GB2552767A

GB2552767A - Automatic opening vent

Info

Publication number: GB2552767A
Application number: GB1609948.3A
Authority: GB
Inventors: Harrison Robert; Phillip Greaves Ian
Original assignee: Linear Building Innovations Ltd
Current assignee: Linear Building Innovations Ltd
Priority date: 2016-06-07
Filing date: 2016-06-07
Publication date: 2018-02-14
Anticipated expiration: 2036-06-07
Also published as: GB2552767B; GB201609948D0

Abstract

A vent having a metal frame 12, a door 14 moveable within the frame, and an automated opening mechanism (16, Fig. 4), the frame and door having front surfaces which are co-planar when closed. The opening mechanism may be a motorized mechanism located on the rear of the door, concealed from view in use, and controlled by a sensor as part of a smoke ventilation system e.g. operated on detection of heat or smoke. The frame may be made from sectional components welded together, and may have an extending flange 36, perforated for receiving plaster. The flange may have plaster guide formation in the form of a lip (18, Fig. 6). In use plaster may be applied to the edge of the opening so that the vent is flush with the surrounding wall into which it is mounted, and the door may be decorated to match the surroundings. Also claimed is a method of fitting the vent into a building, and a smoke ventilation system including the vent.

Description

(54) Title of the Invention: Automatic opening vent

Abstract Title: Vent with co-planar frame and door for flush mounting into wall (57) A vent having a metal frame 12, a door 14 moveable within the frame, and an automated opening mechanism (16, Fig. 4), the frame and door having front surfaces which are co-planar when closed. The opening mechanism may be a motorized mechanism located on the rear of the door, concealed from view in use, and controlled by a sensor as part of a smoke ventilation system e.g. operated on detection of heat or smoke. The frame may be made from sectional components welded together, and may have an extending flange 36, perforated for receiving plaster. The flange may have plaster guide formation in the form of a lip (18, Fig. 6). In use plaster may be applied to the edge of the opening so that the vent is flush with the surrounding wall into which it is mounted, and the door may be decorated to match the surroundings. Also claimed is a method of fitting the vent into a building, and a smoke ventilation system including the vent.

At least one drawing originally filed was informal and the print reproduced here is taken from a later filed formal copy.

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Application No. GB1609948.3

RTM

Date :15 November 2017

Intellectual

Property

Office

The following terms are registered trade marks and should be read as such wherever they occur in this document:

Geze

Rockwall

Intellectual Property Office is an operating name of the Patent Office www.gov.uk/ipo

AUTOMATIC OPENING VENT

The present invention relates to an automatic opening vent such as a door or window that can be opened automatically upon detection of a certain event. Such vents are useful in particular for providing automated ventilation within a building, but the present invention is more particularly suited as an automated vent for a building’s smoke ventilation system - part of its fire safety system.

Automatic opening vents are well known in the art and are typically provided with a switch or sensor that allows a motorized opening mechanism to be triggered when a predetermined event occurs, such as an increase or decrease in temperature, or the detection of a fire or smoke, or upon the triggering of a building’s fire alarm. Typically such vents comprise a frame, a door or window and an automated opening mechanism connected to a switch or sensor, for example of a fire alarm system. Such vents typically are arranged to be highly visible as they need not to be blocked. Furthermore, the opening mechanism is typically on the front of the door or frame, with the door or window being arranged to open away from it. Yet further, for smoke vents, the frame and door or window are usually fairly heavy duty in view of their requirement to meet fire regulations.

Building designers are now looking for more subtle arrangements for such vents so as not to intrude upon the visual appeal of the decorative finish of the building. It would be desirable, therefore, to provide an automatic opening vent with a more subtle design.

