1. Field of the Invention
The present invention pertains to the art of refrigerators and, more particularly, to a control for a refrigerator that establishes and maintains desired fresh food compartment and freezer compartment temperatures, as well as enabling various user selectable features.
2. Discussion of the Prior Art
In general, a refrigerator includes a first or freezer compartment for maintaining foodstuffs at or below freezing, and a second or fresh food compartment for maintaining foodstuffs in a temperature zone between ambient and freezing temperatures. A typical refrigerator includes a refrigeration system having a compressor, a condenser coil, a condenser fan, an evaporator, and an evaporator fan.
In operation, temperature sensors provided within the refrigerator are used to measure temperatures in the fresh food and freezer compartments. When a door associated with either compartment is opened, the resulting loss of cool air will cause the temperature of the compartment to rise. When the temperature of the compartment deviates from a predetermined or pre-selected temperature, the refrigeration system is activated to return the temperature to a point below a consumer or factory established set-point. In order to return the compartment temperature to this point, prior art systems are caused to operate at maximum capacity regardless of the degree of the deviation.
Prior art refrigerators typically employ a wide temperature zone or bounce region that establishes an acceptable temperature range in order to minimize operation of the refrigeration system. A small temperature zone or bounce region results in extended operation of the system, thereby reducing energy efficiency. On the other hand, a wide temperature zone causes temperature fluctuations that may negatively impact quality and/or taste of certain food items.
As part of the overall refrigeration system, a damper is typically provided between the freezer compartment and the fresh food compartment. Operation of the damper is controlled such that cool air is permitted to flow from the freezer compartment to the fresh food compartment. In some arrangements, a fan is mounted within a housing adjacent the evaporator to aid in establishing the airflow. Accordingly, if the temperature of the fresh food compartment rises above the set-point, the damper is opened to allow the passage of cooling air from the evaporator compartment into the fresh food compartment.
In addition, one or more fans have been incorporated into the fresh food compartment to circulate or evenly distribute the cooling air in order to minimize temperature stratification. Typically, the fan(s) is continuously operated when the fresh food door is closed. However, operating the fan when the damper is open may cause too much cooling air to be drawn into the fresh food compartment. In any event, in addition to controlling refrigeration components, dampers and fans, many refrigerators include controls that enable a consumer to selectively activate various features to tailor operation of the refrigerator to suit a particular need.
Regardless of the teachings in the prior art, there still exists a need for an enhanced refrigerator control system. More specifically, there exists a need for a refrigerator controller that combines operation of the damper and a fan in the fresh food compartment to maintain desired compartment temperatures. In addition, there exists a need for a controller that can determine a direction and magnitude of change of temperature in the fresh food and/or freezer compartments to provide greater sensitivity in order to minimize activation of the refrigeration system, as well as blend various user selectable features to obtain a synergistic combination that appeals to consumers.
The present invention is directed to a refrigerator including an outer shell or cabinet within which is defined a fresh food compartment and a freezer compartment. In a manner known in the art, the refrigerator includes a pair of doors pivotally mounted to the cabinet to selectively access the fresh food and freezer compartments. In a manner also known in the art, the refrigerator includes a refrigeration system for regulating temperatures in the fresh food and freezer compartments. A duct is provided to fluidly interconnect the freezer compartment and the fresh food compartment. Arranged along the duct is a damper which selectively shifts between an open position, wherein cool air flows into the fresh food compartment, to a closed position depending upon a sensed need for cooling in the fresh food compartment.
In accordance with the invention, an air mixing fan is arranged in the fresh food compartment. The air mixing fan is selectively activated to establish a cooling airflow in the fresh food compartment to eliminate, or at least minimize, temperature stratification. The refrigerator further includes an ice maker, a user interface having a plurality of control elements and a controller operatively associated with the user interface. The controller includes a memory having stored therein a plurality of operating parameters for controlling various aspects or features of the refrigerator.
