GB2126707A

GB2126707A - Louvred ventilators

Info

Publication number: GB2126707A
Application number: GB08223646A
Authority: GB
Inventors: John Benjamin Rhodes Hughes
Original assignee: GREENWOOD AIRVAC VENTILATION
Current assignee: GREENWOOD AIRVAC VENTILATION
Priority date: 1982-08-17
Filing date: 1982-08-17
Publication date: 1984-03-28
Also published as: GB2126707B

Abstract

A ventilator comprises parallel louvre blades (15) that are inclined to the vertical and a guard (28) located horizontally between adjacent blades (15), adapted to allow air to flow through them and with means (flaps 29a) to cause such air to be directed against at least one surface (e.g. the bottom of the adjacent superior blade 15). The flaps may act to force the air flow against the adjacent superior louvre blade 15 (Figure 3) or may act to force the air to follow a tortuous path through an arrangement of guards 28' (Figure 8). The guards (28) are preferably firmly connected to the blades to increase the rigidity of the structure. The guard (28) may have means (30) which wedgingly engage recesses (27) in the blades (15) or may be riveted to the blades. The blades (15) are mounted on supports (11) and the arrangement is such that either the blades or the supports are preferably under stress or tension. <IMAGE>

Description

SPECIFICATION A louvred ventilator This invention relates to louvred ventilators, in particular those ventilators used to occupy a ventilation hole in a wall.

A disadvantage found in such ventilators is that rain can be carried from the atmosphere through the ventilator into whatever space is being ventilated by the flow of air. This invention seeks to mitigate this disadvantage.

One aspect of the present invention provides a louvred ventilator comprising an array of superimposed spaced parallel and substantially horizontally extending louvre blades, the blades being inclined to the vertical, and at least one respective guard extending substantially horizontally between the louvre blades of each pair of adjacent louvre blades, the guard being provided with a plurality of apertures adapted to allow air to flow through them and with means to cause such air to be directed against at least one surface. It has been found that water droplets, dust and the like entrained in the air flow are forced out of suspension and onto the ventilator.

The upwardly flowing air may impinge on the undersurface of the upper of the said adjacent louvre blades or on a surface of the guard itself.

A second aspect of the invention provides a kit of parts comprising a plurality of louvre blades and at least one guard to be mounted substantially horizontally between two of the louvre blades, the guard being formed with a plurality of apertures adapted to allow air to flow through them and with means to cause such air to be directed against at least one surface.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described by way of example and with reference to the accompanying drawings, in which: FIGURE 1 is an end elevation of one embodiment of a ventilator in accordance with the invention; FIGURE 2 is an enlarged side elevation of part of the ventilator of Figure 1; FIGURE 3 is a fragmentary schematic perspective view of part of the ventilator of Figures 1 and 2; and FIGURES 4 to 8 are views, corresponding to that of Figure 3, showing various modifications.

Referring to Figures 1 and 2, one embodiment of a ventilator in accordance with the present invention comprises two channel members, only one of which 1, is shown, which may be extruded from aluminium or the like, the channel members being adapted to be secured to a wall with their longitudinal axes vertical, and the channels being located on either side of an aperture (not shown) left in the wall when the wall is constructed. Each channel member comprises two parallel arms and a perpendicular web. A front channel is defined between the two arms and the web. A second rear channel is formed behind the web. The web of the channel may be provided with apertures or slots adapted to receive screws to enable the channel member readily to be mounted in position.

Mounted within the front channel of each channel member 1 is a plurality of louvre support members 2. Each such louvre support member 2 may be a portion cut from an aluminium extrusion, or may be formed of any other suitable material.

