Patent US3203350A successfully refreshed from Google Patents.
US3203350A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Helical multiple pump
Assignee: Robbins and Myers Inc
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Filing: 1962-11-05
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Granted: 1965-08-31
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Expires: 1982-11-05
Abstract
No abstract record available.
Inventors
- 👤 Sheldon S L Chang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:04
CPC Classifications
F; F04; F04C; F04C2/00; F04C2/08; F04C2/10; F04C2/107; F04C2/1071; F04C2/1073
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
151 words
A MULTIPLE PUMP COMPRISING A CASING HAVING AN INLET AND AN OUTLET AND COMPRISING TWO OUTER HELICAL SCREW ELEMENTS IN AXIALLY SPACED RELATION, AND TWO INNER HELICAL SCREW ELEMENTS IN ENGAGEMENT THEREWITH RESPECTIVELY, EACH OF SAID OUTER ELEMENTS HAVING OINE MORE THREAD RESPECTIVELY THAN THE INNER ELEMENT ENGAGED THEREWITH, THE THREADS OF ONE ENGAGING SET OF INNER AND OUTER ELEMENTS BEING OF OPPOSITE HAND FROM THE THREADS OF THE OTHER SET OF INNER AND OUTER ELEMENT, SAID INNER ELEMENTS BEING FIXED TOGETHER COAXIALLY TO CONSTITUTE A COMMON ROTOR, ONE OF SAID OUTER ELEMENTS BEING FIXED IN SAID CASING, AND THE OTHER OF SAID OUTER ELEMENTS BEING FREE TO ROTATE IN SIAD CASING TO THE EXTENT PERMITTED BY INTERFERENCE WITHH THE INNER ELEMENT, WHEREBY IT IS SELF-ALIGNING AS TO PHASE WITH RESPECT TO THE INNER ELEMENT ENGAGED THEREIN AND SAID TWO SETS OF INNER AND OUTER ELEMENTS MAY COACT PUMPINGL WITHOUT BINDING.
Claim 2
Dependent Claim
151 words
A MULTIPLE PUMP COMPRISING A CASING HAVING AN INLET AND AN OUTLET AND COMPRISING TWO OUTER HELICAL SCREW ELEMENTS IN AXIALLY SPACED RELATION, AND TWO INNER HELICAL SCREW ELEMENTS IN ENGAGEMENT THEREWITH RESPECTIVELY, EACH OF SAID OUTER ELEMENTS HAVING OINE MORE THREAD RESPECTIVELY THAN THE INNER ELEMENT ENGAGED THEREWITH, THE THREADS OF ONE ENGAGING SET OF INNER AND OUTER ELEMENTS BEING OF OPPOSITE HAND FROM THE THREADS OF THE OTHER SET OF INNER AND OUTER ELEMENT, SAID INNER ELEMENTS BEING FIXED TOGETHER COAXIALLY TO CONSTITUTE A COMMON ROTOR, ONE OF SAID OUTER ELEMENTS BEING FIXED IN SAID CASING, AND THE OTHER OF SAID OUTER ELEMENTS BEING FREE TO ROTATE IN SIAD CASING TO THE EXTENT PERMITTED BY INTERFERENCE WITHH THE INNER ELEMENT, WHEREBY IT IS SELF-ALIGNING AS TO PHASE WITH RESPECT TO THE INNER ELEMENT ENGAGED THEREIN AND SAID TWO SETS OF INNER AND OUTER ELEMENTS MAY COACT PUMPINGL WITHOUT BINDING.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-08-30 | 1969-03-01 | 1969-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-08-30 | 1973-03-01 | 1973-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-08-30 | 1977-03-01 | 1977-08-31 | $7700.00 | Window Closed / Lapsed |