Patent US2887000A successfully refreshed from Google Patents.
US2887000A
Expired / Lapsed
US
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Multiple channel speaker system
Assignee: Individual
•
Filing: 1955-07-05
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Granted: 1959-05-19
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Expires: 1975-07-05
Abstract
No abstract record available.
Inventors
- 👤 Donald J Leslie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:06
CPC Classifications
G; G10; G10H; G10H1/00; G10H1/02; G10H1/04; G10H1/043; G10H1/047
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1877317A
Cited
US2491674A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-05-18 | 1962-11-17 | 1963-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-05-18 | 1966-11-17 | 1967-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-05-18 | 1970-11-17 | 1971-05-19 | $7700.00 | Window Closed / Lapsed |