Patent ID: 7403087
Filing Date: 2008-07-22
Classification: H01H

Abstract:
1. A pressure trip device for a circuit breaker, comprising: a plurality of single pole switching units, each unit corresponding to each electric phase having a movable contactor and fixed contactors in an insulated case in order to switch an electric circuit for each electric phase, an arc gas exhaust port, and connected to one another by a shaft; a switching mechanism connected to one of the single pole switching units that provides contact and separation between the movable contactor of the connected single pole switching unit and the fixed contactor of the connected single pole switching unit; a trip bar connected to the main circuit switching unit that trips the switching mechanism; a gas pressure shooter facing the trip bar, and longitudinally movable between a position that rotates the trip bar by pushing and a position separated from the trip bar; and a protrusion wall portion having a pair of wall portions facing each other and perpendicularly extending from at least one outer surface of each case of the single pole switching units, having one wall portion connecting lower ends of the pair of wall portions to each other, and forming a gas pressure storing space that supports the gas pressure shooter to be longitudinally movable and connected to the arc gas exhaust port; wherein the pair of wall portions of the protrusion wall portion are horizontally spaced from each other a predetermined distance to form an opening at each upper end thereof so that the gas pressure shooter can be longitudinally movable, and are respectively provided with a vertical groove wall portion having a limiting protrusion that limits a movable distance of the gas pressure shooter between a position that rotates the trip bar by a pressurization and a position separated from the trip bar.