US2551556A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acoustic diaphragm with plural voice coil supports
Assignee: E D MCCURDY
•
Filing: 1945-09-12
•
Granted: 1951-05-01
•
Expires: 1965-09-12
Abstract
No abstract record available.
Inventors
- 👤 Joseph B Brennan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:35
CPC Classifications
H; H04; H04R; H04R9/00; H04R9/06; H04R9/063
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2007746A
Cited
US1947749A
Cited
GB317134A
Cited
US1800573A
Cited
US1811367A
Cited
US1936918A
Cited
US1923965A
Cited
US1872583A
Cited
US2034882A
Cited
US2269284A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-04-30 | 1954-10-30 | 1955-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-04-30 | 1958-10-30 | 1959-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-04-30 | 1962-10-30 | 1963-05-01 | $7700.00 | Window Closed / Lapsed |