ARRANGEMENTS IN AUDIOVISUAL FIRE DETECTING APPARATUS

Abstract: An electrical, battery-driven audiovisual fire detecting apparatus comprising a smoke/heat detector and a light gleam generating emergency light source electrically interconnected thereto, said source being adapted to generate gleaming or flashing light upon the release of the smoke/heat detector. Said apparatus is mountable outside a sleeping room door. The emergency light source is a flashlight source (20).

Description: ARRANGEMENTS IN AUDIO-VISUAL FIRE DETECTING APPARATUS The present invention relates to arrangements in audiovisual fire detecting apparatus in the form of a smoke/heat alarm device (below designated "smoke detector" only) , and a gleam- generating emergency light source interconnected thereto and adapted to be activated upon the activation of the smoke detector. Upon the emergency light source's activation, the gleams or flashes thereof serve as guide light for socalled "smoke divers" (B.A. men, firemen working in conditions requiring breathing apparatus) in smoke-filled rooms or the like during fire, and the well tested release technique of the smoke detector is, thus, utilized in an advantageous way. Likewise, the invention relates to a special use of a certain light as guiding light for B.A. firemen in smoke-filled rooms during fire. The most typical positioning for such audio-visual fire detecting apparatus is outside a sleeping room, where guide light for rescuers and B.A. firemen attempts to show the way to sleeping people and children unaware of a fire in its starting phase or an ongoing fire, where an enormous development of smoke, especially in the dark, prevents or hampers the sight and sense of direction of the B.A. firemen within the house building. An audio-visual fire detecting apparatus of the kind defined introductorily, is i.a. known from U.S. patent specification No. 5,177,461, where an apparatus has been disclosed, comprising a smoke detector in combination with a light source adapted, upon activation, to transmit flashes or gleams of ordinary, socalled "white" light. The flashing or gleaming light source is adapted to react on the activation of the smoke detector and, thus, utilizes the advantage of the well tested release device thereof, which in a way also acts as a release or activating means for the light source. However, it has been found, particularly in dense smoke, especially in combination with darkness, that such gleams of ordinary light are quite inefficient as guide light for B.A. firemen, the gleams transmitted from the light source tending to form a kind of unconcentrated, outflowing "fog-like light" scattering into areas far outside the light source, where the main task of the latter, namely to make B.A. firemen aware of its positioning for instance just outside a sleeping room, can not nearly be achieved. On the other hand, the B.A. firemen have to search for the location of the light sources on the basis of the diffuse and vague light effect of the light gleams or flashes,resulting in valuable rescue work time being wasted. According to U.S. patent specification No. 5,153,567, a similar gleaming light souce becomes released upon the activation of a fire extinguisher. Thus, a highly undesired delay in the visual fire detecting device occurs, in relation to a gleaming or flashing light source released simultaneously with the assigned smoke detector. From U.S. patent specification No. 4,812,821, a fire detecting apparatus is known, transmitting visual signals in the form of flashing light upon the activation of an interconnected heat/smoke sensing detector. Any information whatsoever is welcome in darkness and dense smoke, but the hitherto known and used flashes or gleams have not, during difficult conditions, especially dense smoke and darkness, had the desired ability of penetrating concentratedly through the smoke, unambiguously pointing out the position of their light source, in order to attract the B.A. firemen to the mounting place of the light source outside a sleeping room door. Light from flash lamps, flash-light, has substantially been used in connection with photography. Thus, it represents a new and particular use according to the present invention to use flash-light as guide light for B.A. firemen in smoke-filled rooms or the like during a fire. It has, namely, surprisingly been found that flash-light created in a desired manner, i.a. on the basis of noble gas (e.g. xenon, crypton) , in a quite outstanding way penetrates thick, dense smoke concentratedly in that respect that the flash-light immediately can be traced back to the flash¬ light source and the position of the latter. The flash-light "cuts", without any undesired diffusion worth mentioning, through dense smoke and lights well up in utter darkness. In an audio-visual fire detecting apparatus of substantially the kind defined introductorily, the present invention consists in that the light source consists of a flash-light- generating means. A typical position for a smoke detector is adjacent the ceiling, e.g. outside a sleeping room door. A flash-light- generating means interconnected with a smoke detector, will suitably be placed outside the sleeping room door, at or adjacent the floor, an electrical conduit connection between the two main components of the audio-visual fire detecting apparatus will, thus, extend itself substantially vertically. Thus, B.A. firemen will save a lot of valuable time in relation to known audio-visual fire detecting systems. Upon the occurence of a small fire, followed by smoke development, the first minutes thereafter are usually the most decisive in respect of rescuring people in a burning building or the like. The invention's field of application is broad and comprises, apart from private residences, hotels, hospitals, old people's houses, ships, etc. The unit according to the