Smoke hatch

Abstract

The invention relates to a smoke hatch (1) comprising a stand (2) and a lid (7) arranged to cover an outlet opening. An actuator system (6) is provided for opening the lid (7) and a fan is enclosed in the stand (2) for generating a flow from an inlet opening to the outlet opening. To obtain a smoke hatch with improved capabilities to withstand weather conditions, the safety switch system is enclosed by a water-tight protective housing (11) having a cover (18). Electric cables passing through the wall (4) of the stand (2) via cable openings (14) to enter the protective housing (11) are located under a flashing (15) extending outwards from an upper surface (9) of the wall (4) and downwards past the cable openings (14).

Description

BACKGROUND OF THE INVENTION FIELD OF THE INVENTION

[0001] This invention relates to a smoke hatch, and more particularly, to a smoke hatch having a fan.DESCRIPTION OF PRIOR ART

[0002] Previously there is known a smoke hatch comprising a stand with a lid. A fan and an actuator system for opening the lid are provided to the stand. In case of a fire, the actuator system opens the lid, so that the fan can generate a flow from the inside of a building via an inlet to the smoke hatch and further via an outlet to the surroundings.

[0003] A challenge with such a smoke hatch is that the installation site is located outdoors where the weather conditions may be challenging. Due to this the structure of the smoke hatch needs to be designed to prevent water or snow from causing damage to the smoke hatch or to the building.

[0004] In the previously known smoke hatch one particular problem has been water tightness. Due to safety regulations, it is necessary to provide the smoke hatch system with a safety switch system on the outside of the stand, so that service personnel handling maintenance work can prevent the fan and actuators from being activated during maintenance work. To facilitate this, an electric cable needs to pass through a wall of the water-tight stand, so that an inlet in a bottom part of the safety switch system on the outside of the stand can be connected to the fan and to the actuator system located on the inside of the stand. Due to the fact, that the electric cable is very stiff and requires a large bending radius, the lower part of the electric cable will in some installation be located so low, that a water protection layer (or even an insulation layer) protecting the lower part of the smoke hatch and the base surface under the smoke exhaust needs an extra hole to allow the electric cable to pass. This naturally involves the risk of a water leak.

[0005] The cable opening in the stand has in the prior art solution been filled with a sealing compound. However, over time the weather conditions tend to destroy the sealing compound, which may result in a water leak.SUMMARY OF THE INVENTION

[0006] An object of the present invention is to solve the above-mentioned drawback and to provide a smoke hatch with improved capabilities to withstand weather conditions. This object is achieved with a smoke hatch according to independent claim 1.

[0007] When the safety switch system is enclosed by a water-tight housing, the electric cable can pass through a wall of the stand and enter the water protective housing at a location which is protected by a flashing (water protection plate) extending outwards from the wall of the stand at a position above the cable opening. In such a solution the risk of damages, due to water, can be minimized.

[0008] Preferred embodiments of the invention are disclosed in the dependent claims.BRIEF DESCRIPTION OF DRAWINGS

[0009] In the following the present invention will be described in closer detail by way of example and with reference to the attached drawings, in which Figure 1 illustrates a smoke hatch, Figures 2 and 3 illustrate details of the protective housing of the smoke hatch in Figure 1, Figures 4 and 5 illustrates the safety switch system of the smoke hatch in Figure 1, and Figure 6 illustrates the smoke hatch of Figure 1 at an installation site. DESCRIPTION OF AT LEAST ONE EMBODIMENT

[0010] Figure 1 illustrates a smoke hatch 1 with a stand 2 (casing).

[0011] In Figure 1 a lower part of the stand 1 is provided with an inlet 3 which is connected to an inside of a space in a building. In case of a fire in the building, a fan 5 provided in the stand 2 can be used to remove smoke from the building via the inlet opening 3 and passed on further to surroundings via an outlet opening 8. To facilitate this, an actuator system 6 is provided. In case of a fire, the actuator system 6 opens the lid 7 to reveal the outlet opening 8 via which the flow generated by the fan 5 can be passed to the surroundings. In the example of Figure 1 the outlet opening 8 is on all sides surrounded by upper surfaces 9 of the walls 4 of the stand 2.

