Contoured shield orifice for a plasma arc torch

• US 20080083708A1
• Filed: 08/25/2006
• Published: 04/10/2008
• Est. Priority Date: 08/25/2006
• Status: Active Grant

• Current Assignee: Victor Equipment Co. (Enovis Corp.)
• Original Assignee: Thermal Dynamics Corporation (Enovis Corp.)
• Inventors: Conway, Christopher J., Hussary, Nakhleh A., Renault, Thierry R., MacKenzie, Darrin H.
• Granted Patent: US 7,737,383 B2
• Time in Patent Office: Days
• US Class Current: 219/121.5
• CPC Class Codes: H05H 1/34 Details, e.g. electrodes, nozzles
• CPC Class Codes: H05H 1/3457 Nozzle protection devices
• CPC Class Codes: H05H 1/3478 Geometrical details

Abstract

A component for use in a plasma arc torch is provided that includes a continuously contoured surface extending along the component that directs a flow of shield gas at a predetermined angle to result in a specific pierce or cut location on a workpiece. In one form, the component is a shield cap that includes an exit orifice extending through a central portion of the shield cap, the exit orifice defining an inlet portion and an outlet portion, and a continuously contoured surface extending between the inlet portion and the outlet portion. The continuously contoured surfaces may be convergent, divergent, or a combination of convergent and divergent according to the principles of the present disclosure. Additionally, the shield cap may comprise a single, unitary piece or alternately a plurality of pieces or components.

Claims

1. A plasma arc torch comprising:

an electrode disposed within the plasma arc torch and adapted for electrical connection to a cathodic side of a power supply;

a tip positioned distally from the electrode and adapted for electrical connection to an anodic side of the power supply during piloting; and

a shield cap positioned distally from the tip and electrically isolated from the power supply, the shield cap comprising a continuously contoured exit orifice.

2. The plasma arc torch according to claim 1, wherein the continuously contoured exit orifice defines a convergent configuration.

3. The plasma arc torch according to claim 1, wherein the continuously contoured exit orifice defines a divergent configuration.

4. The plasma arc torch according to claim 1, wherein the continuously contoured exit orifice defines a convergent-divergent configuration.

5. The plasma arc torch according to claim 1, wherein the continuously contoured exit orifice defines an angled geometry having a shield angle.

6. The plasma arc torch according to claim 5, wherein the shield angle is between approximately 4°

and approximately 6°

.

7. A shield cap for use in a plasma arc torch comprising:

a body defining a proximal end portion having an attachment area for securing the shield cap to the plasma arc torch; and

a continuously contoured exit orifice extending through a central portion of the body.

8. The shield cap according to claim 7, wherein the continuously contoured exit orifice defines a convergent configuration.

9. The shield cap according to claim 7, wherein the continuously contoured exit orifice defines a divergent configuration.

10. The shield cap according to claim 7, wherein the continuously contoured exit orifice defines a convergent-divergent configuration.

11. The shield cap according to claim 7 further comprising a plurality of vent passageways extending around a peripheral portion of the body.

12. The shield cap according to claim 11, wherein the vent passageways are directed outwardly.

13. The shield cap according to claim 11, wherein the vent passageways are directed inwardly.

14. A shield cap for use in a plasma arc torch comprising an exit orifice extending through a central portion of the shield cap, the exit orifice defining an inlet portion and an outlet portion, and a continuously contoured surface extending between the inlet portion and the outlet portion.

15. The shield cap according to claim 14, wherein the continuously contoured surface defines a convergent configuration.

16. The shield cap according to claim 14, wherein the continuously contoured surface defines a divergent configuration.

17. The shield cap according to claim 14, wherein the continuously contoured surface defines a convergent-divergent configuration.

18. The shield cap according to claim 14, wherein the shield cap comprises a single piece.

19. The shield cap according to claim 14, wherein the shield cap comprises a plurality of pieces.

20. The shield cap according to claim 19, wherein the shield cap comprises:

an outer body;

an insert disposed within the outer body, the insert comprising a continuously contoured exit orifice extending through a central portion of the insert; and

at least one gas passageway disposed between the outer body and the insert.

21. The shield cap according to claim 14 further comprising at least one vent passageway formed through the continuously contoured surface.

22. A component for use in a plasma arc torch comprising a continuously contoured surface extending along the component that directs a flow of shield gas at a predetermined angle to result in a specific pierce or cut location on a workpiece.

23. The component according to claim 22, wherein the component is selected from the group consisting of a shield cap, a gas distributor, a spacer, and a tip.

24. A plasma arc torch comprising a plurality of cooperating continuously contoured surfaces defined by a corresponding plurality of components that direct a flow of shield gas at a predetermined angle to result in a specific pierce or cut location on a workpiece.

25. The plasma arc torch according to claim 24, wherein the plurality of continuously contoured surfaces comprises an outer surface of a tip and an inner surface of a shield cap.

26. The plasma arc torch according to claim 24, wherein the plurality of continuously contoured surfaces comprises an outer surface of a tip and an inner surface of a gas distributor.

27. A method of operating a plasma arc torch comprising directing a shield gas through a central exit orifice of a shield cap along a contoured path relative to a longitudinal axis of the plasma arc torch.

28. The method according to claim 27, wherein the shield gas is directed inwardly.

29. The method according to claim 27, wherein the shield gas is directed outwardly.

30. The method according to claim 27, wherein the shield gas is directed inwardly and outwardly.

31. The method according to claim 27 further comprising venting at least a portion of the shield gas from the shield cap.

32. The method according to claim 31, wherein the venting is in fluid communication with the contoured path.

33. A method of operating a plasma arc torch comprising directing a shield gas along a contoured path relative to a longitudinal axis of the plasma arc torch to direct a flow of shield gas at a predetermined angle, which results in a specific pierce or cut location on a workpiece.