EP0040342B1 - Smoke detector - Google Patents

Smoke detector Download PDF

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Publication number
EP0040342B1
EP0040342B1 EP81103313A EP81103313A EP0040342B1 EP 0040342 B1 EP0040342 B1 EP 0040342B1 EP 81103313 A EP81103313 A EP 81103313A EP 81103313 A EP81103313 A EP 81103313A EP 0040342 B1 EP0040342 B1 EP 0040342B1
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EP
European Patent Office
Prior art keywords
smoke
smoke detector
measuring chamber
openings
housing
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EP81103313A
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German (de)
French (fr)
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EP0040342A1 (en
Inventor
Andreas Dr. Rer. Nat. Scheidweiler
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Cerberus AG
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Cerberus AG
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Priority to AT81103313T priority Critical patent/ATE25438T1/en
Publication of EP0040342A1 publication Critical patent/EP0040342A1/en
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    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B17/00—Fire alarms; Alarms responsive to explosion
    • G08B17/10—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B17/00—Fire alarms; Alarms responsive to explosion
    • G08B17/10—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means
    • G08B17/11—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means using an ionisation chamber for detecting smoke or gas
    • G08B17/113—Constructional details

Definitions

  • the invention relates to a smoke detector, the type defined in the preamble of claim 1.
  • Such a smoke detector is known from the bulletin of the Swiss Electrotechnical Association dated November 15, 52 (year 43, page 933). These smoke detectors are usually attached to the ceiling with a base plate.
  • Smoke detectors have proven particularly useful for detecting fires at an early stage because they respond to a fire parameter that occurs very early. In order to respond to a smoke detector, it is necessary that smoke, or physically a fire aerosol, penetrates the smoke detector. Transport problems play an important role here. The occurrence of smoke at the fire site is not sufficient to trigger the smoke detector and trigger an alarm. This also requires that a sufficient amount of smoke is transported into the measuring chamber of the smoke detector. The smoke or aerosol particles can then be detected in the measuring chamber in a known manner, e.g.
  • the scattered light optical smoke detector
  • ionization fire detector ionization fire detector
  • other methods e.g. measuring the change in conductivity, humidity or ion density of the room air.
  • the energy required to transport the smoke into the measuring chamber is in most cases supplied by the heat generated during the oxidation.
  • the measuring chamber is largely closed in order to eliminate the influence of stray light as far as possible.
  • a scatter cover is provided in the scattered light smoke detector of JP-A 52-133 797, which automatically closes the smoke entry openings as soon as the signal emitted by the photodetector exceeds a predetermined threshold value. If the signal was caused by stray light, an alarm is suppressed and the smoke inlets are automatically opened again to make the detector ready for operation again.
  • the main aim was to make the measuring chamber largely open to the surrounding atmosphere in order to achieve unimpeded entry of the fire aerosol.
  • the measuring chamber is separated from the outside atmosphere only by a lattice-like hood or a hood with relatively large lattice-like openings.
  • a major disadvantage of the previously known smoke detectors is that specially adapted detectors have to be developed for each area of application in order to ensure that the fire aerosols enter the fire detector optimally for different environmental conditions. This leads to complex manufacturing methods, an unnecessarily large inventory and unnecessary replacement of the detector inserts when the environmental conditions change at the place of use (elimination or Occurrence of dust, etc.).
  • the object of the invention is to eliminate the disadvantages of the previously known smoke detectors and, in particular, to create a smoke detector which can be easily adapted to different environmental conditions. It is also an object of the invention to enable in a structurally simple manner that the smoke detectors allow optimal entry of fire aerosol into the smoke measurement chamber under the respective environmental conditions while at the same time optimally preventing the occurrence of dust.
  • the adjusting device is designed such that the openings can only be changed by means of a special tool.
  • the annular slot is divided into an inner and an outer part by an annular web and the adjusting device is designed such that it changes the outer part of the annular slot. Further refinements of the adjusting devices are designed such that they change the inner part alone or simultaneously the inner and outer part of the annular slot.
  • a further preferred embodiment of the smoke detector according to the invention is that the adjustment device is set up in such a way that it can be changed in stages and that a marking device is provided on which the adjustment of the adjustment device can be read from the outside.
  • the ionization fire detector shown in Fig. 1 consists of a base part 1 and a detector insert 2.
  • the base part 1 has a recess on the side, which an alarm indicator lamp 3, e.g. contains a light emitting diode.
  • the detector insert 2 has a housing consisting of a cylindrical or slightly conical sleeve 4 and a lower cover 5. Between the sleeve 4 and the cover 5 there is an annular slot 13 for the entry of air into the interior of the housing.
  • a cylindrical web 12 is provided on the inside of the cover, by means of which the inflowing air is braked and blocked before it is conducted into the interior of the housing.
  • a carrier plate 6 made of insulating material is attached to the inside of the housing, on which all other components are mounted.
  • a central bore contains a metal stamp 7, which carries a disk-shaped electrode 8 with a radioactive preparation 9.
  • the center electrode 8 and the counter electrode 11 define the ionization chamber 10.
  • a known electrical circuit for evaluating the change in ion current of the chamber 10 can be attached, which can contain a reference ionization chamber which is almost completely sealed off from the outside atmosphere and which is produced in series in a known manner is connected to the ionization chamber 10.
  • the cover 5 of the housing is advantageously designed to be removable from the sleeve 4 in order to facilitate cleaning.
  • Figure 2 shows a section of a further embodiment of a fire detector with the same technical advantages, in which there is a projection 16 on the inner wall of the housing 4, which ensures a further deflection of the incoming air.
  • a displaceable cylinder 17 is located on the inside of the web 12, which either adheres to the inner wall of the cylindrical web 12 by a certain preload, or which springs (not shown) at several points on the outside of the circumference Web 12 is attached.
  • the inner inlet opening 20 of the smoke detector is changed by axially displacing the cylinder 17.
  • 12 grooves can be provided on the inside of the web, engage in the corresponding projections of the cylinder 17, or corresponding grooves can be provided on the outside of the web 12, in which corresponding projections of the fastening springs engage.
  • Figure 3 shows a section of the cross section of a further embodiment of a fire alarm with the same technical advantages, in which on the inside of the sleeve 4, a projection 16 is attached, the one causes further deflection of the incoming air.
  • a projection 16 is attached, the one causes further deflection of the incoming air.
  • grooves are provided on the web, in which corresponding projections of the cylinder ring 18 can engage.
  • the outer inlet opening 13 is changed simultaneously by the flange 19 and the inner inlet opening 20 by the upper edge of the cylinder ring 18.
  • fire detectors with an outer and inner part serving for air deflection for example the fire detector according to CH-PS 475 614, can also be designed in such a way that either the openings of the outer or inner part of the casing are made by a mechanical adjusting device can be changed.

