Patent US3444487A successfully refreshed from Google Patents.
US3444487A
Expired / Lapsed
US
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Waveguide having corrugated exterior and smooth metal coated interior
Assignee: Telefunken Patentverwertungs GmbH
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Filing: 1966-10-03
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Granted: 1969-05-13
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Expires: 1986-10-03
Abstract
No abstract record available.
Inventors
- 👤 Wolfgang Krank
- 👤 Gerhard Schickle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:27
CPC Classifications
H; H01; H01P; H01P3/00; H01P3/12; H01P3/14
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
CA557003A
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GB739488A
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US2758612A
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US2908746A
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US3101458A
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US3016502A
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US3101744A
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DE1193125B
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US3299374A
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US3290762A
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US3364446A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-05-12 | 1972-11-11 | 1973-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-05-12 | 1976-11-11 | 1977-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-05-12 | 1980-11-11 | 1981-05-13 | $7700.00 | Window Closed / Lapsed |