EP1376505B1 - Fire detector - Google Patents

Abstract

The device has an alarm insert with a sensor arrangement (2) and evaluation electronics and a housing (3) around the sensor arrangement with openings for the entry of air and smoke if appropriate to the sensor arrangement. The device is modular and is designed to accept detection modules with sensors for different fire parameters, whereby all detection modules are compatible with a single housing.

Description

The present invention relates to a fire detector with a detector insert, which has a sensor arrangement and an evaluation, and with a housing surrounding the sensor assembly with openings for the access of room air and possibly smoke to the sensor array.

The sensor arrangement can have, for example, an electro-optical sensor for detecting the scattered light generated by smoke in the ambient air, or a temperature sensor for detecting the heat generated in a fire or a gas sensor for detecting combustion gases or combinations of these sensors. In the fire detectors known hitherto, depending on the sensor arrangement used, both the detector insert and the housing are different, so that a separate injection molding tool is required for each detector type, which increases the production costs. The storage of various types of detector inserts and housings also causes undesirable costs.

The invention will now be a unification of the detector inserts and the housing and thus a reduction in costs are made possible. The aim is that a single housing can be used for different types of detectors.

This object is achieved according to the invention in that the detector has a modular structure and is designed to accommodate detection modules for different fire parameters, all detection modules being compatible with a single housing.

The modular design with a housing and different compatible detection modules results in a universally usable detector with a uniform external appearance. This looks aesthetically pleasing and also causes a noticeable reduction in manufacturing costs.

From WO / 0155991 a modular fire detector is known.

Today, so-called optical-thermal detectors are widely used, which have an electro-optical sensor and a temperature sensor. In these detectors, in most cases the temperature sensor is located at the level below the electro-optical sensor, preferably in the center axis of the detector. In most cases, the above-mentioned access openings are at this lower level. This results in a "multi-level" structure of the detector that determines the detector height. For aesthetic reasons, however, the smallest possible height of the detector is often desired.

Another object of the invention is to provide a fire detector with a compatible with the various detection modules housing of the lowest possible height.

This object is achieved according to the invention in that the sensor arrangement and the said access openings are arranged essentially on one level.

The detector according to the invention is therefore a relatively flat detector which can be used both as a multi-criteria and as a single-criteria detector. The small height of the detector is made possible by the arrangement of the sensor arrangement and the access openings on one level.

The inventive fire detector is also characterized in that the detection modules have a same for all types of detectors and usable in the detector carrier plate, which is designed to receive the sensors for the different fire parameters.

A first preferred embodiment is characterized in that the support plate has on its underside facing the detector tip housing for receiving components of an electro-optical sensor system and is formed on its upper side for mounting a transmitter carrying the transmitter.

A second preferred embodiment of the inventive fire detector is characterized in that the housing has a detector hood, which consists of an annular upper and a spaced from this and forming the tip of the detector lower part. The intermediate space between the two parts of the detector hood forms said access openings and said lower part is connected to the upper part by arcuate or rib-like webs.

A third preferred embodiment is characterized in that an optical detection module is provided for the measurement of smoke-induced scattered light which has at least one light source, a light receiver, a measuring chamber and a labyrinth system with diaphragms arranged on the periphery of the measuring chamber, wherein the at least one Light source and the light receiver are mounted in the housings on the underside of the support plate and the labyrinth system formed lid-like and can be fixed on the support plate.

A further preferred embodiment is characterized in that a thermal detection module is provided with two temperature sensors which are mounted radially opposite each other on the circuit board and protrude from the latter through the support plate downwards. A development of this embodiment is characterized in that the said webs are formed in the form of wings or tabs with a vertically extending recess and provided in an even number, and that the temperature sensors in such a way each protrude from above against one of the webs that their free ends are directly in or behind the recess. The thermal detection module has a cover plate which can be fixed on the carrier plate for covering the housing provided for the electro-optical sensor system, and openings for the passage of the temperature sensors and a partition wall extending radially between the temperature sensors for obtaining a directed air flow are provided on the cover plate.

