US2691072A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite magnetic recording tape
Assignee: AT&T Inc
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Filing: 1949-04-01
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Granted: 1954-10-05
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Expires: 1969-04-01
Abstract
No abstract record available.
Inventors
- 👤 Robert C Mathes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:31
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/66; G11B5/672; G11B5/02; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/923; Y10S428/924; Y10S428/926; Y10S428/9265; Y10S428/928; Y10S428/9335; Y10S428/934; Y10S428/935; Y10S428/938; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12771; Y10T428/12861; Y10T428/12951; Y10T428/12958
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) | 1957-10-04 | 1958-04-05 | 1958-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-10-04 | 1962-04-05 | 1962-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-10-04 | 1966-04-05 | 1966-10-05 | $7700.00 | Window Closed / Lapsed |