GB2202570A - Louver blade - Google Patents

Abstract

A double glazed louver blade (1) providing, in the closed position, good thermal insulation while permitting good through vision, comprises two opposed panes (2, 3), each independently of glass or transparent or translucent plastics. The opposed panes (2, 3) are spaced apart by spacer means at or adjacent the periphery of the double glazed area, including spacers (4, 5) of transparent or translucent material, for example water white silicone, along the longitudinal edges of the double glazed area. The blade has ventilation means providing communication between the air space (9) between the panes (2, 3) and the outside atmosphere. The spacer means may include a hollow section spacer (6, 7) along each lateral edge of the double glazed area with the cavity of the spacer open to the atmosphere and holes in the wall of the hollow section spacer facing the air space providing ventilation to the outside atmosphere. <IMAGE>

Description

Louver Blade The invention relates to a louver blade, in particular a double glazed louver blade, and to a louver incorporating a plurality of such blades.

A louver is an arrangement of parallel slats or blades which, in their open position, admit air but exclude rain and, unless of glass or other transparent material, restrict through vision except in a direction parallel to, or almost parallel to, the slats or blades.

It is known to make louver blades of glass and to arrange the individual blades or slats to rotate about axes parallel to their length between an open position in which they admit air through gaps between them, and a closed position in which the gaps between them are closed.

The use of glass louver blades improves vision and daylight transmission through the louver when the blades are in the open position and also permits through vision when the blades are in the closed position. In the closed position, heat losses through a louver depends on the sealing between adjacent blades and the thermal conduction through the blades. When the blades are of glass, the heat loss could be reduced by using double glazed louver blades so reducing the heat lost by conduction through the blades.

Glass louver blades do not usually have their own individual frames but are mounted in a single common frame at their lateral edges to form, together, a louver. It would be a relatively simple matter to produce a sealed double glazing unit with the same plan dimensions as a simple glass louver blade. Unfortunately, the conventional spacing and sealing means used around the periphery to produce sealed double glazing units are quite bulky so that, if double glazed louver blades were made with such conventional spacing and sealing means, the spacing and sealing means along the longitudinal edges of the blades would be obtrusive in appearance and obstruct a substantial part of the view through the louver when the blades are in the closed position.It would be desirable to have a double glazed louver blade which allows good through vision but is nevertheless not subject to condensation on the surfaces facing the air space within the blade. It has now been found that this requirement can be met by using, as louver blades, double glazed units with a ventilated air space and spacers of transparent or translucent material along the longitudinal edges of the blades.

According to the present invention there is provided a double glazed louver blade comprising two opposed panes, each independently of glass or transparent or translucent plastics, spaced apart by spacer means at or adjacent the periphery of the double glazed area of the blade, including spacers of transparent or translucent material along the longitudinal edges of said area, and ventilation means providing communication between the air space between the panes and the outside atmosphere.

The ventilation of the air space prevents condensation from forming on the surfaces facing the air space and obstructing the view. Moreover, because the unit is ventilated, it is not necessary for the spacers between the panes to prevent the transmission of water vapour or be hermetically sealed to the panes. In consequence, spacers which are narrow in comparison with the spacing and sealing means used in conventional sealed units can be used. Preferably, the spacers along the longitudinal edges of the double glazed area have a width not exceeding 5 mm. Moreover, while said longitudinal spacers may be, for example, of glass or transparent or translucent plastics, they are preferably formed from a transparent or translucent polymer.It is not necessary for the longitudinal spacers to be rigid and it is preferred to use polymers that are resilient and have a modulus of elasticity of at least 0.2 MPa, preferably a modulus of elasticity in the range 0.35 MPa to 0.5 MPa; silicone polymers are especially suitable. In a particularly preferred embodiment of the invention, the spacers along the longitudinal edges of the double glazed area are of water-white silicone.

