GB2394103A

GB2394103A - Smoke detector with smoke extraction means

Info

Publication number: GB2394103A
Application number: GB0223441A
Authority: GB
Inventors: Stephen Andrew Thorne
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-10-09
Filing date: 2002-10-09
Publication date: 2004-04-14
Also published as: GB0223441D0

Abstract

A smoke detector 2 comprising means for detecting the presence of smoke, means for generating an audio and/or visual signal in response to the detection of smoke, and extraction means 12 for extracting the smoke. The smoke is preferably extracted from a first 8 to a second 10 region where the detector housing 4 is mounted on a surface 6 between the two regions. The system may include means for generating a further signal at a remote location (20). The system preferably also includes a further one or more smoke detection means (18) mounted at remote locations and each capable of raising an alarm both locally and remotely.

Description

l 2394 1 03

-1 SMOKE DETECTORS

The present invention relates to smoke detectors.

5 Most smoke detectors incorporate a device capable of raising an alarm signal in response to the detection of smoke. In the event of a house fire it is essential that the alarm is raised as early as possible in order to give the occupants sufficient time to evacuate the premises. This is particularly so when the fire breaks out at night when the occupants are asleep, since the alarm must first awaken the occupants. Conventional 10 smoke detectors suffer from the disadvantage that the alarm is raised locally and has a relatively short range. Furthermore, the most common cause of death in house fires is smoke inhalation. Not only does smoke pose a risk of death but it also impedes the evacuation of the building due to reduced visibility.

15 It is an object of the present invention to provide a smoke detector which alleviates at least some of the problems of conventional smoke detectors.

According to a first aspect of the present invention there is provided a smoke detector comprising means for detecting the presence of smoke, means for generating a signal 20 in response to the detection of smoke and extraction means, wherein the extraction means operates in response to the signal generated upon detection of smoke.

The extraction means preferably directs smoke from a first region to a second region.

25 The smoke detector may be mounted on a surface such that the first region lies on one side of the surface and the second region lies on the opposite side of the surface. The surface may suitably be a wall or ceiling of a house. When the smoke detector is arranged as described, smoke can be directed away from areas of the house in which it poses a threat to life. For example, it may be mounted in the ceiling of a hallway to 30 extract smoke from the hallway and into a roof space. This may give occupants extra time to evacuate the building.

-2 It is preferred that the smoke detector comprises a housing, the first region being on one side of the side of the housing and the second region being on an opposite side of the housing, the two regions being in communication such that, in use, smoke is directed through the housing from the first region to the second region.

Preferably, communication between the first and second regions is controlled on the basis of the signal generated upon the detection of smoke. Vents may be provided in the housing which are closed when no smoke is present and which upon in response to the signal generator upon the detection of smoke. This ensures that when the smoke 10 detector is mounted in a ceiling of a house, for example, that no heat is lost through the smoke detector when no smoke is present.

The smoke detector may suitably be mains operated.

I S Preferably, the smoke detector further comprises alarm means responsive to the signal generated by the detection of smoke. The alarm means may suitably comprise an audible alarm signal and/or a visual alarm signal. In addition, the alarm means may also comprise means for generating a further alarm signal, at a remote location. The further alarm signal may suitably comprise an audible alarm signal and/or a visual alarm signal.

20 A smoke detector having means for generating a further alarm signal at a remote location has the advantage that it increases the chances of occupants being alerted to a fire at an early stage and thus provides more time for evacuation. The smoke detector may be in radio communication with the means for generating a further alarm signal or they may be wired together.

The means for generating a further alarm signal may be mains operated.

According to a second aspect of the present invention, there is provided a smoke detection system comprising at least one smoke detector as described above, at least one 30 further smoke defector haying means for defecting smoke and means generating a signal in response to the detection of smoke and at least one remote alarm wherein an alarm signal is raised at the or each remote alarm in response to a signal generated at any one of the first mentioned or further smoke detectors.

Reference will now be made to the accompanying drawings showing, solely by way of example, one embodiment of the present invention in which: Fig. 1 shows a side view of a smoke detector mounted in a surface in a first state.

Fig. 2 shows a side view of the smoke detector of Fig. 1 in a second state.

Fig. 3 is a schematic view of one floor of a house with a smoke detector system.

10 Fig. 4 is a schematic view of another floor of the house of Fig. 3.

Referring now to Figs. 1 and 2, these show a smoke detector 2 contained within a housing 4 and mounted on a surface 6. The surface 6 may be an internal surface of a house, for example, a wall or ceiling and the smoke detector 2 may conveniently be 15 mounted by a screw fix between the housing and the surface 6. Alternatively, the smoke detector 2 may be fitted into an opening cut in the surface 6 for receiving the smoke detector 2. In a particularly preferred embodiment the smoke detector 2 may be mounted on the entrance hatch to a loft space. A first region 8 lies on one side of the smoke detector 2 and a second region 10 lies on an opposite side ofthe smoke detector 2. In 20 the case where the smoke detector 2 is mounted on a loft hatch in the ceiling, the first region 8 will be in the interior of the house, for example a hallway, and the second region 10 will be a loft or roof space which will generally be uninhabited. Alternatively, the smoke detector 2 may be mounted on a wall in which the first region 8 is an internal region and the second region 10 is external to the house.

Within the housing 4 there is provided means for detecting the presence of smoke (not shown). The means for detecting the presence of smoke may take the form of a photoelectric detector or an ionisation detector or any other suitable detection means.

When the presence of smoke is detected a signal is generated. Also located within the 30 housing 4 is an extraction means (not shown) which operates in response to the signal generated by the means for detecting the presence of smoke. The extraction means may suitably be in the form of an extraction fan and in use will direct the flow of air and hence smoke, from the first region 8 to the second region 10. The extraction fan must

-4 be powerful enough to extract a large volume of smoke in a short period of time. With a smoke detector 2 fitted on a loft hatch as described, the first region 8 will normally be a hallway. The size of the hallway will vary from house to house but it can be seen that in order to clear the exit route for occupants the extraction fan must be powerful enough 5 to remove a sufficient quantity of smoke such that visibility is improved.

It is therefore advantageous to have the smoke detector 2 mains operated. This will enable a more powerful extraction fan to be fitted than would be the case with a battery operated smoke detector. In addition, it will overcome one problem, associated with 10 many conventional smoke detectors in that users often neglect to replace the battery with the result that the detector does not function.

The extraction means is provided to direct smoke from a first region 8 to a second region 10 which will normally be a safe zone. The path of the smoke is through a 15 passageway (not shown) in the housing 4. Since it would be undesirable for domestic use to have the passageway constantly open, means is provided for controlling communication between the first region 8 and the second region 10. The smoke detector 2 is provided with flaps 12 (shown in Fig. 2) which are moveable from a first position as seen in Fig. 1, in which the passageway is closed to a second position, as seen in Fig. 20 2, in which the passageway is open to allow the flow of smoke. The movement of the flaps from the first to the second position is controlled in response to the signal generated upon detection of smoke.

When smoke is detected in the vicinity of the smoke detector 2 a signal is generated 25 which controls the operation of the extraction fan and the opening of the flaps 12. The smoke detector 2 is also provided with alarm means (not shown) such that an audible and/or visual alarm signal is produced upon detection of smoke. However, it is often the case in house fires that the alarm signal is raised in one location, for example, outside the kitchen, yet it is not detected by the occupants who may be in another 30 location, for example the bedroom. This is particularly the case at night when the occupants are in bed and may not be awaken by a distant alarm. In house fires it is vitally important to alert occupants and evacuate the premises as soon as possible.

-5 Consequently, the smoke detector 2 of the present invention is provided with means for generating a further alarm signal at one or more remote locations. The further alarm signal may be an audible, visual or other alerting signal and may be generated in alarm units at a variety of locations. At its most basic the smoke detector 2 is provided with 5 one alarm unit (shown in Figs. 3 and 4) capable of generating a further alarm signal.

Preferably this unit is located in a prominent location, for example at a bedside. This will provide an early warning system which may provide valuable extra minutes to evacuate the premises. In a further embodiment the smoke detector 2 may be provided with a plurality of alarm units which may be located throughout the house. The alarm 10 units may be incorporated into household items such as a clock radio. The alarm units may also be incorporated into cellular phone handsets such that a user may be alerted to the presence of smoke even when not at home. The smoke detector 2 may be in radio communication with the or each alarm unit such that a radio signal is sent to the alarm unit upon detection of smoke. Alternatively, the smoke detector 2 may be hard wired, 15 to the or each alarm unit or, in the case of the cellular phone unit, the smoke detector may be provided with a suitable transmitter.

