Position and operation signalling apparatus for fire extinguishers and fire extinguishing system comprising such an apparatus

0001The present invention relates to a position and operation signalling apparatus for fire extinguishers and to a fire extinguishing system comprising such an apparatus, and more in particular to a position signalling apparatus for fire extinguishers for facilitating the detection of fire extinguisher position in case of fire, and to a fire extinguishing system comprising a wireless communication network between fire extinguishers belonging to the fire extinguishing system itself.

0002As known, electric system protections are activated in case of fire, which provide for interrupting the supply of electricity and activating an emergency lighting system. The emergency lighting system has a lower intensity than the normal lighting system; therefore, the visibility is highly reduced. Furthermore, the presence of smoke generated by the fire further worsens visibility in the involved rooms. Under these conditions, it is often very difficult to easily identify where the fire extinguishers are located and reach the closest one. The presence of an extinguisher is currently signalled by means of specific signs affixed on the wall close to the fire extinguisher itself. It is apparent that poor ambient lighting and the concurrent presence of smoke make these signs completely inadequate to be easily identified in order to consequently identify the fire extinguisher.

0003It is the object of the present invention to provide a position and operation signalling apparatus for fire extinguishers and a fire extinguishing system comprising such an apparatus which solves the problems of the prior art.

0004According to the present invention, a position and operation signalling apparatus for fire extinguishers and a fire extinguishing system comprising such an apparatus are provided as defined in claims 1 and 17.

0005For a better understanding of the present invention, preferred embodiments will now be described by way of non-limitative example, only with reference to the accompanying drawings, in which: <ul id="ul0001" list-style="dash" compact="compact"><li><figref idref="f0001">figure 1</figref> shows the outer casing of a position signalling apparatus for fire extinguishers placed on the handle of a fire extinguisher, according to an embodiment of the present invention;</li><li><figref idref="f0002">figure 2</figref> shows the outer casing of a position signalling apparatus for fire extinguishers placed on the base of the handle of a fire extinguisher, according to a further embodiment of the present invention;</li><li><figref idref="f0003">figure 3</figref> shows a fire extinguisher provided with the position signalling apparatus in <figref idref="f0001">figure 1</figref> or <figref idref="f0002">figure 2</figref> and arranged in a room;</li><li><figref idref="f0004">figure 4</figref> shows an electronic circuit for powering, controlling and commanding the position signalling apparatus for fire extinguishers according to an embodiment of the present invention;</li><li><figref idref="f0004">figure 5</figref> shows another embodiment of the electronic circuit for powering, controlling and commanding the position signalling apparatus for fire extinguishers;</li><li><figref idref="f0005">figure 6</figref> shows a pressure detector for fire extinguishers adapted to be used in the circuit in <figref idref="f0004">figure 5</figref>;</li><li><figref idref="f0005">figure 7</figref> shows a further embodiment of the electronic circuit for powering, controlling and commanding the position signalling apparatus for fire extinguishers;</li><li><figref idref="f0006">figure 8</figref> shows a wireless network of a fire extinguishing system comprising a plurality of position signalling apparatuses of respective fire extinguishers according to the present invention;</li><li><figref idref="f0007">figure 9</figref> shows a coordination device adapted to be interfaced with the position signalling apparatuses belonging to the wireless network in <figref idref="f0006">figure 8</figref> and with an operator and/or a control room external to the wireless network; and</li><li><figref idref="f0007">figure 10</figref> shows a maintenance device adapted to be interfaced with the position signalling apparatuses belonging to the wireless network in <figref idref="f0006">figure 8</figref> to carry out maintenance operations on the position signalling apparatuses.</li></ul>

0006<figref idref="f0001">Figure 1</figref> shows a fire extinguisher 2 comprising a handle 1 provided with a signalling apparatus 3 (here seen from the outside) according to an embodiment of the present invention.

0007According to such an embodiment, the signalling apparatus 3 comprises a casing 4, made for example of soft plastic material and shaped so as to adapt to the lower handle of the fire extinguisher 2 and be integral therewith. Appropriate fastening means (not shown) may be provided to promote the coupling thereof. Thereby, the grip of the fire extinguisher 2 by a user is not compromised by the presence of the signalling apparatus 3.