invention comprising a means which upon the supply of electrical current is adapted to generate gleaming flash-light, is intended to have a simple construction and, thus, be capable of being delivered at a reasonable price. The unit must be adapted for interconnection with a fire detector/smoke detector of an existing type or any fire detector/smoke detector that might be developed subsequently, and which is subjected to constructive improvements only, without differing from basic principles of structure and function, wherein the release means adapted to react on smoke respectively a certain smoke density in the area of its positioning, and the capability of functioning thereof well tried out in the course of many years, normally will constitute a common release means for the smoke detector and the audio-visual fire detecting apparatus according to the invention. Said unit should contain a xenon flash lamp or another flash-light-generating means and an accumulator battery, e.g. a replaceable 9 volt battery of standard type. Upon the positioning of the audio¬ visual fire detecting apparatus in an area close to the floor, outside a sleeping room door or the like, it will be substantially easier to change the battery there than just beneath the ceiling, the normal mounting place for a smoke detector. However, it will be difficult to achieve e.g. 30 minutes operational time securing efficiently gleaming flash-light from a nearly uncharged battery. Therefore, it is most suitable to construct the unit for connection to a 220 volt installation, the audio-visual fire detecting apparatus being equipped with a plug to be inserted into a socket incorporated in the power supply network. Operating on the basis of a voltage of 220 volt, battery change will become quite superfluous, as the connected fire detector is supplied with electrical current from the unit containing the flash-light source and a chargeable battery. The unit according to the invention may appropriately have a current so large that 2-5 smoke detectors can be operated, simultaneously as the battery is charged. The battery may run continuously on maintenance charge, as it never will be actual to charge a flat battery. Based on quite preliminary estimates, one has calculated that the unit according to the invention is capable of functioning in minimum 30 minutes following power failure. This is decisive for the dimensioning of the battery which is common for the unit according to the invention and the smoke detector connected thereto. The unit according to the invention may have the same size as a double socket, and the frequency of flashing may e.g. be one time per second. To the unit according to the invention, one or more smoke detectors may be coupled. This detector or these detectors, respectively, must be intended for use at 9 volt or 12 volt, respectively, and, if more than one smoke detector is used for each unit, it will be equipped with contacts allowing the smoke detectors to be coupled in series. In order to establish the interconnection, a thin conduit comprising three conductors may be used, of which two conductors are adapted for a voltage supply of 9 volt or 12 volt, respectively, the third conductor generating a signal added to +9 volt or +12 volt, respectively, when a smoke detector is released. The unit according to the invention must be adequately protected against high voltage, as it will arise very high voltages internally within the unit, so that appropriate measures must be taken in order to insulate charged conductors and parts. However, the unit shall normally be opened by a licensed electrician. The output for coupling the smoke detector to the apparatus, must distinguish itself in a satisfactory way from the 220 volt power supply network according to NEMKO's rules and regulations. It is to be expected that an audio-visual fire detecting apparatus in accordance with the invention shall be capable of functioning satisfactorily within a temperature range from about 0 to about 70°C. A non-restricting example of an embodiment of the invention is further explained in the following, reference being made to the accompanying diagrammatical drawing, wherein: Figure 1 shows a highly simplified embodiment, as seen from above in relation to a mounting position (where it is imagined firmly screwed to a wall close to the floor) ; Figure 2 shows the same in a side elevational view. The finished unit will comprise one part including the electronics mounted on an attachment plate and a loose plastic cover 10 having a window put in position when the connections have been established. A bottom plate 12 incorporated within the unit according to the invention has holes 14 for attachment screws (not shown) . The three terminals having screw couplings for the connection of the smoke detector, not shown, are denoted at the reference numeral 16, and the two similar terminals for connection to the power supply network, at 18. A xenon lamp 20 constituting the flash-light source of the unit, should have an extra cover (not shown) to shield against contact when the plastic cover 10 is removed. A print 22 is mounted on spacers 24 of plastic, fastened to the bottom plate 12. Besides, the size and circumference of the unit is decided by the 9 volt accumulator battery's 26 dimensions. The electronics of the unit is very simple. During production it will be suitable to combine all electronics on one print, with both charger and flasher. An appropriate gleaming/ flashing device may consist of a highfrequency DC-DC- converter generating a voltage of about 100-200 volt, and a circuit for discharging e.g. each second through the xenon lamp or a lamp containing another flash-light-generating noble gas. The lamp 20 is released by a very high voltage (several thousand volt) generated by a transformer incorporated into the unit according to the invention.

