GASKET FOR REFRIGERATORS WITH A PROFILED OUTER DOOR

Abstract: This invention refers to a gasket (1) made of a plastic material for refrigerators chests and the like, equipped with an inner door (30) and an outer door (31), rigidly connected to each other by a foamed material injected in the hollow space provided between them for insulating purposes, of a type in which said outer door (31) is profiled along one or more sides with a groove (10) in the area next to its extremity overlaying said inner door, where said groove (10) functions as a seat to receive an appropriate fastener (11) for said gasket and the latter is fitted with a bellows-type section (20) made of a soft plastic material capable of providing a closing seal between the door and the chest (32), and a base (12) from which said fastener (11) extends to the outer door.

Description: "GASKET FOR REFRIGERATORS WITH A PROFILED OUTER DOOR" In the industrial branch of refrigerator profiles equipped with a magnetic sealing gasket, sealing systems of a type such as described in the U.S. patent 4.167.759 and in the European patent 319.087 by the same Applicant are known. These systems have the common characteristic of assembling, manually or in an automated manner, a rigid profile fitted with a soft gasket co-extruded with the same, an inner door shell on one side and an outer door on the other, and of producing, after the assembly, a foamed material in the hollow space formed between the inner and outer door in order to achieve the thermal insulation of the same. One of the drawbacks arising in such sealing systems is that in order to produce the foaming material inside an appropriate mold the soft part of the gasket is subjected to a squashing action, which may, in the event of an anomalous positioning inside the foaming mold, even produce a permanent deformation of the mentioned gasket. On the other hand, different sealing systems have recently been developed, where the need of having a rigid profile of a rather complex geometric shape to allow supporting the soft sealing element on one side and to achieve the coupling of the inner and outer door as well as to fit an alternative gasket on the opposite side has been eliminated. This has become possible by configuring the same outer door with a groove, generally arranged along the perimeter and capable of functioning as a seat to receive a soft gasket. The system radically differs from the one discussed above in reference to the patents by the same Applicant, due to the fact that it j.s in this case possible to arrange for an inner/outer door assembly by executing the thermally insulating foaming step inside the hollow space formed between them prior to installing the gasket. In other words, this system first produces a complete door, meaning a fully assembled and foamed-out door leading to the additional effect of holding the inner and outer doors permanently coupled to each other, and subsequently provides for mounting the soft gasket by a fastener element, for instance an anchor or leg capable of penetrating and latching by interference into the perimeter hollow with which the outer door has been molded. A gasket installed according to a technology of this kind is shown in Figure 1 of the drawings attached to this description. With reference to this Figure 1, a gasket of the known art is indicated by G and operatively assumes the configuration shown by a full line. In this operating condition, the gasket G is installed across an anchoring leg E inside a groove 10 provided along the perimeter of an outer door 31. The latter is assembled with the plate of an inner door 30, where the inner door 30 and the outer door 31 are held together by a thermally insulating foamed material used to fill the hollow space formed between them. This gasket is produced from a single type of soft plastic material and fitted at its upper end with a seat for a magnetic material M. As can be seen, in the lower part a fastening element E projects from a base D produced with a thickness greater than that of the remainder of the gasket, so as to attain an adequate stability against the stresses induced by the door's opening and closing motions, and therefore by the traction of the magnet on the part of the refrigerator chest. These stresses basically result into two forces, as shown in Figure 1 by the vectors A and B which are basically acting vertically to each other. The effect of a continuous application of such forces A and B on the gasket G is to generate some deformations, as shown in a simplified manner by a dashed line in Figure 1. As can be seen, these deformations are substantially due to a lifting action of the base D in the outer lateral area of the system, accompanied by a corresponding lifting action of the sealing strip C, which should in an operating position fit against the inner door (30) so as to achieve a lateral seal. The deformation caused by the gasket's stretching under the effect of the magnetic traction is considerable. In order to attempt reducing this deformation, the only possible solution is to try to increase the thickness of the base D, which adversely affects the production costs. Moreover, such a solution is incapable of preventing the deformations generated in this manner. The magnetic attraction also results in a constant lifting action of the anchoring leg E inside the outer door's groove 10. This entails the need to size this fastening leg E with a considerable thickness, which again affects the costs and at any rate fails to prevent the constant shifting action of the leg inside the groove 10, and consequently even runs the risk that such an anchoring leg may sooner or later jump off its seat. These problems are solved by a gasket according to this invention, which consists of a gasket 1 made of a plastic material for refrigerator chests and the like, equipped with an inner door 30 and an outer door (31) rigidly connected to each other by injecting a foamed material into the hollow space formed between them for thermal insulating purposes, of a kind in which said outer door 31 is profiled along one or more sides with a groove 10 in the area next to its extremity 13 overlaying said inner door 30, where said groove 10 functions as a seat to receive an appropriate fastener 11 of said gasket, where the latter presents a bellows- type portion (20) made of a soft