Preferably the louvre support member is moulded from engineering plastics. Each louvre support member 2 comprises a vertical portion 3 so dimensioned as to be received slidably within the said front channel of the channel member 1. The said vertical portion 3 of the louvre support member 8 is provided with spigots 4 on the upright portion of this member which are utilised to secure the support member to appropriate apertures in the support channels. The spigots 4 comprise two linear portions 5, 6, each having appropriate chamfered 7 and rebated 8 surfaces, the portions being separated by an appropriate gap.It is envisaged that the spigots 4 will be pushed through appropriate apertures formed in the channel member 1 the chamfers 7 on the end faces of the spigots 4 forcing the two parts of each spigot 4 together to enable the spigot 4 to pass through the aperture. The natural resiliency of the material utilised to form the louvre blade support member 2 will then force the two halves of the spigot 4 apart so that the rebate surfaces 8 engage on the material defining the apertures, thus securing the spigots 4 in position.

In order to ensure that the louvre blade support members 2 do not become loose, for example if the material of the channel member 1 or support member 2 expands and contracts due to changes of temperature, serrated wedges 9 are provided which may be driven between the two parts of each peg to force the parts of the pegs firmly apart to ensure that the louvre blade support member is always firmly mounted in position. Each wedge 9 may be moulded of plastics material and may have serrated surfaces, although a wedge of any appropriate design may be utilised.

At its lower end the louvre support member 2 is provided with a horizontal forwardly extending arm 10 that terminates in a downwardly and forwardly deflected finger 11. At its uppermost end the support member 10 is provided with a downwardly and forwardly deflected finger 12 that is substantially parallel to the downwardly deflected finger 12 on the horizontal arm 1 1.

The louvre support members 2 are mounted in each channel member 1 in pairs, the support members 2 of each pair being located in respective channel members 1 on the same level as one another and adapted to support a respective louvre blade 15.

Each louvre blade 15 is an extrusion of aluminium or the like and is preferably of uniform cross-section throughout its length. The louvre blade comprises a planar portion 22 which is adapted to contact the downwardly deflected finger 1 1 on the horizontal arm 10. The louvre blade 15 is adapted to extend downwardly beyond the downwardly deflected finger 11 provided on the horizontal arm 10 and is also provided with an upwardly directed lip 23 at its lowermost free edge, which forms a channel to direct water running down the top of a louvre blade to one side of the ventilator. This minimises any "cascading" under severe conditions. The planar portion 22 of the louvre blade 15 extends adjacent a triangular web 24 formed by the support member 2 and a further portion 25 of the louvre blade extends upwardly immediately adjacent the vertical portion 3 of the support member 2.A spring clip or the like may be provided which is clipped or snapped onto the adjacent free end of the said downwardly deflected finger 12 and the free end of the portion 14 of the louvre adapted to lie immediately adjacent the downwardly deflected finger 12. This serves to secure the two components together.

The rear surface of each louvre blade 15 is provided with a rearwardly and upwardly extending flange 17 which defines a recess or pocket adapted to accommodate the downwardly deflected finger 1 1 provided on the horizontal arm 10. The downwardly deflected finger ills provided, on its under surface, with a substantially "V" shaped notch 16 and the adjacent portion of the flange 17 has an inwardly-directed V-shaped protrusion 1 8 of the louvre blade 1 5, the arrangement being such that, when the finger 11 is inserted into the said channel, the "V"-shaped protrusion 18 on the flange 17 will engage with the notch 16 to ensure a firm interlocking grip between the finger 11 and the louvre blade 15.

The louvre blade 1 5 and the support member 2 are preferably so dimensioned and shaped that, when the said downwardly extending finger 11 is located within the said pocket and the portion 14 of the louvre blade 1 5 engages the abutment 13, either the louvre blade 1 5 or the support member 2 or both are placed under stress or tension. This may be achieved by angling the downwardly deflected finger 11 provided at the free end of the horizontal arm 10 so that the axis of this finger 1 1 is not precisely aligned with that of the pocket defined by the flange 17. Alternatively the length of the horizontal arm 10 may be selected so that the downwardly deflected finger 11 at the end of the horizontal arm 10 is not aligned with the pocket. Furthermore, as mentioned above, the finger 12 may be placed under stress.In any event the arrangement is preferably such that one or both of the members is placed under stress or tension when the finger 12 is introduced to the pocket and this serves to ensure that a firm connection is provided.

