Patent Description:
A method of making a cabinet for refrigerators and the like includes forming a liner and a wrapper having a periphery. The method further includes providing a vacuum insulated core that includes a filler material disposed inside a substantially impermeable envelope. The envelope is evacuated to form a vacuum inside of the envelope. The vacuum insulated core is folded to form a 3D core having a first wall and a second wall extending transversely relative to the first wall along a fold line. The 3D core is adhesively secured to the wrapper, and the liner is adhesively secured to the 3D core. The wrapper and the liner are sealed together at the peripheries thereof.

However, it is to be understood that the disclosure may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims.

With reference to <FIG> and <FIG>, a refrigerator <NUM> includes an insulated cabinet <NUM> having a fresh food compartment <NUM> and a frozen food compartment <NUM>. The fresh food compartment <NUM> can be accessed through access opening <NUM> by opening doors <NUM> and <NUM>, and the frozen food compartment <NUM> can be accessed through access opening <NUM> by sliding door/drawer <NUM>. The refrigerator <NUM> may include an ice/water dispenser <NUM> mounted to door <NUM>. The ice/water dispenser <NUM> may be connected to an ice box <NUM> formed in door <NUM>.

As shown in <FIG>, vacuum insulated cabinet <NUM> includes an external wrapper <NUM>, and a first liner <NUM> that is disposed within wrapper <NUM>. Liner <NUM> forms fresh food compartment <NUM>. A second liner <NUM> is also disposed within external wrapper <NUM>. The second liner <NUM> forms frozen food compartment <NUM>. The first and second liners <NUM> and <NUM> may be constructed utilizing substantially similar materials and processes. The external wrapper <NUM> may comprise sheet metal, and the liners <NUM> and <NUM> may comprise polymer materials. However, the wrapper <NUM> and liners <NUM> and <NUM> may be fabricated from a variety of materials as may be required for a particular application.

With further reference to <FIG>, cabinet <NUM> includes a vacuum core <NUM> that is disposed in a space <NUM> between wrapper <NUM> and liner <NUM>. As discussed in more detail below, vacuum core <NUM> may be adhesively secured to wrapper <NUM> by a suitable adhesive such as hot melt adhesive or two-sided adhesive tape <NUM>. A thin layer of adhesive <NUM> may be disposed in a gap "G" between vacuum core <NUM> and liner <NUM>. As also discussed below, adhesive <NUM> preferably has a low viscosity prior to curing such that liquid adhesive <NUM> flows into and fills gap G prior to curing.

With further reference to <FIG>, liner <NUM> may include chamfered or radiused corners <NUM> forming vertically extending inner corner spaces <NUM> between the liner <NUM> and vacuum core <NUM>. Vertically extending outer corner spaces <NUM> may be formed adjacent vertical spaces <NUM> adjacent edges <NUM> of vacuum core panels <NUM>. The vertically extending spaces <NUM> and <NUM> may be filled with polyurethane foam <NUM> that is substantially similar to polyurethane foam used in prior refrigerator cabinets that are not vacuum insulated. As discussed in more detail below in connection with <FIG>, the vacuum core <NUM> may optionally comprise a 3D structure that is formed from a generally flat blank by folding or other suitable process. If core <NUM> comprises a folded structure without edges <NUM>, vertical spaces <NUM> are not formed. If vacuum core <NUM> comprises a folded structure, the vertical spaces <NUM> may be smaller, or they may be eliminated as required for a particular application. Front edge <NUM> of cabinet <NUM> may comprise a separate insulated sealing member that interconnects wrapper <NUM> and liner <NUM>. Alternatively, the edge <NUM> may comprise overlapping flanges or the like that interconnect wrapper <NUM> and liner <NUM>.

With further reference to <FIG>, door <NUM> may include a front portion or panel <NUM>. The front panel <NUM> may comprise a vacuum insulated structure, or it may comprise a conventional refrigerator door structure having an outer door panel or wrapper <NUM>, door liner <NUM>, and polyurethane foam <NUM> disposed between the wrapper <NUM> and liner <NUM>. Door <NUM> includes an ice box <NUM> having a vacuum core 24A that is disposed between first (outer) and second (inner) ice box components. The vacuum core 24A is adhesively secured to first component <NUM> by a relatively thin layer of adhesive <NUM>, and vacuum core 24A is secured to second component by two-sided adhesive tape <NUM>, hot melt adhesive, or other thin adhesive. The ice box <NUM> and door front panel <NUM> may be fabricated separately, and the ice box <NUM> may be secured to inner surface <NUM> of front panel <NUM> utilizing interlocks (not shown) and/or adhesive.

