Nozzle head with increased shoulder thickness
View Patent ↗A consumable for a plasma arc torch, such as a nozzle, having a body and a head defining a shoulder portion having a frusto-conical portion and a flared portion. The flared portion increases the cross-sectional thickness to provide a greater heat-conduction path for removal of heat generated by a plasma arc, thereby extending consumable life. The frusto-conical portion provides a sharper, pointier nozzle head to simultaneously increase the operator's visibility of the workpiece. Methods of making and using the consumables are also included.
1. A nozzle for a gas-cooled plasma arc cutting torch, the nozzle comprising:
a body comprising a hollow interior having a cylindrical portion that defines a central longitudinal axis and an inside diameter; and
a nozzle head defining:
a plasma exit orifice disposed about the central longitudinal axis;
a shoulder portion comprising a generally non-cylindrical portion and a second portion that, in combination, define an external contoured surface, the second portion disposed between the generally non-cylindrical portion and the body, and
a region of a minimum cross-sectional thickness between the generally non-cylindrical portion and the second portion.
2. The nozzle of claim 1 , wherein a contour line defined by the external contoured surface correlates to the region of the minimum cross-sectional thickness.
3. The nozzle of claim 2 , wherein the second portion is disposed between the contour line and a second region on the body that correlates to the intersection of the body and the shoulder portion.
4. The nozzle of claim 2 , wherein the contour line is disposed between the generally non-cylindrical portion and the second portion.
5. The nozzle of claim 1 , wherein the generally non-cylindrical portion is disposed nearer the longitudinal axis than is the inside diameter of the body.
6. The nozzle of claim 1 , wherein substantially all of the generally non-cylindrical portion is between an end face of the nozzle head and a point on the nozzle body that corresponds to an insert depth of the electrode.
7. The nozzle of claim 1 , wherein substantially all of the generally non-cylindrical portion is between an end face of the nozzle head and a bottom interior surface of the nozzle head.
8. The nozzle of claim 2 , wherein a second angle measured between the longitudinal axis and a second tangent line to a second exterior surface of the second portion is greater than a first angle measured between the longitudinal axis and a first tangent line to a first exterior surface of the generally non-cylindrical portion.
9. The nozzle of claim 8 , wherein the second portion is disposed between the generally non-cylindrical portion and a reference point located by extending the first tangent line to an exterior surface of the nozzle body.
10. The nozzle of claim 8 , wherein the second tangent line passes through the second portion at a point of the nozzle head furthest from the longitudinal axis.
11. The nozzle of claim 8 , wherein the second angle is approximately 90 degrees.
12. The nozzle of claim 1 , wherein the region of minimum cross-sectional thickness corresponds to a heat transfer density proportionate to not more than about 2 amperes of torch operating current per square millimeter of nozzle cross-sectional conduction area at the region of minimum thickness.
13. The nozzle of claim 1 , wherein the generally non-cylindrical portion is at least substantially conical.
14. The nozzle of claim 1 , wherein the second portion is at least substantially conical.
15. The nozzle of claim 1 , wherein the external contoured surface of the shoulder portion defines at least one of a nonlinear or irregular surface.
16. The nozzle of claim 2 , wherein the contour line is between the generally non-cylindrical portion and a point on the nozzle body that corresponds to an insert depth of the electrode.
17. The nozzle of claim 2 , wherein the contour line is disposed between the generally non-cylindrical portion and a bottom interior surface of the nozzle head.
18. The nozzle of claim 1 , wherein the generally non-cylindrical portion and the second portion are at least substantially contiguous.