[0012] A typical installation site of a smoke hatch 1, as illustrated in Figure 1, is on top of a roof of a building. However, the smoke hatch 1 may alternatively be installed on the side of a driveway leading to an underground parking garage, for instance, or at any other outside location in proximity to a space where smoke removal may be needed.

[0013] In order to meet safety regulations, a safety switch system 12 which is accessible from the outside of the stand 2 is required. This safety switch system is a critical component, as as electric supply to the fan is provided via it. If the electric supply fails, efficient extraction of smoke and heat via the smoke hatch 1 is not possible.

[0014] The safety switch system 12 is in the illustrated example enclosed by a water-tight protective housing 11. Maintenance personnel can utilize this safety switch system 12 to control the operation of the fan 5 and of the actuator system 6. More specifically, as the operation of the smoke hatch 1 is typically remotely controlled by a fire safety automation system of a building, smoke detected inside the building may automatically trigger the actuator system 6 to open or close the lid 7 and to activate or deactivate the fan 5. Automatic starting of the fan 5 or automatic closing of the lid 7 may be dangerous if it occurs during maintenance work, in particular, as the actuator system 6 is usually dimensioned to be able to move the lid also when a significant load of snow is located on top of the lid. Consequently, significant forces are involved.

[0015] Figures 2 and 3 illustrate details of the protective housing 11 of the smoke hatch in Figure 1.

[0016] In order to control the operation of the fan 5 and the actuator system 6, at least one electric cable 13 passes through a wall 4 of the stand 2 via at least one cable opening 14. Due to an outdoor installation, the electric supply cable from the building to the smoke hatch 1 is typically provided to the smoke hatch 1 through the roof of the building, for instance, and further via the inside of the stand 2. In Figure 3 cables 13 connecting the safety switch system 12 to the fan 5 and to the actuator system 6 are illustrated to extend along an inner surface of a wall 4 to cable openings 14 via which the cables pass through the wall 4 of the stand and enter the protective housing 11. As can be seen from the figures, installation of cables to extend along outer surfaces of the walls 4 of the stand 2 is not needed.

[0017] In order to obtain a water-tight design, a flashing 15 (water protection plate) has a first section 16 extending outwards from the upper surface 9 of the wall 4 of the stand 2 at a position above the at least one cable opening 14. The flashing 15 continues further as a second section 17 downwards along the wall 4 past the position of the cable opening 14. In the illustrated example, the second section 17 of the flashing also continues further downwards past the protective housing 11. Due to this, the cable opening 14 is located at a position where it is well protected from water. If a sealing mass is provided to the cable opening 14 after the electric cable 13 has been installed, this mass is well protected from UV light and other external weather-related wear and will remain water-tight for a very long time period. The cable opening 14 is also located in the stand 2 at a position corresponding to the protective housing 11, so that the at least one cable 13 exiting the cable opening 14 can directly enter the protective housing 11. This minimizes the length of the cable 13 located outside of the stand 2 and of the water protective housing 11.

[0018] In the illustrated example, the protective housing 11 comprises a cover 18 attached to the protective housing 11 by one or more screws 19 or nuts. Additionally, the protective housing 11 comprises a base frame 20 attached to the wall 4 of the stand 2 via an upper surface of the wall 9, for instance. The base frame 20 is in this example implemented as a plate having attachment points 21, such as counter parts for receiving screws 19 or nuts, for attaching the cover 18 to the base frame 20.

[0019] The flashing 15 extending outwards above the cable opening 14 is provided with an opening 22 in the second section 17 which extends downwards. This opening 22 is dimensioned to have a height and a width slightly smaller than the height and the width of the base frame 20. Due to this, when the base frame 20 is attached to the stand 2, the flashing 15 can be moved into position where devices attached to the base frame 20 protrude through the opening 22, before the flashing 15 is attached to the stand 2. A base frame seal 23 may be provided along edges of the opening 22 on the inner side (the side of the stand) of the flashing 15 to seal the edges of the opening 22 to the outer surface (facing away from the stand) of the base frame 20. Similarly, edges of the cover 18 may be provided with a cover seal 24 to seal the edges of the cover to the outer surface of the second section 17 of the flashing 15. With the parts in this position, attachment of the cover 18 with the screws to the attachment points 21 will clamp the second section 17 of the flashing 15 between the cover 18 and the base frame 20, which results in a water-tight protective housing 11. In some implementations, as illustrated in Figure 5, it may be beneficial to additionally provide sealing washers 37 of EPDM (Ethylene Propylene Diene Monomer rubber), for instance, under the screwheads to obtain a water-tight sealing between the screw heads and the surface of the cover.