0008<figref idref="f0002">Figure 2</figref> shows a fire extinguisher 2 provided with a signalling apparatus 3' (seen from the outside) according to a further embodiment of the present invention. The signalling apparatus 3' comprises a casing 4', e.g. made of either hard or soft plastic material and provided with fastening means 12 adapted to couple the signalling apparatus 3', by means of the casing 4', to the base 1' of the handle 1 of the fire extinguisher 2. For example, the casing 4' may be integral with a pressure gauge 11 with which all fire extinguishers are provided. Thereby, the fastening means of the casing 4' correspond to the fastening means of the pressure gauge 11 to the fire extinguisher 2. Alternatively, instead of being integral with the pressure gauge 11, the casing 4' may be fixed to the fire extinguisher 2 by means of the same screw for fastening the pressure gauge 11 to the fire extinguisher 2. Or again, the casing 4' may be fixed to the base 1' of the handle 1 by means of an adjustable circular-section ring.

0009As known, the pressure tightness between pressure gauge 11 and fire extinguisher 2 is ensured by an o-ring, mounted on the seat of the pressure gauge 11 and which is engaged in the valve (not shown) of the fire extinguisher 2. In order to prevent the sealing capacity of the o-ring from altering upon fastening the signalling apparatus 3' to the pressure gauge 11, an accessory ring which is fastened by means of a screw nut onto the collar of the valve where the pressure gauge 11 is screwed may be used.

0010The following operations may be performed, for example, for mounting the signalling apparatus 3: removing the pressure gauge 11; inserting the nut in the collar of the valve; screwing the pressure gauge 11; coupling the signalling apparatus 3' to the pressure gauge 11 or to the base 1' of the handle 1 of the fire extinguisher 2.

0011In both embodiments in <figref idref="f0001">figures 1</figref> and <figref idref="f0002">2</figref>, the grip of the fire extinguisher 2 by a user is not compromised by the presence of the signalling apparatus 3 or 3'.

0012Regardless of the embodiment and coupling of the signalling apparatus 3, 3' to the fire extinguisher 2, the casing 4, 4' has a housing 5, for accommodating one or more batteries (not shown) inside the casing 4, 4' itself, and an opening 6 for emitting a light beam 7 towards the outside of the casing 4, 4'. Such a light beam 7 may be generated by a focused LED or LASER device, as described in greater detail below with reference to <figref idref="f0004">figures 4 and 5</figref>.

0013With combined reference to <figref idref="f0001 f0002 f0003">figures 1-3</figref>, the light beam 7 is advantageously projected towards a ceiling 8 of a room 10 in which the fire extinguisher 2 is placed, and forms a luminous image 9 on the ceiling 8. The luminous image 9 may be of various shapes and sizes, e.g. it may be a luminous spot or circle or it may form a letter "E" standing for the word "Extinguisher". Thereby, a user 11 looking for the fire extinguisher 2 in an assumed poorly lit room 10 (with emergency lighting) and/or with the presence of smoke is facilitated in searching the fire extinguisher 2 itself because the luminous image 9 may be located with a gaze from various angles. Indeed, in an environment full of smoke, a simple lamp would be poorly visible due to the scattering of light rays by the suspended particles, while the visibility of a beam generated by focused LED or LASER is, on the contrary, increased precisely because of such a scattering phenomenon. Furthermore, the light beam 7 being projected at a distance from the fire extinguisher 2, possible obstacles present close to the fire extinguisher 2, which could obstruct the sight of an operator looking for the fire extinguisher 2, are not a significant hindrance to the visual location of the fire extinguisher itself 2.

0014<figref idref="f0004">Figure 4</figref> schematically shows an electronic power, control and command circuit 15 of a LASER device 16 configured to generate the light beam 7. In an first embodiment thereof, the electronic circuit 15 comprises a battery 20, e.g. adapted to generate a 3V voltage, a microprocessor circuit 21 and a pilot switch 22, e.g. a MOSFET device serving the function of switch. The battery 20 supplies the power needed for their operation to the microprocessor circuit 21 and to the LASER device 16. A small-size, rechargeable lithium battery adapted to be placed inside the housing 5 (shown in <figref idref="f0001">figure 1</figref> or <figref idref="f0002">2</figref>) is advantageously used.

0015The LASER device 16 is controlled by the electronic circuit 15, in order to generate a pulse on timing (intermittent on/off operation of the LASER device 16). The microprocessor circuit 21 alternatively controls the pilot switch 22, which in turn controls the LASER device 16 on/off, to either conduct or cut-off stages.