19. The nozzle of claim 8 , wherein the second tangent line substantially parallels the second exterior surface.
20. The nozzle of claim 8 , wherein the first tangent line substantially parallels the first exterior surface.
21. A nozzle for a gas-cooled plasma arc cutting torch, the nozzle comprising:
a body comprising a hollow interior having a cylindrical portion that defines a central longitudinal axis, an inside diameter, and an external body surface; and
a nozzle head defining:
a plasma exit orifice disposed about the central longitudinal axis;
a shoulder portion defining an external contoured surface, wherein the shoulder portion has a first section and a second section disposed within a cross section of the shoulder portion that passes through the central longitudinal axis, the first section having a first external contour disposed between an end face of the nozzle head and an external surface of the nozzle body, the second section having a second external contour disposed between the external surface of the nozzle body and the first external contour, such that an angle φ 1 measured between the central longitudinal axis and a first tangent line to a first point on the first external contour is less than an angle φ 2 measured between the central longitudinal axis and a second tangent line to a second point on the second shoulder contour; and
a region of a minimum cross-sectional thickness between the first external contour and the second external contour.
22. The nozzle of claim 21 , wherein a contour point correlates to the region of the minimum cross-sectional thickness.
23. The nozzle of claim 22 , wherein the contour point is disposed between the first external contour and a second region on the body that correlates to the intersection of the body and the shoulder portion.
24. The nozzle of claim 21 , wherein the external contoured surface of the shoulder defines a nonlinear or irregular surface.
25. The nozzle of claim 21 , wherein the second tangent line passes through the second section at a point of the nozzle head furthest from the longitudinal axis.
26. The nozzle of claim 21 , wherein φ 2 is approximately 90 degrees.
27. The nozzle of claim 21 , wherein the first and second sections of the shoulder are at least substantially conical.
28. The nozzle of claim 21 , wherein the first and second sections are at least substantially contiguous.
29. The nozzle of claim 21 , wherein the first tangent line substantially parallels the first external contour.
30. The nozzle of claim 21 , wherein the second tangent line substantially parallels the second external contour.
31. A nozzle for a gas-cooled plasma arc cutting torch, the nozzle comprising:
a body comprising a hollow interior having a cylindrical portion that defines a central longitudinal axis and an inside diameter; and
a nozzle head defining:
a plasma exit orifice disposed about the central longitudinal axis;
a shoulder portion between an end face of the nozzle head and the body, the shoulder portion comprising an at least substantially frusto-conical portion and a flared portion that, in combination, define an external contoured surface of the shoulder portion, at least a portion of the frusto-conical portion disposed between an end face of the nozzle head and the flared portion, the flared portion disposed between the nozzle body and the frusto-conical portion; and
a region of minimum cross-sectional thickness disposed within the flared portion.
32. The nozzle of claim 31 further comprising a contour line disposed on the external contoured surface that identifies the region of the minimum cross-sectional thickness.
33. The nozzle of claim 32 , wherein the contour line is disposed at the intersection of the frusto-conical portion and the flared portion.
34. The nozzle of claim 32 , wherein the contour line is disposed between the end face of the nozzle head and a point on the nozzle body that corresponds to an insert depth of the electrode.
35. The nozzle of claim 31 , wherein an exterior surface of the flared portion forms a substantial portion of the external contoured surface.
36. The nozzle of claim 31 , wherein the external contoured surface of the shoulder portion includes at least one of an irregular or non-linear cross-sectional shape.
37. The nozzle of claim 32 , wherein a second angle measured between the central longitudinal axis and a second tangent line to an outermost exterior surface of the nozzle head is greater than a first angle measured between the central longitudinal axis and a first tangent line to a point on the shoulder that corresponds to the contour line.
38. The nozzle of claim 32 , wherein the region of minimum cross-sectional thickness corresponds to a heat transfer density proportionate to not more than about 2 amperes of torch operating current per square millimeter of nozzle cross-sectional conduction area at the region of minimum cross-sectional thickness.
39. The nozzle of claim 37 , wherein the contour line is disposed nearer the longitudinal axis than is the inside diameter of the body.
40. The nozzle of claim 37 , wherein the second angle is approximately 90 degrees.
41. The nozzle of claim 31 , wherein the flared portion is at least substantially conical.
42. The nozzle of claim 37 , wherein the second tangent line substantially parallels the outermost exterior surface of the nozzle head.
43. The nozzle of claim 37 , wherein the first tangent line substantially parallels a first exterior surface of the shoulder.