The downwardly deflected finger 12 provided at the uppermost end of each support member is provided with a means 13 defining an abutment which engages the free edge of the immediately adjacent portion 14 of a louvre blade 15. The arrangement is such that the finger 12 with the abutment 1 3 is placed slightly under tension when the louvre blade 15 is placed in position.

The louvre support member 2 is also provided with a substantially triangular protrusion 19 formed on the lower surface thereof, one inclined face 20 of this protrusion being substantially parallel with the adjacent face 21 of the uppermost downwardly deflected finger 12 of the next adjacent louvre support member 2. Whilst the accompanying illustration shows the inclined face 20 of the protrusion 19 being separate from the face 21 of the adjacent downwardly deflected finger 12, in practice these two surfaces would substantially abut one another, thus increasing the overall rigidity of the assembly.

An upstanding flange 26 is provided on the uppermost surface of the louvre blade 1 5 in the upper region thereof and a further inwardly directed flange 27 at the base thereof, these flanges defining, with the remaining parts of the louvre, cavities which accommodate portions of a bird or vermin guard 28 as will be explained hereinafter in greater detail.

Figure 3 of the accompanying drawings is a perspective view showing the louvre blades 15 of the embodiment illustrated in Figure 1, the louvre support members and channel members being omitted for the purpose of clarity of illustration.

A respective rectangular guard 28 is so mounted in position as to extend substantially horizontally from the recess 27 at the lowermost portion of each blade 15 to the other recess 26 at the top of the next adjacent blade 1 5 in order to deny birds and/or vermin access to whatever is being ventilated. The guard 28 is formed from a substantially planar sheet of metal, the sheet being provided with regular perforations 29 formed therein.

The perforations 29 are arranged as longitudinally-spaced arrays of parallel rectangular perforations, the long dimension of each perforation 29 being aligned with the long dimension of the guard 28 and hence also with that of the adjacent louvre blade 1 5. The perforations are formed by a cutting and punching operation which creates and folds down a plurality of generally rectangular flaps 29a of the sheet to leave the perforations 29. Each flap 29a inclines to the vertical by approximately the same extent and the guard 28 is so oriented that the planes of the flaps intersect the plane of the adjacent superior louvre blade at a line above the guard 28.

This inclination of the flaps 29a towards the adjacent superior blade 15 has been found to be highly advantageous because air, as it passes through each aperture, is directed against the undersurface of the adjacent superior blade and thus entrained water droplets, dust and the like can be forced out of suspension and will coalesce on the blades 15. This is illustrated schematically in Figure 3 by arrow A. The water will flow down the undersides of the blades 1 5, into the channel defined by the flange 17, and will thus flow to the sides of the ventilator where the water can be discharged appropriately. Hence the air flowing into whatever is being ventilated has been found to be drier and cleaner with a ventilator accordance with the invention than would otherwise be the case.

The free long edges of the sheet of metal have respective downwardly depending flanges 30 and the arrangement is such that the guard 28 may be slidden into position between two louvre blades 15. The guard 28 then serves as a reinforcing member between the blades 15 since, in sliding the guard into position, the guard firmly grips the portions of the louvre defining the said recesses with the flanges 30, thus increasing the overall rigidity of the structure.

In another embodiment of the invention, the guard 28 is provided with a circular bead along one long side edge thereof and an oval bead along the other long side edge thereof, the beads being inserted in appropriate channels defined by flanges formed on a modified louvre blade.

In yet another embodiment of the invention, a modified type of guard is mounted in position between adjacent louvre blades, the guard being formed with the peripheral flanges 30 directed upwards instead of downwards. The flanges 30 are pop-riveted or otherwise secured to opposed planar surfaces of adjacent modified louvre blades.

Each louvre blade has a downwardly depending lip at the lower free edge thereof, there being an inwardly directed shelf at the lower edge of this downwardly dependent lip to support the modified guard 28. It is to be noted that in this embodiment of the invention the guard is firmly mounted in position and will thus increase the rigidity of the overall assembly.

