Vented shield system for a plasma arc torch

• US 20040169018A1
• Filed: 02/27/2003
• Published: 09/02/2004
• Est. Priority Date: 02/27/2003
• Status: Active Grant

• Current Assignee: Victor Equipment Co. (Enovis Corp.)
• Original Assignee: Thermal Dynamics Corporation (Enovis Corp.)
• Inventors: Hewett, Roger W., Horner-Richardson, Kevin D., Brasseur, Jonathan
• Granted Patent: US 6,914,211 B2
• Time in Patent Office: Days
• US Class Current: 219/121.5
• CPC Class Codes: B23K 10/00 Welding or cutting by means of a plasma
• 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

Vented shield systems for plasma arc torches are provided that comprise a shield cup body defining a distal end portion, a vented retainer secured to the distal end portion of the shield cup body, and a shield cap secured to the vented retainer. The vented retainer defines at least one vent passageway that directs a flow of secondary gas inward toward the shield cap, and the vented shield system blocks at least a portion of molten metal from contacting components, such as a tip or nozzle, of the plasma arc torch. The shield cap may comprise a mechanized cap, a drag cap, a gouging cap, or a deflector cap, among others. Accordingly, various shield caps may be employed without removal or replacement of the vented retainer. The same vented retainer may be used throughout a variety of plasma arc torch applications.

Claims

1. A vented shield system for use in a plasma arc torch comprising:

a shield cup body defining a distal end portion;

a vented retainer secured to the distal end portion of the shield cup body, the vented retainer defining at least one vent passageway; and

a shield cap secured to the vented retainer, the shield cap defining a central exit orifice,

wherein the vent passageway directs a flow of vent gas inward toward the shield cap, a plasma stream and a secondary gas exit the central exit orifice in the shield cap, and the vented shield system blocks at least a portion of molten metal from contacting components of the plasma arc torch.

2. The vented shield system according to claim 1, wherein the shield cap is a mechanized cap.

3. The vented shield system according to claim 2, wherein:

the vented retainer comprises a proximal end portion secured to the distal end portion of the shield cup body and a distal face having a central opening, and a plurality of vent passageways formed through the distal face; and

the mechanized cap comprises a proximal end portion secured within the central opening of the vented retainer and a distal face defining a central exit orifice,

wherein the vent passageways direct a flow of vent gas inward toward the mechanized cap for cooling, a plasma stream and a secondary gas exit the central exit orifice in the mechanized cap, and the mechanized cap blocks molten metal from contacting components of the plasma arc torch during operation.

4. The vented shield system according to claim 1, wherein the shield cap is a drag cap.

5. The vented shield system according to claim 4, wherein:

the vented retainer comprises a proximal end portion secured to the distal end portion of the shield cup body and a distal face having a central opening and a plurality of vent passageways formed through the distal face; and

the drag cap comprises a proximal end portion secured within the central opening of the vented retainer and a distal face defining a central exit orifice and a plurality of channels,

wherein the vent passageways direct a flow of vent gas inward toward the drag cap for cooling, a plasma stream and a secondary gas exit the central exit orifice in the drag cap, the channels vent a portion of the secondary gas away from the plasma stream, and the drag cap blocks molten metal from contacting components of the plasma arc torch during operation.

6. The vented shield system according to claim 1, wherein the shield cap is a gouging cap.

7. The vented shield system according to claim 6, wherein:

the vented retainer comprises a proximal end portion secured to the distal end portion of the shield cup body and a distal face having a central opening and a plurality of vent passageways formed through the distal face; and

the gouging cap comprises a proximal end portion secured within the central opening of the vented retainer, an annular external flange disposed around the proximal end portion, and a central exit orifice,

wherein the annular external flange abuts the distal face of the vented retainer to block the vent passageways and a plasma stream and a secondary gas exit the central exit orifice during gouging operations of the plasma arc torch.

8. The vented shield system according to claim 1, wherein the shield cap is a deflector cap.

9. The vented shield system according to claim 8, wherein:

the vented retainer comprises a proximal end portion secured to the distal end portion of the shield cup body and a distal face having a central opening and a plurality of vent passageways formed through the distal face; and

the deflector cap comprises a proximal end portion secured within the central opening of the vented retainer, an annular external flange disposed around a distal end portion of the deflector cap, and a central exit orifice,

wherein the annular external flange abuts the distal face of the vented retainer to block the vent passageways and a plasma stream and a secondary gas exit the central exit orifice during operation of the plasma arc torch.

