FR2835303A1 - Production of seal with fragile section comprises extruding complete seal, so that fragile section is connected to remainder by strips of material, one of which is ruptured before finishing - Google Patents

Abstract

The production of a seal (1) with a fragile section (A) comprises extruding the complete seal, so that the fragile section is connected to the remainder (B) of the seal by strips of material (20, 22). One of these is ruptured before finishing is carried out on the remainder of the seal, avoiding deterioration of the fragile section. An Independent claim is included for a seal as described above.

Description

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SEAL FOR FIXED OR MOBILE PANEL, AND METHOD
FOR MANUFACTURING THE JOINT.

 The invention relates to a seal for a fixed or movable panel, as well as a method of manufacturing said seal, knowing that the technical fields of application of the invention are very numerous.

 In a constant effort to improve the aesthetics of the seals, appearance coatings are used such as fabrics, flocks, paints, colored skins made of rubber or of a thermoplastic material, colored adhesives. ...

 In general, these seals are manufactured by extrusion and, for essentially economic reasons, the appearance coatings are deposited in line during the extrusion operation on a part of the seal, in particular on at least a lip which is called a cosmetic lip.

 However, in certain applications, the seal can be subjected to additional operations after its extrusion. These operations, called finishing operations, can in particular consist of an angle molding, an edge-to-edge welding molding, a thermoforming to give a permanent curvature to the seal, ...

The tools used for these finishing operations generate on the joint mechanical stresses resulting from the maintenance of the joint by contact in a mold, and / or thermal stresses resulting from the heating of a mold to a temperature which can reach 200 C. where the appearance coatings do not withstand such mechanical and thermal stresses, this results in local degradation of these coatings during these finishing operations.

 Faced with this problem, certain solutions are used, among which we can notably cite those consisting of:

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 - carry out a renovation of the appearance coating in its deteriorated part, but such an operation is costly and does not make it possible to restore its initial appearance, - adapt the tools used during the finishing operations to limit as much as possible the deterioration but without completely eliminating them, or - manufacturing the cosmetic lip and the seal separately, the lip being attached to the seal after the operation of finishing the seal, such a solution, although satisfactory, is however very expensive.

 All these solutions therefore have their limits and they do not allow a satisfactory quality / price ratio to be obtained.

 An object of the invention is to provide a new solution to this problem of local deterioration of a fragile part of a joint during a joint finishing operation, knowing that the fragile part does not only concern a coating. appearance but any coating likely to be damaged locally during a joint finishing operation.

 To this end, the invention provides a method of manufacturing a seal for a fixed or movable panel, the method being of the type consisting in manufacturing a seal comprising a fragile part, such by extruding a coating of appearance or functional, over at least part of its length, and then performing at least one joint finishing operation, process which is characterized in that it consists, before carrying out said finishing operation, of separating at least locally the fragile part of the joint to release it from the remaining part of the joint, to carry out the finishing operation on the remaining part of the joint to avoid damaging the fragile part, and to re-join the fragile part to the remaining part of the joint after the finishing operation.

 In general, the method consists in providing at least one bridge of material to connect the fragile part and the remaining part of the joint.

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 According to one example, the manufacturing process consists in providing at least two bridges of material between the fragile part and the remaining part of the seal during the extrusion operation, and in breaking at least one of the two bridges of material before performing the finishing operation on the remaining part of the joint.

 According to a first operating mode, the process may consist, before the joint finishing operation, of breaking one of the two material bridges and using the other material bridge as a hinge to pivot the fragile part relative to the remaining part of the seal and move it away from it.

 According to a second operating mode, the process can consist, before the finishing operation, of breaking the two bridges of material to distance the fragile part from the remaining part of the joint.

 The invention also relates to a seal comprising at least one fragile part, and which is characterized in that it comprises means for at least locally separating the fragile part from the remaining part of the seal, and being able to perform an operation on the seal without damaging its fragile part.

 In general, the so-called fragile part of the joint is that which includes the appearance coating, knowing that this fragile part can be a lip or a tubing for example.

 An important advantage of the invention is to be able to arrive at a solution which is of a very satisfactory quality / price ratio with regard to the previous solutions mentioned above.

 Other advantages, characteristics and details of the invention will emerge from the additional description which follows with reference to the accompanying drawings, given solely by way of example and in which: - Figure 1 is a sectional view of a seal, known per se, which is used in particular as a door seal in industry

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 automotive and which in particular comprises a fragile part such as a cosmetic lip with an appearance coating; - Figures 2 and 3 are schematic sectional views of a tool such as a mold for performing a finishing operation on the door seal illustrated in Figure 1; - Figure 4 is a sectional view of the door seal illustrated in Figure 1 but which comprises means according to the invention to be able to protect the fragile part of the seal during a finishing operation of said seal; - Figures 5 and 6 illustrate a first procedure for using the means of Figure 4 to move the fragile part of the seal away from the aggressive parts of a mold during a joint finishing operation; and - Figures 7 to 9 illustrate a second procedure for using the means of Figure 4 so that the fragile part of the seal is located outside of a mold during a joint finishing operation.

