Conduction breaking device

A conduction breaking device for breaking conduction between a pair of devices in an electric circuit, the conduction breaking device comprising:

• an elongated plate-shaped metal conductive body, which extends between the devices in the electric circuit and has a cuttable portion in part in a longitudinal direction;
• a cutting chamber and a gas generator, which face each other to sandwich the cuttable portion in the thickness direction of the cuttable portion;
• and
• a cutter block, which is movable in the thickness direction of the cuttable portion, wherein
• the cutting chamber has a polygonal opening that faces the cuttable portion,
• at least one side of the opening forms a cutting edge portion,
• the gas generator generates gas to move the cutter block in the thickness direction of the cuttable portion, thereby cutting the cuttable portion between the moving cutter block and the cutting edge portion,
• the cutter block includes a block leading portion and a block trailing portion, the block leading portion covering a surface of the cuttable portion that faces the cutting chamber, and the block trailing portion covering a surface of the cuttable portion that faces the gas generator, and
• the cutter block is attached to the cuttable portion;
• and before generation of gas by the gas generator, a part of the cutter block is located in the cutting chamber and at a position close to the cutting edge portion in a direction along the surface of the cuttable portion.