10. The vented shield system according to claim 1, wherein the vent passageways are canted.

11. A vented shield system for use in a plasma arc torch comprising:

a shield cup body defining a distal end portion;

a vented retainer comprising;

a proximal end portion secured to the distal end portion of the shield cup body; and

a distal face having a central opening and a plurality of vent passageways formed through the distal face; and

a mechanized cap comprising;

a proximal end portion secured within the central opening of the vented retainer; and

a distal face defining a central exit orifice,

wherein the vent passageways direct a flow of vent gas inward toward the mechanized cap for cooling, a plasma stream and a secondary gas exit the central exit orifice in the mechanized cap, and the mechanized cap blocks molten metal from contacting components of the plasma arc torch during operation of the plasma arc torch.

12. A vented shield system for use in a plasma arc torch comprising:

a shield cup body defining a distal end portion;

a vented retainer comprising;

a proximal end portion secured to the distal end portion of the shield cup body; and

a distal face having a central opening and a plurality of vent passageways formed through the distal face; and

a drag cap comprising;

a proximal end portion secured within the central opening of the vented retainer; and

a distal face defining a central exit orifice and a plurality of channels,

wherein the vent passageways direct a flow of vent gas inward toward the drag cap for cooling, a plasma stream and a secondary gas exit the central exit orifice in the drag cap, the channels vent a portion of the secondary gas away from the plasma stream, and the drag cap blocks molten metal from contacting components of the plasma arc torch during operation.

13. A vented shield system for use in a plasma arc torch comprising:

a shield cup body defining a distal end portion;

a vented retainer comprising;

a proximal end portion secured to the distal end portion of the shield cup body; and

a distal face having a central opening and a plurality of vent passageways formed through the distal face; and

a gouging cap comprising;

a proximal end portion secured within the central opening of the vented retainer;

an annular external flange disposed around the proximal end portion; and

a central exit orifice,

wherein the annular external flange abuts the distal face of the vented retainer to block the vent passageways and a plasma stream and a secondary gas exit the central exit orifice in the gouging cap during gouging operations of the plasma arc torch.

14. A vented shield system for use in a plasma arc torch comprising:

a shield cup body defining a distal end portion;

a vented retainer comprising;

a proximal end portion secured to the distal end portion of the shield cup body; and

a distal face having a central opening and a plurality of vent passageways formed through the distal face; and

a deflector cap comprising;

a proximal end portion secured within the central opening of the vented retainer;

an annular external flange disposed around a distal end portion of the deflector cap; and

a central exit orifice,

wherein the annular external flange abuts the distal face of the vented retainer to block the vent passageways and a plasma stream and a secondary gas exit the central exit orifice in the deflector cap during operation of the plasma arc torch.

15. A vented retainer for use in retaining a variety of shield caps of a plasma arc torch, the vented retainer comprising:

a body defining a proximal end portion and a distal end portion;

a distal face formed at the distal end portion;

an opening formed through the distal face;

an attachment area disposed proximate the opening; and

at least one vent passageway formed through the distal face, the vent passageway being angled inward,

wherein a shield cap is secured to the vented retainer through the attachment area and the vent passageway direct a flow of vent gas inward toward the shield cap.

16. The vented retainer according to claim 15 comprising a plurality of vent passageways spaced evenly around the distal face.

17. The vented retainer according to claim 15, wherein the vent passageway is canted.

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

a proximal end portion defining an external attachment area; and

a central exit orifice disposed distally from the external attachment area,

wherein the external attachment area is adapted for engagement with an adjacent attachment area of the plasma arc torch.

19. The shield cap according to claim 18, wherein the external attachment area defines threads.

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

a proximal end portion defining an external annular flange; and

a central exit orifice disposed distally from the external annular flange,

wherein the external annular flange is adapted to engage an adjacent component of the plasma arc torch to redirect a flow of a vent gas.

22. The plasma arc torch according to claim 20, wherein the shield cap is a mechanized cap.

23. The plasma arc torch according to claim 22, wherein:

the vented retainer comprises a proximal end portion secured to the distal end portion of the shield cup body and a distal face having a central opening, and a plurality of vent passageways formed through the distal face; and

the mechanized cap comprises a proximal end portion secured within the central opening of the vented retainer and a distal face defining a central exit orifice,

wherein the vent passageways direct a flow of vent gas inward toward the mechanized cap for cooling, a plasma stream and a secondary gas exit the central exit orifice in the mechanized cap, and the mechanized cap blocks molten metal from contacting the tip and other components of the plasma arc torch during operation.