 The door seal 1 such as that illustrated in FIG. 1 is of a type known per se and comprises in particular a profiled body 3 with a straight U-shaped section which has two lateral branches 5a and 5b, parallel and facing each other , which are joined to each other by a bottom wall hereinafter called heel 7. The seal 1 also comprises at least one profiled lip 9 originating at the heel 7 and which extends from one side of the body 3 coming opposite the lateral branch 5a of said body, and a profiled tubular part 11 ("tubing" in English) which is formed against and along the lateral branch 5b of the body 3. A frame reinforcing metal 13 can be embedded in the body 3 of the seal 1.

 The seal 1 is generally manufactured by extrusion and, in a manner known per se, at least one appearance coating 15 which can be deposited in line on the lip 9 during the seal extrusion phase for example. In the example illustrated in FIG. 1, the coating of appearance 15

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 also covers the heel 7 which forms the base of the lip 9, this lip often being called cosmetic lip.

 As explained in the preamble, certain joints can be subjected, after extrusion, to finishing operations during which the appearance coating 15 can be locally damaged. In other words, the lip 9 forms a fragile part A of the seal 1 which should be protected during the finishing operations of the seal.

 Indeed, as illustrated in FIG. 2, a finishing operation using a tool such as a mold M, it can be seen that the fragile part A of the seal 1 located between the two parts M1 and M2 of the mold M will necessarily undergo thermal and / or mechanical constraints. In the example illustrated in FIG. 3, a mold M is used to connect the two strands 1 a and 1 b of a joint 1 to each other, and it can be seen that their ends which are housed between the two parts M and M2 of the mold M will be subjected to a temperature of the order of 200 C for example to connect them to each other. As a result, the fragile parts A located at the ends of the strands 1 a and 1 b can be damaged during the finishing operation.

 To overcome this drawback and as illustrated in FIG. 4, the invention provides means for at least locally separating the fragile part A of the joint to release it from the remaining part B of the joint during the operations for finishing the joint which will be carried out on this remaining part B. In general, these means are formed during the joint extrusion operation and comprise at least one bridge of material or leg which connects the fragile part A and the remaining part B of the joint.

 According to the exemplary embodiment illustrated in FIG. 4, these means consist of two bridges of material 20 and 22 which are obtained during the operation of extruding the seal 1 by providing a cavity 25 in the heel 7. The two bridges of materials 20 and 22 are substantially located at the two lateral branches 5a and 5b of the body 3 of the joint, and at

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 at least two modes of operation can be considered before proceeding with a joint finishing operation.

 According to the first operating mode as illustrated in FIGS. 5 and 6, the material bridge 20 is sectioned and the other material bridge 22 is used as a hinge to pivot the lip 9 so as to move it away from the heel 7 (figure 5).

 During a joint finishing operation which uses a tool such as a mold M for example, this mold M (FIG. 6) comprises three parts Mi, M2 and M3 which are arranged in such a way that the fragile part A of the seal is located inside the mold M, but the coating 15 is not in contact with the two aggressive parts M1 and M2 of the mold M.

 Once the finishing operation is finished, the seal 1 is removed from the mold M and the fragile part A of the seal at the heel 7 is resolidated at the level of the material bridge 20 which had been cut, by any suitable means, glue or a double-sided adhesive for example, the appearance coating 15 of the lip 9 having remained free.

 According to the second operating mode illustrated in FIGS. 7 to 9, the two bridges of material 20 and 22 are sectioned over part of the length of the joint so that its fragile part A is located outside the mold M, as is illustrated in FIGS. 8 and 9 which respectively repeat the examples of FIGS. 2 and 3. Once the finishing operation is finished, the seal 1 is removed from the mold M, and the fragile part A of the seal at the heel 7 is resolidated two material bridges 20 and 22 which had been cut, by any suitable means, glue or a double-sided adhesive for example. However, to ensure correct positioning of the lip 9 relative to the heel 7, it is advantageous to use a wedge 30 which is interposed between the lip 9 and the heel 7, as illustrated in FIG. 9.

 In the examples illustrated in the drawings, we considered an operation of finishing the joint after extrusion which consists in connecting one

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 to the other two strands of a joint, knowing that such a finishing operation can also consist in carrying out an angle molding or a thermoforming to give a permanent curvature to the joint for example.