According to the present invention there is provided an automatic opening vent comprising a metal frame, a door fitted within the frame, and a door opening mechanism for automated opening of the door relative to the frame, wherein the frame has a front-most plane, the door has a front surface and the front surface of the door is substantially co-planar with the front-most plane of the frame when the door is closed. By being substantially co-planar, the automated opening vent of the present invention can become a concealed automatic opening vent upon installation in a wall - for this effect to be achieved, the frame of the vent will not be over-fitted with an architrave during the installation thereof. Further, the door will typically have a flat and plain front surface, i.e. a matching surface finish to the walls - walls are typically likewise flat and plain. It is to be appreciated, however, that surface decoration may be provided, so the door can be arranged to match the walls, thus concealing it within any pattern of the wall, e.g. with matching wallpaper.

Preferably the door opening mechanism is mounted at a rear of the door, either directly or on a mounting flange or platform, and connects to the frame. Alternatively it might be mounted on a rear of the frame, or within the frame, it then being connected to the rear or a side flange of the door for opening thereof. The door opening mechanism is thus fully concealed from view at the front of the vent while the door is closed.

Preferably the frame’s front-most plane is defined by a plaster-guide formation, such as a corner ridge extending around the frame, with its front-most edge providing both the frame’s front-most plane and a line to which the installer can plaster the wall that surrounds the frame.

Preferably the frame comprises at least one folded metal section, with a least one of the folds forming the corner ridge, or the frame’s front-most plane.

For a rectangular frame, the frame may be formed from four sectional components, two defining sides and two defining a top and bottom of the frame. This will typically be fitted in a wall with the sides arranged to stand vertically.

The frame’s front-most plane will typically be extended frontwards of a sideward extending flange of the frame, the sideward extending flange potentially being perforated, or otherwise roughened, to facilitate grab of plaster thereon upon the installation of the frame within a wall.

Generally speaking each sectional component of the frame will have such a flange as usually the vent is installed above ground level - raised above the ground in a wall. However, for a floor-mountable arrangement, the bottom sectional component might not have such a flange as the frame can then sit on the floor, with the wall built around it.

Multiple sectional components for the frame may be welded together to form a fixed frame. Another approach could be to take a single sectional component that is folded or bent into a desired shape and its tree-ends then welded together to form the fixed frame shape.

Preferably the corners of the frame, and particularly the flanges when provided, are formed from chamfered ends of the frame components, i.e. with a bevel cut, to thus offer a more complete frame shape when viewed from the front.

Preferably the frame components are made of a metal such as steel or aluminium. They may be painted.

Preferably the door is also made of metal, although it will typically additionally be infilled with an insulating material.

Preferably the frame is square or rectangular. The door will have a shape to match.

Preferably two opposing parts of the frame, usually a top and bottom, have provided therein pivot pins or pivot holes for pivotal mounting of the door within the frame using suitably positioned pins or holes on the door, e.g. in a top and bottom thereof, or in opposing sides. Generally speaking the frame has one pin and one hole, and the door has a corresponding hole and pin. The pin in the door is typically moveable, although it can be a pin in the frame that is moveable. By being movable, the door can be easily fitted and removed.

Preferably the door is square or rectangular so as to match the shape of the frame, i.e. a central opening therein.

Preferably the door has a fire seal extending around its perimeter.

Preferably the fire seal engages against the inside surfaces of the frame when the door is closed.

Preferably the hinge pins include a fixed hinge pin on one side of the door and a movable hinge pin on the opposing side of the door, or the corresponding part of the frame. This allows, by movement of the movable hinge pin, the removal of the door from the frame.

Preferably the hinge pins are steel or aluminium hinge pins.

Preferably, for a square or rectangular frame, the inside walls of the frame are flat around three sides thereof. A fourth inside wall of the frame may instead have a step to act as the door-stop. As the other three are flat, the door, upon rotation, can freely open and close rearwardly. The step, as a door-stop, however, can support the hinged end if the hinges fails, thus, together with the door opening mechanism, preventing the door from falling inward of the frame unless driven by the door opening mechanism.

