GB2440042A

GB2440042A - Glazing structure comprising pane adhesively bonded to a base which is removably fixed to a structure

Info

Publication number: GB2440042A
Application number: GB0713310A
Authority: GB
Inventors: Daniel Riout
Original assignee: Saint Gobain Glass France SAS; Compagnie de Saint Gobain SA
Current assignee: Saint Gobain Glass France SAS; Compagnie de Saint Gobain SA
Priority date: 2006-07-11
Filing date: 2007-07-10
Publication date: 2008-01-16
Anticipated expiration: 2027-07-10
Also published as: DE202007009598U1; GB2440042B; ITMI20071364A1; BE1017413A3; KR20080006481A; KR101435983B1; FR2903723A1; GB0713310D0; FR2903723B1

Abstract

A glazing arrangement comprises a substrate 1 which is at least partially transparent, at least a part of the periphery of a first face of this substrate 1 being joined to a base 2 by a structural bond 3, such as an adhesive, the said base 2 being removably fixable to a structure 7. The base may project beyond the periphery of the substrate and comprise an aperture 5 for accepting bolts 6 used to attach the base 2 to the structure. The glazing arrangement may be used for glazing for a vehicle such as a train. Methods for fitting and dismounting the substrate 1 are also disclosed.

Description

WINDSCREEN FOR QUICK FITTING

The present invention relates to the fitting of glazing which has high strength, and which is therefore relatively thick and heavy, particularly into bodywork openings. Such glazing includes the front windscreeris of high speed trains. It is known that the problem of this fitting lies in the excessive period of immobilization of the vehicle which it requires. The time required to replace a front windscreen of a high speed train can be as little as one day or even two hours.

The glazing with which this patent is concerned is, for example, laminated glazing having three or four plies (or sheets) of glass joined together by interleaved layers of adhesive such as polyvinyl butyral (PVB) or polyurethane (PU) . The sheets of float glass can be hardened or tempered.

Several methods are used for fitting this glazing.

In a first method, the glazing is fitted in the bodywork by a bond which has both a structural and a sealing function. In this case, the dismounting time is excessive.

In a second method, a silicone gasket is injected around the glazing so as to cover its edge and the periphery of its two main faces. The encapsulated product formed in this way has projecting lips. When it is fitted to the train, the glazing is held by clamping between a main frame and a retaining piece screwed on to the latter. The retaining piece compresses the lips, thus providing a seal. The main frame is fixed to the bodywork by a structural bond. This method has the drawback of the high cost of the frame, the retaining piece and the silicone gasket injection mould.

A third method differs from the second in that the retaining piece is eliminated. The glazing is bonded to a frame which is fixed (by bolting for example) to the bodywork. The adhesive has the double function of fixing the glazing (the structural function) and providing a seal between the frame and the glazing. The disadvantage is that the sealing with respect to the structure has to be carried out at the time of fitting and the cost of the frame is still high.

The invention has been devised to overcome these disadvantages. For this purpose, it proposes a substrate which is at least partially transparent, at least a part of the periphery of a first face of this substrate being joined to a base by a structural bond, the said base being fixable to a structure.

Furthermore, the structural bond of the glazing is prefabricated and requires no drying time at the time of fitting. The fitting is carried out very quickly by mechanical fixing, for example by bolting the base to the bodywork. The gasket requires a much shorter drying time than a structural bond. The time required to replace a front windscreen of a high speed train is considerably reduced (not more than two to five hours).

The base can be continuous and can cover the whole periphery of the substrate. However, if the substrate has a complex shape, having a double curve for example, the base advantageously consists of a plurality of separate elements which do not cover the whole of the said periphery of a first face of the substrate. This characteristic makes it possible to shape relatively small, and more or less flexible, base elements to match this complex shape of the substrate. Furthermore, the desired fixing of the glazing, which is relatively demanding because of the weight of the glazing and the high speed of the vehicle, can be achieved perfectly with these base elements which leave peripheral fractions of the substrate uncovered.

The base preferably comprises at least one metal or composite flat piece, made, in particular, from aluminium or a mixture of resin and reinforcing fibres such as glass fibres. This parallelepipedal shape which is easily formed is entirely suitable for the substrate according to the invention, particularly in the case in which the base is composed of a plurality of separate elements.

In a particularly practical embodiment, the base has holes intended to receive screws for fixing the said substrate to the said structure.

In a first variant, the base projects beyond the substrate, and its projecting part has the said holes passing through it. Thus, during assembly, the said first face of the substrate including the base is orientated towards the bodywork opening. The position of the substrate with respect to the opening is adjusted by aligning the hole or holes of the projecting part of the base with a corresponding hole or holes in the bodywork. The screws are inserted through the side of the second face of the substrate opposite the side carrying the base.

In a second variant, the said holes have a thread or any equivalent means. The term "equivalent" is to be interpreted as meaning a shape serving to secure a fixing by locking an element of complementary shape. It is then possible to fit the glazing by inserting the screws or equivalent means through the face of the bodywork farthest from the base, and then fixing into the base through the bodywork. In this variant, therefore, the base cannot project beyond the substrate.

It should be noted that, if the said base is composed of a plurality of separate elements, they can all be shaped according to the first variant, or all according to the second, or alternatively some can be shaped according to the first and others shaped according to the second.

