US3553422A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plasma arc welding method and apparatus
Assignee: Air Products and Chemicals Inc
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Filing: 1969-04-28
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Granted: 1971-01-05
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Expires: 1989-04-28
Abstract
Abstract Disclosed is a method and apparatus for minimizing the double arcing phenomena often associated with plasma arc torches. The invention is characterized in that by moving the shielding gas rapidly across the face of the torch tip at an angle to the plasma arc, the double arcing phenomena is minimized or eliminated.
Inventors
- 👤 George H Mccoy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:24
CPC Classifications
H; H05; H05H; H05H1/00; H05H1/24; H05H1/26; H05H1/32; H05H1/34; B; B23; B23K; B23K10/00; B23K10/02; H05H1/341; H05H1/3478; H05H1/38
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
176 words
In a plasma arc welding torch of the type comprising a handle, a torch head secured to the handle, a pair of electrodes including a cathode and a tip serving as an anode disposed within the head for initiating an arc, means for supplying arc gas through the tip to the electric arc for creating an arc plasma and means for introducing shielding gas to the torch to be directed at the arc, the improvement which comprises; a nozzle containing a central passage, the nozzle secured to the torch head and surrounding at least the lower portion of the torch tip, the tip having a rounded configuration at the gas discharge end, the central passage in the nozzle being spaced apart from the tip and defining a conduit for shielding gas to flow around the tip, means on the surface of the central passage to constrict and direct the shielding gas across the end of the tip toward the plasma arc at an angle greater than parallel to but less than normal to the plasma arc.
Claim 2
Dependent Claim
176 words
In a plasma arc welding torch of the type comprising a handle, a torch head secured to the handle, a pair of electrodes including a cathode and a tip serving as an anode disposed within the head for initiating an arc, means for supplying arc gas through the tip to the electric arc for creating an arc plasma and means for introducing shielding gas to the torch to be directed at the arc, the improvement which comprises; a nozzle containing a central passage, the nozzle secured to the torch head and surrounding at least the lower portion of the torch tip, the tip having a rounded configuration at the gas discharge end, the central passage in the nozzle being spaced apart from the tip and defining a conduit for shielding gas to flow around the tip, means on the surface of the central passage to constrict and direct the shielding gas across the end of the tip toward the plasma arc at an angle greater than parallel to but less than normal to the plasma arc.
Claim 3
Dependent Claim
43 words
A torch according to claim 1 wherein there is provided a collar disposed around the tip defining a shielding gas surge chamber communicating with the means for supplying the shielding gas and spaced above the point where the plasma arc leaves the tip.
Claim 4
Dependent Claim
82 words
A plasma arc torch according to claim 2 wherein the end of the nozzle through which the plasma arc and shielding gas are directed has an internal configuration comprising an upper frustoconical surface leading to a cylindrical surface at the discharge end of the nozzle, the cylindrical discharge opening surrounding the lower end of the tip, the space defined by the frustoconical surface and the rounded end of the tip serving to constrict and direct the shielding gas toward the plasma arc.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-04 | 1974-07-06 | 1975-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-04 | 1978-07-06 | 1979-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-04 | 1982-07-06 | 1983-01-05 | $7700.00 | Window Closed / Lapsed |