Preferably the door hinges in a rearward direction as that then will not intrude into the room, thus avoiding risk of malfunction in the event of an obstacle being located in front of the vent - such vents are typically installed to open into a smoke ventilation shaft, whereby an obstacle cannot be located behind the door, but they can be located in front of the door, even though they shouldn’t be.

Preferably the frame components have the sideward extending flange at a front end thereof and a further sideward extending flange at a rear end thereof, to define an approximate U section. The further sideward extending flange is preferably shorter than the first. Both sideward extending flanges offer stiffness and rigidity to the frame. The frame, by also being metal, is thus substantially rigid once all folded and welded together into a ring or loop.

The step also assists with the frame’s rigidity, and with the fitting of the door to the frame as it allows the door more readily to be controlled during the fitting of the door through the movement of the movable pin into its respective hole, either in the frame or the door.

Preferably the door is also formed from folded metal sheets.

Preferably the door comprises a front face which is generally flat. This allows it to blend with a substantially flat plaster surface on the wall in which the door and frame will be fitted.

Preferably the front of the door is formed from a sheet that is bent rearwardly at both ends to provide edges of the door. Preferably a first edge extends rearwardly to define a flat surface thereon. On that flat surface, a fire seal may be fitted such as with adhesive or self -tapping screws or plugs fitting within holes within the flat surface.

At a rear end of this first edge, a further flange may be provided - extending outwardly, sideways. It defines a bearing surface by way of which the door cannot open forwardly - it will bear against the frame upon any such attempt.

This outwardly extending further flange at the rear of the door, is spaced at the distal end of the door from the hinge point. It defines a door closure guide. The door closure guide prevents outward opening of the door as it will bear upon the rear flange of the frame component upon attempting to open the door outwardly.

The length of the first edge’s rearward extension is slightly greater than the width of the frame. Its length determines the flushness of the front surface of the door relative to the front-most plane of the frame when the door is closed. It can be fitted with a fire seal if desired, and is thus provided with an appropriate length for that purpose.

Preferably the second edge of the door, which also rearwardly extends from the front, defines a further flat side surface for the door. That further flat side surface may likewise be fitted with a fire seal in the same or similar manner described above.

The second edge, at its rearmost end, has an inwardly extending flange, preferably less rearwardly positioned than the outwardly extending further flange of the first edge as it will oppose the step that provides the door-stop. A back plate of the door can be fitted onto that inwardly extending flange, such as by welding (typically spot welding) or with bolts, screws or glue.

The first edge is provided distal to the hinge side of the door. It thus may be required to carry the automated door opening mechanism. Preferably, therefore, the door is fitted with the automated door opening mechanism which comprises a motorized opener and an opening or extending member. The extending member will mount to the frame at a free end thereof, whereas the motorised mechanism can mount to the door. Other arrangements may have these the other way around.

Such opening mechanisms are well known in the art and many variations can be utilised with the present invention.

For providing stiffness to this free end of the door, as it will carry the forces of the door opening mechanism, it is preferred to provide a further metal component at its end to define a Z shape reinforcement thereat. This is rather than just having the back plate of the door mounted onto the first edge of the door. The further metal component is a folded component with a bottom that can be welded or otherwise attached to the rear of the front surface of the door, and a top that can have its free end attached to the inside of the first edge of the door and a further part of that top being attached to the back plate of the door. The edge of the back plate of the door is thus mounted onto the top of the Z to define a double thickness of metal. Into this double thickness, the mounting frame for the motorised mechanism of the door opening mechanism can be attached. More preferably, however, a further box section, or folded member can be attached there to act as a spacer, i.e. the mounting flange or platform for the door opening mechanism, thus then allowing the motorised mechanism to be mounted more flush with the rear of the frame. This thus provides a solid fixing for the motorised mechanism, and a good edge stiffness for the door (typically along its height) to provide rigidity for the door’s free end.

