公开(公告)号：WO1991000609A1

公开(公告)日：1991-01-10

申请号：PCT/JP1990000835

申请日：1990-06-27

Applicant: HITACHI, LTD.

Inventor： HITACHI, LTD. ,  SHIMANO, Terumi ,  SAKAI, Kuniyoshi ,  SAITO, Tomoyoshi ,  SHIODA, Kinichi ,  SUZUKI, Hiroshi ,  TERAOKA, Wataru ,  KATO, Kazuhiko

IPC: H01H71/43

CPC classification number: H01H77/108

Abstract: A circuit breaker equipped with a mechanism for current limiting by the use of electromagnetic repulsion, aiming at solving a technical problem of improving current-limiting performance by increasing the contact-opening speed of a contact plate of a current-limiting type circuit breaker and realizing the device in a compact size. The current-limiting contact plate is rotatably supported at its central portion, with one end thereof facing a movable contact plate, and with the other end facing a fixed conductor and electrically connected thereto. An electromagnetic repulsive force between the movable contact plate and the current-limiting contact plate and an electromagnetic repulsive force between the fixed conductor and the current-limiting contact plate are used as a couple of forces. It is therefore possible to increase the contact-opening speed and to decrease the distance between the current-limiting contact plate and the fixed conductor. The invention provides a circuit breaker which is small in size and is excellent in breaking performance.