The invention also proposes a method for fitting a substrate as described above to a structure, this method comprising fixing the said base to the said structure. The base is fixed in contact with the face of the bodywork orientated towards the outside of the vehicle. The substrate is fitted from the outside of the vehicle, a procedure which is practical and quick.

The invention also proposes a method for dismounting a substrate as described above which is fitted to a structure, this method comprising the detachment of the said base from the said structure. This detachment includes, for example, unscrewing or an equivalent operation, followed by the separation of the substrate towards the outside of the vehicle.

The operations of screwing and unscrewing are carried out according to the first and/or the second variant detailed above.

As a general rule, the dismounting of the substrate comprises the removal of the gasket between the outer face of the said substrate and that of the said structure. Similarly, fitting comprises the formation of such a gasket.

However, the replacement of a substrate according to the invention does not necessarily rule out the re-use of the existing gasket, particularly where the substrate is fitted by screwing through the bodywork into a non-projecting base.

The invention also proposes: -glazing composed of a substrate as described above, comprising one sheet or preferably a plurality of sheets of glass, particularly three or four, joined together by means of interleaved layers of adhesive such as polyvinyl butyral (PVB) or polyurethane (PU); -the application of this glazing to a vehicle for land, air or sea transport, particularly to form the front glazing for a train.

The invention is illustrated by the following example with reference to the single attached figure, which is a schematic sectional view of front glazing for a high speed train, fitted in its bodywork opening.

Example

The glazing 1 is composed of four sheets of soda-lime float glass bonded to each other by polyvinyl butyral adhesive layers which are not shown. In other embodiments, the laminated glazing can have more than one sheet of polycarbonate bonded to the glass by a layer of polyurethane.

On discrete and separate parts of its perimeter, the glazing 1 is provided with projecting bases 2, composed of aluminium flat pieces which are parallelepipedal and whose shape is adapted to the curvature of the glazing.

The base 2 is joined to the glazing 1 by a structural bond 3 composed of single-or double-component polyurethane adhesive. This bond is prefabricated; in other words, the polymerization and drying of the adhesive are advanced to a sufficient degree when the glazing is fitted, thus obviating any additional waiting period before the train is despatched.

The base 2 has a projecting part 4 having through holes so that it can be fixed by means of screws 6 to the bodywork structure 7.

The bodywork comprises an outer face 8 in contact with the atmosphere, an inner face 9 and a recess 10 compensating for the total thickness of the glazing 1, the structural adhesive 3 and the base 2, in such a way that the outer surface of the glazing 1 lies flush with the outer surface 8 of the bodywork 7.

The space between the edge of the glazing 1 and the bodywork 7 is filled to provide sealing against pressure waves and water, by means of a gasket 11, for which various materials can be used, including polyurethane, particularly double-component polyurethane, silicone, and MS polymers. MS polymers are polyethers terminated with silyl groups. A non-exclusive example of such an MS polymer is the polymer formed by a polyoxypropylene chain terminated with dimethoxysilyl groups. Because of the absence of cohesive segments in their main chains, these polymers have high flexibility and frequently do not require the addition of plasticizers or even solvents.

The sealing gasket or bond is formed at the time of fitting to the train. Present-day adhesives such as those mentioned above allow rapid setting, and therefore enable the train to be used after a few hours.

The fitting, dismounting and replacement of the glazing 1 shown in the single figure are carried out from the outside. It is simple and quick.

The cost of the frame (bases) is minimized, and this component can therefore be destroyed during dismounting.

A small number of components, which are relatively simple in technical terms, are used.

The time required for the replacement of front glazing for a high speed train according to the invention is considerably reduced; only a few hours are required before the train can be restarted.

Claims

CLAIMS

1. Substrate (1) which is at least partially transparent, at least a part of the periphery of a first face of this substrate being joined to a base (2) by a structural bond (3), the said base (2) being fixable to a structure (7)
2. Substrate (1) according to Claim 1, characterized in that the said base (2) is composed of a plurality of separate elements which do not cover the whole periphery of a first face.

3. Substrate (1) according to one of the preceding claims, characterized in that the said base (2) comprises at least one metal or composite flat piece.

4. Substrate (1) according to one of the preceding claims, characterized in that the said base (2) has holes (5) for receiving screws (6) for fixing the said substrate (1) to the said structure (7) 5. Substrate (1) according to Claim 4, characterized in that the said base (2) projects beyond the said substrate (1), and its projecting part (4) has the said holes (5) passing through it.

6. Substrate (1) according to Claim 4, characterized in that the said holes (5) have a thread or any equivalent means.

7. Method for fitting a substrate (1) according to one of the preceding claims to a structure (7), characterized in that it comprises fixing the said base (2) to the said structure (7) 8. Method for dismounting a substrate (1) according to one of the preceding Claims 1 to 6 which has been fitted to a structure (7), characterized in that it comprises detaching the said base (2) from the said structure (7) 9. Glazing composed of a substrate (1) according to one of Claims 1 to 6, comprising a sheet or preferably a plurality of sheets of glass joined together by means of interleaved adhesive layers.

10. Application of glazing according to Claim 9 to a vehicle for land, air or sea transport, particularly to form the front glazing for a train.