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  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Fire-Detection Mechanisms (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)
  • Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
  • Plural Heterocyclic Compounds (AREA)
  • Fats And Perfumes (AREA)
  • Fire Alarms (AREA)

Abstract

A smoke detector containing at least one smoke measuring chamber which possesses a mounting or socket plate having an upper surface intended to be mounted at the ceiling of a room or other appropriate area to be monitored and a housing enclosing the smoke measuring chamber and suspendingly secured at the socket plate. The housing possesses openings for the entry of the ambient air into the smoke measuring chamber. The smoke detector comprises a manually adjustable device by means of which it is possible to change the air entry opening in a manner such that the smoke detector can be accommodated to different environmental or ambient conditions, especially those containing different quantities of dust and other contaminants. A hood ring member, movably supported at the inside of a sleeve member of the smoke detector, can be selectively displaced in order to change the air entry openings.

Description

Die Erfindung geht aus von einem Rauchmelder, der im Oberbegriff des Patentanspruch 1 definierten Gattung.The invention relates to a smoke detector, the type defined in the preamble of claim 1.

Ein solcher Rauchmelder ist aus dem Bulletin des schweizerischen elektrotechnischen Vereins vom 15.11.52 (43. Jahrgang, Seite 933) bekannt. Diese Rauchmelder sind üblicherweise mit einem Sockelteller hängend an der Raumdecke befestigt.Such a smoke detector is known from the bulletin of the Swiss Electrotechnical Association dated November 15, 52 (year 43, page 933). These smoke detectors are usually attached to the ceiling with a base plate.

