Patent US1587520A successfully refreshed from Google Patents.
US1587520A
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Nonresonant system
Assignee: AT&T Inc
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Filing: 1919-02-03
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Granted: 1926-06-08
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Expires: 1939-02-03
Abstract
No abstract record available.
Inventors
- 👤 Ralph V L Hartley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:54
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/02; H03K3/04; H03K3/16; H03B; H03B7/00; H03B7/02; H03B7/04
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) | 1929-06-07 | 1929-12-07 | 1930-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1933-06-07 | 1933-12-07 | 1934-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1937-06-07 | 1937-12-07 | 1938-06-08 | $7700.00 | Window Closed / Lapsed |