21. A plasma arc torch comprising:

a vented shield system comprising;

a shield cup body defining a distal end portion;

a vented retainer secured to the distal end portion of the shield cup body, the vented retainer defining at least one vent passageway; and

a shield cap secured to the vented retainer, the shield cap defining a central exit orifice; and

a tip disposed at a distal end portion of the plasma arc torch and positioned at least partially within the vented shield system,

wherein the vent passageway directs a flow of vent gas inward toward the shield cap, a plasma stream and a secondary gas exit the central exit orifice in the shield cap, and the vented shield system blocks at least a portion of molten metal from contacting the tip and other components of the plasma arc torch during operation.

24. The plasma arc torch according to claim 21, wherein the shield cap is a drag cap.

25. The plasma arc torch according to claim 24, wherein:

the vented retainer comprises a proximal end portion secured to the distal end portion of the shield cup body and a distal face having a central opening and a plurality of vent passageways formed through the distal face; and

the drag cap comprises a proximal end portion secured within the central opening of the vented retainer and a distal face defining a central exit orifice and a plurality of channels,

wherein the vent passageways direct a flow of vent gas inward toward the drag cap for cooling, a plasma stream and a secondary gas exit the central exit orifice in the drag cap, the channels vent a portion of the secondary gas away from the plasma stream, and the drag cap blocks molten metal from contacting components of the plasma arc torch during operation.

26. The plasma arc torch according to claim 21, wherein the shield cap is a gouging cap.

27. The plasma arc torch according to claim 26, wherein:

the vented retainer comprises a proximal end portion secured to the distal end portion of the shield cup body and a distal face having a central opening and a plurality of vent passageways formed through the distal face; and

the gouging cap comprises a proximal end portion secured within the central opening of the vented retainer, an annular external flange disposed around the proximal end portion, and a central exit orifice,

wherein the annular external flange abuts the distal face of the vented retainer to block the vent passageways, a plasma stream and a secondary gas exit the central exit orifice in the gouging cap, and the gouging cap blocks molten metal from contacting at least a portion of the tip and other components of the plasma arc torch during operation.

28. The plasma arc torch according to claim 21, wherein the shield cap is a deflector cap.

29. The plasma arc torch according to claim 28, wherein:

the vented retainer comprises a proximal end portion secured to the distal end portion of the shield cup body and a distal face having a central opening and a plurality of vent passageways formed through the distal face; and

the deflector cap comprises a proximal end portion secured within the central opening of the vented retainer, an annular external flange disposed around a distal end portion of the deflector cap, and a central exit orifice,

wherein the annular external flange abuts the distal face of the vented retainer to block the vent passageways, a plasma stream and a secondary gas exit the central exit orifice in the deflector cap, and the tip extends partially through the central exit orifice of the deflector cap.

30. The plasma arc torch according to claim 21, wherein:

the shield cap defines an internal face;

the central exit orifice defines a diameter; and

the tip defines a distal face, the distance between the internal face and the distal face defining a spacing,

wherein the spacing is approximately 0.040 inches and the diameter is approximately 0.120 when the plasma arc torch is operating at approximately 80 amps.

31. The plasma arc torch according to claim 21, wherein:

the shield cap defines an internal face;

the central exit orifice defines a diameter; and

the tip defines a distal face, the distance between the internal face and the distal face defining a spacing,

wherein the spacing is approximately 0.016 inches and the diameter is approximately 0.100 when the plasma arc torch is operating at approximately 50 amps.

32. The plasma arc torch according to claim 21, wherein:

the shield cap defines an internal face;

the central exit orifice defines a diameter; and

the tip defines a distal face, the distance between the internal face and the distal face defining a spacing,

wherein the spacing is approximately 0.016 inches and the diameter is approximately 0.064 when the plasma arc torch is operating at approximately 40 amps.

33. The plasma arc torch according to claim 21, wherein the vent passageways are canted.

34. A vented shield system for use in a plasma arc torch comprising:

a shield cup body defining a distal end portion;

a vented retainer secured to the distal end portion of the shield cup body; and

a shield cap secured to the vented retainer; and

a means for venting a vent gas inward toward the shield cap; and

a means for blocking at least a portion of a molten metal from contacting components of the plasma arc torch during operation.

35. A method of operating a plasma arc torch, the method comprising the steps of:

(a) directing a flow of vent gas inward, through a first component of the plasma arc torch and toward a second component of the plasma arc torch; and

(b) blocking at least a portion of molten metal from contacting components of the plasma arc torch using at least the second component.

36. The method according to claim 35 further comprising the step of directing a portion of a secondary gas away from a plasma stream using the second component.

37. A method of operating a vented shield system on a plasma arc torch in a variety of operating modes comprising mechanized, drag, gouging, and deflecting, the vented shield system comprising at least one vent passageway to direct a flow of vent gas, the method comprising the step of interchanging a plurality of shield caps that correspond to the operating modes without removing the vent passageway.