In accordance with a preferred form of the invention, the operating parameters include a temperature control mode, a super cool mode, a food saver mode and a quick ice mode. The temperature control mode is employed to establish and maintain temperatures in the fresh food and freezer compartments. More specifically, the temperature control mode monitors for temperature trends. That is, if a magnitude and direction of a temperature of the freezer compartment indicates a warming trend, the refrigeration system is activated. Conversely, a cooling trend causes the refrigeration system to turn off. The temperature of the fresh food compartment is also monitored and controlled in a similar manner. That is, if in a warming trend, the damper is opened, allowing cool air into the fresh food compartment. If in a cooling trend, the damper is closed.
The super cool mode is designed to lower a temperature of the fresh food compartment to overcome a temperature stratification effect caused by, for example, periodic door openings or the addition of a large, warm load. More specifically, repeatedly opening the door and releasing cooler air or placing a large item that is at, near or above room temperature into the fresh food compartment can create a temperature stratification effect in the fresh food compartment and may even raise the temperature of the fresh food compartment above selected levels. In order to proactively address the potential sudden increase in temperature, a consumer can selectively activate the super cool mode wherein the cooling trend in the fresh food compartment is adjusted to compensate for loss of cool air or the added heat, preferably by activating the mixing fan at full power if the damper is closed. If the damper is open, the air mixing fan is not active. In this manner, the temperature of the fresh food compartment can be normalized without exceeding any pre-set compartment temperature.
A consumer can rapidly lower temperatures in both the fresh food and freezer compartments by activating the food saver mode. When in the food saver mode, the controller automatically lowers the temperature of each of the fresh food and freezer compartments to a minimum setting for a predetermined period of time. Finally, if the consumer wishes to shorten ice production time, the quick ice mode is activated. When operating in the quick ice mode, the controller automatically lowers the temperature of the freezer compartment to a minimum setting for a first predetermined time period and, in one preferred embodiment, each time the ice maker is filled with water, activates the evaporator fan for a second predetermined time period.
Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of a preferred embodiment when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.
With initial reference to
In a manner known in the art, fresh food compartment 8 is provided with a plurality of vertically height adjustable shelves 20-22 supported by a pair of shelf support rails, one of which is indicated at 25. At a lowermost portion of fresh food compartment 8 is illustrated a pair of temperature controlled bins 28 and 29, as well as a conventional storage compartment 30. At an upper region of fresh food compartment 8 is a temperature control housing or user interface 40. In the embodiment shown, user interface 40 includes a display zone 42 and a plurality of control elements 45-49. Control elements 45-48 are constituted by temperature control elements for adjusting a temperature of fresh food compartment 8 and freezer compartment 9, while control element 49 is constituted by an auxiliary control element for re-setting, for example, a door alarm. For the sake of completeness, interface 40 is shown to include a light 54 which, in a manner known in the art, is controlled by a switch 56 operated by opening and closing door 10.
With further reference to
In order to regulate the flow of cooling air into fresh food compartment 8, a damper 82 is arranged within duct 80. More specifically, based on a cooling demand as sensed by, for example, a fresh food compartment temperature sensor 90, damper 82 shifts between a closed position and an open position. That is, in response to a sensed need for cooling, damper 82 opens to allow cool air to flow into fresh food compartment 8. In accordance with one aspect of the invention, the degree of opening of damper 82 depends upon a particular cooling requirement. More specifically, the greater the need for cooling, the greater the shift to the open position. In a similar manner, if there is a need for cooling freezer compartment 9 as sensed by, for example, a freezer temperature sensor 91, evaporator fan 68 is activated. Input is also received from an ambient sensor 92 to further enhance temperature regulation. Additional temperature regulation is provided for fresh food compartment 8 with the incorporation of an air mixing fan 95. When activated, air mixing fan 95 circulates cooling air in fresh food compartment 8 in order to eliminate, or at least substantially reduce, temperature stratification.
