Electric circuit switching device

An electric circuit switching device configured to switch a predetermined first electric circuit from an interrupted state to a conductive state upon actuation, the electric circuit switching device comprising:

• a housing;
• an igniter provided in the housing and configured to release a combustion gas upon actuation;
• a tubular space formed in the housing and extending in one direction;
• a projectile having conductivity, positioned at a first position in the tubular space in an initial state before actuation of the igniter, and configured to be projected in a predetermined projecting direction along the tubular space by energy of the combustion gas;
• a pair of first conductor pieces provided inserted, in a spaced apart state, into the tubular space at a second position closer to the projecting direction side than the first position, and forming part of the first electric circuit in cooperation with each other;
• and
• a support disposed closer to the projecting direction side than the first position in the tubular space, and configured to receive, at the second position, the projectile projected by actuation of the igniter, wherein
• when the igniter is actuated and the projectile is projected, the projectile deforms by collision with the support, the projectile and each of the pair of first conductor pieces come into contact with each other, and the projectile becomes engaged with the pair of first conductor pieces, switching the first electric circuit from the interrupted state to the conductive state.