APPARATUS AND METHOD FOR SECURING A PANE AGAINST IMPACT

Field of the invention

The present invention relates to films for panes of transparent material, in particular, but not limited to, window films for tempered glass, and methods of application of such films to glass panes.

Background of the invention

It is known to apply window safety film (hereinafter referred to as "window film") to a face of window and door panes to prevent glass shattering. Such window film consists of a layer or layers of thin polyester adhesive film, which is applied to the inside surface of the glass (or transparent plastics sheet) to improve impact resistance, and also to hold loose shards of glass together when the glass is broken on impact or spontaneous breakage, hereinafter called NSI (nickel sulphide inclusion), which occurs in toughened or tempered glass.

Such window films will reduce bomb blast injuries, since the film holds the loose shards together and the whole window pane will drop to the ground as one piece rather than hundreds of shards. Similarly, such films are extensively used in schools and hospitals to resist falling body impact, e.g. where persons trip and fall against non safety-rated glass. The glass shatters, but it does not disintegrate into multiple shards, because the window film holds the shards together.

It is known that the broken glass and window film can be held in place in the window frame in the event of breakage through impact or NSI, by either:-

a) wrapping the window film onto the frame and clamping the film by using a clamping profile where the system is attached by screws, (GB2 327 700 B); or

b) by attaching the window film to the glass by using a rigid or flexible profile system where the attachment method used is adhesive tapes, silicones or adhesives (e.g. as shown in GB 2 374 893 B).

A problem is that many window constructions do not have window frames but hold the glass in place by using bolted systems, a system known as "planar" being a typical example. Typically the glass is drilled through during the manufacturing process and then toughened or tempered by reheating and rapid cooling. The glass is then held in place by normally four or six bolts through the glass pane which are then in turn attached to the structure of the building. In this situation there is no frame to attach the window film to prevent the broken glass from falling out. It is also known that removing the bolt fittings can result in the weather seals failing and the glass breaking due to the removal and refitting.

The present invention seeks to overcome or ameliorate at least one of the problems of the prior art; or provide a useful alternative

Summary of the invention

The present invention seeks to provide an anchoring attachment which will hold the glass and window film to the bolts holding the window in place against impact and NSI and which can be installed as a retrofit to existing glass without the necessity to remove the glass.

An aspect of the present invention provides a washer for application to a window film around a bolt mounting securing a pane of glass without removal of the pane of glass during application of the washer. In an aspect, the window film may be applied without removal of the pane of glass. In an aspect, the washer has a central hole, allowing it to be mounted to the window film around the mounting, which passes through or is otherwise attached to a face of the pane of glass. In an aspect, the washer has a split in it from the hole to an outer edge of the washer. The washer may have more than one split. The washer may be flexible. The washer may comprise polyester material. The

window film may also have a hole, for allowing it to be mounted to the pane of glass without removal of the glass from the mounting.

According to an aspect, there is provided apparatus for securing a bolt mounted pane of glass against disintegration without removal of the glass, the apparatus comprising a window film, for adhesion to the glass pane, the film comprising at least one hole therein and a split extending between the hole and an outer edge of the film, the film being configured to allow adhesion of the film on the pane around a securing bolt therethrough without removal of the pane, and a washer comprising a hole and a split between the hole and an outer edge of the washer, the washer being configured to allow mounting of the washer on the mounted film around the securing bolt, with the washer covering the at least a part of the split in the film.

Detailed Description of Embodiments of the Invention

An embodiment of the present invention will now be described, purely by way of example, with reference to the accompanying drawings, in which:

Figure 1 shows a side view of a glass panel and attachment system according to an embodiment of the invention;

Figure 2 shows a top view of the glass panel of Figure 1; and

Figure 3 shows a washer for use in the embodiments of the present invention.

