US2718765A

US2718765A - Defroster-heater and baffle installation for refrigerator

Info

Publication number: US2718765A
Application number: US302362A
Authority: US
Inventors: Robert A Jansen
Original assignee: Avco Manufacturing Corp
Current assignee: Avco Manufacturing Corp
Priority date: 1952-08-02
Filing date: 1952-08-02
Publication date: 1955-09-27
Anticipated expiration: 1972-09-27

Description

Sept. 27, 1955 R, A, JANSEN 2,718,765

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Sept. 27, 1955 R. A. JANSEN 2,718,765

DEFRosTER-HEATER AND BAFFLE INSTALLATION RoR REFRIGERATOR Filed Aug. 2, 1952 3 Sheets-Sheet 5 INVENToR. IIIQ 4 RoBERr A. JANsE/v.

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DEFROSTER-HEATER AND BAFFLE INSTALLA- TION FOR REFRIGERATOR Robert A. Jansen, Cincinnati, Ohio, as signor to Avco Manufacturing Corporation, Cincumatl, Ohio, a corporation of Delaware Application August 2, 1952, Serial No. 302,362

3 Claims. (Cl. 62-103) This invention concerns a defroster-heater and bafile installation for a refrigerator and relates more` particularly to an installation in which effective bafle defrosting can be accomplished even though physical contact between the baffie and heater is not possible.

The present invention finds particular use in a ref'rrgerator having a defroster-heater which is: attached to the evaporator of the refrigerator to supply heat thereto during periods when defrosting is desired. An installation of a broadly similar type is disclosed and claimed in the Cochran Patent 2,592,394 which issued on April 8, 1952, and is entitled Refrigerator Defrost Product Dsposal System. The Structure disclosed in the Cochran patent cannot be readily adapted for use with a. two door refrigerator of the type having'vertically spaced doors and' a mullion, or barrier strip, which is permanently attached between the side walls of the refrigerator to provideV a sealing surface for the lower edge of the upper door and the upper edge of the lower door. It is in refrigerators of this type that the present invention may be used to particular advantage, the present invention representing a refinement on the Cochran Structure.

Briefly stated, the present invention comprehends the provision of a conventional insulated refrigerator cabinet having an upper freezer compartment and a lower food storage compartment, separate` vertically spaced doors being provided to permit access to eachof these compartments. Such a cabinet usually includes a mul'lon: strip extending horizontally between the side walls of the cabinet in position to provide seating areas, for the contiguous4 edges of the access doors. An evaporator is provided in the upper compartment beneath which is Secured. a defroster-heater element for melting frost which normally accumulates on the evaporator. Two portions of the defroster-heater element are spaced below the evaporator for heating a. bafie provided beneath the evaporator and partially behind the mullion. The baflie not only serves to separate the compartments but also collects water which drips from the evaporator during the defrosting cycle and acts to direct the water to a discharge point.

It is commonplace for frost to form on the evaporator of a refrigerator since the air entering the refri'gerator, when the doors are opened, contains moisture which deposits andV freezes on the relatively cold evaporator. This frost is objectionable since it acts as thermal insulationon the evaporator and retards heat transfer tothe evaporator from the contents of the refrigerator;

Heat may be applied periodically to the evaporator to melt the frost accumulation. As the frost melts, the4 water formed` drips` onto the baffle located beneath the evaporator. Unless heat is also supplied to the baflie during` defrosting, the drip water from the evaporator is likely to refreeze on the bafile when normal Operation is resumed after defrosting. Furthermore, since the bafile regulates convection currents of air within the refrigerator, frost may tend to form on the bafle as these currents flow past it.

Accumulations of ice on the baflie nterfere with its ice 2 airflow control characteristics and with its ability to dispose of the defrost products from the evaporator collected during defrosting. In addition, ice on the bafiie may interfere with its removal from the refrigerator and creates an unsightly appearance, which is highly undesirable.

In the preferred embodiment of the present invention, the defroster-heater element portions, which heat the bafile, extend from front to rear in the cabinet and are disposed within cavities or wells formed in the top of the bafle, which is made from a heat conducting material. These wells act as reservoirs and collect water early in the defrosting cycle, the water wetting the heater portions and acting as a transfer medium for heat passing from the heater to the bafle. The provision of these wells constitutes the mprovement of this invention over the beforementioned Cochran patent.

As will be described more fully hereinafter, the presence of the fixed mullion makes it diflicult to install the bafl'le in heat conducting engagement with the heating element portions, particularly because of dimensional variations which are inherent in the evaporator and other refrigerator Components. Through use of the present iuvention, it is possible to assure excellent heat transfer to the baffle despite the fact that there may be no physical contact between the bafile and heater.

