(19)
(11) EP 0 978 858 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
25.10.2000 Bulletin 2000/43

(43) Date of publication A2:
09.02.2000 Bulletin 2000/06

(21) Application number: 99305863.5

(22) Date of filing: 23.07.1999
(51) International Patent Classification (IPC)7: H01H 71/02, H01H 73/04, H01H 71/24
(84) Designated Contracting States:
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
Designated Extension States:
AL LT LV MK RO SI

(30) Priority: 04.08.1998 JP 22009498

(71) Applicant: HITACHI, LTD.
Chiyoda-ku, Tokyo (JP)

(72) Inventors:
  • Yamada, Yukihide
    Niigata-shi, Niigata-ken (JP)
  • Sekiguchi, Toshihiro
    Kitakanbara-gun, Niigata-ken (JP)
  • Aihara, Kazuya
    Kitakanbara-gun, Niigata-ken (JP)
  • Sato, Eietsu
    Kitakanbara-gun, Niigata-ken (JP)

(74) Representative: Calderbank, Thomas Roger et al
MEWBURN ELLIS York House 23 Kingsway
London WC2B 6HP
London WC2B 6HP (GB)

   


(54) Circuit breaker


(57) It is an object of the present invention to provide a circuit breaker excellent in safety by electrically insulating the trip unit from the main circuit, and capable of performing a proper wiping of the movable contact carrier, resulting in reduction of electrical resistance at the contacts. Further, a circuit breaker excellent in workability in assembling processes is also provided.
In the circuit breaker of the present invention, a housing means (22) contains a main circuit (100) including a power supply side stationary contact carrier (1) with a stationary contact (2), a movable contact carrier (4) with a power supply side movable contact (3) and a load side movable contact (5), and a load side stationary contact carrier (7) with a load side stationary contact (6). The housing means is made of insulating material and disposed in the casing (40) also made of insulating material. The circuit breaker includes a make-and-break mechanism (30), a tripping mechanism (50). The tripping mechanism (50) is unitedly connected to the load side stationary contact carrier (7) and to the load side terminal (7c) therebetween. The tripping means (50) includes a converting mechanism (51) for converting electromagnetic force to mechanical force for tripping, which is supported on the housing means (22) and is electrically insulated from the main circuit (100). The make-and-break mechanism (30) is mounted on the housing means (22) and is electrically insulated from the main circuit (100).






Search report