Title: Plasma arc torch electrode
Abstract: A variety of electrodes for use in a plasma arc torch are provided that improve cooling between the electrode and an adjacent cathodic element such as a cathode. At least one passageway is formed between the electrode and the cathode for the flow of a fluid, e.g. cooling fluid, wherein the flow of the fluid is proximate, or through an adjacent vicinity of, electrical contact between the cathode and the electrode. The passageway is formed through the electrode, through the cathode, between the electrode and the cathode, and through a third element in the various forms of the present invention. Further, methods of operating a plasma arc torch using the electrodes according to the various forms of the invention are also provided.
Patent Number: 6,998,566 Issued on 02/14/2006 to Conway, et al.
| Inventors:
|
Conway; Christopher J. (Wilmot, NH);
Kinerson; Kevin J. (Corinth, VT);
Gugliotta; Mark (Concord, NH);
MacKenzie; Darrin H. (Windsor, VT)
|
| Assignee:
|
Thermal Dynamics Corporation (West Lebanon, NH)
|
| Appl. No.:
|
409633 |
| Filed:
|
April 7, 2003 |
| Current U.S. Class: |
219/121.52; 219/121.49; 219/121.48; 219/75 |
| Current Intern'l Class: |
B23K 10/00 (20060101) |
| Field of Search: |
219/12149,121.36,121.5,74,75,121.48,121.52
313/231.31,231.41
315/111.21,111.41,111.51
|
References Cited [Referenced By]
U.S. Patent Documents
| 3740522 | Jun., 1973 | Muehlberger.
| |
| 3858072 | Dec., 1974 | Dembovsky.
| |
| 4140892 | Feb., 1979 | Muller.
| |
| 4311897 | Jan., 1982 | Yerushalmy.
| |
| 4521666 | Jun., 1985 | Severance, Jr. et al.
| |
| 5416296 | May., 1995 | Walters.
| |
| 5726415 | Mar., 1998 | Luo et al.
| |
| 5965040 | Oct., 1999 | Luo et al.
| |
| 6114650 | Sep., 2000 | Marner et al.
| |
| 6163008 | Dec., 2000 | Roberts et al.
| |
| 6346685 | Feb., 2002 | Severance, Jr. et al.
| |
| 6403915 | Jun., 2002 | Cook et al.
| |
| 2003/0034333 | Feb., 2003 | Horner-Richardson et al.
| |
Primary Examiner: Paschall; Mark
Attorney, Agent or Firm: Harness, Dickey & Pierce, P.L.C.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon Provisional Patent Application Ser. No. 60/373,992
entitled "Plasma Arc Torch" filed 19 Apr. 2002, the contents of which are incorporated
herein by reference in their entirety and continued preservation of which is requested.
Claims
What is claimed is:
1. A plasma arc torch comprising:
a cathodic element defining a perimeter surface; and
an electrode configured for electrical contact with the cathodic element and
passage of a fluid between the cathodic element and the electrode, the electrode
defining a perimeter surface adjacent the perimeter surface of the cathodic element,
wherein the adjacent perimeter surfaces provide the electrical contact and the
passage of the fluid.
2. The plasma arc torch according to claim 1 wherein the electrode further comprises
at least one passageway configured for passage of the cooling fluid proximate the
electrical contact.
3. The plasma arc torch according to claim 2 wherein the passageway further comprises
at least one flute formed on the electrode.
4. The plasma arc torch according to claim 2 wherein the passageway further comprises
at least one helical flute formed on the electrode.
5. The plasma arc torch according to claim 1 wherein the electrode further comprises
at least one rib and at least one flute disposed adjacent the at least one rib,
the rib and the flute disposed along the perimeter surface of the electrode.
6. The plasma arc torch according to claim 5 wherein the electrode further comprises
a plurality of ribs disposed adjacent a plurality of flutes, the ribs and the flutes
disposed along the perimeter surface of the electrode.
7. The plasma arc torch according to claim 1 wherein the electrode further comprises
a detent for connection to an adjacent component of the plasma arc torch.
8. The plasma arc torch according to claim 1 further comprising a third element
disposed between electrode and the cathodic element for the electrical contact
and the passage of the fluid.
9. The plasma arc torch according to claim 8 wherein the third element is a porous
and conductive material.
10. The plasma arc torch according to claim 8 wherein the third element is a
canted coil spring.
11. The plasma arc torch according to claim 1 wherein the electrode further comprises
at least one spot recess disposed proximate the electrical contact for passage
of the fluid.
12. The plasma arc torch according to claim 1 wherein the cathodic element comprises
at least one spot recess disposed proximate the electrical contact for passage
of the fluid.
13. The plasma arc torch according to claim 1 wherein the cathodic element comprises
at least one passageway configured for passage of the fluid.
14. The plasma arc torch according to claim 1 wherein the cathodic element comprises
at least one rib.
15. The plasma arc torch according to claim 14 wherein a rib comprises at least
one internal passageway.
16. The plasma arc torch according to claim 1 wherein the cathodic element comprises
at least one flute.
17. The plasma arc torch according to claim 1 wherein the cathodic element comprises
at least one flute disposed adjacent at least one rib.
18. The plasma arc torch according to claim 1 wherein the cathodic element is
composed of a porous material.
19. The plasma arc torch according to claim 1 wherein the fluid is a cooling fluid.
20. A plasma arc torch comprising:
a cathodic element; and
an electrode configured for electrical contact with the cathodic element,
wherein a cooling fluid passes through at least one passageway through an adjacent
vicinity of the electrical contact between the cathodic element and the electrode.
21. The plasma arc torch according to claim 20 wherein the cathodic element comprises
at least one passageway configured for passage of the cooling fluid.
