GB2381967A

GB2381967A - Fire protection at electrical plug and socket

Info

Publication number: GB2381967A
Application number: GB0215043A
Authority: GB
Inventors: Michael Charles Fileman
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-06-28
Filing date: 2002-06-28
Publication date: 2003-05-14
Also published as: GB0215043D0; GB0115880D0

Abstract

Apparatus for use in indicating a fire or fire inducing condition, e.g. a spark, in the vicinity of an electrical plug and socket comprises a housing which is configured so that it can locate over a plug and socket connection on the wall of a building. The housing accommodates heat sensing means which can sense a fire inducing condition and activate means for issuing a warning signal in response. The warning can be visible, audible or both. Alternatively, in response to the sensed fire inducing condition, fire retardant material, such as fire extinguishing powder, may be released from inside the housing to extinguish any fire which may have been generated.

Description

FIRE PROTECTION This invention relates to the prevention of fires and in particular relates to an apparatus that can be used in conjunction with a conventional electrical plug and socket in order to prevent the occurrence of fires at such locations.

The vast majority of electrical appliances used in buildings are connected to a source of mains electricity by means of a plug which locates in a socket provided in a face plate normally mounted on a wall of that building. In many instances such plugs remain engaged in their associated sockets for long periods and are not removed on a regular basis. This may be because the sockets themselves are relatively inaccessible, eg. behind television or other electrical appliances. It is not uncommon for faults to occur in the plug/socket combination and this can lead to the generation of sparks. If the spark occurs in the vicinity of inflammable material such as the material of a curtain or furniture then this represents a significant fire hazard.

The present invention has been designed in order to alleviate this problem.

According to a first aspect of the present invention there is provided an apparatus for use in indicating a fire or a fire inducing condition in the vicinity

of an electrical plug and socket comprising a housing which is configured so that it can be held in position over a plug socket connection when the plug is located in the socket, and heat sensing means associated with the housing for issuing a warning signal in response to the sensing of a fire inducing condition.

The warning signal may be visible, audible or both.

The housing may include aU-shaped rear part arranged to locate behind an electrical socket and a cover pivotally connected to the rear part. The housing may be made from flame retardant plastic.

According to the present invention there is provided apparatus for use in preventing or extinguishing a fire at or in the vicinity of an electrical plug and socket connection comprising a housing which is configured so that it can be held in position over the plug socket connection when the plug is located in the socket, a fire retardant material releasably secured in said housing, and an actuating means operable in response to the sensing of a fire inducing condition to cause the release of said fire retardant material to the interior of the housing.

The actuating means may comprise a heat sensor and an associated micro switch which is operable when the heat sensor senses a fire inducing condition

to cause the release of the fire retardant material.

The fire retardant material may comprise a conventional fire extinguishing powder.

The apparatus may be designed for use with either single or multi-plug sockets.

The invention will be described now by way of example only with particular reference to the accompanying drawings. In the drawings: Figure 1 is a perspective view of an apparatus in accordance with an embodiment of the present invention.

Figure 2 is a view similar to Figure 1 showing the front wall of the apparatus in an open condition.

Figure 3 is an illustration showing the configuration of the rear wall of the housing.

Figures 4-6 show one example of how a fire retardant material may be mounted in the housing.

Figure 7 is a perspective view of another embodiment of apparatus in accordance with the present invention.

Figure 8 is a similar perspective view showing a plug in position.

Figure 9 is a side elevation of the apparatus of Figure 7.

Figure 10 is a perspective view of the apparatus and attachment and Figure 11 is a perspective view of the apparatus fitted with an alarm.

Referring to the drawings apparatus for use in preventing or extinguishing the fire at or in the vicinity of the electrical plug and socket connection comprises a housing 10 which has rectangular front and rear walls 11 and 12, a rectangular top wall 14, end walls 15 and 16 and a bottom wall 18. The front wall 11 is pivotal relative to the remainder of the housing by means of hinge connection with the top wall 14.

The housing can be constructed from any suitable materials such as a plastics material or rubber. Typical dimension for a housing for the use with a double socket will be width 145mm, depth 45mm and height 85mm.

The rear wall 12 of the housing, as illustrated in Figure 3, is formed with two groups of apertures 18,19 whose location and size correspond to the locations and size of the apertures on a conventional dual face plate socket which can receive the pins of an electrical plug. In addition the rear wall 12 is formed with two further apertures 20 whose position corresponds to those of switches that are conventionally provided on such wall socket face plates.

The base 18 of the housing is provided with longitudinal slots 22 which can receive the cables to which an electrical plug is attached.

Mounted within the housing and shown schematically at 24 is a heat sensor.

The heat sensor is electrically coupled to a micro switch which is associated with a fire retardant material in the form of conventional fire extinguishing powder which is supported from the top wall 14 of the housing. The fire retardant material is illustrated schematically at 26 in figure 2 of the drawings.

The end wall 15 of the housing includes through slots 28 which provide ventilation for the interior of the housing.

Figures 4 to 6 illustrate one way in which fire extinguishing powder can be accommodated in the housing 10. The powder 30 is disposed within a pocket or container 31 which can be hinged at 32 to a side wall of the housing. Four

such pockets 31 can be assembled in a configuration illustrated in plan view in figure 5 of the drawings. The pockets have arcuate parts 33 which when the pockets are located in the arrangement shown in figure 5 define a circular opening 34 at the central area thereof. This opening can accommodate a micro switch with projecting, releasable lugs 35 as shown in Figure 6 of the drawings. The lugs 35 when in their projecting position locate within a recess 36 provided in the arcuate portion 32 of each pocket 31. When so located these lugs hold the pocket with the powder in their inoperative position against the top wall 14 of the housing.

