Apparatus and method for improved assembly concentricity in a plasma arc torch
First Claim
1. A plasma arc torch comprising:
- first and second consumable components forming a plasma chamber therebetween in which an arc may be formed;
a torch body having an interior surface forming a circumferential groove and a bore in which said first component is disposed;
a first spring element disposed between said body interior surface and said first component in said body groove for providing radially directed forces therebetween to radially center said first component in said body bore;
a cathode block having an interior surface forming a circumferential groove and a bore in which said second component is disposed; and
a second spring element disposed between said block interior surface and said second component in said block groove for providing radially directed forces therebetween to radially center said second component in said block bore, wherein said body bore and said block bore are substantially concentrically aligned thereby substantially concentrically aligning said first and second components.
8 Assignments
0 Petitions
Accused Products
Abstract
Disclosed is a method and structure for improving alignment of a plasma arc with an axial centerline of a plasma arc torch. At least one of an electrode and nozzle are mounted in respective bores of a cathode block and torch body using a radial spring element. By concentrically machining the bores along an axial centerline of the torch and centering the consumable components within the bores using the spring elements, an insert disposed in a tip of the electrode is axially aligned with an orifice formed in a tip of the nozzle. Asymmetric wear of the nozzle orifice due to a skewed arc path is markedly reduced or eliminated. The torch may be employed in computer controlled cutting and marking systems to produce components or workpieces with reduced dimensional and angular errors.
-
Citations
14 Claims
-
1. A plasma arc torch comprising:
-
first and second consumable components forming a plasma chamber therebetween in which an arc may be formed; a torch body having an interior surface forming a circumferential groove and a bore in which said first component is disposed; a first spring element disposed between said body interior surface and said first component in said body groove for providing radially directed forces therebetween to radially center said first component in said body bore; a cathode block having an interior surface forming a circumferential groove and a bore in which said second component is disposed; and a second spring element disposed between said block interior surface and said second component in said block groove for providing radially directed forces therebetween to radially center said second component in said block bore, wherein said body bore and said block bore are substantially concentrically aligned thereby substantially concentrically aligning said first and second components. - View Dependent Claims (2, 3)
-
-
4. A plasma arc torch comprising:
-
an electrode and a nozzle forming a plasma chamber therebetween in which an arc may be formed; a cathode block having an interior surface forming a circumferential groove and a bore in which said electrode is disposed; a first spring element disposed between said block interior surface and said electrode in said block groove for providing radially directed forces therebetween to radially center said electrode in said block bore; a torch body having an interior surface forming a circumferential groove and a bore in which said nozzle is disposed; and a second spring element disposed between said body interior surface and said nozzle in said body groove for providing radially directed forces therebetween to radially center said nozzle in said body bore, wherein said block bore and said body bore are substantially concentrically aligned thereby substantially concentrically aligning said electrode and said nozzle.
-
-
5. A method of concentrically axially aligning first and second consumable components which form a plasma chamber therebetween when installed in a plasma arc torch, the method comprising the steps of:
-
providing a torch assembly comprising first and second inner surfaces forming first and second generally axially concentric bores in which said first and second components are respectively disposed upon assembly of the torch; generating a circumferential groove along each of said interior surfaces; disposing a spring element in each of said grooves for providing radially directed forces between said grooved surfaces and said respective first and second components when disposed therein; and disposing said first and second components into respective first and second bores thereby compressing respective spring elements resulting in concentric axial alignment of said first and second components. - View Dependent Claims (6, 7, 8)
-
-
9. A nozzle for a plasma arc torch comprising:
-
an outer surface for reacting against a circumscribing radial spring element when installed in the torch, wherein said surface is radially dimensioned along an axial extent thereof to compress sufficiently said spring element to radially center said nozzle in the torch; and an end contiguous with said surface having a minimum diametral dimension equal to or less than about an installed nominal bore diameter of said spring element. - View Dependent Claims (10, 11)
-
-
12. An electrode for a plasma arc torch comprising:
-
an outer surface for reacting against a circumscribing radial spring element when installed in the torch, wherein said surface is radially dimensioned along an axial extent thereof to compress sufficiently said spring element to radially center said electrode in the torch; and an end contiguous with said surface having a minimum diametral dimension equal to or less than about an installed nominal bore diameter of said spring element. - View Dependent Claims (13, 14)
-
Specification