A further preferred embodiment of the inventive fire detector is characterized in that an optical-thermal detection module for the measurement of scattered light caused by smoke and for temperature measurement is provided which has an electro-optical sensor system and two temperature sensors, the latter being arranged laterally next to the optical sensor system ,

According to a development of this preferred embodiment, the temperature sensors are mounted radially opposite each other on the circuit board and lie with their free ends in the region of one of said webs. Preferably, the webs are formed so as to protect the one hand, the temperature sensors from mechanical effects and on the other hand to ensure the most undisturbed air flow of the temperature sensors.

Fig. 1

eine perspektivische Darstellung eines ersten Ausführungsbeispiels eines erfindungsgemässen Melders von vorne unten gesehen,

Fig. 2

eine perspektivische Darstellung eines Querschnitts durch den Melder von Fig. 1,

Fig. 3

eine perspektivische Darstellung eines Axialschnitts durch den Melder von Fig. 1,

Fig. 4

eine Draufsicht auf den Melder von Fig. 1,

Fig. 5

eine perspektivische Darstellung einer Draufsicht auf den Melder von Fig. 1 ohne Sockel aber mit Sockelklemme,

Fig. 6

eine perspektivische Darstellung eines zweiten Ausführungsbeispiels eines erfindungsgemässen Melders von vorne unten gesehen,

Fig. 7

eine perspektivische Ansicht des Melder von Fig. 6 bei abgenommener Melderkuppe von unten gesehen; und

Fig. 8

eine perspektivische Darstellung eines Axialschnitts durch den Melder von Fig. 6.

In the following the invention will be explained in more detail with reference to embodiments and the drawings; it shows:

Fig. 1

a perspective view of a first embodiment of an inventive detector seen from the front bottom,

Fig. 2

3 a perspective view of a cross section through the detector of FIG. 1,

Fig. 3

3 a perspective view of an axial section through the detector of FIG. 1,

Fig. 4

a top view of the detector of Fig. 1,

Fig. 5

1 is a perspective view of a plan view of the detector of Figure 1 without socket but with base terminal.

Fig. 6

a perspective view of a second embodiment of an inventive detector seen from the front bottom,

Fig. 7

a perspective view of the detector of Figure 6 with the detector tip removed from below. and

Fig. 8

a perspective view of an axial section through the detector of Fig. 6.

The smoke detector shown in Figures 1 to 5 consists in a known manner of three main components, a base 1, an optical sensor system 2 and a housing 3. This structure is best seen in Fig. 3. FIG. 2 shows a view of a part of the optical sensor system 2 in a cross section through the detector as seen from below.

The base 1 is intended for mounting on the ceiling of the room to be monitored, with the installation either directly on a flush box or surface-mounted with or without socket addition he follows. The base 1, which essentially consists of a circular plate and a downwardly projecting edge web, contains inter alia a plug connector 4 (FIGS. 3, 4) which is provided for receiving a contact strip 5 (FIG. 4) connected to the sensor system ,

The optical sensor system 2 includes a plate-shaped carrier 6 for the optical sensor, a fixed to the underside of the carrier 6 lid-shaped labyrinth 7, arranged on the base 1 facing the upper side of the carrier 6 arranged circuit board 8 with the transmitter and a printed circuit board 8 am Edge and upwardly covering cover 9, which forms part of the housing 3. The contact strip 5 is an integral part of the support plate 6 and protrudes from this upwards. The cover 9 has substantially the shape of a plate with a peripheral collar at the edge and with an opening 10 for the passage of the contact strip 5, so that this projects into the plane of the socket 1 arranged in the socket strip 4.

The optical sensor shown in FIG. 2 includes a measuring chamber formed by the carrier 6 and the labyrinth 7 with a light receiver 11 and two light sources 12, 12 ', which are each arranged in a housing 13, 14, 15. These housings consist of a bottom part, in which the respective diode (photodiode or IRED) is held, and which has a window opening for the entrance or exit of light at its front side facing the center of the measuring chamber. As can be seen from the figure, the scattering space formed in the measuring chamber in the region in front of the mentioned window-like openings of the housings 13, 14, 15 is compact and exposed. This arrangement and shape makes the detector for the use of a usable in this scattering space transparent body for smoke simulation best suited. Such transparent bodies are used to adjust or test for smoke sensitivity in the manufacture of the detectors (see EP-B-0 658 264).

