US3380615A - Refrigeration apparatus cabinet construction - Google Patents

Description

April 30, 1968 M. H. KESSLER 3,380,615

REFRIGERATION APPARATUS CABINET CONSTRUCTION Filed Nov. 17, 1965 United States Patent 3,380,615 REFRIGERATION APPARATUS CABINET CONSTRUCTION Michael H. Kessler, Grove City, Ohio, assignor to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Nov. 17, 1965, Ser. No. 508,223 9 Claims. (Cl. 220-9) ABSTRACT OF THE DISCLOSURE Refrigerator cabinet construction of the type having foamed-in-place thermal insulation including breaker Strip means having opposite, substantial width, forked margins which fit with correspondingly dimensioned edge constructions on the liner and shell to formed enclosed overflow spaces to accommodate leaking of the expanding foam into the overflow spaces.

This invention relates generally to a cabinet construction for refrigeration apparatus such as domestic refrigerators and freezers, and relates particularly to a thermal breaker strip arrangement well suited for use in refrigerating apparatus having foamed-in-place plastic insulating material between the shell and liner walls of the cabinet.

While the application of the invention is not limited to foamed-in-place refrigerator cabinets, its charatcer eminently suits it for such use and accordingly the invention will be principally described in that connection.

One technique in making foam insulated cabinets calls for expanding the foam-in-place between the cabinet liner and shell walls and into direct and adhering contact with the thermal breaker strip which seals the gap between the front edges of the liner and shell. In employing this technique, it is highly desirable that the seal between the breaker strip and the edges of the liner and shell be adequate to minimize the escape of the expanding foam onto finished surfaces so that foam cleanup is unnecessary, or relatively limited. While certain steps may be taken to facilitate the cleanup operation, substantial cost savings can be effected if the cleanup is restricted to predetermined areas and reduced to a minimum.

Accordingly, one object of this invention is to provide a cabinet having a thermal breaker strip and mounting arrangement therefor which permits foam to be expanded directly against the breaker strip without undue leakage occurring.

Another object is the provision of a cabinet construction in which the breaker strip not only provides an effective seal but additionally is constructed to enhance the appearance of the cabinet and carries out the prevailing squarecorner, straight-line appearance theme.

Another object is the provision of a breaker strip which is reasonably easily assembled to other components of the cabinet, and which does not require special fastening brackets.

I attain these and other objects of the invention by providing, in a refrigerator cabinet construction of the type having an outer shell incasing a nested inner liner, an inwardly-open channel at the edge of the shell, an outwardly-directed flange at the front edge of the liner, and a breaker strip of special configuration for covering the space between the edges of the liner and shell. The strip has opposite longitudinal margins which are forked in transverse section. One forked margin engages the liner edge in overlapping and gripping relation, and the other forked margin is engaged and gripped by the shell channel. The presently preferred construction includes opening the legs of each fork to provide a space bounded by the legs and the engaged part suflicient to accommodate ex- 3,380,6l5 Patented Apr. 30, 1968 'ice panding foam which leaks into the forked space. The strip is also sized so that it must be deflected sufiiciently to be wedged into place that a tight frictional engagement exists between the strip and the shell and liner.

A preferred embodiment of the invention will be described in connection with the accompanying drawing, wherein:

FIGURE 1 is a partly-broken isometric view of a cabinet in which the shell, liner, and breaker strips are shown in exploded relation to each other;

FIG. 2 is a horizontal sectional view of the breaker strip corresponding to one taken along the line IIII of FIG. 1;

FIG. 3 is a fragmentary sectional view showing the breaker strip of FIG. 2 in installed relation to the liner and shell edges; and

FIG. 4 is a fragmentary, partly-broken and exploded, isometric view showing a typical corner arrangement of the breaker strips, and the joint and cuff arrangement between a side strip and bottom strip.

The refrigerator cabinet parts shown in FIGURE 1 include the open-front shell 10, the open-front liner 12 which is supported by and nested in the shell, and the break strip means 14 shown in the assembled form of a collar which seals the gap between the liner and shell edges. The portions of the liner and shell of particular interest with respect to this invention are their perimetric edges which define the gap to be sealed by the breaker strip means and, accordingly, attention will now be directed to these edges of the liner and shell.