In all the above described embodiments of the invention in which a guard is provided, the guard will be supplied in appropriate lengths. At each end of each length of the guard there may be a reinforcing rib or the like, so that each portion of the guard can be considered to be surrounded by a substantially rigid frame, although it is conceivable that at the terminal edge regions each portion of guard will have a zone which is of half the thickness of the remainder of the guard, thus permitting the zones of half thickness to be superimposed over the corresponding zones of adjacent guards, the superimposed zones being secured together for example by an adhesive or by rivets, or by any other appropriate means.

The guards 28 may be made from stainless steel, aluminium or a plastics material, or from any other convenient material.

Possible variations in the form and arrangement of the guard will now be described with reference to Figures 4 to 8 (in which, for simplicity, the same reference numerals are used as in Figures 1 to 3).

Figure 4 shows a guard 28 in which the flaps 29a extend above the general plane of the guard, instead of below, but which are inclined to that plane at the same angle as described above with reference to Figure 3. In addition, the flanges 30 are directed upwards, instead of downwards, to create gutters for water trapped on the guard.

Figure 5 illustrates a guard 28 in which the flaps 29a extend both above and below the general plane of the guard 28 and which, once again, are at the same angle to that plane as are the flaps of the embodiment of Figures 1 to 3.

Clearly, some form of welding operation will be required here in addition to the cutting and punching operation referred to above. Once again, the side flanges 30 are directed upwardly instead of downwardly.

Figure 6 shows the use of two guards 28 between the louvre 1 5 of each adjacent pair. The upper guard 28 has upwardly-directed side flanges 30, whereas the side flanges 30 of the lower guard extend generally horizontally. The flaps 29a of the upper guard are generally coplanar with those of the lower guard, as in the case of the Figure 5 embodiment.

The guard 28 of the embodiment shown in Figure 7 has upwardly-directed flaps 29a similar to those of the embodiment of Figure 4, but there are no upwardly-or-downwardly directed side flanges 30. A possible variation of this embodiment in which the side flanges 30 are omitted would be for the flaps 29a to extend downwardly instead of upwardly. The omission of the side flanges 30 gives a flat run-off of trapped water to the gutter means constituted by the flanges 26 and 27 of the adjoining louvre blades 15.

A rather more radical modification is illustrated in Figure 8. The guard comprises two parts 28', provided one on top of the other between the louvre blades 1 5 of each pair of adjacent blades, each part 28 being generally planar. The apertures 29' of the lower part are bordered by generally vertical upstanding flaps 29a' and, correspondingly, the apertures 29' of the upper part are bordered by substantially vertical downwardly-depending flaps 29a'. The free edges of the flaps 29a' of each part almost touch the planar portion of the other part. The respective series of apertures 29' of the two parts are staggered with respect to one another, and thus it will be appreciated that air flowing upwardly through the two-part guard must follow a tortuous path.The resulting sequence of changes of direction of the air flow will tend to throw entrained dust and water droplets out of suspension and onto the guard. The upstanding flaps 29a' of the lower part 28' can constitute part of a gutter means to direct the water collected in this way to, for example, a side edge of the ventilator. The long edges of one or other or both of the two parts may engage the louvre blades 1 5 in any of the ways mentioned above in order, for example, to enhance the rigidity of the ventilator.

It is to be appreciated that, whilst so far the invention has been described with reference to a completed ventilator, the invention also relates to a kit of parts forming such a ventilator. The kit of parts would comprise two channel members 1 or one channel member intended to be sawn or cut to appropriate lengths, a plurality of the louvre support members 2, a plurality of louvre blades 15 (or one member intended to be cut into lengths to form the louvre members), a plurality of the spring or snap clips, if such clips are to be utilised, and a plurality of the guards.

In assembling a ventilator from such kit of parts, initially two channel members of appropriate length will be screwed or otherwise secured to a wall on respective sides of a ventilation opening already formed in the wall, and subsequently the louvre support members 2 will be mounted in the channels and secured in the desired positions with the louvre support members 2 being located in horizontally aligned pairs, that is to say with each support member in one channel having a corresponding support member at the same level in the other channel.