The door is preferably rectangular and thus it further preferably has two additional sides - a top and a bottom. Preferably the top and bottom likewise have flat surfaces thereon. However, in a preferred embodiment a rear edge of the top and bottom sides has a ridge extending outwardly thereon defining a lip for better retention of a fire seal thereagainst. This lip is entirely optional. However, it is preferred. It also provides significant rigidity to the door along that extent thereof - typically along the length of the door.

Preferably the cavity within the door as defined between the front surface of the door and the back plate of the door can be infilled with an insulating material, such as RW3 Rockwall infill. The box section or area segregated by the Z may likewise be infilled with an insulation material.

Instead of the fixed hinge pin for the door being provided on the door, the fixed hinge pin may be instead provided in one of the frame components with the door then having an aperture for sitting over that fixed hinge pin.

Preferably the door is at least 40mm thick, and most preferably it is about 43mm thick.

Preferably the sideways extending flange of the frame onto which holes are provided for plastering is at least 30mm deep, and more preferably about 35mm deep.

Preferably the depth of the frame components for defining the depth of the frame is at least 80mm deep and more preferably about 83mm deep.

Preferably the step in the one frame component is at least 4mm further rearward from the front edge of its frame component than the thickness of the door, and most preferably for an approximately 43mm door, it is about 47.5mm from the leading or front surface of the frame.

Preferably the movable pivot on the door is a sliding bolt pivot with a release catch and a spring for allowing the latch to be pulled rearward for removal of the door.

Other movement arrangements may instead be provided to allow release of the door. A hinge or pin might instead even be just screwed thereon in a fixed position once the door is fitted within the frame. This, however, makes the door less readily removable so it is less preferred.

Preferably the door is fitted with a hole at its hinge end for allowing a power cable for the motorised mechanism to be threaded through the door and out at the hinge side thereof. Thus, despite the motorised mechanism being at the opening end of the door, the cable therefor can be concealed.

Due to the thickness of the door being less than the thickness of the frame, the actuator or door opening mechanism may need to be spaced rearwardly from the rear surface of the door. For this purpose, the further box section is a preferred feature at the rear distal edge of the door. This further box section will also provide additional stiffness for the door. It will typically increase the thickness of the door at that part thereof to match the depth of the rearwardly extending side of the door. The bracket for the actuator can thus then be fitted onto that box section.

In place of a box section, a further Z section may be provided, or some other section.

Preferably the motorized door opening mechanism comprises an actuator with a motor for driving a chain push mechanism. Suitable such mechanisms are available from Geze. These can comprise a chain that has only one direction of flexibility, whereby it can be contained within a drive housing and upon extension it can provide a pushing force.

Typically the present invention is fitted in a wall as part of a smoke ventilation system. The present invention thus also comprises a smoke ventilation system for a building comprising a vent as described above.

The present invention also comprises a method of installing an automatic opening vent, the method comprising providing an automatic opening vent as described above, fitting it in a wall with a front thereof facing into a room or corridor of the building, and the rear facing a ventilation space of the building, such as a ventilation shaft. Preferably the installation involves plastering over a flange of the frame up to the front-most plane of the frame.

These and other features of the present invention will now be described in greater detail with reference to the accompanying drawings in which:

Figure 1 schematically shows a perspective view of a first embodiment of an automatic opening vent in which the drive mechanism has not yet been installed;

Figure 2 schematically shows the same automatic opening vent, viewed from the other side, in which the door is almost closed;

Figure 3 is a further schematic view of the same automatic opening vents with the door almost fully open;

Figure 4 schematically shows a typical vent opening mechanism fitted to a door and frame for illustrating how it opens the vent;

Figures 5 and 6 schematically show a vent opening mechanism mounted to the rear of a door of a second embodiment, on a box section, from a side thereof, and a top thereof, respectively;

Figure 7 schematically shows the embodiment of Figures 5 and 6, but with the vent being opened through the driving of a chain-pusher by a motor within the actuator of the door opening mechanism;

Figure 8 schematically shows this second embodiment of automatic opening vent, omitting the door opening mechanism, from the top, showing typical dimensions of the thickness of the various elements;

Figure 9 schematically shows the embodiment of Figure 8, but from a side, for showing an example hinge pin arrangement; and

Figures 10 and 11 schematically show fire seals for the vent of Figures 5 to 9.