22. The plasma arc torch according to claim 20 wherein the electrode comprises
at least one passageway configured for passage of the cooling fluid.
23. The plasma arc torch according to claim 20 wherein the electrode further
comprises at least one axial passage disposed along the electrode.
24. The plasma arc torch according to claim 23 wherein the electrode further
comprises a plurality of proximal axial slots defining proximal contact pads and
radial passages formed distally from the axial slots, the proximal contact pads
providing the electrical contact and the axial slots and radial passages providing
for passage of the cooling fluid.
25. The plasma arc torch according to claim 23 wherein the passageway further
comprises at least one internal undercut.
26. The plasma arc torch according to claim 23 wherein the passageway further
comprises at least one external undercut.
27. A plasma arc torch comprising:
a cathodic element;
an electrode configured for electrical contact with the cathodic element and
passage of a fluid between the cathodic element and the electrode, the electrode
comprising at least one rib and at least one flute disposed adjacent the at least
one rib,
wherein the rib contacts the cathodic element for electrical contact and the
fluid passes through the flute for cooling proximate the electrical contact.
28. The plasma arc torch according to claim 27 wherein the electrode further
comprises a detent for connection to an adjacent component of the plasma arc torch.
29. The plasma arc torch according to claim 27 wherein the electrode comprises
a plurality of ribs and flutes.
30. A plasma arc torch comprising:
a cathodic element;
an electrode configured for electrical contact with the cathodic element and
passage of a fluid between the cathodic element and the electrode, the electrode
comprising a plurality of ribs and a plurality of flutes disposed between the ribs,
wherein the ribs contact the cathodic element for the electrical contact and
the fluid passes through the flutes for the passage of fluid proximate the electrical contact.
31. An electrode configured for electrical contact and passage of a fluid between
the electrode and an adjacent cathodic element of a plasma arc torch, the electrode
comprising a perimeter surface adjacent a perimeter surface of the cathodic element,
wherein the adjacent perimeter surfaces provide the electrical contact and the
passage of the fluid.
32. The electrode according to claim 31 wherein the electrode further comprises
at least one passageway configured for passage of the cooling fluid proximate the
electrical contact.
33. The electrode according to claim 32 wherein the passageway further comprises
at least one flute formed on the electrode.
34. The electrode according to claim 33 wherein the passageway further comprises
at least one helical flute formed on the electrode.
35. The electrode according to claim 31 wherein the electrode further comprises
at least one rib and at least one flute disposed adjacent the at least one rib,
the rib and the flute disposed along the perimeter surface of the electrode.
36. The electrode according to claim 31 wherein the electrode further comprises
a plurality of ribs disposed adjacent a plurality of flutes, the ribs and the flutes
disposed along the perimeter surface of the electrode.
37. The electrode according to claim 31 wherein the electrode further comprises
a detent for connection to an adjacent component of the plasma arc torch.
38. The electrode according to claim 31 wherein the electrode further comprises
at least one spot recess disposed proximate the electrical contact for passage
of the fluid.
39. An electrode configured for electrical contact with a cathodic element of
a plasma arc torch, the electrode comprising at least one passageway and a perimeter
surface adjacent a perimeter surface of the cathodic element,
wherein a cooling fluid passes through the passageway for cooling proximate the
electrical contact and the adjacent perimeter surfaces provide the electrical contact.
40. An electrode configured for electrical contact with a cathodic element of
a plasma arc torch and passage of a fluid between the cathodic element and the
electrode, the electrode comprising at least one rib and at least one flute disposed
adjacent the at least one rib,
wherein the rib contacts the cathodic element for electrical contact and the
fluid passes through the flute for cooling proximate the electrical contact.
41. The electrode according to claim 40 wherein the electrode further comprises
a detent for connection to an adjacent component of the plasma arc torch.
42. The electrode according to claim 40 wherein the electrode comprises a plurality
of ribs and flutes.
43. An electrode configured for electrical contact with a cathodic element of
a plasma arc torch and passage of a cooling fluid for cooling proximate the electrical
contact, the electrode comprising:
a plurality of ribs; and
a plurality of flutes disposed between the ribs,
wherein the ribs contact an adjacent cathodic element for the electrical contact
and the fluid passes through the flutes for the passage of fluid proximate the
electrical contact.
44. The electrode according to claim 43 wherein the electrode further comprises
a detent for connection to an adjacent component of the plasma arc torch.
45. An electrode configured for electrical contact with a cathodic element of
a liquid cooled plasma arc torch and passage of a cooling fluid, the electrode comprising:
a distal end portion;
a hafnium insert disposed within the distal end portion; and
at least one fluid passageway formed through the distal end portion and proximate
the hafnium insert,
wherein the cooling fluid flows through the fluid passageway to cool the electrode.
46. A plasma arc torch comprising:
a cathodic element;
an electrode holder disposed at a distal end portion of the cathodic element,
the electrode holder in electrical contact with the cathodic element; and
an electrode configured for electrical contact with the electrode holder,
wherein a cooling fluid passes through the electrode holder and along an adjacent
vicinity of the electrical contact between the electrode holder and the electrode.
47. A plasma arc torch comprising:
a cathodic element defining a distal end face; and
an electrode disposed adjacent the cathodic element and defining a proximal end face,
wherein the proximal end face of the electrode abuts the distal end face of the
cathodic element for electrical contact and a cooling fluid flows along an adjacent
vicinity of the electrical contact.
48. A plasma arc torch comprising:
a means for conducting electric power between an electrode and an adjacent cathodic
element; and
a means for conducting fluid between the electrode and the adjacent cathodic
element proximate the conducting electric power.
