US3759049A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Defrost control
Assignee: Whirlpool Corp
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Filing: 1972-02-25
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Granted: 1973-09-18
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Expires: 1992-02-25
Abstract
Abstract A refrigeration apparatus having means for automatically controlling cyclical defrosting thereof. The control includes means responsive both to humidity conditions within the apparatus and to time for providing automatically initiation of the defrosting operation as a function of both such parameters.
Inventors
- 👤 P Strauss
- 👤 R Jennison
- 👤 B Jones
- 👤 C Bell
- 👤 R Gwinn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:46
CPC Classifications
F; F25; F25D; F25D21/00; F25D21/002; F25D21/006; F25B; F25B2700/00; F25B2700/02
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
97 words
In a refrigeratiOn apparatus having means defining a chamber to be refrigerated, cooling means for providing refrigerated air within said apparatus to said chamber, and defrosting means for defrosting said cooling means, control means for controlling the operation of said defrosting means comprising: humidity sensing means for sensing the humidity of said air within said apparatus; accumulating means for integrating the amount of humidity sensed by said humidity sensing device with time; and means for initiating a defrosting operation by said defrosting means as a result of a preselected integrated amount of said sensed humidity and time.
Claim 2
Dependent Claim
97 words
In a refrigeratiOn apparatus having means defining a chamber to be refrigerated, cooling means for providing refrigerated air within said apparatus to said chamber, and defrosting means for defrosting said cooling means, control means for controlling the operation of said defrosting means comprising: humidity sensing means for sensing the humidity of said air within said apparatus; accumulating means for integrating the amount of humidity sensed by said humidity sensing device with time; and means for initiating a defrosting operation by said defrosting means as a result of a preselected integrated amount of said sensed humidity and time.
Claim 3
Dependent Claim
20 words
The refrigeration apparatus of claim 1 wherein said humidity sensing means is arranged to sense the humidity in said chamber.
Claim 4
Dependent Claim
41 words
The refrigeration apparatus of claim 1 wherein said cooling means are provided externally of said chamber, and said humidity sensing means is arranged to sense the humidity of the air prior to circulation thereof from said chamber to said cooling means.
Claim 5
Dependent Claim
46 words
The refrigeration apparatus of claim 1 wherein means are provided for operating said cooling means whenever the temperature in said chamber is above a preselected temperature, and said control means is arranged to integrate the sensed humidity with time only during operation of said cooling means.
Claim 6
Dependent Claim
122 words
In a refrigeration apparatus having means defining a chamber to be refrigerated, cooling means for providing refrigerated air within said apparatus to said chamber, and defrosting means for defrosting said cooling means, control means for controlling the operation of said defrosting means comprising: humidity sensing means for sensing the humidity of said air within said apparatus; means for integrating the humidity sensed by said humidity sensing device with time for initiating a defrosting operation by said defrosting means as a result of a preselected integrated amount of said sensed humidity and time; and means for resetting the integrating means during the defrosting operation to permit a subsequent defrost operation initiation upon again reaching said preselected integrated amount of sensed humidity and time.
Claim 7
Dependent Claim
122 words
In a refrigeration apparatus having means defining a chamber to be refrigerated, cooling means for providing refrigerated air within said apparatus to said chamber, and defrosting means for defrosting said cooling means, control means for controlling the operation of said defrosting means comprising: humidity sensing means for sensing the humidity of said air within said apparatus; means for integrating the humidity sensed by said humidity sensing device with time for initiating a defrosting operation by said defrosting means as a result of a preselected integrated amount of said sensed humidity and time; and means for resetting the integrating means during the defrosting operation to permit a subsequent defrost operation initiation upon again reaching said preselected integrated amount of sensed humidity and time.
Claim 8
Dependent Claim
32 words
The refrigeration apparatus of claim 5 wherein said integrating means comprises a coulometer E-cell and said resetting means comprises means for applying a reverse current to said E-cell during the defrosting operation.
Claim 9
Dependent Claim
25 words
The refrigeration apparatus of claim 5 including timing means for timing the duration of the defrosting operation and terminating the operation of said resetting means.
Claim 10
Dependent Claim
52 words
The refrigeration apparatus of claim 5 wherein said cooling means includes an evaporator, means for circulating air successively in heat exchange with said evaporator, to said chamber, and back to said evaporator, and said humidity sensing means is disposed to sense the humidity of the air being circulated back to the evaporator.
Claim 11
Dependent Claim
69 words
In a refrigerator having a refrigerated compartment, an evaporator for refrigerating the air within the compartment, and means for defrosting the evaporator, the method of controlling the initiation of a defrosting operation comprising the steps of: sensing the moisture content of the air within the compartment; integrating the sensed moisture content with time; and initiating operation of the defrosting means upon the accumulation of a predetermined moisture content-time integral.
Claim 12
Dependent Claim
69 words
In a refrigerator having a refrigerated compartment, an evaporator for refrigerating the air within the compartment, and means for defrosting the evaporator, the method of controlling the initiation of a defrosting operation comprising the steps of: sensing the moisture content of the air within the compartment; integrating the sensed moisture content with time; and initiating operation of the defrosting means upon the accumulation of a predetermined moisture content-time integral.
Claim 13
Dependent Claim
81 words
In a refrigerator having a refrigerated compartment, an evaporator for refrigerating the air within the compartment, and means for defrosting the evaporator, the method of controlling the initiation of a defrosting operation comprising the steps of: sensing the relative humidity of the air within the compartment; integrating the sensed relative humidity with time; generating a signal which is dependent upon the accumulated humidity-time integral; and initiating operation of the defrosting means in response to a predetermined state of the generated signal.
Claim 14
Dependent Claim
81 words
In a refrigerator having a refrigerated compartment, an evaporator for refrigerating the air within the compartment, and means for defrosting the evaporator, the method of controlling the initiation of a defrosting operation comprising the steps of: sensing the relative humidity of the air within the compartment; integrating the sensed relative humidity with time; generating a signal which is dependent upon the accumulated humidity-time integral; and initiating operation of the defrosting means in response to a predetermined state of the generated signal.
Claim 15
Dependent Claim
35 words
The method Of initiating a defrosting operation as defined in claim 10 wherein the step of integrating humidity with time is carried out when air is being circulated over the evaporator and into the compartment.
Claim 16
Dependent Claim
40 words
The method of initiating a defrosting operation as defined in claim 10 further including the steps of de-energizing the defrosting means after a timed period of operation and initiating a subsequent period of sensing and integrating relative humidity with time.
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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) | 1976-09-17 | 1977-03-19 | 1977-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-17 | 1981-03-19 | 1981-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-17 | 1985-03-19 | 1985-09-18 | $7700.00 | Window Closed / Lapsed |