US2694462A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acoustic system for loud-speakers
Assignee: Individual
•
Filing: 1951-09-19
•
Granted: 1954-11-16
•
Expires: 1971-09-19
Abstract
No abstract record available.
Inventors
- 👤 Robbins Frank
- 👤 Joseph William
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 02:58
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R1/28; H04R1/2807; H04R1/2838; H04R1/2842; H04R1/26; H04R1/30
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1865735A
Cited
US1912454A
Cited
US1984542A
Cited
US1969704A
Cited
US2193399A
Cited
US2373692A
Cited
FR971128A
Cited
US2604182A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-11-15 | 1958-05-17 | 1958-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-11-15 | 1962-05-17 | 1962-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-11-15 | 1966-05-17 | 1966-11-16 | $7700.00 | Window Closed / Lapsed |