49. An electrode for use in a plasma arc torch comprising:
a means for conducting electric power between the electrode and an adjacent cathodic
element; and
a means for conducting fluid between the electrode and the adjacent cathodic
element proximate the conducting electric power.
50. A method of operating a plasma arc torch, the method comprising the step of:
conducting a cooling fluid and electric power between adjacent perimeter surfaces
of an electrode and an adjacent cathodic element,
wherein the adjacent perimeter surfaces provide the electrical contact and the
passage of the fluid.
51. A method of operating a plasma arc torch, the method comprising the steps of:
conducting a cooling fluid through at least one passageway defined along an electrode; and
conducting electric power along adjacent perimeter surfaces of the electrode
and an adjacent cathodic element,
wherein the cooling fluid passes through the passageway for cooling proximate
the electrical contact and the adjacent perimeter surfaces provide the electrical contact.
52. A method of operating a plasma arc torch, the method comprising the steps of:
conducting a cooling fluid through at least one flute defined along an electrode
proximate an electrical connection between the electrode and an adjacent cathodic
element; and
conducting electric power through at least one rib disposed between the plurality
of flutes.
53. A method of operating a plasma arc torch, the method comprising the steps of:
conducting a cooling fluid through a plurality of flutes defined along an electrode
proximate an electrical connection between the electrode and an adjacent cathodic
element; and
conducting electric power through a plurality of ribs disposed between the plurality
of flutes, wherein the ribs are in electrical contact with the cathodic element.
Description
FIELD OF THE INVENTION
The present invention relates generally to plasma arc torches and more particularly
to electrodes and methods of use for automated, high current plasma arc torches.
BACKGROUND OF THE INVENTION
Plasma arc torches, also known as electric arc torches, are commonly used
for cutting, marking, gouging, and welding metal workpieces by directing a high
energy plasma stream consisting of ionized gas particles toward the workpiece.
In a typical plasma arc torch, the gas to be ionized is supplied to a distal end
of the torch and flows past an electrode before exiting through an orifice in the
tip, or nozzle, of the plasma arc torch. The electrode has a relatively negative
potential and operates as a cathode. Conversely, the torch tip constitutes a relatively
positive potential and operates as an anode. Further, the electrode is in a spaced
relationship with the tip, thereby creating a gap, at the distal end of the torch.
In operation, a pilot arc is created in the gap between the electrode and the tip,
which heats and subsequently ionizes the gas. Further, the ionized gas is blown
out of the torch and appears as a plasma stream that extends distally off the tip.
As the distal end of the torch is moved to a position close to the workpiece, the
arc jumps or transfers from the torch tip to the workpiece because the impedance
of the workpiece to ground is lower than the impedance of the torch tip to ground.
Accordingly, the workpiece serves as the anode, and the plasma arc torch is operated
in a "transferred arc" mode.
In automated plasma arc torch applications, the plasma arc torch operates at
current
levels between approximately 30 amps and 1,000 amps or more. At the higher current
levels, the torch correspondingly operates at relatively high temperatures. Accordingly,
torch components and consumable components must be properly cooled in order to
prevent damage or malfunction and to increase the operating life and cutting accuracy
of the plasma arc torch. To provide such cooling, high current plasma arc torches
are generally water cooled, although additional cooling fluids may be employed,
wherein coolant supply and return tubes are provided to cycle the flow of cooling
fluid through the torch. Additionally, a variety of cooling and gas passageways
are provided throughout various torch components for proper operation of the plasma
arc torch. However, the flow of cooling fluids in plasma arc torches of the known
art have been relatively limited due to the positioning and configuration of internal
cooling passageways.
With automated plasma arc torches of the known art, concentricity of components
within the torch, such as the electrode and the tip, or nozzle, is critical in
order to maintain accuracy when cutting a workpiece. Further, the electrode and
the tip are commonly known as consumable components, which must replaced after
a certain period of operation due to wear and/or damage that occurs during operation.
Accordingly, concentricity of such consumable components must be maintained throughout
the many replacements that occur over the life of a plasma arc torch.
Additionally, when the consumable components are replaced, tools are
often required for removal due to the type of connection between the consumable
components and a torch head. For example, the consumable components may be threaded
into the torch head and tightened with a wrench or other tool. As a result, the
replacement of consumable components is often time consuming and cumbersome for
a plasma arc torch operator. Moreover, each of the consumable components are typically
replaced on an individual basis, rather than all at once, thereby making removal
and installation of several different consumable components at different even more
time consuming and cumbersome.
Accordingly, a need remains in the art for a plasma arc torch and associated
methods that improve cutting efficiency and accuracy. A further need exists for
such a plasma arc torch and methods that provide for relatively quick and efficient
replacement of consumable components, (e.g., electrode, tip), disposed therein.
SUMMARY OF THE INVENTION
Generally, the present invention provides a plasma arc torch that comprises
a set of torch consumable components secured to a torch head. The torch head comprises
an anode body that is in electrical communication with the positive side of a power
supply and a cathode that is in electrical communication with the negative side
of the power supply. The cathode is further surrounded by a central insulator to
insulate the cathode from the anode body, and similarly, the anode body is surrounded
by an outer insulator to insulate the anode body from a housing, which encapsulates
and protects the torch head and its components from the surrounding environment
during operation. The torch head is further adjoined with a coolant supply tube,
a plasma gas tube, a coolant return tube, and a secondary gas tube, wherein plasma
gas and secondary gas are supplied and cooling fluid is supplied and returned for
operation of the plasma arc torch. Furthermore, a negative lead connection is provided
through the plasma gas tube or a liquid tube to the cathode, and a pilot signal
connection is provided through the anode body to a torch cap.
