US Patent 7357083 Initiator

An initiator is incorporated in an inflator in order to trigger the inflator through propagation of flame from an initiating explosive to a gas generator of the inflator. The initiator includes a closed-bottomed tubular capsule for accommodating the initiating explosive. A tubular portion of the capsule includes a plurality of rupture-accelerating means (grooves each having a V-shaped cross section) for accelerating rupture upon ignition of the initiating explosive, whereby flame propagates from the initiating explosive to the gas generator of the inflator along a plurality of directions.