GB2276235A - Ventilators - Google Patents

Abstract

A ventilator unit consists of an internal flap and an external louvre grille (40) for mounting respectively on the inside and outside of a window frame. The inner edges of the louvres (48) are located spaced from the frame surface, and the inner edge of the lowermost louvre has a set of downwardly directed teeth (50) forming a comb and adjacent hut spaced from the frame surface. The teeth (50) act to direct rainwater drops down and reduce the risk of water or insect entry into or through the window frame. The louvres (48) are held in place by integrally moulded bars (46) which contact the window frame. The flap is held in fully open and closed positions by plastics spring members (4, Figs. 6, 7 not shown). <IMAGE>

Description

VENTILATORS This invention relates to ventilators.

In order to comply with modern building regulations, it is necessary to install ventilators in buildings. These allow the passage of air from the inside of the building to the outside or vice versa for a variety of well-known purposes. It is, however, desirable that ventilators should permit only air to pass through them.

Specifically, it is undesirable that insects can easily pass through them and it is also very undesirable that ventilators should allow rainwater to pass from the exterior of the building to the inside. Numerous ventilator designs have incorporated features to prevent either of these phenomena occurring.

Modern building construction and architectural practice has long moved away from the use of airbricks set in walls. Instead, for constructional and aesthetic reasons, ventilation has been incorporated into window frames, which are installed in apertures in the structural walls of a building anyway. However, particular problems arise in the area of ventilators incorporated into window frames. These are desirably of low profile and low visual impact, and must not affect the operation of the window. Generally speaking, the ventilation aperture is a simple slot, e.g. through a wooden or plastics window frame member which is provided with an internal closable flap and, on the outside, with some sort of screen.

A problem with many known designs of such ventilator units is that, if the flap is open on the inside and it is raining outside, and with the air pressure in the interior of the building being lower than that outside, for example due to the direction of the wind, there is a marked tendency for water to be drawn in through the aperture when it is raining, and thus to penetrate either into the window frame itself, or into the room, or both.

Any such penetration is undesirable.

According to the present invention, there is provided, in a ventilator unit having an internal ventilator flap and an external louvre unit, e.g. for attachment to opposite sides of a window frame the improvement which comprises constructing the external louvre unit in the form of a set of downwardly inclined louvres with their roomwards edges held away from the window frame member and wherein, adjacent the roomwards edge of the lowermost louvre member, there is provided a generally downwardly directed comb, the free ends of the teeth of which are arranged to lie adjacent but slightly spaced from the window frame.

By suitably dimensioning the pitch of the louvres of the louvre section and the teeth of the comb, the ingress of flying insects may be prevented. Even with quite severe air throughflow from the outside to the inside, water is found not to pass into the aperture in the window frame, but rather to be fed down the teeth of the comb to form drops which then fall downwardly rather than being blown into the aperture in the window frame member.

Both the flap vent member and the louvre member of ventilators in accordance with the present invention are preferably constructed from plastics materials, e.g., by injection moulding. They may be affixed to the respective sides of the window frame by any convenient means, for example by having appropriate apertures for the receipt of fixing screws. The dimensions of the units will be chosen depending upon the dimensions of the aperture, usually a slot, through the window frame through which air may pass. Preferably the louvres extend from slightly above the slot to a position no higher than the base of the slot, with the teeth of the downwardly directed combs lying all below the slot when the louvre unit is installed.

The invention is illustrated by way of example with reference to the accompanying drawings in which Figure 1 is a perspective view of an internal vent flap of a ventilation unit according to the invention.

Figure 2 is a view of the flap of Figure 1 in the open position.

Figure 3 is a perspective view of the external louvre unit.

Figure 4 is a view of the face of the louvre unit which is adapted to lie against the window frame.

Figure 5 is a view of the face of the vent unit which is adapted to lie against the window frame.

Figure 6 is a sectional view on an enlarged scale of the vent unit along the lines X-X in Figure 1, and Figure 7 is a view of the vent unit along the same section lines but showing the vent flap in partially and fully opened position.

Referring to Figure 1, the vent flap unit consists of a moulded vent flap 1, a vent base 2 and two resilient spring members 3, 4 set into the base unit near each end.

The base unit 2 has, running along its lower outer edge, a generally circular bead 7 and the flap unit 1 has a corresponding curvature groove 8 along its base. The spring unit 4 consists of a engineering grade plastics moulding with a resilient tongue 12 having a free end 13 and a ridge 14.