Bei der Branddetektion kommt es darauf an, Brände möglichst im Frühstadium zu erkennen, um durch raschen Einsatz von Löschkräften grösseren Schaden zu verhüten und Bewohner rechtzeitig zu warnen. Bei Bränden im Frühstadium, d.h. wenn schwelende Brandherde vorhanden sind, treten häufig toxische Gase und Dämpfe auf, die Menschenleben bereits gefährden, ehe offene Flammen auftreten.When it comes to fire detection, it is important to detect fires as early as possible in order to prevent greater damage by quickly using extinguishing forces and to warn residents in good time. In early stage fires, i.e. If smoldering sources of fire are present, toxic gases and vapors often occur that endanger human life before open flames occur.

Zur Erkennung von Bränden im Frühstadium haben sich Rauchmelder besonders bewährt, da sie auf eine Brandkenngrösse ansprechen, die bereits sehr frühzeitig auftritt. Für das Ansprechen eines Rauchmelders ist es erforderlich, dass Rauch, bzw. physikalisch ausgedrückt ein Brandaerosol, in den Rauchmelder eindringt. Dabei spielen Transportprobleme eine wesentliche Rolle. Das Auftreten von Rauch am Brandort genügt nicht zum Ansprechen des Rauchdetektors und zur Auslösung eines Alarmes. Dazu ist ausserdem notwendig, dass eine ausreichende Menge von Rauch in die Messkammer des Rauchdetektors transportiert wird. In der Messkammer können die Rauch- oder Aerosolteilchen dann in bekannter Weise nachgewiesen werden, z.B. mittels des in einem von einer Lichtquelle ausgehenden Strahlenganges auftretenden Streulichtes (optischer Rauchmelder) oder mittels der Aenderung des Stromes in einer lonisationskammer (lonsiationsfeuermelder) oder auch durch andere Methoden, z.B. die Messung derAenderung der Leitfähigkeit, der Feuchtigkeit oder der lonendichte der Raumluft. Die für den Transport des Rauchs in die Messkammer erforderliche Energie wird in den meisten Fällen durch die bei der Oxydation entstehende Wärme geliefert.Smoke detectors have proven particularly useful for detecting fires at an early stage because they respond to a fire parameter that occurs very early. In order to respond to a smoke detector, it is necessary that smoke, or physically a fire aerosol, penetrates the smoke detector. Transport problems play an important role here. The occurrence of smoke at the fire site is not sufficient to trigger the smoke detector and trigger an alarm. This also requires that a sufficient amount of smoke is transported into the measuring chamber of the smoke detector. The smoke or aerosol particles can then be detected in the measuring chamber in a known manner, e.g. by means of the scattered light (optical smoke detector) occurring in a beam path emanating from a light source or by means of changing the current in an ionization chamber (ionization fire detector) or also by other methods, e.g. measuring the change in conductivity, humidity or ion density of the room air. The energy required to transport the smoke into the measuring chamber is in most cases supplied by the heat generated during the oxidation.

In zahlreichen Patentschriften wurden die beiden hauptsächlich verwendeten Detektortypen immer wieder abgewandelt, um sie speziellen Anwendungsbereichen oder speziellen Anforderungen anzupassen. Aus der Vielzahl der Patentschriften sollen hier nur die CH-PS 264 020, die CH-PS 468 683 und die CH-PS 508 251 für lonisationsbrandmelder und die CH-PS 417 405 und CH-PS 592 932 für optische Rauchmelder genannt werden.In numerous patents, the two types of detectors that are mainly used have been modified time and again to adapt them to specific areas of application or special requirements. From the large number of patents, only CH-PS 264 020, CH-PS 468 683 and CH-PS 508 251 for ionization fire detectors and CH-PS 417 405 and CH-PS 592 932 for optical smoke detectors are to be mentioned here.