The frames of the window openings are integrally formed at least in the housings 14 and 15, whereby the tolerances for the smoke sensitivity are reduced. In known scattered light smoke detectors, the window frames consist of two parts, one of which is worked on the ceiling and the other at the bottom of the measuring chamber. When putting the floor pass difficulties occur again and there are variable window sizes and the formation of a gap between the two halves of the window and thus undesirable interference of the transmitting and the receiving light. In the one-piece housing windows disturbances of this kind are excluded and there can be no problems with the positioning accuracy of window halves. The windows are rectangular or square and between the window openings and the associated light source 12, 12 'and the lens of the associated light receiver 11 is a relatively large distance, resulting in a relatively small opening angle of the respective light beams. A small opening angle of the light beams has the advantage that, on the one hand, hardly any light of the light sources 12, 12 'hits the ground and, on the other hand, the light receiver 11 does not "see" the ground, so that dust particles deposited on the floor can not produce disturbing scattered light. Another advantage the large distance between the windows and the light source 12, 12 'and the lens of the light receiver 11 is that the penetrated by light optical surfaces are relatively deep inside the housing and are thus well protected against contamination, resulting in a constant sensitivity of opto result in electronic elements.

The labyrinth 7 consists of a bottom and peripherally arranged aperture 16 and it contains flat cover for said housing 13, 14, 15. The bottom and the panels 16 serve to shield the measuring chamber against extraneous light from the outside and to suppress the so-called background light ( see also EP-A-0 821 330 and EP-A-1 087 352).

The peripherally arranged aperture 16 each consist of two legs and have an L-shaped configuration. Due to the shape and arrangement of the aperture 16, in particular by their mutual distance, it is ensured that the measuring chamber is adequately shielded from extraneous light and still their function can be checked with an optical test device (EP-B-0 636 266). In addition, the panels 16 are arranged asymmetrically, so that smoke from all directions can penetrate similarly well into the measuring chamber.

The directed against the measuring chamber leading edge of the aperture 16 is formed as sharp as possible, so that only a little light fall on such an edge and can be reflected. Floor and ceiling of the measuring chamber, so the facing surfaces of the carrier 6 and the labyrinth 7, are fluted, and all surfaces in the measuring chamber, in particular the aperture 16 and the said fluted surfaces are shiny and act like black mirrors. This has the advantage that incident light is not diffusely scattered but reflected directionally.

The arrangement of the two light sources 12 and 12 'is selected so that the optical axis of the light receiver 11 with the optical axis of the one light source, according to the light source 12, a blunt and with the optical axis of the other light source, according to the light source 12', includes an acute angle. The light of the light source 12, 12 'is scattered by smoke entering the measuring chamber and a portion of this scattered light is incident on the light receiver 11, with an obtuse angle between the optical axes of light source and light receiver of forward scattering and at an acute angle between the light source optical axes of backward scattering speaks.

It is known that the scattered light generated by forward scattering is substantially larger than that produced by backward scattering, the two scattered light portions being characteristically different for different types of fires. This phenomenon is known, for example, from WO-A-84/01950 (= US Pat. No. 4,642,471), which discloses, inter alia, that the ratio of scattering at a small scattering angle to scattering at a larger scattering angle is different for different types of smoke Make use of the smoke type detection. The larger spread angle can also be chosen over 90 ° so that the forward angle and the backward scatter is evaluated. The evaluation of the scattered light components originating from the two light sources 12 and 12 'does not form the subject of the present application and will therefore not be described in more detail here.

For better discrimination between different aerosols can be provided in the beam path transmitter and / or receiver side active or passive polarizing filter. The carrier 6 is prepared accordingly and has provided in the housings 13, 14 and 15 grooves (not shown) in which polarizing filter can be fixed. As a further option, as light sources 12, 12 'diodes can be used, which emit radiation in the wavelength range of visible light (see EP-A-0 926 646), or the light sources can emit radiation of different wavelengths, for example the one light source red and the other blue light.

