PURPOSE: To provide a highly reliable small gas-blast circuit breaker having a closing resistance by which electrical insulation between an arc extinguishing chamber and an closing resistance contact point part can be secured and in which displacement or stress caused in an closing contact point fixing part due to impact force received in the case of closing the closing resistance contact point part can be restrained to the possible minimum level.
CONSTITUTION: There are provided an arc extinguishing chamber 4 housed in an insulating gas sealed container 2, a closing resistance 27 connected electrically in parallel to this arc extinguishing chamber to restrain over-voltage while being closed and an closing resistance contact point part 5 connected electrically in series to this closing resistance. A fixing part 32 of the closing resistance contact point part is supported with a metallic support member 35 having large longitudinal elastic modulus to a fixing part 6 of the arc extinguishing chamber, and is also insulated electrically by means of an insulating member 34. The insulating member is arranged so as to coincide with the axial direction of the fixing part of the closing resistance contact point part. A spring 33 of the fixing part of the closing resistance contact point part is formed of ceramic.
NAKAMOTO TETSUYA
AOYANAGI AKIRA