Figure 1 shows a pane of glass 100 which is mounted to a bolt mounting 110. The bolt mounting 110 comprises a body 112 an outer and inner flanges 114, 116, which are attached to the body 112 on either side of the pane of glass 100 with an outer dimension larger than that of a hole 105 in the pane of glass 100, through which the body 112 of the bolt mounting 110 passes. The outer and inner flanges 114, 116 therefore abut opposing faces of the pane of glass 100 and hold it into position relative to the bolt mounting 110.

The hole 105 in the pane of glass 100 is generally approximately the same size as the body 112 of the bolt mounting 110 which passes therethrough. The pane of glass 100 is tempered, which makes it prone to breakage when removed from the bolt mounting 110. Further, weather seals around the bolt mounting 110 and at the edges of the pane of glass 100 (not shown) are also damaged on removal of such a pane of glass 100.

The glass 100 has a window film 120 adhered to it. The thickness of the window film 120 may be 150 microns. Thicker films may also be used. Thinner films may be used alternatively. The window film 120 is, in the present embodiment, made from polyester, although other suitable materials (which may be completely, or partially, transparent) may be used. The window film 120 is attached directly to the glass with a hole provided therein to accommodate the inner flange 116 so that the window film can be applied to the glass without removal of the inner flange 116. The window film 120 has a self-adhiesive on one side in the present invention, although it could be applied separately, or provided on the glass 100.

The window film 120 comprises a split 126 in the material extending from each hole 105 to an outer edge of the window film 120. Each split 126 allows the window film to be placed around the bolt mounting 110 without removal of the pane of glass 100 from the bolt mounting 110, while retaining the window film in a single piece.

A washer 130 is provided. The washer 130 is mounted on the window film on the opposing side to the pane of glass 100. The washer 130 extends around the bolt mounting 110 and, in the present embodiment, is adhered to the window film using silicone (in particular, Dow Corning 995 structural silicone may be used). However, other adhesives or mounting techniques might also be used. The washer 130 is, in the present embodiment, made from polyester and is flexible. The washer is substantially annular and comprises a slit 135 (Figure 2) extending from an inner hole 133 to an outer edge. As the washer 130 is flexible, it can be placed around the bolt mounting and onto the window film 120 without removal of the glass 100 from the bolt mounting 110, and adhered in place as required. The washer may alternatively have self adhesive placed on one side or both sides.

As shown in Figure 2, the split 126 of the window film 120 extends in one direction from the hole in the window film 124, while the slit 135 in the washer 130 extends in a different direction from the hole in the washer. The hole in the washer and hole in the window film are substantially the same size, as they both must provide sufficient space for the body 112 and inner flange 116 of the bolt mounting 110. hi this way, the split 126 of the window film 120 is covered by the washer 130. Thus, separation of the two edges of the split 126 of the window film 120 is protected against by the material of the washer 130, as well as the adhesion of the window film to the glass (which is removed if the glass breaks. Although not shown, the split in the washer may extend from the hole towards the centre of the pane, so that the split 135 extends in the same direction as stress lines in the pane of glass 100.

In an alternative embodiment, the washer may comprise two separate halves of an annulus which are placed around the inner flange of the bolt mounting. The two splits formed by the edges of the two halves are then arranged so that neither of them is aligned with the split in the window film. A further pair of split washer halves may then be placed on top of the first pair with the splits formed where the two halves join, in a different rotational alignment around the inner flange to that of the first pair of halves. In such an embodiment, the washer or washers may be rigid, rather than flexible, as no bending of the washer halves is required to mount them on the window film. In each embodiment, the split extending from a hole in the window film is covered by the washer and a split in the washer does not align with a split in the window film.

The present invention has been described purely by way of example and various modifications and/or additions may be made and would be apparent to the person skilled in the art and fall within the scope and spirit of the invention.

Any discussion of the prior art throughout the specification is not an admission that such prior art is widely known or forms part of the common general knowledge in the field.

Unless the context clearly requires otherwise, the words "comprise", "comprises", "comprising" and the like are to be interpreted in an inclusive, rather than exclusive or exhaustive; that is to say, in the sense of "including but not limited to".