WO1997019300A1

WO1997019300A1 - An air vent

Info

Publication number: WO1997019300A1
Application number: PCT/GB1996/002807
Authority: WO
Inventors: Paul Davidson
Original assignee: Barker, John, Arthur
Priority date: 1995-11-21
Filing date: 1996-11-18
Publication date: 1997-05-29
Also published as: GB9523802D0; AU7581596A

Abstract

An air vent includes one or more panels (2, 3), the or each of which includes at least one aperture (4, 5). The panels are relatively movable, to allow the apertures to move in and out of registration with each other by means of a heat-controlled actuator.

Description

AN AIR VENT

This invention relates to air vents, and more particularly to an air vent provided with means for opening and closing the vent in response to an environmental change-

Conventionally, an air vent comprises one or more apertured panels or grills. Where the air vent is provided with opening and closing means, two or more panels or grills may be provided which may be moved with respect to one another so as to increase the throughput of air across the air vent, decrease the throughput of air across the air vent or eliminate the throughput of air altogether. Typically, such an air vent may include a small handle or knob for moving by hand one grill or panel with respect to the other so opening or closing the vent.

Air vents may be constructed so as to remain permanently open with the result that air is continuously circulated. While this may be advantageous in warm weather, it may be particularly problematical in cold weather, since, circulation of cool air will further cool the inside of the building.

Air vents are often situated adjacent to air bricks, which bricks are typically placed towards the lower or upper portions of the wall of a building so as to be relatively inconspicuous. However they may also be relatively inaccessible to an operator for opening or closing, or for maintenance.

Often, an air brick and an associated air vent are placed adjacent to or behind a radiator attached to a wall of a building so that, when the radiator is on, the throughput of air through the air brick and air vent enables fresh warm air to be circulated in the building. However, such an arrangement also renders the air vent particularly inaccessible so that, even where an air vent which can be manipulated so as to be opened or closed is provided, access to the air vent and handle may be obstructed by the radiator.

Further, where a building is unoccupied for any length of time and the heating is switched off, continued ventilation through an open vent, particularly during winter months, can pose an additional problem. This is because further cooling of the building and pipes adjacent to the radiator may risk freezing the contents of the pipes, and lead to the possibility of burst or broken pipes and leakage.

Heat sensitive valves for controlling the flow of heating fluid to a radiator, and hence the amount of heating, are known and may comprise an heat sensitive wax filled expandable chamber having a reciprocating piston attached thereto.

In addition, thermostatically controlled devices are known for use in buildings including houses and other structures such as greenhouses for controlling the interior temperature. Typically, such devices incorporate thermometers and concomitant electronics for the operation and control of the heat source. However, such devices may require operator control or regular maintenance and are, therefore, inappropriate for many applications, particularly where the ventilation means is inaccessible or the building or other structure is unoccupied.

The object of the present invention is to overcome at least some of the above problems of the prior art by providing the air vent with environmentally sensitive actuating means.

According to a first aspect of the present invention there is therefore provided an air vent comprising one or more planar vent members adapted to open and close the air vent by relative movement therebetween, and a heat activated actuation means.

According to a preferred aspect of the invention there is provided a heat actuated air vent comprising: a first planar member having at least one aperture at a pre-determined location therein,

a second planar menber, overlapping and movable with respect to said first planar member, having at least one aperture at a pre-determined location therein, and

a heat activated actuation means arranged to act upon at least one of said planar members whereby the throughput of air from one side of the vent to the other can be controllably varied by said actuation means.

It will be appreciated that whilst the vent members have been described as planar, they are not necessarily flat, and could be curved or profiled, provided that they have a generally planar construction. Henceforth the planar members will be described in this specification as panels or panel members.

In a preferred embodiment, said aperture in said first panel is brought partly or wholly into or out of register with respect to said aperture on said second panel by said actuation means so as to control the throughput of air from one side of the air vent to the other.

Further, in a preferred embodiment of the invention, the heat actuated air vent is arranged so that on an increase in environmental temperature the throughput of air across the vent is increased and on cooling of the environmental temperature the throughput of air across the vent is decreased.

