Patent US1646818A successfully refreshed from Google Patents.
US3552136A
Expired / Lapsed
US
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Safety control for water chillers
Assignee: Robertshaw US Holding Corp
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Filing: 1968-12-19
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Granted: 1971-01-05
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Expires: 1988-12-19
Abstract
Abstract A WATER CHILLING MACHINE, HAVING A WATER FREEZING UNIT IN A CHAMBER THROUGH WHICH WATER TO BE CHILLED IS CIRCULATED BY A PUMP, IS SHUT DOWN TO DISCONTINUE FREEZING UNIT OPERATION WHEN THE PRESSURE DIFFERENTIAL BETWEEN THE INLET AND OUTLET OF THE PUMP IS BELOW A GIVEN DEGREE, WHICH MAY OCCUR DUE TO LACK OF WATER, CLOGGING OF WATER CONDUITS, ETC., AND ALSO WHEN THAT DIFFERENTIAL INCREASES TO A PREDETERMINED DEGREE OVER NORMAL, WHICH OF ICE OCCURS IN THE CHAMBER.
Inventors
- 👤 Russell E Cook
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:35
CPC Classifications
F; F25; F25D; F25D31/00; F25D31/002; F25D31/003; F25D21/00; F25D21/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-04 | 1974-07-06 | 1975-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-04 | 1978-07-06 | 1979-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-04 | 1982-07-06 | 1983-01-05 | $7700.00 | Window Closed / Lapsed |