GB2311848A

GB2311848A - Slot ventilator

Info

Publication number: GB2311848A
Application number: GB9607125A
Authority: GB
Inventors: John Neil Anderson
Original assignee: Titon Hardware Ltd
Current assignee: Titon Hardware Ltd
Priority date: 1996-04-04
Filing date: 1996-04-04
Publication date: 1997-10-08
Anticipated expiration: 2016-04-04
Also published as: GB2311848B; GB9607125D0

Abstract

A slot ventilator (10) adapted to be mounted in a building element (21) includes a front facing strip (12) which is linked by links (14) to support elements (16). The ends of the facing strip (12) are independently moveable towards and away from the building element (21) by the manipulation of snibs (50) on the ends of the strip. Ball and socket joints (30) define a hinge axis about which the facing strip (12) is rotatable about a longitudinal axis. Each link (14) comprises a pair of resilient legs having oppositely projecting pegs (34). Each support element (16) includes a receiver for the legs. The opposed faces (40) of each receiver include a series of slots (42) which engage the pegs (34). By pushing or pulling the snib (50) at one end of the strip (12), it is possible to move the pegs from one slot to another. Alternatively, each link may be in the form of a rod extending rearwardly of a rib on the rear face of the strip, each rod including a series of spaced ball elements.

Description

SLOT VENTILATOR The present invention relates to a slot ventilator, for example for use in a room with a sealed window or a window with double or single glazing or a door wherein it is desirable to providing ventilation without having to open the window.

W095/09333 discloses a slot ventilator comprising an elongate front facing strip and support means adapted to secure the front facing strip at an entrance to an elongate ventilation slot formed through a building element, the support means including a linkage which includes a hinge for permitting rotation of the facing strip about a hinge axis substantially parallel to the longitudinal axis thereof.

This arrangement is versatile in that the facing strip may be pivoted about the hinge axis in order to direct ventilation passing through the slot ventilator in a preferred direction.

One object of the present invention is to provide a ventilator which provides versatile ventilation control, and another object is to provide a simple method of manufacturing a slot ventilator.

According to a first aspect of the present invention there is provided a slot ventilator comprising an elongate front facing strip and support means adapted to secure the front facing strip at an entrance to an elongate ventilation slot formed through a building element, the support means including a linkage which includes a hinge for permitting rotation of the facing strip about a hinge axis substantially parallel to a longitudinal direction thereof, and wherein the linkage is adapted to permit one end of the front facing strip, once the ventilator is mounted on a building element, to move forward and backward relative to the building element independently from the other end of the front facing strip.

This arrangement is highly advantageous. Once the ventilator has been installed, it is possible not only to rotate the facing strip about the hinge axis to direct ventilation passing through the ventilation slot in a preferred direction, but it is also possible to move one end of the ventilator further forward from the building element than the other end when it is desired to encourage more ventilation to pass through one end of the ventilation slot than the other. Therefore, the ventilator is highly versatile.

The linkage may include first and second linkage units spaced from one another along the length of the facing strip, each linkage unit connecting the facing strip to a support element of the support means. In some embodiments, more than two said linkage units may be employed. Preferably, the support means includes two separate said support elements, the support elements being adapted for securement at opposite ends of a ventilation slot through a building element. In this case, the facing strip may be adapted to seal against a surface surrounding the ventilation slot in a closed position of the facing strip, with one or both ends of the facing strip being moveable away from the surrounding surface to increase ventilation, as desired. Preferably, each support element includes a fixing flange which is adapted to abut against the surrounding surface of the ventilation slot, and each flange may include one or more apertures for securing the support element to the building element, such as with screws.

Alternatively, the support means may comprise a slotted backing member of the ventilator against which the facing strip is adapted to seal in a closed position thereof, the linkage units being connected to the backing member at locations spaced from each other along the facing strip. In this case, the ends of the facing strip are independently moveable forward from the slotted backing member to increase ventilation as desired.

Preferably, each linkage unit includes a link element extending rearwardly from the facing strip, the link element having a rear portion which slidably engages a receiver of the support member and a front portion which is connected to the front facing strip, for permitting slidable forward and backward movement of the facing strip.

Preferably, one of the receiver and the rear portion of the link element includes a projection or recess which is selectively engageable with a series of recesses or projections in the other of the receiver and the link element, the series of recesses or projections being located at different distances behind the facing strip.

This is highly advantageous, since the facing strip may be positioned in various open positions, indexed at different distances in front of the support element.

Preferably, the projections and recesses are resiliently engageable.

