US 12,217,921 B2
Vacuum circuit breaker
Yusuke Tomizawa, Tokyo (JP); Takuma Sasai, Tokyo (JP); and Masao Akiyoshi, Tokyo (JP)
Assigned to MITSUBISHI ELECTRIC CORPORATION, Tokyo (JP)
Appl. No. 17/918,576
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed May 20, 2020, PCT No. PCT/JP2020/019994
§ 371(c)(1), (2) Date Oct. 13, 2022,
PCT Pub. No. WO2021/234870, PCT Pub. Date Nov. 25, 2021.
Prior Publication US 2023/0145798 A1, May 11, 2023
Int. Cl. H01H 33/662 (2006.01); H01H 33/664 (2006.01); H01H 33/666 (2006.01)
CPC H01H 33/66238 (2013.01) [H01H 33/664 (2013.01); H01H 33/666 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A vacuum circuit breaker comprising:
a fixed contactor;
a movable contactor contactable with and separable from the fixed contactor;
a container accommodating each of the fixed contactor and the movable contactor and holding an inside thereof in vacuum;
a movable shaft extending in an axial direction from an outside of the container and connected to the movable contactor to drive the movable contactor by moving in the axial direction;
a plate-shaped member attached to the movable shaft inside the container and extending around an axis of the movable shaft;
a coupling bellows
including
a first bellows expandable and contractible in the axial direction and
a second bellows positioned side by side with the first bellows in the axial direction and expandable and contractible in the axial direction, and having a spring constant higher than a spring constant of the first bellows, and
airtightly connecting the plate-shaped member and an inner surface of the container on an outer side of the movable shaft;
a coupling member extending in a radial direction of the movable shaft so as to protrude to at least one of an inner peripheral side and an outer peripheral side of each of the first bellows and the second bellows, joined to each of the first bellows and the second bellows adjacent to each other, and including a hole inserted with the movable shaft so as to be movable in the axial direction; and
a pressing member disposed on the inner peripheral side or the outer peripheral side of the first bellows, to move in the axial direction toward the coupling member along with movement of the movable shaft in a direction in which the movable contactor is separated from the fixed contactor, to come into contact with the coupling member and thereafter press the coupling member, thereby contracting the second bellows,
wherein when the first bellows contracts and after the pressing member and the coupling member come into contact with each other, the first bellows does not contract, and the second bellows contracts until the opening of the vacuum circuit breaker is completed.