US3761370A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of hardening the surface of workpieces made of iron and steel
Assignee: Individual
•
Filing: 1971-09-20
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Granted: 1973-09-25
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Expires: 1991-09-20
Abstract
Abstract A METHOD OF SELECTIVELY IONITRIDING A METAL WORKPIECE COMPRISING ESTABLISHING AN ELECTRICAL POTENTIAL OF ONE VALUE BETWEEN THE WORKPIECE AND THE TREATMENT CHAMBER AND ALSO ESTABLISHING AN ELECTRICAL POTENTIAL OF A LESSER VALUE BETWEEN A SELECTED PORTION OF THE WORKPIECE AND AN INTERMEDIATE ELECTRODE MEMBER.
Inventors
- 👤 K Keller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:07
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32431; H01J37/32623; C; C23; C23C; C23C8/00; C23C8/06; C23C8/36; C23C8/38; H01J2237/00; H01J2237/32; H01J2237/33; H01J2237/338; H01J2237/3387
Claims Analysis
Total Claims: 0
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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) | 1976-09-24 | 1977-03-26 | 1977-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-24 | 1981-03-26 | 1981-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-24 | 1985-03-26 | 1985-09-25 | $7700.00 | Window Closed / Lapsed |