Electrical circuit switching device

An electrical circuit switching device for switching a predetermined first electrical circuit from a disconnection state to a conduction state, the electrical circuit switching device comprising:

• a housing;
• an igniter provided in the housing;
• a discharge chamber in which a combustion gas from the igniter is discharged when the igniter is actuated;
• a casing having conductivity and defining at least a part of the discharge chamber;
• and
• a pair of first conductor pieces arranged outside the discharge chamber in a state of being separated from each other, each of the pair of first conductor pieces forming a part of the first electrical circuit, wherein
• before actuation of the igniter, at least one of the pair of first conductor pieces and the casing are in a non-contact state with each other and thus the first electrical circuit is in a disconnection state, and
• when the igniter is actuated, the casing is deformed and thus expands to an outside of the discharge chamber by energy of a combustion gas generated by actuation of the igniter, the casing and each of the pair of first conductor pieces are brought into a state of being in contact with each other, and thus the first electrical circuit is brought into a conduction state.