0016The pulse on timing serves a three-fold function. Firstly, it allows to minimize current consumption and to preserve the energy of the battery 20; then, it promotes the visual perception of the luminous image 9 by the human eye which, as known, is particularly sensitive to image variations more than to a fixed image; and finally it reduces up to eliminating the problem of danger of possible accidental pointing of the light beam 7 towards the human eye.

0017For example, an on/off timing of the LASER device 16, with 10 ms in on-state and 900 ms in off-state, is used; these values ensure an optimal persistence time for the human eye, and the frequency may be further automatically varied according to the operating conditions of the fire extinguisher 2. For example, an excessively low value of the inner pressure of the fire extinguisher 2 may be signalled by varying the on/off timing of the LASER device 16, i.e. by controlling it for 10 ms in on-state and 300 ms in off-state.

0018In order to maximize the energy saving, the voltage supplied by the battery 20 to the LASER device 16 is modulated by means of PWM (Pulse Width Modulation) for allowing to minimize the energy dissipation while maintaining a maximum illumination during the whole discharge time of the battery 20.

0019The PWM modulation of input current to the laser device 16 may be managed by the microcontroller circuit 21.

0020The advantage of using PWM modulation is first the drastic reduction of power dissipated by the electronic circuitry, because the electronic power devices of known type (MOSFET, IGBT, etc.) minimize the energy dissipation when they work under two conditions of saturation or interdiction only.

0021<figref idref="f0004">Figure 5</figref> shows an electronic circuit 23 according to a further embodiment. Like that shown in <figref idref="f0004">figure 4</figref>, the electronic circuit 23 in <figref idref="f0004">figure 5</figref> comprises a battery 20, a microprocessor circuit 21 and a pilot switch 22, but differs from the electronic circuit 15 in <figref idref="f0004">figure 4</figref> for the additional presence of an energy converter 19, adapted to convert the light energy possibly present in the environment (e.g. the room 10, <figref idref="f0003">figure 3</figref>) into electricity to charge the battery 20 and/or to directly power the microprocessor circuit 21; a sensor/indicator block 26 connected to the microprocessor circuit 21, comprising at least one pressure sensor 27 used for acquiring a pressure value inside the fire extinguisher 2; a sound generator 30 connected to the microprocessor circuit 21, e.g. a piezoelectric buzzer, for generating an alarm sound signal; and a communication interface 31 (e.g. a radio type interface), powered by the battery 20 and connected to the microprocessor circuit 21, for transmitting fire alarm signals or operating fault signals of the fire extinguisher 2 to a control room and/or to a maintenance operator (not show) remotely located with respect to the fire extinguisher 2 itself. The control room and/or operator may be indifferently located either close to the room 10 or far from the room 10 itself, e.g. in another building, to monitor all the possible alarms or operating faults of all the fire extinguishers (provided with the signalling apparatus 3, 3' comprising the electronic circuit 23 provided with a communication interface 31) present in a residential dwelling or workplace.

0022The sensor block 26 may further comprise other sensor types, such as, for example, a light sensor 28, used for measuring luminosity in the room 10 and/or a temperature sensor 29 and/or an accelerometer 32 or even other sensors.

0023The accelerometer 32 is preferably of the triaxial type and is adapted to detect unauthorized movements of the fire extinguisher 2 (e.g. theft) and to send an unauthorized movement signal to the microprocessor 21, which in turn controls the communication interface 31 to send an unauthorized movement signal of the fire extinguisher 2 to a control room and/or an operator.

0024The pressure sensor 27 may be advantageously either connected to the original pressure gauge with which all powder fire extinguishers are provided, e.g. as an extension or fitting of the original pressure gauge, or may be connected to a pressure indicator mounted instead of the original pressure gauge (e.g. of the type shown in <figref idref="f0005">figure 6</figref> and described with reference to such a figure).

0025The microprocessor circuit 21 periodically diagnoses the fire extinguisher 2 by acquiring the pressure value inside the reservoir of the fire extinguisher 2 from the pressure sensor 27. If the pressure in the reservoir drops below a minimum threshold value expected for a correct operation, the microprocessor circuit 21 controls the sound generator 30 in order to generate faulty operation sound signals of the fire extinguisher 2 which may be heard by people in transit or residing close to the fire extinguisher 2 itself. These signals are generated with the purpose of attracting attention and prompting people in transit to inform the operators in charge of fire extinguishing system maintenance to restore the correct operation of the fire extinguisher 2. Alternatively or additionally to the sound signalling, in case of anomalous pressure in the reservoir of the fire extinguisher 2, the microprocessor circuit 21 further controls the communication interface 31 in order to transmit operating fault signals of the fire extinguisher 2 to a control room and/or to an operator in charge of maintenance.