The front face of the shell, which generally frames the access opening to the interior of the cabinet, includes 21 depending top flange 16, opposite side flanges 18 and 20, and a lower front wall 22, the flanges and wall all lying in the plane of the cabinet access opening. The edge means of the shell adapted to be engaged by the breaker strip means to form the preferred seal according to the invention is formed by working the sheet metal at the inner edges of the side flanges 18 and 20 to form inwardlyopen channels which face each other across the open front of the shell. As best shown in section in FIG. 3, the channel includes a retroverted leg 24, a web 26, and an opposite leg 28, all of which extend for substantially the height of the front access opening. The bottom edge 30 of the top flange 16 (FIGURE 1), and the top edge 32 of the lower front wall 22, may have the same channel form as the shell side edges or, if tool cost considerations dictate against a channel, may simply be bent over to form a double thickness edge.

The front face of the liner 12 is recessed rearwardly from the front face of the shell 10 when the liner is located in its final installed position within the shell. The channel extending around the forward edge of the liner may conveniently be formed as an integral part of the liner walls 34 by simply bending the forward edge as shown in section in FIG. 3. The forward edge includes an outwardly-directed flange 36 lying at substantially a right angle to the liner side wall, and a rearwardly-directed leg 38 lying substantially at a right angle to the flange 36. Thus the liner edge channel is rearwardly-open to the space between the liner and shell walls.

The breaker strip means may be molded as four separate pieces which together form a collar (FIGURE 1). The two side pieces 40, and the top and bottom pieces 42 are connected during installation with the joints being hidden after installation by the cuffs 44 located at the top and bottom ends of the straight side pieces 40.

The presently preferred material of which the breaker strip means is molded is a modified high impact styrene commonly termed ABS, which designates an acrylonitrile-butadiene-styrene plastic. Two specific examples of ABS plastics which are satisfactory for use with foamed- -in-place poiyether-urethane plastic are the Monsanto Com panys Lustran or -LNI710 material, and the United States Rubber Companys Naugatuck MV" material. These materials possess the properties of sufficient toughness and flexibility to withstand the effect of the reaction of the foam being expanded in place and directly against the obverse face of the breaker strips. Of course the breaker strips are supported against displacement from the pressure generated by the foam.

The transverse cross-section of a side breaker strip 40 is shown in FIG. 2. The strip is molded so that the opposite longitudinal margins are fork-shaped in transverse section. As installed, the right forked margin 46 is adapted to engage the liner channel as shown in FIG. 3, and the left forked margin 48 engages the shell channel, with the intermediate part of the breaker strip designated 50 occupying the remainder of the gap between the shell and channel edges.

The liner-channel-engaging fork 46 includes a pair of spaced apart legs 52 and 54 having a dimension between their inner surfaces which is slightly less than the breadth of the liner channel. Thus, while these legs extend substantially parallel to each other before being pressed into engagement with the liner channel, they spread apart and tightly engage the outside faces of the liner channel in tight frictional engagement when the fork 46 is forced onto the liner channel. The free end 56 of the leg 54 is flared to facilitate installation of the breaker strip.

The forward forked margin 48 of the breaker strip includes a front facing leg 58 which has an offset tongue 60 at its free end. The other leg 62 of the fork 48 extends at an acute angle from the leg 58. The offset tongue 60 locks in against leg 24 of the shell channel as installed so that the forward face of the leg 58 constitutes a substantially flush continuation of the front face 18 of the shell. The angle between leg 58 and breaker web 50 preferably approximates a right angle so that the breaker design contributes to the theme of square corners and rectangularity to enhance the appearance of the front face of the cabinet.

To install a side breaker strip 40, the rear fork 46 is first pushed in place over the liner channel with the legs 52 and 54 overlapping the liner channel. As may be seen in FIG. 3, the legs 52 and 54 are sprung outwardly from each other from their normally unstressed parallel position. The breaker is pushed rearwardly on the liner channel a sufliicent distance that the forward fork leg 62 may be swung down into the shell channel, and the forward leg 58 of the front fork may be pushed into place with the tongue 60 pressing forwardly against the retroverted leg 24 of the shell channel. As thus seated a relatively tight seal to minimize the escape of the expanding foam is provided along each of the lines of engagement between strip and channels. The lines along which the tightest engagement is experienced where the rear fork 46 engages the liner channel are indicated by the numerals 64 and 66 while the lines 68 and 70 indicate the lines of tightest engagement of the front fork 48 with the shell channel. The broken line arrows in FIG. 3 indicate the direction of movement of the expanding foam insulation material.

It will be appreciated that the space defined between the legs of the forked margins and the respective channels they engage provides a substantial volume overflow chamber in which leaking foam which passes by the points 66 and 68 may expand without readily escaping further beyond the pressure points 64 and 70. As a result, clean-up of foam leakage after the foaming-in-place is completed is held to a relatively low level. The depth of the space in margin 46 also provides the leeway which permits snapping the breaker strip in place.

