Inflator for air bag

An inflator for an air bag comprising an inflator base portion provided with an ignition means which receives an ignition current to be activated, an inflator housing and a gas discharging port which discharges a gas inside the inflator housing to the outside at the time of activation, and

• a tubular case portion which covers the entire or part of an outside of the inflator housing to cover at least the gas discharging port,
• wherein only the axial both sides of a periphery of the case portion is provided with a gas ejecting port unevenly and the inner space of the case portion is sealed off but communicates the outside only through the gas ejecting port,
• a gas communication space which is an annular space having substantially a uniform width and guiding a gas discharged from the gas discharging port to the gas ejecting ports is secured between the inflator housing and the case portion, and
• in the gas ejecting ports provided at the axial both sides of the case portion, a total opening area (A′) of the gas ejecting port provided at one axial end portion is different from a total opening area (B′) of the gas ejecting port provided at the other axial end portion.

An air bag system including an air bag, an inflator for an air bag for inflating the air bag, and a tubular case portion which covers the whole or part of an outside of the inflator for an air bag, wherein

• an air bag has a first gas introducing portion and a second gas introducing portion,
• the case portion covers at least a gas discharging port provided in the inflator for an air bag, only the axial both sides of a periphery of the case portion is provided with a gas ejecting port unevenly and the inner space of the case portion is sealed off but communicates the outside only through the gas ejecting port,
• a gas communication space which is an annular space having substantially a uniform width and guiding a gas discharged from the gas discharging port to the gas ejecting ports is secured between an outer surface of the inflator housing and the case portion,
• in the gas ejecting ports provided at the axial both sides of the case portion, a total opening area (A′) of the gas ejecting port provided at one axial end portion is different from a total opening area (B′) of the gas ejecting port provided at the other axial end portion, and
• the gas ejecting ports provided at the axial both sides of the case portion are each connected to the different gas introducing ports.

An air bag system including plural air bags, an inflator for an air bag for inflating the air bags, and a tubular case portion which covers the whole or part of an outside of the inflator for an air bag, wherein

• the case portion covers at least a gas discharging port provided in the inflator for an air bag, only the axial both sides of a periphery of the case portion is provided with a gas ejecting port unevenly and the inner space of the case portion is sealed off but communicates the outside only through the gas ejecting port,
• a gas communication space which is an annular space having substantially a uniform width and guiding a gas discharged from the gas discharging port to the gas ejecting ports is secured between an outer surface of the inflator housing and the case portion,
• in the gas ejecting ports provided at the axial both sides of the case portion, a total opening area (A′) of the gas ejecting port provided at one axial end portion is different from a total opening area (B′) of the gas ejecting port provided at the other axial end portion, and
• the respective plural air bags is mounted to the respective gas ejecting ports formed at axial both sides of the case portion of the inflator for an air bag.