[0020] Preferably, flashings 15 are provided on all sides of the stand 2 which are exposed to weather conditions, such as to rain. In the illustrated example, flashings 15 are provided on all sides of the stand 2.

[0021] In the illustrated example, an inner surface of the lid 7 is provided with a seal 25 along all outer edges. This seal is pressed against the first section 16 of each flashing 15 when the lid 7 is closed to cover the outlet opening 8. This efficiently prevents water from entering the stand. In case the flashings are attached via their first sections 16 to the upper surfaces 9 of the walls 4, for instance, the attachment can be implemented by screws or rivets be located on the inner side of the seal 25. At the corners 26 of the stand 2 where the second sections 17 of the flashings 15 meet, the vertical edges of the flashings 15 are attached to each other to prevent water from entering. This may be implemented by arranging the edges to overlap each other and by bending the overlapping sections tightly together.

[0022] In some implementations the protective housing 18 may be implemented in a different way than in the illustrated example. One alternative is to utilize a box-like base frame having a bottom and a flat cover covering an opening of this base frame. However, irrespective of the exact structure of the protective housing, it is preferable to attach the protective housing 11 to the stand 2 via the upper surface 9 of the wall 4. Due to this, the attachment points with screws 27, for instance, can be covered by the first section 16 of the flashing 15. Alternatively or in addition, the attachment points can be located on the inside of the seal 25 provided along the edges of the lid 7 when the lid is closed. This eliminates the risk that water may enter the structure via these screws 27 and the corresponding holes. For this purpose, the upper part of the protective housing 11 is preferably provided with a protrusion 28 protruding outwards from the housing 11 in a direction away from the cover 18 and towards the stand 2. This protrusion 28 is in the illustrated example provided as an integral part of the base frame 20 by bending the upper part of the base frame, though other solutions may be implemented. An additional advantage of using such a protrusion 28 is that the housing 18 may be located at a small distance from the outer surface of the wall 4. Due to this a gap 29 is formed between the protective housing 11 and the outer surface of the wall 4 of the stand, which will be explained in more detail in connection with Figure 6.

[0023] Figures 4 and 5 illustrate the safety switch system of the smoke hatch in Figure 1. Figure 4 illustrates the safety switch system 12 with the cover 18 removed, and Figure 5 illustrates a partial cross-section of the protective housing and of the stand.

[0024] One or more switches are provided to the safety switch system 12. In the illustrated example two switches 30 and 31 are provided to the safety switch system 12. One to control the fan 5 and one to control the actuator system 6. Preferably, by using the switches, maintenance personnel can cut electric supply to the fan and to the actuator system during maintenance work.

[0025] In order to access the switches 30, 31 to change the state of the switches, the cover 18 needs to be removed by opening the screws 19 or nuts. This minimizes the risk that unauthorized persons could easily access the switches to change the state of them, as a tool is required to access the switches. It is also possible to utilize screws with a specific type of head, instead of commonly used screwdrivers. All electrical connections needed for the safety switch system 12 are implemented by wiring and connections located inside the protective housing 11.

[0026] From Figure 5 it can be seen, that the location of the cable opening 14 is such that the cable 13 directly enters the protective housing 11 at a position well protected from water both from above and from the side.

[0027] A gap 29 is present at the lower edges of the flashings 15 between the wall 4 of the stand 2 and the lower section 17 of the flashing. As illustrated in Figure 5, this gap 29 also continues upwards, so that the gap 29 is present also between the protective housing 11 and the wall 4 of the stand.

[0028] As the cable 13 is extends along the inner wall 4, there is no problem in using a large radius for the cable bend required by a stiff cable, and the cable can enter the protective housing 11 without a need to make any additional holes in the water protection layer 34 illustrated in Figure 6.

[0029] Figure 6 illustrates the smoke hatch of Figure 1 at an installation site.

[0030] In Figure 6, the stand 2 of the smoke hatch 1 is mounted on a base surface 36 located under the smoke hatch 1. In praxis, the base surface may be a part of a roof 32 of a building. The stand 2 is via the inlet 3 connected to an inner space in the building, and in case of a fire, an airflow can be generated out of the building via the inlet 3 and the outlet 8 by means of the fan.