A lapping joint structure is provided at each end of the side pieces to mate with the complementary ends of the top and bottom pieces. As shown in FIG. 4, a raised cuff 44 and an inset tongue 72 are molded as an integral part at the end of the side piece. The mating end 74- of the bottom breaker strip 42 has a visible surface configuration conforming to the visible surface configuration of the side piece. The end 74 fits into the groove between the cuff 44 and '72 so that as assembled the end piece 74 of the bottom breaker strip appears as a continuation in contour of the side piece with only the cuff 44 overlying the joint. The forked margins may be omitted in the corner portion 76 of the bottom piece because of the practical difficulties encountered in forming cooperating channel portions at the corner locations of the shell and liner. Accordingly, sealing of the thermal breaker strip in these areas is principally accomplished by the use of special adhesive fillers. However, the bottom breaker strip 76 includes a forked rear margin 78 and a grooved front margin 80 for most of the width of the cabinet. The transverse cross-sectional configuration of the bottom and top strips of course may be same as the side strips if it is determined to be expedient to do so from a manufacturing cost standpoint. In any event, where liberties are taken in departing from the preferred cross-sectional shape of the side pieces, the leakage problem will be principally confined to these areas, and accordingly, the cleanaip problem of leaking foam insulation is mostly restricted to these areas.

It will be appreciated that with the breaker strips being cammed into place as described, they will hold their position without the aid of other means such as clips or brackets in most cases. When used with foamed-in-place cabinets, the foam adheres to the hidden face of the strip so there is little chance of the strip coming loose without a purposeful removal. The advantages of being able to foam-in-place and directly against a breaker strip are manifold and more fully explained in the copending US. patent application Ser. No. 508,221 of Harold F. Simmonds filed contemporaneously herewith.

I claim as my invention:

1. Refrigeration apparatus cabinet construction comprising:

an outer shell;

a nested inner liner;

inwardly-open channel means of substantial dimension in a front-to-rear direction of said cabinet at the edge of said shell;

outwardly-directed flange means of substantial dimension in a side-to-side direction of said cabinet at the edge of said liner;

breaker strip means for covering the space between said edges, said strip means including opposite longitudinal margins, of forked configuration in transverse section, one of said forked margins gripping said flange means in overlapping relation, the other of said forked margins being received in said channel means in gripped relation;

a foam insulating material expanded in the hollow space between the walls of said shell and liner and into direct contact with said strip means;

said forked margins defining, with said channel means and said flange means, respectively, overflow spaces out of open communication with the hollow space between the Walls of said shell and line, said overfiow spaces being of adequate volume to accommodate substantial expansion of said foam leaking into said overflow spaces from the hollow space between the walls of said shell and liner during the expansion of foam therein.

2. A construction according to claim 1 wherein:

said flange means forms one leg of a rearwardly-open liner channel on said liner edge, said liner channel opening into the space between the walls of said liner and said shell.

3. A construction according to claim 1 wherein:

said one and said other of said forked margins are disposed generally at right angles to each other.

4. A construction according to claim 2 wherein:

the depth of said liner channel exceeds the depth of said one forked margin in a relaxed state so that said one forked margin is deflected toward an open position in seating on saidliner channel.

5. A construction according to claim 4 wherein:

the depth of said shell channel is less than the depth of said other forked margin at its open extremity so that said other forked margin is deflected toward a closed position in seating in said shell channel.

6. A construction according to claim 5 wherein:

said other forked margin includes a forward leg having a rearwardly-offset portion adapted to nest with the front leg of said shell channel so that the remainder of said forward leg lies substantially flush with the forward face of said shell.

7. In a refrigeration cabinet of the character including an open-face outer shell and an open-face nested inner liner having foamed-in-place insulating material in the wall space between the shell and liner;

an inwardly-open channel extending along at least two sides of said shell and immediately behind the front face of said shell;

a rearwardly-open channel extending along the side edges of said liner at its front face, and immediately outside of the plane of the side walls of said liner; and

breaker strip means to close the gap between said channels, said strip including one and an opposite edge of forked configuration in transverse section said one fork overlapping said liner channel in tightly gripping engagement, and said other fork being received into said shell channel in tightly gripped engagement thereby.

8. In a refrigeration cabinet according to claim 7:

said forks of said strip define, with said channels, an overflow space of adequate volume to accommodate substantial expansion of said foam leaking into said space.

9. In a refrigeration cabinet according to claim 7:

said breaker strip means comprises an ABS" plastic material.

References Cited UNITED STATES PATENTS 2/1959 Allen 220-9 8/1966 Crowe 220-9

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