The receiver may comprise a channel and the link element may include a rod which includes a pair of substantially parallel legs having opposed projections thereon, both legs being received inside the channel of the support element, the channel having opposed faces, the series comprising a series of pairs of recesses located in opposing surfaces of the channel at different positions along the channel. This is a particularly convenient way to provide indexed open positions of the facing strip.

Preferably, each linkage unit includes a ball and socket joint, the positions of the ball and socket joints of the first and second linkage units together defining the hinge axis. Preferably, the ball of each ball and socket joint is slidable in its socket along the longitudinal direction of the facing strip, the socket preferably including elongate slots formed, generally aligned with the longitudinal direction of the facing strip, in opposed faces thereof with the ball being slidable along the slots. This arrangement insures that when one end of the facing strip is moved further forward than the other end, the ball and socket joints accommodate the decreasing apparent length of the facing strip relative to the support means which may be fixed to a building element.

When one of the linkage units includes a ball and socket joint, this may be located at a side of the link element which is adjacent a rear face of the facing strip. Alternatively, when one of the linkage units includes a ball and socket joint, this may be located on a rear portion of the link element, spaced from a rear face of the facing strip.

In the later case, part of the link element may form part of an elongate rib running along the length of the rear face of the ventilator and extending rearwardly from the rear face, the ball and socket joint being connected to a rear edge of the rib. The ball of the ball and socket joint may be formed on the rear edge of the rib, and the facing strip, rib and ball may be integrally formed.

In one embodiment, the ball of the ball and socket joint is formed on the rear edge of the rib and the receiver of the support element comprises a channel, the ball being received inside the channel, the channel including a series of pairs of recesses located in opposite surfaces of the channel at positions spaced from each other in the rearward direction. In this case, the ball may be located in a selected pair of the recesses to position the facing strip a selected indexed distance forward of the support element.

In embodiments where a said receiver is provided with a said channel, the channel may include further opposed faces which are at a slant to one another, the opposed faces and further opposed faces defining a boxlike container with a receiving opening adjacent the facing strip, the retainer narrowing, in the longitudinal direction of the facing strip, with increasing distance from the front facing strip. In this case, the recesses may comprise elongate slots aligned generally with the longitudinal direction of the facing strip. The slots may advantageously allow the channels of support elements fixed to a building structure to accommodate apparent increases or decreases in length of the facing strip between the support elements as the ends of the facing strip are moved forward and backward. The box-like retainer advantageously provides firm support for the facing strip. The relatively wide opening to the retainer resulting from the further opposed faces at a slant to one another advantageously prevents the linkage from jamming, particularly when the linkage includes a rod slidably extending into the channel.

When the channel incorporates a series of elongate slots aligned generally with the longitudinal direction of the facing strip, these slots may be arranged to be shorter in length with increasing distance from the facing strip.

When each linkage unit includes a receiver and link element with at least one interengageable projection and recess thereon, a series of projections may be provided on one of the receiver and the link member, preferably on the link member, the projections comprising a plurality of ball elements spaced from one another along a rod extending rearwardly from the facing strip, and the receiver may comprise a socket in the support element of the support means, each of the ball elements being selectively movable to engage the socket to form a ball and socket joint, with a part of facing strip adjacent the ball and socket joint being located a corresponding distance in front of the joint. Advantageously, ball and socket joints once so formed in the two linkage units may define the hinge axis of the facing strip. In this case, the rod may extend rearwardly from the rear edge of an elongate rib which is located on a rear face of the front facing strip.

Preferably, at least one of the linkage units includes an end stop for limiting forward movement of the facing strip relative to the support element.

Preferably, the front facing strip is flat and an operating member for positioning the facing strip comprises an integral extension of one end of the facing strip, angled at a slant to the facing strip.

Preferably, each end of the ventilator includes a said operating member.

According to a second aspect of the present invention there is provided a method of manufacturing a slot ventilator which comprises moulding a closure member of the ventilator in a first mould, forming a support element for the closure member, preferably by moulding in a second mould, and connecting the closure member and support element together with one of the closure member and the support element having a series of ball elements or sockets located at different distances from a front facing strip of the closure member, and the other of the closure member and the support element having a socket or ball element adapted selectively to engage the ball elements or sockets. The method may include moulding in the first mould an elongate rib extending along a rear face of the front facing strip. The method may include moulding an end stop in the first mould to restrict forward movement of the closure member relative to the support element, once the closure member and support element are connected together. Preferably one or both of the closure member and support element are moulded of resilient plastics material. This method of manufacturing a slot ventilator is advantageous in that, when all of the parts are moulded, very few mould patterns are needed to produce a relatively versatile ventilator.

