US2703442A - Refrigerator door - Google Patents

Description

March 8, 1955 L. A. PHILIPP REFRIGERATOR DOOR 2 Sheets-Sheet 1 Original Filed Sept. 22, 1948 fl// v e if ,7 ///W///,/

N m4 aw I m .m r 4 w w R w H k March 8, 1955 A. PHILIPP 2,703,442

REFRIGERATOR DOOR Original Filed Sept. 22/1948 2 Sheets-Sheet 2 FIG-4 IN V EN TOR.

United States Patent REFRIGERATOR DOOR Lawrence A. Philipp, Detroit, Mich., assignor to Nash- Kelvmator Corporation, Detroit, Mich., a corporation of Maryland Original application September 22, 1948, Serial No. 50,472. Divided and this application October 15, 1949, Serial No. 121,549

3 Claims. (Cl. 2035) This invention relates generally to refrigerators and particularly to freezing compartment doors therefor.

The present invention is a division of my co-pending application Serial No. 50,472, filed September 22, 1948, now Patent Number 2,613,509, patented October 14, 1952, for Refrigerating Apparatus.

In the manufacture of present day refrigerators, the access doors therefor are generally of composite construction comprising a front metal casing and a separate rear panel. The casing and panel together form a door shell wherein suitable heat insulation is usually provided to decrease heat leakage through the door. This type of door is economical to build, but where they are used for closing low temperature or freezing compartments, frost collects within the door and materially impairs the efliciency of the insulation. The frost results primarily from moisture laden room air leaking into the door through a clearance aperture provided therein for the door latch and possibly through the joint between the casing and the rear panel. In any event, the collection of frost on the door insulation is objectionable and to seal the doors to make them air tight would be objectionable also since the cost of so doing would be prohibitive.

Accordingly, it is an object of my invention to provide economically manufacturable freezing compartment doors of a character such that frost will not collect on the door insulation.

Another object of my invention is to provide for a refrigerator freezing compartment, an improved, composite door of a character such that heat insulation with in the door will remain dry and free of frost without need of the expense of sealing the joints of the door parts or sealing the latch clearance aperture or both against entrance of moisture laden room air which tends to condense and freeze on the insulation.

Another object of the invention is to provide an improved freezing compartment door of such construction as to induce any moisture which may find its way thereinto to freeze out on the inner surface of the door back panel instead of collecting on the insulation.

Another object of the invention is to provide for collecting frost on a surface spaced from the door insulation and for draining of resulting frost water from the interior of the door on defrosting of the refrigerating system.

Another object of the invention resides in a cabinet door construction of a character to induce diffusion of water vapor from the relatively high vapor pressure area within a refrigerator door to the relatively low vapor pressure area at a low temperature cooling element or refrigerant evaporator in the cabinet.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a front elevational view of a refrigerator embodying features of my invention;

Fig. 2 is a fragmentary enlarged sectional view of the refrigerator, taken along the line 22 of Fig. 1;

Fig. 3 is a fragmentary, horizontal sectional view of the refrigerator, taken along the line 3-3 of Fig. 2;

Fig. 4 is a view similar to Fig. 2 showing a modification of the invention; and

Fig. 5 is a cross sectional view of the modified refrigerator, taken along the line 55 of Fig. 4.

2,703,442 Patented Mar. 8, 1955 Referring to the drawings and first to Figs. 1 to 3 inclusive, there is shown a household type of refrigerator having a cabinet, designated generally by the numeral 20, which may be of any suitable type and construction. The cabinet 20 may comprise, in general, a casing 22, a casing reinforcing frame 24, a liner or spacer 26, and a second liner or shell 28. The frame 24 is an upright structure which is supported by and within the casing 22 at the front of the cabinet and in turn supports the liners 26, 28. These liners 26 and 28 are supported by the frame 24 in vertical spaced relationship within the casing 22. As shown, the liner 26 is disposed immediately above the liner 28, but it will be understood that the positions of the liners could be reversed or they could be arranged side by side insofar as concerns the present invention. Interposed between the casing 22 and the liners 26, 28 is heat insulation 30 which may be fiber glass or any of the other suitable well-known types of insulation for decreasing heat leakage into the interior of the cabinet. Also, heat insulation 32 is provided between the adjacent bottom and top walls respectively of the liners 26 and 28 and may extend to the cabinet upright walls as a partition to separate the liners 26, 28 and decrease heat exchange therebetween.

The liner 26 retains the insulation 30 in place above the partition 32 and, in addition, defines a freezing compartment 34 in the upper region of the cabinet to receive a cooling element or low temperature refrigerant evaporator 38. Similarly, the liner 28 retains the insulation 30 and 32 in place and forms walls of a food storage compartment 36 below the partition 32.