0026A pressure indicator 39 adapted for the illustrated purposes, installable instead of or by the side of the original pressure gauge of the fire extinguisher 2, is schematically shown in <figref idref="f0005">figure 6</figref>. The pressure indicator 39 comprises a pressure indicator needle 40 including in turn a magnetic element 41. The magnetic element 41, e.g. made of neodymium, may be integrated in the pressure indicator needle 40, or applied to the pressure indicator needle 40 by means of appropriate fastening means (e.g. glued or screwed) or alternatively the whole pressure indicator needle 40 may be made of magnetic material and thus it may be the magnetic element 41 itself. The pressure indicator 39 further comprises a reed bulb 42, of known type. The reed bulb 42 comprises first and second ferromagnetic foils 42' and 42", generally made of iron and nickel tightly sealed in a glass casing. The ferromagnetic foils 42', 42", electrically polarized in a convenient manner, overlap apart from one another inside the casing and, under rest conditions, are not conducting because they are separated by a small gap. However, when subjected to an appropriate magnetic field (in the example shown, generated by the magnetic element 41), the first and second foils 42' and 42" come in direct contact with each other and an electric signal crosses the terminals (not shown) of the reed bulb 42. The reed bulb 42 is inserted into the pressure indicator 39 and spatially arranged in correspondence of at least one anomalous operating zone 43', 43", indicating an anomalous operation of the fire extinguisher 2 (excessively high or excessively low pressure), in all cases beyond a correct operating zone 44 indicating a correct operation of the fire extinguisher 2.

0027When the pressure indicator needle 40 comprising the magnetic element 41 is outside the correct operating zone 44, the reed bulb 42 is activated thus causing the direct contact of the first foil 42' with the second foil 42". The state of the reed bulb 42 (open contact or closed contact) may be monitored either constantly or at regular intervals by the microprocessor 21 which, if the reed bulb 42 is active and conducting, may signal the event by means of an anomalous operating sound signalling (by means of the sound generator 30) or by sending a message to the control room or to an operator (by means of the communication interface 31).

0028It is apparent that two reed bulbs may be inserted (in a manner not shown in the figure) into the pressure sensor 39, one at the anomalous operating zone 43', indicating an excessively low pressure, and one at the anomalous operating zone 43", indicating an excessively high pressure, on the left and on the right of the correct operating zone 44.

0029Alternatively to the use of a reed bulb 42 of the described type, a reed bulb may be used in which the first foil 42' and the second foil 42" are in electric contact with each other under the normal operating condition of the fire extinguisher 2, and the activation of a malfunction state or alarm (i.e. when the magnetic element 41 is beyond the correct operating zone 44) is subjected to the detachment between the first foil 42' and the second foil 42", caused by an appropriate magnetic field.

0030Furthermore, in order to be certain that the reed bulb 42 of the pressure indicator 39 correctly works, a capacitor (not shown) 39 may be inserted into the pressure indicator 39, connected in parallel to the reed bulb 42, having a low capacity value (e.g. 100 pF), so as not to compromise the normal operation of the pressure indicator 39. Such a capacitor may be used during the step of diagnosing, thus allowing to check the correct connection of the parts. For this purpose, the microprocessor 21 checks the correct operation by sending a short voltage step and then analyzing the received reply. If the line returns to the rest state with a delay longer than a predetermined interval (e.g. ≥ 1 µs), it means that the connection is correct, otherwise if the connection returns to the rest state in a shorter time than the aforementioned threshold, the connection is interrupted (the reed bulb 42 is not correctly working). Also in this case, the microprocessor 21 may signal the event by means of an anomalous operation sound signalling or by sending an appropriate message to the control room or to an operator. During the step of installing, diagnosing the contact will help the installer to understand if the mounting correctly occurred. Subsequently, it is used to confidently known that no faults or possible tampering have occurred.

0031Alternatively to a reed bulb 42, a pressure indicator 39 may be made, in which the activation of a malfunction event or alarm is generated by a direct mechanical contact between the pressure indicator needle 40 and an abutting element (not shown). The mechanical contact may, for example, cause the activation of an appropriate signal or, if the pressure indicator needle 40 and the abutting element are made of conducting material and appropriately polarized, may enable a flow of electric current between the abutting element and the pressure indicator needle 40. Such a current may be monitored either constantly or at regular intervals by the microprocessor 21 which, if active and conducting, may indicate the event by means of an anomalous operating sound signalling (by means of the sound generator 30) or by sending a message to the control room or to an operator (by means of the communication interface 31).