The present invention may be carried out in various ways and various embodiments of preferred slot ventilators in accordance with the invention will now be described by way of example with reference to the accompanying drawings in which: Fig. 1A is a schematic part sectional side view of a preferred embodiment of a slot ventilator in accordance with the present invention; Fig. 1B is a schematic sectional view on the line A A' in Fig. lA; Fig. 2 is a schematic part sectional end view of another preferred embodiment of the slot ventilator in accordance with the invention; Fig. 3 is a schematic exploded view of part of the ventilator of Fig. 2; Fig. 4 is a schematic part sectional side view of another preferred embodiment of a slot ventilator in accordance with the present invention; Fig. 5 is a schematic part sectional end view of a ventilator of Fig. 4; Fig. 6 is a schematic exploded part view of the ventilator of Figs. 4 and 5; Fig. 7 is a schematic part sectional side view of another preferred embodiment of a slot ventilator in accordance with the present invention; Fig. 8 is a schematic part sectional end view of the ventilator of Fig. 7; Fig. 9 is an exploded view of part of the ventilator shown in Fig. 7 and 8; Fig. 10 is a schematic part sectional side view of another preferred embodiment of a ventilator in accordance with the present invention; Fig. 11 is a schematic part sectional end view of the ventilator shown in Fig. 10; and Fig. 12 is an exploded view of part of the ventilator of Figs. 10 and 11.

Referring to Fig. 1A, a preferred embodiment of a slot ventilator 10 in accordance with the present invention comprises a substantially flat front facing strip 12, linked by a pair of links 14 to a pair of support elements 16 which are mounted by fasteners such as screws (not shown) passing through apertures 18 through mounting flanges 20 into a building element 21.

The links 14 each have a ball element 22 located at the head end 24 thereof. The ball elements engage resiliently in sockets 26 located at each end of a rear face 28 of the front facing strip 12. The ball elements 22 and sockets 26 thus form ball and socket joints 30.

The resilient engagement between the ball elements 22 and sockets 26 may be accomplished in various ways, such as by making one or more of those parts from a resilient material and, additionally or alternatively, each ball element may comprise a plurality of portions each including a part spherical outer surface and these parts being biased outwardly away from each other towards the surrounding surfaces of the socket 26.

The ventilator shown in Figs. 2 and 3 has an identical facing strip 12 to that shown in Fig. 1 and identical links 14, but slightly different support elements 116.

As Fig. 3 shows, the link 14 of both ventilators includes a pair of resilient legs 32 having oppositely projecting pegs 34.

The support elements 16, 116 of the ventilators of Figs. 1A and 1B, and Figs. 2 and 3 have downwardly extending flanges 36 on which are formed receivers 38 for the legs 32 of the links 14. Each receiver includes a pair of opposed faces 40, the opposed faces including corresponding series of elongate slots 42 formed therethrough. An adjacent surface 44 of the flange 36 is opposed by a further opposing surface 46 which is at a slant thereto. The three slots become progressively longer towards the side of the flange 36 which is adjacent the mounting flange 20 which contains the aperture 18 therein.

It will be appreciated that the only difference between the ventilator shown in Figs. 1A and 1B on the one hand and the ventilator shown in Figs. 2 and 3 on the other is that the box-like retainer 48 formed by the opposed faces 40 and the faces 44 and 46 at slant to one another, in the ventilator of Fig. 1A and 1B, is recessed to the rear of the mounting flange 20. The purpose of this recessing will be explained below.

The pegs 34 of the links 14 are adapted to resiliently engage in the slots 42 of the retainer 48, but by pulling or pushing an operating snib 50 at an end of the facing strip 12 adjacent the link, 14 it is possible to disengage the pegs 34 from a particular opposed pair of the slots 42 and to reengage the pegs 34 with a different opposed pair of the slots 42 spaced a different distance behind the flange 20. Thus, it is possible, by pulling or pushing on the operating snibs, independently to set the position which each end of the facing strip 12 takes up in front of its respective support element 16. Thus, it is possible to provide more ventilation at one end of the ventilator than the other, if that is desired.

With the facing strip 12 spaced in front of the support elements 20, the ball and socket joints 30 together define a hinge axis parallel to the particular longitudinal direction taken up by the facing strip 12 in that position, about which the facing strip may be rotated, by appropriate manipulation of one or both of the operating snibs 50. Thus, it is also possible to vary the amount of ventilation, in an application where the facing strip is mounted adjacent, say, a horizontal ventilation slot, passing above and below the facing strip.