Bei optischen Rauchmeldern ist die Messkammer weitgehend geschlossen, um den Einfluss von Störlicht möglichst auszuschalten. Um Fehlalarme durch Licht auszuschalten, welches durch die Raucheintrittsöffnungen eindringt, ist in dem Streulichtrauchmelder der JP-A 52-133 797 ein Verschlussdeckel vorgesehen, welcher die Raucheintrittsöffnungen automatisch verschliesst, sobald das vom Photodetektor abgegebene Signal einen vorbestimmten Schwellenwert überschreitet. Wurde das Signal durch Streulicht verursacht, wird ein Alarm unterdrückt, und die Raucheintrittsöffnungen werden automatisch wieder geöffnet, um den Melder erneut betriebsbereit zu machen.With optical smoke detectors, the measuring chamber is largely closed in order to eliminate the influence of stray light as far as possible. In order to switch off false alarms due to light that penetrates through the smoke entry openings, a scatter cover is provided in the scattered light smoke detector of JP-A 52-133 797, which automatically closes the smoke entry openings as soon as the signal emitted by the photodetector exceeds a predetermined threshold value. If the signal was caused by stray light, an alarm is suppressed and the smoke inlets are automatically opened again to make the detector ready for operation again.

Bei der Konstruktion von lonisations-Rauchmeldern war man im wesentlichen bestrebt, die Messkammer weitgehend gegen die umgebende Atmosphäre offen zu gestalten, um einen ungehinderten Eintritt des Brandaerosols zu erreichen. Beispielsweise ist bei einer Anzahl bekannter Konstruktionen die Messkammer lediglich durch eine gitterartige Haube oder eine Haube mit relativ grossen gitterartigen Oeffnungen von der Aussenatmosphäre getrennt. (vgl. B. Bull.schw. elektrotechn.Verein 43, S.933 ff.)When designing ionization smoke detectors, the main aim was to make the measuring chamber largely open to the surrounding atmosphere in order to achieve unimpeded entry of the fire aerosol. For example, in a number of known constructions, the measuring chamber is separated from the outside atmosphere only by a lattice-like hood or a hood with relatively large lattice-like openings. (cf. B. Bull.schw. Elektrotechn.Verein 43, p.933 ff.)

Bei dem dort beschriebenen Niederspannungsmelder (ca. 220 V) wurde vorgeschlagen zur Herabsetzung des unerwünschten Effektes starker Zugluft eine drehbare Blendenöffnung zum Abdecken der seitlichen Oeffnungen vorzusehen. Bei diesen Rauchmeldern trat dann eine genügend grosse Rauchmenge durch den nur durch ein Gitter geschützten - sonst völlig offenen Boden des Gehäuses in die Rauchmesskammer ein. Die Einstellung der Empfindlichkeit des Rauchmelders zur Anpassung an unterschiedliche Umgebungsbedingungen erfolgte durch Veränderung der Strahlungsintensität der radioaktiven Quelle, beispielsweise durch eine hütchenförmige Blende, durch welche ein Teil der Strahlungsfläche abgedeckt werden konnte.In the low-voltage detector (approx. 220 V) described there, it was proposed to reduce the undesirable effect of strong drafts by providing a rotatable diaphragm opening to cover the side openings. With these smoke detectors, a sufficiently large amount of smoke then entered the smoke measuring chamber through the bottom of the housing, which was only protected by a grille and was otherwise completely open. The sensitivity of the smoke detector was adjusted to adapt to different environmental conditions by changing the radiation intensity of the radioactive source, for example by means of a cone-shaped diaphragm, through which part of the radiation area could be covered.

Alle beschriebenen Konstruktionen besitzen jedoch den Nachteil, dass sie der natürlichen Versfaubung in starkem Masse ausgesetzt sind. Um diesen Nachteil zu beheben, ist vorgeschlagen worden, den Lufteintritt in die lonisationskammer durch geeignete, eine Luftströmung abbremsende oder umlenkende Mittel zu verlangsamen, um das Sedimentieren von Staub vor dem Eintritt in die eigentliche Messkammer zu bewirken. Hierdurch wird jedoch auch der Eintritt von Brandaerosol in die Messkammer erschwert, was zu einer unerwünschten Empfindlichkeitsverringerung der Rauchmelder führt.However, all the constructions described have the disadvantage that they are exposed to a large extent to natural fouling. In order to remedy this disadvantage, it has been proposed to slow down the air entry into the ionization chamber by suitable means which slow down or deflect an air flow in order to cause dust to sediment before entering the actual measuring chamber. However, this also makes it more difficult for fire aerosol to enter the measuring chamber, which leads to an undesirable reduction in the sensitivity of the smoke detectors.