Referring first of all to Figure 1 there is shown an automatic opening vent 10 not yet fitted with a door opening mechanism 16. The door opening mechanism 16 can be seen, by way of two schematic examples, in Figures 4 to 7. Suitable mechanisms are available from companies such as Geze, with one suitable range of products being their chain drive system, as typically provided for automated opening or closing of windows.

The vent 10 comprises a metal frame 12 and a door 14 fitted within the frame 12. Once fitted, the door opening mechanism 16 can automatically open the door relative to the frame when a control system instructs it to do so - e.g. from a fire alarm system.

The frame 12 has plurality (herein four) of sectional components 30, 32, 34 that are welded 40 together to form, at a protruding, front, corner ridge 18, a front-most plane of the frame 12 that will correspond to the level to which plaster will be applied over the sides 36 of the frame 12 during the frame’s installation.

The door 14 instead has a flat front surface 20 and the front surface 20 of the door 14 is substantially co-planar with the front-most plane 18 of the frame 12 when the door 12 is closed, as can be seen in Figures 5, 6 and 8 to 11. By being substantially co-planar, the automated opening vent 10 of the present invention can become a concealed automatic opening vent upon installation in a wall - for this effect to be achieved, the frame 12 of the vent 10 will not be over-fitted with an architrave during the installation thereof.

For different wall finishes, the door may have a different surface finish, i.e. a surface finish that instead matches the wall finish. Surface decoration may also be provided, so the door can be arranged to match the walls, thus concealing it within any pattern of the wall, e.g. with matching wallpaper.

As can be seen in Figure 4, and in Figures 5 to 7, in the preferred arrangement the door opening mechanism 16 is mounted at a rear 22 of the door 14, herein indirectly via a mounting flange or platform such as the illustrated box section 24. The door opening mechanism is also connected to the frame via, in this embodiment, a chain extending from the drive mechanism - see Figures 4 and 7. Such a mechanism or actuator arrangement may be one of the mechanisms sold by Geze.

The frame's front-most plane is defined by a plaster-guide formation, such as a corner ridge 18 extending around the frame 12, with its front-most edge providing both the frame’s front-most plane and a line to which the installer can plaster the wall that surrounds the frame.

The frame comprises four folded metal section, with a least one of the folds forming the corner ridge, or the frame’s front-most plane 18. Two of the sectional components define sides and two define a top and bottom of the frame. The frame’s front-most plane is extended frontwards of a sideward extending flange 36 of the frame 12, the sideward extending flange 36 being perforated, or otherwise roughened, to facilitate the grab of plaster thereon upon the installation of the frame 12 within a wall.

The frame components are made of a metal such as steel or aluminium. They may be painted. The door is also made of metal, although it will typically additionally be infilled with an insulative material.

The frame is rectangular in this embodiment and the door has a shape to fit within its central opening.

The top and bottom of the frame has, respectively, a hole 50 and a fixed pin 46 and the door 14 has correspondingly positioned movable pin 48 and hole 50, the pins being pivot pins for pivotal mounting of the door within the frame using the suitably positioned pins or holes in the relevant side area of the frame. Since the pin in the door is moveable, the door can be easily fitted and removed from the frame. Referring to Figure 9 it can be seen that the pin is like a gate bolt, but is sprung into its extended position, but has a handle to allow its retraction. It is also mounted on a bracket within the door, which bracket serves to reinforce that part of the door. The bracket can be made of folded metal sheet welded to the door.

As can be seen in Figures 10 and 11, and in Figures 1 to 3, the door has a fire seal 52 extending around its perimeter. The fire seal is for engaging against the inside surfaces of the frame 12 when the door 14 is closed, as can be seen in Figs 10 and 11.