This can be easily understood referring to Fig. 1B which shows the ventilator 10 mounted adjacent a ventilation slot 52 passing through the building element 21 which comprises the frame of a window assembly 54, the window assembly also including a window sash 56 sealed to the frame by a seal 58.

The ventilator 10 is shown in a closed position thereof sealed by optional gaskets 60, such as of soft sealing material to the inner side 62 of the window frame 21. The outer side 64 of the ventilation slot is protected by a weather hood 66 of known construction. It will be appreciated that either end of the facing strip may be pulled forward in the direction B shown in Fig. 1B to an open position spaced in front of the support element 16 and in which the gaskets 60 at that end of the facing strip no longer seal against the building element 21, the facing strip therefore permitting ventilation to pass through the slot 52. Once the facing strip has both ends located in a forward position, with the links 14 of the pegs located in either the middle pair of the slots 42 or the forward pair of the slots 42 (as opposed to the rear pair of these slots 42 corresponding to the closed position of Fig. 1B) it is then possible to rotate the facing strip 12 about the hinge formed by the ball joints 30 to provide more or less ventilation above a top edge 68 of the facing strip than below a bottom edge 70 thereof.

The elongate nature of the slots 42 ensures that the retainers 48 and links 14 are capable of accommodating the increasing or decreasing apparent length of the facing strip along a line joining the two support elements 16, as one end of the facing strip is moved further from or closer to the support elements 16 than the other. In addition, the further opposed face 46 of the retainer 48 which is at a slant to the downwardly extending flange 36 ensures that the links 14 are capable of leaning during this accommodation, so that the links 14 do not jam against the retainers 48. The left hand link 14 in Fig. 1A is shown to be leaning and is comfortably accommodated between the flange 36 and slanted face 46.

The recessed nature of the retainer 48 relative to the mounting flange 20, in the ventilator of Figs. 1A and 1B, ensures that the sockets 26 are sufficiently retractable in the rearward direction shown as C in Fig. 1A to enable the gaskets 60 to seal against the inner side of the window frame 21.

The non-recessed nature of the retainers 48 of the support elements 116 shown in Figs. 2 and 3 ensures that the facing strip cannot be pushed in the rearward direction far enough to seal against the window frame.

Thus the ventilator of Figs. 2 and 3 allows ventilation even in the minimum ventilation position of the facing strip 12 as may be required by, for example building regulations or other circumstances.

The ventilator 10 shown in Figs. 10, 11 and 12 is similar to the ventilator shown in Figs. 1A and 1B and similar reference numerals are used to denote similar components.

The ventilator shown in Fig. 10 includes substantially different links 214, sockets 226 and support elements 216 to those of the ventilator of Figs. lA and 1B.

The links 214 each have a ball element 222 at a head end 224 thereof and resilient legs 232 at an opposite end thereof. The resilient legs include oppositely projecting pegs 234 at different distances along the length of the link 214.

The legs 232 of the link 214 are slidably receivable within a square bore 270 of the support element 216. The square bore 270 includes a pair of slots 272 located in opposite faces thereof. One of these slots 272 is shown in Fig. 12. The links 214 are linearly slidable in the bores 270 and the resilience of the legs 232, and optionally also the relative softness of the material of either the pegs 214 and the slots 272, permits the pegs 234 to enter the slots 272 when adjacent the slots, to hold the links 214 in selective indexed positions relative to the support elements 216.

The sockets 226 each include pairs of elongate opposed slots 274 which are resiliently engaged by the ball elements. The elongate nature of the slots 274 permits the sockets 226 and therefore the facing strip 12 to move along the longitudinal direction of the facing strip with respect to the links. Since the links are linearly slidable in the bores 270, the elongate slots 274 are employed to ensure that the ball and socket joints 230 formed by the links 214 and sockets 226 accommodate any apparent increase or decrease in the length of the facing strip along a line joining the two support elements 216, as one end of the facing strip is moved further from or closer to the building element 21 than the other end of the facing strip 12.

A front face 276 of each of the support elements 216 adjacent one of the sockets 226 is recessed with respect to a mounting flange 220 of the support element 216 and this permits the facing strip 12 to move rearwardly to a fully closed position, like the position shown in Fig. 1B, in which longitudinal gaskets (not shown) on the facing strip 12 of the Fig. 10 ventilator engage surfaces of the building element 21.

