Patent US2820904A successfully refreshed from Google Patents.
US2820904A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Crystal holder
Assignee: US Philips Corp
•
Filing: 1952-10-25
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Granted: 1958-01-21
•
Expires: 1972-10-25
Abstract
No abstract record available.
Inventors
- 👤 Lowitzsch Kurt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:48
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/05; H03H9/0504
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2174809A
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US2213306A
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US2445132A
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US2432913A
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US2585916A
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US2452045A
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US2500926A
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US2573056A
Cited
US2533747A
Cited
US2581219A
Cited
US2602899A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-01-20 | 1961-07-22 | 1962-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-01-20 | 1965-07-22 | 1966-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-01-20 | 1969-07-22 | 1970-01-21 | $7700.00 | Window Closed / Lapsed |