US3719057A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two-stage refrigeration system having crankcase pressure regulation in high stage compressor
Assignee: Copeland Industrial LP
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Filing: 1971-10-08
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Granted: 1973-03-06
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Expires: 1991-10-08
Abstract
Abstract A two-stage refrigeration system including a condensor, a receiver, an evaporator, a low-stage dry-wall compressor and a high-stage dry-wall compressor, the low-stage compressor including an oil-draining assembly for automatically draining oil from the suction chamber to the crankcase chamber, and a pressure-equalizing connection between the suction chamber and the crankcase chamber, the high-stage compressor having an oildraining assembly for automatically draining oil from the highstage suction chamber to the high-stage crankcase chamber, and a pressure connection between the high-stage crankcase chamber and the low-stage crankcase chamber; and a pressure-responsive regulating valve interposed in the connection between the highstage crankcase chamber and the low-stage crankcase chamber, the pressure-responsive valve being connected to respond to the highstage suction chamber pressure to maintain a predetermined pressure differential of one pound per square inch between the high-stage suction chamber and the high-stage crankcase chamber.
Inventors
- 👤 W Grant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:23
CPC Classifications
F; F25; F25B; F25B1/00; F25B1/10
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
93 words
A refrigeration system comprising, a condenser, a receiver, and an evaporator, a low-stage drywall compressor and a high-stage drywall compressor operatively connected to said condenser, receiver, evaporator and to each other, each compressor including a discharge chamber, a suction chamber and a crankcase chamber, first means for draining oil from said low-stage suction chamber to said low-stage crankcase chamber, second means for automatically draining oil from said high-stage suction chamber to said high-stage crankcase chamber, and means for maintaining a predetermined pressure differential between said high-stage sUction chamber and said high-stage crankcase chamber.
Claim 2
Dependent Claim
93 words
A refrigeration system comprising, a condenser, a receiver, and an evaporator, a low-stage drywall compressor and a high-stage drywall compressor operatively connected to said condenser, receiver, evaporator and to each other, each compressor including a discharge chamber, a suction chamber and a crankcase chamber, first means for draining oil from said low-stage suction chamber to said low-stage crankcase chamber, second means for automatically draining oil from said high-stage suction chamber to said high-stage crankcase chamber, and means for maintaining a predetermined pressure differential between said high-stage sUction chamber and said high-stage crankcase chamber.
Claim 3
Dependent Claim
93 words
A refrigeration system comprising, a condenser, a receiver, and an evaporator, a low-stage drywall compressor and a high-stage drywall compressor operatively connected to said condenser, receiver, evaporator and to each other, each compressor including a discharge chamber, a suction chamber and a crankcase chamber, first means for draining oil from said low-stage suction chamber to said low-stage crankcase chamber, second means for automatically draining oil from said high-stage suction chamber to said high-stage crankcase chamber, and means for maintaining a predetermined pressure differential between said high-stage sUction chamber and said high-stage crankcase chamber.
Claim 4
Dependent Claim
93 words
A refrigeration system comprising, a condenser, a receiver, and an evaporator, a low-stage drywall compressor and a high-stage drywall compressor operatively connected to said condenser, receiver, evaporator and to each other, each compressor including a discharge chamber, a suction chamber and a crankcase chamber, first means for draining oil from said low-stage suction chamber to said low-stage crankcase chamber, second means for automatically draining oil from said high-stage suction chamber to said high-stage crankcase chamber, and means for maintaining a predetermined pressure differential between said high-stage sUction chamber and said high-stage crankcase chamber.
Claim 5
Dependent Claim
34 words
The system according to claim 1 wherein said maintaining means includes a pressure-responsive valve connected to vent said high-stage crankcase chamber and connected to respond to the discharge pressure of said low-stage discharge chamber.
Claim 6
Dependent Claim
27 words
The system according to claim 2 wherein said valve is set to maintain a one-pound pressure differential between the high-stage suction chamber and the high-stage crankcase chamber.
Claim 7
Dependent Claim
70 words
The system according to claim 1 wherein each of said oil-draining means includes a reservoir operatively connected to allow oil to drain from the corresponding suction chamber to the reservoir and from the reservoir to the corresponding crankcase chamber and including means responsive to the level of oil in the reservoir for selectively connecting said reservoir in gas-pressure equalizing relation to one of the corresponding suction chambers or discharge chambers.
Claim 8
Dependent Claim
63 words
The system according to claim 1 including a first gas pressure conduit connected between said high-stage crankcase chamber and said low-stage crankcase chamber, and a second gas pressure conduit connected between said low-stage discharge chamber and said high-stage suction chamber, said maintaining means including a pressure-responsive regulating valve interposed in said first gas pressure conduit and connected to said second gas pressure conduit.
Claim 9
Dependent Claim
29 words
The system according to claim 5 wherein said valve is set to maintain the pressure in said high-stage suction chamber higher than the pressure in said high-stage crankcase chamber.
Claim 10
Dependent Claim
116 words
A refrigeration system having a condenser, a receiver, and an evaporator operatively connected to a first stage drywall compressor including a first stage suction chamber, a first stage discharge chamber and a first stage crankcase chamber, and a second stage drywall compressor including a second stage suction chamber, a second stage discharge chamber, and a second stage crankcase chamber, a gas refrigerant conduit connecting said first stage discharge chamber in gas pressure relation to said second stage suction chamber, a gas pressure conduit connecting said second stage crankcase chamber in gas pressure relation to said low-stage crankcase chamber, and means interposed in said gas pressure conduit for controlling the pressure in said second stage crankcase chamber.
Claim 11
Dependent Claim
116 words
A refrigeration system having a condenser, a receiver, and an evaporator operatively connected to a first stage drywall compressor including a first stage suction chamber, a first stage discharge chamber and a first stage crankcase chamber, and a second stage drywall compressor including a second stage suction chamber, a second stage discharge chamber, and a second stage crankcase chamber, a gas refrigerant conduit connecting said first stage discharge chamber in gas pressure relation to said second stage suction chamber, a gas pressure conduit connecting said second stage crankcase chamber in gas pressure relation to said low-stage crankcase chamber, and means interposed in said gas pressure conduit for controlling the pressure in said second stage crankcase chamber.
Claim 12
Dependent Claim
33 words
The system according to claim 7 wherein said controlling means in connected to said gas refrigerant conduit to maintain a predetermined pressure differential between said second-stage suction chamber and said second-stage crankcase chamber.
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) | 1976-03-05 | 1976-09-04 | 1977-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-05 | 1980-09-04 | 1981-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-05 | 1984-09-04 | 1985-03-06 | $7700.00 | Window Closed / Lapsed |