In the front of the cabinet, access openings to the compartments 38, 36 are closed respectively by doors 40, 42. These doors 40, 42 may be hung on the cabinet by suitable hinges 44 which may be secured to the casing reinforcing frame 24 of the cabinet. In general, the evaporator comprises a sheet metal container 46 and an evaporator coil or conduit 48. The container 46 is of box-like shape and is preferably of a size to occupy substantially the entire upper compartment 34 of the cabinet. In the present disclosure, the evaporator coil 48 is wrapped or wound about the container 46 in contact with the top, bottom and sides thereof for efficient heat trans fer between the parts. Flanged U-shaped clamps 50 may be used to clamp the evaporator coil 48 to the container top, bottom and side walls and these clamps may be provided with flanges which may be welded or be otherwise secured to the container walls. It will be understood that any suitable type of cooling element having a capacity (to effect freezing of foods and making of ice may be use An outturned flange 52 is provided on and extends around the front edge of the evaporator container 46 to receive and overlap with heat breaker strips 54 which close the space between the evaporator container 54 and the casing 22 at the front of the cabinet. portions of the breaker strips 54 engage in and are retained by channels 56 which are formed on and extend around the front edge of the cabinet casing 22.

Immediately beneath the evaporator 38, a pan 60 is provided which I arrange to function, among other things, as a water drip receiver during defrosting periods of the system. The pan 60 may be supported by the evaporator container 46 on the underside thereof or may be supported in any other suitable manner.

In the evaporator container 46, foods to be frozen or preserved at low temperature, ice trays etc. (not shown) may be stored. Because of the low temperature maintained by the freezing evaporator 38, I provide the insulation spacer or liner 26 of openwork material, such as wire screening, so as to allow moisture laden air, which may leak into the insulation, to pass freely through the insulation and screening into the freezing compartment 34 where the moisture freezes out on the evaporator 38 instead of collecting as frost on and decreasing the effectiveness of the insulation. The screen spacer 26 has a top, sides and back of which the sides and back extend down into the drip pan 60 which has the additional functions of supporting the screening and forming the bottom wall of the evaporator compartment 34. While I prefer to use a wire mesh-like spacer, it will be under- Outer marginal stood that one or more retainer strips, or a sheet material liner provided with apertures therein may be employed with substantially the same degree of effectiveness with respect to flow of moisture laden air to the evaporator.

The freezing compartment door comprises, a dish like front casing 62, and an inner or rear panel 64. The casing 62 and the panel 64 together form a closed door shell in which heat insulation 66 is provided throughout to decrease the rate of heat leakage through the door into the cabinet interior. Around its outer edge, the door casing 62 may be provided with an inturned flange 68 to reinforce the casing and to provide a seating surface for the panel 64 and for a door gasket 70. The flange 68 is preferably reinforced by a frame member 72 which may be welded or be otherwise suitable secured thereto. The gasket may be made of rubber or other suitably displaceable gasket material and is arranged on the door adjacent the outer peripheral edge thereof in position to engage the outer surface of the casing channel 56. Preferably, the door gasket 70 is of channel shape in cross section to receive and support therein an outer marginal portion of the door panel 64. The gasket 70 may be secured to the panel flange 68 by screws (not shown) or by other suitable securing means.

In the present construction, the door panel 64 is formed with a reduced central portion 74 thereof which when the door is closed projects inwardly into the evaporator opening defined by the breaker strips 54. This panel 64 is preferably made of a low heat conducting material, such as phenolic plastic. Because of the low temperature of the freezing evaporator 38, some frost will collect within the door 40 due to the condensation of moisture carried by warm room air which leaks into the door through such openings as the latch clearance aperture and possibly joints of the door parts.

In accordance with my invention, I provide an openwork spacer 76, preferably wire screening which I arrange to space the door insulation 66 from the inner surface of the central projecting portion 74 of the door so that moisture laden room air may pass through the interstices of this spacer 76 and collect as frost on the inner surface, as at 77, of the central panel portion 74 instead of on the insulation. By inducing the frost to concentrate on or near the central panel portion 74, condensate will flow down the inner surface of the panel without wetting the insulation, when the system is defrosted, and may drain from the door through a drain aperture 80 provided therein. This drain aperture 80 is provided in the door adjacent the bottom of the door panel 74.

