US2931862A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sound reproduction system
Assignee: US Philips Corp
•
Filing: 1957-07-29
•
Granted: 1960-04-05
•
Expires: 1977-07-29
Abstract
No abstract record available.
Inventors
- 👤 Vermeulen Roelof
- 👤 Kleis Derk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:37
CPC Classifications
G; G10; G10K; G10K15/00; G10K15/08; G10K15/10; Y; Y10; Y10S; Y10S84/00; Y10S84/27
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) | 1963-04-05 | 1963-10-05 | 1964-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-04-05 | 1967-10-05 | 1968-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-04-05 | 1971-10-05 | 1972-04-05 | $7700.00 | Window Closed / Lapsed |