Ein wesentlicher Nachteil der bisher bekannten Rauchmelder besteht darin, dass für jeden Anwendungsbereich speziell angepasste Melder entwickelt werden müssen, um zu erreichen, dass für unterschiedliche Umweltbedingungen jeweils ein optimales Eintreten der Brandaerosole in den Brandmelder gewährleistet ist. Dies führt zu aufwendigen Fabrikationsmethoden, einer unnötigen grossen Lagerhaltung und unnötigem Austausch der Meldereinsätze bei Wechsel der Umweltbedingungen am Einsatzort (Wegfall oder Auftreten von Verstaubungsgefahr, etc.).A major disadvantage of the previously known smoke detectors is that specially adapted detectors have to be developed for each area of application in order to ensure that the fire aerosols enter the fire detector optimally for different environmental conditions. This leads to complex manufacturing methods, an unnecessarily large inventory and unnecessary replacement of the detector inserts when the environmental conditions change at the place of use (elimination or Occurrence of dust, etc.).

Aufgabe der Erfindung ist es, die Nachteile der bisher bekannten Rauchmelder zu beseitigen und insbesondere einen Rauchmelder zu schaffen, der in einfacher Weise an unterschiedliche Umweltbedingungen anpassbar ist. Aufgabe der Erfindung ist es ferner, in konstruktiv einfacher Weise zu ermöglichen, dass die Rauchmelder unter den jeweiligen Umweltbedingungen einen optimalen Eintritt von Brandaerosol in die Rauchmesskammer bei gleichzeitiger optimaler Verhinderung des Eintretens von Staub zu ermöglichen.The object of the invention is to eliminate the disadvantages of the previously known smoke detectors and, in particular, to create a smoke detector which can be easily adapted to different environmental conditions. It is also an object of the invention to enable in a structurally simple manner that the smoke detectors allow optimal entry of fire aerosol into the smoke measurement chamber under the respective environmental conditions while at the same time optimally preventing the occurrence of dust.

Diese Aufgabe wird erfindungsgemäss durch die im kennzeichnenden Teil des Patentanspruchs 1 definierten Merkmale gelöst.This object is achieved according to the invention by the features defined in the characterizing part of patent claim 1.

Es wird darauf hingeweisen, dass aus der CH-A- 551 057 im Rauchmelder bekannt ist, dessen Luftzutrittsöffnungen einen ringförmigen Schlitz in der äusseren Wand des Gehäuses bilden. Dieser Schlitz ist jedoch nicht verstellbar.It is pointed out that it is known from CH-A-551 057 in the smoke detector, the air inlet openings of which form an annular slot in the outer wall of the housing. However, this slot is not adjustable.

Gemäss einer bevorzugten Ausführungsform der Erfindung ist die Verstellvorrichtung so ausgebildet, dass die Oeffnungen nur mittels eines Spezialwerkzeugs verändert werden können.According to a preferred embodiment of the invention, the adjusting device is designed such that the openings can only be changed by means of a special tool.

Gemäss einer weiteren bevorzugten Ausführungsform der Erfindung ist der ringförmige Schlitz durch einen ringförmigen Steg in einen inneren und einen äusseren Teil unterteilt und die Verstellvorrichtung ist so ausgebildet, dass sie den äusseren Teil des ringförmigen Schlitzes verändert. Weitere Ausgestaltungen der Verstellvorrichtungen sind so ausgebildet, dass sie den inneren Teil allein oder gleichzeitig den inneren und äusseren Teil des ringförmigen Schlitzes verändern.According to a further preferred embodiment of the invention, the annular slot is divided into an inner and an outer part by an annular web and the adjusting device is designed such that it changes the outer part of the annular slot. Further refinements of the adjusting devices are designed such that they change the inner part alone or simultaneously the inner and outer part of the annular slot.

Eine weitere bevorzugte Ausführungsform des erfindungsgemässen Rauchmelders besteht darin, dass die Verstellvorrichtung so eingerichtet ist, dass sie stufenweise verändert werden kann und dass eine Markierungsvorrichtung vorgesehen ist, and der die Einstellung der Verstellvorrichtung von aussen abgelesen werden kann.A further preferred embodiment of the smoke detector according to the invention is that the adjustment device is set up in such a way that it can be changed in stages and that a marking device is provided on which the adjustment of the adjustment device can be read from the outside.