The torch consumable components comprise an electrode, a tip, a spacer, a distal
anode member, a central anode member, a baffle, a secondary cap, a shield cap,
and a secondary spacer, which are housed by a cartridge body in one form of the
present invention. The tip, central anode member, and distal anode member are anodic
elements that comprise a portion of the positive side of the power supply, whereas
the electrode is a cathodic element that comprises a portion of the negative side
of the power supply. Accordingly, the spacer is disposed between the electrode
and the tip and provides electrical separation between the anodic and cathodic
sides of the power supply, in addition to certain gas distributing functions as
described in greater detail below. The baffle is disposed between the distal anode
member and the shield cap and provides for cooling fluid distribution during operation.
The secondary cap is disposed distally from the tip and provides for secondary
gas distribution, and the secondary spacer provides spacing between the tip and
the secondary cap. Additionally, the shield cap surrounds the other consumable
components and is secured to a torch head using a locking ring or other attachment
member as described in greater detail below.
In another form of the present invention, the consumable components further comprise
a coolant seal and guide disposed between the tip and the secondary cap to direct
and control the flow of cooling fluid. The electrode is centrally disposed within
the cartridge body and is in electrical contact with the cathode along an interior
portion of the electrode. The electrode and cathode are configured such that a
passageway is formed therebetween for the passage of a cooling fluid proximate,
or through an adjacent vicinity of, the electrical contact. The electrode further
defines a central cavity that is in fluid communication with the coolant tube such
that the cathode and electrode, along with other torch components, are properly
cooled during operation. Further, the cartridge body generally distributes cooling
fluid, plasma gas, and secondary gas, while providing separation or dielectric
between various torch components as described in the detailed description that
follows. Moreover, the fluid (cooling, plasma, secondary) is distributed in a coaxial
flow between various torch components, which increases the total amount of flow
and cooling within the plasma arc torch.
As used herein, the term "coaxial" shall be construed to mean a flow that is
annular
and that flows in the same direction at any given radial location from the central
longitudinal axis of the plasma arc torch. Additionally, the term "annular" shall
be construed to mean a flow that is distributed circumferentially about the central
longitudinal axis of the plasma arc torch (although not necessarily continuously).
Therefore, coaxial flow is a flow that is distributed circumferentially about the
central longitudinal axis of the torch and that is flowing in the same direction
at any radial location from the central longitudinal axis. For example, a flow
that crosses over the central longitudinal axis of the plasma arc torch such as
that described in U.S. Pat. Nos. 5,396,043 and 5,653,896, incorporated herein by
reference) is not a coaxial flow. Coaxial flow is shown and described in greater
detail in the detailed description that follows.
The tip is disposed distally from the electrode and is separated therefrom by
the spacer. Similarly, the secondary cap is disposed distally from the tip and
is separated therefrom by the secondary spacer. The distal anode member is generally
disposed around the tip and is in electrical contact with both the tip and the
central anode member. The tip and distal anode member are configured such that
a passageway is formed therebetween for the passage of a cooling fluid proximate,
or through an adjacent vicinity of, the electrical contact. Further, the central
anode member is in electrical contact with the anode body within the torch head
for electrical continuity within the positive, or anodic side of the power supply.
Additionally, the baffle is disposed around the distal anode member, and the shield
cup is disposed around the baffle. Accordingly, passageways are formed between
the cartridge body and the distal anode member, and between the distal anode member
and the baffle for cooling fluid flow. Similarly, a passage is formed between the
baffle and the shield cup for secondary gas flow.
In other forms, several electrode and tip configurations are provided that improve
cooling, provide electrical continuity through the cathode and anode side of the
power supply, respectively, and that provide efficient attachment of the electrode
and tip to the plasma arc torch. Additionally, configurations for consumable cartridges
are provided, wherein a single cartridge containing one or more consumable components
is removed and replaced when the one or more consumable components require replacement,
rather than replacing individual consumable components one at a time. Moreover,
configurations for securing the torch head to adjacent components such as a positioning
tube are also provided by other forms of the present invention.
Further areas of applicability of the present invention will become apparent
from the detailed description provided hereinafter. It should be understood that
the detailed description and specific examples, while indicating the preferred
embodiment of the invention, are intended for purposes of illustration only and
are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description
and the accompanying drawings, wherein:
FIG. 1 is a perspective view of a plasma arc torch constructed in accordance
with the principles of the present invention;
FIG. 2 is an exploded perspective view of a plasma arc torch constructed in
accordance with the principles of the present invention;
FIG. 3 is a longitudinal cross-sectional view, taken along line A—A of
FIG. 1, of the plasma arc torch in accordance with the principles of the present invention;
FIG. 4 is an exploded longitudinal cross-sectional view of the plasma arc torch
of FIG. 3 in accordance with the principles of the present invention;
FIG. 5 is an enlarged longitudinal cross-sectional view of a distal portion
of the plasma arc torch of FIG. 3 in accordance with the principles of the present invention;
FIG. 6 is a longitudinal cross-sectional view of torch consumable components
constructed in accordance with the principles of the present invention;
FIG. 7 is a cross-sectional view of anode members constructed in accordance
with the principles of the present invention;
FIG. 8 is a perspective view of a cartridge body illustrating flexible tabs
for a central anode member constructed in accordance with the principles of the
present invention;
FIG. 9
a is a longitudinal cross-sectional view of a plasma arc torch
illustrating coaxial flow in accordance with the principles of the present invention;
FIG. 9
b is a lateral cross-sectional view of a plasma arc torch illustrating