Referring next to Figs 10 and 11, the frame 12 has three inside walls 54 that are flat the left side of Fig 10 and the two sides of Fig 11. The fourth inside wall of the frame 12 is shown in Fig 10 to instead have a step 66 to allow that wall to act as the door-stop 68. As the other three are flat, the door, upon rotation, can freely open and close rearwardly, as shown in Fig 7. The step 66, acting as a door-stop 68, however, can support the hinged end of the door, e.g. during installation of the door within the frame, or if the hinges fails.

Referring now to Figure 3, the sideward extending flange 36 at a front end thereof, the flat inside surface 54 and a further sideward extending flange 56 at a rear end of one of the sectional components 30 define an approximate U section for that sectional component. The sectional components for the top 32 and bottom 34 are similar, but shorter in this embodiment as the frame 12 is rectangular. The further sideward extending flanges 56 are each preferably shorter than the first or perforated flanges 36. Both sideward extending flanges 36, 56 offer stiffness and rigidity to the frame 12. The fourth sectional component has the folded inside surface for providing the step and door stop, so it is additionally stiff. The frame, by also being metal, is thus substantially rigid once all folded and welded together into a ring or loop.

Preferably the door is also formed from folded metal sheets, as can be seen in Figures 10 and 5 to 7.

As can be seen in Figure 11 - effectively a vertical section through the door, the door 14 is formed from a front sheet 20 that is bent rearwardly at both ends to provide top and bottom edges 58, 70 of the door 14. Preferably a first edge 58 extends rearwardly to define a flat surface 60 thereon. On that flat surface 60, a fire seal 52 is fitted (see Fig 11) such as with adhesive or self -tapping screws or plugs fitting within holes within the flat surface. Then at a rear end of this first edge a lip 90 is provided along with a return 92. The return allows a back plate 80 to be welded to the back. The other end is similar. The lip 90 is optional but preferred as it serves to better close the top and bottom of the door, especially in combination with the seal 52.

Referring then to Figure 10, a horizontal section is instead shown. The lips are not present in this axis as the door needs to pivot to open. As a result, although the front 20 and the first part of the edges 58, 70 are similar to that of Figure 11, the rear ends of those edges are different:

The first edge 58, now forming the left side of this embodiment, extends additionally rearward to its rear end 62, whereat a further flange 64 is provided - extending outwardly, sideways. It defines a bearing surface 65 by way of which the door 14 cannot open forwardly - it will bear against the frame 12 upon any such attempt.

This outwardly extending further flange 64 at the rear of the door 14, is spaced at the distal end of the door 14 from the hinge point 46 (See Figure 8). It defines a door closure guide. The door closure guide prevents outward opening of the door as it will bear upon the rear flange 56 of the frame component upon attempting to open the door outwardly.

The length of the first edge’s rearward extension is slightly greater than the width of the frame. Its length determines the flushness of the front surface of the door relative to the front-most plane of the frame when the door is closed.

As shown in Figure 10, it can be fitted with a fire seal if desired, and is thus provided with an appropriate length for that purpose.

Referring sill to Figure 10, the second side edge 70 of the door 14 also rearwardly extends from the front 20, but it tapers inwardly in this embodiment. It again has an inward flange 78 at its rearmost end 76 for attachment to the back plate 80. Further, it also again defines a further flat side surface for the door which may likewise be fitted with a fire seal 52, for example in the same or similar manner described above.

The back plate 80 of the door can be fitted onto the inwardly extending flange 78, such as by welding (typically spot welding) or with bolts, screws or glue.

The first side edge 70 as shown in Figure 10, and figure 5, is distal to the hinge side of the door. It thus is required, in this embodiment, to carry the automated door opening mechanism 16. Preferably, the automated door opening mechanism comprises a motorized opener 94 and an opening or extending member 96 - see Figures 4 and 7. The extending member 96 will mount to the frame 12 at a free end thereof, typically, as shown, using a bracket, whereas the motorised mechanism 94 can be mounted to the door, e.g. via a mounting bracket or box section 24.

