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US-12626573-B2 - Housing for a scattered light detection unit of a smoke detection device

US12626573B2US 12626573 B2US12626573 B2US 12626573B2US-12626573-B2

Abstract

A housing for a scattered light detection unit of a smoke detection device, the housing comprises a base ( 2 ) fastened to a mounting plate ( 1 ), the base is provided with guiding channels ( 8 ) for mounting and directing optical elements, and limiting barriers ( 9 ) are attached to the channels ( 8 ), the barriers are arranged on an inner end surface ( 10 ) of the base ( 2 ) and surrounded by an opaque wall ( 7 ) that is concentric to a lateral outer wall ( 6 ), a casing ( 3 ) mounted on the base ( 2 ), the casing has a lateral portion ( 13 ) that encompasses the base ( 2 ) and the mounting plate ( 1 ) and a disc portion ( 15 ) that is parallel to the base ( 2 ), the disc portion is provided with an opening ( 16 ) having an edge that is directed towards the base ( 2 ) and coaxial to the opaque wall ( 7 ), and a cover element ( 7 ) that is fastened on the casing ( 3 ).

Inventors

  • Mykhailo Hlushchenko
  • Volodymyr Maiorov

Assignees

  • AJAX SYSTEMS CYPRUS HOLDINGS LTD

Dates

Publication Date
20260512
Application Date
20230905
Priority Date
20221219

Claims (17)

  1. 1 . A housing for a scattered light detection unit of a smoke detection device, the housing comprising a base ( 2 ) fastened to a mounting plate ( 1 ), the base comprising guiding channels ( 8 ) for mounting and directing optical elements; limiting barriers ( 9 ) attached to the channels ( 8 ), the limiting barriers arranged on an inner end surface ( 10 ) of the base ( 2 ) and surrounded by an opaque wall ( 7 ) that is concentric to a lateral outer wall ( 6 ); a casing ( 3 ) mounted on the base ( 2 ), the casing having a lateral portion ( 13 ) that encompasses the base ( 2 ), the mounting plate ( 1 ), and a disc portion ( 15 ) that is parallel to the base ( 2 ), the disc portion comprising an opening ( 16 ) having an edge that is directed towards the base ( 2 ) and that is coaxial to the opaque wall ( 7 ); and a cover element ( 4 ) fastened on the casing ( 3 ), wherein the casing ( 3 ) is fixable on the base ( 2 ), thereby fitting the edge of the opening ( 16 ) to an edge of the opaque wall ( 7 ), wherein the limiting barriers ( 9 ) are vertically arranged relative to the inner end surface ( 10 ) and opposite to each other, while forming a gap between them, wherein a height of the barriers ( 9 ) is not more than a height of the opaque wall ( 7 ), wherein the edge of the opening ( 16 ) of the casing ( 3 ) is directed by an annular protrusion ( 17 ) provided on an outer surface of the disc portion ( 15 ), the annular protrusion being connected to the edge of the opening ( 16 ) by a curved tilted area ( 18 ), wherein the cover element ( 4 ) comprises a central portion ( 19 ) that is closed at one end and faced towards the casing ( 3 ) with an open end, a peripheral portion ( 20 ) having series of concentrically arranged longitudinal slit-like openings ( 21 ), and a lateral portion ( 22 ) that is fixable on the lateral portion ( 13 ) of the casing ( 3 ), wherein an inner end surface of the central portion ( 19 ) is curved, while forming a smooth transition to a cone-like protrusion ( 28 ) from its edge to its center, and a height of the cone-like protrusion ( 28 ) is not more than a length of the central portion ( 19 ), wherein a diameter of the open end of the central portion ( 19 ) is the same as a diameter of the opening ( 16 ), wherein the peripheral portion ( 20 ) of the cover element ( 4 ) is divided into sectors by equidistant radial partitions ( 26 ), and wherein the lateral portion ( 22 ) of the cover element ( 4 ) is fixable on the lateral portion ( 13 ) of the casing ( 3 ), with an annular slit ( 24 ) formed between the open end of the central portion ( 19 ) and a curved tilted area ( 18 ) of the disc portion ( 15 ) of the casing ( 3 ), and lower portions of the radial partitions ( 26 ) of the peripheral portion ( 20 ) fit to the disc portion ( 15 ) of the casing ( 3 ).
  2. 2 . The housing for the detection unit according to claim 1 , wherein the disc surface ( 15 ), the outer surface of the cover element ( 4 ), the opaque wall ( 7 ), the inner end surface ( 10 ) and the barrier elements ( 9 ) are polished, while an inner surface of the central portion ( 19 ), the curved tilted area ( 18 ) and the edge of the opening ( 16 ) have a SPI-SPE-D1 grade texturing.
  3. 3 . The housing for the detection unit according to claim 1 , wherein coaxial scattering elements formed as vertical ribs ( 29 ) are provided on a surface of the edge of the opening ( 16 ) and on the inner surface of the central portion ( 19 ).
  4. 4 . The housing for the detection unit according to claim 1 , wherein a number of the radial partitions ( 26 ) is from 6 to 8.
  5. 5 . The housing for the detection unit according to claim 1 , wherein a cross-sectional area of the openings ( 21 ) is 30-40% of a general surface area of the peripheral portion ( 20 ).
  6. 6 . The housing for the detection unit according to claim 2 , wherein coaxial scattering elements formed as vertical ribs ( 29 ) are provided on a surface of the edge of the opening ( 16 ) and on the inner surface of the central portion ( 19 ).
  7. 7 . The housing for the detection unit according to claim 2 , wherein a number of the radial partitions ( 26 ) is from 6 to 8.
  8. 8 . The housing for the detection unit according to claim 3 , wherein a number of the radial partitions ( 26 ) is from 6 to 8.
  9. 9 . The housing for the detection unit according to claim 6 , wherein a number of the radial partitions ( 26 ) is from 6 to 8.
  10. 10 . The housing for the detection unit according to claim 2 , wherein a cross-sectional area of the openings ( 21 ) is 30-40% of a general surface area of the peripheral portion ( 20 ).
  11. 11 . The housing for the detection unit according to claim 3 , wherein a cross-sectional area of the openings ( 21 ) is 30-40% of a general surface area of the peripheral portion ( 20 ).
  12. 12 . The housing for the detection unit according to claim 6 , wherein a cross-sectional area of the openings ( 21 ) is 30-40% of a general surface area of the peripheral portion ( 20 ).
  13. 13 . The housing for the detection unit according to claim 4 , wherein a cross-sectional area of the openings ( 21 ) is 30-40% of a general surface area of the peripheral portion ( 20 ).
  14. 14 . The housing for the detection unit according to claim 7 , wherein a cross-sectional area of the openings ( 21 ) is 30-40% of a general surface area of the peripheral portion ( 20 ).
  15. 15 . The housing for the detection unit according to claim 8 , wherein a cross-sectional area of the openings ( 21 ) is 30-40% of a general surface area of the peripheral portion ( 20 ).
  16. 16 . The housing for the detection unit according to claim 9 , wherein a cross-sectional area of the openings ( 21 ) is 30-40% of a general surface area of the peripheral portion ( 20 ).
  17. 17 . The housing for the detection unit according to claim 1 , wherein the height of the cone-like protrusion ( 28 ) is not more than a half length of the central portion ( 19 ).