The spacer 76 is formed with projections 84 to engage the door panel 74 so that a large portion of the spacer 76 is positioned slightly forwardly of the door panel. This provides insulation free space for the collection of moisture and formation of frost on the inner surface of the door panel portion 74. Also, the above mentioned space allows for free running of the condensate down the inner surface of the door to the drain 80 in defrosting of the system. The spacer member 76 may be made of suificiently strong and flexible wire such that it can be pressed into the panel projection 74 and be held in place by friction with the annular wall thereof and by the pressure thereagainst of the insulation 66 which has a tendency to expand.

Forwardly of and overlying the drain aperture 80, I provide a baflle 82 to prevent condensate draining from the door engaging or contacting the insulation 66. The baffle 82 extends entirely across the width of the door and may have a lower marginal portion thereof gripped and held between the inner and outer door flanges. Along its upper edge, the baffle member 82 may be attached to the spacer member or screen 76 by cement or by other suitable means.

The food storage compartment 36 may be refrigerated by the evaporator 38 by spacing the insulation or partition 32 from the liner sides to allow for air circulation between the food storage compartment and the evaporator, or a second evaporator may be used to cool the food storage compartment, either of which arrangement is well known in the art. For a more detailed description of the refrigerator, reference may be had to my above identified pending application.

Referring now to the modification shown in Figs. 4 and 5, the refrigerator cabinet shown comprises, in general, a frame 86, a sheet metal casing 88, a liner memher or spacer 90, and a liner member or shell 92. The liner member or spacer forms an upper freezing compartment 94 and the liner member or shell 92 forms a food storage compartment 96. Between the bottom and top walls respectively of the liners 90, 92, insulation 98 is provided and arranged to form a horizontal partition. Also, insulation 100 is provided between the liners and the casing 88 to decrease heat leakage into the interior of the cabinet. Any suitable well-known type of heat insulation may be used.

Within the freezing compartment 94, I provide a storage compartment forming container 102 which is preferably box-shaped having a top wall 104, bottom wall 106, end walls 108 and a rear wall (not shown). The container walls are spaced from the corresponding walls of the liner 90 to decrease heat exchange by conduction therebetween and to prevent, among other things, formation of frost and resulting wetting of the cabinet wall insulation 100. At the front of the container 102, outturned flanges 112 of the container top, bottom and sides receive and overlap with inner marginal portions of heat breaker strips 114. These heat breaker strips 114 have outer marginal portions thereof engaging in retaining channels 116 which may be formed out of the casing 88 around the outer periphery or front thereof. In addition to functioning as heat insulators between the casing 88 and the liners 90, 92, the breaker strips 114 give a finished appearance to the access openings of the freezing and food storage compartments. To insure against leakage of air into the cabinet insulation at the joints of the breaker strips 114 with the container flange 112, I provide a gasket 118 therebetween. The gasket 118 may be made of any suitable displaceable sealing material, such as rubber, and may be held displaced between the breaker strips 114 and the container flange 112 by self threading or sheet metal screws (not shown) or by other suitable means.

At the front of the cabinet, an upper door 120 is provided for closing the access opening to the container 102 and a lower door 122 is provided for closing the access opening to the food storage compartment 96. These doors 12.0, 122 may be hung on one side of the cabinet by suitable hinges (not shown).

The container door 120 includes a front casing 123, a rear or back panel 124 and insulation 125. Fiber glass or other suitable insulation may be provided in the door. The door back panel 124 is preferably formed with a reduced, rearwardly extending portion 126 which preferably has a concavo-convex, inner end wall 128. As shown in Fig. 4, the reduced portion 126 of the freezing compartment door 120 extends into the access opening defined by the breaker or finish strips 114. Preferably, the door projection 126 is formed with curved, top, bottom and side walls which in cooperation with the curved breaker strips 114 form a throat to decrease passage of cold air therethrough and consequently to decrease condensation on front surfaces of the cabinet, inwardly of the door gasket designated at 129. As shown, the door gasket 129 is attached to the door adjacent the outer peripheral edge thereof. Also, passage of cold air through the threat is decreased by the presence of the gasket 118 which in addition to its scaling function decreases the flow capacity of the throat.

The freezing compartment storage container 102 is refrigerated by a refrigerant evaporator 130 which may be of any suitable type. The evaporator 130 may be in the form of a coil or conduit 132 which may be wound around the container 102 in contact with the outer surface thereof for eflicient heat exchange between the parts. Spaced clips or other suitable means (not shown) may be used to hold the evaporator coil 132 against the outer surface of the container 102 and may be welded or be otherwise secured thereto.

In order to prevent condensation of moisture laden air and resultant frost on the door insulation, which tends to occur because of the close proximity of the freezing evaporator 130, I provide a frost collection space 134 in the door 120 and separate this space from the door insulation by a spacer panel 138. The panel 138 is located within the reduced portion 126 of the door and extends across the width thereof. Preferably, the spacer panel 138 is made of a heat reflecting material, such as aluminum foil, to reflect heat away from the frost collection space 134.

