US2846520A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low frequency loudspeaker
Assignee: Individual
•
Filing: 1955-11-22
•
Granted: 1958-08-05
•
Expires: 1975-11-22
Abstract
No abstract record available.
Inventors
- 👤 Philip J Brownscombe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:49
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/42
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1730528A
Cited
US2713396A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-08-04 | 1962-02-03 | 1962-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-08-04 | 1966-02-03 | 1966-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-08-04 | 1970-02-03 | 1970-08-05 | $7700.00 | Window Closed / Lapsed |