[0031] The roof 32 is provided with heat insulation material 33. In order to avoid heat leakages during cold days, also the walls 4 and the lid 7 of the smoke hatch may be provided with heat insulation material 33.

[0032] Additionally, to ensure that the roof structure remains watertight, the roof 32 and the base surface 36 under the smoke hatch is covered by a water protection layer 34. Depending on the installation site, the water protection layer 34 may be a roofing membrane, such as of bitumen or of a PVC felt (Polyvinyl Chloride). To avoid leaks at the installation site of the smoke hatch, this water protection layer 34 continues up along the outer surfaces of the walls 4 on the sides of the stand which are exposed to weather conditions, such as rain. Depending on the installation site, the regulations may require that the water protection layer 34 continues upwards to a height of at least 300 mm.

[0033] In the illustrated example the water protection layer 34 is provided on all walls 4 of the stand 2. As can be seen from Figure 6, the water protection layer 34 continues to a significant height in the gap 29 provided between the walls 4 and the second sections 17 of the flashings. Additionally, the water protection layer may continue still higher into the gap 29 so that the upper edge 35 is located between the part of the gap 29 which is located between the wall 4 and the protective housing 11.

[0034] It is to be understood that the above description and the accompanying figures are only intended to illustrate the present invention. It will be obvious to a person skilled in the art that the invention can be varied and modified without departing from the scope of the invention.

Examples

Embodiment Construction

[0010]Figure 1 illustrates a smoke hatch 1 with a stand 2 (casing).

[0011]In Figure 1 a lower part of the stand 1 is provided with an inlet 3 which is connected to an inside of a space in a building. In case of a fire in the building, a fan 5 provided in the stand 2 can be used to remove smoke from the building via the inlet opening 3 and passed on further to surroundings via an outlet opening 8. To facilitate this, an actuator system 6 is provided. In case of a fire, the actuator system 6 opens the lid 7 to reveal the outlet opening 8 via which the flow generated by the fan 5 can be passed to the surroundings. In the example of Figure 1 the outlet opening 8 is on all sides surrounded by upper surfaces 9 of the walls 4 of the stand 2.

[0012]A typical installation site of a smoke hatch 1, as illustrated in Figure 1, is on top of a roof of a building. However, the smoke hatch 1 may alternatively be installed on the side of a driveway leading to an underground parking garage, for instanc...

BACKGROUND OF THE INVENTION FIELD OF THE INVENTION

[0001] This invention relates to a smoke hatch, and more particularly, to a smoke hatch having a fan.DESCRIPTION OF PRIOR ART

[0002] Previously there is known a smoke hatch comprising a stand with a lid. A fan and an actuator system for opening the lid are provided to the stand. In case of a fire, the actuator system opens the lid, so that the fan can generate a flow from the inside of a building via an inlet to the smoke hatch and further via an outlet to the surroundings.

[0003] A challenge with such a smoke hatch is that the installation site is located outdoors where the weather conditions may be challenging. Due to this the structure of the smoke hatch needs to be designed to prevent water or snow from causing damage to the smoke hatch or to the building.

[0004] In the previously known smoke hatch one particular problem has been water tightness. Due to safety regulations, it is necessary to provide the smoke hatch system with a safety switch system on the outside of the stand, so that service personnel handling maintenance work can prevent the fan and actuators from being activated during maintenance work. To facilitate this, an electric cable needs to pass through a wall of the water-tight stand, so that an inlet in a bottom part of the safety switch system on the outside of the stand can be connected to the fan and to the actuator system located on the inside of the stand. Due to the fact, that the electric cable is very stiff and requires a large bending radius, the lower part of the electric cable will in some installation be located so low, that a water protection layer (or even an insulation layer) protecting the lower part of the smoke hatch and the base surface under the smoke exhaust needs an extra hole to allow the electric cable to pass. This naturally involves the risk of a water leak.

[0005] The cable opening in the stand has in the prior art solution been filled with a sealing compound. However, over time the weather conditions tend to destroy the sealing compound, which may result in a water leak.SUMMARY OF THE INVENTION

[0006] An object of the present invention is to solve the above-mentioned drawback and to provide a smoke hatch with improved capabilities to withstand weather conditions. This object is achieved with a smoke hatch according to independent claim 1.

