US2871971A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sound-propagating device
Assignee: Individual
•
Filing: 1954-04-28
•
Granted: 1959-02-03
•
Expires: 1974-04-28
Abstract
No abstract record available.
Inventors
- 👤 Robert J Beecroft
- 👤 Edward N Fenton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:22
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R1/28; H04R1/2807; H04R1/2811
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-02-02 | 1962-08-04 | 1963-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-02-02 | 1966-08-04 | 1967-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-02-02 | 1970-08-04 | 1971-02-03 | $7700.00 | Window Closed / Lapsed |