0032The pressure sensor 27 and the pressure indicator 39 may be prepared by the supplier/assembler of the fire extinguisher 2 during the assembly (for new fire extinguishers) or during the step of overhauling (for fire extinguishers already on the market).

0033<figref idref="f0005">Figure 7</figref> shows an electronic circuit 24 similar to the electronic circuit 23 in <figref idref="f0004">figure 5</figref>. Elements in common of the electronic circuit 24 and the electronic circuit 23 will not be described in further detail.

0034In addition to the elements in common to the electronic circuit 23, the electronic circuit 24 comprises a memory 25, connected to the microprocessor circuit 21 and adapted to store information which allow to univocally identify the fire extinguisher 2 to which the electronic circuit 24 is mounted. By way of example, these information may be limited to a registration number of the fire extinguisher; or may further comprise one or more of: the safety system owner's name, the address, the city, the building floor, the number or name of the room where the fire extinguisher 2 is located.

0035These information may be communicated to the control room and/or to the operator in charge of maintenance in case of incorrect operation alarm of a fire extinguisher 2. The communication interface 31 may communicate with the control room and/or or with the operator by means of a wireless or wired LAN network or by means of the cellular network (e.g. GSM, GPRS, UMTS, etc.), or other.

0036Because each fire extinguisher 2 is equipped with its own signalling apparatus 3 or 3', comprising the electronic circuit 24 in turn including a communication interface 31, a wireless network may be made, e.g. of the mesh type, between a plurality of fire extinguishers 2 present in a given place, e.g. in a same plant or office or other.

0037<figref idref="f0006">Figure 8</figref> shows a fire extinguishing system 50 comprising a plurality of fire extinguishers 2, each comprising in turn a signalling apparatus 3, 3' including the electronic circuit 24 of the type shown in <figref idref="f0004">figure 5</figref>. General reference to a fire extinguisher 2 will be made hereinafter in the description, understanding that this comprises a respective signalling apparatus 3, 3'.

0038The fire extinguishing system 50 further comprises at least one coordinator device 51, configured to be interfaced with one or more signalling apparatuses 3, 3' of respective fire extinguishers 2, for reading and writing data. The coordinator device 51 is interfaced with a public network 52 (of know type, e.g. GSM, UMTS, WIMAX, or wired network, or the Internet, or other) outside the fire extinguishing system 50, for sending information related to one or more fire extinguishers 2, belonging to the fire extinguishing system 50, to a mobile device 53 of an operator in charge of maintenance or to a control room (described in greater detail below).

0039<figref idref="f0007">Figure 9</figref> schematically shows a coordinator device 51 useable in the fire extinguishing system 50 in <figref idref="f0006">figure 8</figref>. The coordinator device 51 comprises a video 55, a microcontroller 56, a modem 57 (e.g. a GSM modem), a wireless transceiver 58, a memory 59, a housing for a SIM card 60, a GPS receiver 62 and a battery 61.

0040Some of the main activities of the coordinator device 51 are: storing operating parameters of the fire extinguishing system 50; maintaining an occurred event history (alarm situations, malfunctions, maintenance); delivering a network synchronism signal to the fire extinguishers 2 belonging to the fire extinguishing system 50; receiving and storing information (e.g. alarm or malfunction signals) transmitted by the fire extinguishers 2; querying the fire extinguishers 2 to evaluate the operation; modifying and/or acquiring operating parameters of each fire extinguisher 2 of the fire extinguishing system 50 (e.g. acquiring and modifying the blinking frequency of the LASER device 16, acquiring and modifying the blinking intensity of the LASER device 16, activating/deactivating the sound generator 30, acquiring the temperature of a fire extinguisher 2, etc.); checking that all fire extinguishers 2 of the fire extinguishing system 50 are actually present; sending alarm or malfunction signals to a predetermined telephone number, e.g. belonging to an operator in charge of maintenance of the fire extinguishing system 50; sending alarm or malfunction signals to a control room outside the fire extinguishing system 50; and, if a high safety level is required, protect the signals send and/or received by means of encryption key.