Die Erfindung wird anhand von Ausführungsbeispielen beschrieben. Es zeigen

  • Figur 1 einen Querschnitt durch einen Rauchmelder, bei dem der äussere Teil des ringförmigen Schlitzes verändert wird,
  • Figur 2 einen Querschnitt durch einen Brandmelder, bei dem der innere Teil des ringförmigen Schlitzes verändert wird und
  • Figur 3 einen Querschnitt durch einen Brandmelder, bei dem gleichzeitig der äussere und innere Teil des ringförmigen Schlitzes verändert werden kann.
The invention is described using exemplary embodiments. Show it
  • FIG. 1 shows a cross section through a smoke detector in which the outer part of the annular slot is changed,
  • Figure 2 shows a cross section through a fire detector in which the inner part of the annular slot is changed and
  • Figure 3 shows a cross section through a fire detector, in which the outer and inner part of the annular slot can be changed at the same time.

Der in Fig. 1 dargestellte lonisationsfeuermelder besteht aus einem Sockelteil 1 und einem Meldereinsatz 2. Der Sockelteil 1 besitzt seitlich eine Aussparung, welche eine Alarmanzeigelampe 3, z.B. eine Leuchtdiode, enthält.The ionization fire detector shown in Fig. 1 consists of a base part 1 and a detector insert 2. The base part 1 has a recess on the side, which an alarm indicator lamp 3, e.g. contains a light emitting diode.

Der Meldereinsatz 2 weist ein aus einer zylindrischen oder leicht konischen Hülse 4 und einem unteren Deckel 5 bestehendes Gehäuse auf. Zwischen Hülse 4 und Deckel 5 befindet sich ein ringförmiger Schlitz 13 zum Eintritt der Luft in das Gehäuseinnere. An der Deckelinnenseite ist ein zylindrischer Steg 12 vorgesehen, durch den die einströmende Luft gebremst und gestaut wird, bevor sie in das Innere des Gehäuses geleitet wird. Auf dem zylindrischen Steg 12 befindet sich ein Ring 15, der in axialer Richtung so verschoben werden kann, dass der die äussere Eintrittsöffnung bildende ringförmige Schlitz 13 in seiner Breite verändert werden kann.The detector insert 2 has a housing consisting of a cylindrical or slightly conical sleeve 4 and a lower cover 5. Between the sleeve 4 and the cover 5 there is an annular slot 13 for the entry of air into the interior of the housing. A cylindrical web 12 is provided on the inside of the cover, by means of which the inflowing air is braked and blocked before it is conducted into the interior of the housing. On the cylindrical web 12 there is a ring 15 which can be displaced in the axial direction in such a way that the width of the annular slot 13 forming the outer inlet opening can be changed.

Im Gehäuseinnern ist eine Trägerplatte 6 aus Isoliermaterial angebracht, an welcher alle weiteren Bauteile montiert sind. Eine zentrale Bohrung enthält einen Metallstempel 7, welcher eine scheibenförmige Elektrode 8 mit einem radioaktiven Präparat 9 trägt. An der Unterseite der Trägerplatte 6 ist weiter eine als Drahtgitter mit zahlreichen kleinen Oeffnungen ausgebildete Gegenelektrode 11 angebracht, welche die innere Elektrode 8 umgibt und vor einer Berührung schützt. Die Mittelelektrode 8 und die Gegenelektrode 11 definieren die lonisationskammer 10. Oberhalb der Trägerplatte 6 kann eine bekannte elektrische Schaltung zur Auswertung der lonenstromänderung der Kammer 10 angebracht sein, welche eine von der Aussenatmosphäre nahezu abgeschlossene Referenz-lonisationskammer enthalten kann, die in bekannter Weise in Serie mit der lonisationskammer 10 geschaltet ist. Der Deckel 5 des Gehäuses ist vorteilhafterweise von der Hülse 4 abnehmbar ausgebildet, um eine Reinigung zu erleichtern.A carrier plate 6 made of insulating material is attached to the inside of the housing, on which all other components are mounted. A central bore contains a metal stamp 7, which carries a disk-shaped electrode 8 with a radioactive preparation 9. On the underside of the carrier plate 6 there is also a counterelectrode 11 in the form of a wire mesh with numerous small openings, which surrounds the inner electrode 8 and protects it from contact. The center electrode 8 and the counter electrode 11 define the ionization chamber 10. Above the carrier plate 6, a known electrical circuit for evaluating the change in ion current of the chamber 10 can be attached, which can contain a reference ionization chamber which is almost completely sealed off from the outside atmosphere and which is produced in series in a known manner is connected to the ionization chamber 10. The cover 5 of the housing is advantageously designed to be removable from the sleeve 4 in order to facilitate cleaning.