The housing 3 of the smoke detector is constructed substantially in two parts and consists of the already mentioned cover 9 and a sensor sensor system 2 comprehensive detector hood 17. The latter consists of an upper annular portion and a spaced therefrom, the tip of the detector forming plate which is connected to the upper annular part by arcuate or rib-like webs 18. The space designated by the reference numeral 19 between the upper and the lower part of the detector hood 17 forms a running over the entire housing circumference opening for the entry of air and thus smoke to the optical sensor system 2, said opening is interrupted only by the relatively narrow webs 18 , There is an even number of webs 18 is provided, according to four.

The detector hood 17 and the cover 9 are fixed to the carrier 6 via hook-type snap fasteners (not shown) and the entire detector is fastened in the base 1. In the upper part of the detector hood 17, a ring 20 is inserted, which carries an insect screen 21 made of a suitable flexible material. When attaching the detector hood 17, the carrier 6 is pressed against the ring 20, whereby the insect screen 21 is fixed in the detector. The attachment of the detector in the base 1 is done by a kind of bayonet lock. The detector is pushed from below into the base 1, which is possible due to a formed by guide ribs and grooves mechanical coding only in a single relative position between the detector and socket. Then, the detector in the base 1 is rotated by an angle of about 20 ° (Fig. 4), whereby the part of the carrier 6 forming and projecting upwardly from this contact strip 5 inserted tangentially into the socket strip mounted in the socket 1 and the electrical contact between the connector strip 4 and the contact strip 5 and thus between the detector and socket is made. Subsequently, the mechanical fixation of the detector in the base 1 is effected by the aforementioned bayonet closure.

The contact strip 5 is integrated on the upper side of the carrier 6 in so-called insert technique and manufactured in one piece with the carrier 6. Of the plug contacts of the contact strip 5, the electrical connections are made to a cast into the carrier 6 stamped part with metallic, mutually insulated metal conductors. The free ends of these metal conductors protrude next to the contact strip 5 from the carrier 6 and form contact points for the production of solder joints to the transmitter on the circuit board. 8

• Für die Herstellung der Steckverbindung ist nur eine einfache Mechanik erforderlich und es muss insbesondere keine Umsetzung einer Rotations- in eine Translationsbewegung erfolgen.
• Die kompakte Steckverbindung erlaubt einfache Schlaufkontakte und besitzt ausgezeichnete Eigenschaften hinsichtlich elektro-magnetischer Verträglichkeit (EMV).

The electrical connection between detector and socket through the two elements connector strip 4 and contact strip 5 has a number of advantages:

• For the production of the connector only a simple mechanism is required and there must be no particular implementation of a rotational in a translational movement.
• The compact connector allows simple loop contacts and has excellent properties with regard to electro-magnetic compatibility (EMC).

As can be seen from Fig. 3, a light guide 22 is fixed to the bottom of the labyrinth 7 forming member, which projects on the one hand up to the circuit board 8 and on the other hand through a hole in the lower part of the detector hood 17 from the detector hood. The detector hood is provided in the region of said bore with a spherical recess 23 which surrounds the free end of the light guide 22. The light guide 22 serves as a so-called alarm indicator for the visual display of alarm conditions of the detector. On the circuit board 8, an LED (not shown) is provided for this purpose, which is activated in an alarm condition and the light guide 22 is exposed to light.

If a detector sends an alarm signal, then it is usually a visual check whether the alarm indicator also indicates an alarm. It is clear that the alarm indicator should be visible on all sides for this check. Where this is not the case, the detectors must be mounted in the interstitial space so that the alarm indicator is clearly visible from the door. For purely thermal detectors where there are no restrictions on the location of the alarm indicator due to the lack of an optical sensor, the alarm indicator is often located at the detector apex (see US-A-5 450 066). In the case of scattered light smoke detectors, this is only possible with restrictions because, on the one hand, a light guide guided in the detector axis and thus through the scattering space is out of the question and therefore a curved light guide would have to be used and, on the other hand, the electrical connection to a LED mounted on the detector apex would be too costly. For this reason, the alarm indicator is usually located at the periphery of the detector in scattered light smoke detectors (see DE-A-100 54 111) and practically visible only from a very small solid angle, resulting in the already mentioned problems with respect to installation and positioning of the detectors leads. Proposals for an all-round visibility of the alarm indicator in scattered light smoke detectors are in the direction of ring-shaped or strip-shaped light guides over the entire circumference of the detector hood (EP-1 049 061). However, these solutions are not satisfactory, because a light guide with such a large luminous area requires a relatively large amount of power so that it lights up sufficiently bright to ensure reliable detection of alarm displays.