0041More in detail, the video 55 is used to display a plurality of information, e.g. the operating state of coordinator device 51 and fire extinguishing system 50 (e.g. configuration parameters, possible alarm state of one or more fire extinguishers 2 belonging to the fire extinguishing system 50, charge level of the battery of the signalling apparatuses 3, 3' with which the fire extinguishers 2 belonging to the fire extinguishing system 50 are provided, charge level of the battery of the coordinator device 51 itself, maintenance state in progress, etc.). On radio level, two simultaneously active radio connections are present: a wireless connection managed by the wireless transceiver 58, adapted to communicate in transmission/reception with all the fire extinguishers 2 of the fire extinguishing system 50, e.g. using a 2.4GHz frequency connection and a wireless LAN protocol of known type; and a wireless connection managed by the modem 57, e.g. on mobile telephone network, to alert an operator in charge of safety/maintenance of the fire extinguishers 2 in real time. The modem 57 may advantageously send communications (e.g. an SMS text message) on GSM, UMTS or other telephony network (by using a SIM card accommodated in the SIM card housing 60) or an email message via the Internet.

0042The memory 59 may contain a plurality of information, e.g. the name of the owner of the fire extinguishing system, the address, the city and for each fire extinguisher 2 present in the fire extinguishing system 50, the registration number of the fire extinguisher 2 associated to data related to the location of the fire extinguisher 2 in the building (e.g. the building floor, the number or name of the room where the fire extinguisher 2 is located).

0043Information related to the place in which the coordinator device 51 is located may be stored in the memory 59 or may be acquired by the GPS signal receiver 62 and processed by an appropriate software (e.g. of the type used for GPS navigation) residing in the memory 59.

0044The power of the coordinator device 51 is supplied by the battery 61, of rechargeable type, which in turn may be powered/recharged by an external AC/DC power unit (not shown) connected to network voltage. If the network voltage is absent, service continuity is ensured for a few days by the battery 61.

0045The consumption of the battery in case of prolonged network voltage absence or the failure of the battery 61 may be signalled to the operator in charge of the maintenance of the fire extinguishing system 50 (e.g. by means of SMS text messages).

0046Again with reference to <figref idref="f0006">figure 8</figref>, the fire extinguishers 2 communicate to one another using the respective communication interfaces 31. Each fire extinguisher 2 communicates with one or more fire extinguishers 2 within radio range, thus in fact creating a cooperative-type wireless communication network (or mesh network). Furthermore, the fire extinguishers 2 within the radio range from the coordinator device 51 communicate with the latter. When a fire extinguisher 2 is faulty (e.g. in case of excessively low or excessively high internal pressure), the faulty fire extinguisher 2 transmits an alarm message.

0047In order to deliver the alarm message to the operator and/or to the control room, the faulty fire extinguisher 2 will firstly send such an alarm message to the coordinator device 51, which forwards it to the operator's mobile device 53 and/or the control room through the public network 52. Before forwarding such an alarm message, the coordinator device generates a data packet adapted to be transmitted according to the communication protocol used by the public network 52 with which it is interfaced, in order to make it compatible therewith, and may add or remove information. For example, each fire extinguisher 2 may generate an alarm message containing its own registration number and the indication of the fault type (e.g. in the form of numeric code known by both the fire extinguisher 2 and the coordinator device 51). Prior to transmission, the coordinator device 51 may complete such an alarm message with information related to the place where the operator has to intervene.

0048If the faulty fire extinguisher 2 is not in direct radio connection with the coordinator device 51, each fire extinguisher 2 belonging to the fire extinguishing system 50 may act as a repeater for the fire extinguishers 2 within the radio range therefrom, so that the alarm message is delivered to the coordinator device 51.

0049The coordinator device 51 serves the function of synchronizing the circuits mounted to the fire extinguishers, e.g. by outputting a synchronization signal at established intervals so as to allow the resynchronization of the these circuits if these go out of synchronism, and to control the fire extinguishers 2 belonging to the fire extinguishing system 50, and furthermore it acts as an interface towards public networks 52 operating in the territory where the fire extinguishing system 50 is located.

0050If the public network 52 is a GSM network, when an alarm message is received by a fire extinguisher 2, the coordinator device 51 may forward such an alarm message as an SMS text message to an intended cellular telephone number. Furthermore, the coordinator device 51 may send the alarm message to a specific service centre where such an alarm message may be stored, processed and read.

0051The alarm message which is sent contains all the information for unequivocally identifying and locating the faulty fire extinguisher 2. By way of example, such an alarm message may contain: the registration number of the fire extinguisher, the fire extinguishing system owner's name, the address, the city, the building floor and the number or name of the room where the faulty fire extinguisher 2 is located.

