IMPROVEMENTS IN OR RELATING TO MOLDED CASE CIRCUIT BREAKER WITH AN APERTURED MOLDED CROSS BAR FOR SUPPORTING A MOVABLE ELECTRICAL CONTACT ARM

摘要

pThe invention relates to an electric circuit breaker having improved operating means with current-limiting capability. The operating means include an insulating cross-bar (84) pivotally supporting one contact (52) of each contact pair and having, at each pivotal connection (110) with a contact, a portion (270) defining a pocket (282) into which extends an end portion (284) of the associated contact, and in which are disposed restraining means (286, 288) cooperating with said end portion in such manner as to normally constrain the contact (52) to move together and in unison with the cross-bar (84), and to permit the contact to open independently of the cross-bar under the action of electrodynamic forces resulting from a high-level fault current flowing through the contacts. The cross-bar assembly is compact, requiring relatively little space, and at the same time provides reliable and fast contact operation./p[EP0145990A2]