The louvre blades 15 will be cut, if necessary, to have precisely the desired size, and then mounted on the louvre support members 2. The downwardly deflected fingers 11 on the support members are inserted into the pockets and, as the louvre blades 15 are moved into position, either the blade 1 5 or the louvre support member 2 or both are preferably placed under stress or tension, thus ensuring that the louvres are preferably placed under stress or tension, thus ensuring that the louvres are firmly mounted in position and minimising or obviating any rattles. The spring clips or snap clips are also placed in position, if used, and the guards will be mounted in position.

It will be appreciated that a kit of parts as above described may be utilised in forming a ventilator having virtually any desired size.

If a ventilator in accordance with the invention is to be mounted over a wide aperture or over a series of adjacent apertures, three or more vertical support channels may be provided, each louvre blade being mounted on a louvre support member provided in each channel. The central channel or channels may extend across the aperture, merely being fixed to the wall above and below the aperture.

From the above description it will be appreciated that the present invention provides a kit of parts which can be readily utilised to construct a ventilator, the kit of parts comprising the channels, the louvre blade support members, the louvre blades and the guards. It is to be appreciated that the kit of parts may be provided in a completely dis-assembled condition although, in certain circumstances, it may be preferable to provide a kit of parts comprising the channel members and louvre blade support members already integrally connected together, the assembly (comprising the channels and the louvre blade support members) being secured in position and the louvre blades and guards finally being mounted in position.

Louvre ventilators in accordance with the present invention may be utilised not only to cover apertures in walls, but also to form a ventilator turret.

Claims

1. A louvred ventilator comprising an array of superimposed spaced parallel and substantially horizontally extending louvre blades, the blades being inclined to the vertical, and at least one respective guard extending substantially horizontally between the louvre blades of each pair of adjacent louvre blades, the guard being provided with a plurality of apertures adapted to allow air to flow through them and with means to cause such air to be directed against at least one surface.

2. A ventilator according to claim 1 wherein the said surface is the lower surface of the upper of the said adjacent louvre blades.

3. A ventilator according to claim 2 wherein each of the said apertures is associated with a respective flap inclined from the vertical towards the said upper blade.

4. A ventilator according to claim 3 wherein the guard is generally planar and the said flap extends above the plane of the guard.

5. A ventilator according to claim 3 wherein the guard is generally planar and the said flap extends below the plane of the guard.

6. A ventilator according to claim 3 wherein the guard is generally planar and the said flap extends above and below the plane of the guard.

7. A ventilator according to claim 3 wherein two said guards are located one directly on top of the other between the said adjacent louvre blades, the said flaps of the upper guard being upwardlydirected and the said flaps of the lower guard being downwardly-directed.

8. A ventilator according to claim 7 wherein each said flap of the upper guard is aligned with and substantially co-planar with a respective flap of the lower guard and the apertures of the upper guard are substantially aligned with the apertures of the lower guard.

9. A ventilator according to any one of claims 3 to 8 wherein each guard is formed from a sheet of metal, the apertures and flaps being formed at least partially by a cutting and punching operation.

10. A ventilator according to any one of the preceding claims wherein each edge of each guard which engages a blade is provided with a respective flange adapted to engage a recess in the blade engaged by that edge of the guard.

11. A ventilator according to claim 10 wherein each said flange is upwardly-directed.

12. A ventilator according to claim 10 wherein each said flange is downwardly-directed.

13. A ventilator according to claim 1 wherein the said surface is part of the said guard.

14. A ventilator according to claim 13 wherein the guard comprises two parts, each part being provided with the said apertures the apertures of each part being out of alignment with the apertures of the other part to force the said air to follow a non-linear path through the arrangement of guards.

1 5. A ventilator according to claim 14 wherein each aperture of each part is associated with one or more flaps so located and orientated as to increase the tortuousness of the said path followed by the air flow.