0052The alerted operator who goes to the place where the faulty fire extinguisher is located may then restore the operation of the fire extinguisher 2.

0053During maintenance interventions, the operator may have a maintenance device 70 of the type shown in <figref idref="f0007">figure 10</figref>.

0054The maintenance device 70 is of the portable type and comprises a video 71, an alphanumeric keyboard 72, a transceiver 73, a microcontroller 74, a rechargeable battery 75 and interface connectors 76.

0055The maintenance device 70 acts as an interface and is used by the operator to access the memory 25 of the fire extinguishers 2, and more in general all parameters of the circuits 15, 23 and 24. It may be used both during the steps of installing the fire extinguishing system 50 and later for updates and/or maintenance.

0056The network of the fire extinguishing system 50 may advantageously be accessed in a safe mode by entering the user name and password, defined by the operator when the fire extinguishing system 50 is installed, and then freely editable.

0057The maintenance device 70 is designed to communicate with each extinguisher 2 and with the coordinator device 51. In order to simplify the operation of the fire extinguishing system 50, the maintenance device 70 may use the same protocol and frequencies defined for the fire extinguishing system 50 (e.g. a Wireless LAN protocol), but system data editing may be enabled according to one or more safety conditions, e.g. it may only occur if the level of the received signal is higher than a predetermined threshold. Thereby, only the fire extinguisher 2 or the coordinator device 51 which is a few tens of centimetres away from the maintenance device 70 may have a signal strong enough to allow the communication activation. At the same time, the communication becomes robust because it can overcome possible strong intensity, interfering signals.

0058The alphanumeric keyboard 72 and the video 71 of the maintenance device 70 serve the function of entering data into the memory 25 of the electronic circuit 24 and/or into the memory 59 of the coordinator device 51, respectively, and of displaying the information contained in these memories 25, 59 or the parameters of the fire extinguishing system 50 (signal power, transmission frequency, etc.).

0059The interface connectors 76 may comprise, for example, a power connector and a USB connector. Both may be used for recharging the battery 75. The first is used for recharging the battery 75 from an external AC/DC power source connectable to the electric network, the second is used for connecting the maintenance device 70 to a computer for saving acquired maintenance data and/or for recharging the battery 75 through the USB port.

0060Furthermore, the USB connector may be used for connecting a reading device 80, outside the maintenance device 70, such as for example an RF tag reader, or a bar code reader. In this case, the memory 25 of the electronic circuit 24 present on the fire extinguishers 2 is an RF tag or a barcode, containing identifying information of the fire extinguisher 2 (e.g. the registration number of the fire extinguisher 2).

0061Alternatively, the reading device 80 may be integrated inside the maintenance device 70.

0062Furthermore, the maintenance device 70 may store the performed maintenance intervention history or only the maintenance interventions which have not yet been billed.

0063When billing, the data are taken from the maintenance device 70 and stored in a computer (not shown) to be appropriately printed.

0064Furthermore, by means of the maintenance device 70, the data present in the memory 25 of the electronic circuit 24 of each fire extinguisher 2 may be edited to store information related to the performed maintenance intervention (if the memory so allows and is of the rewritable type). Storing maintenance data in the memory 25 ensures traceability over time.

0065During the maintenance operations, the fire extinguisher 2 undergoing the maintenance informs the coordinator device 51 that maintenance is in progress. After maintenance, the fire extinguisher 2 informs the coordinator device 51 of the performed intervention type and its operativeness. In turn, the coordinator device 51 may store the type of intervention in its memory 59.

0066During maintenance, generally once every six months, the operator in charge of maintenance replaces the battery 20 of the electronic circuit 24, carries out possible maintenance operations and, by means of the maintenance device 70, records the type of maintenance carried out in the memory 25 of the fire extinguisher 2.

0067Replacing the battery 20 once every six months is sufficient to ensure the good operation of the signalling apparatus 3, 3', particularly if consumption is optimized by turning on/off both the LASER device 16 and the communication interface 31 at regular intervals (e.g. with on/off state timing of 100 to 1). For example, for each long interval 1s, the LASER device 16 lights up for 10ms. Similarly, the communication interface 31 is turned on and off. The reception and transmission intervals are modulated by periods of rest in which the circuits are set to minimum consumption. Thereby, the battery 20 (under optimal conditions) reaches a duration of about six months, i.e. equal to the maximum maintenance time which is contemplated by many laws regarding the maintenance of fire extinguishers.

