US3230633A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Freeze drying apparatus and method
Assignee: Pennwalt Corp
•
Filing: 1961-10-27
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Granted: 1966-01-25
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Expires: 1981-10-27
Abstract
No abstract record available.
Inventors
- 👤 William H Hamilton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:13
CPC Classifications
F; F26; F26B; F26B5/00; F26B5/04; F26B5/06
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
93 words
A METHOD OF DRYING ARTICLES COMPRISING PLACING ARTICLES IN A CHAMBER, EVACUATING SAID CHAMBER TO A FIRST PRESSURE WHILE ELEVATING THE TEMPERATURE IN SAID CHAMBER, MAINTAINING SAID CHAMBER AT SAID TEMPERATURE AND PRESSURE FOR A PORTION OF THE DRYING CYCLE UNTIL A SUBSTANTIAL AMOUNT OF MOISTURE HAS BEEN REMOVED FROM SAID ARTICLES, THEN INCREASING THE PRESSURE IN SAID CHAMBER TO A PRESSURE ABOVE SAID FIRST PRESSURE WHILE DECREASING THE TEMPERATURE OF THE ARTICLE, AND COMPLETING THE DRYING CYCLE AT A PRESSURE ABOVE SAID FIRST PRESSURE AND AT A TEMPERATURE BELOW SAID FIRST-MENTIONED TEMPERATURE.
References Cited (Backward Citations)
US1799248A
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US1866346A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-01-24 | 1969-07-26 | 1970-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-01-24 | 1973-07-26 | 1974-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-01-24 | 1977-07-26 | 1978-01-25 | $7700.00 | Window Closed / Lapsed |