1. Field of the Invention
The present invention pertains to the art of refrigerated appliances and, more particularly, to a refrigerator including a fresh food compartment stirring fan assembly for establishing a substantially uniform compartment temperature, with the stirring fan assembly including a removable filter for eliminating odors and other contaminants within the appliance.
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, in fluid communication with the freezer compartment, for maintaining foodstuffs in a temperature zone between ambient and freezing temperatures. A typical refrigerator includes a refrigeration system including a compressor, an evaporator, a condenser, a main cooling fan for developing a flow of cold air, and a damper located in a passageway interconnecting the freezer and fresh food compartments. In operation, one or more temperature sensors provided within the refrigerator measure at least one internal refrigerator compartment temperature. When the internal temperature of the refrigerator deviates from a predetermined set point temperature, the refrigeration system operates to return the temperature to a point below the set-point.
In general, the largest temperature deviations occur in the freezer compartment. Due to the low temperature at which the freezer compartment is maintained, changes in the freezer compartment, resulting from door openings, ambient temperature changes or the like, can have a substantial impact on the temperatures in each of the fresh food and freezer compartments. In order to return the freezer compartment to the set point temperature, the passageway interconnecting the fresh food and freezer compartments is closed off through operation of the damper. At this time, the freezer and fresh food compartment are isolated from one another. With this arrangement, the main cooling fan is operated to direct an airflow over the evaporator into the freezer compartment. Using this approach, the temperature rise in the freezer compartment can be compensated for in an efficient manner. Unfortunately, when the compartments are isolated one from the other, a temperature stratification can occur in the fresh food compartment due to lack of air circulation.
In order to address such temperature stratification situations, it has been proposed in the prior art to incorporate elaborate air ducting systems and/or a dedicated fan to circulate air within the fresh food compartment. In general, elaborate ducting arrangements not only significantly add to the overall cost of the refrigerator, but effectively limit the space available for storing food items. In connection with known fan arrangements, an airflow is generated whereby air is drawn into the fan and distributed back into the compartment. As such, a more uniform temperature distribution is established within the compartment. However, recirculating the same air within the compartment is not without drawbacks. For instance, contaminants, in the form of dust and the like, tend to settle on internal fan surfaces, only to be later distributed onto food items located within the fresh food compartment.
In addition, odors emanating from stored food can be circulated around the compartment, thereby cross-contaminating, altering the taste of, and otherwise negatively impacting the attractiveness of remaining food items. Certainly, problems associated with refrigerator odors are not new. There are a variety of products on the market which purport to eliminate odors released from food. For instance, in an attempt to eliminate odors, some consumers place open boxes of baking soda within the fresh food compartment, with the baking soda acting to absorb a portion of the odors released by the food. Other consumers use commercial air fresheners to either cover up, or absorb food odors. Regardless of these arrangements, unless the full airflow can be treated, odors within the compartment will not be eliminated.
Regardless of these prior art attempts to address potential temperature stratification and odor problems in a food storage compartment of a refrigerator, there exists a need in the art for a fresh food compartment stirring fan assembly which is both capable of effectively minimizing compartment temperature gradients and accommodates filtering of a recirculated airflow.
The present invention is directed to a refrigerator air circulation and filtration system. More specifically, the invention is directed to an air circulation system used in connection with a refrigerator having at least a fresh food compartment within which is mounted a stirring fan. In accordance with one preferred form of the invention, a damper is arranged within a passageway to isolate the fresh food compartment from a freezer compartment during select cooling periods. Since the fresh food compartment is, at times, isolated from the freezer compartment, the stirring fan is operated to circulate the fresh food compartment air in order to maintain a substantially uniform temperature within the compartment. In accordance with another preferred form of the invention, the stirring fan is employed in connection with a fresh food compartment which is fluidly isolated from any freezer compartment.
In any case, in accordance with the most preferred embodiments, the stirring fan is mounted in a rear portion of the fresh food compartment. Preferably, the fan includes a removable cover having a central portion into which is drawn fresh food compartment air, and a peripheral portion, from which emanates a recirculated airflow within the fresh food compartment. In addition, a filter element is arranged beneath the cover at the central portion, such that incoming air can be treated to substantially eliminate odors and other airborne contaminants.