0068The advantages of the present position signalling apparatus for fire extinguishers and fire extinguishing system comprising such an apparatus are the following.

0069The difficulty of finding the fire extinguisher from as soon as the initial alarm starts in obviously unexpected situations is considerably reduced. Indeed, concomitant events often negatively affect the timeliness of interventions, with a consequent increase of damages or even impossibility to extinguish the fire before it takes uncontrollable proportions.

0070Since the LASER 16 device which emits the light beam 7 is integral with the fire extinguisher 2, the identification of the fire extinguisher 2 itself is facilitated even if the fire extinguisher 2 is removed from its original position indicated by means of the wall signs currently provided and used.

0071In all cases, under poor visibility conditions, the luminous image 9 is more visible than the signs on the wall, thus helping to save time during the minutes of first response to extinguish the fire. The generation of light beam 7 and luminous image 9 may be independent from the environmental conditions where the fire extinguisher is located or may be automatically activated when the ambient light drops below a predetermined threshold value (e.g. because it is dark, because the emergency lighting system has been activated and/or because of the presence of smoke), detected by means of the light sensor 28 (when present).

0072Furthermore, in the presence of smoke, the light beam 7, in addition to the luminous image 9, also becomes particularly well visible.

0073Again, the presence of sound generator 30 and pressure sensor 27 promotes the maintenance of the fire extinguisher 2 under optimal conditions of use, thus allowing to detect possible operating faults and to restore the optimal conditions of use in a timely manner.

0074Furthermore, because the signalling device 3, 3' is directly mounted to the fire extinguisher, in an integrated form with the latter, possible wires coupling or connecting it to a fixed resting station are absent, thus avoiding the risk of creating hindrance for a user of the fire extinguisher 2 and/or of forming sparks which, in a gas saturated environment, could cause an explosion.

0075Finally, the possibility of creating a wireless communication network between the fire extinguishers and with an external control room and/or an operator allows an immediate intervention by a maintenance operator who may restore the correct operation of the fire extinguisher which indicated the fault if even only one fire extinguisher signals a fault event.

0076It is apparent that changes and variants may be made to the position signalling apparatus for fire extinguishers and to the fire extinguishing system herein described and illustrated without therefore departing from the scope of protection of the present invention.

0077For example, several LASER devices 16 (or several LED devices) may be present. Furthermore, any other type of optical or optical-electronic device may be used.

0078The electronic circuit 15, 23, 24 may indifferently comprise all or only some of the energy converter 19, the sensor/indicator block 26, the sound generator 30 and the communication interface 31; similarly, the sensor block 26 may indifferently comprise only one or more of the pressure sensor 27, the light sensor 28, the temperature sensor 29 and the accelerometer 32.

0079Furthermore, the sound generator 30, when used to generate faulty operation sound signals of the fire extinguisher 2, may be installed by the side of an optical faulty operation indicator (e.g. a LED, not shown) to support the sound signalling with an optical signalling.

0080Furthermore, the sound alarm signal may also be generated during the fire to further facilitate finding the fire extinguisher 2.

0081Moreover, the coordinator device 51 may be made in the form of an integrated board adapted to be interfaced with a computer (e.g. by means of a PCI slot, a USB interface or other). In this case, the coordinator device 51 is directly powered by the computer and the video 55 is the monitor of the computer itself.

0082Finally, each fire extinguisher 2, comprising a signalling apparatus 3, 3' including an electronic circuit 24 of the type shown in <figref idref="f0005">figure 7</figref>, and belonging to a fire extinguishing system 50 of the type shown and described with reference to <figref idref="f0006">figure 8</figref>, may store in the memory 25 a history of alarm events occurred in the fire extinguishing system 50. As all fire extinguishers 2 belonging to the fire extinguishing system 50 communicate with one another by means of the signalling apparatus 3, 3', possible alarm and/or malfunction messages related to a fire extinguisher 2 may be transmitted to all signalling apparatuses 3, 3' of the other fire extinguishers 2. Thereby, the alarm history may be retrieved for later analyses of the alarms and/or malfunctions which occurred, even in case of malfunction of the coordinator device 51 or of some signalling apparatuses 3, 3' of the fire extinguishers 2 belonging to the fire extinguishing system 50.

0083The position signalling apparatus for fire extinguishers according to the present invention may be placed on new and old generation fire extinguishers present in industrial buildings, hospitals, schools and in all places specified by the law or regulations of every respective country.