Patent attributes
An airbag includes plural bag portions respectively including two sheet members which are attached to each other, the plural bag portions arranged to be overlapped with each other in a thickness direction of the sheet member, and a welded portion at which the sheet members being in contact with each other are attached to each other. The welded portion includes a communication hole penetrating the sheet members which are in contact with each other to communicate the bag portions which are arranged to be overlapped with each other, and a rib portion arranged radially outward of the communication hole, the rib portion protruding in the thickness direction from a welded surface of the welded portion. The rib portion includes an annular rib surrounding the communication hole, and a cutout portion provided at the annular rib.