plastic material capable of producing a sealing gasket between the door and the refrigerator chest 32, and a base 12 from which said fastener 11 extends to the outer door, characterized in that said gasket base 12 is made of a rigid plastic material produced by co-extrusion with the said soft plastic material of the bellows-type portion 20, and presents a substantially horizontal, flat or slightly curved configuration in the portion 14 in which said base overlays the extremity 13 of said outer door, while presenting a substantially oblique or vertical, flat or slightly curved configuration in the portion of the extremity 15, where said portion 15 of said base is externally overlaid, on the same side as the inner door 30, by a layer 16 of soft material co- extruded with the rigid material of said base, from which a sealing element 17 is extended so as to operatively rest against said inner door 30, while the mentioned soft layer 16 belongs to the lateral wall of said bellows-type portion 20. In order to provide a better understanding of the characteristics and advantages of the invention as substantially described above, a number of examples of a practical execution are given below, with reference to the Figures from 2 to 8 of the attached drawings. With reference to the mentioned drawings, Figure 2 shows a gasket according to the invention operatively mounted on a door of the refrigerator, in a cross- sectional view. Figures 3, 4, 5, and 6 show nominal sections of gaskets according to the invention, based on an equal number of variants. Figures 7 and 8 show further variants of the gaskets according to the invention, again operatively mounted on the refrigerator and in cross-sectional views. With reference to Figure 2 of the attached drawings, a gasket 1 according to the invention is mounted on one door of the refrigerator and/or freezer in which the plate of an inner door 30 and an outer door 31 are rigidly connected to each other by the foam 8 of a thermally insulating material injected into the hollow space formed between them. For this purpose the outer door 31 is profiled along one or more sides, for instance preferably along its entire perimeter, with a groove 10 profiled in the area next to its extremity 13 which overlays the mentioned plate of the inner door 30. The groove 10 functions as a seat to receive the mentioned gasket. The gasket 1 is made of a co-extruded plastic material. It is in fact constituted of a bellows-type portion 20 made of a soft plastic material, so as to achieve a closing seal between the door and the refrigerator chest 32. For this purpose the gasket ends in its upper part with a seat 19 to hold the magnetic insert. In its lower part the gasket 1 presents a base 12 from which a fastener 11 extends to the outer door. The gasket base 12 is made of a rigid plastic material shaped by co-extrusion with the mentioned soft plastic material of the bellows-type portion 20, and presents a substantially horizontal configuration in its central portion, which in the case of Figure 1 turns out to have slightly a curved profile in the direction of the outer door 31. This central portion of the base in which the same overlays the extremity 13 of the outer door is indicated by the reference number 14 in the gasket of Figure 2. The terminal outer part of the same base is separated from this portion 14 of the base 12. In the example of Figure 2, this terminal part presents an oblique configuration turned in the direction of the bellows-type portion 20 of the gasket. This outer wall of the bellows-type area and this portion of the extremity 15 of the base 12 are in fact co-extruded, and the co-extruded area of the example shown in Figure 2 extends even over a short stretch of the portion 14 of the base 12, so that in the contact area between the latter and the extremity 13 of the outer door 31 the gasket rests against the same outer door along a stretch of soft gasket 21. The layer 16 of soft material co-extruded with the rigid material of said external base, on the same side as that of the inner door 30, projects with a lip 17 having a sealing action and rests against the mentioned inner door 30, as seen in Figure 2. The opposite side of the base in the co-extruded area, between the bellows-type portion 20 and the base 12, also provides for an extension of the soft material along the sealing lip 18 which rests against the outer door 31. In its lower part the base 12 of the gasket 1 is equipped with a fastener 11 capable of coupling to the seat 10 provided in the outer door 31. In the case of Figure 2, this fastener 11 is for instance constituted of a rigid leg 7 capable of entering the groove 10 and latching-up inside the same by interfering elements constituted of a flexible flap 22 or a rigid material capable of flexing in the presence of a soft co-extruded elbow 23, designed to form a seal on the outer door thanks to some soft sealing strips 24 and 25 capable of deforming by interference and of functioning as a seal against the edge of the outer door 31. The Figures 3, 4 and 5 of the attached drawings illustrate variants of the gasket shown in Figure 2, both as refers to the configuration of the soft bellows-type portion 20 as to the fastener 11. It can in particular be seen that the fastener in Figure 4 is constituted of a rigid anchor, whose lower part is fitted with two flexible flaps 26 ending in a sealing strip 27. The center of the same anchor is also fitted with two soft sealing strips 28 which lock into the groove 10 of the outer door, again by deformation and interference. The variants shown in Figures 3, 4 and 5 also show that the base 12 can in its portion 14 also have a slightly curved configuration to different extents, just as the co-extruded areas between the mentioned base 12 and its terminal portion 15 may also have different configurations . Still another different configuration of the fastening leg 11 is shown in Figure 5, in which it continues to be a substantially rigid element 29 carrying soft sealing strips 32. Further variants of the gasket according to the invention are shown in the Figures 6 to 8, which show in particular that the fastening element 11 is entirely constituted of a soft material, just like the leg 33 of Figures 6 and 8, or the soft-rigid co-extrusion 34-35 shown in Figure 7. In particular, the Figures 7 and 8 also show