US2931308A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plural intermeshing screw structures
Assignee: Improved Machinery Inc
•
Filing: 1957-03-29
•
Granted: 1960-04-05
•
Expires: 1977-03-29
Abstract
No abstract record available.
Inventors
- 👤 Luthi Oscar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:57
CPC Classifications
F; F04; F04C; F04C2/00; F04C2/08; F04C2/082; F04C2/084; F04C13/00; F04C13/001
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
DE413887C
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US2511878A
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DE455967C
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US1698802A
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GB347246A
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US2048286A
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FR789211A
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CH246507A
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GB670396A
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GB716910A
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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) | 1963-04-05 | 1963-10-05 | 1964-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-04-05 | 1967-10-05 | 1968-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-04-05 | 1971-10-05 | 1972-04-05 | $7700.00 | Window Closed / Lapsed |