With further reference to <FIG>, the vacuum core <NUM> may be formed from a blank <NUM> of core material that may be cut to remove corner portions 62A-62D. The core material <NUM> may then be folded along fold lines 64A-64D whereby flaps 66A-66D are folded upwardly relative to central portion <NUM> of core material blank <NUM> to form a 3D boxlike structure 60B as shown in <FIG>. The core material blank <NUM> may comprise porous core material such as fiberglass or other suitable material. After the 3D structure 60B is formed, the 3D structure 60B is then placed within an envelope <NUM> that is made from a non-porous barrier film. The non-porous film may comprise one or more layers of polymer, metal foil, or other such materials known in the art. Envelope <NUM> is substantially impervious to gasses such as nitrogen, oxygen, water vapor, carbon dioxide and other gasses. The envelope <NUM> is then sealed and evacuated to form a vacuum. Alternatively, the core material blank <NUM> may be cut to remove corner portions 62A-62D and placed within an envelope <NUM> prior to folding. The edges of the envelope <NUM> are heat sealed and envelope <NUM> is then evacuated to form a Vacuum insulated Panel (VIP). The VIP is then folded into the <NUM>-sided box shape shown in <FIG>. The sides and/or corners of the box may be taped in place to maintain the box shape.

As shown in <FIG>, the vacuum core <NUM> may be generally box-shaped as required to fit between wrapper <NUM> and liner <NUM>, or between components of ice box <NUM>, or between wrapper <NUM> and liner <NUM> of door <NUM>. The vacuum insulated core <NUM> may have a variety of shapes and configurations as may be required to fit spaces formed between inner and outer components in a particular application. Also, additional pieces of core material <NUM> may be utilized to provide additional thickness in one or more areas of core <NUM>. With reference to <FIG>, the core <NUM> may also be made by adding additional pieces of core material or alternatively by forming the core material into a 3D shape that substantially matches the internal shape of the door (less allowance for the adhesive <NUM>).

With reference to <FIG>, door <NUM> may include a 3D vacuum core 24A that is disposed between a wrapper 18A and liner 20A. The vacuum core 24A includes a generally planar central portion 68A and sidewalls <NUM>. The sidewalls <NUM> have increased thickness that may be formed utilizing additional pieces of core material <NUM> (<FIG>). During assembly, two-sided adhesive tape <NUM> or hot-melt adhesive is utilized to adhesively secure the vacuum core 24A to external wrapper <NUM>. Adhesive <NUM> is then utilized to secure liner 20A to vacuum core 24A. Wrapper <NUM> may include a flange <NUM> that overlaps a flange <NUM> of liner 20A. The flanges <NUM> and <NUM> may be attached/sealed utilizing adhesives and/or mechanical fasteners (not shown) or other suitable arrangement. Flanges <NUM> and <NUM> may also be held in place by adhesive <NUM> such that additional adhesives and/or mechanical fasteners are not required to separately interconnect flanges <NUM> and <NUM>. The liner 20A may include an inwardly-projecting portion <NUM> having an internal space <NUM> that may be filled with adhesive <NUM>.

The vacuum core 24A may be configured to fit closely against wrapper 18A, such that very thin two-sided adhesive tape <NUM>, hot melt adhesive, or other suitable adhesive may be utilized to secure the vacuum core 24A to the wrapper 18A. Due to variations in the dimensions of the wrapper 18A, liner 20A, and vacuum core 24A, a gap "G" is necessary between liner 20A and vacuum core 24A to account for the dimensional variations. In a preferred embodiment, the gap G is nominally about <NUM> to accommodate variations in the thickness of core 24A of about +/-<NUM>, and variations in the dimensions of wrapper 18A and/or liner 20A.

The adhesive <NUM> may comprise a two-part polyurethane adhesive having low viscosity prior to curing. As discussed above, the vacuum core 24A may be adhesively secured to external wrapper 18A utilizing two-sided adhesive tape or other thin layer of adhesive. The adhesive <NUM> can then be poured over vacuum core 24A in an "open pour" process. Liner 20A can then be positioned over the vacuum core 24A, and upper and lower tool components or fixtures <NUM> and <NUM> may be utilized to hold the wrapper 18A and liner 20A in position relative to one another while adhesive <NUM> cures. As wrapper 18A and liner 20A are pressed together, uncured liquid adhesive flows within and fills gap G. Peripheral flanges <NUM> and <NUM> of wrapper 18A and liner 20A may also be adhesively or mechanically interconnected utilizing suitable known processes. Alternatively, adhesive <NUM> may be used to bond flanges <NUM> and <NUM> together. After the adhesive <NUM> cures, the assembled door <NUM> may be removed from the tools <NUM> and <NUM>.

