The present invention relates to a cooling device, the structural alignment of which is improved.
In cooling devices, especially in refrigerators and freezers, an insulating material, that is generally closed-cell rigid polyurethane, is filled between the liner and the outer case of the body in order to provide heat insulation between the inner volume and the outer environment. One or more of the walls of the outer case, and preferably usually the back outer wall, can be made of a semi-rigid papery material, such as a cardboard, which provides light weight together with optimal insulation and acoustical properties.
In the state of the art, the international patent application n.
Generally, during the production process, the liner and the outer case of the body are placed in a mold and the insulating material, such as polyurethane, is injected as a liquid between them while in the mold, and over a short period of time expands to fill the space between liner and outer case. Due to the injection technic used to fill the intermediate volume between the liner and the outer case of the body, the liquid insulating material is not homogeneously distributed in such volume. The body is usually demolded before the complete curing and cooling of the insulating material has occurred, so that the latter continues cooling after the body has been demolded. Due to the initial inhomogeneous distribution of the insulating material in the intermediate volume, differential pressure forces act on the liner and on the outer case of the body and irregular contracting of the foamed mass or local collapsing of the cellular structure of the foam can occur which can lead to deformation in particular of the walls of the outer case made of papery material.
This entails problems in the structure of the body and more specifically a poor structural alignment of the body due to the deformation of the walls of the outer case made of papery material, which causes misalignments on the body, on the accessories mounted on the body and on the door subsequently mounted on the body. These misalignments may provoke an early wearing of the accessories mounted on the body, such as for instance hinges, and are particularly problematic for double door or multi door refrigerators, wherein a perfect matching of the doors defining the front wall of the refrigerator is required.
Such misalignments and the consequences deriving from them adversely affect the overall satisfaction on the final user.
The aim of the present invention is the realization of a cooling device comprising a body which structural alignment is increased.
The cooling device realized in order to attain the aim of the present invention is defined in the first claim and the respective claims thereof.
In an embodiment the protrusions/recesses are obtained by pressing the papery material board, in an easy and quick manner.
The protrusions/recesses are arranged substantially on the whole surface of the back wall, so as to increase the mechanical resistance of the whole back wall.
The protrusions/recesses extend along both vertical and horizontal parallel directions defining concentric closed shapes spaced apart from one another on the outer surface of the back wall.
In an embodiment, the back wall comprises a raised central plateau wherein the thickness of the back wall is advantageously increased and which can be obtained by means of blow molding.
In a version of this embodiment the thickness increase of the back wall on the central plateau is comprised between 5 mm and 25 mm and preferably it is comprised between 10 mm and 20 mm. In a further version of this embodiment, the protrusions/recesses have a thickness and/or a depth which is substantially equivalent to half the thickness of the central plateau.
According to an embodiment, the cooling device of the invention is a refrigerator and in particular it is a double door refrigerator, while according to a further embodiment it is a multi-door refrigerator.
The cooling device realized in order to attain the aim of the present invention is illustrated in the attached figures, where:
The elements illustrated in the figures are numbered as follows:
The cooling device 1 comprises a body 2 that has a liner 3 and an outer case 4 comprising a back wall 5 made of a semi-rigid papery material such as a paperboard or a cardboard.
The liner 3 and the outer case 4 define between them an intermediate volume 6 filled with an insulation material 7, such as for instance polyurethane foam.
According to the present invention, the back wall 5 of the outer case 4 has an outer surface 8 and it comprises a plurality of protrusions 9 and/or recesses 10 arranged on the outer surface 8. The protrusions 9 and/or the recesses 10 increase the stiffness of the back wall 5, which therefore does not deform due to the transformations of the insulation material placed in the intermediate volume 6 during the production process of the body 2 of the cooling device 1. This ensures a better structural alignment of the body 2, so that no additional working phases, like a re-alignment phase, are required during the production of the body 2, thus diminishing the production time and cost.
In the attached figures and in the following a cooling device 1 having only the back wall 5 of the outer case 4 made of a papery material is described. However, the outer case 4 may comprise also further walls, such as for instance the lateral walls, made of a papery material and provided with protrusions 9 and/or recesses 10 according to the present invention, without departing from the scope of protection of the present invention.
Preferably both protrusions 9 and recesses 10 are provided on the outer surface 8 of the back wall 5.
The protrusions 9 and/or recesses 10 provided on the back wall 5 contribute also to improve the acoustical properties of the body 2 of the cooling device 1, diminishing the vibrations and hence the noise produced by the cooling device 1.
According to an embodiment, the protrusions 9 and/or recesses 10 are obtained on the outer surface 8 of the back wall 5 by pressing. This allows to easily obtain a back wall 5 with variable thickness, thus defining the desired protrusions 9 and/or recesses 10 on its outer surface 8.
The protrusions 9 and/or the recesses 10 are arranged substantially on the whole outer surface 8 of the back wall 5.
The protrusions 9 and/or recesses 10 define a plurality concentric closed shapes, spaced apart from one another.
The above mentioned arrangements of the protrusions 9 and/or recesses 10 on the outer surface 8 of the back wall 5 ensure a substantially even stiffness of the back wall 5 along its whole vertical and horizontal extension, thus avoiding the presence of weak areas on the back wall 5 which could collapse and deform during the production process of the cooling device 1.
According to an embodiment illustrated in the attached figures, the back wall 5 comprises a raised central plateau 11 and the protrusions 9 and/or recesses 10 are provided on the outer surface 8 of the back wall 5 on the raised central plateau 11.
In particular, the thickness of the back wall 5 is increased on the central plateau 11. In a version of this embodiment, the thickness increase of the back wall 5 on the central plateau 11 is comprised between 5 mm and 25 mm, and preferably is comprised between 10 mm and 20 mm. The presence of the central plateau 11 having in particular an increased thickness contributes to improve the stiffness of the back wall 5.
In an embodiment, the protrusions 9 and/or recesses 10 have a thickness and/or a depth substantially equivalent to half of the thickness of the central plateau 11. This ensures that optimal mechanical characteristics are conferred to every part of the back wall 5, without having portions of the back wall 5 having too little thickness that could result in a weakening of the back wall 5 while at the same time not increasing excessively the amount of space occupied by the body 2.
According to an embodiment, the raised central plateau 11 is obtained on the outer surface 8 of the back wall 5 by means of blow molding.
In an embodiment, the cooling device 1 above described is a refrigerator. In particular, the cooling device 1 above described is a double door refrigerator and in a further embodiment it is a multi-door refrigerator. As previously specified, in fact, having a back wall 5 with mechanical characteristics that avoid possible deformations of the back wall 5 itself and, consequently, of the body 2 is particularly important in case of double or multi door refrigerators where misalignments on the body 2 would result immediately apparent due to a poor matching of the doors on the front of the refrigerators, thus diminishing the user satisfaction and possibly affecting the overall cooling performances of the refrigerator.
By means of the present invention, adequate stiffness is provided to the back wall 5 of the body 2 of the cooling device 1 and, more in general, to the walls of the outer case 4 made of a papery material, thus avoiding possible deformations of such walls during the production process of the cooling device 1 and hence misalignments on the body 2 that could lead to an early wear of the accessories of the cooling device 1, to poor aesthetical appearance of the cooling device and, more in general, to a poor overall satisfaction of the user.
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