Patent US2540328A successfully refreshed from Google Patents.
US2540328A
Expired / Lapsed
US
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Variable flow pump
Assignee: Individual
•
Filing: 1947-06-13
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Granted: 1951-02-06
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Expires: 1967-06-13
Abstract
No abstract record available.
Inventors
- 👤 Charles B Gray
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:18
CPC Classifications
F; F04; F04B; F04B1/00; F04B1/12; F04B1/26; F04B1/28; F01; F01B; F01B3/00; F01B3/04; F04B1/04; F04B1/06; F04B1/122; F04B1/124; F04B1/14; F04B49/00; F04B49/12; F04B49/121
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US1731145A
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US1934758A
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US1933081A
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US2123815A
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US2107079A
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US2283242A
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US2344565A
Cited
US2370506A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-02-05 | 1954-08-07 | 1955-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-02-05 | 1958-08-07 | 1959-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-02-05 | 1962-08-07 | 1963-02-06 | $7700.00 | Window Closed / Lapsed |