The alarm indicator requires little power and, because it is located in the area of the detector apex, it is practically visible on all sides. The visibility from all sides is only given from a viewing angle of 20 ° to the horizontal, but since the detector is mounted on the ceiling, this condition is met in most cases. As can be seen in particular from FIG. 2, the light guide 22 is guided through the measuring chamber in the area between the housings 14 and 15. The two housings 14 and 15 are connected to one another at their front side and thus form, with their inner side surfaces and the connecting surface between them, a wall surrounding the optical waveguide 22 which largely shields the scattering space of the measuring chamber from the optical waveguide 22.

The smoke detector described so far is a purely optical detector with smoke detection based on the scattered light caused by smoke particles that have penetrated into the measuring chamber. Optionally, the detector can be designed as a two-criteria detector and additionally contain a temperature sensor. According to FIGS. 1 and 2, two temperature sensors 24 formed by NTC resistors are provided, which are arranged in the region of two mutually opposite webs 18. The webs 18 have in the middle of an elongated recess 25, in which from above the temperature sensors 24 protrude, which are mounted on the circuit board 8. Optical thermal detectors are known, so that a description of the signal evaluation is omitted here. Of course, the detector could contain other sensors, such as a fire gas sensor (CO, NO _x ), which could be arranged at correspondingly small dimensions within the measuring chamber.

The smoke detector described so far is a purely optical detector with smoke detection based on the scattered light caused by smoke particles that have penetrated into the measuring chamber. Optionally, the detector can be designed as a two-criteria detector and additionally contain a temperature sensor. According to FIGS. 1 and 2, two temperature sensors 24 formed by NTC resistors are provided, which are arranged in the region of two mutually opposite webs 18. The webs 18 have in the middle of an elongated recess 25, in which from above the temperature sensors 24 protrude, which are mounted on the circuit board 8. Optical thermal detectors are known, so that a description of the signal evaluation is omitted here. Of course, the detector could contain other sensors, such as a fire gas sensor (CO, NO _x ), which could be arranged at correspondingly small dimensions within the measuring chamber.

While arranged in the axis of the detector temperature sensors are completely independent of direction, there is a strong directional dependence in a peripherally arranged sensor and the response depends on whether the sensor is located on the side facing the fire or on the side facing away from the detector. This problem is solved by the use of two opposing temperature sensors 24. For details, in the description of Figures 6 to 8. It is essential that the detector has a homogeneous, rotationally symmetrical sensitivity regardless of the direction of flow. This is achieved by the webs 18 in cooperation with the labyrinth 7, wherein the webs 18 on the one hand protect the temperature sensors 24 against mechanical forces and optimally direct the air to the sensors and on the other hand in cooperation with the labyrinth 7 outside the air along the housing along.

As already mentioned in the introduction to the introduction, optical, optical-thermal and thermal fire detectors are in use today, whereby gas detectors can still be used for these. In addition, the optical, thermal and optical thermal detectors may additionally have a fire gas sensor. The detector shown in FIGS. 1 to 5 covers the variants visually and optically-thermally (possibly supplemented by a fire gas sensor), wherein of course in the purely optical detector no temperature sensors 24 are provided. Apart from that, but the detector structure in the two variants previously described mechanically completely the same.

As will now be explained with reference to FIGS. 6 to 8, the detector can also serve as the basis for a purely thermal detector without any conceptual changes to the base or housing. Since the mechanical main components and the structure of the detector are always the same in all cases, a family of fire detectors with sensors for different fire characteristics is proposed, which manages with a single, in all cases the same housing and a single base and thus allows substantial savings.