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
Mounted in an upper region of fresh food compartment 8 is a temperature control housing 18 into which opens a passage 19 (see
To this point, the above-described structure is known in the art and presented only for the sake of completeness. The present invention is actually directed to the incorporation of a fresh food compartment stirring fan assembly, which is generally indicated at 30, within fresh food compartment 8 of refrigerator 2. As will be detailed more fully below, stirring fan assembly 30 is mounted on a rear wall portion 32 of fresh food compartment 8 in order to reduce temperature stratification within fresh food compartment 8.
With reference to
Fan 35 includes a plurality of vanes 41 extending from central hub 37 and terminate short of base member 33. More specifically, base member 33 includes a base plate 42 and an upstanding, annular side wall 43 defining a central through hole 44 within which vanes 41 of fan 35 are rotatably arranged. Base member 33 is adapted to be mounted within a housing 45. In accordance with the most preferred embodiment of the invention, housing 45 includes a side wall portion 46 having an associated lower edge 47, and an upper central ledge portion 48 having a central opening 49. As shown, ledge portion 48 is preferably provided with a plurality of slots 50 at spaced peripheral locations.
Projecting downwardly from ledge portion 48 are spaced bosses, one of which is illustrated at 52 in
Stirring fan assembly 30 also includes a cover or cap 60 detachably mounted to ledge portion 48. More specifically, detachable cover 60 includes a plurality of inlet openings 62 arranged about an upper surface 63. A plurality of tabs 64 project from a peripheral portion 65 of cover 60. With this preferred arrangement, tabs 64 are adapted to be frictionally received within slots 50 arranged on ledge portion 48 of housing 45. Regardless of the particular mounting arrangement employed, cover 60 can be readily, selectively detached from housing 45. Also provided as part of stirring fan assembly 30 is a filter 67, such a foam or fiber insert, which is positioned within detachable cover 60. That is, filter 67 is either located entirely within cover 60 or against ledge portion 48. In either case, filter 67 is preferably maintained outside of housing 45. In this manner, filter 67 is arranged at an inlet of fan 35 such that contaminants carried by an incoming airflow are substantially removed prior to the airflow recirculating back into fresh food compartment 8.
In general, the cooling aspect of refrigerator 2 operates in a manner known in the art wherein a consumer operates at least one control setting element 70 provided on temperature control housing 18 to establish desired operating temperatures for freezer compartment 13 and fresh food compartment 8. Depending upon the relative temperature differences between desired set points and actual compartment temperatures, a cooling system 77 and damper 20 will be controlled. Typically, damper 20 is moved to a closed position to effectively isolate freezer compartment 13 from fresh food compartment 8 in order to shorten the time required to bring freezer compartment 8 to the desired temperature. On the other hand, the opening of damper 20 is regulated in order to establish a requisite amount of cooling air flowing from freezer compartment 13 to fresh food compartment 8 through passage 19. In this general fashion, refrigerated temperatures are established in each of fresh food and freezer compartments 8 and 13.
As freezer compartment 13 is maintained at a substantially lower temperature relative to fresh food compartment 8, cooling system 77 is operated more frequently to correct for temperature losses in freezer compartment 13. Since freezer compartment 13 is generally isolated from fresh food compartment 8 during these periods of correction, air maintained within fresh food compartment 8 can become stagnate. The stagnate air tends to cause the internal temperature within fresh food compartment 8 to stratify, i.e., a temperature gradient with regions of high and low temperatures develop within fresh food compartment 8. In order to substantially reduce temperature stratification, fan 35 is operated to recirculate air within fresh food compartment 8.
In accordance with this preferred embodiment of the invention, whenever fresh food compartment 8 is isolated from freezer compartment 13 through the closing of damper 19, stirring fan assembly 30 is operated. As indicated above, stirring fan assembly 30 is preferably mounted to rear wall portion 32 of liner 6 that defines fresh food compartment 8. In the preferred embodiment shown in
With this arrangement, during operation of stirring fan assembly 30, air is drawn into inlet openings 62 and directed through filter 67. The airflow past vanes 41 of fan 35 is forced radially outwardly in all directions through the gap or space between liner 6 and side wall portion 46 of housing 45. Therefore, as best shown in
In the preferred form of the invention represented in
Also contemplated in accordance with the present invention is to have CPU 85 establish various operating modes for fan 35. For instance, CPU 85 can receive signals from one or more compartment temperature sensors 90 for use in regulating the activation/deactivation state, fan speed, percent run time, and a delay in starting of fan 35. More specifically, it is possible to employ multiple compartment temperature sensors 90 in various portions of fresh food compartment 8 to more accurately sense temperature gradients therein in order to either control the activation/deactivation state of fan 35 or, in the case of employing a variable speed motor, the operating speed of fan 35. The temperature sensors employed also preferably include an ambient temperature sensor 92. Within the scope of the invention, these signals can be used to operate fan 35 at a higher speed when there is a larger difference between the internal temperature of fresh food compartment 8 and the ambient temperature, given that the opening of door 10 will have a larger adverse effect on the overall temperature gradient. In any event, it should be readily apparent that CPU 85 can receive various signals to regulate the operation of fan 35 to efficiently maintain a substantially uniform temperature within fresh food compartment 8 with the inclusion of the stirring fan assembly 30 of the present invention, while also operating in a more conventional manner to provide a basic flow of cooling air into each of fresh food compartment 8 and freezer compartment 13.
Due to the inclusion of filter 67, odors carried by the air within fresh food compartment 8 will be, at least, substantially reduced. Therefore, the consumer will be provided with an enhanced, fresh smelling compartment arrangement without requiring the replacement of a box of baking soda or the like within fresh food compartment 8. As cover 60 is readily detachable from housing 45, filter 67 can be easily removed for washing or replacement as necessary.
Although housing 45 has been described as being mounted to a substantially central rear surface of fresh food compartment 6, it should be understood that housing 45 could be mounted at other locations, particularly at an upper portion of fresh food compartment 6, such as directly beneath or at least partially behind control housing 18. Additional modifications can also be readily employed. For instance,
In accordance with this embodiment, mounting pins 178 and 179 are adapted to be received in respective bores formed at an upper portion of fresh food compartment 6, such as at least partially behind temperature control housing 18, or directly in temperature control housing 18. To this end, projecting from an exterior surface and extending along a longitudinal length of each mounting pin 178 and 179 are a plurality of fin elements indicated generally at 185 and 186. With this arrangement, mounting pins 178 and 179 can be inserted into respective receiving bores (not shown) with fin elements 185 and 186 providing an interference fit securing housing base member 150 within fresh food compartment 6. In addition, one or more mechanical fasteners (not shown) can be employed to secure housing base member 150 within fresh food compartment 6.
As best seen in
Positioned between main body portion 205 and cover receiving section 210 is a fan support web or ledge 220. As shown, fan support web 220 includes a central opening 226 and a plurality of fan mounting apertures 231-234 which, in accordance with this form of the invention, are adapted to receive a mechanical fastener for securing fan 35 to main housing 152. Finally, extending from a lower region of main body portion 205 is an outlet shroud 240. As will be discussed more fully below, in accordance with this form of the invention, shroud 240 is adapted to direct a recirculated airflow, which is drawn into fan 35 through cover 250, to various regions of fresh food compartment 6.
As set forth above, secured to cover receiving section 210 of main body portion 205 is a vented cover 250 (see
In accordance with the embodiments illustrated in
Although described with reference to preferred embodiments of the present 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, the filter element can be mounted either in an upstream or downstream portion of the overall fan assembly so long as air passing through the fan assembly is adequately filtered. Alternatively, the filter can be removed completely from the system. In addition, while the refrigerator described above incorporates an opening passing between the freezer compartment and the fresh food compartment, it should be understood by one of ordinary skill in the art that the present invention is equally applicable to refrigerators having a freezer compartment and a fresh food compartment isolated one from the other, or even a refrigerator only having a fresh food compartment. In general, the invention is only intended to be limited by the scope of the following claims.