US2863520A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Loudspeaker cone rim treatment
Assignee: General Dynamics Corp
•
Filing: 1955-03-11
•
Granted: 1958-12-09
•
Expires: 1975-03-11
Abstract
No abstract record available.
Inventors
- 👤 Fred A Manley
- 👤 Paul W Ankerman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:17
CPC Classifications
H; H04; H04R; H04R7/00; H04R7/16; H04R7/18; H04R7/20; H04R2307/00; H04R2307/201
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2734591A
Cited
GB237699A
Cited
DE534412C
Cited
GB293414A
Cited
GB320802A
Cited
GB596893A
Cited
US2549091A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-12-08 | 1962-06-09 | 1962-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-12-08 | 1966-06-09 | 1966-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-12-08 | 1970-06-09 | 1970-12-09 | $7700.00 | Window Closed / Lapsed |