US2811690A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for testing helix pitch
Assignee: AT&T Inc
•
Filing: 1953-12-30
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Granted: 1957-10-29
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Expires: 1973-12-30
Abstract
No abstract record available.
Inventors
- 👤 George A Sargent
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:52
CPC Classifications
H; H01; H01J; H01J23/00; H01J23/16; H01J23/24; H01J23/26
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2065118A
Cited
US1992013A
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US2124579A
Cited
US2415789A
Cited
US2435985A
Cited
US2508494A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-10-28 | 1961-04-29 | 1961-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-10-28 | 1965-04-29 | 1965-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-10-28 | 1969-04-29 | 1969-10-29 | $7700.00 | Window Closed / Lapsed |