(19)
(11) EP 1 975 896 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
18.03.2009 Bulletin 2009/12

(43) Date of publication A2:
01.10.2008 Bulletin 2008/40

(21) Application number: 08251196.5

(22) Date of filing: 28.03.2008
(51) International Patent Classification (IPC): 
G08B 17/10(2006.01)
G08B 17/107(2006.01)
 G08B 17/113(2006.01)
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR
Designated Extension States:
AL BA MK RS

(30) Priority: 30.03.2007 JP 2007091276

(71) Applicant: NOHMI BOSAI LTD.
Chiyoda-ku Tokyo (JP)

(72) Inventor:
  • Yokota, Hiroyuki c/oNohmi Bosai Ltd.
    Chiyoda-ku, Tokyo (JP)

(74) Representative: Mounteney, Simon James 
Marks & Clerk 90 Long Acre
London WC2E 9RA
London WC2E 9RA (GB)

   


(54) Smoke detector and sampling air supplying method for smoke detector


(57) In order to enable supply of a sampling air to a smoke detection portion at a stable flow velocity, the present invention provides a smoke detector including: a black box (21) including a smoke detection portion (25) having an inflow port and an outflow port; a sampling pipe (30) laid in a monitor space; a gas flow pipe (P) connected to the sampling pipe and which houses a fan (3) therein; a flow path branching portion (33) provided to the gas flow pipe on a secondary side of the fan and connected to the inflow port of the smoke detection portion; and a flow path merging portion (32) which is provided to the gas flow pipe on the secondary side of the fan and connected to the outflow port of the smoke detection portion, and at which a pressure of a fluid flowing through the gas flow pipe is lower than a fluid flowing through the gas flow pipe at the flow path branching portion. Such pressure difference ensures that a constant flow rate is maintained in the smoke detection portion, thereby enabling a reliable smoke detection.







Search report