In another preferred embodiment, the air vent is adapted so that, in the absence of sufficient impulse from the actuation means, the panels automatically adopt a predetermined orientation one with respect to the other. Preferably, this takes place under the action of gravity. Alternatively, means are provided for restoring the panels to this predetermined orientation, which can, for example, be resilient and preferably may comprise a compression or torsion spring means.

In a further preferred embodiment, said panels are slidably or rotatably movable one with respect to another. Preferably, said panels are rotatably movable with respect to one another about a common axis. Preferably, the first and second panels are substantially circular and superimposed, the panels being adapted so that one panel is rotatable with respect to the other panel about a common axis perpendicular to the planes of the panels. Alternatively, or in addition, one of the panels comprises at least one louvre or slat adjacent to said at least one aperture, which louvre or slat is controllably rotatable by said actuation means so that the throughput of air across the air vent can be controlled. Preferably two or more substantially parallel louvres or slats are provided.

In a further preferred embodiment, the heat activated actuation means comprises a thermally expandable or recoverable material. Preferably, the actuation means comprises a chamber containing a material which expands on heating and contracts on cooling. The material may comprise wax or any other suitable material or combination of materials known to those skilled in the art. Preferably, the actuation means comprises a reciprocating piston which reciprocates, for example, on heating and cooling of the material within the chamber. The chamber may alternatively be collapsible, and comprise at least one expandable wall. Preferably, the wall is convoluted. Preferably the chamber comprises a cylinder having one or more convoluted walls so as to provide a collapsible chamber which preferably functions as a piston. Other embodiments such as flexible, collapsible walls, resilient walls and walls comprising portions which are slidable one with respect to another may be used as would be well understood by those skilled in the art.

Preferably, the heat activated actuation means comprises a portion which acts on one of said panels to cause movement thereof. The portion may comprise a cap which fits over the piston or the expandable chamber. In a further aspect of the invention, there is provided an air vent as herein described with reference to and/or as illustrated in the accompanying Drawings.

In a further aspect of the invention, there is provided an air venting system comprising an air vent as herein described with reference to and/or as illustrated in the accompanying Drawings and an air brick.

In a further aspect of the invention, there is provided a heat activated actuation means as herein described with reference to and/or as illustrated in figures 3, 6 and/or 7 of the accompanying Drawings.

Preferred embodiments of the invention will now be described, by way of example only, with reference to and/or as illustrated in the accompanying Drawings in which:

Figure 1 shows a cross sectional view of an air vent in accordance with the invention.

Figure 2 shows front views of the front and back apertured panels of an air vent in accordance with the invention. Figure 3 shows a cross sectional view of a heat activated actuation means in accordance with the invention.

Figure 4 shows a front view of an alternative air vent in accordance with the invention.

Figure 5 shows a partially perspective view of an alternative air vent according to the invention.

Figure 6 shows a partially cut away perspective view of a heat activated actuation means in accordance with the invention when cold.

Figure 7 shows a partially cut away perspective view of a heat activated actuation means in accordance with the invention when warm.

Referring now to Figures 1 and 2, a heat actuated air vent, generally indicated at 1 is shown. Air vent 1 comprises a front panel 2 having a number of apertures 4 and outwardly extending projecting edges 2A and 2B. In addition, air vent 1 comprises a rear panel 3 comprising apertures 5. Panel 3 is fixedly located in a wall of a building or other structure or the like.

Panel 2 is slidably movable with respect to panel 3 in the direction of the arrows as shown. Means for maintaining the lateral position of panel 2 with respect to panel 3 during sliding is provided (not shown) as would be well understood by those skilled in the art.

A heat activated actuation means, generally indicated at 9, comprises a wax filled collapsible chamber 8 and a cap 7 arranged to act on projecting edge 2B of panel 2. Heat activated actuation means 9 is situated in a plastic case 6.

Whilst panels 2 and 3 are referred to as front and rear panels in this particular embodiment, it may be that panel 2 is rearwardly located with respect to panel 3 having regard to the outer surface of a structure in which panel 3 is located as will be well understood by those skilled in the art.

