(19)
(11) EP 0 507 330 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
19.11.1992 Bulletin 1992/47

(43) Date of publication A2:
07.10.1992 Bulletin 1992/41

(21) Application number: 92105798.0

(22) Date of filing: 03.04.1992
(51) International Patent Classification (IPC)5: H01T 1/00, H01T 1/22, H01T 13/04
(84) Designated Contracting States:
DE FR GB IT

(30) Priority: 05.04.1991 JP 72000/91
19.03.1992 JP 63576/92
23.03.1992 JP 15084/92 U

(71) Applicant: YAZAKI CORPORATION
Minato-ku Tokyo 108 (JP)

(72) Inventors:
  • Wakabayashi, Seiichi, c/o Yazaki Parts Co., Ltd.
    Gotenba-shi, Shizuoka 412 (JP)
  • Hirano, Takashi, c/o Yazaki Parts Co., Ltd.
    Haibara-gun, Shizuoka 421-04 (JP)
  • Sone, Yukio, c/o Yazaki Parts Co., Ltd.
    Haibara-gun, Shizuoka 421-04 (JP)
  • Ashizawa, Toshikazu, c/o Yazaki Parts Co., Ltd.
    Gotenba-shi, Shizuoka 412 (JP)

(74) Representative: Grünecker, Kinkeldey, Stockmair & Schwanhäusser Anwaltssozietät 
Maximilianstrasse 58
80538 München
80538 München (DE)


(56) References cited: : 
   
       


    (54) A gas-filled discharge tube


    (57) The object of the present invention is to provide a gas-filled discharge tube which is capable of making the discharge tube itself smaller to minimize a plug cap that incorporates the discharge tube therein, thereby to realize a minimization of the size of the whole ignition system having a series gap.
    In order to achieve the above object, the gas-filled discharge tube according to the present invention is constructed such that it comprises a tubular body formed of an electrically insulating material and having a notch portion at least one of the opposite open ends thereof, and a notch or projecting portion at the other open end thereof; a pair of electrode bases, at least one of which is formed of an electrically conducting thin metal sheet, airtightly adhered to the respective open ends; and a pair of discharge electrodes having flange portions to be engageably fixed with the notch and/or projecting portions and sandwiched between the tubular body and the respective electrode bases, and with this construction, the electrode base is first formed with a gas filling bore by a laser beam for filling an inert gas, which bore being welded also by the laser beam after the inert gas is filled in the tubular body so as to enclose the gas therein.






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