US3335538A - Refrigerator doors - Google Patents

Description

2 Sheets-Sheet 1 Filed May 5, 1965 //V V54 79/? J. 1/ Ganzl'ndffi ATTORNEYS 15, 1967 .1. v. GANZINOTTI 3,335,538

REFRIGERATOR DOORS Filed May 5, 1965 2 Sheets-Sheet 2 Mow/ ATTORNEYS United States Patent 3,335,538 REFRIGERATOR DOORS Jean Victor Ganzinotti, Brive, France, assignor to Etablissements Maille et Vagneux and Equipement Moderne Industrial par Application du Caoutchouc Manufacture et des Plastiques E.M.I., both of Paris, France, both bodies corporate of France Filed May 5, 1965, Ser. No. 453,255 Claims priority, application France, May 6, 1964, 973,539 3 Claims. (Cl. 52-624) The present invention relates to refrigerator doors.

Refrigerator doors must be thermally insulating and must have a mechanical strength and a rigidity sufficient to accommodate, without damage, the considerable strain which is applied thereto in order to obtain a good seal between the door and the refrigerator.

However, thermally insulating materials generally have relatively weak mechanical properties.

Moreover, when the door is closed, the external and internal surfaces of the door are at different temperatures, for example, the internal surface may be 30 C. and the external surface may be C., stresses are set up which tend to distort the door.

Finally, all the parts of the internal surface of the door are not at the same temperature, the part of this surface located within the frame defined by the sealing joint is at the temperature of the interior of the refrigerator, for example, 30 C., whilst the part located outside this frame is at the temperature of the external atmosphere, for example, +20 C. There results from this difference in temperature, constraints or stresses which sometimes almost cause bursting. Up to the present time, refrigerator doors have been generally constituted by a frame made of a mechanically resistant material .filled with a thermally insulating substance rigidly fixed to the frame, for example by adhering, and by coverings which are also fixed to the frame and to the thermally insulating substance. Thus, it is endeavoured to produce doors, all the elements of which are closely fixed to one another with the object of giving the assembly maximum mechanical resistance and maximum rigidity.

In order that these doors may resist thermal stresses or constraints, the different elements are given dimensions which are much greater than those which they would have had if they had to fulfill the only function for which they have been intended. Thus, the thickness of the thermal insulating substance is greater than that necessary to ensure only thermal insulation, the dimensions of the frame are greater than are necessary to resist the single mechanical strain while the door is being closed, and the coverings have larger dimensions and superior quality than is necessary to protect the thermal insulating substance. These doors are expensive and heavy, which renders their manual manipulation difilcult and complicates the problem of their automatisation.

Moreover, almost all these doors possess defects when in use; in particular, they tend to distort and their seal becomes defective.

The present invention has for an object to provide a refrigerator door which is simpler and cheaper to construct and the construction of which is easier than existing refrigerator doors.

It also has for an object to provide a lighter door which, when in use, does not possess the disadvantages of existing doors. According to the invention, the door comprises a frame made of a rigid and mechanically re sistant material, a panel made of a thermally insulating substance incorporated in the frame without being rigidly secured thereto, and a joint element capable of forming a seal between the door and the cold chamber of a refrigerator, which element possesses an appendix which serves to secure the joint element and ensures, at the same time, the assembly of the frame and panel in a supple and flexible manner.

In order that the invention may be more clearly understood, various embodiments thereof will now be described with reference to the accompanying drawings, in which:

FIGURE 1 is a diagrammatic plan view of the upper left hand part of a refrigerator door constructed in accordance with one embodiment of the invention,

FIGURE 2 is a section along the line 22 of FIG- URE 1,

FIGURE 3 is a section, similar to that of FIGURE 2, of a second embodiment,

FIGURE 4 is a section, similar to that of FIGURE 2, of a third embodiment.

Referring to FIGURES 1 and 2, the refrigerator door comprises a panel 1 made of a thermally insulating substance located in a mechanically resistant frame 2, and a sealing joint element 4 which ensures that a good seal is formed between the door and a cold chamber 5 when the door is closed. The element 4 is provided along its whole length with a fixing appendix 4a located in a groove defined between the frame 2 and the panel 1.

The panel 1 is made of any rigid suitable thermally insulating substance, such as cork or a cellular synthetic substance such as polystyrene, polyurethane or polyvinyl chloride. It is possible to form the panel from a plurality of layers. Since, in the door according to the invention, the panel fulfils only the single function of thermal insulation, if the cellular substance which constitutes it has closed cells, a cover need not be provided, or a light cover may suffice, disposed on the external part of the door, the cover being, preferably, separated from the panel. The cover may be, for example, a metal sheet fixed directly on to the frame and separated from the :panel.

The frame 2 which is intended to accommodate the single mechanical load exerted whilst the door is being closed, is made of a substance having good mechanical properties. It may, for example, be made of metal, and in this case, it may be advantageous to use a relatively light metal such as an aluminum-based alloy, a plastics material, or a Stratified substance made of glass fibre and polyester resin. In this embodiment, the frame is produced by assembling profiled elements having the outline shown in FIGURES 1 and 2.

The frame 2 has a projecting 2a which engages in a groove in the panel 1 so as to define therewith a groove 3 which, in the embodiment shown in FIGURE 1, has a trapezoidal cross-section, but which may equally have any other shape, for example, polygonal, provided that the width of the opening of the groove is less than the largest transverse dimension of the groove, i.e. provided that the groove is undercut.

It will be noted that the fframe 2 and the panel 1, the dimensions of the latter being slightly smaller than those of the former are not fixed to one another, either by gluing or in any other way, so that they are completely independent of one another.