Alternatively, rather than an open pour process, after vacuum core 24A is adhesively secured to wrapper 18A, the liner 20A may be positioned over the vacuum core 24A and wrapper 18A prior to introduction of adhesive <NUM>. The adhesive <NUM> may then be injected into the gap "G" between vacuum core 24A and liner 20A, and tools or fixtures <NUM> and <NUM> may be utilized to retain the wrapper 18A and liner 20A in position relative to one another during curing of adhesive <NUM>. After the adhesive <NUM> cures, the assembled door <NUM> may be removed from the tools <NUM> and <NUM>.

The adhesive <NUM> preferably comprises a relatively low viscosity adhesive that is capable of flowing into the gap "G" (<FIG> and <FIG>) between the liner and the vacuum core panel prior to curing. The adhesive may comprise a two-part polyurethane. The adhesive <NUM> is preferably significantly lower viscosity than conventional polyurethane foam, and has superior adhesive properties. An example of a suitable adhesive <NUM> is a Balindur™ polyurethane foam/adhesive available from BASF of Ludwigschafen, Germany. Also, although a two sided adhesive tape <NUM> (<FIG>) or hot melt adhesive or other very thin adhesive is preferably used to adhesively bond the wrapper <NUM> to the core <NUM>, a thin layer of adhesive <NUM> may also be utilized to bond wrapper <NUM> to the vacuum core <NUM>.

With reference to <FIG>, door/drawer <NUM> may include an external wrapper 18B, liner 20B, and vacuum core 24B. The drawer <NUM> may be fabricated in substantially the same manner as the door <NUM> as described above in connection with <FIG>, except that drawer <NUM> includes an internal space <NUM> formed by an outer portion <NUM> of wrapper 18B. The internal space <NUM> may be filled with polyurethane foam <NUM>. The polyurethane foam <NUM> may comprise polyurethane foam of the type utilized to insulate conventional (i.e. non vacuum-insulated) refrigerator cabinets and the like. The wrapper 18B may be secured to core 24B by two-sided adhesive tape <NUM>, hot melt adhesive, or other suitable thin adhesive. The liner 20B is secured to the vacuum core 24B by adhesive <NUM> utilizing one of the processes discussed above in connection with <FIG>.

Claim 1:
A method of making a vacuum insulated refrigerator component (<NUM>, <NUM>, <NUM>, <NUM>), the method comprising:
forming a wrapper (<NUM>, 18A, 18B, 18C) having inner and outer opposite sides and a periphery;
forming a liner (<NUM>, 20A, 20B, 20C) having inner and outer opposite sides and a periphery;
providing a vacuum insulated core (<NUM>, 24A, 24B, 24C) comprising a filler material (<NUM>) disposed inside a substantially impermeable envelope (<NUM>), wherein the envelope (<NUM>) is evacuated to form a vacuum inside the envelope (<NUM>), and wherein the vacuum insulated core (<NUM>, 24A, 24B, 24C) comprises a 3D core having a first wall (<NUM>), and a second wall (66A, 66B, 66C, 66D) extending transversely relative to the first wall (<NUM>);
adhesively securing the vacuum insulated 3D core (<NUM>, 24A, 24B, 24C) to at least a selected one of the wrapper (<NUM>, 18A, 18B, 18C) and liner (<NUM>, 20A, 20B, 20C) by causing a low viscosity uncured two-component adhesive (<NUM>) to flow between the vacuum insulated 3D core (<NUM>, 24A, 24B, 24C) and the selected one of the wrapper (<NUM>, 18A, 18B, 18C) and the liner (<NUM>, 20A, 20B, 20C);
assembling the wrapper (<NUM>, 18A, 18B, 18C) and the liner (<NUM>, 20A, 20B, 20C) to form an interior space, wherein the vacuum insulated 3D core (<NUM>, 24A, 24B, 24C) is disposed in the interior space;
interconnecting the wrapper (<NUM>, 18A, 18B, 18C) and liner (<NUM>, 20A, 20B, 20C); and:
curing the adhesive (<NUM>),
wherein:
the uncured two-component low viscosity adhesive (<NUM>) is deposited utilizing an open pour process;
the wrapper (<NUM>, 18A, 18B, 18C) includes a central wall portion and edge walls that extend transversely from the central wall portion to form a core-receiving space;
the vacuum insulated 3D core (<NUM>, 24A, 24B, 24C) is positioned in the core-receiving space and a lower side of the vacuum insulated 3D core (<NUM>, 24A, 24B, 24C) is adhered to the wrapper (<NUM>, 18A, 18B, 18C) utilizing double-sided adhesive tape or hot melt adhesive;
depositing the uncured two-component low viscosity adhesive (<NUM>) onto an upper side of the vacuum insulated 3D core (<NUM>, 24A, 24B, 24C).