FIRE WINDOWS

Abstract: A fire window comprises a panel of Georgian wired glass suspended within a frame by suspension pins extending through holes drilled in the glass so that each pin lies within a complete mesh. When the panel is subject to the intense heat of a fire, the glass softens and sags, but remains suspended within the frame by means of the interaction between the wire mesh and the suspension pins.

Description: "FIRE WINDOWS" The present invention relates to fire windows. Fire regulations may require that certain windows in a building are able to retain their integrity for a predetermined time, for example 1 hour, in the presence of a fire at one side of the window in order to inhibit spreading of the fire- Such windows may be incorporated, for example, in fire-resisting partition walls in the building, or in fire doors. One previously proposed method of retaining the glass in a fire window is by the use of an impregnated self-adhesive foam strip held in place by a glazing bead. This method is not entirely satisfactory, as the glass is likely to distort and fall out in less than the 1 hour required by the Standard Fire Test. It has also been proposed to clamp the glass in position in the frame, with positive clamping pressure being exerted by screws or the like. While this provides an anchorage satisfactory to enable the window to meet the Standard OMPI Fire Test, it does necessitate a relatively heavy and expensive frame construction. According to the present invention there is provided a fire window comprising a frame, a glass panel mounted in said frame, said panel consisting of glass reinforced with wire mesh, and retaining means for retaining the glass panel in the frame, said retaining means comprising a plurality of pins extending through holes formed in the panel at positions such that each hole is bounded from above by a portion of the mesh. In a preferred embodiment of the invention, the holes are drilled through the glass adjacent to the upper edge of the glass with each hole being within a complete portion of the mesh. Advantageously, the holes may be formed within the first complete mesh row nearest to.the upper edge of the glass. An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a schematic cross section through the head portion of a frame of a fire window incorporated within a fire resistant wall; and Figure 2 is a fragmentary perspective view of the upper portion of a wired glass panel mounted within the frame. OMPI There is shown in Figure 1 a section of fire-resistant wall incorporating a fire window. The window comprises a frame, typically composed of galvanised steel sections of hollow construction, set into the wall, only the head portion 2 of the frame being shown in Figure 1. By way of example, the wall shown in Figure 1 comprises opposed layers of plasterboard 4, the edges of which sit into opposed recesses in the upper part of the head portion 2. The lower part of the head portion 2 is formed with a recess to receive. the upper edge portion of a glass panel 6. The head portion 2 may contain a packing, for example of rock wool, in the zone between and adjacent, the plasterboard layers 4, although the zone of the head portion 2.to the side of the glass panel 6 may be left empty to facilitate heat dissipation from the glass when this is desirable. The opposed side and bottom portions of the frame may consist of sections substantially similar to the section forming the head portion. The glass panel 6 is of so-called Georgian wired glass consisting of an open wire mesh 10 embedded within standard window glass. Typically, the glass may be of 6.5 mm thickness with the mesh having a square mesh size of 13 mm. The glass panel 6 is retained in position by being suspended from the head portion 2 by means of pins 12 extending through the glass. More particularly, suspension holes 14 are drilled through the glass panel 16 at spaced intervals across the width of the glass in positions such that each hole 14 lies within a complete square of the mesh 10, such that a transverse strand 10a of the mesh 10 lies above the row of suspension holes 14. Conveniently, the holes 14 will be formed in the mesh squares of the first complete row adjacent to the upper edge of the glass. 5 The suspension pins 12 are carried by a galvanised steel strip 16 of angle section secured to the head portion 2 of the frame. As shown, a horizontal limb of the strip is secured to the underside of the head portion by screws driven into the head portion as 10 indicated diagrammatically at 18 in Figure 1, and the pins 12 project inwardly, in cantilever fashion, from the vertical limb of the strip 16, the pins 12 being arranged at appropriate intervals along the length of the strip 16 so as to pass through the holes 14 in the 15 glass panel 6 and thus to suspend the glass panel 6. The pins 12 may be screwed or welded to the strip 16. Instead of, or in addition to, securing the strip 16 to the head portion 2 by screwing the horizontal limb of the strip 16 to the head portion, the vertical limb of 20 the strip 16 may be screwed to the opposite wall of the head portion fay screws extending through certain of the holes in the glass; in this case, the screws act not only to attach the strip 16 to the head portion 2, but also act as suspension pins for the glass panel 6. The 25 strip 16 may be supplied in relatively short modular lengths with the vertical limb pre-for ed with holes to receive the suspension pins or screws. The suspension strip 16 is preferably enclosed within a bead 20 of angle section to provide a neat finish for the head portion 2, the bead 20 preferably being screwed to the underside of the head portion 2 as indicated diagrammatically at 22 in Figure 1. The side and bottom edges of the glass panel may be held being pinned at one or a plurality of points in a similar manner to that used for suspending the glass from its top edge. Alternatively, the side and bottom edges may be retained by conventional glazing beads. In use, in the event of a fire, as the glass softens and sags under high temperature conditions in excess of, say, 600°C, the upper transverse strand of the mesh is retained on the suspension pins whereby the glass panel tends to be suspended within the frame by means of the mesh. In a Standard Fire Test carried out using 13 mm Georgian wired glass as described, with a suspension point at every fourth mesh across the glass, the required 1 hour fire resistance was achieved on a panel of 1200mm x 1200mm . It is believed that when a suspension point is provided at every second mesh, a fire resistance of two hours could be achieved. Although the invention has been described in relation to a fire window incorporated within a wall, it will be apparent that the invention is equally applicable to fire windows incorporated in fire doors and other environments. _ OMPI , . WIPO

Claims: CLAIMS:- 1. A fire window comprising a frame, a glass panel mounted in said frame, said panel consisting of glass reinforced with wire mesh, and retaining means for retaining the glass panel in the frame, said retaining means comprising a plurality of pins extending through holes formed in the panel at positions such that each hole is bounded from above by a portion of the mesh. 2. A fire window according to claim 1, wherein the window is suspended in the frame by means of the pins. 3. A fire window according to claim 1 or claim 2, wherein at least some of the pins extend through holes formed through the glass adjacent to an upper edge of the panel, with each said hole being within a complete portion of the mesh. 4. A fire window according to claim 3, wherein the pins extending through the holes adjacent the upper edge of the glass are carried by a metal strip secured to a head portion of the frame, said pins extending horizontally through the strip. 5. A fire window according to claim 4, wherein said strip is of angle section having a horizontal limb and a vertical limb, said pins extending through the vertical limb of the strip. 6. A fire window according to claim 5, wherein the horizontal limb of the strip is secured to an underside of the head portion. 7. A fire window according to claim 5 or claim 6, wherein some of said pins consist of screws extending through said glass into an adjacent part of the head portion whereby to secure the strip to the head portion. 8. A fire window substantially as hereinbefore described with reference to the accompanying drawings. OMPI

Inventors: WEXLER JONATHAN B, WEXLER, JONATHAN, B.
Applicants: FIRE RES PTY LTD, FIRE RESEARCH PTY. LIMITED
Application year: 1984
Main classification: E06B5
IPC codes: E06B5