Patent US2569918A successfully refreshed from Google Patents.
US2569918A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microfilm projector
Assignee: Individual
•
Filing: 1946-01-22
•
Granted: 1951-10-02
•
Expires: 1966-01-22
Abstract
No abstract record available.
Inventors
- 👤 Berggren Per Johan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:47
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/10; G03B21/11; G03B21/111
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1160764A
Cited
US1287502A
Cited
US1427575A
Cited
US1581198A
Cited
US1671449A
Cited
US2022903A
Cited
US1824519A
Cited
US1964712A
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US2008982A
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US2064368A
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US2160847A
Cited
US2160848A
Cited
US2174778A
Cited
US2242464A
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US2174660A
Cited
US2323372A
Cited
US2292966A
Cited
US2351371A
Cited
US2322023A
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US2377476A
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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) | 1954-10-01 | 1955-04-02 | 1955-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-10-01 | 1959-04-02 | 1959-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-10-01 | 1963-04-02 | 1963-10-02 | $7700.00 | Window Closed / Lapsed |