US3902035A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for arc working work-pieces with a rotating arc
Assignee: Bv Koninklijke 'de Schelde'nl197212017216360 Mij
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Filing: 1973-11-30
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Granted: 1975-08-26
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Expires: 1993-11-30
Abstract
Abstract This invention relates to an apparatus for performing plasma arc welding by a process in which the plasma arc travels about a closed path or orbit on the work-piece. More particularly, the invention provides a plasma arc welding apparatus useful for performing butt welded joining of cylindrical work-pieces, such as pipes and rods, and for welding tubes to tube sheets. The invention utilizes an annular slot nozzle which is operated with a gas for maintaining a plasma arc, and a generally ringshaped electrode positioned in circumferentially opposed relation to the weld path. A magnetic field interacting with the plasma arc between the electrode and the work-piece causes the arc to travel around the weld path to perform welding therealong.
Inventors
- 👤 Johannus J Broodman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:06
CPC Classifications
B; B23; B23K; B23K9/00; B23K9/08
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
155 words
A plasma arc welding apparatus, which comprises means defining a generally annular slot nozzle disposed in circumferentially opposed, spaced-apart relation to a closed curve weld path on a work piece, said nozzle communicating with a gas supply for blowing pressurized gas as a gas jet through said slot to said weld path; a generally ring-shaped electrode positioned within said nozzle defining means in circumferentially opposed, spaced-apart relation to said slot and said weld path, said electrode and said workpiece being disposed for connection to a source of electric energy to establish a plasma arc between said electrode and weld path on said workpiece by interaction of said arc and said gas jet blowing through said slot reducing the cross section of the arc with respect to a free burning arc; and means establishing a magnetic field interacting with said plasma arc and causing said arc to travel around said weld path, to perform welding therealong.
Claim 2
Dependent Claim
155 words
A plasma arc welding apparatus, which comprises means defining a generally annular slot nozzle disposed in circumferentially opposed, spaced-apart relation to a closed curve weld path on a work piece, said nozzle communicating with a gas supply for blowing pressurized gas as a gas jet through said slot to said weld path; a generally ring-shaped electrode positioned within said nozzle defining means in circumferentially opposed, spaced-apart relation to said slot and said weld path, said electrode and said workpiece being disposed for connection to a source of electric energy to establish a plasma arc between said electrode and weld path on said workpiece by interaction of said arc and said gas jet blowing through said slot reducing the cross section of the arc with respect to a free burning arc; and means establishing a magnetic field interacting with said plasma arc and causing said arc to travel around said weld path, to perform welding therealong.
Claim 3
Dependent Claim
25 words
An apparatus according to claim 1 wherein said electrode is a single turn inductor and constitutes a part of the means establishing said magnetic field.
Claim 4
Dependent Claim
34 words
An apparatus according to claim 1 wherein the means defining said nozzle includes means defining a single turn inductor and disposed for connection to a source of electric energy to establish said magnetic field.
Claim 5
Dependent Claim
28 words
An apparatus according to claim 1 wherein said electrode is positioned concentrically with respect to a circular weld path defined by the abutting ends of two cylindrical workpieces.
Claim 6
Dependent Claim
23 words
An apparatus according to claim 1 wherein said electrode and nozzle have parts connected for pivotal movement to accommodate insertion of the workpiece.
Claim 7
Dependent Claim
32 words
An apparatus according to claim 1 wherein said electrode and nozzle slot are positioned concentrically with respect to a circular weld path located in a plane generally parallel to the nozzle slot.
Claim 8
Dependent Claim
29 words
An apparatus according to claim 5 including a housing supporting said electrode and nozzle, said housing having pivotally connected parts moveable in unison with said electrode and nozzle parts.
Claim 9
Dependent Claim
28 words
An apparatus according to claim 5 including an insulator positioned between said nozzle parts to interrupt current flow therebetween and make said nozzle define a single turn inductor.
Claim 10
Dependent Claim
28 words
An apparatus according to claim 5 including an insulator positioned between said electrode parts to interrupt current flow therebetween and make said electrode define a single turn inductor.
Claim 11
Independent Claim
82 words
A method of plasma arc welding which comprises establishing a gas flow through an annuLar slot nozzle positioned in circumferentially opposed spaced-apart relation to a closed curve weld path on a workpiece; establishing a plasma arc through said gas flow and between said workpiece weld path and a ring-shaped electrode positioned in circumferentially opposed spaced-apart relation to said path; and establishing a magnetic field interacting with said plasma arc and causing said arc to travel around said path to perform welding therealong.
Claim 12
Independent Claim
82 words
A method of plasma arc welding which comprises establishing a gas flow through an annuLar slot nozzle positioned in circumferentially opposed spaced-apart relation to a closed curve weld path on a workpiece; establishing a plasma arc through said gas flow and between said workpiece weld path and a ring-shaped electrode positioned in circumferentially opposed spaced-apart relation to said path; and establishing a magnetic field interacting with said plasma arc and causing said arc to travel around said path to perform welding therealong.
Claim 13
Dependent Claim
21 words
A method of plasma arc welding according to claim 10 wherein said plasma arc is laterally confined by said slot nozzle.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |