1. Field of the Invention
The present invention relates generally to air filtration and deodorizing devices, and more specifically to a portable device for removably installing in a refrigerator, freezer, or similar cold food storage unit. The present filter device captures objectionable odors in a replaceable treated filter removably disposed within a housing, which is in turn removably installed within the refrigerator or freezer.
2. Description of the Related Art
Food spoilage is a recognized occurrence from time to time in virtually any refrigerator, freezer, or cold storage unit. Even when no power loss occurs, food can still spoil in the above freezing temperatures of a refrigerator, with unpleasant odors being the unfortunate result. Even when no spoilage occurs, the placement of strong and uncomplimentary foods in the confines of a refrigerator, will lead to unpleasant scents throughout the contents.
Accordingly, various means have been developed in the past to reduce or eliminate unpleasant odors in various cold storage devices. Perhaps the most common means known is the simple placement of an open box of baking soda in the interior of the refrigerator or freezer, with the compound serving to absorb odors as air circulates through the cold storage unit. Other devices have been developed as well, but all of the various devices of the prior art known to the present inventor, suffer from one or more drawbacks in terms of odor reduction, portability, cost and complexity, or in some other manner.
Accordingly, a need will be seen for an odor adsorptive filter for installation in a refrigerator, freezer, or other cold storage device as desired. The filter device must be portable for ease of installation and removal, must take up little room in order to avoid loss of interior volume in the unit, and must provide for the adsorption and removal of odor producing compounds within the interior volume of the unit. Moreover, the present invention may also provide for the addition of a pleasant scent to the interior air of the cold storage device, if so desired, and also provide an indication of saturation or loss of adsorptive capabilities for the adsorptive filter which is installed within the filter device.
A discussion of the related art of which the present inventor is aware, and its differences and distinctions from the present invention, is provided below.
U.S. Pat. No. 4,065,262 issued on Dec. 27, 1977 to Mitchell Petroff, titled xe2x80x9cFilter And Air Freshener Apparatus,xe2x80x9d describes a furnace or air conditioning filter having a series of scent vials therein. One or more of the vials may be opened to deploy a scent through the air as it circulates through the filter. The Petroff device cannot be deployed within the relatively small confines of a refrigerator or freezer, without taking up an inordinate amount of the interior volume. Moreover, even if the Petroff filter were placed within a refrigerator or the like, it would do nothing to absorb unpleasant odors within the unit. The Petroff filter is a conventional heating or air conditioning filter which does nothing more than filter dust and the like from the air, with a means of spreading a scent through the air being added.
U.S. Pat. No. 4,948,567 issued on Aug. 14, 1990 to Kousuke Atarashiya, titled xe2x80x9cDeodorizer For Refrigerators Or The Like,xe2x80x9d describes a system which is built in to the air circulation system within a refrigerator and freezer unit. The device includes both adsorbent materials (activated charcoal, etc.) and rare earth catalytic elements, and is installed adjacent the heating element of the defroster system. During normal operation the adsorbent elements capture odors circulating through the system. When the defrost cycle operates, the catalytic elements are heated by the defrost cycle heater, and serve to oxidize and decompose elements trapped by the adsorbents. The elements and function of the Atarashiya system require its permanent installation; they cannot be replaced without considerable effort and disassembly of the unit.
U.S. Pat. No. 4,995,556 issued on Feb. 26, 1991 to Benjamin L. Arnold III, titled xe2x80x9cUnitized Sodium Bicarbonate Deodorizer,xe2x80x9d describes a deodorizing device comprising a series of three perforated concentric shells, each including a quantity of sodium bicarbonate (baking soda) therein. In another embodiment, the baking soda is provided in the form of solid cakes of various shapes. The Arnold, III deodorant devices are essentially throwaway units at the ends of their lives, with no provision for changing the deodorant substance within the container being provided by Arnold, III. Moreover, Arnold, III does not disclose the saturation or impregnation of a fiber matrix with an odor adsorbent material, nor any means of determining when the material requires changing, as provided by the present invention.
U.S. Pat. No. 5,062,272 issued on Nov. 5, 1991 to Marsha L. Burns, titled xe2x80x9cRefrigerator Or Freezer Freshening Device And Process,xe2x80x9d describes a device comprising a canister containing baking soda and/or activated charcoal, along with a scent. As in the Arnold, III device discussed immediately above, the Burns air freshener does not provide for replacement of the adsorbent material within the container; the entire container and contents must be discarded when the contents have expired. Moreover, while Burns provides means for attaching her device to the interior wall of a refrigerator or the like, she uses an adhesive. When such adhesive attachment is removed, it leaves an adhesive residue which must be removed. The present air freshener device uses suction cups for removable attachment to a refrigerator or freezer interior.
U.S. Pat. No. 5,422,078 issued on Jun. 6, 1995 to Amber M. Colon, titled xe2x80x9cApparatus For Providing A Scent,xe2x80x9d describes a holder with orifices therethrough, and a removably replaceable scented insert for the holder. The insert merely contains a scent for distribution from the orifices of the holder; no means of adsorbing odors is disclosed by Colon. The scented insert also differs in construction from the adsorbent insert of the present invention, in that Colon uses a relatively dense thermoplastic material, while the present invention uses a woven or nonwoven fiber insert, with the fibers being coated with the adsorbent material to expose the maximum practicable surface area of adsorbent to the ambient air.