For providing stiffness to this free end of the door 14, a further folded metal component 82 is also provided at this end. In this embodiment it defines a Z shape reinforcement thereat. The further metal component 82 is a folded component with a bottom 84 that can be welded or otherwise attached to the rear 86 of the front surface 20 of the door 14, and a top 88 that can have its free end attached to the inside of the first side edge 58 of the door 14 and a further part of that top 88 being attached to the back plate 80 of the door 14. That edge of the back plate 80 of the door 14 is thus mounted onto the top of the Z to define a double thickness of metal, which is thus relatively stiff, especially as it is backed by the middle section of the Z 82. Into this double thickness, the mounting frame 24 for the motorised mechanism 94 of the door opening mechanism 16 can be attached. More preferably, however, a further box section 24 as shown, or a further folded member, can be attached there to act as a spacer, i.e. the mounting flange or platform for the door opening mechanism, which thus then allows the motorised mechanism to be mounted generally flush with the rear of the frame 12. This thus provides a solid fixing for the motorised mechanism 94, and a good edge stiffness for the door 14 to provide rigidity for the door’s free end.

The door thus assembled will have a cavity within it. That can be infilled with an insulating material 44, such as RW3 Rockwall infill. The box section or area segregated by the Z may likewise be infilled with an insulation material if desired.

Typical sized for a smoke ventilation vent are shown then in Figure 8. As can be seen, one embodiment has the door having a thickness of at least 40mm - this embodiment has it about 43mm thick. The sideways extending flange of the frame onto which holes are provided for plastering is then at least 30mm deep, and more preferably about 35mm deep as shown. Variations are of course possible.

The depth of the frame components in this embodiment are at least 80mm deep and more preferably about 83mm deep as shown.

The step in the one different frame component is at least 4mm further rearward from the front edge of its frame component than the thickness of the door, and most preferably for an approximately 43mm door, it is about 47.5mm from the leading or front surface of the frame as shown. The step, however, might be omitted entirely, or it may be differently positioned, e.g. to accompany a different door, or a different fire seal arrangement.

Finally, as can be seen in Figures 2 and 4, the door can be fitted with holes at its distal end and at the hinge end for allowing a power cable for the motorised mechanism 94 to be threaded through the door 14 and out at the hinge side thereof. Thus, despite the motorised mechanism 94 being at the opening end of the door, the cable therefor can be concealed.

In the embodiment of Figures 5 to 11, due to the thickness of the door being less than the thickness of the frame, the actuator or door opening mechanism is spaced rearwardly from the rear surface of the door by the further box section 24. Referring to Figure 4, however, the spacing might not be needed if the frame is thinner.

Typically the present invention is fitted in a wall as part of a smoke ventilation system.

The present invention thus also comprises a smoke ventilation system for a building comprising a vent as described above.

The present invention has been described above purely by way of example. Modifications in detail may be made to the invention as defined in the claims appended hereto.

Claims

CLAIMS:

1. An automatic opening vent comprising a metal frame, a door fitted within the frame, and a door opening mechanism for automated opening of the door relative to the frame, wherein the frame has a front-most plane, the door has a front surface and the front surface of the door is substantially co-planar with the front-most plane of the frame when the door is closed.

2. The vent of claim 1, wherein the door has a flat and plain front surface

3. The vent of claim 1 or claim 2, wherein the door opening mechanism is mounted at a rear of the door.

4. The vent of any one of the preceding claims wherein the door opening mechanism is fully concealed from view at the front of the vent while the door is closed.

5. The vent of any one of the preceding claims wherein the frame's front-most plane is defined by a plaster-guide formation.

6. The vent of any one of the preceding claims wherein the frame is formed from four sectional components, two defining sides and two defining a top and bottom of the frame.