The series of pegs 234 of each link 214 ensure that each end 217 of the facing strip 12 may be positioned in a series of indexed positions at different distances from the support element 216, independently of the position of the opposite end of the facing strip 12. The ball and socket joints 230 permit the facing strip 12 to rotate about a hinge axis defined by the two ball and socket joints 230 once both ends of the facing strip are in a forward position.

The ventilator 300 of Figs. 4, 5 and 6 includes a substantially flat facing strip 302 with operating snibs 304 at each end thereof, and a longitudinal rib 306 extending along a rear face 308 thereof.

Ball elements 310 are located at either end of a longitudinal rib 306.

Each ball element 310 is adapted to engage a receiver 312 of a support element 314, and the ball elements 310 are spaced by the rib 306 from the rear surface 308 of the facing strip 302.

The receiver 312 includes a pair of opposed faces 316 in which are formed series of opposing elongated slots 318. The slots are elongate in the general direction of the length of the facing strip 302.

The ball elements 310 are selectively indexably engageable between opposed pairs of the slots 318. A force applied on one of the operating snibs 304 in the direction D will, once large enough cause the adjacent ball element to disengage from the front or middle of the three pairs of slots 318 shown and the ball element will, on continued rearward movement, engage between the next most rearward pair of slots 318.

Likewise the ball elements may be indexed forward in their respective receivers 312 by applying a forward force in the direction opposite to direction D shown in Fig. 4. However, end stops 320 are provided at each end of the rib 306, adjacent the ball elements 310, with engagement flanges 322 located behind the receivers 312, so that once each ball element is located between the front pair of slots 318, it can move no further forward.

The end stops 320 advantageously prevent the facing strip 302 from being disconnected inadvertently from the support elements 314.

The ball elements 310 and receivers 312, it will be appreciated, permit independent movement of the ends of the front facing strip 302 forward and backward relative to the support elements 314. In addition, the ball elements, being positioned behind the rear face 308 of the front facing strip 302 permit hinging of the front facing strip 302, when in a forward open position, about a hinge axis passing through the two ball elements 310.

The longitudinal nature of the slots 318 ensures that the apparent lengthening or shortening of the facing strip 302 along a line between the two support elements 314 is accommodated as one end of the facing strip 302 is moved further from or closer to the building element 21 than the other end of the facing strip 302.

In the embodiment of Figs. 4, 5 and 6, the facing strip 302, operating snibs 304, ball elements 310, and end stops 320 may all be moulded integrally with one another from material such as plastics. The ventilator is thus inexpensive to produce.

The ventilator 400 shown in Figs. 7, 8 and 9 includes a substantially flat front facing strip 402 with operating snibs 404 located at each end thereof.

A longitudinal rib 406 extends along a rear face 408 of the front facing strip 402 and at each end of the longitudinal rib is located a linkage rod 410. Each linkage rod 410 extends rearwardly from a rear edge 412 of the rib 406, and the linkage rod includes a series of ball elements 416 at spaced locations therealong.

Each linkage rod 410 is slidably engageable in a receiver portion 418 of a support element 420. The support elements 420 are adapted to be secured at opposite ends of a ventilation slot 422 formed through a building element 21 such as the window frame shown in Fig. 1B.

Each receiver portion 418 includes a pair of opposed side walls 424, these side walls including opposed elongate slots 426.

Each ball element is adapted resiliently to engage between the two slots 426 to hold the facing strip 402 in position, once set by manipulation of the operating snibs 404.

Fig. 8 shows the middle one of three ball elements 416 engaged between the slots 426. The resilience of the engagement between the ball element 416 and the socket 428 defined by the slots is such that pushing of the operating snibs 404 towards the support element 420 will disengage the ball element 416 from the socket 428, and continued movement of the adjacent end of the facing strip 402 towards the support element 420 will result in the upper of the three ball elements 416 shown in Fig. 8 engaging in the socket 428 to secure the adjacent end of the facing strip 402 in a closed position.

Likewise, pulling of the operating snibs 404 away from the support element 420 will cause the middle ball element 416 to disengage from the socket 428, with continued movement of the adjacent end of the facing strip 402 away from the support element 420 resulting in the rearmost of the three ball elements 416 engaging in the socket 428. However, the link rod 410 incorporates a T-bar 430 on a rear end 432 thereof. The T-bar 430 is not capable of passing between the side walls 424 and, accordingly, serves as an end stop to prevent the facing strip 402 from inadvertently being disengaged from the support element 420.

