GB2149658A

GB2149658A - Fire extinguishing systems

Info

Publication number: GB2149658A
Application number: GB08330772A
Authority: GB
Inventors: John Lawrence Wain
Original assignee: Barcrest Ltd
Current assignee: Barcrest Ltd
Priority date: 1983-11-18
Filing date: 1983-11-18
Publication date: 1985-06-19
Also published as: GB8330772D0; GB2149658B

Abstract

Housed electrical apparatus such as a domestic television set or a coin- operated fruit machine contains a reservoir (3) filled with fire- extinguishing fluid. The fluid is automatically released into the housing onto electrical components of the apparatus in the event that a dangerously elevated temperature of smoke is detected or is released manually. <IMAGE>

Description

SPECIFICATION Fire extinguishing systems This invention relates to fire extinguishing systems.

With housed electrical apparatus fires can be caused due to internal electrical faults and there is the problem that the presence of the apparatus housing can delay detection of the fire and restrict access for extinguishing purposes.

An object of the present invention is to overcome or at least appreciably reduce this problem.

According to the invention therefore there is provided a housed electrical apparatus characterised in that at least one reservoir containing a fire-extinguishing fluid is mounted relative to the apparatus housing and a control device is provided for effecting release of said fluid from the reservoir into said housing.

With this arrangement, in the event of a fire occurring within the apparatus housing, this can be extinguished quickly and conveniently by releasing the fire-extinguishing fluid.

The fluid may be of any suitable kind although preferably a non-conductive gas or volatile liquid is used such as carbon dioxide or a low boiling point halocarbon. Where the fluid is a gas at normal temperature, this may be stored in the reservoir under pressure or in liquefied or dissolved condition as appropriate.

With regard to the control device this may be manually and/or automatically operable. Most preferably the control device is temperaturesensitive and operates automatically to release the fluid when the temperature exceeds a predetermined value. Thus, the control device may comprise a fusible plug or rupturable element which melts or breaks to free an outlet orifice when the predetermined temperature is exceeded. If a local power source is conveniently available an electrical heat sensor and/or an electrical smoke sensor connected to a solenoid valve or the like may be used.

The reservoir may be of any suitable structure and may be mounted in any suitable manner at any suitable location within the housing. Thus, for example, the reservoir may comprise a vessel or cylinder or the like having an outlet thereto which may be directed towards an internal part of the apparatus prone to fire risk such as a motor or solenoid or transformer.

The said apparatus may be of any suitable kind and thus, for example, may comprise a coinoperated entertainment machine (such as a fruit machine) or domestic electrical apparatus such as a television set or the like.

The fire extinguishing arrangement may be used in conjunction with an automatic device which operates to give an audible and/orvisual alarm and/ or which disconnects electrical suppiy from the apparatus when a dangerously elevated temperature or smoke is detected.

The invention will now be described further by way of example only and with reference to the accompanying drawings in which: Fig. 1 is a partially cut-away diagrammatic perspective view from the rear of domestic electrical apparatus such as a television set incorporating a fire extinguishing arrangement according to one embodiment of the invention; and Fig. 2 is diagrammatic side view to a larger scale showing the fire extinguishing arrangement of Fig.

1.

Fig. 1 shows electrical apparatus comprising a box-structure housing 1 containing electrical circuitry.

The housing 1 has a top wall 2 and beneath this there is fixed (by means of a clip 4) a small pressure cylinder 3 containing a fire-extinguishing fluid which is heavier than air, non-conductive (electrically) and generally non-toxic. Suitably, the cylinder 3 may contain carbon dioxide gas under pressure.

The cylinder 3 has an outlet 5 at one end and this is closed with a valve incorporating a fusible or heatrupturable plug 6. The outlet 5 is connected to a nozzle 7 which is directed downwardly particularly towards circuitry or electrical components of the apparatus prone to faults which may give rise to the generation of heat sufficient to cause combustion.

In use, in the event that combustion occurs or is imminent, the generated heat fuses or ruptures the plug 6 and thereby the contents of the cylinder 3 are released so as to fill the housing with the fire extinguishing fluid and in particular to apply a blanket thereof over the circuitry and components beneath the nozzle 7. In this way combustion can be extinguished or prevented quickly and conveniently.

It is of course to be understood that the invention is not intended to be restricted to the details of the above embodiment which are desribed by way of example oniy. Thus, for example, if desired two or more of the cylinders may be provided at different positions within the housing.

Further, provision may be made for intervening in the electrical circuitry of the apparatus when the fire extinguishing system triggers, particularly by isolating such circuitry from the mains or other power source. Conveniently, the cylinder 3 may be linked to a pressure-operated (e.g. diaphragm) switch which is connected in series with the power source and which is held closed (conductive) by the pressurised fluid in the cylinder, the arrangement being such that the switch opens automatically when the fluid pressure falls below a predetermined value due to release of such fluid via the plug 6. This arrangement advantageously is fail safe in so far as the switch will open in the event that the cylinder loses fluid due to leakage.

1.A A housed electrical apparatus characterised in that at least one reservoir containing a fireextinguishing fluid is mounted relative to the apparatus housing and a control device is provided for effecting release of said fluid from the reservoir into said housing.