In operation the housing 10 is located in position against a face plate socket by lifting the front wall 11 as shown in figure 2 and then locating the rear wall 12 against the sockets so that the pins of an electrical plug or plugs can be located through the apertures 18 and 19 to engage contacts within the sockets. The positioning of the plugs in their sockets secures the housing 10 against the wall of the building which carries the socket and because the housing is relatively light no additional means are required to hold the housing in place. Electrical leads from the plugs can pass out of the housing 10 through the slots 22. Once in position the front wall 11 is moved to its closed position shown in Figure 1 of the drawings.

As can be appreciated in this position the plugs which are engaged in their associated sockets are completely enclosed by the housing 10. If a fire inducing condition is created in the vicinity of the plug then this will be sensed by the heat sensor 24 which in turn produces an electrical signal to actuate the micro switch located near the powder pockets 31. In response the lugs 35 retract thereby releasing the pockets so that they can pivot downwardly and release the powder 30 into the interior of the housing 10. This immediately extinguishes any fire which may have been generated as a result of the fault.

It will be appreciated that although the embodiment described above shows a housing for a dual socket configuration it can also be designed to operate with a single socket face plate or multi-socket face plates. The basic principle remains the same which is to provide a housing which accommodates an electrical plug located in the socket and which on sensing a fire condition immediately releases fire retardant powder into the interior of the housing to extinguish any fire.

It will also be appreciated that the housing 10 can be aesthetically designed so that it matches in an attractive way with the surroundings of the room within which it is located. Also it will hide unsightly plugs and sockets.

It will also be appreciated that in addition to the heat sensor and micro switch there may be provided an associated audible alarm which is triggered when the heat sensor 24 senses a fire condition.

As mentioned above the fire extinguishing powder may be any conventional

(O, W dry commercially available powder such as ABC, pry Powder Mono-

Ammonium Phosphate & Ammonium Sulphate.

The housing 10 also has the advantage that it can be used to prevent tampering with an electrical plug in a socket by virtue of the fact that it hides the plug.

Another embodiment which uses a heat sensor and alarm is shown in Figures 7 to 11. Referring to Figures 7 to 11 a housing for an electrical socket comprises a rear frame part 50 which is generally of inverted U-shape. The inner parts of the side limbs 51, 52 and top limbs 53 of the frame are designed to locate behind the housing 55 of an electrical socket as shown in Figures 8 and 9 of the drawings. This is achieved by loosening the screws holding the socket, locating the limbs 51. 52 and 53 behind the socket and retightening the screws.

The housing includes an integrally formed cover 56 which is pivotally connected to the frame part 50 by an integral hinge 57. The cover can pivot

between an open position (Figures, 7 and 8) and a closed position (Figure 9). Closure clips 58 formed on the frame can engage slits 60 in the cover to retain the cover in its closed position. The lower part of the cover is cut away at 61 to allow electrical leads of a plug 63 to extend therethrough (Figure 9).

The housing may be formed from flame retardant plastic.

The housing accommodates a heat sensor 62 (Figure 11) which has an associated light 64 and sound generator 66. When the heat sensor senses a fire inducing condition it activates the light to issue a visible warning signal and a generator 66 to issue an audible warning signal.

As shown in Figure 10 the front part of cover can receive an insert 70 and a window 72 which enables the housing to be matched to the surrounding decor and thereby look attractive.

Claims

1. Apparatus for use in indicating a fire or a fire inducing condition in the vicinity of an electrical plug and socket comprising a housing which is configured so that it can be held in position over a plug socket connection when the plug is located in the socket, and heat sensing means associated with the housing for issuing a warning signal in response to the sensing of a fire inducing condition.

2. Apparatus according to claim 1 wherein the warning signal is a visible warning signal.

3. Apparatus according to claim 1 or claim wherein the warning signal is an audible warning signal.

4. Apparatus according to any preceding claim wherein the housing includes a U shaped rear part arranged to located behind an electrical socket and a cover pivotally connected to the rear part.

5. Apparatus according to any preceding claim wherein the housing is made from flame retardant plastic.

6. Apparatus for use in preventing or extinguishing a fire at or in the vicinity of an electrical plug and socket connection comprising a housing which is configured so that it can be held in position over the plug socket connection when the plug is located in the socket, a fire retardant material releasably secured in said housing, and an actuating means operable in response to the sensing of a fire inducing condition to cause the release of said fire retardant material to the interior of the housing.

7. Apparatus according to claim 6 wherein the actuating means comprises a heat sensor and an associated micro switch which is operable when the heat sensor senses a fire inducing condition to cause the release of the fire retardant material.

8. Apparatus according to claim 6 or claim 7 wherein the fire retardant material comprises a conventional fire extinguishing powder.

9. Apparatus according to any one of the preceding claims 6 to 8 which is designed for use with either single or multi-plug sockets.

10. Apparatus for use in preventing or extinguishing a fire at or in the

vicinity of an electrical plug and socket connection substantially as hereinbefore described with reference to and as shown in Figures 1 to 6 or Figures 7 to 11 of the accompanying drawings.