It will thus be appreciated that the two ends of the facing strip 402 may independently be moved towards and away from their respective support elements 420. The elongate slots 426 accommodate the apparent lengthening or shortening of the facing strip 402 as one end of the facing strip 402 is moved further from or closer to the building element 21 than the other.

The facing strip 402, snibs 404, rib 406 and linkage rods 410 may all be integrally formed, such as in a mould, out of plastics material. This ventilator 400 is therefore inexpensive to produce.

While the various embodiments shown in the drawings incorporate two support elements one at each end of the ventilator, the facing strip of any of these ventilators could be supported by a support means which incorporates support portions or elements at each end of the ventilator which are connected to each other. In this case the support portions or elements could be integrally formed with each other. For example, the support means may comprise a slotted backing member which is adapted to be located adjacent an entrance to a ventilation slot through a building element. The backing member may include a slot therethrough and the facing strip of the ventilator may be adapted to seal against the slot in a closed position thereof, and to move forward from the backing member to increase ventilation. Furthermore, the facing strip may in some embodiments be supported by links connected to intermediate support elements of multiple-part supports, with the intermediate support elements being connected to further support parts which are adapted to be secured to a building element.

While the embodiments described above include pairs of slots on support members, for engaging pegs or ball elements, in other embodiments, ventilators may be provided with slots engaging only one side of a ball element or an element including a peg such as a link element, and these arrangements may conveniently provide the facing strip with the same level of versatility as the various embodiments which have been described above.

While the embodiments described above incorporate two linkage units, one adjacent each end of the facing strip, it is foreseen that intermediate linkage units may be employed in other embodiments, particularly where the facing strip is relatively long.

Various other modifications may be made which will easily occur to skilled persons in the art without departing from the scope of the invention which is defined in the accompanying claims.

Claims

1. A slot ventilator comprising a elongate front facing strip and support means adapted to secure the front facing strip at an entrance to an elongate ventilation slot formed through a building element, the support means including a linkage which includes a hinge for permitting rotation of the facing strip about a hinge axis substantially parallel to a longitudinal direction thereof, and wherein the linkage is adapted to permit one end of the front facing strip, once the ventilator is mounted on a building element, to move forward and backward relative to the building element independently from the other end of the front facing strip.

2. A ventilator as claimed in Claim 1 in which the linkage includes first and second linkage units spaced from one another along the length of the facing strip, each linkage unit connecting the facing strip to a support element of the support means.

3. A ventilator as claimed in Claim 2 in which each linkage unit includes a link element extending rearwardly from the front facing strip, a rear portion of the link element slidably engaging a receiver of the support member, and a front portion of the link element being connected to the front facing strip, for permitting slidable forward and backward movement of the facing strip.

4. A ventilator as claimed in Claim 3 in which one of the receiver and the link element rear portion includes a projection or recess which is selectively engageable with a series of recesses or projections in the other of the receiver and the link element, the series of recesses or projections being located at different distances behind the facing strip.

5. A ventilator as claimed in Claim 4 in which the projections and recesses are resiliently engageable.

6. A ventilator as claimed in Claim 4 or Claim 5 in which the receiver comprises a channel and the link element includes a rod, the rod including a pair of substantially parallel legs having opposed projections thereon, both legs being received inside the channel of the support element, the channel having opposed faces, the series comprising a series of pairs of recesses located in opposing surfaces of the channel at different positions along the channel.

7. A ventilator as claimed in any one of Claims 2 to 6 in which each linkage unit includes a ball and socket joint, the position of the ball and socket joints of the first and second linkage units together defining the hinge axis.

8. A ventilator as claimed in Claim 7 in which the ball of each ball and socket joint is slidable in its socket along the longitudinal direction of the facing strip, the socket including elongate slots formed, generally aligned with the longitudinal direction of the facing strip, in opposed faces thereof with the ball being slidable along the slots.

9. A ventilator as claimed in Claim 7 or Claim 8 when dependent upon Claim 3 in which the ball and socket joint is located at a side of the link element which is adjacent a rear face of the facing strip.

10. A ventilator as claimed in Claim 7 or Claim 8 when dependent on Claim 3 in which the ball and socket joint is located on the rear portion of the link element, spaced from a rear face of the facing strip.

11. A ventilator as claimed in Claim 10 in which part of the link element forms part of an elongate rib running along the length of the rear face of the ventilator and extending rearwardly from the rear face, the ball and socket joint being connected to a rear edge of the rib.

12. A ventilator as claimed in Claim 11 in which the ball of the ball and socket joint is formed on the rear edge of the rib, and the facing strip, rib and ball are integrally formed.

13. A ventilator as claimed in Claim 10 or Claim 11 or Claim 12 in which the ball of the ball and socket joint is formed on the rear edge of the rib and the receiver of the support element comprises a channel, the ball being received inside the channel, the channel including a series of pairs of recesses located in opposing surfaces of the channel at positions spaced from each other in the rearward direction.

14. A ventilator as claimed in Claim 6, any preceding claim dependent upon Claim 6, or Claim 13 in which the channel includes further opposed faces which are at a slant to one another, the opposed faces and the further opposed faces defining a box-like retainer with a receiving opening adjacent the facing strip, the retainer narrowing, in the longitudinal direction of the facing strip, with increasing distance from the front facing strip.

15. A ventilator as claimed in Claim 6 or Claim 7, or any preceding claim which is dependent on either of these claims, in which the recesses comprise elongate slots aligned generally with the longitudinal direction of the facing strip.

16. A ventilator as claimed in Claim 15 in which the slots are shorter in length with increasing distance from the facing strip.

17. A ventilator as claimed in Claim 4 or Claim 5 in which the projections comprise a plurality of ball elements spaced from one another along a rod extending rearwardly from the facing strip, the receiver comprising a socket in the support element of the support means, each of the ball elements being selectively movable to engage the socket to form a ball and socket joint.

18. A ventilator as claimed in Claim 17 in which the rod extends rearwardly from a rear edge of an elongate rib which is located on a rear face of the front facing strip.

19. A ventilator as claimed in any one of the Claims 2 to 18 in which at least one of the linkage units includes an end stop for limiting forward movement of the facing strip relative to a said support element.

20. A ventilator as claimed in any one of Claims 2 to 19 in which the support means includes two separate said support elements, the support elements being adapted for securement at opposite ends of a ventilation slot through a building element.

21. A ventilator as claimed in any proceeding claim in which the facing strip is substantially flat and an operating snib for positioning the facing strip comprises an integral extension of one end of the facing strip angled at a slant to the facing strip.

22. A slot ventilator substantially as described herein with reference to Figs. 1A and 1B, Figs. 2 and 3, Figs. 4, 5 and 6, Figs. 7, 8 and 9, or Figs. 10, 11 and 12 of the accompanying drawings.

23. A method of manufacturing a slot ventilator which comprises moulding a closure member of the ventilator in a first mould, moulding a support element for the closure member in a second mould, and connecting the closure member and support element together with one of the closure member and support element having a series of ball elements or sockets located at different distances from a front facing strip of the closure member, and the other of the closure member and the support element having a socket or ball element adapted selectively to engage the said ball elements or sockets.

24. A method of manufacturing a slot ventilator substantially as described herein with reference to Figs. 4, 5 and 6, or Figs. 7, 8 and 9 of the accompanying drawings.

Amendments to the claims have been filed as follows 1. A method of manufacturing a slot ventilator which comprises moulding a closure member of the ventilator in a first mould, moulding a support element for the closure member in a second mould, and connecting the closure member and support element together with one of the closure member and support element having a series of ball elements or sockets located at different distances from a front facing strip of the closure member, and the other of the closure member and the support element having a socket or ball element adapted selectively to engage the said ball elements or sockets.

2. A method as claimed in claim 1 which includes moulding in the first mould an elongate rib extending along a rear face of the front facing strip.

3. A method as claimed in claim 1 or claim 2 which includes moulding an end stop in the first mould to restrict forward movement of the closure member relative to the support element, once the closure member and support element are connected together.

4. A method as claimed in any preceding claim in which one or both of the closure member and support element are moulded of resilient plastics material.

5. A method of manufacturing a slot ventilator substantially as described herein with reference to Figs. 4, 5 and 6, or Figs. 7, 8 and 9 of the accompanying drawings.

6. A slot ventilator comprising a elongate front facing strip and support means adapted to secure the front facing strip at an entrance to an elongate ventilation slot formed through a building element, the support means including a linkage which includes a hinge for permitting rotation of the facing strip about a hinge axis substantially parallel to a longitudinal direction thereof, and wherein the linkage is adapted to permit one end of the front facing strip, once the ventilator is mounted on a building element, to move forward and backward relative to the building element independently from the other end of the front facing strip.

7. A ventilator as claimed in Claim 6 in which the linkage includes first and second linkage units spaced from one another along the length of the facing strip, each linkage unit connecting the facing strip to a support element of the support means.

