US3431883A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure differential indicator for filters
Assignee: Marvel Engineering Co
•
Filing: 1965-02-19
•
Granted: 1969-03-11
•
Expires: 1985-02-19
Abstract
No abstract record available.
Inventors
- 👤 Walter J Kudlaty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:31
CPC Classifications
B; B01; B01D; B01D35/00; B01D35/14; B01D35/143; G; G01; G01L; G01L7/00; G01L7/16
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1187693A
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US2574866A
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US2803713A
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US2916205A
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US3203245A
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US3145570A
Cited
US3182630A
Cited
US3325010A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-03-10 | 1972-09-09 | 1973-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-03-10 | 1976-09-09 | 1977-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-03-10 | 1980-09-09 | 1981-03-11 | $7700.00 | Window Closed / Lapsed |