Side airbag device

A side airbag device for providing protection in a space between a vehicle occupant and a body side of a vehicle when the occupant is seated on a vehicle seat in a passenger compartment, the side airbag device comprising:

• a gas generator;
• and
• an airbag for unfolding and inflating by gas supplied from the gas generator, wherein the airbag unfolds and inflates in a space diagonally in front of the occupant seated on the seat, the airbag including:
• an airbag body for unfolding and inflating beside the occupant in the space between the occupant and the vehicle body side, wherein the airbag body includes an upper inflation portion for protecting a head to neck region of the occupant;
• and
• a projecting portion for unfolding and inflating inward of the vehicle from the upper inflation portion
• a pair of base cloths sewn together into the shape of a bag to form the airbag, one base cloth being located closer to the occupant and the other cloth being located farther from the occupant when the air bag is unfolded and inflated;
• a boundary between the airbag body and the projecting portion;
• a bent portion located at the boundary, the projecting portion being bent from the bent portion relative to the airbag body when the airbag is unfolded and inflated, the bent portion defining a distal end of the airbag body, and the airbag body including a basal end located opposite the distal end, in which the base cloth farther from the occupant between the distal and basal ends of the air bag body is longer than the base cloth closer to the occupant between the distal and basal ends of the air bag body, the bent portion defining a basal end of the projecting portion, and the projecting portion including a distal end located opposite the basal end of the projecting portion, in which the base cloth farther from the occupant between the distal and basal ends of the projecting portion is shorter than the base cloth closer to the occupant between the distal and basal ends of the projecting portion;
• and
• a starting seam arranged in the bent portion, the starting seam being formed by sewing together the base cloths so that the base cloths have different lengths at the air bag body and the projecting portion.