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US2856542A
Expired / Lapsed
US
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Apparatus for preventing the entry of foreign matter in photoelectric cell unit
Assignee: Individual
•
Filing: 1954-12-02
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Granted: 1958-10-14
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Expires: 1974-12-02
Abstract
No abstract record available.
Inventors
- 👤 Mcpheeters August Earnest
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:59
CPC Classifications
H; H01; H01J; H01J40/00; H01J40/16
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) | 1961-10-13 | 1962-04-14 | 1962-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-10-13 | 1966-04-14 | 1966-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-10-13 | 1970-04-14 | 1970-10-14 | $7700.00 | Window Closed / Lapsed |