8. A ventilator as claimed in Claim 7 in which each linkage unit includes a link element extending rearwardly from the front facing strip, a rear portion of the link element slidably engaging a receiver of the support member, and a front portion of the link element being connected to the front facing strip, for permitting slidable forward and backward movement of the facing strip.

9. A ventilator as claimed in Claim 8 in which one of the receiver and the link element rear portion includes a projection or recess which is selectively engageable with a series of recesses or projections in the other of the receiver and the link element, the series of recesses or projections being located at different distances behind the facing strip.

10. A ventilator as claimed in Claim 9 in which the projections and recesses are resiliently engageabi-e.

11. A ventilator as claimed in Claim 9 or Claim 10 in which the receiver comprises a channel and the link element includes a rod, the rod including a pair of substantially parallel legs having opposed projections thereon, both legs being received inside the channel of the support element, the channel having opposed faces, the series comprising a series of pairs of recesses located in opposing surfaces of the channel at different positions along the channel.

12. A ventilator as claimed in any one of Claims 7 to 11 in which each linkage unit includes a ball and socket joint, the position of the ball and socket joints of the first and second linkage units together defining the hinge axis.

13. A ventilator as claimed in Claim 12 in which the ball of each ball and socket joint is slidable in its socket along the longitudinal direction of the facing strip, the socket including elongate slots formed, generally aligned with the longitudinal direction of the facing strip, in opposed faces thereof with the ball being slidable along the slots.

14. A ventilator as claimed in Claim 12 or Claim 13 when dependent upon Claim 8 in which the ball and socket joint is located at a side of the link element which is adjacent a rear face of the facing strip.

15. A ventilator as claimed in Claim 12 or Claim 13 when dependent on Claim 8 in which the ball and socket joint is located on the rear portion of the link element, spaced from a rear face of the facing strip.

16. A ventilator as claimed in Claim 15 in which part of the link element forms part of an elongate rib running along the length of the rear face of the ventilator and extending rearwardly from the rear face, the ball and socket joint being connected to a rear edge of the rib.

17. A ventilator as claimed in Claim 16 in which the ball of the ball and socket joint is formed on the rear edge of the rib, and the facing strip, rib and ball are integrally formed.

18. A ventilator as claimed in Claim 15 or Claim 16 or Claim 17 in which the ball of the ball and socket joint is formed on the rear edge of the rib and the receiver of the support element comprises a channel, the ball being received inside the channel, the channel including a series of pairs of recesses located in opposing surfaces of the channel at positions spaced from each other in the rearward direction.

19. A ventilator as claimed in Claim 11, any preceding claim dependent upon Claim 11, or Claim 18 in which the channel includes further opposed faces which are at a slant to one another, the opposed faces and the further opposed faces defining a box-like retainer with a receiving opening adjacent the facing strip, the retainer narrowing, in the longitudinal direction of the facing strip, with increasing distance from the front facing strip.

20. A ventilator as claimed in Claim 11 or Claim 12, or any preceding claim which is dependent on either of these claims, in which the recesses comprise elongate slots aligned generally with the longitudinal direction of the facing strip.

21. A ventilator as claimed in Claim 20 in which the slots are shorter in length with increasing distance from the facing strip.

22. A ventilator as claimed in Claim 9 or Claim 10 in which the projections comprise a plurality of ball elements spaced from one another along a rod extending rearwardly from the facing strip, the receiver comprising a socket in the support element of the support means, each of the ball elements being selectively movable to engage the socket to form a ball and socket joint.

23. A ventilator as claimed in Claim 22 in which the rod extends rearwardly from a rear edge of an elongate rib which is located on a rear face of the front facing strip.

24. A ventilator as claimed in any one of the Claims 7 to 23 in which at least one of the linkage units includes an end stop for limiting forward movement of the facing strip relative to a said support element.

25. A ventilator as claimed in any one of Claims 7 to 24 in which the support means includes two separate said support elements, the support elements being adapted for securement at opposite ends of a ventilation slot through a building element.

26. A ventilator as claimed in any preceding claim in which the facing strip is substantially flat and an operating snib for positioning the facing strip comprises an integral extension of one end of the facing strip angled at a slant to the facing strip.

27. A slot ventilator substantially as described herein with reference to Figs. 1A and 1B, Figs. 2 and 3, Figs. 4, 5 and 6, Figs. 7, 8 and 9, or Figs. 10, 11 and 12 of the accompanying drawings.