US3567898A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plasma arc cutting torch
Assignee: Crucible Inc
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Filing: 1968-07-01
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Granted: 1971-03-02
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Expires: 1988-07-01
Abstract
Abstract Water introduced to a plasma jet near its base dissociates into hydrogen and oxygen, adding material and force to the jet and tending to make it more straight-sided and stable. Near the tip of the plasma jet, the hydrogen and oxygen recombine, affording heat. Materials difficult to cut with a torch using known methods, such as inch-thick plates of stainless steel or highspeed tool steel, may be cut at substantially higher traverse rates. Moreover, the kerf is straight-sided and lustrous, rather than being concave and having a dull, oxidized appearance.
Inventors
- 👤 Samuel Fein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:52
CPC Classifications
H; H05; H05H; H05H1/00; H05H1/24; H05H1/26; H05H1/32; H05H1/42; B; B23; B23K; B23K10/00; H05H1/34; H05H1/3421
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
25 words
A method as defined in claim 1, characterized in that said jet is an arc plasma jet having a temperature of about 15,000-60, 000* F.
Claim 2
Dependent Claim
22 words
A method as defined in claim 2, further characterized in that said piece of metal melts at about 2,500* F. or higher.
Claim 3
Dependent Claim
53 words
A method as defined in claim 3, characterized in that said metal is selected from the group consisting of stainless steel and high-speed tool steel, and in that cutting is effected by causing relative movement between said jet and said piece of metal at a traverse rate of about 20-30 inches per minute.
Claim 4
Dependent Claim
36 words
A method as defined in claim 2, characterized in that said jet is established between a gas-shielded electrode and a piece of metal to be cut, said flow of water being about 120 milliliters per minute.
Claim 5
Dependent Claim
108 words
In apparaTus for cutting a plate of metal, the combination with: an electrode; means for establishing between said electrode and said plate a direct current arc; means for directing, into said arc, gases to be heated thereby to form a plasma jet; means for causing relative motion between said jet and said plate over a predetermined path while maintaining said jet in spaced relation to said plate improvement comprising: means for introducing to penetrate into said plasma jet in the vicinity of its base a flow of liquid water in an amount that said water becomes dissociated into hydrogen and oxygen at a temperature of about 15,000-60,000* F.
Claim 6
Dependent Claim
49 words
The combination as defined in claim 6, characterized in that said means for introducing into said plasma jet a flow of liquid water comprising a capillary line contained within a passage for blanketing said jet, said capillary having an outlet in the vicinity of the base of said electrode.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |