GB2128789A - Intruder alarm system and method of installing same - Google Patents

Abstract

An intruder alarm system, and method of installing same, comprising sound generating means (1), sound emitting means (11, 12) remote from the sound generating means (1) and means (10) connecting the sound generating means (1) to the sound emitting means (11, 12) so that when the sound generating means (1) is actuated sound will be emitted by the sound emitting means (11, 12). The "sound generating means" may be a source of air under pressure and the sound emitting means may generate the sound. <IMAGE>

Description

SPECIFICATION Intruder alarm system and method of installing same Intruder alarm systems installed in buildings or premises such as dwelling houses, shops, offices, factories, or the like generally comprise a bell or other audible warning means which is mounted on an external wall of the building or premises. Such externally mounted audible warning means usually incorporate a power source such as a battery or batteries and a printed circuit board so that it cannot be rendered inoperative simply by isolating it from a mains supply.Intruder, alarm systems comprising an externally mounted audible warning means suffer from the disadvantages that, even though the audible warning means is usually mounted within a suitable housing and is expected to meet the requirements of British Standard BS4737 as regards suitability for use under a wide range of temperatures and other environmental conditions, it is exposed to the elements and is subject to deterioration and malfunctions such as false alarms from failure or deterioration of the power source or printed circuit board. Being externally mounted, the audible warning means is open to view and is thus easily located.Even if at least one false or "dummy" audible warning means is provided as well as the genuine article the "dummy" means is frequently distinguishable from the genuine or "active" means because it does not incorporate a xenon bea.con or like visible warning means. Moreover, the "active" audible warning means is frequently accessible, e.g., by use of a ladder, and inadequately secured and thus can be quickly rendered inoperative by a determined burglar in a number of different ways, such as by first removing the housing and then rendering the audible warning means inoperative as by removing the batteries or other power source, by injecting a plastics or other foam into the housing or by simply forcibly removing the audible warning means from the wall on which it is mounted and then rendering the audible warning means inoperative either by force or by immersing it in water.

Further, externally mounted audible warning means are expensive to fit and maintain in terms of labour and the fitting and maintenance thereof usually involves ladderworkwith its attendent hazards.

The present invention has as its object to provide an intruder alarm system, and a method of installing same, which overcomes or mitigates the aforesaid disadvantages, which is easier and cheaper to install and maintain, and which is applicable to both new and existing intruder alarm systems.

The present invention provides an intruder alarm system comprising sound generating means, sound emitting means remote from said sound generating means, and means connecting said sound generating means to said sound emitting means so that when the sound generating means is actuated sound will be emitted by the sound emitting means.

The present invention also provides a method of installing an intruder alarm system in a building comprising the steps of installing sound generating means within the building, providing sound emitting means at one or more locations remote from the sound generating means, and connecting said sound generating means to said sound emitting means so that when the sound generating means is actuated sound will be emitted by the sound emitting means.

Preferably said sound generating means is provided at a concealed location within the building and/or is provided within the building at a location which is difficult of access whilst the sound emitting means is located to emit sound externally of the building. For example, the sound generating means may be located in an attic or loft space of a building, e.g., may be mounted between the ceiling joists in the attic or loft space and concealed beneath any heat insulating material, such as a glass fibre blanket, of the kind now commonly installed in attic or loft spaces. Alternatively, the sound generating means can be installed beneath floorboards or some other such concealed location or may be mounted high on a wall or ceiling, e.g., above a stair well, so as to be difficult of access.Said sound emitting means is preferably provided at one or more locations, preferably concealed locations, where the sound will be heard outside the building or premises, for example a concealed location such as ventilation space beneath the eaves of a dwelling house or a location behind an air brick in an external wall of the building or premises. Alternatively, the sound emitting means may be mounted externally of the building, e.g., within a suitable housing mounted on an external wall of the building. If desired at least one sound emitting means may be provided at a location within the building or premises.

According to a first embodiment of the present invention the sound generating means comprises sound producing means such as an air horn or electronic sound producing means of the kind usually known as electronic sounders. The connecting means in this embodiment comprises passage means, e.g., provided by suitable conduit or tubing of plastics or other suitable material, for transmitting sound from the sound generating means to the sound emitting means. In this embodiment the sound emitting means may simply comprise an open end or open ends of the passage means.

Where sound emitting means is to be provided at more than one location, e.g., at both the front and back of a building or premises, then said passage means may comprise branches which terminate in an open end at each desired location of sound emitting means. Thus the sound generating means of the alarm system of the present invention may comprise one or more air horns or electronic sounders adapted to produce a sound or sounds of a pitch and/or volume such that when transmitted through said passage means the sound emitted will be sufficiently loud and of such a nature as to be likely to both attract attention of passers-by or others and to unnerve an intruder or intruders. If desired or necessary a plurality of air horns or electronic sounders can be provided the sound outlets of which are connected into said passage means.

According to a second embodiment of the present invention the sound generating means comprises activating means whilst the sound emitting means comprises sound producing means actuatable by the activating means. Thus, for example, the activating means may comprise a source of air or gas under pressure such as an electrically operated pump or compressor or a compressed air or gas cylinder which is connected by way of passage means such as suitable conduit or tubing to sound emitting means in the form of an air horn or other air or gas operated sound producing means. Alternatively, the activating means may comprise suitable activating electric circuit means connected by suitable electrical wiring to sound emitting means in the form of electrically operated sound producing means such as an electric alarm bell.

The alarm system may comprise a plurality of sound producing means mounted externally of the building or premises and a single activating means mounted internally of the building or premises to which each ofthe sound producing means is connected. In addition one or more sound producing means may be mounted internally of the building or premises and may also be connected to said single activating means. The activating means may include means for actuating the sound producing means in the event that any one of the sound producing means is tampered with e.g., is forcibly removed.

The activating means preferably includes timer means for automatically switching-off the sound producing means a predetermined period of time after the sound producing means has been actuated to prevent the sound producing means sound indefinitely.

Most intruder alarm systems incorporate what is known as an entry/exit tone which sounds when a person enters or leaves the building or premises in which the alarm system is installed to indicate to a user that the alarm system is in operation. On entry, if at the end of said short period of time during which the entry tone sounds, the alarm system has not been switched off using a special key then the alarm will sound. Said entry/exit tone may be provided by said sound producing means, to which end the sound producing means may be adapted to provide two tones, i.e., an entry/exit tone and an alarm tone or sound. In order that the entry/exit tone will he heard within the building or premises said passage means of said first embodiment may have at least one branch which terminates within the building or premises.Preferably said at least one branch has at least one bend provided therein and/or is of such a length that even if an intruder manages to locate the outlet end of said branch from which the sound is issuing, he will not be able to render the sound producing means inoperative as by inserting a long object such as a knitting needle into the outlet end of the branch. According to said second embodiment sound producing means is provided internally of the building to provide the entry/exit tone.

The alarm system of the present invention may include at least one detection device of a kind well known in the art, e.g., at least one set of electric contacts on a door or window which will be activated if the door or window is opened, at least one pressure-pad which will be activated if a person steps thereon, at least one light source and photocell arrangement which will be activated if the beam of light is interrupted, at least one sonic or acoustic detector, at least one movement or proximity detector, or the like, or any combination thereof.

If desired the alarm system of the present invention may further comprise at least one visual alarm means such as a xenon beam which will be activated with the audible alarm. Such visual alarm means is preferably provided internally of the building or premises in a location where it will be visible from outside the building or premises, e.g., mounted on a ceiling just inside an upstairs window of a dwelling house so as to be visible through said window when activated.

The invention will be more particularly described with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a block diagram of an alarm system according to one embodiment of the present invention Figure 2, 3 and 4 illustrate these further embodiments of the invention, and Figure 5 is a block diagram of yet another embodiment of the invention installed in a dwelling house.

Referring to Figure 1 of the drawings it will be seen that the intruder alarm system illustrated therein comprises sound generating means in the form of an electronic sounder 1, a self-activating alarm module 2 and an automatic shut-off module 2a each of a kind well known in the art, and an electric battery or batteries 3 all of which are mounted in a box or housing 4 adapted to be mounted between the joists in an attic or loft or beneath a floor of a building such as a dwelling house, at least one visual alarm means 5 such as a xenon beacon, at least one detecting device 6, such as a set of electrical contacts mounted on a door or window, a pressure pad, electron beam or sonic detector, or the like, and a control unit 7 of a kind well known in the art.The control unit 7 is connectable to a source of mains electricity 8 and may also incorporate a battery or batteries for use in the event of failure or interruption of the mains supply, and is electrically connected with the at least one detection device 6, the at least one visual alarm means 5, the self-activating alarm module 2 and the electronic sound generating means 1, in known manner. The electric battery or batteries 3 serve to provide power to the self-activating alarm module 2, the automatic shut-off module 2a and the electronic sound generating means 1, e.g., in the event of a failure or interruption in the mains electricity supply or the supply from the control unit 7. The automatic shut-off module 2a is adapted to switch-off the sound generating means 1 after a predetermined period of time if this has been activated and for any reason cannot be switched off by a keyholder in the usual way from the control unit 7, e.g., due to all connections between the control unit and the sound generating means having been severed by an intruder. Connected to the sound outlet 9 of the electronic sound generating means lisa passage means 10 for transmitting sound from the sound generating means 1 to sound emitting means in the form of sound outlet orifices 11 and 12 remote from the sound generating means 1. The passage means 10 is provided by plastics or other suitable tubing, e.g., having an internal diameter of about 38mm (1.5 inches).Preferably, the outlet orifice 11 is provided internally of the building or premises in which the alarm system is fitted whilst the outlet orifice 12 is in a concealed location such that the sound will be transmitted to the exterior of the building or premises. Thus the outlet orifice 12 may be located in a ventilation space provided under the eaves of a dwelling house or behind an air brick in an external wall of the building or premises so that in the event thatthe alarm is activated it will not be immediately apparent exactly where the sound is issuing from.

Alternatively, the outlet orifice 12 could be located within an externally mounted housing similar to that used to house a conventional alarm bell so that the system of the present invention has the appearance of a conventional system at least from the outside of the building or premises in which the system is installed. Said externally mounted housing and/or the housing 4 may be such as to comply with British Standard 4737.

It will readily be apparent to those skilled in the art that because the sound generating means 1 is located within the building or premises to which the alarm system is fitted, it is not subject to the elements as is the conventional externally mounted alarm bell and is accordingly not so subject to deterioration and malfunctioning.

Moreover, because the sound generating means is mounted within the building and can be mounted in a concealed location such as in a loft or attic beneath loft insulation or beneath floor boards, it Is less likely to be quickly found and rendered inoperative. The sound orifices 11 and 12, being simply the open ends of tubing, are less apparent to an intended intruder, give no clue as to the location of the sound generating means 1, and even if blocked or plugged or otherwise tampered with will not prevent the alarm being sounded. Indeed, if a plurality of sound orifices 11 and/or 12 are provided and one is blocked or plugged then the sound issuing from the remaining outlet or outlets will increase.Further, electronic sound generating means 1 are available which have lower power requirements than the standard exter nally mounted 152mm (6 inch) alarm bell conventionally used, thus enabling greater flexibility in the design of the alarm system, e.g., allowing the storage capacity of the batteries 3 to be reduced, the associated power supply unit outputs to be decreased or the number of detection devices 6 to be increased. Where rechargeable batteries are used the recharging time from flat can also be improved.

It will also be appreciated that the passage means 10 is simple to install using commercially available plastics tubing and fittings such as are used in plumbing and that the passage means 10 can be concealed in a loft or attic or beneath floorboards so as not to detract from the decoration and furnishings in a building or premises to which the alarm system is fitted.

In the embodiment of Figure 2 the sound generating means comprises an electrically operated pump or compressor 20 and an air horn 21 connected to the pump or compressor 20 by flexible conduit 22 whilst the sound emitting means comprises internal and external sound orifices 23, 24 respectively of tubing 25 connected to the air horn 21 so as to transmit the sound therefrom.

The embodiment of Figure 3 is similar to the embodiment of Figure 2 and like parts have been given like reference numerals. However, in the embodiment of Figure 3 the sound emitting means comprises the air horn 21.

The embodiment of Figure 4 is again similar to the embodiment of Figure 2 and again like reference numerals have been used for like parts. The difference in Figure 4 is that in place of the air horn 21 the conduit 22 has one or more loops 26 therein so that it will produce sound in the manner of a musical wind instrument such as a trumpet.

In each of the embodiments of Figures 1 to 4 the arrangement is such that the sound generating means, e.g., the electronic sounder 1 or the pump or compressor 20, will operate even if the normal source of power, e.g., from the control box 7, is interrupted. This can be achieved by the use of self-activating circuitry and a suitable battery or batteries to supply power or by the use of suitable relays and a separate mains supply of electricity.

Referring now to Figure 5 of the drawings it will be seen that the intruder alarm system illustrated therein comprises a plurality of sound emitting means 31 mounted externally of the house 32 on external walls 32a, 32h, e.g., at the front and rear of the house 32 respectively, activating means 33 comprising a self-activating alarm module 33a and an automatic shut-off module 33b each of a kind well known in the art, and an electric battery or batteries 33c all of which are mounted in a box or housing 34 adapted to be mounted internally of the building remote from the sound emitting means 31, e.g., between the joists in an attic or loft 35, or beneath a floor of the house 32, at least one visual alarm means 36 such as a xenon beacon mounted either internally where it can be seen through a window or externally, at least one detection device 37, such as a set of electrical contacts mounted on a door or window, a pressure pad, electron beam or sonic detector, or the like, an internal sound generating means 42, e.g., for providing an internal alarm and/or an entry/exit tone, and a control unit 38 of a kind well known in the art. The control unit 38 is connectable to a source of mains electricity 39 and may also incorporate a battery or batteries for use in the event of failure or interruption of the mains supply, and is electrically connected with the at least one detection device 37, the at least one visual alarm means 36, the activating means 33 and the sound emitting means 31, in known manner. The electric battery or batteries 33c serve as a secondary power source to provide power to the self-activating alarm module 33a, the automatic shut-off module 33b and the sound emitting means 31, e.g., in the event of a failure or interruption in the primary power supply such as the mains electricity supply and the supply from the control unit 38. The automatic shut-off module 33b is adapted to switch-off the sound emitting means 31 after a predetermined period of time if this has been activated and for any reason cannot be switched off by a keyholder in the usual way from the control unit 38, e.g., due to all connections between the control unit and the sound generating means having been severed by an intruder. Each of the sound emitting means 31 comprises an electrically operated bell or other sound emitter 40 mounted in a housing 41. The housing 41 may accord with British Standard 4737.

It will readily be apparent to those skilied in the art that because the activating means 33 is located within the building or premises to which the alarm system is fitted, it is not subject to the elements as is the conventional externally mounted self-activated alarm bell and is accordingly not so subject to deterioration and malfunctioning. Moreover, because the activating means is mounted within the building and can be mounted in a concealed location such as in a loft or attic beneath a loft insulation or beneath floorboards, it is less likely to be quickly found and rendered inoperative. The fact that a single activating means 33 can serve a plurality of sound emitting means 31 reduces costs, simplifies the wiring of the system and assists maintenance of the system.

Claims (19)

1. An intruder alarm system comprising sound generating means, sound emitting means remote from said sound generating means, and means connecting said sound generating means to said sound emitting means so that when the sound generating means is actuated sound will be emitted by the sound emitting means.

2. An intruder alarm system according to claim 1, wherein the sound generating means is provided at a location within a building which is concealed and/or difficult of access.

3. An intruder alarm system according to claim 1 or 2, wherein the sound emitting means is provided at a location to emit sound externally of a building.

4. An intruder alarm system according to claim 3, wherein said sound emitting means is provided at a concealed location.

5. An intruder alarm system according to any one of the preceding claims, wherein the sound generating means comprises sound producing means said connecting means comprises passage means for transmitting sound from the sound generating means and the sound emitting means comprises an outlet end or ends of the passage means.

6. An intruder alarm system according to claim 5, wherein the sound producing means comprises an air horn or an electronic sounder.

7. An intruder alarm system according to claim 5 or 6, wherein the passage means comprises tube or conduit.

8. An intruder alarm system according to any one of claims 1 to 4, wherein the sound generating means comprises sound activating means and the sound emitting means comprises sound producing means.

9. An intruder alarm system according to claim 8, wherein the sound activity means comprises a source of gas or air under pressure, the sound producing means comprises an air horn or air or gas operated sound producing means and the connecting means comprises passage means.

10. An intruder alarm system according to claim 9, wherein said passage means comprises tube or conduit.

11. An intruder alarm system according to claim 7 or 10, wherein said tube or conduit is of flexible plastics material.

12. An intruder alarm system according to claim 8, wherein said sound activating means comprises activating electric circuit means, said sound emitting means comprises electrically operated sound producing means and the connecting means comprises electric wiring.

13. An intruder alarm system according to any one of the preceding claims, including means inter nally of the building for emitting sound.

14. An intruder alarm system according to claim 13, wherein said internal sound emitting means is adapted to produce an entry/exit tone.

15. An intruder alarm system according to any one of the preceding claims, comprises at least one detection device.

16. An intruder alarm system according to any one of the preceding claims, comprising at least one visual alarm means.

17. An intruder alarm system substantially as herein described with reference to Figure 1, Figure 2, Figure 3, Figure 4 or Figure 5 of the accompanying drawings.

18. A method of installing an intruder alarm system in a building comprising the steps of installing sound generating means within the building, providing sound emitting means at one or more locations remote from the sound generating means, and connecting said sound generating means to said sound emitting means so that when the sound generating means is actuated sound will be emitted by the sound emitting means.

19. A method of installing an intruder alarm system in a building, substantially as herein described with reference to Figure 1, Figure 2, Figure 3, Figure 4 or Figure 5 of the accompanying drawings.