US3520638A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Means and apparatus for sensing and controlling material levels
Assignee: Individual
•
Filing: 1968-04-08
•
Granted: 1970-07-14
•
Expires: 1988-04-08
Abstract
No abstract record available.
Inventors
- 👤 Donald H Mcumber
- 👤 John W Blackgrove
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:36
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/22; G01F23/26; G01F23/263; G05; G05D; G05D9/00; G05D9/12; Y; Y10; Y10T; Y10T137/00; Y10T137/7287; Y10T137/7306
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3010319A
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US2623928A
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US2672880A
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US2919579A
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US3131314A
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US3136871A
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US3213360A
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US3277711A
Cited
US3285181A
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US3392581A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-07-13 | 1974-01-12 | 1974-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-13 | 1978-01-12 | 1978-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-13 | 1982-01-12 | 1982-07-14 | $7700.00 | Window Closed / Lapsed |