Refrigerator door ajar alarm with variable delay
First Claim
1. In a refrigeration apparatus having means defining a refrigerated compartment and a door for providing access to said compartment, an improved door ajar alarm comprising:
- means for sensing when said door is open;
means for sensing an operating condition of said refrigeration apparatus other than the position of said door;
means for providing an alarm; and
control means coupled to said door sensing means, said condition sensing means and said alarm means for actuating said alarm means in response to said door being open for a period of time which varies in accordance with the sensed operating condition of the refrigeration apparatus.
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Accused Products
Abstract
A door ajar alarm system for a refrigerator-freezer, the system having a variable alarm delay period. The door ajar alarm system includes a control which may be digital or analog for monitoring various operating conditions of the refrigerator such as the temperatures of the refrigerator compartments and whether the refrigerator is undergoing a defrost operation. The control determines the alarm delay period in accordance with the monitored conditions such that the delay period is decreased in response to each monitored condition which reaches a predetermined status. The door ajar alarm thus alerts the user to operating conditions which are likely to produce an undesirable temperature within the refrigerator more rapidly than usual or to produce temperatures from which recovery is unusually slow.
48 Citations
18 Claims
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1. In a refrigeration apparatus having means defining a refrigerated compartment and a door for providing access to said compartment, an improved door ajar alarm comprising:
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means for sensing when said door is open; means for sensing an operating condition of said refrigeration apparatus other than the position of said door; means for providing an alarm; and control means coupled to said door sensing means, said condition sensing means and said alarm means for actuating said alarm means in response to said door being open for a period of time which varies in accordance with the sensed operating condition of the refrigeration apparatus. - View Dependent Claims (2, 3)
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4. In a refrigeration apparatus having means defining a refrigerated compartment and a door for providing access to said compartment, an improved door ajar alarm comprising:
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means for sensing when said door is open; a plurality of sensors, each sensor coupled to the refrigeration apparatus to sense a different operating condition of the apparatus and to provide a signal representing the sensed condition; means for providing an alarm; and control means coupled to said door sensing means, each of said condition sensors and said alarm means for actuating said alarm means when said door has been open for a period of time, said control means including means responsive to each of said condition sensor signals for indicating the status of the sensed conditions to provide a corresponding status signal when a sensed condition reaches a predetermined status, and means responsive to said status signals for determining the period of door open time after which said alarm means is actuated, said period of door open time being varied thereby in accordance with the sensed conditions of the refrigeration apparatus. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11)
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12. In a refrigeration apparatus having means defining a refrigerated compartment and a door for providing access to said compartment, an improved door ajar alarm comprising:
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means for sensing when said door is open to provide a signal which increases with time when the door is open; means for sensing the status of a plurality of operating conditions of the refrigeration apparatus; means coupled to said sensing means for providing a first reference signal which varies in response to the status of each operating condition sensed by the condition sensing means; means for comparing said door open signal to said reference signal to provide a trigger signal when the door open signal exceeds the reference signal; and means for providing an alarm in response to said trigger signal. - View Dependent Claims (13, 14, 15, 16, 17)
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18. In a refrigeration apparatus having means defining an above-freezing compartment, a below-freezing compartment, a door for providing access to said above-freezing compartment, a door for providing access to said below-freezing compartment, and an evaporator having defrost heater, an improved door ajar alarm, comprising:
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a temperature sensor arranged to sense the temperature within one of said compartments; a defrost sensor arranged to indicate the energization of said defrost heater; a first door switch arranged to indicate when said above-freezing compartment door is open; a second door switch arranged to indicate when said below-freezing compartment door is open; an electrically energizable alarm device for producing an audible alarm signal; and a microprocessor-based control for controlling the energization of said alarm device, comprising; means for monitoring said temperature sensor and said defrost sensor and storing signals indicating whether the sensed temperature is above a predetermined temperature and when the defrost heater is energized, respectively; means for establishing a stored count having a value which is determined by said stored temperature signal and said stored defrost signal; means responsive to said first and second door switches and operative whenever either of said doors has been opened for terminating the operation of said count establishing means, and thereafter periodically changing of the value of said stored count; and
,means for energizing said alarm device when said stored count has been changed to a predetermined value.
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Specification