coaxial flow in accordance with the principles of the present invention;
FIG. 10 is a perspective view of a torch cap of a plasma arc torch and constructed
in accordance with the principles of the present invention;
FIG. 11 is a cutaway perspective view of a plasma arc torch illustrating fluid
passageways in accordance with the principles of the present invention;
FIG. 12
a is a cutaway perspective view of an electrode constructed in
accordance with the principles of the present invention;
FIG. 12
b is a perspective cutaway exploded view of a cathode within a
torch head and an electrode constructed in accordance with the principles of the
present invention;
FIG. 12
c is a cross-sectional view of an electrode disposed around a
cathode in accordance with the principles of the present invention;
FIG. 12
d is a lateral cross-sectional view, taken along line B—B
of FIG. 12
c, illustrating adjacent perimeter surfaces between an electrode
and a cathode in accordance with the principles of the present invention;
FIG. 13
a is a perspective view of a second embodiment of an electrode
constructed in accordance with the principles of the present invention;
FIG. 13
b is a longitudinal cross-sectional view of the electrode of the
second embodiment secured within a plasma arc torch in accordance with the principles
of the present invention;
FIG. 13
c is a lateral cross-sectional view of the electrode of the second
embodiment secured within a plasma arc torch in accordance with the principles
of the present invention;
FIG. 14
a is a perspective view of a third embodiment of an electrode
constructed in accordance with the principles of the present invention;
FIG. 14
b is a longitudinal cross-sectional view of the third electrode
embodiment secured within a plasma arc torch in accordance with the principles
of the present invention;
FIG. 15 is a longitudinal cross-sectional view of a fourth embodiment of an
electrode secured within a plasma arc torch and constructed in accordance with
the principles of the present invention;
FIG. 16 is a longitudinal cross-sectional view of a fifth embodiment of an electrode
secured within a plasma arc torch and constructed in accordance with the principles
of the present invention;
FIG. 17
a is a longitudinal cross-sectional view of a fluid passageway
formed in a cathode adjacent electrical contact with an electrode and constructed
in accordance with the teachings of the present invention;
FIG. 17
b is a lateral cross-sectional view, taken along line C—C
of FIG. 17
a, of the cathode and electrode in accordance with the principles
of the present invention;
FIG. 17
c is a longitudinal cross-sectional view of a fluid passageway
formed by a third element between a cathode and an electrode in accordance with
the principles of the present invention;
FIG. 17
d is a longitudinal cross-sectional view of a fluid passageway
formed by a helical flute between a cathode and an electrode in accordance with
the principles of the present invention;
FIG. 17
e is a longitudinal cross-sectional view of a fluid passageway
formed through a cathode and an electrode in accordance with the principles of
the present invention;
FIG. 17
f is a longitudinal cross-sectional view of a fluid passageway
formed through an electrode in accordance with the principles of the present invention;
FIG. 18 is a longitudinal cross-sectional view of an electrode holder constructed
in accordance with the teachings of the present invention;
FIG. 19 is a perspective view of a tip constructed in accordance with the principles
of the present invention;
FIG. 20 is a side view of the tip of FIG. 19 in accordance with the principles
of the present invention;
FIG. 21 is a longitudinal cross-sectional view of the tip, taken along line
D—D of FIG. 20, in accordance with the principles of the present invention;
FIG. 22 is a top view of the tip of FIG. 19 in accordance with the principles
of the present invention;
FIG. 23 is a cross-sectional view of the tip disposed adjacent a distal anode
member in accordance with the principles of the present invention;
FIG. 24
a is a cross-sectional view of a fluid passageway formed in a
tip adjacent electrical contact with the distal anode member in accordance with
the principles of the present invention;
FIG. 24
b is a cross-sectional view, taken along line E—E of FIG.
24
a, of the tip and distal anode member in accordance with the principles
of the present invention;
FIG. 24
c is a cross-sectional view of a fluid passageway formed by a
third member disposed between a tip and a distal anode member in accordance with
the principles of the present invention;
FIG. 24
d is a cross-sectional view of a fluid passageway formed between
by a helical flute between a tip and a distal anode member in accordance with the
principles of the present invention;
FIG. 25
a is a perspective view of a secondary cap constructed in accordance
with the principles of the present invention;
FIG. 25
b is a top view of a secondary cap constructed in accordance with
the principles of the present invention;
FIG. 26
a is a longitudinal side cross-sectional view of secondary gas
bleed passageways constructed in accordance with the principles of the present invention;
FIG. 26
b is a top view of a shield cap comprising secondary gas bleed
passageways and constructed in accordance with the principles of the present invention;
FIG. 26
c is a longitudinal side cross-sectional view of an alternate
torch embodiment for bleeding secondary gas and constructed in accordance with
the principles of the present invention;
FIG. 27
a is a perspective view of a secondary cap spacer constructed
in accordance with the principles of the present invention;
FIG. 27
b is a side view of the secondary spacer constructed in accordance
with the principles of the present invention;
FIG. 28
a is a perspective view of a consumables cartridge constructed
in accordance with the principles of the present invention;
FIG. 28
b is a longitudinal cross-sectional view of the consumables cartridge,
taken along line E—E of FIG. 28
a, in accordance with the principles
of the present invention;
FIG. 29 is a longitudinal cross-sectional view of a second embodiment of a consumables
cartridge constructed in accordance with the principles of the present invention;
FIG. 30 is a longitudinal cross-sectional view of a stepped cartridge attachment
illustrating cooling fluid passageways and constructed in accordance with the principles
of the present invention;
FIG. 31 is a longitudinal cross-sectional view of a stepped cartridge attachment
illustrating gas passageways and constructed in accordance with the principles
of the present invention;
FIG. 32
a is a longitudinal cross-sectional view of a face seal cartridge
attachment illustrating cooling fluid passageways and constructed in accordance
with the principles of the present invention;
FIG. 32
b is a longitudinal cross-sectional view of a face seal cartridge
attachment illustrating gas passageways and constructed in accordance with the
principles of the present invention;
FIG. 33
a is a longitudinal cross-sectional view of a straight cartridge
