Scattered Light Smoke Detector

Abstract

The smoke detector contains an optical measuring chamber, having a sensor arrangement with at least one light source and one light receiver, and a labyrinth system with screens arranged on the periphery of the measuring chamber. The light source and the light receiver are each arranged in a housing. The housings have an elongated shape and a small window opening The at least one light source and light receiver are arranged in the rear part of their housings, so that between the window openings of the housings and the light-penetrated optical surfaces of the at least one light source and/or the lens of the light receiver a relatively large gap is formed. This gap is preferably greater than the diameter of the above-mentioned optical surfaces, or of the lens. In the measuring chamber between the light exit and entry side of the housings and the screens opposite them, a compact, open scattering space is formed.

1 . A scattered light smoke detector with an optical measuring chamber, comprising:
 a carrier disc forming an ceiling of a measuring chamber and having at least two housings extending downwardly therefrom, said housings having an elongated shape, a rear part, and a small window opening opposite said rear part;   a sensor arrangement with a light source disposed in said rear part of a first one of said housings and a light receiver disposed in said rear part of a second one of said housings, such that a relatively large gap is formed between said window opening of said housing and a light-penetrated optical surface of at least one of said light source and said light receiver; and   a lid component configured to be plugged onto said carrier disc from below, said lid component having a floor and side walls defining said measuring chamber together with said carrier disc, a labyrinth system with screens arranged on a periphery of said measuring chamber.   
   
   
       2 . The smoke detector of  claim 1 , wherein the gap is greater than a diameter of the optical surface. 
   
   
       3 . The smoke detector of  claim 1 , wherein the window opening of the housing is enclosed by a one-part frame. 
   
   
       4 . The smoke detector of  claim 1 , wherein the housings, apart from the window opening, are downwardly open and said floor of said lid component has lids for said housings. 
   
   
       5 . The smoke detector of  claim 1 , wherein in the measuring chamber between a light exit and an entry side of the housing and screens opposite them, a compact, open scattering space is formed. 
   
   
       6 . The smoke detector of  claim 5 , wherein the housing has grooves formed therein for fixing polarization filters. 
   
   
       7 . The smoke detector of  claim 6 , wherein the surfaces, which face each other, of the carrier disc and the floor of the component which forms the labyrinth system are formed with corrugations. 
   
   
       8 . The smoke detector of  claim 7 , wherein the screens and the corrugated surfaces of the carrier disc and of the floor of the component have a glossy surface. 
   
   
       9 . The smoke detector of  claim 5 , wherein the screens are arranged on the periphery of the measuring chamber and are substantially L-shaped, the shorter leg pointing into the measuring chamber, and the gap between adjacent screens is a multiple of their thickness. 
   
   
       10 . The smoke detector of  1 , wherein on the carrier disc, a multiple plug for the electrical connection of the detector to a plug connector which is provided in a detector base is arranged, and that the electrical connection is made by a tangential movement of the multiple plug or plug connector. 
   
   
       11 . The smoke detector of  claim 10 , wherein the multiple plug is integrated on the top side of the carrier disc, in so-called insert technology. 
   
   
       12 . The smoke detector of  claim 6 , wherein the screens are arranged on the periphery of the measuring chamber and are substantially L-shaped, the shorter leg pointing into the measuring chamber, and the gap between adjacent screens is a multiple of their thickness. 
   
   
       13 . The smoke detector of  claim 7 , wherein the screens are arranged on the periphery of the measuring chamber and are substantially L-shaped, the shorter leg pointing into the measuring chamber, and the gap between adjacent screens is a multiple of their thickness. 
   
   
       14 . The smoke detector of  claim 8 , wherein the screens are arranged on the periphery of the measuring chamber and are substantially L-shaped, the shorter leg pointing into the measuring chamber, and the gap between adjacent screens is a multiple of their thickness. 
   
   
       15 . The smoke detector of  claim 5 , wherein on the carrier disc, a multiple plug for the electrical connection of the detector to a plug connector which is provided in a detector base is arranged, and that the electrical connection is made by a tangential movement of the multiple plug or plug connector. 
   
   
       16 . The smoke detector of  claim 6 , wherein on the carrier disc, a multiple plug for the electrical connection of the detector to a plug connector which is provided in a detector base is arranged, and that the electrical connection is made by a tangential movement of the multiple plug or plug connector. 
   
   
       17 . The smoke detector of  claim 8 , wherein on the carrier disc, a multiple plug for the electrical connection of the detector to a plug connector which is provided in a detector base is arranged, and that the electrical connection is made by a tangential movement of the multiple plug or plug connector. 
   
   
       18 . The smoke detector of  claim 9 , wherein on the carrier disc, a multiple plug for the electrical connection of the detector to a plug connector which is provided in a detector base is arranged, and that the electrical connection is made by a tangential movement of the multiple plug or plug connector. 
   
   
       19 . The smoke detector of  claim 18 , wherein the multiple plug is integrated on the top side of the carrier disc, in insert technology.