Figur 2 zeigt einen Ausschnitt eines weiteren Ausführungsbeispiels eines Brandmelders mit den gleichen technischen Vorteilen, bei welchem sich auf der Innenwand des Gehäuses 4 ein Vorsprung 16 befindet, der für eine weitere Umlenkung der eintretenden Luft sorgt. Zur Anpassung des Rauchmelders an verschiedene Umweltbedingungen befindet sich an der Innenseite des Stegs 12 ein verschiebbarer Zylinder 17, der entweder durch eine gewisse Vorspannung kraftschlüssig an der Innenwand des zylinderförmigen Steges 12 haftet, oder der durch nichtdargestellte Federn an mehreren Stellen des Umfangs an der Aussenseite des Steges 12 befestigt ist. Durch axiale Verschiebung des Zylinders 17 wird die innere Eintrittsöffnung 20 des Rauchmelders verändert. Für eine stufenweise Veränderung des Eintrittquerschnitts können auf der Innenseite des Steges 12 Nuten angebracht sein, in die entsprechende Vorsprünge des Zylinders 17 eingreifen oder es können entsprechende Nuten auf der Aussenseite des Steges 12 angebracht sein, in welche entsprechende Vorsprünge der Befestigungsfedern eingreifen.Figure 2 shows a section of a further embodiment of a fire detector with the same technical advantages, in which there is a projection 16 on the inner wall of the housing 4, which ensures a further deflection of the incoming air. In order to adapt the smoke detector to different environmental conditions, a displaceable cylinder 17 is located on the inside of the web 12, which either adheres to the inner wall of the cylindrical web 12 by a certain preload, or which springs (not shown) at several points on the outside of the circumference Web 12 is attached. The inner inlet opening 20 of the smoke detector is changed by axially displacing the cylinder 17. For a gradual change in the inlet cross section, 12 grooves can be provided on the inside of the web, engage in the corresponding projections of the cylinder 17, or corresponding grooves can be provided on the outside of the web 12, in which corresponding projections of the fastening springs engage.

Figur 3 zeigt den Ausschnitt des Querschnitts eines weiteren Ausführungsbeispiels eines Brandmelders mit den gleichen technischen Vorteilen, bei welchem auf der Innenseite der Hülse 4 ein Vorsprung 16 angebracht ist, der eine weitere Umlenkung der eintretenden Luft bewirkt. Zur Anpassung des Rauchmelders an verschiedene Umweltbedingungen befindet sich an der Aussenseite des Steges 12 ein mit einem Flansch 19 versehender Zylinderring 18, der axial auf dem Steg 12 verschiebbar angeordnet ist. Zur stufenweisen Verstellung des Zylinderrings 18 sind auf dem Steg 12 Rillen angebracht, in welche entsprechende Vorsprünge des Zylinderrings 18 eingreifen können. Bei einer axialen Verschiebung des Zylinderrings 18 werden gleichzeitig die äussere Eintrittsöffnung 13 durch den Flansch 19 und die innere Eintrittsöffnung 20 durch den oberen Rand des Zylinderrings 18 verändert.Figure 3 shows a section of the cross section of a further embodiment of a fire alarm with the same technical advantages, in which on the inside of the sleeve 4, a projection 16 is attached, the one causes further deflection of the incoming air. In order to adapt the smoke detector to different environmental conditions, there is a cylinder ring 18 with a flange 19 on the outside of the web 12, which is axially displaceable on the web 12. For the gradual adjustment of the cylinder ring 18 12 grooves are provided on the web, in which corresponding projections of the cylinder ring 18 can engage. In the event of an axial displacement of the cylinder ring 18, the outer inlet opening 13 is changed simultaneously by the flange 19 and the inner inlet opening 20 by the upper edge of the cylinder ring 18.