Chamber 8 is filled with wax, or any other suitable material, and is provided with collapsible walls so that on heating of the wax, chamber 8 expands and forces cap 7 to engage edge 2B pushing panel 2 in the direction of arrow 20 so that apertures 4 and 5 start to overlap. As heating is continued, the degree of overlap commences and increases thereby increasing the passage of air from one side of the vent to the other. On cooling of the wax, chamber 8 collapses and contracts and spring 19 forces panel 2 to move in a direction opposite to arrow 20 so that the degree of overlap between apertures 4 and 5 is reduced or eliminated altogether thereby decreasing, or eliminating, the flow of air from one side of the vent to another.

If the air vent is arranged so that the motion of panel 2 in the direction of arrow 20 is in a vertical direction, panel 2 will tend to fall as chamber 8 contracts on cooling so reducing the degree of overlap between apertures 4 and 5 or even eliminating the degree of overlap so as to cut off the air flow across the vent. Thus, gravity may cause panel 2 to adopt a closed position relative to panel 3 on deactivation, in this case cooling, of actuation means 9. Therefore, spring 19 may not be required.

In the following figures like referenced numerals refer to afore like referenced features.

Referring now to Figure 3, an alternative heat activated actuation means 9 is shown. Here, actuation means 9 comprises a chamber 10 filled with wax 11 and a movable piston 12 which seals chamber 10 and moves with respect to chamber 10 on heating and cooling as shown. The outer surface of 13 of piston 12 is adapted to engage the movable panel. This is illustrated more clearly in Figure 4 wherein piston 12 engages a projection 15 on the side of panel 2 at surface 13.

One or more springs 16 or 17 may be provided for ensuring that panel 2 has a tendency to adopt a closed position unless forcibly opened by piston 12 on heating of wax 11.

Spring 16 is connected under tension between panel 2 and chamber 10, whereas spring 17 is attached under tension between panel 2 and a portion of an external structure 18.

On heating of wax 11, for example, if the temperature of the surroundings increases, the volume of wax 11 increases, forcing piston 12 to move upwardly as shown in figures 3 and 4 and to engage projection 15 of panel 2. Panel 2 is thus forced upwardly so increasing the degree of overlap between apertures 4 and 5 and hence the throughput of air. On cooling of the wax, its volume decreases and piston 12 falls under the action of gravity and, in this embodiment, also under the action of springs 16 and 17 so that the degree of overlap between apertures 4 and 5 is reduced or eliminated altogether thus altering the flow of air through the vent.

The degree of overlap between apertures 4 and 5 is illustrated at 21. The action of springs 16 or 17 is to reduce or eliminate the degree of overlap 21 whereas, on heating, wax 11 expands and acts in an opposing manner to the springs so that piston 12 engages projection 15 and the degree of overlap 21 is increased. In this manner, the throughput of air from one side of the vent to the other can be controlled. Indeed, the degree of overlap, and hence air throughput can be continuously controlled.

As will be appreciated by those skilled in the art, the heat actuation means is self operating and regulating since on heating ventilation is increased automatically and vice versa. Thus no external operation is required. This is particularly useful for air vents which may be inaccessible or infrequently maintained if maintained at all.

Means may be provided for adjusting the springs 16 or 17 in the embodiment shown in Figure 4 or spring 19 in the embodiment shown in Figure 1 or indeed the position of the heat actuation means 9 with respect to panels 2 and 3 so that the change in temperature required to open or close the vent can be controlled. Such means may comprise a means for tensioning or detensioning springs 16, 17 or 19. Alternatively, such means may comprise a means for raising or lowering the heat actuation means with respect to panels 2 and 3. Referring now to Figure 5, an alternative embodiment of an air vent is shown. Here, panels 16 and 17 comprise a plurality of apertures distributed about a central axis in circular panels 16 and 17. For clarity, panels 16 and 17 are illustrated slightly displaced to one side with respect to each other and faced apart.

Panel 16 is rotatable with respect to panel 17 about an axis AA' which pass through the centre of the panels in this particular example. Heat actuation means 9 engage projection 15 so as to rotate panel 16 with respect to panel 17. In this particular situation illustrated, actuation means 9 is partially extended so that there is some degree of overlap between the apertures in panels 16 and 17 and air can pass from one side of the air vent to the other.

