Patent US3859815A successfully refreshed from Google Patents.
US3859815A
Expired / Lapsed
US
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Two-stage compression apparatus
Assignee: Mayekawa Manufacturing Co
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Filing: 1974-03-07
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Granted: 1975-01-14
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Expires: 1994-03-07
Abstract
Abstract Two-stage compression apparatus comprises a first compressor for low compression stage and a second compressor for high compression stage. Each of the compressors is composed of a screw compressor of an oil injection type. A single electric motor is provided for driving both compressors. The motor is enclosed within a confined atmosphere which is on the one hand communicated with the exhaust side of the first compressor and on the other hand communicated with the suction side of the second compressor.
Inventors
- 👤 Keisuke Kasahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:04
CPC Classifications
F; F25; F25B; F25B31/00; F25B31/006; F25B1/00; F25B1/10; F25B2400/00; F25B2400/13; F25B2600/00; F25B2600/25; F25B2600/2509
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
76 words
Two-stage compression apparatus comprising an oil injection type of a screw compressor for low compression stage, an oil injection type of a screw compressor for high compression stage, an electric motor for driving both of said compressors, and means for defining a sealed atmosphere around said electric motor, said atmosphere being communicated with a gas exhaust outlet of said compressor for low compression stage and a gas suction inlet of said compressor for high compression stage.
Claim 2
Dependent Claim
76 words
Two-stage compression apparatus comprising an oil injection type of a screw compressor for low compression stage, an oil injection type of a screw compressor for high compression stage, an electric motor for driving both of said compressors, and means for defining a sealed atmosphere around said electric motor, said atmosphere being communicated with a gas exhaust outlet of said compressor for low compression stage and a gas suction inlet of said compressor for high compression stage.
Claim 3
Dependent Claim
47 words
Two-stage compression apparatus as set forth in claim 1, wherein said atmosphere is communicated with a portion of a liquid gas conduit through a temperature responsive expansion valve which is operated in dependence upon variations in temperature of exhaust gas from said compressor for high compression stage.
Claim 4
Dependent Claim
22 words
Two-stage compression apparatus as set forth in claim 2, further comprising a supercooler disposed between said sealed atmosphere and said expansion valve.
Claim 5
Dependent Claim
24 words
Two-stage compression apparatus as set forth in claim 1, wherein said means for defining a sealed atmosphere is formed by a fluid-tightly closed enclosure.
Claim 6
Dependent Claim
32 words
Two-stage compression apparatus as set forth in claim 1, wherein said means for defining a sealed atmosphere is formed by a jacket provided around the periphery of the housing of said motor.
Claim 7
Dependent Claim
26 words
Two-stage compression apparatus as set forth in claim 1, wherein said compressors for low and high compression stages are coaxially arranged with interposition of said motor.
Claim 8
Dependent Claim
17 words
Two-stage compression apparatus as set forth in claim 1, wherein said motor has a single output shaft.
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) | 1978-01-13 | 1978-07-15 | 1979-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-13 | 1982-07-15 | 1983-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-13 | 1986-07-15 | 1987-01-14 | $7700.00 | Window Closed / Lapsed |