In accordance with the invention, refrigerator 2 includes a CPU or controller 100 having a memory 102. Controller 100 regulates operation of refrigerator 2 based upon factory settings and/or selected user preferences. User preferences may include setting preferred temperatures for fresh food compartment 8 and freezer compartment 9, as well as various model dependent, special features incorporated into refrigerator 2. That is, each model refrigerator may include one or more available special features that could be activated through user interface 40. Toward that end, stored in memory 102 are various operating parameters for refrigerator 2. In accordance with the embodiment shown, the operating parameters include: a temperature control mode 120, a super cool mode 124, a food saver mode 128, a quick ice mode 132 and a defrost mode 136. In addition, CPU 100 controls operation of temperature control bins 28 and 29, as well as numerous other features which do not form part of the present invention.
In accordance with a preferred form of the invention, temperature mode 120 includes at least two sub-routines. That is, temperature mode 120 includes a fresh food sub-routine that monitors a magnitude and direction of a temperature in fresh food compartment 8 to establish and maintain a temperature within fresh food compartment 8 and a freezer sub-routine that monitors a magnitude and direction in freezer compartment 9 to establish and maintain a temperature in freezer compartment 9. Thus, by monitoring both magnitude and direction of temperatures, temperature mode 120 monitors trends in temperature which are employed to maintain fresh food and freezer compartments 8, 9 temperatures at a desired setting as will be discussed more fully below.
Referring to
In warming mode or routine 197, controller 100 determines whether the temperature of fresh food compartment 8 (TFF) is greater than or equal to a set point temperature (TSP) plus a cut-in temperature (Tcut-in). That is, controller 100 determines whether the temperature in fresh food compartment 8 is above a consumer or factory established set point (TSP) plus the cut-in temperature (Tcut-in) value for compressor 65. If the temperature is greater or equal to this value, additional cooling is deemed necessary and a cooling flag is set in step 208. Once a cooling flag is set, controller 100 opens damper 82 and activates evaporator fan 68 in order to begin to pull down or lower the temperature of fresh food compartment 8 to the desired level.
Obviously, if in step 195, a cooling flag is active, fresh food sub-routine 145 moves to cooling mode step 199. At this point, controller 100 determines whether the temperature of fresh food compartment 8 is less than or equal to the set point temperature (TSP) less a temperature cut-out (Tcut-out) value for compressor 65 in step 216. That is, if the temperature of fresh food compartment 8 is less than or equal to the established set point temperature (TSP) less a cut-out value (Tcut-out) for compressor 65, no additional cooling is required and a warming flag is set in step 218. Once warming flag is set in step 218, damper 82 is closed and evaporator fan 68 is deactivated in step 220.
If in step 206 it is determined that the temperature of fresh food compartment 8 is less than the set point temperature (TSP) plus the cut-in temperature (Tcut-in), warming mode step 197 shifts to step 218 in cooling mode step 199 and a warming flag is set ensuring that damper 82 is closed and evaporator fan 68 is deactivated. Likewise, if in cooling mode 199, controller 100 determines that the temperature of fresh food compartment 8 is greater than or equal to the set point temperature (TSP) minus the cut out value (Tcut-out) in step 216, cooling mode step 199 shifts to step 208 in warming mode 197, a cooling flag is set, damper 82 is opened and evaporator fan 68 is activated.
Reference will now be made to
In the warming mode step 166, controller 100 determines whether the temperature of freezer compartment (TFZ) 9 is greater than the set point temperature (TSP) plus the cut-in temperature (Tcut-in) in step 172. At this point, it should be understood that the TSP and Tcut-in values for freezer compartment 9 differ from those used for fresh food compartment 8. In any case, if the temperature in freezer compartment 9 (TFZ) is greater than the set point temperature (TSP) plus the cut-in temperature (Tcut-in), additional cooling is required and a cooling flag is set in step 174. At this point, compressor 65 and evaporator fan 68 are activated in step 176 to bring down or lower the temperature in freezer compartment 9.