7. The vent of any one of the preceding claims wherein the frame’s front-most plane extends frontwards of a sideward extending flange of the frame.

8. The vent of claim 7, wherein the sideward extending flange is perforated, or otherwise roughened, to facilitate grab of plaster thereon upon the installation of the frame within a wall.

9. The vent of any one of the preceding claims wherein the door is made of metal, and infilled with an insulative material.

10. The vent of any one of the preceding claims wherein two opposing parts of the frame have provided therein either pivot pins or pivot holes for pivotal mounting of the door within the frame using suitably positioned pins or holes on the door.

11. The vent of claim 10, wherein at least one pin is moveable to allow the door to be easily fitted and removed.

12. The vent of any one of the preceding claims wherein the door has a fire seal extending around its perimeter.

13. The vent of any one of the preceding claims wherein three inside walls of the frame are flat and a fourth inside wall of the frame instead has a step to act as a doorstop.

14. The vent of any one of the preceding claims wherein the door opens rearwardly.

15. The vent of any one of the preceding claims wherein the frame comprises a first sideward extending flange at a front end thereof and a further sideward extending flange at a rear end thereof to define an approximate U section at that part.

16. The vent of claim 15, wherein the further sideward extending flange is shorter than the first.

17. The vent of any one of the preceding claims wherein the door’s main structure is formed from folded metal sheets.

18. The vent of any one of the preceding claims wherein the front surface of the door is formed from a sheet that is bent rearwardly at both ends to provide edges of the door.

19. The vent of claim 18, wherein a first edge extends rearwardly to define a flat surface thereon on which a fire seal may be fitted, and at a rear end of this first edge, a further flange is provided, extending outwardly, sideways to define a door closure guide to prevent outward opening of the door

20. The vent of claim 190, wherein the door closure guide is fitted with a fire seal.

21. The vent of any one of claims 19 to 20 wherein a second edge of the door extends rearwardly from the front surface and defines a further flat side surface for the door, which may likewise be fitted with a fire seal.

22. The vent of claim 21, wherein the second edge, at its rearmost end, has an inwardly extending flange for attachment of a back plate of the door.

23. The vent of any one of the preceding claims wherein a free end of the door carries the automated door opening mechanism.

24. The vent of any one of the preceding claims wherein the door’s free end comprises a further folded metal component that define a Z shape reinforcement thereat.

25. The vent of claim 24, wherein the further metal component is a folded component with a bottom that can be welded or otherwise attached to a rear of the front surface of the door, and a top that can have its free end attached to an inside of a first edge of the door and a further part of that top being attached to a back plate of the door.

26. The vent of any one of the preceding claims wherein a box section or folded member is attached adjacent a free end of the door to act as a spacer, a mounting flange or a platform for the door opening mechanism.

27. The vent of any one of the preceding claims wherein a motorised mechanism of the door opening mechanism is mounted on the door generally flush with the rear of the frame.

28. The vent of any one of the preceding claims wherein two opposing sides of the door have a ridge extending outwardly thereon for defining a lip.

29. The vent of any one of the preceding claims wherein the door is fitted with a hole at its free end region and its hinge end region for allowing a power cable for the motorised mechanism to be threaded through and into the door near its mounting position and out again at the hinge side thereof.

30. A smoke ventilation system for a building comprising at least one vent of any 5 one of the preceding claims.

31. A method of installing an automatic opening vent in a building as part of a smoke ventilation system, the method comprising providing an automatic opening vent according to any one of claims 1 to 29, fitting it in a wall with a front thereof facing into

10 a room or corridor of the building, and the rear facing a ventilation space of the building, such as a ventilation shaft.

32. The method of claim 31, wherein the vent has plastering guide up to which plaster is applied during the installation, the plastering guide defining the front-most

15 plane of the frame.

Intellectual

Property

Office

Application No: GB1609948.3 Examiner: Mr Tom Simmonds