|Publication number||US3794396 A|
|Publication date||Feb 26, 1974|
|Filing date||Jun 21, 1972|
|Priority date||Jun 21, 1972|
|Publication number||US 3794396 A, US 3794396A, US-A-3794396, US3794396 A, US3794396A|
|Original Assignee||Gen Electric|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (6), Referenced by (10), Classifications (7)|
|External Links: USPTO, USPTO Assignment, Espacenet|
1 1 Feb. 26, 1974 4] REFRIGERATOR CABINET CONSTRUCTION Leonard L. Vick, Louisville, Ky.
 Assignee: General Electric Company, I
22 Filed: June 21,1972 21 1 Appl. N .1 264,939
I  References Cited UNITED} STATES PATENTS 3,174,642 3/1965 Loewenthal et a1.. 220/9 F 3,265,783 8/1966 3,444,280 5/1969 Pulaski 264/45 3,152,199 10/1964 Roberts...
1,759,723 Weldl 220/9-R FOREIGN PATENTS OR APPLICATIONS 691,149 7/1964 Canada 220/9 F Primary ExaminerPaul R.' Gilliam Attorney, Agent, or FirmWalter E. Rule; Francis Boos, Jr.
 I ABSTRACT A refrigerator cabinet including insulated walls comprising a plurality of sheet members collectively forming the spaced case and liner surfaces of the walls. In the joints or seam areas in' which edge portions of adjacent sheet members overlap, the edge portion of one of the members is provided with corrugations running parallel to the sheet member edge. These corrugations and the overlapping surface of the adjacent sheet form a plurality-of parallel passages extending transversely of the path of any foam flow into the joint which permit the expansion of foam therein to prevent leakage of foam through the joint. I
4 Claims, 3 Drawing Figures REFRIGERATOR CABINET CONSTRUCTION BACKGROUND OF THE INVENTION The present invention relates to foam insulated refrigerator cabinets and similar insulated structuresand more particularly to refrigerator cabinets in which the foam insulation is formed in place within the walls of the cabinet and serves to structurally bond the sheet members collectively forming the wall surfaces into a unitary structure.
' Foam insulated refrigerator cabinets include a plurality of sheet members collectively forming the spaced case and liner surfaces of the walls with the space between the liner and case being filled with foamed-inplace resin insulation. For example, the outer case may comprise a sheet metal member forming the sideand top walls of the outer case and a second sheet metal member forming the back wall of the case while the cabinet liner may be a fabricated metal or plastic member. These members are assembled in a suitable foaming mold or fixture and fluid or frothed foamable insulation is introduced into the space between the outer case and liner components. It is essential that the seal between adjacent edge portions of the members be adequate to prevent the escape of expanding foam onto the outer finished surface of the members. Known methods for preventing the foam escape have included the use of resilient foam seals in the joint or seam areas as described, for example, in U.S. Pat.'No. 3,174,642- Lowenthal and U.S. Pat. No. 3,444,280-Pulaski. An-
other sealing approach has included the use of glass fiber bats or strips as described, for example, in U.S. Pat. No. 3,265,783-Jacobs, U.S. Pat. No. 3,512,323- Hupfer and U.S. Pat. No. 3,516,566-FranckfWhen the cabinet includes breaker strips bridging the space between the case and liner, specially designed breaker strips have been employed for preventing foam migration from the interior to the exterior surfaces of the cabinet as described, for example, in U.S. Pat. Nos. 3,380,6l5-Kessler and 3,633,783-Aue. I
The use of special sealing strips or bodies of resilient foam plastic or glass fiber increases the number of operations required in the manufacture of the cabinet and hence increases the cost of the finished cabinet. The present invention is directed to an improved construction in which the overlapping edge portions of the case and/orliner members of the cabinet are formed to provide adequate sealing of the foaming insulation thereby eliminating the need forspecial or additional sealing means.
