Electrode for plasma arc torch and method of making the same
First Claim
1. An electrode for supporting an arc in a plasma arc torch, the electrode comprising:
- a metallic holder including, a front end casting portion having an emissive insert cavity and an outer face, and a rear end portion joined to said front end casting portion; and
an emissive insert mounted in said emissive insert cavity, said emissive insert being a metallic material having a relatively low work function, wherein said front end casting portion is a metal selected from silver, gold, platinum, rhodium, indium, palladium, nickel and alloys thereof, and wherein said rear end portion is a metal selected from copper and copper alloys.
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0 Petitions
Accused Products
Abstract
An electrode for supporting an arc in a plasma arc torch. The electrode includes a metallic holder having a front end and a rear end. An emissive insert cavity is formed in the front end. An emissive insert is mounted in the cavity and is a metallic material having a relatively low work function. The front end is a casting made of a metal which is selected from silver, gold, platinum, rhodium, indium, palladium, nickel and alloys thereof. The rear end is a metal selected from copper and copper alloys. A cylindrical post extends inwardly from the front end of the metallic holder. The cylindrical post has an inner-rear tip portion which is a metal selected from copper and copper alloys.
44 Citations
10 Claims
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1. An electrode for supporting an arc in a plasma arc torch, the electrode comprising:
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a metallic holder including, a front end casting portion having an emissive insert cavity and an outer face, and a rear end portion joined to said front end casting portion; and
an emissive insert mounted in said emissive insert cavity, said emissive insert being a metallic material having a relatively low work function, wherein said front end casting portion is a metal selected from silver, gold, platinum, rhodium, indium, palladium, nickel and alloys thereof, and wherein said rear end portion is a metal selected from copper and copper alloys. - View Dependent Claims (2, 3, 4, 5)
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6. A method of fabricating an electrode adapted for supporting an arc in a plasma arc torch, the electrode includes a holder having a front end portion and a rear end portion, the method comprising:
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machining a piece of material to form a rear end portion blank;
forming a notch in one end of the rear end portion blank;
disposing an end of an emissive insert into the notch;
melting a metal selected from silver, gold, platinum, rhodium, indium, palladium, nickel and alloys thereof, and which is to be used to form the front end portion of the holder;
casting the molten metal onto the emissive insert and onto an end of the rear end portion blank so as to form a front end portion blank, such that the front end portion blank and the rear end portion blank constitute a holder blank; and
machining the holder blank to form a finished holder. - View Dependent Claims (7, 8, 9)
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10. An electrode for supporting an arc in a plasma arc torch, the electrode comprising:
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a metallic holder including, a front end portion having an emissive insert cavity and an outer face, and a rear end portion joined to said front end portion;
an emissive insert mounted in said emissive insert cavity, said emissive insert being a metallic material having a relatively low work function; and
casting means for bonding together said front end portion, said rear end portion, and said emissive insert, wherein said front end portion is a metal selected from silver, gold, platinum, rhodium, indium, palladium, nickel and alloys thereof, and wherein said rear end portion is a metal selected from copper and copper alloys.
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Specification