[0007] When the safety switch system is enclosed by a water-tight housing, the electric cable can pass through a wall of the stand and enter the water protective housing at a location which is protected by a flashing (water protection plate) extending outwards from the wall of the stand at a position above the cable opening. In such a solution the risk of damages, due to water, can be minimized.

[0008] Preferred embodiments of the invention are disclosed in the dependent claims.BRIEF DESCRIPTION OF DRAWINGS

[0009] In the following the present invention will be described in closer detail by way of example and with reference to the attached drawings, in which Figure 1 illustrates a smoke hatch, Figures 2 and 3 illustrate details of the protective housing of the smoke hatch in Figure 1, Figures 4 and 5 illustrates the safety switch system of the smoke hatch in Figure 1, and Figure 6 illustrates the smoke hatch of Figure 1 at an installation site. DESCRIPTION OF AT LEAST ONE EMBODIMENT

[0010] Figure 1 illustrates a smoke hatch 1 with a stand 2 (casing).

[0011] In Figure 1 a lower part of the stand 1 is provided with an inlet 3 which is connected to an inside of a space in a building. In case of a fire in the building, a fan 5 provided in the stand 2 can be used to remove smoke from the building via the inlet opening 3 and passed on further to surroundings via an outlet opening 8. To facilitate this, an actuator system 6 is provided. In case of a fire, the actuator system 6 opens the lid 7 to reveal the outlet opening 8 via which the flow generated by the fan 5 can be passed to the surroundings. In the example of Figure 1 the outlet opening 8 is on all sides surrounded by upper surfaces 9 of the walls 4 of the stand 2.

[0012] A typical installation site of a smoke hatch 1, as illustrated in Figure 1, is on top of a roof of a building. However, the smoke hatch 1 may alternatively be installed on the side of a driveway leading to an underground parking garage, for instance, or at any other outside location in proximity to a space where smoke removal may be needed.

[0013] In order to meet safety regulations, a safety switch system 12 which is accessible from the outside of the stand 2 is required. This safety switch system is a critical component, as as electric supply to the fan is provided via it. If the electric supply fails, efficient extraction of smoke and heat via the smoke hatch 1 is not possible.

[0014] The safety switch system 12 is in the illustrated example enclosed by a water-tight protective housing 11. Maintenance personnel can utilize this safety switch system 12 to control the operation of the fan 5 and of the actuator system 6. More specifically, as the operation of the smoke hatch 1 is typically remotely controlled by a fire safety automation system of a building, smoke detected inside the building may automatically trigger the actuator system 6 to open or close the lid 7 and to activate or deactivate the fan 5. Automatic starting of the fan 5 or automatic closing of the lid 7 may be dangerous if it occurs during maintenance work, in particular, as the actuator system 6 is usually dimensioned to be able to move the lid also when a significant load of snow is located on top of the lid. Consequently, significant forces are involved.

[0015] Figures 2 and 3 illustrate details of the protective housing 11 of the smoke hatch in Figure 1.

[0016] In order to control the operation of the fan 5 and the actuator system 6, at least one electric cable 13 passes through a wall 4 of the stand 2 via at least one cable opening 14. Due to an outdoor installation, the electric supply cable from the building to the smoke hatch 1 is typically provided to the smoke hatch 1 through the roof of the building, for instance, and further via the inside of the stand 2. In Figure 3 cables 13 connecting the safety switch system 12 to the fan 5 and to the actuator system 6 are illustrated to extend along an inner surface of a wall 4 to cable openings 14 via which the cables pass through the wall 4 of the stand and enter the protective housing 11. As can be seen from the figures, installation of cables to extend along outer surfaces of the walls 4 of the stand 2 is not needed.

[0017] In order to obtain a water-tight design, a flashing 15 (water protection plate) has a first section 16 extending outwards from the upper surface 9 of the wall 4 of the stand 2 at a position above the at least one cable opening 14. The flashing 15 continues further as a second section 17 downwards along the wall 4 past the position of the cable opening 14. In the illustrated example, the second section 17 of the flashing also continues further downwards past the protective housing 11. Due to this, the cable opening 14 is located at a position where it is well protected from water. If a sealing mass is provided to the cable opening 14 after the electric cable 13 has been installed, this mass is well protected from UV light and other external weather-related wear and will remain water-tight for a very long time period. The cable opening 14 is also located in the stand 2 at a position corresponding to the protective housing 11, so that the at least one cable 13 exiting the cable opening 14 can directly enter the protective housing 11. This minimizes the length of the cable 13 located outside of the stand 2 and of the water protective housing 11.