U.S. Pat. No. 5,468,447 issued on Nov. 21, 1995 to Edward M. Bermas, titled xe2x80x9cRefrigerator Freshener,xe2x80x9d describes a container filled with activated carbon and zeolite (aluminum silicate) adsorptive materials. As in the case of the Arnold, III and Burns devices discussed further above, the entire assembly of container and contents of the Bermas device must be discarded when the contents have expired. In contrast, the container of the present air freshener device is reusable, with only the contents requiring replacement. Moreover, Bermas does not provide the means developed for the present invention of exposing the maximum practicable surface area of the adsorbent material to the air, by coating the fibers of a woven or nonwoven fiber mesh with the adsorbent material. Also, Bermas does not provide suction cup attachment for his device, to reduce the amount of space required for the device in the confined interior of a refrigerator or freezer.
U.S. Pat. No. 5,492,675 issued on Feb. 20, 1996 to Cyril J. C. Brizard, titled xe2x80x9cDeodorant System,xe2x80x9d describes a disposable assembly comprising a container and odor adsorbent material therein. As in the Arnold, III, Burns, and Bermas devices discussed further above, the Brizard assembly must be discarded in its entirety when the adsorbent material therein is no longer effective. As noted above, the present device provides a reusable container for holding the replaceable adsorbent contents. Also, it is noted that Brizard provides means for indicating the replacement date, comprising a series of punch-out portions similar to the system used for indicating the purchase date on an automobile battery. This system is inconvenient in a device which may be secured to the rear interior wall of a refrigerator, where it cannot be readily viewed. The present air freshener device also provides a means for indicating the need for replacement of the adsorbent material, but does so by means of a tab or the like extending from the adsorbent, with the tab changing color according to the amount of adsorption activity.
Japanese Patent Publication No. 3-95,379 published on Apr. 19, 1991 to the Toshiba Corporation describes (according to the English abstract) a device which functions similarly to the device of the Atarashiya ""567 U.S. Patent, discussed further above. The drawings appear to show an essentially identical device in both publications. The fact that such devices require permanent installation and are an integral part of the refrigerator and cannot be replaced, has been noted further above.
Finally, Japanese Patent Publication No. 5-18,657 published on Jan. 26, 1993 to Matsushita Refrigeration Company, Ltd. describes (according to the English abstract) a deodorizing system similar to those of the Atarashiya U.S. Patent and ""379 Japanese Patent Publication discussed above. The same points of distinction raised in the discussion of those patent publications, are seen to apply to the ""657 Japanese Patent Publication as well, particularly in view of the drawings in the ""657 Japanese Patent Publication, which appear to show a device essentially similar to those of the Atarashiya U.S. Patent and ""657 Japanese Patent Publication.
None of the above inventions and patents, either singly or in combination, is seen to describe the instant invention as claimed.
The present invention comprises an odor adsorptive filter for installation within a refrigerator, freezer, or other cold storage unit. The present filter contains an exchangeable odor adsorptive filter element, for capturing odoriferous particulates and molecules emanating from various foods stored in the unit. The present filter essentially comprises a filter housing which is removably secured to a back or side wall of the refrigerator or freezer interior (suction cups, etc.) and a filter element removably installed therein. The filter element comprises a woven or nonwoven fiber material, with the odor adsorptive material (baking soda, activated charcoal, etc.) coating the fibers to provide maximum exposed surface area for the adsorptive material.
The filter housing or element may also contain a pleasant scent if so desired, and preferably includes means for indicating when the adsorptive properties of the filter element have expired. The indicator means may comprise a colored tab extending from the element, with the tab changing, losing, or gaining color as it is exposed to the odoriferous particulate and molecules within the refrigerator or freezer. The present odor adsorptive filter provides a significant improvement in efficiency over conventional boxes or containers of baking soda which require shelf space and do not provide the efficiency of the coated fibrous elements of the present filter.
Accordingly, it is a principal object of the invention to provide an improved odor adsorptive filter for adsorbing odoriferous particulate and molecules from the air within a refrigerator, freezer, or other closed cold storage device.
It is another object of the invention to provide an improved odor adsorptive filter incorporating a removably installable filter housing and a filter element which is removably installable within the housing.
It is a further object of the invention to provide an improved odor adsorptive filter which filter element includes odor adsorptive materials selected from the group consisting of baking soda and activated carbon compounds.
Yet another object of the invention is to provide an improved odor adsorptive filter which filter element comprises a woven or nonwoven fibrous structure, with the odor adsorptive material coating the fibers of the filter element to maximize the surface area of the odor adsorptive material.
An additional object of the invention is to provide an improved odor adsorptive filter including means for providing a pleasant scent to the ambient air.
Still another object of the invention is to provide an improved odor adsorptive filter including means for indicating the expiration of the odor adsorptive material therein.
It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become apparent upon review of the following specification and drawings.