Patent US1856138A successfully refreshed from Google Patents.
US2087316A
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Volume control system
Assignee: AT&T Inc
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Filing: 1935-12-11
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Granted: 1937-07-20
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Expires: 1955-12-11
Abstract
No abstract record available.
Inventors
- 👤 Jr Stephen Doba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:52
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/62; H04B1/64; H03; H03G; H03G7/00; H03G7/002; H03G7/004; H03G7/02
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) | 1940-07-19 | 1941-01-18 | 1941-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1944-07-19 | 1945-01-18 | 1945-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1948-07-19 | 1949-01-18 | 1949-07-20 | $7700.00 | Window Closed / Lapsed |