It will be apparent to those skilled in the art that the present invention may be used (not shown) with a panel comprising one or more louvres or slats which are positioned adjacent one or more apertures in the panel. The panels are arranged so that one or more corresponding apertures in the other panel are provide opposite said aperture and louvre or slat in the first panel. On activation, the one or more louvres or slats are rotated about an axis parallel to and displaced from the other panel so that the apertures are opened or closed so as to increase or decrease the throughput of air through the vent.

Referring now to paragraphs 6 and 7, the heat actuation means 9 seen in Figures 1 and 5 is shown in more detail. Here, chamber 8 comprises convoluted, or as shown here concertinaed, walls 8A so that chamber 8 is expandable and collapsible. Chamber 8 is sealed and contains an expandable substance such as wax inside. Any other suitable substance known to those skilled in the art may be used. Chamber 8 is here cylindrical, has a cap 7 and functions as a piston. When cold, chamber 8 contracts and cap 7 retracts until it is adjacent to or within tube 6. The piston, cap and tube 6 may comprise any suitable material and will typically comprise plastic or be composed substantially or partially of plastic. Chamber 8 may be substantially circular or polygonal, such as square or rectangular, in cross section.

When warmed or heated, chamber 8 expands and the continuous concertinaed wall 8A extends raising cap 7 above the level of tube 6 so as to act on panel 2 as illustrated in figures 1 or 3 or to act on a louvred or slatted panel(not shown).

Alternative heat activation actuation means such as bimetallic strips, heat recoverable materials such as plastics or metals, particularly those wherein the heat recovery is reversible, and any other heat activation actuation means known to those skilled in the art, may be used without departing from the scope of this invention.

It will be apparent to those skilled in the art from the enclosed that the invention of this application provides a stand alone heat actuated air vent which does not require a human operator. This is particularly advantageous when the air vent is located adjacent or behind a radiator since it may be difficult to access the air vent for human operation thereof. Furthermore, the air vent of the invention will enable cool air to be drawn into and passed over the radiator surface when the heat activation actuation means is warmed sufficiently by the radiator so that the air vent is partially or wholly opened. In contrast, when the radiator is cooled, the air vent can be partially or wholly closed so that less air is circulated.

It will be apparent to those skilled in the art that, whereas the embodiments described in this application relate to an increase in air flow on heating and a decrease in air flow on cooling, it is within the scope of this application for the air flow to be increased on cooling and decreased on heating if the particular application of the air vent requires this.

Claims

1. An air vent comprising one or more planar vent members adapted to open and close the air vent by relative movement therebetween, and actuation means activated by heat to effect such relative movement.

2. An air vent according to Claim 1 and comprising a first planar member having at least one aperture therein, a second planar member, overlapping and moveable with respect to said first planar member, having at least one aperture therein, and in which the actuation means are arranged to act upon at least one of said planar members whereby the throughput of air from one side of the vent to the other can be controllably varied by said actuation means.

3. An air vent according to Claim 2 wherein said actuation means effects relative movement between said planar members so as to bring the or each aperture in said first planar member into or out of register with respect to the or each corresponding aperture in said second planar member.

4. An air vent according to any of the preceding claims wherein the actuation means are arranged so that, on an increase in environmental temperature, the throughput of air across the vent is increased and. on cooling of the environmental temperature, throughput of air across the vent is decreased.

5. An air vent according to any of the preceding claims including two planar vent members which are arranged so that a biassing force acts on at least one vent member, said force urging the vent members to take up pre-determined positions relative to each other.

6. An air vent according to Claim 5 wherein the biassing force is the action of gravit> .

7. An air vent according to Claim 6 wherein the biassing force is provided by spring means.

8. An air vent according to any of the preceding claims wherein the actuation means comprises thermal expandable or recoverable mateπal

9. An air vent according to any of the preceding claims in which the actuation means comprises a chamber containing a material which expands on heating and contracts on cooling.

10. An air vent according to Claim 9 in which the actuation means comprises a reciprocating piston which reciprocates on heating and cooling of the material within the chamber

1 1. An air vent according to Claim 8 wherein the chamber is collapsible and includes at least one expandible wall.