[0018] In the illustrated example, the protective housing 11 comprises a cover 18 attached to the protective housing 11 by one or more screws 19 or nuts. Additionally, the protective housing 11 comprises a base frame 20 attached to the wall 4 of the stand 2 via an upper surface of the wall 9, for instance. The base frame 20 is in this example implemented as a plate having attachment points 21, such as counter parts for receiving screws 19 or nuts, for attaching the cover 18 to the base frame 20.

[0019] The flashing 15 extending outwards above the cable opening 14 is provided with an opening 22 in the second section 17 which extends downwards. This opening 22 is dimensioned to have a height and a width slightly smaller than the height and the width of the base frame 20. Due to this, when the base frame 20 is attached to the stand 2, the flashing 15 can be moved into position where devices attached to the base frame 20 protrude through the opening 22, before the flashing 15 is attached to the stand 2. A base frame seal 23 may be provided along edges of the opening 22 on the inner side (the side of the stand) of the flashing 15 to seal the edges of the opening 22 to the outer surface (facing away from the stand) of the base frame 20. Similarly, edges of the cover 18 may be provided with a cover seal 24 to seal the edges of the cover to the outer surface of the second section 17 of the flashing 15. With the parts in this position, attachment of the cover 18 with the screws to the attachment points 21 will clamp the second section 17 of the flashing 15 between the cover 18 and the base frame 20, which results in a water-tight protective housing 11. In some implementations, as illustrated in Figure 5, it may be beneficial to additionally provide sealing washers 37 of EPDM (Ethylene Propylene Diene Monomer rubber), for instance, under the screwheads to obtain a water-tight sealing between the screw heads and the surface of the cover.

[0020] Preferably, flashings 15 are provided on all sides of the stand 2 which are exposed to weather conditions, such as to rain. In the illustrated example, flashings 15 are provided on all sides of the stand 2.

[0021] In the illustrated example, an inner surface of the lid 7 is provided with a seal 25 along all outer edges. This seal is pressed against the first section 16 of each flashing 15 when the lid 7 is closed to cover the outlet opening 8. This efficiently prevents water from entering the stand. In case the flashings are attached via their first sections 16 to the upper surfaces 9 of the walls 4, for instance, the attachment can be implemented by screws or rivets be located on the inner side of the seal 25. At the corners 26 of the stand 2 where the second sections 17 of the flashings 15 meet, the vertical edges of the flashings 15 are attached to each other to prevent water from entering. This may be implemented by arranging the edges to overlap each other and by bending the overlapping sections tightly together.

[0022] In some implementations the protective housing 18 may be implemented in a different way than in the illustrated example. One alternative is to utilize a box-like base frame having a bottom and a flat cover covering an opening of this base frame. However, irrespective of the exact structure of the protective housing, it is preferable to attach the protective housing 11 to the stand 2 via the upper surface 9 of the wall 4. Due to this, the attachment points with screws 27, for instance, can be covered by the first section 16 of the flashing 15. Alternatively or in addition, the attachment points can be located on the inside of the seal 25 provided along the edges of the lid 7 when the lid is closed. This eliminates the risk that water may enter the structure via these screws 27 and the corresponding holes. For this purpose, the upper part of the protective housing 11 is preferably provided with a protrusion 28 protruding outwards from the housing 11 in a direction away from the cover 18 and towards the stand 2. This protrusion 28 is in the illustrated example provided as an integral part of the base frame 20 by bending the upper part of the base frame, though other solutions may be implemented. An additional advantage of using such a protrusion 28 is that the housing 18 may be located at a small distance from the outer surface of the wall 4. Due to this a gap 29 is formed between the protective housing 11 and the outer surface of the wall 4 of the stand, which will be explained in more detail in connection with Figure 6.

