US2853557A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sound distribution system
Assignee: DICTOGRAPH PRODUCTS CO Inc
•
Filing: 1955-01-28
•
Granted: 1958-09-23
•
Expires: 1975-01-28
Abstract
No abstract record available.
Inventors
- 👤 Frank H Lehman
- 👤 Philip N Lehr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:56
CPC Classifications
H; H04; H04B; H04B5/00; H04B5/20; H04B5/24; H04B5/26
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2252641A
Cited
GB495171A
Cited
US2567431A
Cited
US2530621A
Cited
US2721896A
Cited
FR1071308A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-09-22 | 1962-03-24 | 1962-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-09-22 | 1966-03-24 | 1966-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-09-22 | 1970-03-24 | 1970-09-23 | $7700.00 | Window Closed / Lapsed |