Patent US3899897A successfully refreshed from Google Patents.
US3899897A
Expired / Lapsed
US
⏱️ 0.0 years remaining
By-pass suction throttling valve in a refrigeration system
Assignee: Ford Motor Co
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Filing: 1974-04-03
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Granted: 1975-08-19
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Expires: 1994-04-03
Abstract
Abstract An air conditioning system adapted especially for use in automotive vehicles comprising a refrigerant compressor, a condenser and an evaporator situated in a closed air conditioning cycle wherein a thermal expansion valve is located in the refrigerant flow line connecting the condenser with the evaporator for throttling refrigerant flow from a high pressure at the condenser outlet to a lower pressure at the evaporator inlet and wherein a suction throttling valve is located between the evaporator outlet and the compressor inlet for controlling the evaporator outlet pressure under low evaporator load conditions, the thermal expansion valve responding to the pressure differential across the suction throttling valve, and means for modifying the pressure difference between the evaporator outlet and the compressor inlet under low load conditions thereby reducing the compressor power consumption for low load operating conditions while obtaining satisfactory compressor lubrication, reduced compressor noise and increased compressor durability.
Inventors
- 👤 David H Boerger
- 👤 Jr Allen D Krugler
- 👤 Donald A Willoughby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:15
CPC Classifications
F; F25; F25B; F25B41/00; F25B41/20; F25B41/22; F25B41/30; F25B41/31; F25B41/325; F25B41/33; F25B41/335; F25B2341/00; F25B2341/06; F25B2341/068; F25B2341/0683
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
208 words
An air conditioning system comprising a fluid refrigerant in a closed circuit, said circuit including a compressor, a condenser and an evaporator located in series relationship, a thermal expansion valve in the circuit between the condenser outlet and the evaporator inlet, a suction throttling device located between the evaporator outlet and the compressor inlet, said thermal expansion valve comprising a variable flow restriction and a valve means for controlling the degree of restriction to refrigerant flow, said suction throttling device including a refrigerant flow restriction and valve means for controlling the flow through said restriction whereby the pressure differential across the suction throttling device for any given pressure on the outlet side of the evaporator is greater at low evaporator outlet pressures than at high evaporator outlet pressure, a controlled bypass flow passage from a point downstream of the thermal expansion valve to a point downstream of the suction throttling device including flow restricting means therein for determining the effective signal pressure in said bypass passage, said thermal expansion valve means including means responding to the temperature at the outlet of the evaporator and including means responding to the signal pressure in said bypass passage to vary the degree of flow restriction for the refrigerant entering the evaporator.
Claim 2
Dependent Claim
208 words
An air conditioning system comprising a fluid refrigerant in a closed circuit, said circuit including a compressor, a condenser and an evaporator located in series relationship, a thermal expansion valve in the circuit between the condenser outlet and the evaporator inlet, a suction throttling device located between the evaporator outlet and the compressor inlet, said thermal expansion valve comprising a variable flow restriction and a valve means for controlling the degree of restriction to refrigerant flow, said suction throttling device including a refrigerant flow restriction and valve means for controlling the flow through said restriction whereby the pressure differential across the suction throttling device for any given pressure on the outlet side of the evaporator is greater at low evaporator outlet pressures than at high evaporator outlet pressure, a controlled bypass flow passage from a point downstream of the thermal expansion valve to a point downstream of the suction throttling device including flow restricting means therein for determining the effective signal pressure in said bypass passage, said thermal expansion valve means including means responding to the temperature at the outlet of the evaporator and including means responding to the signal pressure in said bypass passage to vary the degree of flow restriction for the refrigerant entering the evaporator.
Claim 3
Dependent Claim
198 words
An air conditioning system comprising a fluid refrigerant in a closed circuit, said circuit including a compressor, a condenser and an evaporator located in series relationship, a thermal expansion valve in the circuit between the condenser outlet and the evaporator inlet, a suction throttling device located between the evaporator outlet and the compressor inlet, said thermal expansion valve comprisng a variable flow restriction and a valve means for contrOlling the degree of restriction of refrigerant flow, said suction throttling device including a refrigerant flow restriction and valve means for controlling the flow through said restriction whereby the pressure differential across the suction throttling device for any given pressure on the outlet side of the evaporator is greater at low evaporator outlet pressures than at higher evaporator outlet pressures, a controlled bypass flow passage around the evaporator and the suction throttling device including flow restricting means therein for determining the effective signal pressure in said bypass passage, said thermal expansion valve means including means responding to the temperature at the outlet of the evaporator and including means responding to the signal pressure in said bypass passage to vary the degree of flow restriction for the refrigerant entering the evaporator.