Referring now to Figs. 3 and 4, these show a schematic layout 14 of a typical home with one embodiment of a smoke detection system according to the present invention. The 20 smoke detection system employs the combination of at least one smoke detector 2 having an extraction fan as shown in Figs. l and 2, at least one conventional smoke detector 18 having means for detecting smoke and means for generating a signal in response to the detection of smoke and at least one remote alarm unit 20. Fig. 3 shows the ground floor of a house having a conventional smoke detector 18 fitted in each of 25 the three rooms. Fig. 4 shows the upper floor of the house shown in Fig. 3. The upper floor has a smoke detector 2 as shown in Figs. l and 2 and described above and a remote alarm unit 20 located in the master bedroom. If smoke is detected at any of the smoke detectors 2, 18 a signal is generated which raises an alarm locally and at the remote location 20. This has the benefit that an alarm will be raised in the bedroom upon 30 detection of smoke in the kitchen or another location distant from the bedroom at which a traditional "local" smoke may not be heard. This is particularly useful at night since the alarm in the kitchen may not be sufficient to awaken occupants asleep upstairs. In addition to raising an alarm at the remote location 20, all the smoke detectors 2, 18 are

-6 connected such that the detection of smoke at one location raises an alarm at all locations. The smoke detectors 2, 18 and remote alarm 20 may be in radio communication or may be wired together.

5 A further feature of the smoke detection system is the provision of a display on the or each remote alarm unit 20 which can display the location of the smoke detector 2, 18 which has raised the alarm. This will enable the occupants to select the most appropriate evacuation route.

Claims

1. A smoke detector comprising means for detecting the presence of smoke, means for generating a signal in response to the detection of smoke and extraction 5 means, wherein the extraction means operates in response to the signal generated upon detection of smoke.

2. A smoke detector according to claim l, wherein the extraction means is provided to direct smoke from a first region to a second region.

3. A smoke detector according to claim 2, wherein the smoke detector is mountable on a surface such that the first region lies on one side of the surface and the second region lies on the opposite side of the surface.

15

4. A smoke detector according to claim 2 or claim 3, wherein the smoke detector comprises a housing, the first region being on one side ofthe side ofthe housing and the second region being on an opposite side of the housing, the two regions being in communication such that, in use, smoke is directed through the housing from the first region to the second region.

5. A smoke detector according to claim 4, wherein communication between the first and second regions is controlled on the basis of the signal generated upon the detection of smoke.

25

6. A smoke detector according to any preceding claim, wherein the smoke detector is mains operated.

7. A smoke detector according to any preceding claim further comprising alarm means responsive to the signal generated by the detection of smoke.

8. A smoke detector according to claim 7, wherein the alarm means comprises an audible alarm signal.

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9. A smoke detector according to claim 7 or claim 8, wherein the alarm means comprises a visual alarm signal.

10. A smoke detector according to any one of claims 7-9, wherein the alarm 5 means comprises means for generating a further alarm signal, at a remote location.

11. A smoke detector according to claim l O. wherein the further alarm signal generated at the remote location is an audible alarm signal.

10

12. A smoke detector according to claim lO or claim l l, wherein the further alarm signal generated at the remote location is a visual alarm signal.

13. A smoke detector according to any one of claims 10-12, wherein the smoke detector is in radio communication with the means for generating a further alarm signal.

14. A smoke detector according to any one of claims 10-13, wherein the means for generating a further alarm signal is mains operated.

15. A smoke detection system comprising at least one smoke detector according 20 to any one of claims 1-14, at least one further smoke detector having means for detecting smoke and means generating a signal in response to the detection of smoke and at least one remote alarm wherein an alarm signal is raised at the or each remote alarm in response to a signal generated at any one of the first mentioned or further smoke detectors.

16. A smoke detector substantially as hereinbefore described with reference to the accompanying drawings.

17. A smoke detection system substantially as hereinbefore described with 30 reference to the accompanying drawings.