Screwed Fixing of a Retaining or Fixing Member to a Laminated Glazing

1. Field of the Invention

The invention relates to a process for fixing a retaining or fixing member to a laminated glazing with the aid of a screwed assembly passing through the laminated glazing.

2. Discussion of the Background

Screwed assemblies are normally used for monolithic glazings. One or more holes are made in the glazing and two clamping parts are applied to the two faces of the glazing joined together by a screwed assembly passing through the hole or holes. In many cases, such assemblies cause problems for laminated glazings. Under the influence of the clamping forces exerted by the screwed assembly, a creep effect can occur, i.e. a plastic deformation of the thermoplastic interlayer of the laminated glazing in the area around the hole. Thus, the thickness of the laminated glazing contracts in this region, so that the screwed assembly is loosened. The screws, on becoming loose, can lead to a supplementary play on the part of the fixture.

It is an object of the invention to develop a screwed assembly for laminated glazings which reliably avoids the risk of loosening and untimely detachment of the screwed assembly and its process of assembly.

According to the process of the invention, the above and other objects are achieved by providing each of the glass sheets forming the laminated glazing with holes before being assembled with the thermoplastic interlayer. The holes are eccentric with respect to one another following the manufacture of the laminated glazing. The empty space separating parts located within the holes of the screwed assembly and the walls of the holes are filled with a curable plastic adhesive.

By filling with a curable adhesive the space separating the parts of the screwed assembly passing through the holes and the walls thereof, an incompressible abutment is created between the clamping surfaces of the screwed assembly which, after curing, absorbs the clamping forces and prevents the plastic deformation of the thermoplastic interlayer, e.g., during heating caused by solar radiation. Moreover, the eccentric arrangement of the holes with respect to one another prevents any distortion of said abutment within the holes.

As an eccentric arrangement, it is, e.g., possible for one of the holes to have a larger diameter than the other.

In view of the fact that the adhesive used for producing the abutment ensures an adequate bonding with the material of the screwed assembly, the threaded screw and the complementary part of the screwed assembly cooperating therewith are also reliably prevented from becoming loose. The adhesive can be a curable plastic adhesive. It is, e.g., a single-component adhesive or a two-component epoxy adhesive.

According to the invention, the screwed assembly requires a relatively low tightening torque of around 0.5 Nm.

The process according to the invention is particularly effective, e.g., for the durable fixing of guide pins to sliding side windows for cars. It is for this reason that the following description of an embodiment shown in the drawing concerns the fixing of such a guide pin to a laminated lateral glazing.

The sole FIGURE illustrates a section through one embodiment of the invention.

The laminated glazing 1 is constituted by two glass sheets 2,3 assembled with a thermoplastic interlayer 4, e.g., a 0.76 mm thick PVB sheet, via heat and pressure. The laminated glazing 1 is in this example a convex side glazing which slides vertically in a door and which is guided by means of one or more metal pins 6 firmly fitted to the laminated glazing, the pins sliding in rails extending roughly vertically along the glazing frame. For reasons of simplicity the guide rail, with which the guide pin 6 cooperates, is not shown in the drawing.

The guide pin 6 includes the gripping section 7, a circular bearing surface 8 and a hollow cylindrical section 9 provided with an internal thread 10 and which enters the hole 15 in the laminated glazing. The thread 12 of an oval head screw 13 is screwed to the hollow cylindrical section 9.

The glass sheet 2 of the laminated glazing is provided, at the location of the guide pin 6, with the hole 15 and the glass sheet 3 is provided with a hole 16. The diameter of the hole 16 is, in the case shown, larger than that of the hole 15. For example, the diameter of the hole 15 can be 10 mm and that of the hole 16, 12 mm. The holes 15 and 16 are arranged with a slight lateral displacement in such a way that they are eccentric to one another when the laminated glazing has been manufactured.

Between the bearing part 8 and the hollow cylindrical part 9 of the guide pin 6, on the one hand, and the glass sheet 2 in the region of the hole 15, on the other, is a polymer centering sleeve 18. Between the oval head of the screw 13 and the surface of the glass sheet 3 is inserted a cushion plate 19 also made from a suitable polymer.

In order to fix the guide pin 6, the centering sleeve 18 is placed on the hollow cylindrical section 9 of the guide pin 6, and the hollow cylindrical section 9 provided in this way with the centering sleeve 8 is inserted into the hole 15. The space within the wall of the hole 16 is then filled with a curable adhesive. The screw 13 is then screwed into the thread 10 with a relatively low tightening torque of roughly 0.5 Nm and then the adhesive is allowed to cure.

For example, for this purpose use is made of an epoxy adhesive having two components or one component of a thermosetting system. The adhesive cures to form a thermosetting material and, after curing, it forms a solid interlayer in the vicinity of the hole 16.

Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.