If it is established in step 164 that the temperature in freezer compartment 9 is cooling, freezer temperature sub-routine 147 moves to cooling mode in step 168. Once in the cooling mode step 168, controller 100 determines whether the temperature in freezer compartment 9 is less than or equal to the temperature set point (TSP) less the cut-out temperature (Tcut-out) in step 182. If the temperature of freezer compartment 9 is less than or equal to the set-point temperature minus the cut-out temperature for compressor 65, no additional cooling is required and a warming flag is set in step 184. At this point, compressor 65 and evaporator fan 68 are deactivated in step 186.
In a manner similar to that described above, if in step 172 controller 100 determines that the temperature of freezer compartment 9 (TFZ) is greater than TSP+CUT-IN, freezer temperature sub-routine 147 shifts to step 184 of the cooling mode. Likewise, if in step 182 it is determined that the temperature of freezer compartment 9 (TFZ) is greater than TSP−TCUT-IN, freezer temperature sub-routine 147 shifts to step 174 of the warming mode followed by the activation of compressor 65 and evaporator fan 68 in step 176.
Reference will now be made to
Reference will now be made to
Next, your attention is directed to
In accordance with the invention, once selected, quick ice mode 132 remains active for a predetermined period of time, for example, 48 hours or until manually shut-off. Thus, in step 342 a determination is made as to whether the predetermined time has elapsed. If the predetermined time has elapsed, controller 100 returns a set point temperature for freezer compartment 9 to a preset level in step 334 and thereafter terminates. Alternatively, if the predetermined time period has not passed, controller 100 checks whether quick ice mode 132 has been manually deactivated in step 346. If so, quick ice mode 132 moves to step 344 and thereafter terminates. If, however, quick ice mode 132 has not been deactivated in step 346, the temperature of freezer compartment 9 will remain at the reduced or minimum set point and the operation of valve 77 continues to be monitored.
In an alternative arrangement, quick ice mode 132 can be automatically deactivated if valve 77 has not opened for a predetermined period of time. That is, if after a predetermined period of time, for example 12 hours, valve 77 does not open to refill ice maker 75, there is no longer deemed a need for continued ice production. More specifically, if in step 338 valve 77 has not opened for a second predetermined period of time, quick ice mode 132 moves to step 345 to determine whether the second predetermined time has elapsed. If so, quick ice mode 132 moves to step 344 returning the set point of freezer compartment 9 to a normal or pre-established level and thereafter terminates.
For the sake of completeness, controller 100 can initiate a defrost mode 136. For use with the invention, the defrost mode can operate on an adaptive and/or pre-emptive basis when a determination is made that the evaporator (not shown) requires de-icing. In accordance with one embodiment, defrost mode 136 senses door openings of refrigerator 2 to determine periods of low or little usage. The periods of low or little usage are grouped into blocks which correspond to various time periods of a day. Preferably, controller 100 will not activate defrost mode 136 in a high usage block and, most preferably, activates defrost mode 136 in a low, preferably the lowest, usage block.
In any event, with the above arrangement, it is possible to operate refrigerator 2 in a manner which enhances control of fresh food compartment 8 and freezer compartment 9. More specifically, the various operating modes outlined above can be selected individually or synergistically combined to efficiently operate refrigerator 2. Depending on a consumer's particular needs, he/she can simply access interface 40 to select or adjust various operating parameters of refrigerator 2 including the activation/deactivation of the various modes as set forth in accordance with the invention.
Although described with reference to a preferred embodiment of the invention, it should be readily understood that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For instance, while the user interface is illustrated at an upper portion of the fresh food compartment, other locations, such as on one of doors 10 and/or 12, would also be acceptable. In general, the invention is only intended to be limited by the scope of the following claims.
The present application represents a divisional of U.S. patent application Ser. No. 11/327,342 entitled “Control for a Refrigerator” filed Jan. 9, 2006, pending.
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Number | Date | Country | |
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Parent | 11327342 | Jan 2006 | US |
Child | 12820173 | US |