US4087987A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Defrost pressure control system
Assignee: General Electric Co
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Filing: 1976-10-06
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Granted: 1978-05-09
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Expires: 1996-10-06
Abstract
Abstract The defrost pressure control system for a refrigerator includes a reservoir connected in communication with the evaporator of the refrigerating system. The reservoir is placed in heat exchange relationship with a portion of the refrigerator which remains at a relatively low temperature during defrosting so that a portion of the refrigerant in the system condenses in the reservoir during defrosting, thereby being effectively removed from the refrigerating system. A suitable heat sink may also be employed in the heat exchange relationship with the reservoir. Because of withdrawal of the aforementioned refrigerant, the pressure in the refrigerating system at the end of the defrosting operation is substantially below that which would otherwise be present. As a result the torque required to start the compressor is significantly reduced, thereby insuring effective starting of the compressor even when driven by an electric motor having a relatively low starting torque. As soon as the compressor resumes operation, the pressure in the evaporator is substantially reduced to a level well below that in the reservoir and the liquid refrigerant in the reservoir partially vaporizes and all the refrigerant in the reservoir, both gas and liquid, is returned promptly to the refrigerating system, insuring effective normal operation of the refrigerating system.
Inventors
- 👤 Frank A. Schumacher
- 👤 John E. Sterling
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:03
CPC Classifications
F; F25; F25D; F25D21/00; F25D21/002
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
142 words
In a refrigerator system including a compressor, condenser and evaporator connected in series, and a heater for defrosting the evaporator as required, the compressor not running during a defrosting operation, a defrost pressure control system comprising: (a) a reservoir for receiving a portion of the refrigerant employed in said refrigerating system; and (b) means connecting said reservoir in communication with said refrigerating system in the region of said evaporator; (c) said reservoir being positioned in heat exchange relationship with a region which remains relatively cold during defrosting for causing a portion of the refrigerant to condense is said reservoir during defrosting; and (d) condensed refrigerant in said reservoir being caused to be partially vaporized and to be returned to said refrigerating system as both gas and liquid when said compressor is started and reduces pressure in said evaporator after termination of defrosting.
Claim 2
Dependent Claim
142 words
In a refrigerator system including a compressor, condenser and evaporator connected in series, and a heater for defrosting the evaporator as required, the compressor not running during a defrosting operation, a defrost pressure control system comprising: (a) a reservoir for receiving a portion of the refrigerant employed in said refrigerating system; and (b) means connecting said reservoir in communication with said refrigerating system in the region of said evaporator; (c) said reservoir being positioned in heat exchange relationship with a region which remains relatively cold during defrosting for causing a portion of the refrigerant to condense is said reservoir during defrosting; and (d) condensed refrigerant in said reservoir being caused to be partially vaporized and to be returned to said refrigerating system as both gas and liquid when said compressor is started and reduces pressure in said evaporator after termination of defrosting.
Claim 3
Dependent Claim
39 words
The defrost pressure control system of claim 1, wherein said reservoir is positioned above the level of said evaporator and further including means for preventing return flow of condensed refrigerant from said reservoir to said refrigerating system during defrosting.
Claim 4
Dependent Claim
25 words
The defrost pressure control system of claim 2, wherein said means for preventing return flow of condensed refrigerant comprises a restrictor in said connecting means.
Claim 5
Dependent Claim
25 words
The defrost pressure control system of claim 2, wherein said means for preventing return flow of condensed refrigerant comprises a trap in said connecting means.
Claim 6
Dependent Claim
42 words
The defrost pressure control system of claim 2, wherein said means for preventing return flow of condensed refrigerant comprises a gooseneck in said connecting means, said gooseneck extending to a level corresponding approximately to the level of the top of said reservoir.
Claim 7
Dependent Claim
38 words
The defrost pressure control system of claim 1, wherein said liquid refrigerant from said reservoir provides prompt cooling of said evaporator before liquid refrigerant can be supplied to the said evaporator by said compressor after termination of defrosting.
Claim 8
Dependent Claim
23 words
The defrost pressure control system of claim 1, wherein said connecting means is connected to said evaporator intermediate the ends of said evaporator.
Claim 9
Dependent Claim
44 words
The defrost pressure control system of claim 1, and further including a heat sink positioned in heat exchange relationship with said reservoir to insure that said reservoir remains at a sufficiently low temperature throughout defrosting to prevent vaporization of said condensed refrigerant during defrosting.
Claim 10
Dependent Claim
151 words
In a refrigerator including a fresh food compartment and a freezer compartment and including a refrigerating system comprising a compressor, condenser and evaporator in series, and a heater for defrosting the evaporator as required, the compressor not running during a defrosting operation, a defrost control system comprising: (a) a reservoir for receiving a portion of the refrigerant employed in said refrigerating system; and (b) means connecting said reservoir in communication with said refrigerating system in the region of said evaporator; (c) said reservoir being positioned in heat exchange relationship with a wall of said freezer compartment for causing a portion of the refrigerant to condense in said reservoir during defrosting; and (d) condensed refrigerant in said reservoir being caused to be partially vaporized and to be returned to said refrigerating system as both gas and liquid when said compressor is started and reduces pressure in said evaporator after termination of defrosting.
Claim 11
Dependent Claim
151 words
In a refrigerator including a fresh food compartment and a freezer compartment and including a refrigerating system comprising a compressor, condenser and evaporator in series, and a heater for defrosting the evaporator as required, the compressor not running during a defrosting operation, a defrost control system comprising: (a) a reservoir for receiving a portion of the refrigerant employed in said refrigerating system; and (b) means connecting said reservoir in communication with said refrigerating system in the region of said evaporator; (c) said reservoir being positioned in heat exchange relationship with a wall of said freezer compartment for causing a portion of the refrigerant to condense in said reservoir during defrosting; and (d) condensed refrigerant in said reservoir being caused to be partially vaporized and to be returned to said refrigerating system as both gas and liquid when said compressor is started and reduces pressure in said evaporator after termination of defrosting.
Claim 12
Dependent Claim
39 words
The defrost pressure control system of claim 9, wherein said reservoir is positioned above the level of said evaporator, and further including means for preventing return flow of condensed refrigerant from said reservoir to said refrigerating system during defrosting.
Claim 13
Dependent Claim
47 words
The defrost pressure control system of claim 9, and further including a heat sink secured to said wall in heat exchange relationship with said reservoir to insure that said reservoir remains at a sufficiently low temperature throughout defrosting to prevent vaporization of said condensed refrigerant during defrosting.
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) | 1981-05-08 | 1981-11-07 | 1982-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-08 | 1985-11-07 | 1986-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-08 | 1989-11-07 | 1990-05-09 | $7700.00 | Window Closed / Lapsed |