US3898418A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of welding metals under water
Assignee: National Institute for Materials Science
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Filing: 1973-12-07
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Granted: 1975-08-05
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Expires: 1993-12-07
Abstract
Abstract The underwater welding of metal surfaces using a plasma arc, wherein the plasma arc, plasma gas and weld part are sealed with a layer of water glass.
Inventors
- 👤 Atsushi Hasui
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 00:06
CPC Classifications
B; B23; B23K; B23K9/00; B23K9/0061; B23K10/00; B23K10/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
110 words
A method of welding metal surfaces under water with a plasma torch located opposite to the weld zone of said metal surfaces to be welded comprising generating a plasma arc between the weld zone of said metal surfaces under water and a cathode of said plasma torch, jetting a layer of compressed plasma gas from the forward end of said plasma torch around said weld zone and said plasma arc to thereby enclose said weld zone and said plasma arc, enclosing said layer of compressed plasma gas with a layer of water glass and, welding said metal surfaces by the plasma arc developed across said electrode and said mEtal surfaces.
Claim 2
Independent Claim
110 words
A method of welding metal surfaces under water with a plasma torch located opposite to the weld zone of said metal surfaces to be welded comprising generating a plasma arc between the weld zone of said metal surfaces under water and a cathode of said plasma torch, jetting a layer of compressed plasma gas from the forward end of said plasma torch around said weld zone and said plasma arc to thereby enclose said weld zone and said plasma arc, enclosing said layer of compressed plasma gas with a layer of water glass and, welding said metal surfaces by the plasma arc developed across said electrode and said mEtal surfaces.
Claim 3
Dependent Claim
42 words
The method of claim 1 wherein the water glass has a viscosity of 10 to 1,000 centipoises and is flowed at a rate of 0.2 liter/min. to 1.2 liters/min. so as to surround the outer side of said layer of plasma gas.
Claim 4
Dependent Claim
48 words
The method of claim 1 wherein the plasma gas is jetted out at a flow rate of 2 to 6 liters per minute in the steady state, and at the initiation of the operation, is jetted out at a flow rate of at least 8 liters per minute.
Claim 5
Dependent Claim
32 words
The method of claim 1 which further comprises generating a subsidiary arc between said cathode and an anode of said plasma torch and jetting said compressed plasma gas across said subsidiary arc.
Claim 6
Dependent Claim
26 words
The method of claim 1 wherein said water glass includes an arc stabilizer selected from the group consisting of calcium carbonate, potassium silicate, and titanium oxide.
Claim 7
Dependent Claim
23 words
The method of claim 1 wherein said water glass further contains finely divided particles of a gas-generating substance selected from starch or cellulose.
Claim 8
Dependent Claim
40 words
The method of claim 1 wherein said layer of water glass is heated by the heat of said plasma gas to form a solid porous wall to thereby completely shield the plasma arc and welding zone from the surrounding water.
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) | 1978-08-04 | 1979-02-03 | 1979-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-04 | 1983-02-03 | 1983-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-04 | 1987-02-03 | 1987-08-05 | $7700.00 | Window Closed / Lapsed |