attachment illustrating cooling fluid passageways and constructed in accordance
with the principles of the present invention;
FIG. 33
b is a longitudinal cross-sectional view of a straight cartridge
attachment illustrating gas passageways and constructed in accordance with the
principles of the present invention;
FIG. 34
a is an enlarged longitudinal cross-sectional view of a ball-lock
mechanism connected and constructed in accordance with the principles of the present invention;
FIG. 34
b is an enlarged longitudinal cross-sectional view of a ball-lock
mechanism disconnected and constructed in accordance with the principles of the
present invention;
FIG. 35
a is a longitudinal cross-sectional view of a torch head having
alignment geometry and constructed in accordance with the principles of the present invention;
FIG. 35
b is a top view of a torch head having alignment geometry and
constructed in accordance with the principles of the present invention;
FIG. 36 is a longitudinal cross-sectional view of a second plasma arc torch
embodiment constructed in accordance with the teachings of the present invention;
FIG. 37 is a longitudinal cross-sectional view of a torch head of the second
plasma arc torch embodiment in accordance with the principles of the present invention;
FIG. 38 is a longitudinal cross-sectional view of consumable components of the
second plasma arc torch embodiment in accordance with the principles of the present invention;
FIG. 39
a is a perspective view of a cartridge body constructed in accordance
with the teachings of the present invention;
FIG. 39
b is a proximal perspective view of a cartridge body constructed
in accordance with the teachings of the present invention;
FIG. 39
c is a top view of a cartridge body constructed in accordance
with the teachings of the present invention;
FIG. 39
d is a bottom view of a cartridge body constructed in accordance
with the teachings of the present invention;
FIG. 40 is a perspective view of a central anode member constructed in accordance
with the teachings of the present invention;
FIG. 41 is a perspective view of a distal anode member constructed in accordance
with the teachings of the present invention;
FIG. 42 is an exploded perspective view of a tip, a tip guide, and a tip seal
constructed in accordance with the teachings of the present invention;
FIG. 43 is a side view of a tip assembly constructed in accordance with the
teachings of the present invention;
FIG. 44 is a longitudinal cross-sectional view of a plasma arc torch illustrating
the cooling fluid flow in accordance with the principles of the present invention;
FIG. 45 is a longitudinal cross-sectional view of a plasma arc torch illustrating
the plasma gas flow in accordance with the principles of the present invention;
FIG. 46 is a longitudinal cross-sectional view of a plasma arc torch illustrating
the secondary gas flow in accordance with the principles of the present invention;
FIG. 47
a is a longitudinal cross-sectional view of a consumables cartridge
constructed in accordance with the teachings of the present invention;
FIG. 47
b is a longitudinal cross-sectional view of a second embodiment
of a consumables cartridge constructed in accordance with the teachings of the
present invention;
FIG. 47
c is a longitudinal cross-sectional view of a third embodiment
of a consumables cartridge constructed in accordance with the teachings of the
present invention;
FIG. 47
d is a longitudinal cross-sectional view of a fourth embodiment
of a consumables cartridge constructed in accordance with the teachings of the
present invention;
FIG. 47
e is a longitudinal cross-sectional view of a fifth embodiment
of a consumables cartridge constructed in accordance with the teachings of the
present invention;
FIG. 47
f is a longitudinal cross-sectional view of a sixth embodiment
of a consumables cartridge constructed in accordance with the teachings of the
present invention;
FIG. 48
a is a longitudinal cross-sectional view of a consumables assembly
constructed in accordance with the teachings of the present invention;
FIG. 48
b is a longitudinal cross-sectional view of a second embodiment
of a consumables assembly in accordance with the principles of the present invention;
FIG. 48
c is a longitudinal cross-sectional view of a third embodiment
of a consumables assembly in accordance with the principles of the present invention;
FIG. 48
d is a longitudinal cross-sectional view of a fourth embodiment
of a consumables assembly in accordance with the principles of the present invention;
FIG. 48
e is a longitudinal cross-sectional view of a fifth embodiment
of a consumables assembly in accordance with the principles of the present invention;
FIG. 48
f is a longitudinal cross-sectional view of a sixth embodiment
of a consumables assembly in accordance with the principles of the present invention;
FIG. 48
g is a longitudinal cross-sectional view of a seventh embodiment
of a consumables assembly in accordance with the principles of the present invention;
FIG. 49 is an exploded longitudinal cross-sectional view of torch head connections
constructed in accordance with the teachings of the present invention;
FIG. 50 is a longitudinal cross-sectional view of another plasma arc torch embodiment
constructed in accordance with the teachings of the present invention; and
FIG. 51 is a schematic view illustrating a plasma arc torch employed within
a plasma arc torch cutting system in accordance with the various embodiments of
the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description of the preferred embodiments is merely exemplary in
nature and is in no way intended to limit the invention, its application, or uses.
Referring to the drawings, a plasma arc torch according to the present
invention is illustrated and indicated by reference numeral
10 in FIG. 1
through FIG. 6. The plasma arc torch
10 generally comprises a torch head
12 disposed at a proximal end
14 of the plasma arc torch
10
and a plurality of consumable components
16 secured to the torch head
12
and disposed at a distal end
18 of the plasma arc torch
10 as shown.
As used herein, a plasma arc torch should be construed by those skilled in the
art to be an apparatus that generates or uses plasma for cutting, welding, spraying,
gouging, or marking operations, among others, whether manual or automated. Accordingly,
the specific reference to plasma arc cutting torches or plasma arc torches should
not be construed as limiting the scope of the present invention. Furthermore, the
specific reference to providing gas to a plasma arc torch should not be construed
as limiting the scope of the present invention, such that other fluids, e.g. liquids,
may also be provided to the plasma arc torch in accordance with the teachings of
the present invention. Additionally, proximal direction or proximally is the direction
towards the torch head
12 from the consumable components
16 as depicted
by arrow A′, and distal direction or distally is the direction towards the
consumable components
16 from the torch head
12 as depicted by arrow B′.
