US2730869A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purging device for closed refrigeration systems
Assignee: Servel Inc
•
Filing: 1952-01-08
•
Granted: 1956-01-17
•
Expires: 1972-01-08
Abstract
No abstract record available.
Inventors
- 👤 Edward M Stubblefield
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:48
CPC Classifications
F; F25; F25B; F25B43/00; F25B43/04; F25B43/046
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1174631A
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US1685759A
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US1738720A
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GB308792A
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GB358086A
Cited
US1964391A
Cited
US2320349A
Cited
US2374564A
Cited
US2536610A
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US2456163A
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US2627933A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-01-16 | 1959-07-18 | 1960-01-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-01-16 | 1963-07-18 | 1964-01-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-01-16 | 1967-07-18 | 1968-01-17 | $7700.00 | Window Closed / Lapsed |