• Die Lichtquellen 12 und 12' und der Lichtempfänger 11 sind weggelassen,
• der Ring 20 und das Gitter 21 sind weggelassen,
• das Labyrinth 7 ist weggelassen und durch eine Abdeckplatte 26 ersetzt.

The thermal fire detector shown in FIGS. 6 to 8 differs essentially from the optical-thermal detector shown in FIGS. 1 to 5 by the following features:

• The light sources 12 and 12 'and the light receiver 11 are omitted,
• the ring 20 and the grid 21 are omitted,
• the labyrinth 7 is omitted and replaced by a cover plate 26.

The cover plate 26 is a very essential part of the thermal fire detector because, among other things, it allows one and the same support 6 to be used for the different types of detectors. As can be seen in particular from Fig. 7, which shows a view of the cover plate 26 from below, this has the contour of the housing 13, 14 and 15 adapted openings through which said housing with their lower ends protrude. In addition, elastic tongues 27, 28 and 29 are provided on the cover plate 26, which serve to cover the housing 13, 14, 15 and are snapped into this. In addition, the cover plate 26 has a tubular holder 30 for the light guide 22, two openings for the temperature sensors 24 and extending therebetween a partition wall 31, which serves to achieve a directed air flow.

The partition wall 31 makes a significant contribution to the fact that the described thermal fire detector has a homogeneous sensitivity and meets the strict requirements of the standard EN 54/5, class A1. Together with the webs 18, the dividing wall 31 directs the incoming air through the housing to the sensors 24.

When evaluating the signals of the two temperature sensors 24, one can either take into account the higher value or the mean value, but one can also weight both values and use them together for the evaluation. The response of the temperature sensors provides an indication of the location of the fire, assuming that the fire is on the detector side with the higher temperature sensor.

Another advantage of using two temperature sensors 24 is the associated redundancy. The two sensors monitor each other and drift or aging are noticeable much earlier than with just one sensor. The monitoring of both sensors over a longer period of time must result in both about the same temperature. If not, one of the sensors has a fault.

In the optical-thermal detector shown in Figures 1 to 5 can be achieved by using a double-photodiode as a light receiver 11 optimal redundancy (two light transmitter, two light receivers, two temperature sensors).

• Alle Melder sehen gleich aus, zumindest dann, wenn man sie aus dem üblichen Abstand von mehr als 2 m betrachtet;
• die Melder sind flach und "einstöckig";
• die Melder sind modular aufgebaut und damit kostengünstig herstellbar.

FIGS. 1 to 8 do not show a single detector but a detector system, which is distinguished by three main features:

• All detectors look the same, at least when viewed from the usual distance of more than 2 meters;
• the detectors are flat and "one-story";
• the detectors have a modular structure and can therefore be produced cost-effectively.

Each detector of the system, regardless of whether single or Mehrkriterien-, whether optical or thermal detector has the same base 1, the same housing 3 and the same carrier 6. The individual detectors differ only in the detection module, which is the respective sensor array. The detection module for an optical detector consists of the support 6, the optoelectronic elements 11, 12, 12 ', the labyrinth 7 and the grid 21 with the ring 20, the detection module for a thermal detector from the support 6, the thermal sensors 24 and Cover plate 26, and the detection module for an optical-thermal detector the carrier 6, the opto-electronic elements 11, 12, 12 ', the labyrinth 7, the grid 21 with the ring 20 and the thermal sensors 24, wherein of course the circuit board 8 is also specific to the detector type.

As an additional detection module such is possible for a gas detector, the sensor in question would also be mounted on the support 6 if possible. Another possibility is to arrange the gas sensor laterally next to the fire detector or in a separate, remote from the detector and preferably arranged laterally next to this or molded onto this, housing. Options for further modules include, for example, a module for measuring the radiation power, a camera, or an alarm module with an acoustic alarm transmitter (see EP 01 128 683.8).