[0023] Figures 4 and 5 illustrate the safety switch system of the smoke hatch in Figure 1. Figure 4 illustrates the safety switch system 12 with the cover 18 removed, and Figure 5 illustrates a partial cross-section of the protective housing and of the stand.

[0024] One or more switches are provided to the safety switch system 12. In the illustrated example two switches 30 and 31 are provided to the safety switch system 12. One to control the fan 5 and one to control the actuator system 6. Preferably, by using the switches, maintenance personnel can cut electric supply to the fan and to the actuator system during maintenance work.

[0025] In order to access the switches 30, 31 to change the state of the switches, the cover 18 needs to be removed by opening the screws 19 or nuts. This minimizes the risk that unauthorized persons could easily access the switches to change the state of them, as a tool is required to access the switches. It is also possible to utilize screws with a specific type of head, instead of commonly used screwdrivers. All electrical connections needed for the safety switch system 12 are implemented by wiring and connections located inside the protective housing 11.

[0026] From Figure 5 it can be seen, that the location of the cable opening 14 is such that the cable 13 directly enters the protective housing 11 at a position well protected from water both from above and from the side.

[0027] A gap 29 is present at the lower edges of the flashings 15 between the wall 4 of the stand 2 and the lower section 17 of the flashing. As illustrated in Figure 5, this gap 29 also continues upwards, so that the gap 29 is present also between the protective housing 11 and the wall 4 of the stand.

[0028] As the cable 13 is extends along the inner wall 4, there is no problem in using a large radius for the cable bend required by a stiff cable, and the cable can enter the protective housing 11 without a need to make any additional holes in the water protection layer 34 illustrated in Figure 6.

[0029] Figure 6 illustrates the smoke hatch of Figure 1 at an installation site.

[0030] In Figure 6, the stand 2 of the smoke hatch 1 is mounted on a base surface 36 located under the smoke hatch 1. In praxis, the base surface may be a part of a roof 32 of a building. The stand 2 is via the inlet 3 connected to an inner space in the building, and in case of a fire, an airflow can be generated out of the building via the inlet 3 and the outlet 8 by means of the fan.

[0031] The roof 32 is provided with heat insulation material 33. In order to avoid heat leakages during cold days, also the walls 4 and the lid 7 of the smoke hatch may be provided with heat insulation material 33.

[0032] Additionally, to ensure that the roof structure remains watertight, the roof 32 and the base surface 36 under the smoke hatch is covered by a water protection layer 34. Depending on the installation site, the water protection layer 34 may be a roofing membrane, such as of bitumen or of a PVC felt (Polyvinyl Chloride). To avoid leaks at the installation site of the smoke hatch, this water protection layer 34 continues up along the outer surfaces of the walls 4 on the sides of the stand which are exposed to weather conditions, such as rain. Depending on the installation site, the regulations may require that the water protection layer 34 continues upwards to a height of at least 300 mm.

[0033] In the illustrated example the water protection layer 34 is provided on all walls 4 of the stand 2. As can be seen from Figure 6, the water protection layer 34 continues to a significant height in the gap 29 provided between the walls 4 and the second sections 17 of the flashings. Additionally, the water protection layer may continue still higher into the gap 29 so that the upper edge 35 is located between the part of the gap 29 which is located between the wall 4 and the protective housing 11.

[0034] It is to be understood that the above description and the accompanying figures are only intended to illustrate the present invention. It will be obvious to a person skilled in the art that the invention can be varied and modified without departing from the scope of the invention.

Examples

Embodiment Construction

[0010]Figure 1 illustrates a smoke hatch 1 with a stand 2 (casing).

[0011]In Figure 1 a lower part of the stand 1 is provided with an inlet 3 which is connected to an inside of a space in a building. In case of a fire in the building, a fan 5 provided in the stand 2 can be used to remove smoke from the building via the inlet opening 3 and passed on further to surroundings via an outlet opening 8. To facilitate this, an actuator system 6 is provided. In case of a fire, the actuator system 6 opens the lid 7 to reveal the outlet opening 8 via which the flow generated by the fan 5 can be passed to the surroundings. In the example of Figure 1 the outlet opening 8 is on all sides surrounded by upper surfaces 9 of the walls 4 of the stand 2.

[0012]A typical installation site of a smoke hatch 1, as illustrated in Figure 1, is on top of a roof of a building. However, the smoke hatch 1 may alternatively be installed on the side of a driveway leading to an underground parking garage, for instanc...