Claims: C l a i m s 1. Arrangements in an electrical, battery-driven audio¬ visual fire detecting apparatus comprising a smoke/heat detector and a therewith electrically interconnected, light gleam generating emergency light source adapted to be activated and, then, generate gleaming light upon the release of the smoke/heat detector, said fire detecting apparatus, preferably, being intended to be mounted immediately outside a sleeping room or the like, c h a r a c t e r i z e d i n that the emergency light source is a flash-light source (20). 2. Arrangements as set forth in claim 1, c h a r a c t e r i z e d i n that the flash-light source (20) is incorporated within a unit which, moreover, contains an accumulator battery (26) , e.g. a 9 volt battery, said unit comprising terminals (16, 18) for the smoke/heat detector's connection thereto, respectively for the unit's connection to a 220 volt power supply network, and that the accumulator battery (26) is adapted to be subjected to substantially continuous maintenance charging, so that it at any time is completely charged and may function satisfactorily in e.g. minimum 30 minutes after an interruption of current, and wherein the charging circuit may comprise a first transformer, e.g. a miniature transformer in the form of a 220 volt to 2 x 6 volt transformer, as well as a rectifier and a resistance, and wherein measures have been taken in order to separate the output for the smoke/heat detector's connection from the 220 volt network. 3. Arrangements as set forth in claim 2, c h a r a c t e r i z e d i n that to the flash-light source (20) is assigned a flashing unit in the form of a highfrequency DC-DC-converter generating a voltage of about 100-200 volt, a circuit being disposed for effecting discharge through the flash lamp (20), e.g. every second, while release of the flash lamp (20) takes place by means of a very high voltage (several thousand volt) generated by a second transformer. 4. Arrangements as set forth in claims 1 - 3, c h a r a c t e r i z e d i n that two or more smoke/heat detectors are coupled to one unit comprising flash lamp, accumulator battery (26) and terminals (16, 18) for the connection of smoke/heat detectors coupled in series, respectively for connection to a power supply network 220 volt. 5. Arrangements as set forth in any one of the preceding claims, c h a r a c t e r i z e d i n that the electrical connection between the smoke/heat detector and said unit comprising i.a. the flash-light source (20) and the accumulator battery (26) for the audio-visual fire detecting apparatus, in the form of a conduit consisting of three conductors, wherein two of the conductors provide a voltage supply of 9 volt respectively 12 volt, while the third conductor constitutes a signal added to +9 volt respectively +12 volt when the fire detector respectively one (the first) of the fire detectors is released in order to activate the audio-visual fire detecting apparatus, said electrical connection having such a longitudinal extent that it allows the mounting of the smoke/heat detector in or close to the ceiling, e.g. outside a sleeping room door, and said unit, i.e. the rest of the audio-visual fire detecting apparatus, at or adjacent the floor, substantially vertically below the mounting place of the smoke/heat detector. 6. Use of flash-light as emergency/guide light for B.A. firemen in smoke-filled room or the like under circumstances comprising conditions prior to fire or during fire conditions respectively conditions substantially consisting in "abnormal" smoke development, e.g. development of toxic smoke or smoke harmful to the health, without or with sparse development of flames.

Inventors: OLSEN KURT-ARE, OLSEN, KURT-ARE
Applicants: OLSEN KURT ARE, OLSEN, KURT-ARE
Application year: 1997
Main classification: G08B17
IPC codes: G08B7