 The joint extrusion operation can be a coextrusion operation of at least two materials. Indeed, in the door seal 1 illustrated by way of example in the drawings, the body 3 and the lip 9 of the seal are made of compact rubber for example, while the tubular part 11 is made of cellular rubber for example.

 When the door seal 1 is mounted, its clip-forming body is fitted on a metal rebate of the door frame, its tubular part 11 being intended to ensure the sealing function with respect to the door, while the lip 9 ensures the aesthetics of the passenger compartment side of the vehicle.

 Furthermore, in the examples illustrated in the drawings, it has been considered that the fragile part of the seal is a cosmetic lip covered with an appearance coating, but the invention also applies to a fragile part which may be a lip. or a "tubing" having a sealing function and covered with a functional coating of the anti-abrasion or protection type against ultraviolet rays for example, or an area of a joint on which an adhesion means is deposited such as an adhesive foam which is particularly sensitive to heat and which allows the joint to be fixed on its support not by fitting but by adhesion.

 Of course, the local separation of the fragile part of the joint can be carried out at any location situated along the length of the joint and not necessarily at the ends of the joint as has been illustrated in the drawings.

 Finally, the invention can be applied to all seals of fixed or movable panels such as doors, hoods, safes, sliding or fixed windows in the field of the automotive industry, to portholes and cokpits in the aeronautical industry, or at doors,

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 French windows or sliding doors in the building industry, etc.

Claims (14)

1. Method for manufacturing a seal (1) for a fixed or movable panel, the method being of the type consisting in manufacturing by extrusion a seal (1) comprising a fragile part, such as an appearance or functional coating (15), over at least part of its length, and then performing at least one joint finishing operation, a process which is characterized in that it consists, before carrying out said finishing operation, of separating at least locally the fragile part (A) of the joint to release it from the remaining part (B) of the joint, to perform the finishing operation on the remaining part (B) of the joint to avoid damaging the fragile part (A), and to re-join the fragile part (A) to the remaining part (B) of the joint after the finishing operation.  2. Manufacturing method according to claim 1, characterized in that it consists in providing at least one bridge of material (20) between the fragile part (A) and the remaining part (B) of the joint during the operation extrusion, and to break at least locally the material bridge (20) before performing the finishing operation on the remaining part (B) of the joint.  3. Manufacturing method according to claim 1, characterized in that it consists in producing at least two bridges of material (20, 22) between the fragile part (A) and the remaining part (B) of the joint, and to break at least locally one of the two material bridges before carrying out the finishing operation on the remaining part (B) of the joint.  4. Manufacturing method according to claim 3, characterized in that it consists in providing at least one cavity (25) between the fragile part (A) and the remaining part (B) of the joint to form the two bridges of material ( 20,22) during the joint extrusion operation.  5. Manufacturing process according to claim 3 or 4, characterized in that it consists, before the finishing operation the remaining part (B) of the joint, at least locally breaking one of the two bridges of material (20, 22 ) and use the other material bridge as a hinge to rotate <Desc / Clms Page number 10>  the fragile part (A) of the seal relative to the remaining part (B) of the seal and move it away from the latter.  6. Manufacturing method according to claim 3 or 4, characterized in that it consists, before the finishing operation, at least locally breaking the two bridges of material (20,22) to distance the fragile part (A) of the seal relative to the remaining part (B) of the seal.  7. The manufacturing method according to claim 6, characterized in that it consists, after the finishing operation, of re-securing the fragile part (A) to the remaining part (B) of the joint by interposing a guide wedge (30) between them.  8. Seal for a fixed or movable panel, said seal comprising at least one fragile part (A), characterized in that it comprises means for at least locally separating the fragile part (A) from the remaining part ( B) of the seal and be able to perform an operation on said seal without damaging its fragile part (A).  9. A seal according to claim 8, characterized in that said means consist of at least one bridge of material (20) located between the fragile part (A) and the remaining part (B) of the seal.  10. A seal according to claim 8, characterized in that said means are constituted by at least two bridges of material (20,22) located between the fragile part (A) and the remaining part (B) of the seal.  11. A seal according to any one of claims 8 to 10, characterized in that the fragile part (A) of the seal is a profiled lip (9) coated with an appearance coating (15).  12. A seal according to any one of claims 8 to 10, characterized in that the fragile part (A) of the seal is a lip having a sealing function and covered with a functional coating (15).  13. A seal according to any one of claims 8 to 10, characterized in that the fragile part (A) of the seal is <Desc / Clms Page number 11>  a part on which is deposited an adhesion means such as an adhesive foam or a mastic for example.  14. Seal according to any one of claims 8 to 13, characterized in that it is manufactured according to a process as defined by any one of claims 1 to 7.