a different configuration of the outer door according to a more complex geometry, which at any rate provides a groove 10 capable of receiving the fastening element 11 of the gasket according to the invention. In particular, the variant of Figure 6 shows that the sealing element 17 destined to operatively rest against the plate of the inner door 30 is not a lip as in the foregoing figures, but a tubular element particularly suitable for those executions of the door plate which extend toward the chest in a shoulder-like configuration. Regardless of the various forms of execution described above, the gasket according to this invention is capable of effectively solving the technical problem described in the beginning, as it provides for a rigid base 12 along a substantially horizontal central portion of a flat or slightly curved shape as shown in the examples of the figures, which projects a substantially oblique or vertical external portion of a flat or slightly curved shape capable of avoiding the typical deformations shown for example in Figure 1 with respect to the known art, meaning deformations caused by the lifting stresses of the base or of its external extremity, as well as a lateral instability of the gasket, thanks to the fact that it provides a practically undeformable corresponding portion in the gasket. This solution of the technical problem is above all accompanied by the further advantage of being able to provide thin layers in the rigid part of the gasket, thus facilitating even an automatic installation of the gasket and minimizing production costs. This advantage is even more evident where it is desired to use a rigid recycled or regenerated material, which is entirely feasible because the rigid material is practically hidden from sight once the gasket is operatively mounted on the refrigerator, so that any color divergencies go undetected. According to the invention, the fact of providing for a rigid base 12 extending on one side over an inclined or vertical plane 15 and on the other side over a the vertical fastener 11 with respect to the substantially horizontal plane of the base 12 generates a dimensional stability of the gasket and a rigidity which opposes the sagging typical of the soft gaskets made by the known art shown in Figure 1. This rigidity of the gasket according to the invention allows to handle the gasket itself by mechanical means, thereby making it possible to automate a few phases of its production as well as its application and installation on the door of a refrigerator. The rigid base 12 and its extensions 11 and 15 also allow producing a few notches or other reference systems useful for reducing the longitudinal dimensional tolerances of the gasket, which are typically in the range of 4-6 mm for the soft gasket of Figure 1. This reduction of the dimensional tolerances according to the invention may reach 1-2 mm, which represents a considerable advantage. According to the invention, the fastening element 11 is further capable of latching itself into the seat 10 of the outer door in a stable manner, better than a gasket solely made of a soft material based on the known art.

Claims: CLAIMS 1. A gasket (1) made of a soft material for refrigerator chests and the like, equipped with an inner door (30) and an outer door (31) rigidly connected to each other by injecting a foamed material into the hollow space formed between them for thermal insulating purposes, of a type in which said outer door (31) is configured along one or more of its sides with a groove (10) in the area next to its extremity (13) overlaying said inner door (30), where said groove (10) functions as a seat to receive an appropriate fastener (11) of said gasket, where the latter presents a bellows-type portion (20) made of a soft plastic material capable of producing a tight seal between the door and the chest (32) and a base (12) from which said fastener (11) extends up to the outer door, characterized in that said base (12) of the gasket is made of a rigid plastic material shaped by co-extrusion with the mentioned soft plastic material of the bellows-type portion (20) , and presents a substantially horizontal flat or slightly curved configuration in the portion (14) in which said base overlays the extremity (13) of said outer door, while presenting a substantially oblique or vertical, flat or slightly curved configuration in the portion of the extremity (15) where the said portion (15) of said base is externally overlaid, on the same side of the inner door (30), by a layer (16) made of a soft material co- extruded with the rigid material of the mentioned base, from which a sealing element (17) projects to operatively rest against said inner door (30) , while the mentioned soft layer (16) belongs to the lateral wall of said bellows-type portion (20) . 2. A gasket according to claim 1, characterized in that said sealing element (17) is a lip. 3. A gasket according to claim 1, characterized in that said sealing element (17) is a tubular profile. 4. A gasket according to claim 1, characterized in that said layer (16) of soft co-extruded material also extends to said portion (14) of said base overlaying the extremity (13) of said outer door (31) along at least that stretch (21) of said portion (14) which is operatively in contact with said extremity (13) . 5. A gasket according to claim 1, characterized in that said portion of the extremity (15) of said base (12) is oblique, and that consequently even the corresponding lateral wall of the bellows-type portion (20) is of the same type. 6. A gasket according to claim 1, characterized in that said portion of the extremity (15) of said base (12) is vertical, and that consequently even the corresponding lateral wall of the bellows-type portion (20) is of the same type. 7. A gasket according to claim 1, characterized in that said fastening element (12) is made of a soft material co-extruded with said base (12) . 8. A gasket according to claim 1, characterized in that said fastening element (11) is made of a rigid material. 9. A gasket according to claim 1, characterized in that said fastener (11) is made of a soft and rigid material.

Inventors: CITTADINI PAOLO, FERRANTE PIER PAOLO, CITTADINI, PAOLO, FERRANTE, PIER, PAOLO
Applicants: ILPEA IND SPA, INDUSTRIE ILPEA S.P.A.
Application year: 1999
Main classification: F25D23
IPC codes: F25D23