44. A torch tip comprising:
a nozzle comprising:
a nozzle body comprising a hollow interior having a cylindrical portion that defines a central longitudinal axis and an inside diameter; and
a nozzle head defining:
a plasma exit orifice disposed about the central longitudinal axis; and
a nozzle shoulder portion comprising a first generally non-cylindrical portion and a second nozzle portion that, in combination, define an external contoured surface, the second nozzle portion disposed between the first generally non-cylindrical shoulder portion and the nozzle body;
a region of minimum cross-sectional thickness between the first generally non-cylindrical portion and the second nozzle portion; and
a shield comprising:
a shield body including a fastener for securing the shield to the torch body in a spaced relationship relative to the nozzle, for routing a shield gas through a space between the shield body and the nozzle; and
a shield head defining:
a shield exit orifice disposed about the central longitudinal axis; and
a shield shoulder portion comprising a second generally non-cylindrical portion and a second shield portion that, in combination, define an internal contoured surface, the second shield portion disposed between the second generally non-cylindrical portion and the body, the second generally non-cylindrical and second shield portions corresponding to the first generally non-cylindrical and second nozzle portions.
45. The torch tip of claim 44 , wherein a second angle measured between the longitudinal axis and a second tangent line to a second external surface of the second nozzle portion is greater than a first angle measured between the longitudinal axis and a first tangent line to a first external surface of the first generally non-cylindrical portion.
46. The torch tip of claim 44 , wherein the second angle is approximately 90 degrees.
47. The torch tip of claim 45 , wherein the first generally non-cylindrical portion and the second nozzle portion are substantially conical.
48. The torch tip of claim 44 , wherein the generally non-cylindrical portion and the second nozzle portion are at least substantially contiguous.
49. The torch tip of claim 45 , wherein the second tangent line at least substantially parallels the second external surface.
50. The torch tip of claim 45 , wherein the first tangent line at least substantially parallels the first external surface.
51. A gas-cooled plasma arc torch comprising the torch tip of claim 44 .
52. A method for increasing the life of a nozzle, the method comprising:
providing a nozzle having a body and a nozzle head, the nozzle head defining an at least substantially frusto-conical shoulder portion such that a first nozzle wear rate results; and
defining the nozzle of claim 1 further comprising a flared shoulder portion that, in combination with the at least substantially frusto-conical shoulder portion, defines a nozzle shoulder defining the external contoured surface, at least a portion of the frusto-conical surface disposed between an end face of the nozzle head and the flared portion, the flared portion disposed between the body and the frusto-conical portion, such that a second nozzle wear rate results, the second nozzle wear rate less than the first nozzle wear rate.
53. The method of claim 52 , further comprising the step of:
forming the flared shoulder portion such that a second angle measured between the central longitudinal axis and a second tangent line to an outermost exterior surface of the nozzle head is greater than a first angle measured between the central longitudinal axis and a first tangent line to a point on the shoulder that corresponds to the contour line.
54. The torch tip of claim 52 , further comprising the step of:
establishing a contour line on the contoured surface that correlates to the region of the minimum shoulder thickness between the generally non-cylindrical portion and the second portion.
55. The method of claim 53 , further comprising the step of:
defining the second angle to be approximately 90 degrees.
56. The method of claim 54 , further comprising the step of:
positioning the contour line to be at the intersection of the frusto-conical portion and the flared portion.
57. The method of claim 54 , further comprising the step of:
disposing the contour line nearer the longitudinal axis than an inside diameter of the body.
58. The method of claim 52 , further comprising the step of:
defining the external contoured surface with an irregular or non-linear cross-sectional shape.
59. The method of claim 52 , further comprising the step of:
defining the flared portion as substantially conical.
60. The method of claim 58 , further comprising the step of:
establishing the region of minimum shoulder thickness to with at least a minimum thickness to correspond to a heat transfer density proportionate to not more than about 2 amperes of torch operating current per square millimeter of nozzle cross-sectional conduction area at the region of minimum shoulder thickness.