US3564727A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Freeze dryer using an expendable refrigerant
Assignee: Virtis Co Inc
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Filing: 1969-03-03
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Granted: 1971-02-23
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Expires: 1989-03-03
Abstract
Abstract A FREEZE DRYING ARRANGEMENT HAVING MEAS TO PERMIT THE USE OF AN EXPENDABLE REFRIGERANT. A TRANSPARENT DOOR IS ALSO DISCLOSED HAVING A METALLIC LAYER THEREON TO PERMIT VIEWING THERETHROUGH WHILE REFLECTING RADIANT ENERGY WHICH COULD AFFECT THE TEMPERATURE LEVEL IN T HE CHAMBER.
Inventors
- 👤 Douglas S Fraser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:53
CPC Classifications
F; F26; F26B; F26B5/00; F26B5/04; F26B5/06
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) | 1974-02-22 | 1974-08-24 | 1975-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-22 | 1978-08-24 | 1979-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-22 | 1982-08-24 | 1983-02-23 | $7700.00 | Window Closed / Lapsed |