The spacers along the lateral edges of the louver blades in accordance with the invention may be opaque and are conveniently of hollow section material, especially metal alloy or plastics. Thus, in a preferred embodiment of the invention, the double glazed louver blade includes a spacer of hollow section along one or each lateral edge of the double glazed area. The air space between the panes is ventilated to the outside atmosphere; the ventilation may be accomplished by a duct or gap in one or more of the spacers between the panes. In a preferred embodiment, the air space is ventilated to the outside atmosphere through holes in the wall facing the air space of a hollow section spacer along a lateral edge of the double glazed area, the cavity of said spacer being open to the atmosphere.

The louver blade may additionally comprise means for mounting the blade in a louver, for example, U-section strips fitting over the lateral edges of the blade.

The invention is illustrated but not limited by the following description with reference to the accompanying drawings in which: Figure 1 is a front elevation of a double glazed louver blade in accordance with the invention, Figure 2 is a plan view of the louver blade shown in Figure 1, Figure 3 is a sectional view, on an enlarged scale, along the line 111-111 shown in Figure 2, and Figure 4a is a diagrammatic side elevation of a number of louver blades according to Figures 1 to 3 arranged in parallel relationship in the closed position.

Figure 4b is a diagrammatic side elevation, similar to Figure 4a, in the open position.

Referring to Figures 1 to 3 of the drawings, a double glazed louver blade generally designated 1 comprises two opposed panes 2 and 3 of glass, for example 4 mm or 6 mm float glass, both panes having the same longitudinal dimension but one of the panes, 3, being wider than the other pane and forming a flange along the lower longitudinal edge of the blade as shown in Figures 1 and 3.

The panes are spaced apart by spacer means comprising spacers 4, 5 of translucent material along the longitudinal edges of the double glazed area of the blade, and spacers 6, 7 of hollow rectangular section along each lateral edge of the double glazed area.

The spacers 4, 5 along the longitudinal edges are of Arbosil 1082, a water-white silicone sealant having a modulus of elasticity of 0.4 MPa in cured form, available in commerce from Adshead Ratcliffe of Belper, Derbyshire,#England. The spacers 4, 5 each have a thickness equal to the gap between the panes, for example 8 mms, and a width of 3 to 4 mms, so that, despite the fact that the cured silicone has a refractive index different to that of air, the spacers cause only a very limited disturbance to vision through the louver blade. The spacers 6, 7 are relatively rigid, being of square section aluminium alloy, and have a thickness of 8 mms and a width of 8 mms. The spacers 6, 7 are similar to one another, each having a row of holes 8 in the wall facing the air space 9 between the panes, and being adhered to the panes by an adhesive (for example a silicone adhesive or an expoxy adhesive) between the spacer walls and the adjacent faces of the panes. The cavities of the spacers 6, 7 are open to-the atmosphere (as shown in Figure 2) so ventilating the air space 9 between the panes to the outside atmosphere via the holes 8. The spacers 6, 7 are relatively rigid and provide the necessary mechanical strength to space the two panes from one another, the longitudinal spacers 4, 5 serving mainly to occupy the space between the edges of the panes so preventing ingress of dirt, moisture and other foreign matter into the air space between the panes.

The cavities in the hollow section spacers 6, 7 may contain a filter material, for example an inorganic wool such as glass fibre wool (not shown in the drawings), to remove dirt from the air flowing from the outside atmosphere through the spacer into the air space 9 of the unit, and to prevent insects entering the air space.

The spaced panes of the louver blade are mounted in U-section strips 10,11 for example of aluminium alloy fitting over the panes along the lateral edges of the blade. The strips 10 and 11 serve as mounting means for the blade. The U-section strips may be mounted in U-shaped brackets (not shown) carried in the rotation mechanism of a louver.

Double glazed louver blades in accordance with invention can be made by arranging two panes of glass or plastics in parallel spaced relationship separated by temporary longitudinal spacers between them close to the longitudinal edges of the area of overlap between the panes. A curable silicone sealant is then injected into the channels defined inner faces of the panes and the outer faces of said temporary longitudinal spacers. The silicone sealant is then allowed to cure and the temporary longitudinal spacers removed from between the panes. The said longitudinal spacers preferably have a non-stick surface to avoid adhesion of the silicone sealant.When the permanent longitudinal spacers have cured and the temporary spacers have been removed, lateral spacers, pre-drilled as shown in Figure 3 to provide the required ventilation of the air space, may be inserted and glued in position as shown in the drawings.

