FIELD OF THE INVENTION THIS INVENTION relates to a fire extinguisher and to a fire fighting system. BACKGROUND TO THE INVENTION

Informal settlements throughout the world have as a common feature the fact that the shacks are close together. Access is usually via narrow passageways which fire- fighting vehicles cannot get through. When a fire occurs many shacks are burned down as the fire spreads quickly from shack to shack and the fire fighters cannot get to the blaze with their trucks and other heavy equipment. There are also cities in the world such as Tokyo where the dwellings are formal but close together and access for fire fighting trucks is limited.

The present invention provides a fire fighting system which enables a fire in areas such as discussed above to be fought more efficiently.

BRIEF DESCRIPTION OF THE INVENTION

According to one aspect of the present invention there is provided a fire extinguisher which incorporates a radio transmitter / receiver, an audible alarm and a motion sensor for activating said transmitter and said alarm upon the extinguisher being moved.

Said extinguisher preferably comprises a body for receiving fire fighting medium under pressure and a base containing said transmitter, alarm and motion sensor. The extinguisher can also include a light source.

The light source and the transmitter can be powered by a battery and there can be a solar panel for charging the battery.

A plurality of light emitting diodes are preferably provided and said radio receiver can be connected to at least one of said light emitting diodes so that said one diode can be switched on from a remote location. In the preferred form there is a red light emitting diode, a green light emitting diode and a further light emitting diode of a different colour, said radio receiver being connected to switch said further diode on.

The extinguisher can include an RFID tag with a unique number, and can also include a proximity sensor for sensing the presence of a person in the vicinity of the extinguisher and causing a warning sound to be emitted.

According to another aspect of the present invention there is provided a fire fighting system which comprises a plurality of extinguishers as defined above distributed in an area to be protected, the extinguishers all using the same radio frequency, the arrangement being such that the signal transmitted on activation of one radio frequency transmitter is received by the receivers of other extinguishers and the audible alarms thereof are activated.

The system can also include a base station for receiving said radio frequency signals. BRIEF DESCRIPTION OF THE DRAWING

For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which:- Figure 1 illustrates a fire extinguisher in accordance with the present invention; and Figure 2 illustrates a fire fighting system in accordance with the present invention.

DETAILED DESCRIPTION OF THE DRAWING

Figure 1 of the drawings shows a portable fire extinguisher 10. The extinguisher 10 comprises a metal pressure body 12 which contains fire fighting medium in the form of foam or powder under pressure. The operating handle which opens the extinguisher is shown at 14.

The extinguisher further comprises a base 16 which is fitted to the body 12. The base 16 can be cup-like and have an upwardly open recess into which the body 12 is pressed. The base 16 contains a combined battery and a solar panel 18 for battery charging purposes, an audible alarm 20 such as a siren, a light source 22 such as an LED and a light level sensor for controlling operation of the light source, a two way radio 24 and a motion detector 26. The base further includes an RFID tag so that each fire extinguisher can be identified. The tag also permits the extinguisher to be tracked if it is moved from its allocated position. The base 16 is preferably of a plastics material with no re-sale value.

In another form the base can be constituted by a curved casing which fits against the cylindrical side wall of the body 12 and is secured to the body by a strap which passes around the body.

A plurality of extinguishers are distributed through the area to be protected. The extinguishers 10 can, as shown in Figure 2, be distributed in groups 28. All of the extinguishers in a group use the same radio frequency. There can also be a monitoring station 30 capable of receiving radio frequency signals from the extinguishers of the multitude of groups in an informal settlement or other area with closely packed dwellings. In Figure 2 there are six groups 28. Simply by way of illustration there are seven extinguishers 10 in each group and the centre one of each group is diagrammatically shown as being in alarm mode and transmitting an alarm signal.

In the event of a fire one of the extinguishers is lifted and this motion is detected by the motion detector 26. This actives the audible alarm 20 and also the light source 22 if the ambient light level is low. Simultaneously it transmits a radio signal which is received by all the extinguishers in the same group and which are tuned to the same radio frequency. This activates the audible alarms of all the extinguishers in the group. The community is thus alerted to the fire and can attack it using all the extinguishers in the vicinity. By arranging the extinguishers in groups, activation of only the extinguishers in the immediate vicinity follows lifting of one extinguisher. This prevents the extinguishers of the entire settlement being activated and also results in the monitoring station being able accurately to pin point the seat of the fire. The lifting of an extinguisher can also be used to alert the community in the event of a crime or a lost child. As the siren and possibly the light are activated when the extinguisher is lifted, this is a deterrent to theft as the extinguisher cannot be carried away without the community being aware that an extinguisher has been moved. To prevent vandalism in the form of using the operating handle 14 to discharge the contents without lifting the extinguisher, the handle can be rendered inoperative whilst the extinguisher is vertical. One possible form comprises a ball in a groove, the ball preventing the handle from being activated. Lifting and tilting of the extinguisher causes the ball to roll from its handle locking position to a position in which it no longer interferes with operation of the handle.

In an alternative form a holder is provided for the extinguisher and this includes a pin which interlocks with the handle to prevent its operation. On lifting of the extinguisher from the holder, the pin is detached from the handle and the handle can then be activated. It will be understood that inevitably the siren is simultaneously activated.

The light sources of the extinguishers provide a low level of lighting in any area where illumination is required. The light level sensor incorporated into the base means that only below a certain ambient lighting level will the light come on with the siren.

The bases 16 of the extinguishers 10 can if desired be equipped with sensors for detecting faults and any other parameters that it is desired to monitor, and appropriate radio frequency signals can be transmitted to the base station.

Each RFID tag has a unique number. A supervisor of the system can at intervals tour the area passing close enough to each extinguisher to pick up the information on each tag on a portable RFID reader. If the extinguishers have fault sensors, information from these will also be picked up. That an extinguisher is missing or faulty will become apparent and remedial steps taken to maintain the integrity of the system at all times. A proximity sensor can be incorporated into the base 12. This detects any person in the vicinity of the extinguisher and causes a warning sound to be emitted. The warning can be visual or audible and is at a low level. In an emergency this warning would be ignored and the extinguisher lifted. However, it is intended to deter a person who might otherwise lift or tamper with the extinguisher when there is not an emergency.

The base 16 can incorporate sensors to detect fault conditions and an array of LEDs of different colours. In conventional manner a green LED can indicate that all systems are functioning and a red LED can indicate that one of the components in the base 16 has a fault. The array includes at least one LED that is a colour different to red and green.

The two way radio, which is preferably constituted by a mobile phone (cellphone), can be used to activate, from a remote location, that LED which is other than red and green so that it switches on, either emitting a steady light or flashing on and off.

The body of the extinguisher carries a notice instructing the action that a person seeing the flashing or steadily illuminated LED should take. This instruction will be, for example, that the person who has noticed the illuminated LED should send a SMS to a given number.

The message sent can form part of a promotion or competition and its receipt may be used in any chosen manner. A technical advantage of this procedure is that it ensures that passersby will look at the extinguishers noting if an extinguisher is missing or a red fault light is flashing.

The body 12 provides space to which advertisements may be applied.