Liquid cooled plasma arc torch

Patent metadata

Field	Value
Publication number	US-11997779-B2
Application number	US-202017060203-A
Country	US
Kind code	B2
Filing date	Oct 1, 2020
Priority date	Nov 8, 2019
Publication date	May 28, 2024
Grant date	May 28, 2024

Abstract

A plasma arc torch includes a cathode extending along an axis of the torch, a pilot arc conductor, and a nozzle body. A first fluid conduit and second fluid conduit extend parallel to the axis of the torch. A first offset fitting includes a first duct coupled to and in fluid communication with the first fluid conduit, and a second duct in fluid communication with the first duct and outwardly radially offset from the first duct and extending away from the first duct in a proximal direction. A second offset fitting includes a third duct coupled to and in fluid communication with the second fluid conduit, and a fourth duct in fluid communication with the third duct and outwardly radially offset from the third duct and extending away from the third duct in the proximal direction. A spring compression plug electrically connects the pilot arc conductor to the nozzle body.

First claim

What is claimed is:

1. A plasma arc torch, comprising:
a cathode extending along an axis of the torch in a distal direction toward an electrode attached to the cathode, and having a first plurality of cooling liquid apertures;
a nozzle;
a nozzle body having an internal cooling liquid channel that conveys cooling liquid toward the nozzle, wherein the nozzle body is an anode of the plasma arc torch;
an inner isolator having a second plurality of cooling liquid apertures in fluid communication with the first plurality of cooling liquid apertures;
an outer isolator radially offset from the inner isolator to form an interstitial space through which the cooling liquid is conveyed into nozzle body, wherein a distal terminal end of the outer isolator is radially offset from the inner isolator such that the interstitial space extends to the distal terminal end of the outer isolator and the inner isolator extends distal of the outer isolator and the outer isolator extends proximal of the inner isolator, and wherein the inner isolator and the outer isolator electrically insulate the nozzle body from the cathode;
a cooling liquid return conduit; and
a cooling liquid return offset fitting including a first cooling liquid return duct in fluid communication with the cooling liquid return conduit, and a second cooling liquid return duct in fluid communication with the first cooling liquid return duct, wherein the first cooling liquid return duct is coupled to the cooling liquid return conduit, and the second cooling liquid return duct is outwardly radially offset from the first cooling liquid return duct and extends away from the first cooling liquid return duct in a proximal direction, parallel to the axis of the torch.

2. The plasma arc torch of claim 1 , wherein the internal cooling liquid channel is less than one inch long and less than 0.1 inch in diameter.

3. The plasma arc torch of claim 1 , wherein a proximal terminal end of the inner isolator contacts an inner wall of the outer isolator, and the second plurality of cooling liquid apertures is located distal of the proximal terminal end of the inner isolator.

4. The plasma arc torch of claim 1 , wherein the cooling liquid return offset fitting is made from an electrically insulating material.

5. The plasma arc torch of claim 4 , wherein plasma arc torch comprises a torch head and a torch base, and the torch head comprises a threaded connection collar for attaching the torch head to the torch base.

6. The plasma arc torch of claim 1 , further comprising:
a plasma gas conduit; and
a plasma gas offset fitting including a first plasma gas duct in fluid communication with the plasma gas conduit, and a second plasma gas duct in fluid communication with the first plasma gas duct, wherein the first plasma gas duct is coupled to the plasma gas conduit, and the second plasma gas duct is outwardly radially offset from the first plasma gas duct and extends away from the first plasma gas duct in a proximal direction away from the electrode, parallel to the axis of the torch.

7. The plasma arc torch of claim 1 , further comprising:
a shield gas conduit; and
a shield gas offset fitting including a first shield gas duct in fluid communication with the shield gas conduit, and a second shield gas duct in fluid communication with the first shield gas duct, wherein the first shield gas duct is coupled to the shield gas conduit, and the second shield gas duct is outwardly radially offset from the first shield gas duct and extends away from the first shield gas duct in a proximal direction away from the electrode, parallel to the axis of the torch.

8. The plasma arc torch of claim 1 , further comprising:
a pilot arc conductor; and
a spring compression plug electrically connecting the pilot arc conductor to the nozzle body.

9. A plasma arc torch, comprising:
a cathode extending along an axis of the torch in a distal direction toward an electrode attached to the cathode;
a pilot arc conductor;
a nozzle body that is an anode of the plasma arc torch;
a plasma gas conduit;
a shield gas conduit;
a cooling liquid return conduit;
a plasma gas offset fitting including a first plasma gas duct in fluid communication with the plasma gas conduit, and a second plasma gas duct in fluid communication with the first plasma gas duct, wherein the second plasma gas duct is outwardly radially offset from the first plasma gas duct and extends away from the first plasma gas duct in a proximal direction away from the electrode, parallel to the axis of the torch;
a shield gas offset fitting including a first shield gas duct in fluid communication with the shield gas conduit, and a second shield gas duct in fluid communication with the first shield gas duct, wherein the second shield gas duct is outwardly radially offset from the first shield gas duct and extends away from the first shield gas duct in the proximal direction, parallel to the axis of the torch;
a cooling liquid return offset fitting including a first cooling liquid return duct in fluid communication with the cooling liquid return conduit, and a second cooling liquid return duct in fluid communication with the first cooling liquid return duct, wherein the second cooling liquid return duct is outwardly radially offset from the first cooling liquid return duct and extends away from the first cooling liquid return duct in the proximal direction, parallel to the axis of the torch; and
a spring compression plug electrically connecting the pilot arc conductor to the nozzle body.

10. The plasma arc torch of claim 9 , wherein the cathode includes a first plurality of cooling liquid apertures, and the nozzle body includes an internal cooling liquid channel that conveys cooling liquid toward a nozzle of the torch, wherein the torch further comprises:
an inner isolator having a second plurality of cooling liquid apertures in fluid communication with the first plurality of cooling liquid apertures; and
an outer isolator radially offset from the inner isolator to form an interstitial space through which the cooling liquid is conveyed into nozzle body, wherein a distal terminal end of the outer isolator is radially offset from the inner isolator such that the interstitial space extends to the distal terminal end of the outer isolator and the inner isolator extends distal of the outer isolator and the outer isolator extends proximal of the inner isolator, and wherein the inner isolator and the outer isolator electrically insulate the nozzle body from the cathode.

11. The plasma arc torch of claim 10 , wherein the internal cooling liquid channel is less than one inch long and less than 0.1 inch in diameter.

12. The plasma arc torch of claim 10 , wherein a proximal terminal end of the inner isolator contacts an inner wall of the outer isolator, and the second plurality of cooling liquid apertures is located distal of the proximal terminal end of the inner isolator.

13. The plasma arc torch of claim 9 , wherein the plasma gas offset fitting, the shield gas offset fitting, and the cooling liquid return offset fitting are integrally formed from an electrically insulating material.

14. The plasma arc torch of claim 10 , wherein plasma arc torch comprises a torch head and a torch base, and the torch head comprises a threaded connection collar for attaching the torch head to the torch base.

Assignees

• Lincoln Global Inc

Inventors

• Namburu Praveen K
• Severance Jr Wayne S
• Train Matthew E

Classifications

• H05H1/34 Primary

  Details, e.g. electrodes, nozzles · CPC title

• B23K10/006 Primary

  Control circuits therefor · CPC title

• B23K26/1435

  involving specially adapted flow-control means · CPC title

• B23K31/10

  relating to cutting or desurfacing · CPC title

• B23Q15/08

  Control or regulation of cutting velocity (B23Q15/12 takes precedence) · CPC title