Figures 4a and 4b show, in diagrammatic form, a plurality of double glazed louver blades arranged in parallel spaced relationship to form a louver. Each of the louver blades, generally designated 1, is mounted for rotation about an axis 12 parallel to the length of the blade between an open position as shown in Figure 4b in which the louver admits air through the gaps between the blades, and a closed position as shown in Figure 4a in which the gaps between the blades are closed. As shown in Figure 4a, the flange formed by the lower edge of outer pane 3 extending beyond inner pane 2 of one blade overlaps the upper margin of the outer pane 3 of the blade immediately below when the blades are in the closed position.The louver blades are mounted in U-sectioned capping strips 11 along the lateral edges of the blades; the capping strips are rotatably mounted in the frame (not shown) of a louver in a similar manner to that known for single glazed glass louver blades. To reduce draughts when the louver blades are in the closed position, some form of sealing means (not shown) may be incorporated in the individual louver blades to provide a seal between them. Such sealing means may be constituted by a flap anchored in the lower longitudinal spacer and extending therefrom so that it engages between the upper edge of one louver blade and the flange formed by the outer pane of the louver blade above.

Alternatively, the longitudinal spacer along the upper edge of the louver blade may extend above the edge of the outer pane of the blade and engage against a flange formed by the outer pane of the louver blade above; or the inner pane of the louver blade may extend above the longitudinal spacer along the upper edge of the louver blade so forming a flange which engages against the otherwise exposed inner face of the inner pane of the louver blade above.

It will be appreciated that it is not necessary for either or both panes of the louver blades to be of clear glass, and they may be, for example, of transparent or translucent plastics or of patterned or solar control glass. For example, the inner pane may be of patterned glass and/or the outer pane may be of solar control glass, such as ANTISUN body coloured glass, containing one or more heat absorbing metal oxides (ANTISUN is a trade mark of Pilkington Brothers plc).

The present invention enables double glazed louvers, with greater heat insulating properties than conventional single glazed louvers to be produced without significantly detracting from the appearance of the louvers and while maintaining good visibility through the louvers.

Claims (10)

Claims

1. A double glazed louver blade comprising two opposed panes, each independently of glass or transparent or translucent plastics, spaced apart by spacer means at or adjacent the periphery of the double glazed area of the blade, including spacers of transparent or translucent material along the longitudinal edges of said area, and ventilation means providing communication between the air space between the panes and the outside atmosphere.

2. A double glazed louver blade as claimed in claim 1 wherein the said spacers of translucent or transparent material are of silicone.

3. A double glazed louver blade as claimed in claim 2 wherein the said spacers are of water-white silicone.

4. A double glazed louver blade as claimed in any of the preceding claims wherein said spacers of translucent or transparent material have a width not exceeding 5 mm.

5. A double glazed louver blade as claimed in any of the preceding claims wherein said spacers of translucent or transparent material are of silicone formed into strips and allowed to cure in situ between the panes.

6. A double glazed louver blade as claimed in any of the preceding claims including a spacer of hollow section along one or each lateral edge of the double glazed area.

7. A double glazed louver blade as claimed in claim 6 wherein the air space between the panes is ventilated to the outside atmosphere through holes in the wall of said hollow section spacer facing said space, the cavity of said spacer being open to the atmosphere.

8. A double glazed louver blade as claimed in any of the preceding claims which additionally comprises mounting means for mounting the blade in a louver.

9. A double glazed louver blade substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

10. A louver comprising a plurality of double glazed louver blades as claimed in any one of preceding claims mounted in parallel relationship for rotation about spaced parallel axes between an open position in which they admit air through the spaces between them and a closed position in which the spaces between them are closed.