Claims

1. Smoke hatch (1) comprising: a stand (2) with an inlet opening (3), an outlet opening (8) and walls (4) having upper surfaces (9) which surround the outlet opening (8), a lid (7) arranged to cover the outlet opening (8), an actuator system (6) for opening the lid (7), a fan (5) enclosed in the stand (2) for generating a flow from the inlet opening (3) to the outlet opening (8), a safety switch system (12) accessible from an outside of the stand (2) for controlling the operation of the fan (5) and the actuator system (6), and at least one electric cable (13) passing through a wall (4) of the stand (2) via at least one cable opening (14) for connecting the safety switch system (12) to the fan (5) and to the actuator system (6), characterized in that the safety switch system (12) is enclosed by a water-tight protective housing (11) having a cover (18), the housing (11) is attached to a wall (4) of the stand in proximity of an upper surface (9) of the wall (4), the at least one electric cable (13) passing through the wall (4) of the stand (2) via the at least one cable opening (14) enters the protective housing (11) in which it is connected to the safety switch system (12), and a flashing (15) extends outwards from the upper surface (9) of the wall (4) at a position above the at least one cable opening (14) and downwards past the at least one cable opening (14).

2. The smoke hatch according to claim 1, wherein the at least one cable opening (14) is provided to the stand (2) at a position corresponding to the position of the protective housing (11) so the at least one cable (13) exiting the at least one cable opening (14) can directly enter the protective housing (11).

3. The smoke hatch according to claim 1 or 2 wherein, flashings (15) are provided on several sides of the stand (2) to surround the outlet opening (8), the flashings (15) have a first section (16) extending outwards from the upper surfaces (9) of the walls (4), and a second section (17) extending downwards along the walls (4) of the stand (2) to provide a gap (29) between the walls (4) and the lower parts of the second sections (17).

4. The smoke hatch according to claim 3, wherein a water protection layer (34) is provided to cover outer surfaces of the walls (4), the water protection layer (34) has an upper edge (35) protruding into the gap (29) between the walls (4) and the lower parts of the second sections (17) of the flashings (15), and the water protection layer (34) continues from the walls (4) to cover a base surface (36) under the smoke hatch (1) on top of which the smoke hatch (1) is mounted.

5. The smoke hatch according to one of claims 1 to 4, wherein an inner surface of the lid (7) is provided with a seal (25) which is pressed against the first section (16) of each flashing (15) when the lid (7) is closed to cover the outlet opening (8).

6. The smoke hatch according to one of claims 1 to 5, wherein heat-insulation material (33) is provided to the walls (4) of the stand (2) and to the lid (7).

7. The smoke hatch according to one of claims 1 to 6, wherein the safety switch system (12) comprises one or more switches (30, 31) enclosed in the protective housing (11) whereby access to the one or more switches (30, 31) requires opening or removal of the cover (18).

8. The smoke hatch according to one of claims 1 to 7, wherein the cover (18) is attached to the protective housing (11) by one or more screws (19) or nuts.

9. The smoke hatch according to claim 8, wherein sealing washers (37) are provided between the cover (18) and the screws (19) or the nuts.

10. The smoke hatch according to one of claims 1 to 9, wherein the protective housing comprises (11) a base frame (18) attached to the wall (4) of the stand (2), the base frame (20) having attachment points (21) to which the cover (18) is attached, the flashing (15) extending outwards above the cable opening (14) is provided with an opening (22) in the second section (17) extending downwards, the opening (22) is dimensioned to have a height and width smaller than the height and width of the base frame (20), the flashing (15) is clamped to provide a fluid-tight configuration between the cover (18) and the base frame (20) in a position, where the edges of the opening (22) on an inner side of the second section (17) via a base frame seal (23) contact an outer surface of the base frame (20), while edges of the cover (18) via a cover seal (24) contact an outer surface of the second section (17).

11. The smoke hatch according to one of claims 1 to 10, wherein an upper part of the housing (11) is provided with a protrusion (28) having a section protruding outwards from the housing (11) in a direction away from the cover (18), and the protective housing (11) is attached to the upper surface (9) of the wall (4) via the protrusion (28) in a position where a gap (29) is formed between the housing (11) and the wall (4).

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