US1737883A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diaphragm especially for sound receiving and radiating apparatus
Assignee: Signal GmbH
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Filing: 1925-02-09
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Granted: 1929-12-03
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Expires: 1945-02-09
Abstract
No abstract record available.
Inventors
- 👤 Hecht Heinrich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 19:49
CPC Classifications
H; H04; H04R; H04R7/00; H04R7/02; H04R7/04; H04R7/06
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) | 1932-12-02 | 1933-06-03 | 1933-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1936-12-02 | 1937-06-03 | 1937-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1940-12-02 | 1941-06-03 | 1941-12-03 | $7700.00 | Window Closed / Lapsed |