Claim 4
Dependent Claim
198 words
An air conditioning system comprising a fluid refrigerant in a closed circuit, said circuit including a compressor, a condenser and an evaporator located in series relationship, a thermal expansion valve in the circuit between the condenser outlet and the evaporator inlet, a suction throttling device located between the evaporator outlet and the compressor inlet, said thermal expansion valve comprisng a variable flow restriction and a valve means for contrOlling the degree of restriction of refrigerant flow, said suction throttling device including a refrigerant flow restriction and valve means for controlling the flow through said restriction whereby the pressure differential across the suction throttling device for any given pressure on the outlet side of the evaporator is greater at low evaporator outlet pressures than at higher evaporator outlet pressures, a controlled bypass flow passage around the evaporator and the suction throttling device including flow restricting means therein for determining the effective signal pressure in said bypass passage, said thermal expansion valve means including means responding to the temperature at the outlet of the evaporator and including means responding to the signal pressure in said bypass passage to vary the degree of flow restriction for the refrigerant entering the evaporator.
Claim 5
Dependent Claim
149 words
An air conditioning system having fluid refrigerant in a closed circuit, said circuit including a compressor, a condenser and an evaporator located in fluid-flow series relationship, a thermal expansion valve located in said circuit between the outlet of the condenser and the inlet of the evaporator, said thermal expansion valve including a variable flow restricting valve, a suction throttling device between the evaporator outlet and the compressor inlet for establishing a pressure drop in the refrigerant flow path that is higher at low evaporator outlet pressures than at higher evaporator outlet pressures, a bypass flow passage around the suction throttling device, means for controlling the rate of flow of refrigerant through said bypass passage, and control means responsive to the pressure at the bypass passage and to the temperature of said evaporator to control the degree of restriction of said thermal expansion valve to the flow of refrigerant therethrough.
Claim 6
Dependent Claim
149 words
An air conditioning system having fluid refrigerant in a closed circuit, said circuit including a compressor, a condenser and an evaporator located in fluid-flow series relationship, a thermal expansion valve located in said circuit between the outlet of the condenser and the inlet of the evaporator, said thermal expansion valve including a variable flow restricting valve, a suction throttling device between the evaporator outlet and the compressor inlet for establishing a pressure drop in the refrigerant flow path that is higher at low evaporator outlet pressures than at higher evaporator outlet pressures, a bypass flow passage around the suction throttling device, means for controlling the rate of flow of refrigerant through said bypass passage, and control means responsive to the pressure at the bypass passage and to the temperature of said evaporator to control the degree of restriction of said thermal expansion valve to the flow of refrigerant therethrough.
Claim 7
Dependent Claim
62 words
The combination set forth in claim 1 wherein said bypass passage has a pair of calibrated flow-restrictions therein for establishing a pilot pressure zone between the orifices upon flow of fluid from the inlet side of the suction throttling device to the outlet side thereof through said bypass passage, said pilot pressure zone being in fluid communication with said thermal expansion valve.
Claim 8
Dependent Claim
62 words
The combination set forth in claim 2 wherein said bypass passage has a pair of calibrated flow-restrictions therein for establishing a pilot pressure zone between the orifices upon flow of fluid from the inlet side of the suction throttling device to the outlet side thereof through said bypass passage, said pilot pressure zone being in fluid communication with said thermal expansion valve.
Claim 9
Dependent Claim
62 words
The combination set forth in claim 3 wherein said bypass passage has a pair of calibrated flow-restrictions therein for establishing a pilot pressure zone between the orifices upon flow of fluid from the inlet side of the suction throttling device to the outlet side thereof through said bypass passage, said pilot pressure zone being in fluid communication with said thermal expansion valve.
References Cited (Backward Citations)
US3365905A
Cited
US3810366A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-18 | 1979-02-17 | 1979-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-18 | 1983-02-17 | 1983-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-18 | 1987-02-17 | 1987-08-19 | $7700.00 | Window Closed / Lapsed |