(19)
(11) EP 1 528 576 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
01.02.2006 Bulletin 2006/05

(43) Date of publication A2:
04.05.2005 Bulletin 2005/18

(21) Application number: 04025657.0

(22) Date of filing: 28.10.2004
(51) International Patent Classification (IPC): 
H01B 17/18(2006.01)
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR
Designated Extension States:
AL HR LT LV MK

(30) Priority: 28.10.2003 JP 2003367240

(71) Applicant: Hitachi, Ltd.
Tokyo (JP)

(72) Inventors:
  • Morita, Kiyoshi
    Chiyoda-ku Tokyo 100-8220 (JP)
  • Sugimura, Kazuyuki
    Chiyoda-ku Tokyo 100-8220 (JP)
  • Chono, Takahiro
    Chiyoda-ku Tokyo 100-8220 (JP)
  • Hattori, Morishige
    Chiyoda-ku Tokyo 100-8220 (JP)
  • Hashimoto, Katsufumi
    Shibuya-ku Tokyo 151-8578 (JP)
  • Kurita, Takeshi
    Shibuya-ku Tokyo 151-8578 (JP)

(74) Representative: Beetz & Partner 
Steinsdorfstrasse 10
80538 München
80538 München (DE)

   


(54) Electrical insulator


(57) An electrical insulator (1) includes a shed (31) having a diameter larger than the shed diameter of the electrical insulator (1) in an upper portion of the electrical insulator (1), and the shed (31) has an elliptical or oval cross section. Accordingly, the airflow in the vertical direction of the electrical insulator (1) is reduced, and therefore the noise caused by pressure fluctuation on a shed of the electrical insulator (1) due to vortices generated at positions downstream of a structural component, such as a collector shoe, placed on top of the electrical insulator (1) is reduced.







Search report