Claims (14)

1. Fire detector with a detector insert, which has a sensor arrangement (2) and evaluation electronics, and with a housing (3) surrounding the sensor arrangement (2) with openings for the access of air and, if applicable, smoke to the sensor arrangement (2), characterized in that the detector is of a modular construction and designed for receiving detection modules with sensors (11, 12, 12'; 24) for different fire parameters, all the detection modules being compatible with a single housing (3), in that the sensor arrangement (2) and the said access openings are arranged essentially on one level, and in that the detection modules have a carrier plate (6), which is the same for all types of detector, can be inserted into the detector and is designed for receiving the sensors (11, 12, 12'; 24) for the various fire parameters.
2. Fire detector according to Claim 1, characterized in that the carrier plate (6) has on its underside, facing the detector dome, housings (13, 14, 15) for receiving components of an electrooptical sensor system (2) and is designed on its upper side for the mounting of a printed circuit board (8) carrying the evaluation electronics.
3. Fire detector according to Claim 2, characterized in that the housing (3) has a detector shroud (17), which comprises an annular upper part and a lower part, which is spaced apart from the latter and forms the dome of the detector.
4. Fire detector according to Claim 3, characterized in that the intermediate space (19) between the two parts of the detector shroud (17) forms the said access openings, and the said lower part is connected to the upper part by arcuate or rib-like webs (18).
5. Fire detector according to one of Claims 2 to 4, characterized in that an optical detection module for the measurement of scattered light caused by smoke is provided, having at least one light source (12, 12'), a light receiver (11), a measuring chamber and a labyrinth system (7) with diaphragms (16) arranged at the periphery of the measuring chamber, the at least one light source (12, 12') and the light receiver (11) being fastened in the housings (14, 15; 13) on the underside of the carrier plate (6) and the labyrinth system (7) being formed in the manner of a cover and able to be fixed on the carrier plate (6).
6. Fire detector according to one of Claims 2 to 5, characterized in that a thermal detection module is provided, with two temperature sensors (24), which are fastened on the printed circuit board (8) lying radially opposite each other and protrude downwards from the latter through the carrier plate (6).
7. Fire detector according to Claims 4 and 7, characterized in that the said webs (18) are designed in the form of wings or brackets with a vertically running clearance (25) and are provided in an even number, and in that the temperature sensors (24) protrude from above in each case towards one of the webs (18) in such a way that their free ends lie directly in or behind the clearance (25).
8. Fire detector according to Claims 2 and 7, characterized in that the thermal detection module has a cover plate (26), which can be fixed on the carrier plate (6), for covering the housings (13, 14, 15) provided for the electrooptical sensor system (2), and in that provided on the cover plate (26) are openings for the temperature sensors (24) to pass through and also a dividing wall (31), running between the temperature sensors (24) in a radial direction to achieve a directed air flow.
9. Fire detector according to one of Claims 2 to 4, characterized in that an optical-thermal detection module for the measurement of scattered light caused by smoke and for temperature measurement is provided, which module has an electrooptical sensor system (2) and two temperature sensors (24), the latter being arranged laterally alongside the optical sensor system (2).
10. Fire detector according to Claim 9, characterized in that the temperature sensors (24) are fastened on the printed circuit board (8) lying radially opposite one another and lie with their free ends in the region of one of the said webs (18) .
11. Fire detector according to Claim 7 or 10, characterized in that the webs (18) are formed in such a way that on the one hand they protect the temperature sensors (24) from mechanical effects and on the other hand they ensure that the temperature sensors (24) are subjected to an air flow that is as undisturbed as possible.
12. Fire detector according to Claims 2 and 3, characterized in that fastened on the bottom of the labyrinth system (7) is a light guide (22), which is made to extend upwards to the printed circuit board (8) and forms part of an alarm indicator that can be seen in the region of the apex of the detector.
13. Fire detector according to one of Claims 1 to 14, characterized by a base (1) with a multi-pin connector strip (4), which is assigned to the fire detector, and by a contact strip (5), which is arranged in the fire detector and can be pushed tangentially into the connector strip (4) by turning the detector relatively with respect to the base (1).
14. Fire detector according to Claims 4 and 15, characterized in that the contact strip (5) is integrated on the carrier plate (6) by the insert technique.

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