The assembly of the frame 2 and panel 1 is effected by means of the appendix 4a of the sealing joint element 4 which is made of rubber or any other similar flexible or resilient material. The appendix 4a, which has a generally expandable or inflatable configuration, is placed, after compression, into the groove 3 thereby ensuring at the same time that the panel 1 is properly keyed in the frame 2, that the joint element is secured to the door, and that the seal is provided between the frame 2 and the panel.

In the previous embodiment, a joint element which is hollow and inflatable has been shown, but it will be understood that the invention is not limited to the use of this type of joint element and that it is applied in the same way whatever may be the type of joint used, provided that it has an appendix having a generally resilient or inflated configuration.

In order to assemble the door, the joint element may be, for example, arranged around the panel whereafter the various components of the frame which are assembled may be put in position as the appendix 4a for fixing the joint element is compressed.

Since the frame and panel are no longer integral, the stresses or constraints resulting from the differences in thermal expansion or contraction therebetween, differences due to the differences in the coeflicients of thermal expansion and also to the difference in temperatures to which they are subjected, are eliminated. Since the appendix 4a is made of a flexible or resilient substance, compressed in the assembly, compensation of the dimensional variations is accommodated. Similarly, the tendency of the panel to be distorted due to temperature differences between its internal and external parts is greatly diminished if not eliminated.

In the embodiment shown in FIGURE 3, the appendix 4a of the joint is expanded or inflated by means of a fluid which may be a liquid or gas, and the part consituating the frame is provided with projections or clips 21) which are embedded in or penetrate the substance of the panel. During assembly, these clips 2b prevent any movement of the panel with respect to the frame and thus facilitate the production of the assembly.

FIGURE 3 also shows a screw 6 which may, for example, serve to assemble the door lock or catch of the door when closed. In this embodiment, all the elements of the structure are positively fixed together after the appendix 441 has expanded, which appendix acts in the same way as that shown in FIGURE 2.

In the embodiment shown in FIGURE 4, an expandable element 7, separate from the joint element 4, carries out the different functions of the appendix 4a in the previous embodiment. It will be noted that in this embodiment, the joint element 4 still includes an appendix 40, but this appendix only serves to enable the joint element to be fixed or held between the fframe 2 and the expandable element 7.

It will also be noted that, in this embodiment, the groove defined between the frame and panel is not trapezoidal, but has, in part, a rounded shape corresponding to the shape of the element 7.

The expandable or inflated element 7, which is in the form of a cylinder, is made of a supple substance which 4 is impermeable to air and possibly reinforced by a tissue. It is inflated with air to a pressure of the order of 1.3 to 1.5 kg./cm.

It will be seen that, in the refrigerator doors according to the invention, the thermal insulating substance may be of minimum thickness compatible with good insulating properties, and that the frame has to resist only the strains which are exerted during closing of the door.

Moreover, the frame, by virtue of its construction, is disposed completely outside the zone where the thermal changes are produced. It may, therefore, be made from any material selected solely for its mechanical characteristics.

Finally, the doors according to the invention may be easily manufactured, since the panel does not need a particular preparation and since the frame or its components may be prepared independently of the panel.

I claim:

1. A refrigerator door comprising a panel of a thermally insulating substance, a frame of a substance having high mechanical resistance surrounding said panel, the frame and the panel defining a groove, said groove having a constricted opening, and a sealing element having a main body and along its entire length a fixing appendix made of a flexible substance, an expandable element located within the groove adjacent said appendix to urge the appendix against a wall of the groove in a compressed state so as to maintain the assembly of frame and panel in a resilient manner, said main body of the sealing elernent being compressible on closing the refrigerator door, to form a seal for the door.

2. A refrigerator door according to claim 1, wherein said expandable element and part of said groove have a rounded cross-sectional shape.

3. A refrigerator door according to claim 2, wherein said expandable element is cylindrical, impermeable to air and inflated to a pressure of the order of 1.3 to 1.5 kg./cm.

References Cited UNITED STATES PATENTS 2,036,781 4/ 1936 Steenstrup 49489 2,278,3 31 3/ 1942 Meyercord 52-624 2,751,638 6/ 1956 Wallenbrock 49486 3,040,393 3/ 1962 Dailey 49-489 3,243,855 4/1966 Houvener 52--573 DAVID J. WILLIAMOWSKY, Primary Examiner.

KENNETH DOWNEY, HARRISON R. MOSELEY, Examiners.

Claims (1)

1. A REFRIGERATOR DOOR COMPRISING A PANEL OF A THERMALLY INSULATING SUBSTANCE, A FRAME OF A SUBSTANCE HAVING HIGH MECHANICAL RESISTANCE SURROUNDING SAID PANEL, THE FRAME AND THE PANEL DEFINING A GROOVE, SAID GROOVE HAVING A CONSTRICTED OPENING, AND A SEALING ELEMENT HAVING A MAIN BODY AND ALONG ITS ENTIRE LENGTH A FIXING APPENDIX MADE OF A FLEXIBLE SUBSTANCE, AN EXPANDABLE ELEMENT LOCATED WITHIN THE GROOVE ADJACENT SAID APPENDIX TO URGE THE APPENDIX AGAINST A WALL OF THE GROOVE IN A COMPRESSED STATE SO AS TO MAINTAIN THE ASSEMBLY OF FRAME AND PANEL IN A RESILIENT MANNER, SAID MAIN BODY OF THE SEALING ELEMENT BEING COMPRESSIBLE ON CLOSING THE REFRIGERATOR DOOR, TO FORM A SEAL FOR THE DOOR.

Images