US4821528A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fault tolerant control for a refrigerator
Assignee: Whirlpool Corp
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Filing: 1988-02-10
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Granted: 1989-04-18
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Expires: 2008-02-10
Abstract
Abstract In an improved control for a refrigerator, critical components such as fresh food and freezer compartment temperature sensors, temperature set devices and baffle are sampled to conform that each is operational. Upon diagnosis of a critical component failure or of multiple component failures, the control, using stored control parameters, operates the remaining components in a manner that will continue to preserve food.
Inventors
- 👤 Andrew T. Tershak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 02:02
CPC Classifications
G; G05; G05D; G05D23/00; G05D23/19; G05D23/1917; F; F25; F25D; F25D17/00; F25D17/04; F25D17/042; F25D17/045; G05B; G05B9/00; G05B9/02; F25B; F25B2500/00; F25B2500/06; F25D2400/00; F25D2400/06
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
181 words
In a refrigerator having a cabinet defining a first, below freezing compartment and a second, above freezing compartment, a compressor for cooling said first compartment, a wall having an opening between said compartments, a baffle for selectively closing said opening, first and second temperature sensing means for sensing respectively the temperatures in said first and second compartments, first and second temperature setting means for setting the temperatures respectively of said first and second compartments to user selected first and second temperatures: memory means for storing plural open loop compressor control parameters; and microprocessor means programmed to be responsive to said first and second temperature sensing means and to said first and second temperature setting means to control selectively said compressor and said baffle to maintin said first and second compartments at said first and second user selected temperatures; said microprocessor means being further programmed to detect faults in both said first temperature sensing means and said baffle and, in response, to control said compressor using a predetermined one of said plural open loop compressor control parameters stored in said memory means.
Claim 2
Dependent Claim
181 words
In a refrigerator having a cabinet defining a first, below freezing compartment and a second, above freezing compartment, a compressor for cooling said first compartment, a wall having an opening between said compartments, a baffle for selectively closing said opening, first and second temperature sensing means for sensing respectively the temperatures in said first and second compartments, first and second temperature setting means for setting the temperatures respectively of said first and second compartments to user selected first and second temperatures: memory means for storing plural open loop compressor control parameters; and microprocessor means programmed to be responsive to said first and second temperature sensing means and to said first and second temperature setting means to control selectively said compressor and said baffle to maintin said first and second compartments at said first and second user selected temperatures; said microprocessor means being further programmed to detect faults in both said first temperature sensing means and said baffle and, in response, to control said compressor using a predetermined one of said plural open loop compressor control parameters stored in said memory means.
Claim 3
Dependent Claim
74 words
The apparatus of claim 1, wherein said memory means stores a first compressor open loop control parameter corresponding to the baffle failed open and a second compressor open loop control parameter corresponding to the baffle failed closed, and said microprocessor means is programmed to control said compressor using selectively the first and second open loop control parameters corresponding to a diagnosed condition of said baffle when said first temperature sensing means is diagnosed failed.
Claim 4
Dependent Claim
35 words
The apparatus of claim 2, wherein said first compressor open loop control parameter corresponds to an energized and deenergized duty cycle of the compressor lower than that of said second compressor open loop control parameter.
Claim 5
Dependent Claim
163 words
In a refrigerator having a cabinet defining a first, below freezing compartment and a second, above freezing compartment, cooling means for cooling said first compartment, a wall defining an opening between said compartments, a baffle operative for selectively opening said closing, operating means for operating said baffle, first and second temperature sensing means for measuring the temperatures of said first and second compartments, temperature setting means for storing user selected first and second compartment temperatures and control means responsive to said temperature sensing means and said temperature setting means for controlling said cooling means to maintain the first compartment at said user selected first compartment temperature and for controlling said baffle to maintain said second compartment at said user selected second compartment temperature; an operating method, comprising the steps of: detecting a failure of said baffle and of said first temperature sensing means to operate; and, in response, controlling said cooling means to operate at a first predetermined energized and deenergized duty cycle.
Claim 6
Dependent Claim
163 words
In a refrigerator having a cabinet defining a first, below freezing compartment and a second, above freezing compartment, cooling means for cooling said first compartment, a wall defining an opening between said compartments, a baffle operative for selectively opening said closing, operating means for operating said baffle, first and second temperature sensing means for measuring the temperatures of said first and second compartments, temperature setting means for storing user selected first and second compartment temperatures and control means responsive to said temperature sensing means and said temperature setting means for controlling said cooling means to maintain the first compartment at said user selected first compartment temperature and for controlling said baffle to maintain said second compartment at said user selected second compartment temperature; an operating method, comprising the steps of: detecting a failure of said baffle and of said first temperature sensing means to operate; and, in response, controlling said cooling means to operate at a first predetermined energized and deenergized duty cycle.
Claim 7
Dependent Claim
54 words
The method of claim 1, wherein said detecting step includes detecting whether the baffle is failed open or is failed closed, and wherein said controlling step includes controlling said cooling means to operate selectively at first or second energized and deenergized duty cycles corresponding respectively to whether said baffle is failed open or closed.
Claim 8
Dependent Claim
15 words
The method of claim 5, including the step of displaying an indication of a failure.
Claim 9
Dependent Claim
79 words
The method of claim 4, wherein said baffle is a type that is movable between open and closed positions in response to temperature, and said refrigerator further has a baffle heater including a resistor for heating said baffle to impart movement thereto, said method further including the steps of storing an open loop baffle control parameter, detecting an electrically noisy electrical heater and, in response to an electrically noisy heater resistor, controlling said baffle with said open loop parameter.
Claim 10
Dependent Claim
34 words
The improvement of claim 7, wherein said fault detector means includes means for applying a voltage across said resistive heater means and means for detecting a current flow change through said resistive heater means.
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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) | 1992-04-17 | 1992-10-17 | 1993-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-17 | 1996-10-17 | 1997-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-17 | 2000-10-17 | 2001-04-18 | $7700.00 | Window Closed / Lapsed |