Torch Head
Referring more specifically to FIG. 5, the torch head
12 includes
an anode body
20 that is in electrical communication with the positive side
of a power supply (not shown), and a cathode
22 that is in electrical communication
with the negative side of the power supply. The cathode
22 is further surrounded
by a central insulator
24 to insulate the cathode
22 from the anode
body
20, and similarly, the anode body
20 is surrounded by an outer
insulator
26 to insulate the anode body
20 from a housing
28,
which encapsulates and protects the torch head
12 and its components from
the surrounding environment during operation. The torch head
12 is further
adjoined with a coolant supply tube
30, a plasma gas tube
32, a coolant
return tube
34, and a secondary gas tube
35 (shown in their entirety
in FIGS. 1 and 2), wherein plasma gas and secondary gas are supplied to and cooling
fluid is supplied to and returned from the plasma arc torch
10 during operation
as described in greater detail below.
The cathode
22 preferably defines a cylindrical tube having a central
bore
36 that is in fluid communication with the coolant supply tube
30
at a proximal portion
38 of the torch head
12. The central bore
36
is also in fluid communication with a cathode cap
40 and a coolant tube
42 disposed at a distal portion
44 of the torch head
12. Generally,
the coolant tube
42 serves to distribute the cooling fluid and the cathode
cap
40 protects the distal end of the cathode
22 from damage during
replacement of the consumable components
16 or other repairs. As further
shown, the cathode
22 comprises an internal annular ring
46 that
engages a proximal groove
48 formed in the cathode cap
40. As further
shown, a flexible collar
49 formed on the cathode cap
40 engages
the annular ring
46 such that the cathode cap
40 is properly secured
within the cathode
22. To secure the coolant tube
42, the cathode
cap
40 defines an internal shoulder
50 against which an annular ring
52 of the coolant tube
42 abuts. Further, the coolant tube
42
defines an o-ring groove
54 that houses an o-ring
56 to seal and
retain the interface between the cathode cap
40 and the coolant tube
42.
Preferably, the coolant tube
42 is formed of a durable material such as
stainless steel, and the cathode cap
40 is insulative and is preferably
formed of a material such as Torlon® or other material known in the art that
is also capable of operating at relatively high temperatures (For example, approximately
250° C. to approximately 350° C.).
The central insulator
24 preferably defines a cylindrical tube having
an internal bore
60 that houses the cathode
22 as shown. The cathode
22 defines a proximal external shoulder
62 that abuts a proximal
internal shoulder
64 of the central insulator
24 to position of the
cathode
22 along the central longitudinal axis X of the plasma arc torch
10. Further, the cathode
22 comprises an external o-ring groove
65
that houses an o-ring
66 to seal the interface between the cathode
22
and the central insulator
24. The central insulator
24 is further
disposed within the anode body
20 as shown along a central portion
68
and also engages a torch cap
70 that accommodates the coolant supply tube
30, the plasma gas tube
32, and the coolant return tube
34.
Electrical continuity for electric signals such as a pilot return is provided
through a contact
72 disposed between the torch cap
70 and the anode
body
20. The contact
72 comprises a proximal flange
74 that
abuts a recessed shoulder
76 formed in the torch cap
70 and a distal
end
78 that engages the anode body
20 as shown. Preferably, the contact
72 is threaded into the anode body
20, however, other attachment
methods such as a press fit or soldering may also be used while remaining within
the scope of the present invention. Additionally, a distal annular wall
80
of the torch cap
70 abuts an o-ring
82 disposed within an o-ring
groove
84 within the outer insulator
26 to seal the interface between
the torch cap
70 and the outer insulator
26. Similarly, a distal
internal wall
86 of the housing
28 abuts an o-ring
88 disposed
within an o-ring groove
90 of the consumable components
16 to seal
an interface between the housing
28 and the consumable components
16.
Additional o-ring grooves
92 with corresponding o-rings (not shown) are
provided between a plurality of interfaces as shown to seal the fluid (plasma gas,
secondary gas, cooling fluid) passageways and are not described in further detail
herein for purposes of clarity.
Alternately, electrical continuity for the pilot return or other electrical
signals may be provided directly through an interface between the torch cap
70
and the anode body
20 using detents engaging a shoulder as shown and described
in U.S. Pat. No. 6,163,008, which is commonly assigned with the present application
and the contents of which are incorporated herein by reference. The detents may
be incorporated on the torch cap
70 or the anode body
20 with a corresponding
shoulder and cap on the anode body
20 or torch cap
70, respectively.
Further, the detents provide a connection that is relatively simple and easy to
engage and disengage. Similarly, other components within the plasma arc torch
10
may also employ the detents and shoulder for their respective connections while
remaining within the scope of the present invention.
Consumable Components
The consumable components
16, which are shown in greater detail in FIG.