Die in der vorstehenden Figurenbeschreibung an Hand von Ionisationsrauchmeldern beschriebenen Ausführungsformen, können in analoger Weise bei optischen Rauchmeldern angewendet werden. Ausser den an Hand der Figuren beschriebenen Ausführungsformen können auch Brandmelder mit einem der Luftumlenkung dienenden äusseren und inneren Teil, beispielsweise der Brandmelder gemäss CH-PS 475 614, so ausgebildet werden, dass entweder die Oeffnungen des äusseren oder inneren Teils der Umhüllung durch eine mechanische Verstellvorrichtung verändert werden können.The embodiments described in the description of the figures above using ionization smoke detectors can be applied in an analogous manner to optical smoke detectors. In addition to the embodiments described with reference to the figures, fire detectors with an outer and inner part serving for air deflection, for example the fire detector according to CH-PS 475 614, can also be designed in such a way that either the openings of the outer or inner part of the casing are made by a mechanical adjusting device can be changed.

Claims (5)

1. Smoke detector containing at least one smoke measuring chamber (10), a housing (4, 5) surrounding said smoke measuring chamber (10). said housing being provided with openings (13, 20) for the entry of ambient air into the smoke measuring chamber (10), and a manually adjustable means (15,17,18,19) for changing the air entry openings (13, 20), characterized in that said air entry openings (13, 20) are constructed as an annular slit in the external wall of the housing (4) and that said adjustable means (15, 17, 18, 19) consists of an axial shiftable ring (15, 17, 18, 19), which serves to change the width of the annular slit (13, 20) for the air entry.
2. Smoke detector according to patent claim 1, characterized in that the annular slit (13, 20) is divided by an annular web (12) into an inner (20) and an outer part (13) and that the adjustable meams (15) is structured to change the enter part of the annular slit (13).
3. Smoke detector accordimg to anyone of the patent claims 1 and 2, characterized in that the adjustable means (15) contains structure for the stepwise change of the entry openings (13, 20).
4. Smoke detector according to anyone of the patent claims 1 to 3, characterized in that marking means are provided for enabling discerning of the position of the adjustable means (15,17,, 18, 19).
5. Smoke detector according to anyone of the patent claims 1 to 4, characterized in that the adjustable means (15, 17, 1819) is structured such that it can be only adjusted with the aid of a special tool.
EP81103313A 1980-05-09 1981-05-02 Smoke detector Expired EP0040342B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT81103313T ATE25438T1 (en) 1980-05-09 1981-05-02 SMOKE DETECTOR.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH3641/80A CH648943A5 (en) 1980-05-09 1980-05-09 SMOKE DETECTOR.
CH3641/80 1980-05-09

Publications (2)

Publication Number Publication Date
EP0040342A1 EP0040342A1 (en) 1981-11-25
EP0040342B1 true EP0040342B1 (en) 1987-02-04

Family

ID=4260347

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81103313A Expired EP0040342B1 (en) 1980-05-09 1981-05-02 Smoke detector

Country Status (10)

Country Link
US (2) US4384488A (en)
EP (1) EP0040342B1 (en)
JP (1) JPS6033514Y2 (en)
AT (1) ATE25438T1 (en)
AU (1) AU541729B2 (en)
CA (1) CA1150381A (en)
CH (1) CH648943A5 (en)
DE (1) DE3175913D1 (en)
DK (1) DK113281A (en)
NO (1) NO153024C (en)

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CN110322658B (en) * 2019-08-02 2024-01-30 四川赛科安全技术有限公司 Top type reverse smoke inlet labyrinth structure and implementation method thereof
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Also Published As

Publication number Publication date
NO811586L (en) 1981-11-10
NO153024C (en) 1986-01-02
AU541729B2 (en) 1985-01-17
NO153024B (en) 1985-09-23
DE3175913D1 (en) 1987-03-12
ATE25438T1 (en) 1987-02-15
JPS6033514Y2 (en) 1985-10-05
US4384488A (en) 1983-05-24
DK113281A (en) 1981-11-10
CA1150381A (en) 1983-07-19
AU7011381A (en) 1981-11-12
CH648943A5 (en) 1985-04-15
EP0040342A1 (en) 1981-11-25
US4475390A (en) 1984-10-09
JPS5710097U (en) 1982-01-19

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