Patent ID: 7922192

Claim:
A side curtain air bag, which has chambers expanded by gas supplied from an inflator, and expands and develops in a curtain shape at side part of a vehicle so as to protect vehicle occupants, the side curtain air bag comprising: a primary chamber which expands so as to protect an occupant; a secondary chamber which applies tension on the side curtain air bag after the side curtain air bag is expanded and developed; and a set of tethers, each having one end attached to the side curtain air bag at a joint end and the other end attached to the vehicle at a fixation end, in a forward and backward direction of the vehicle, wherein, the primary chamber has a first opening through which gas is supplied from the inflator, and is expanded by the inflow of the gas from the inflator, the secondary chamber has a second opening through which gas is supplied from the inflator, and is expanded by the inflow of the gas from the inflator, the second opening is smaller in size than the first opening so that the secondary chamber expands later than the primary chamber, when the side curtain air bag is expanded and developed, the primary chamber and the secondary chamber are disposed such that a portion or all of the primary and secondary chambers overlap one of a virtual band region formed of a first virtual line connecting the respective fixation ends of the one set of tethers and a second virtual line connecting the respective joint ends of the one set of tethers, the virtual band region formed of the first virtual line connecting respective upper ends of attachments parts of the one set of tethers and the second virtual line connecting respective lower ends of the attachment parts of the one set of tethers, and the virtual band region formed of the first virtual line connecting the upper end of the attachment part of one tether and the fixation end of the other tether, and the second virtual line connecting the respective lower ends of the attachment parts of the one set of tethers, and the secondary chamber is, in the virtual band region, disposed in front of or behind the primary chamber in a forwardmost portion or a rearmost portion of the airbag.