6, comprise an electrode
100, a tip
102, and a spacer
104
disposed between the electrode
100 and the tip
102 as shown. The
spacer
104 provides electrical separation between the cathodic electrode
100 and the anodic tip
102, and further provides certain gas distributing
functions as described in greater detail below. The consumable components
16
further comprise a cartridge body
106, which generally houses and positions
the other consumable components
16. The cartridge body
106 also distributes
plasma gas, secondary gas, and cooling fluid during operation of the plasma arc
torch
10, which is described in greater detail below. Additionally, the
consumable components
16 comprise a distal anode member
108 and a
central anode member
109 to form a portion of the anodic side of the power
supply by providing electrical continuity to the tip
102. A baffle
110
is also shown disposed between the distal anode member
108 and a shield
cap
114, which forms fluid passageways for the flow of a cooling fluid as
described in greater detail below. Further, the consumable components
16
comprise a secondary cap
112 for the distribution of the secondary gas and
a secondary spacer
116 that separates the secondary cap
112 from
the tip
102. A locking ring
117 is shown disposed around the proximal
end portion of the consumable components
16, which is used to secure the
consumable components
16 to the torch head
12 (not shown).
The electrode
100 is centrally disposed within the cartridge body
106
and is in electrical contact with the cathode
22 (FIG. 5) along an interior
portion
118 of the electrode
100 as described in greater detail below.
The electrode
100 further defines a distal cavity
120 that is in
fluid communication with the coolant tube
42 (FIG. 5) and an external shoulder
122 that abuts the spacer
104 for proper positioning along the central
longitudinal axis X of the plasma arc torch
10. The cartridge body
106
further comprises an internal annular ring
124 that abuts a proximal end
126 of the electrode
100 for proper positioning of the electrode
100 along the central longitudinal axis X of the plasma arc torch
10.
Additionally, the connection between the cartridge body
106 and the cathode
22 may employ the detents and shoulder as previously described while remaining
within the scope of the present invention. In addition to positioning the various
consumable components
16, the cartridge body
106 also separates anodic
member (e.g., central anode member
109) from cathodic members (e.g., electrode
100). Accordingly, the cartridge body
106 is an insulative material
such as PEEK® or other similar material commonly known in the art that is
further capable of operating at relatively high temperatures.
For the distribution of cooling fluid as described in greater detail below, the
cartridge body
106 defines an upper chamber
128 and a plurality of
passageways
130 that extend through the cartridge body
106 and into
an inner cooling chamber
132 formed between the cartridge body
106
and the distal anode member
108. Preferably, the passageways
130
(shown dashed) are angled radially outward in the distal direction from the upper
chamber
128 (shown dashed) to reduce any amount of dielectric creep that
may occur between the electrode
100 and the distal anode member
108.
Additionally, outer axial passageways
133 are formed in the cartridge body
106 that provide for a return of the cooling fluid, which is further described
below. For the distribution of plasma gas, the cartridge body
106 defines
a plurality of distal axial passageways
134 that extend from a proximal
face
136 of the cartridge body
106 to a distal end
138 thereof,
which are in fluid communication with the plasma gas tube
32 (not shown)
and passageways formed in the tip
102 as described in greater detail below.
Additionally, a plurality of proximal axial passageways
140 are formed through
the cartridge body
106 that extend from a recessed proximal face
142
to a distal outer face
144 for the distribution of a secondary gas, which
is also described in greater detail below. Near the distal end of the consumables
cartridge
16, an outer fluid passage
148 is formed between the distal
anode member
108 and the baffle
110 for the return of cooling fluid
as described in greater detail below. Accordingly, the cartridge body
106
performs both cooling fluid distribution functions in addition to plasma gas and
secondary gas distribution functions.
As shown in FIGS. 5 and 6, the distal anode member
108 is disposed between
the cartridge body
106 and the baffle
110 and is in electrical contact
with the tip
102 at a distal portion and with the central anode member
109
at a proximal portion. Further, the central anode member
109 is in electrical
contact with a distal portion of the anode body
20. Preferably, a canted
coil spring (not shown) is disposed within a groove
146 to provide electrical
contact between the central anode member
109 and the anode body
20.
Alternately, electrical continuity for the pilot return or other electrical signals
may be provided directly through an interface between the central anode member
109 and the anode body
20 using detents engaging a shoulder as shown
and described in U.S. Pat. No. 6,163,008, which is commonly assigned with the present
application and the contents of which are incorporated herein by reference. The
detents may be incorporated on the central anode member
109 or the anode
body
20 with a corresponding shoulder and cap on the anode body
20
or central anode member
109, respectively. Accordingly, the anode body
20,
the distal anode member
108, the central anode member
109, and the
tip
102 form the anode, or positive, potential for the plasma arc torch
10.
The detents are illustrated in greater detail in FIGS. 7 and 8, wherein the central
anode member
109 is preferably secured to the cartridge body
106
using detents
260 as shown. (Certain portions of the plasma arc torch
10
and the cartridge body
106 are omitted for purposes of clarity). The detents
260 extend radially inward to engage a shoulder
262 formed at the
proximal end of the cartridge body
106 that extends radially outward as
shown. Alternately, the detents
260 may extend radially outward while the
shoulder
262 extends radially inward in another form of the present invention.
Additionally, the detents
260 are formed in flexible tabs
264 of
the central anode member
109 as shown, wherein the tabs
264 provide
additionally flexibility for assembly of the central anode member
109 to
the cartridge body
106.
Referring again to FIG. 6, the shield cap
114 surrounds the baffle
110 as shown, wherein a secondary gas passage
150 is formed therebetween.
Generally, the secondary gas flows from the proximal axial passageways
140
formed in the cartridge body
106 into the secondary gas passage
150
and through the secondary cap
112, as described in greater detail below,
to stabilize the plasma stream exiting the secondary cap
112 in operation.
The shield cap
114 further positions the secondary cap
112, wherein
the secondary cap
112 defines an annular shoulder
152 that engages
a conical interior surface
154 of the shield cap
114. Alternately,
the shield cap
114 may define a rounded corner (not shown) rather than a
conical surface to engage the annular shoulder
152 for an improved fit.
Similarly, the secondary cap
112 may alternately define a rounded corner
that engages the conical interior surface
154 of the shield cap
114
