Patent ID: 6787725
Filing Date: 2004-09-07
Classification: H01H

Abstract:
A switching mechanism of a circuit breaker for a gas insulated switchgear comprising:a fixed arc contactor electrically connected to an electric power source or to a load; a main cylinder fixedly installed to face the fixed arc contactor in a vertical direction; a movable cylinder movably installed on an upper part of the main cylinder, the movable cylinder having a compressing chamber containing insulating gas therein; a cylinder rod extending from a predetermined position of an inner lower part of the main cylinder toward inside of the movable cylinder, and being connected to the movable cylinder so as to be movable with the movable cylinder; a movable arc contactor installed on an upper part of the cylinder rod and contacted/separated selectively to/from the fixed arc contactor depending on the vertical movement of the cylinder rod; a nozzle installed on an upper part of the movable cylinder for injecting the insulating gas in the compressing chamber; and a movable sealing means installed between the movable cylinder and the cylinder rod, and movable in a vertical direction for providing the compressing chamber of which a volume can be varied, wherein the movable sealing means comprises; a movable sealing member located between the cylinder rod and the movable cylinder to seal the compressing chamber and moved along with an outer circumferential surface of the movable cylinder; and a spring installed on a position supporting the movable sealing member to move the movable sealing member elastically according to pressure status of the compressing chamber, wherein the movable sealing member includes a protruded portion formed on a position facing an upper end portion of a spring seat for restricting the vertical movement of the movable sealing member.