plasma arc welding.
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Accused Products
Abstract
A plasma arc welding apparatus having a coaxial wire feed. The apparatus includes a plasma arc welding torch, a wire guide disposed coaxially inside of the plasma arc welding torch, and a hollow non-consumable electrode. The coaxial wire guide feeds non-electrified filler wire through the tip of the hollow non-consumable electrode during plasma arc welding. Non-electrified filler wires as small as 0.010 inches can be used. This invention allows precision control of the positioning and feeding of the filler wire during plasma arc welding. Since the non-electrified filler wire is fed coaxially through the center of the plasma arc torch'"'"'s electrode and nozzle, the wire is automatically aimed at the optimum point in the weld zone. Therefore, there is no need for additional equipment to position and feed the filler wire from the side before or during welding.
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Citations
36 Claims
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1. A plasma arc welding apparatus comprising:
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a plasma arc torch, having a hollow non-consumable electrode;
a wire guide, disposed coaxially inside of the plasma arc torch;
wherein the wire guide directs filler wire through the center of the hollow non-consumable electrode during plasma arc welding;
a non-conductive wire guide holder, disposed coaxially inside of the plasma arc torch, for holding the wire guide; and
a coaxial electrode adapter affixed both to the non-conductive wire guide holder and the hollow non-consumable electrode, whereby the wire guide is centered within the hollow non-consumable electrode, thereby preventing the filler wire from contacting the hollow non-consumable electrode during plasma arc welding. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A plasma arc welding method, comprising the steps of:
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providing a plasma arc welding torch having a hollow non-consumable electrode and a wire guide disposed coaxially inside of the plasma arc torch;
striking a plasma arc between the torch and a workpiece; and
feeding filler wire coaxially through the wire guide and through the hollow non-consumable electrode into the plasma arc;
whereby the tip of the filler wire is melted by the plasma arc and deposited onto the workpiece;
wherein the plasma arc welding torch further comprises a non-conductive wire guide holder, disposed coaxially inside of the plasma arc torch, for holding the wire guide; and
wherein the plasma arc welding torch further comprises a coaxial electrode adapter affixed both to the non-conductive wire guide holder and the hollow non-consumable electrode, whereby the wire guide is centered within the hollow non-consumable electrode, thereby preventing the filler wire from contacting the hollow non-consumable electrode during plasma arc welding. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34)
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35. A plasma arc welding apparatus comprising:
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a plasma arc torch, having a hollow non-consumable electrode; and
a wire guide, disposed coaxially inside of the plasma arc torch, wherein the wire guide directs a non-electrified filler wire through the center of the hollow non-consumable electrode during plasma arc welding.
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36. A method of welding a workpiece, comprising, in the order presented:
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a) providing a plasma arc welding torch comprising;
a hollow non-consumable electrode;
wire guide means, disposed coaxially with said hollow non-consumable electrode, for guiding and directing a non-electrified filler wire through the center of the hollow non-consumable electrode and into a plasma arc; and
coaxial containment means having a central opening, disposed coaxially around the hollow non-consumable electrode, for containing and directing a coaxial flow of plasma gas around the outside surface of the hollow non-consumable electrode and out through the central opening;
b) coaxially flowing a plasma gas in-between the hollow non-consumable electrode and the coaxial containment means;
c) striking a low current arc between the hollow non-consumable electrode and the coaxial containment means, whereby at least some of the flowing plasma gas becomes ionized;
d) striking a high current plasma arc between the hollow non-consumable electrode and the workpiece;
e) feeding the non-electrified filler wire coaxially through the wire guide means and through the hollow non-consumable electrode into the plasma arc;
f) melting the tip of the non-electrified filler wire with the plasma arc;
g) flowing the melted material from the non-electrified filler wire through the central opening in the coaxial containment means; and
h) depositing the melted material onto the workpiece.
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Specification