The panel 138 is spaced from the inner surface of the panel projection end wall 126 by spacer members or tubes 140. These tubes are vertically extending and horizontally spaced, as shown. The spacer tubes I140 may be made of rubber or other material which will readily conform to the contour of the wall I126. The tubes 140 are held in place by the aluminum foil spacer 1 38 and by the expansion force of the fiber glass door insulation which tends to expand against the tubes. As shown in Fig. 4, the readily formable aluminum foil panel 138 and the flexible rubber spacer tubes I140 readily conform to the convex, inner surface of the door panel.

A lower marginal portion 144 of the aluminum foil panel 138 curves forwardly and downwardly to engage and he held between the bottom flanges of the door casing and the door casing rear panel 128, within the channel of the door gasket 129 to avoid passage of Water into the insulation. Thus, the aluminum foil panel flange 144 serves also as a water bafile on defrosting of the system, to prevent wetting of the door insulation. The aluminum foil panel 138 is pressed into place so that the sides and top engage the corresponding surfaces of the reduced door portion but do not seal therewith so that air can pass from the region of the insulation 136 to the frost collection space 134. It will be seen that on defrosting, water will drain from the door through one or more drain apertures 146 provided in the lower flange or wall of the door panel.

From the foregoing description, it will now be understood :that l have provided improved, refrigerator freezing compartment doors of such construction as to maintain the door insulation dry, and free of frost, and thus maintain the high efiiciency of the insulation. It will be understood further that I have provided for keeping refrigerator door insulation dry and free of trost without sealing such doors against the entrance of moisture laden air and resultant expense of [the sealing operation. Also, in refrigerator doors I have provided for inducing collection of frost on a predetermined surfiace spaced from the door insulation where the insulation will not become frosted or 'wetted and whence water may be conveniently drained from the door. in addition, I have provided refrigerator doors of a character such that the interiors thereof are in open communication with evaporator-s so as to induce flow of moisture by diffusion out of the doors to cold suriaces such as [the surfiaces of an adjacent evap- 01 3101.

Although preferred and modified forms have been illustrated, and described in detail, it will be apparent to those skilled in the art that various other modifications may he made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1. A refrigerator door comprising, a casing, a rear upright panel on said casing having an inclined bottom wall, heat insulation interposed between said casing and said panel, a spacer interposed between said insulation and said panel spacing insulation from said panel to term a frost collection space, a drain in said inclined bottom wall, and a bafile on the opposite side of said drain from said upright panel.

2. A refrigerator cabinet door comprising, .a casing, a rear panel attached to said casing forming a door shell therewith, heat insulation between said casing and said panel, a sheet of material between said insulation and said panel, means spacing said sheet of material from said panel to effect an insulation tree space at the rear suriace of said panel for collection of frost, said sheet of material being pervious for flow of water vapor from the region of the insulation into said fro-st collecting space, a drain aperture in the bottom of said shell, and a Water baflie overlying said drain aperture and attaching said sheet material to said casing and panel.

3. A retrigerator door comprising, a casing having a rear inturned flange, .a normally refrigerated rear panel attached to said flange and cooperating with said casing to form a door shell, heat insulation within the door shell, a spacer member within the shell between said insulation and said panel, means formed out of said spacer member engaging the inner surface of said panel to space said space-r member therefrom and dorm .therebetween a frost collecting space, said spacer member being pervious to passage of water vapor from the region of the insulation .to the frost collecting space, 'a drain aperture in said panel adjacent the bottom thereof, and a water baflle member between said heat insulation and said frost collecting space to deflect drain water from the insulation and also attaching the lower edge of said spacer member to said panel and casing.

References Cited in the file of this patent UNITED STATES PATENTS 498,400 Lockstaedt May 30, 1893 2,084,883 AltCh-lSOIl June 22, 1937 2,190,954 Stickel Feb. 20, 1940 2,192,933 Saborsky Mar. 12, 1940 2,225,926 Oelmann Dec. 2 4, 1940 2,292,365 DeMore Aug. 11, 1942 2,304,757 Arthur Dec. 8, 1942 2,368,837 Hubacker Feb. 6, 1945 2,411,461 Philipp 'Nov. 19, 1946 2,449,384 Hursey et a1 Sept. 14, 1948 2,451,286 Heritage Oct. 12, 1948 2,497,713 Becker Feb. 14, 1950 2,515,892 Philipp July 18, 1950

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