2. Apparatus according to claim 1, wherein the control device is temperature-sensitive and operates automatically to release the fluid when the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Fire extinguishing systems This invention relates to fire extinguishing systems. With housed electrical apparatus fires can be caused due to internal electrical faults and there is the problem that the presence of the apparatus housing can delay detection of the fire and restrict access for extinguishing purposes. An object of the present invention is to overcome or at least appreciably reduce this problem. According to the invention therefore there is provided a housed electrical apparatus characterised in that at least one reservoir containing a fire-extinguishing fluid is mounted relative to the apparatus housing and a control device is provided for effecting release of said fluid from the reservoir into said housing. With this arrangement, in the event of a fire occurring within the apparatus housing, this can be extinguished quickly and conveniently by releasing the fire-extinguishing fluid. The fluid may be of any suitable kind although preferably a non-conductive gas or volatile liquid is used such as carbon dioxide or a low boiling point halocarbon. Where the fluid is a gas at normal temperature, this may be stored in the reservoir under pressure or in liquefied or dissolved condition as appropriate. With regard to the control device this may be manually and/or automatically operable. Most preferably the control device is temperaturesensitive and operates automatically to release the fluid when the temperature exceeds a predetermined value. Thus, the control device may comprise a fusible plug or rupturable element which melts or breaks to free an outlet orifice when the predetermined temperature is exceeded. If a local power source is conveniently available an electrical heat sensor and/or an electrical smoke sensor connected to a solenoid valve or the like may be used. The reservoir may be of any suitable structure and may be mounted in any suitable manner at any suitable location within the housing. Thus, for example, the reservoir may comprise a vessel or cylinder or the like having an outlet thereto which may be directed towards an internal part of the apparatus prone to fire risk such as a motor or solenoid or transformer. The said apparatus may be of any suitable kind and thus, for example, may comprise a coinoperated entertainment machine (such as a fruit machine) or domestic electrical apparatus such as a television set or the like. The fire extinguishing arrangement may be used in conjunction with an automatic device which operates to give an audible and/orvisual alarm and/ or which disconnects electrical suppiy from the apparatus when a dangerously elevated temperature or smoke is detected. The invention will now be described further by way of example only and with reference to the accompanying drawings in which: Fig. 1 is a partially cut-away diagrammatic perspective view from the rear of domestic electrical apparatus such as a television set incorporating a fire extinguishing arrangement according to one embodiment of the invention; and Fig. 2 is diagrammatic side view to a larger scale showing the fire extinguishing arrangement of Fig. 1. Fig. 1 shows electrical apparatus comprising a box-structure housing 1 containing electrical circuitry. The housing 1 has a top wall 2 and beneath this there is fixed (by means of a clip 4) a small pressure cylinder 3 containing a fire-extinguishing fluid which is heavier than air, non-conductive (electrically) and generally non-toxic. Suitably, the cylinder 3 may contain carbon dioxide gas under pressure. The cylinder 3 has an outlet 5 at one end and this is closed with a valve incorporating a fusible or heatrupturable plug 6. The outlet 5 is connected to a nozzle 7 which is directed downwardly particularly towards circuitry or electrical components of the apparatus prone to faults which may give rise to the generation of heat sufficient to cause combustion. In use, in the event that combustion occurs or is imminent, the generated heat fuses or ruptures the plug 6 and thereby the contents of the cylinder 3 are released so as to fill the housing with the fire extinguishing fluid and in particular to apply a blanket thereof over the circuitry and components beneath the nozzle 7. In this way combustion can be extinguished or prevented quickly and conveniently. It is of course to be understood that the invention is not intended to be restricted to the details of the above embodiment which are desribed by way of example oniy. Thus, for example, if desired two or more of the cylinders may be provided at different positions within the housing. Further, provision may be made for intervening in the electrical circuitry of the apparatus when the fire extinguishing system triggers, particularly by isolating such circuitry from the mains or other power source. Conveniently, the cylinder 3 may be linked to a pressure-operated (e.g. diaphragm) switch which is connected in series with the power source and which is held closed (conductive) by the pressurised fluid in the cylinder, the arrangement being such that the switch opens automatically when the fluid pressure falls below a predetermined value due to release of such fluid via the plug 6. This arrangement advantageously is fail safe in so far as the switch will open in the event that the cylinder loses fluid due to leakage. CLAIMS

2. Apparatus according to claim 1, wherein the control device is temperature-sensitive and operates automatically to release the fluid when the temperature exceeds a predetermined value.

3. Apparatus according to claim 2, wherein the control device comprises a fusible plug or rupturable element.

4. Apparatus according to claim 2, wherein the control device comprises an electrical heat and/or smoke sensor connected to a valve and operated from a local power source.

5. Apparatus according to any one of claims 1 to 4, which comprises a coin-operated entertainment machine.

6. Apparatus according to any one of claims 1 to 4, which comprises domestic electrical apparatus.

7. Apparatus according to any one of claims 1 to 6, further including an automatic device which operates to give an audible and/or visual alarm when a dangerously elevated temperature or smoke is detected.

8. Apparatus according to any one of claims 1 to 7, further including an automatic device which operates to disconnect electrical supply from the apparatus when a dangerously elevated temperature or smoke is detected.

9. Apparatus according to claim 1, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.