Patent US3265293A successfully refreshed from Google Patents.
US3265293A
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Vacuum pump of the screw rotor type and method for operating the same
Assignee: Svenska Rotor Maskiner AB
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Filing: 1966-01-10
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Granted: 1966-08-09
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Expires: 1986-01-10
Abstract
No abstract record available.
Inventors
- 👤 Schibbye Lauritz Benedictus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:26
CPC Classifications
F; F04; F04C; F04C18/00; F04C18/08; F04C18/12; F04C18/14; F04C18/16; F04C23/00; F04C23/001; F04C27/00; F04C27/008; F04C27/009; F04C29/00; F04C29/0007
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
111 words
A MULTIPLE STAGE VACUUM PUMP FOR COMPRESSING AN ELASTIC FLUID FROM A SUB-ATMOSPHERIC INLET PRESSURE TO A DELIVERY PRESSURE FOR DISCHARGE TO AMBIENT ATMOSPHERE, COMPRISING A MAIN COMPRESSION STAGE OF THE HELICAL SCREW ROTOR TYPE HAVING INTERMESHING MALE AND FEMALE ROTORS PROVIDING APOSITIVE SEALING AND FURTHER COMPRISING A PRECOMPRESSION STAGE FOR PRE-COMPRESSING SAID FLUID FROM SAID INLET PRESSURE AND DELIVERING IT AT AN INTERMEDIATE PRESSURE TO SAID MAIN COMPRESSION STAGE, SAID PRE-COMPRESSION STAGE HAVING A PRESSURE RATIO NOT EXCEEDING 5 TO 1 AND OPERATING TO EFFECT A PRESSURE RISE IN SAID PRE-COMPRESSION STAGE NOT IN EXCESS OF 15% OF THE TOTAL PRESSURE RISE FROM SAID INLET PRESSURE TO SAID DELIVERY PRESSURE.
Claim 2
Dependent Claim
111 words
A MULTIPLE STAGE VACUUM PUMP FOR COMPRESSING AN ELASTIC FLUID FROM A SUB-ATMOSPHERIC INLET PRESSURE TO A DELIVERY PRESSURE FOR DISCHARGE TO AMBIENT ATMOSPHERE, COMPRISING A MAIN COMPRESSION STAGE OF THE HELICAL SCREW ROTOR TYPE HAVING INTERMESHING MALE AND FEMALE ROTORS PROVIDING APOSITIVE SEALING AND FURTHER COMPRISING A PRECOMPRESSION STAGE FOR PRE-COMPRESSING SAID FLUID FROM SAID INLET PRESSURE AND DELIVERING IT AT AN INTERMEDIATE PRESSURE TO SAID MAIN COMPRESSION STAGE, SAID PRE-COMPRESSION STAGE HAVING A PRESSURE RATIO NOT EXCEEDING 5 TO 1 AND OPERATING TO EFFECT A PRESSURE RISE IN SAID PRE-COMPRESSION STAGE NOT IN EXCESS OF 15% OF THE TOTAL PRESSURE RISE FROM SAID INLET PRESSURE TO SAID DELIVERY PRESSURE.
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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) | 1969-08-08 | 1970-02-07 | 1970-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-08-08 | 1974-02-07 | 1974-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-08-08 | 1978-02-07 | 1978-08-09 | $7700.00 | Window Closed / Lapsed |