Patent US2773933A successfully refreshed from Google Patents.
US2773933A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Third order pressure gradient responsive microphone
Assignee: Individual
•
Filing: 1954-02-01
•
Granted: 1956-12-11
•
Expires: 1974-02-01
Abstract
No abstract record available.
Inventors
- 👤 Mones E Hawley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:26
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/32; H04R1/40; H04R1/406
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1844487A
Cited
US2475782A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-12-11 | 1960-06-11 | 1960-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-12-11 | 1964-06-11 | 1964-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-12-11 | 1968-06-11 | 1968-12-11 | $7700.00 | Window Closed / Lapsed |