16. A ventilator according to claim 15 wherein the flaps of the upper part extend downwardly to a level adjacent, but spaced from, the lower part and the flaps of the lower part extend upwardly to a level adjacent, but spaced from, the upper part.

17. A ventilator according to claim 15 or 16 wherein the flaps of the lower part constitute part of a plurality of gutter means adapted to channel water trapped by the arrangement of part in a desired direction.

18. A ventilator according to any one of claims 1 to 17 wherein each edge of each guard which engages a blade is provided with a respective bead adapted to engage a corresponding recess in the blade engaged by that edge of the guard.

19. A ventilator according to any one of claims 1 to 17 wherein each guard is riveted to the louvre blades adjacent to it.

20. A ventilator according to any one of the preceding claims wherein the engagement of the guards and blades is such that stress or tension is applied to the blades and/or to the guards to ensure a firm joint.

21. A ventilator according to any one of the preceding claims wherein the louvre blades are so supported by two louvre support members that at least one of the louvre support members or the blades is under stress or tension to ensure a firm joint.

22. A kit of parts for forming a ventilator according to any one of claims 1 to 21, the kit of parts comprising a plurality of louvre blades and at least one guard to be mounted substantially horizontally between two of the louvre blades, the guard being formed with a plurality of apertures adapted to allow air to flow through them and with means to cause such air to be directed substantially perpendicularly against at least one surface.

22. A kit of parts for forming a ventilator according to any one of claims 1 to 21 , the kit of parts comprising a plurality of louvre blades and at least one guard to be mounted substantially horizontally between two of the louvre blades, the guard being formed with a plurality of apertures adapted to allow air to flow through them and with means to cause such air to be directed against at least one surface.

23. A ventilator substantially as described herein with reference to, and as shown in, Figures 1 to 3 of the accompanying drawings.

24. A ventilator substantially as described herein with reference to, and as shown in, Figures 1, 2 and 3 as modified by Figure 4 of the accompanying drawings.

25. A ventilator substantially as described herein with reference to, and as shown in, Figures 1,2 and 3 as modified by Figure 5 of the accompanying drawings.

26. A ventilator substantially as described herein with reference to, and as shown in, Figures 1, 2 and 3 as modified by Figure 6 of the accompanying drawings.

27. A ventilator substantially as described herein with reference to, and as shown in, Figures 1, 2 and 3 as modified by Figure 7 of the accompanying drawings.

28. A ventilator substantially as described herein with reference to, and as shown in, Figures 1,2 and 3 as modified-by Figure 8 of the accompanying drawings.

29. A kit of parts for forming a ventilator substantially as described herein with reference to, and as shown in, Figures 1 to 3 of the accompanying drawings.

30. A kit of parts for forming a ventilator substantially as described herein with reference to, and as shown in, Figures 1 to 3 as modified by Figure 4 of the accompanying drawings.

31. A kit of parts for forming a ventilator substantially as described herein with reference to, and as shown in, Figures 1 to 3 as modified by Figure 5 of the accompanying drawings.

32. A kit of parts for forming a ventilator substantially as described herein with reference to, and as shown in, Figures 1 to 3 as modified by Figure 6 of the accompanying drawings.

33. A kit of parts for forming a ventilator substantially as described herein with reference to, and as shown in, Figures 1 to 3 as modified by Figure 7 of the accompanying drawings.

34. A kit of parts for forming a ventilator substantially as described herein with reference to, and as shown in, Figures 1 to 3 as modified by Figure 8 of the accompanying drawings.

35. Any novel feature or combination of features disclosed herein.

New claims or amendments to claims filed on 25 Oct. 83.

Superseded claims 1; 22.

New or amended claims:~

1. A louvred ventilator comprising an array of superimposed spaced parallel and substantially horizontally extending louvre blades, the blades being inclined to the vertical, and at least one respective guard extending substantially horizontally between the louvre blades of each pair of adjacent louvre blades, the guard geing provided with a plurality of apertures adapted to allow air to flow through them and with means to cause such air to be directed substantially perpendicularly against at least one surface.