SUMMARY or THE INVENTION,
In accordance with the illustrated embodiment of the present invention, there is provided a refrigerator cabinetincluding two ormore sheet members collectively forming the spaced outer and inner walls of the cabinet and an insulating body of foamed plastic formed in situ between the case and liner components, this insulating body preferably also providing the principal means for the overlapping edge portion of at least one of the members. These corrugations form a plurality of parallel spaced ridges generally contacting the face of the edge portion of the other member while the spaces or valleys between the ridges form passages running generally transversely of the path of any foam leaking into the joint area in which any leakage foam expands and hardens or sets before the foam can flow entirely through the joint. In accordance with a specific'embodiment of the invention, a sheet metal member forms the side and top walls of the case and is provided with inwardly extending flanges along the rear edges thereof for overlapping engagementby a second sheet metal member forming the back wall of the case. The inwardly extending flanges are corrugated longitudinally and this corrugated structure, in combination with the back wall member, forms the above-described ridges and passages providing a foam seal between the two members. In accordance with another aspect of the invention, similar corrugated flanges along the front edges of the member forming the side and top walls of the case overlap outwardly extending flanges of a plastic liner to form similar foam seals.
BRIEF DESCRIPTION OF THE DRAWING DESCRIPTION or THE PREFERRED EMBODIMENT With reference to FIG. 1 of the drawing, the illustrated refrigerator cabinet includesan outer surface or case 1 and an inner surface of liner 2 which are spaced from one another with the space between the two being filled with polyurethane resin insulation. Typically, the case 1 is made of sheet metal and comprises a first sheet metal member 3 bent to form the side and top walls of the case and a second sheet metal member 4 (FIG. 2) forming the rear wall of the case. The liner 2, at the time of assembly within the case 1, usually comprises a unitary or fabricated member and, in the illustrated embodiment of the invention, the liner2 is a one-piece plastic structure that is adapted to nest within the case and includes an outwardly extending from flange 5 at the front thereof surrounding the access opening to the storage compartment defined by the liner 2.
In the manufacture of such cabinets, the components of the case andtheliner are supported within a suitable foaming fixture in their final spaced relationships, the fixture serving to support these components or members against the foam pressure during expansion and curing of the foam insulation 6. Such a fixture, as illusplates, such as plates 11, for supporting the opposite side walls 12 and 14 of the case. Plate 15 and 16 re-' spectively support the liner side and rear walls, and a tion resilient foam gasket means,.glass fiber gaskets,
tapes, plastic sealants or pads have usually been employed in the joint areas between adjacent edges of the members forming the surfaces of the insulated cabinet structure for preventing the escape or leakage of foam through these areas.
In accordance with the present invention, the joints or seams exposed to the direct contact of the foaming resin insulation are so formed as to provide seals preventing the leakage of foam through such joints and seams without the use of additional sealing means. This result is obtained by overlapping the edge portions of adjacent sheet members and providing one of the overlapping edge portions with a corrugated surface pattern which in cooperation with the facing surface of the edge portion of the other member forms a plurality of expansion zones in which any foam leaking into the joint area is allowed to expand and cure to a higher vis cosity or to the solid state before reaching the next succeeding passage.
The invention is illustrated in FIGS. 2 and 3 of the drawing in its application to the joint areas along the rear and front edges of the sheet metal member 3 forming the top and opposed side walls 12 and 14 of the casing. These edges are formed to include inwardly. extending flanges l9 and 20 corrugated lengthwise or longitudinally thereof. When assembled in the foaming structure with the back wall member 4 in position contacting the flanges 19, the edge portions of the back wall member 4 in engagement with the flanges 19 provide for longitudinal contact between the two edge portions along the ridge areas 21 of the corrugated flange thereby forming a plurality of linear contact areas between the two edge portions. The valleys 22 between the ridge portions 20 form a plurality of parallel passages 24 extending transversely of the flow of any fluid foam leakage during the foaming operation. Such leakage foam will expand in these passages and cure to a more viscous or solid state before reaching the next ridge.
It will, of course, be appreciated that continuous linear contact of the ridges 21 with the edge portion of the sheet 4 cannot be obtained in any joint and, accordingly, some foam leakage will usually take place outwardly through the joint past the first and in some cases the second ridge. However, the leakage which does occur past any ridge is accompanied by a definite pressure drop of the foam across the ridge or, more specifically, from corrugation to corrugation. This pressure drop promotes expansion of the foam in the passage and loss or escape of the blowing agent. Loss of blowing agent and curing of the polyurethane resin are also accelerated by contact with the warm metal flanges 19 and 20. The result is that the foam will have a higher viscosity and hence a greater flow resistance by the time it reaches the next ridge. Once the foam has set or hardened it forms a-complete barrier to further leakage. Thus, by providing a plurality of passages 22 ex- 4 tending transversely of the path of any foam leakage, foam migration through the joint or seam will be limited to the first few passages and hence cannot migrate entirely through the joint area to the exterior of the cabinet.