Thus, in view of the foregoing, it is an object of the present invention to provide an improved defrosterheater and baffle installation for a refrigerator, particularly a two door refrigerator.

More specifically, it is an object of the present invention to provide a defroster-heater installation in which a heater is provided near a bafile and means is provided on the baffle for holding water in heat transfer relationship with the baflle and heater.

A further object of the present invention is to provide a heater-bafiie installation in a two door refrigerator in which the baflle can be installated in excellent heat transfer relationship with the heater despite the fact that physical contact with the heater may be very limited, or no physical contact may be possible.

Still another object of the present invention is to provicle a defroster-heater and bafiie installation in which the heater may be placed in thermal relationship with the baffle despite the fact that the baifie must be raised into position beneath the heater rather than slid into position adjacent the heater.

A particular advantage of the present invention is the provision of a heater and bafiie arrangement in which heat transfer to the baffle can be successfully accomplished despite the fact the heater is spaced from the bafile.

The novel features that are considered characteristic of the invention are set forth in the appended claims; the invention itself, however, both as to its organization and operation, together With additional objects and advantages thereof will best be understood from the following description of a specific ernbodimentwhen read in conjunction with the accornpanying drawings, in which:

Figure 1 shows a front elevational view of the top portion of a two door refrigerator in which the present invention finds particular utility;

Figure 2 shows aside elevational view of the refrigerator taken on plane 2'-2 of Figure l, a part of the side wall being broken away to facilitate illustration of the interior construction;

Figure 3 is a perspective view of the refrigerator bafile in thermal relationship with two portions of a defrosterheater, the heater being shown diagrammatically;

Figure 4 isv a cross sectonal view of the top cover of the bafiie with a juxtaposed heater portion taken on plane 4-4. of Figure 3; and' Figure 5 is an enlarged cross sectional view taken on plane 5-5- of Figure 3 showing a portion of the defroster-heater partially disposed within a baffle cavity which contains defrost water forming a heat transfer medium between the heater and baffle.

As illustrated in Figures 1V and 2, the preferred embodiment of the present invention includes a refrigerator cabinet, generally indicated 1, which is provided with an inner liner 2 which defines an upper freezer compartment 3 and a lower food storage compartment 4. A fixed mullion, or barrier Strip, 5 extends between the side walls of the cabinet and forms, in conjunction with breaker strip 6, a seating area for gaskets 7 and 8 of upper and lower access doors 9 and 10 which permit access to

compartments

3 and 4, respectively.

A conventional refrigerant evaporator 11 is provided within the freezer compartment, which compartment is defined in part and bounded by a removable baffie 12 which is disposed largely behind mullion 5. Batfie 12 is supported at its rear by a pair of adjustable eccentrics 13 which are Secured to the side walls of the cabinet. At its front, the baffle is supported by a pair of Swingable brackets 14 which are also attached to the cabinet side walls and are swingable forwardly to release the front end of the bafiie so that it can be dropped and the baflie slid off of the eccentrics and out through the lower access opening of the refrigerator.

The Structure for mounting the bafiie and adjusting it vertically is described and claimed in application Serial No. 258,665, filed on November 28, 1951, in the name of Robert A. Iansen, and entitled Baflle Mounting Means For Refrigerator. The present application does not concern directly the physical Structure per se for mounting the baffle. i

To remove frost which has accumulated on the evaporator, a sinuous electrical resistance type defroster-heater element 15 is Secured directly beneath evaporator 11, as by clips 16. A time clock control, indicated at 17 in Figure l, is provided in series with therrnostats and the other control elements (not shown) to periodically supply heating element 15 with electrical energy whereby the heater will be raised in temperature and melt the frost from the evaporator. The Specific details of the control System constitute no part of this invention and are described and claimed in Patent 2,601,466, issued on June 24, 1952, in the name of B. D. Thomas, and entitled Defroster Circuit.

The specific type of heater does not constitute a limitation of the present invention and it should be understood that any defroster-heater positioned and functioning, as does heater 15, can be used in accordance With the teaching of the present invention.

In the preferred embodiment of the present invention, two forwardly and rearwardly extending portions, 18 and 19 of heater element 15, are formed closely adjacent to the baflle. These portions are spaced from the evaporator (Figure 2) to compensate for the spacing between the bafiie and evaporator. It will be appreciated by those skilled in the art that heater 15 may, if desired, be a continuous heater in which

portions

18 and 19 are merely integral parts, or the heater may be made in sections according to the particular design requirements of the refrigerator.