The lower edge of flap member 1, denoted 16 in Figures 6 and 7, is dimensioned relative to groove 8 so that flap 1 may be resiliently inserted into the assembly of base member 2 and spring units 3 and 4 to adopt the position shown in Figure 6. In this position, the edge 16 is slightly lower than the tip 13 of the spring which is displaced, as seen in Figure 6, somewhat to the right of its unstressed position. This holds the flap member 1 firmly in the position shown in Figure 6, effectively holding flap 1 tightly against base member 2 and accordingly not letting any air pass through.

As can clearest be seen from Figure 2, base member 2 consists of an external frame having the spring members 3 and 4 received near its ends and having three bridge members 20 across it to maintain it dimensionally stable.

Moulded on to the rear of the frame are some locating pins or ribs 22 which lie against the floor and ceiling of a slot in a window frame.

The frame also has two apertures 24, one at each end, through each of which a fixing screw may pass to secure the base number 2 against the window frame or the like.

As shown in Figure 7, flap 1 may be pulled out, to assist which there is a slight depression 26 in its upper surface, to lie in the position shown in full in Figure 7. This is achieved with its lower edge 16 riding up on to the spring 3 or 4 and being held firmly in position, i.e r not loosely rattling, by the resilient force of springs 3 and 4 against the lower edge of flap 1. The travel of flap 1 is limited by the corner, denoted 28 in Figure 6, coming to lie against the corner of bead 7 denoted 30 in Figure 6.

Turning now to the louvre unit shown in Figures 3 and 4, this consists of a moulded plastics louvre unit 40 with a pair of end caps 42, configured to match the external appearance of the louvres. Each end cap is a clip fit over the end of the main moulding 40 to conceal apertures 44 through which fixing screws may pass to hold the louvre unit on the outside of the window frame.

The louvres themselves are held firmly in position by integrally moulded bars 46 which lie against the window frame while the inner edges of the individual louvres 48 are spaced therefrom.

The edge of the bottom-most louvre 48 closer to the window frame in use has depending from it a set of teeth 50 in the form of a comb, the free ends of teeth 50 being dimensioned to lie slightly away from the external surface of the window frame. This arrangement channels water drips down and ensures that water passes down the outside of the window and does not pass into the ventilation slot through the window frame and either into the window frame itself or into the interior of the building.

The main moulding 40 of the louvre unit may have locating ribs or pips analogous to configurations 22 on the vent unit in order to locate it accurately with respect to the slot in the window frame.

As shown in the drawings, the internal ventilator flap and external louvre unit are of a certain length. If appropriate, they may be shorter or longer, and if much longer may include fixing apertures intermediate the ends. The vent flap may also be replaced by two or more flaps in line, mounted on a common base member 2. Also, in place of apertures with fixing screws, the units may be attached to the frame member in other ways, e.g. by adhesion or even by interengaging clips spanning the internal and external units.

Claims (6)

1. A ventilator unit having an internal ventilator flap and an external louvre unit, each adapted for mounting on opposite sides of a frame member with an aperture on it, wherein the external louvre unit comprises a set of downwardly inclined louvres with their roomwards edges held away from the frame member and wherein, adjacent the inwards edge of the lowermost louvre member, there is provided a generally downwardly directed comb, the free ends of the teeth of which are arranged to lie adjacent but slightly spaced from the frame member.

2. A ventilator unit according to Claim 1, wherein the pitch of the louvres of the louvre set, the spacing of the teeth of the comb, and the distance the teeth ends from the frame member are all less than 2mm substantially to prevent the ingress of flying insects.

3. A ventilator unit according to Claim 1 or 2, wherein the internal flap and the louvre member are preferably constructed from plastics materials, by injection moulding.

4. A ventilator unit according to Claim 3, wherein the ventilator flap and the louvre unit have appropriate apertures for the receipt of fixing screws and locating projections adapted to locate each unit with respect to an aperture, slot through the window frame member.

5. A ventilator unit according to Claim 4, wherein the projections are positioned so that the louvres extend from slightly above the aperture or slot to a position no higher than the base of the aperture or slot, with the teeth of the downwardly directed combs lying all below the aperture or slot when the louvre unit is installed.

6. A ventilator unit substantially as hereinbefore described with reference to the accompanying drawing.