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to Ukrainian Application No. a 2022 04859, filed Dec. 19, 2022, which is hereby incorporated by reference in its entirety. FIELD OF THE INVENTION The invention relates to structural features of a housing for a smoke optical detection device that detects smoke particles within an aerial space, a so-called smoke chamber, which is formed by elements of the housing, by detecting their reflection in a light by means of a light-sensitive element, the reflection is generated by a light-emitting element in a field of intersection of emission beams with a vision field of a light receiver. PRIOR ART Today, smoke detection devices which comprise photoelectric smoke sensors which operate according to a light scattering principle are the most common and serve as an effective preventive tool to inhibit a fire. Their important operation parameters, as well as in any other smoke sensor, include a possibility to provide a maximum high level of smoke detection and a low level of false actuations, thereby enabling to increase the operation efficiency significantly. These parameters are achieved by selecting physical characteristics of sensors, mathematical characteristics of their adjustment, as well as, what is essential, by modeling features of elements which together form a structure of the sensor's detection unit. Main requirements for structures of housings for detection units include formation of a smoke chamber, provision of an opaqueness for this chamber from outside and avoidance of a contact between beams of a light emitter and a vision field of a light receiver. Also, an important task is to provide a cleanliness of an interior of the housing by avoiding penetration of external contaminants such as dust, ash residues, insects etc., which could otherwise distort the detection results or lead to a general failure of the device. A prior art teaches a plurality of solutions for modeling housings for a detection unit of photoelectric sensors of a smoke detection device, in particular, the one disclosed in the application US2022268681A1 dated Aug. 25, 2022, which discloses a housing for a detection unit, the housing comprises a cylindrical outer surface having openings through which smoke particles enter the housing and a radially symmetric light-guiding structure having guiding members which form a smoke chamber and are so designed that adjacent guiding members each form a guiding channel through which an emission emitted by a light source and not scattered by the smoke particles is guided to outside towards the smoke openings by multiple reflection. Therewith, the housing comprises a base with a light source and a light receiver mounted thereon in holders, and the light source and the light receiver are directed such that a path of the emission beam emitted by the light source and a vision field of the light receiver, where the scattered emission is detected, form an intersection area that is located outside a plane in which the light source and the light detector are arranged. An additional barrier that avoids the light from entering the vision field of the light receiver is a light reflecting cone that is provided on an inner end surface of a cover element of the housing. A drawback of said housing is that said guiding elements perform both light protecting and filtering functions, while in order to perform these functions effectively, the guiding elements should be profiled with such a mathematical precision that is not achievable under mass production conditions, thus, an achievement of both maximum filtration and opaqueness is doubtful. Furthermore, according to the structure, a main location for detecting the scattered light is located closer to a bottom of the chamber which is caused by the fact that the holders of the light sources and the light receiver are arranged almost right next to each other, which, in turn, may cause false actuations, since areas which contribute to dust sedimentation are formed both at the bottom of the chamber and on the holders, thereby increasing a probability of false actuations. Also, the prior art teaches a patent KR101963111B1 dated Jul. 31, 2019 which discloses a photoelectric smoke detection device comprising a scattered light sensor that is provided in a housing that consists of a base fastened to a mounting plate that is attached to a control board for controlling a power unit, and the base is provided with holders for mounting and directing optical elements which are arranged in a space that is limited by an opaque wall that is concentric to a lateral outer wall. A casing is mounted on the base, the casing has a lateral portion encompassing the base and a disc portion that is parallel to the base, the disc portion is provided with an opening having an edge that is directed towards the base and is coaxial with the opaque wall. The casing is closed from a top with a cover element formed as an opaque film