The baffle itself has been shown in Figure 3. It will be noted that the baffie is formed with a heat conductive top cover Zil, which may be made from aluminum, and a lower plastic portion 21 which are joined together, as by screws 22. As illustrated in Figures 3 and 4, cover 29 is formed to define a pair of shallow forwardly and rearwardly extending enclosed cavities 23 which are positioned opposite and directly beneath

heater portions

18 and 19. Cover is also formed to define a channel 24 which directs drip water collected by the bafile to an outlet funnel 25, as described more fully in the beforementioned Cochran patent.

Because of the presence of mullion 5, it is not feasible to slide bafie 12 into position beneath

heater portions

18 and 19 with a simple rearward motion and thus thermal-frictional engagement between heater portions and the baflie cannot be attained through sliding contact. Instead, the baffle is raised into position adjacent the defroster-heater portions and behind the mullion. Because of dimensional variations in the refrigerator components made in mass production, there is no guarantee that the heater will always be brought into direct physical engagement with the cover of the baflle. Should too much physical interference be encountered, the batfie would be difficult or impossible to install. Should the heaters be spaced too far away from the baflie, there would be insufficient heat transfer to the baflie.

The cavities or wells 23 formed in the cover 20 of the baffle solve this difficulty since an appreciable amount of defrost water 23a will collect within the cavities during the first part of the defrosting cycle and wet the adjacent heater portions to form a heat transfer medium or means between the heater and the bafiie cover. The heater portions project inside the wells (see Fig. 5 Thus, although point contact between the heater and the bafie, as at 26 (Figure 4) is not undesirable, such contact is not necessary, and effective defrosting of the baffle can be attained so long as the heater portions are sufiiciently close to the bafle so that they are wet by the water in the cavities.

The cavities are defined by surrounding ridges 27 raised above the surface of the baffle cover. Each cavity preferably has a bottom 28 which slopes gradually upwardly from front to rear to favor Collection of a pool of water near the front where there is the greatest possibility that the heater portions will be spaced from the baffle. The eccentrics 13, being adjustable, make possible vertical adjustment of the rear of the baflile to assure close proximity to the heater portions, but the brackets 14 do not permit adjustment at the front of the baffle.

Since the cavities have a depth of approximately 3/1 of an inch near the front of the baffie, it will be apparent that significant dimensional variations of the refrigerator components can be tolerated without jeopardizing the possibility of water within the cavities forming a heat transfer medium with the heater portions. This being the case, it will be apparent that the present invention not only makes possible effective baffle defrosting but also Simplifies overall assembly of the refrigerator Components as well as installation of the bafile itself within the refrigerator cabinet.

In view of the foregoing description of the present invention, it will be appreciated by those skilled in the art that an improved installation for providing heat transfer froma defroSter-heater to a refrigerator bafiie has been provided and one in which the effective heat transfer can be attained despite the fact that no physical contact can be Secured between the heater and bafle.

Having described a preferred embodiment of my invention, I claim:

- 1. A defroster-heater-bafiie installation for a two door refrigerator including a cabinet having a fixed horizontal mullion extending between its side walls, a bafile positioned behind said mullion and supported by the side walls of the cabinet, an evaporator within the cabinet and above said baffle, a defroster-heater Secured to said evaporator and having a portion spaced therefrom, said baffie being formed to define a shallow well positioned adjacent said defroster-heater portion, said defrosterheater portion extending within the space defined by the baflle well.

2. In combination, a refrigerator cabinet, an evaporator within said cabinet, a defrost water collecting and thermal insulating bafiie Secured to said cabinet beneath said evaporator, a defroster-heater Secured beneath said evaporator, said heater having a portion spaced from said evaporator in juxtaposition with said bafile, said bafe being formed to define a well adjacent and surrounding said defroster-heater portion whereby defrost water from said evaporator will collect within the well and form a heat transfer medium between said heater and said baffle.

3. In combination in a refrigerator having an evaporator on which frost is formed during operation of the refrigerator and from which the frost is melted periodically to form defrost water, a defrost water collecting member, and a heater having at least one portion thereof closely adjacent said defrost water collecting member, said member defining a well surrounding said heater portion for holding defrost water in contact with said heater portion forming a heat transfer path between said heater portion and said water collecting member.

References Cited in the file of this patent UNITED STATES PATENTS Hill Dec. 6, 1932 Harper Aug. 27, 1940 Krackowizer Feb. 10, 1942 Becker Mar. 17, 1942 Baker Oct. 29, 1946 Davis Nov. 4, 1947 Frie Mar. 1, 1949 Rickert May 1, 1951 Cochran Apr. 8, 1952 McCloy May 27, 1952 Thomas June 24, 1952