Classifications

• • G—PHYSICS
  • G08—SIGNALLING
  • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
  • G08B17/00—Fire alarms; Alarms responsive to explosion
• • 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

• This invention relates to an improved detector and in particular to a detector which may be a thermal, smoke or other detector adapted to be located in a building, normally on a ceiling thereof•
• the detectors may simply operate to close a circuit, which provides an alarm or other function at a remote position, or they may be intelligent in that they contain a micro processor and are continually interrogated from a remote position so that their status can be ascertained.
• This second form is becoming more common as it ensures that the detector is in fact operative whereas in the passive forms of detector, reliance has to be placed on the fact that the detector will operate when an alarm condition occurs.
• detectors must have an indicator which shows when the detector is operative and such indicators can conventionally be LED's but they could also be incandescent
• a problem that has been found with the current indicator devices is that they are normally located either on the body of the detector itself, or on the detector-base and their illumination can be very directionally selective so that it can be very difficult to see whether they are in fact illuminated or not.
• the principal object of the present invention is to provide a detector in which this difficulty is minimised.
• the detector of the invention has a base having about part of its periphery a surface which is transparent or translucent and having located internally at least one source of illumination which can effect the illumination of at least a part of the surface.
• the surface can effectively be at an angle which is directed outwardly from the base and thus, when the base is positioned on the ceiling or the like, is directed downwardly and outwardly.
• Figure 1 is a perspective view of one form of detector showing how it would be normally mounted
• Figure 2 is a plan view of one form of base which might be used with the invention.
• Figure 3 is a side elevation of the base of Figure 2.
• Figure 4 is a schematic view of one possible form of circuit board adapted to be located in the base.
• the detector 10 is shown to be generally circular in plan, although it will be understood that the aspects of the invention can be applied to detectors of different shapes.
• the detector has a base 11 and a cover 12 and the base itself may be made of two components 13, 14 as will be described hereafter.
• the components are preferably made of moulded synthetic plastics materials, for cheapness of manufacture of large quantities of components, and the component 14 of the base is made of a plastics material which is transparent or translucent.
• the component 13, which may be an annular ring which fits over the component 14 and abuts a shoulder 16 thereon and the cover 12 are solid and light impervious.
• This bevel 15 is so arranged that if the base is illuminated from the inside then the bevel will also become illuminated.
• the cover 12 is designed to permit operation of the type of detector to be used and again is of an opaque material.
• circuit board 30 comprising the necessary circuitry for operation of the detector.
• the form of the circuit board is constrained by the shape and size of the detector and the circuitry will, of course, depend on the type of the detector. It is preferred that the base and cover are readily attached one to the other and that any necessary electrical connections which need to be made between components on the different parts are made automatically as they are connected. For example, if the transducer is mounted on the cover, then its connection to the circuit can be by way of complimentary connectors on the base 11 and the cover 10.
• LEDs light emitting diodes
• circuit board 30 is in the form of an arc of a circle adapted to be located adjacent the periphery of the detector and is connected to the base 11.
• Two of the LEDs, 31, 32 are adjacent the edge of the board and are directed outwardly so as to terminate inwardly of the base adjacent the position of the bevel 15 and the third 33 can be generally inwardly directed.
• a light pipe 34 which can simply be a rod of transparent plastics material which has one end adjacent the LED 33 and the other end adjacent the inside of the base substantially bisecting the obtuse included angle between the other two LEDs*, 31, 32. That is the effective outputs from the LEDs' are located more or less equiangularly about the periphery of the base.
• the actual location may not be equiangular as the spacing of the first two LEDs' are dependant upon the size of the circuit board and these may, for example, be at approximately 90 degrees subtended angle to the centre of the base from each other rather than 120 degrees, which would be required for the spacing to be equiangular.
• a material such as a fluorescent paint or other light enhancing material. If, for example a fluorescent paint is used this will absorb light from the illumination source and retransmit it in a narrow frequency band which can readily be seen. Also whilst we have described the invention in relation to a circular detector having three LEDs it will be understood that the same arrangement can be provided for different shaped detectors and for different arrangements of light sources.
• detectors of different shapes for example a square or rectangular detector which means whereby each of the sides of the detector could be illuminated.

Landscapes

• Business, Economics & Management (AREA)
• Emergency Management (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Fire Alarms (AREA)
• Fire-Detection Mechanisms (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=3775214

Family Applications (1)

Country Status (3)

Cited By (2)

Families Citing this family (5)

Citations (6)

Family Cites Families (2)

• 1992
  • 1992-02-07 EP EP92903921A patent/EP0570431A4/en not_active Withdrawn
  • 1992-02-07 WO PCT/AU1992/000042 patent/WO1992014223A1/en not_active Application Discontinuation
  • 1992-02-07 JP JP4503871A patent/JPH06505106A/ja active Pending

Patent Citations (6)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events