GB2120775A

GB2120775A - Louvre assemblies

Info

Publication number: GB2120775A
Application number: GB08210994A
Authority: GB
Inventors: Malcolm Whitehead
Original assignee: MCKENZIE MARTIN Ltd
Current assignee: MCKENZIE MARTIN Ltd
Priority date: 1982-04-15
Filing date: 1982-04-15
Publication date: 1983-12-07
Also published as: GB2120775B

Abstract

In a louvre assembly e.g. part of a roof ventilator, the leading edge of each blade is provided with a gutter 9 which is defined by walls disposed inwardly of the plane of the blade when considered in the closed condition such that adjacent blades in said closed condition overlap to produce a generally flat appearance. <IMAGE>

Description

SPECIFICATION Improvements in or relating to louvre as sembrles This invention relates to a louvre assembly of the kind comprising an array of louvre blades movable between a closed position in which the blades overlap and a fully open position in which the blades are arranged in generally parallel relationship.

It is known to use such louvre assemblies in the construction of ventilators of all kinds including fire vents. The array of louvres provides a closure preventing weather entry into the ventilation opening, which is particularly important when the ventilator is mounted on a flat roof.

It has long been known to reduce water penetration between the closed blades by turning over the leading edge of each blade (i.e. the edge that is directed into the ventilation opening in the open position) to provide a gutter on the outside of the blade as considered in its closed position. A corresponding channel section is provided on the inside of the blade at its opposite or trailing edge. The arrangement is such that when the ventilator is closed the trailing edge of the blade with its inwardly directed channel overlaps the outwardly directed channel of the leading blade edge to form an enclosed duct which collects any water that does penetrate between the blades and drains it at the sides of the ventilator opening.

More recently, such a design has been adapted specifically for use on a flat roof. This design is described in U.K. Patents Nos.

1 393872 and 1 393873 by Colt International Ltd. and is generally satisfactory although it does have a number of disadvantages. Because of the disposition of the edge channels at opposite sides of the closure blade a stepped appearance of the closed assembly is inevitable with each blade sloping downwardly to its leading edge. Water is thus encouraged to run into the blade gutters which have to be dimensioned accordingly and which may become obstructed by sediment and other extraneous matter. In addition, the obstruction to air flow afforded by each blade in the open position is substantially increased (as compared to a flat blade) because the channels are disposed at opposite sides of the blade.

It is an object of the present invention to obviate or mitigate the aforesaid disadvantages.

According to the present invention there is provided a louvre assembly of the kind defined wherein the leading edge of each blade is provided with a gutter which is defined by walls disposed inwardly of the plane of the blade when considered in the closed condition such that adjacent blades in said closed condition overlap to produce a generally flat appearance.

Preferably, the trailing edge of each blade is folded back on itself to terminate in an inwardly angled flange which overlaps a side wall of the gutter of the adjacent blade in the closed condition.

The invention will now be further described by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view from above of a roof ventilator including a louvre assembly of the kind with which this invention is concerned; Figure 2 is a sectional view to an enlarged scale illustrating the louvre construction, and Figure 3 is a view in the direction of the arrow A in Fig. 2.

Referring now to the drawings, a ventilator 1 intended to be mounted on a flat roof comprises a mounting plate 2 to which is attached a generally rectangular casing 3, the open top of which is closed by an array of overlapping louvre blades 4 covering a ventilation duct not shown. The blades 4 form part of an assembly additionally comprising respective pivot axes for the blades and an operating mechanism for pivoting the blades in unison between the open and closed positions. Apart from the blade configuration the construction of the louvre assembly is well known and is not further described or illustrated.

Each louvre blade 4 comprises a flat central portion 5 with depending side cheeks 6 and 7 having openings 6', 6" and 7', 7" for mounting and operating the blade respectively. The right-hand edge of each blade 4 as seen in Figs. 2 and 3 is directed downwardly into the ventilation duct in the open position and may therefore be referred to as the leading edge 4a, the opposite edge being called the trailing edge 4b. These edges 4a, b overlap when the blades 4 are closed.

The leading blade edge 4a is shaped into a triangular-section channel 8 with two side walls 9, 10 and a reverted lip 11 at its outer side. The lip 11 is coplanar with the central blade portion 5 but the side walls 9, 10 are located to the inside of the blade. The channels 8 are overlapped by the trailing edges 4b of adjacent blades 4. Each trailing edge 4b is folded back to provide a double-thickness border section 1 2 which terminate in an angled flange 1 3 which rests against the inside wall 9 of the channel 8.

Because the profiles at the leading and trailing edges 4a, b of the blades 4 both project inwardly of the first central portions 5 the blades 4 overlap to provide a generally flat appearance. Drainage can thus be achieved to a substantial extent by run-off from the blade surfaces and water that does penetrate between the blades is drained by the channels 8 over the side cheeks 6, 7 and into drainage ducts (not shown) in the casing 3. The drainage ducts in the closed position of the louvre blades form a fully enclosed internal gutter thus preventing to a large ex tent extraneous matter entering or blocking the drainage ducts. Since there are no projec tions to the outside of the blades 4 the obstruction to air flow presented by the blades in the open position is small.

The blades may be made of sheet metal, e.g. aluminium alloy, that can be cut and bent into shape. Alternatively, the blades may be made of any other suitable material, e.g.

moulded plastics.

It will be appreciated that a louvre assembly according to the invention may find a variety of different applications and is not confined to roof-mounted ventilators. For example, a ven tilator using a louvre assembly of the inven tion may be mounted in an inclined or vertical plane.

Claims

1. A louvre assembly of the kind defined wherein the leading edge of each blade is provided with a gutter which is defined by walls disposed inwardly of the plane of the blade when considered in the closed condition such that adjacent blades in said closed condi tion overlap to produce a generally flat appearance.

2. An assembly as claimed in claim 1, wherein the trailing edge of each blade is folded back on itself to terminate in an in wardly angled flange which overlaps a side wall of the gutter of the adjacent blade in the closed condition.

3. An assembly as claimed in claim 1 or 2, wherein the gutter is of triangular section -partly covered by a reverted lip at its outer side.

4. A louvre assembly substantially as herein described with reference to and as illustrated in any one of the preceding claims.

5. A ventilator incorporating a louvre as sembly as claimed in any one of the preced ing claims.