The corrugated flange 20 at the forward edge of the sheet member 3 performs a similar function in cooperation with the outwardly extending flange 5 of the liner 2. In this portion of FIG. 3 of the drawing, the first of the ridges 21a to be contacted by foam is illustrated as being spaced a slight distance from the inner surface'or facing surface of the flange 5. As the foam flows into contact with this joint area, relative fluid foam will easily migrate past the first ridge 21 and into the first passage 22. Some increase in viscosity of the foam takes place during the time the first passage 22 is being filled so that by the time the foam reaches the second ridge 21b, its higher viscosity and the better contact of this ridge with the flange 5 will decrease the foam flow rate to the point where complete solidification of the foam will take place before the second of passages 22 has become completely filled with foam.
An additional advantage to the present invention is the fact that the various components of the cabinet structure can be bonded together solely by the adhe' sion of the foamed mass to'the inner surfaces thereof. Accordingly, it is not necessary to weld or otherwise secure the back plate 4 to the rear flanges 19 since the foam adhering to these members rigidly joins the back plate to the side and top walls of the casing. Similarly, the foam adhesion to the liner and the inner surfaces of the casing adjacent the forward or face portion of the cabinet rigidly bonds the liner to the casing, this bonding being reinforced by the limited foam leakage into the joint area between theflange 20 and the flange 5.
It will be obvious, of course, that since the expanding foam first engages the inner surfaces of the flanges 19 and 20, that is, the surface 25 of the flange 19 and the surface 26 of the flange 20, the pressures generated by the expanding foam will also serve to press these flanges into closer engagement with either the back plate 4 or the liner flange 5 thereby obtaining better contact between the ridges 21 and their facing surfaces and further restricting any spaces between-the ridges and the opposing surfaces through which the leaking foam might pass.
a While there has been shown and described a specific embodiment of the present invention it will be understood that it is also applicable to other insulated wall structures and it is intended by the appended claims to cover all such modifications as fall within the true spirit and scope of the invention.
1. A structure comprising an insulated wall defined by spaced wall surfaces and an insulating body of foamed resin formed in situ' between said surfaces;
said surfaces including at least two surfaces forming members having overlapping edge portions forming a joint contacted by the resin during foaming thereof;
the face of one of said overlapping edge portions having longitudinally extending corrugations forming a plurality of parallel spaced ridges generally but not continuously contacting the face of the other edge portion and a plurality of spacesbetween said ridges; migration of .the foaming resin past the ridges contacted thereby being limited to the first a resin foam insulating material expanded in situ in the space between said outer and inner surfaces into direct contact with said edge portions;
said corrugations providing a plurality of ridges in substantially but not continuous contact with said adjacent member edge portion and a plurality of passages extending transversely of the path of expanding foam entering said joint; the penetration of expanding foam into said joint being limited to the first few of said passages.
4. A cabinet according to claim 3 in which said one member is made of sheet metal.
|Cited Patent||Filing date||Publication date||Applicant||Title|
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|Citing Patent||Filing date||Publication date||Applicant||Title|
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|US6560842 *||May 19, 2000||May 13, 2003||Specialty Equipment Companies, Inc.||Method of manufacturing a deli-style display case|
|US20120037642 *||Aug 10, 2011||Feb 16, 2012||Samsung Electronics Co., Ltd.||Refrigerator|
|DE19654048A1 *||Dec 23, 1996||Jun 25, 1998||Fritz Hakemann||Behälter mit durchgehender thermischer Zonengrenze|
|DE19654048C2 *||Dec 23, 1996||Mar 25, 1999||Fritz Hakemann||Doppelwandiger Behälter mit einer Innenwand und einer Außenwand aus einem thermisch gut leitenden Material, insbesondere für Kühlschränke und Wärmeschränke|
|U.S. Classification||312/406.2, 220/592.1, 220/902|
|Cooperative Classification||Y10S220/902, F25D23/064|