Patent ID: 8702122

Claim:
An airbag configured to expand between two seats that are arranged in a vehicle in a direction of vehicle width, wherein the airbag is configured to be installed in a case located behind seating positions of the two seats, and when a gas is provided to the airbag, the airbag is inflated and expanded towards a front side of the vehicle so that an upper end and a lower end of the airbag are positioned on a front side relative to the case, wherein in an expanded state, an outline of a vertical cross section of the airbag taken along the vehicle width direction is shaped to have its widest portions located at a vicinity of a center in a height direction, and wherein in the expanded state, the upper end of the airbag has a substantially flat plateau so as to be securely abutted to an interior ceiling of the vehicle, respective outermost parts of the airbag are arranged between respective inner ends of headrests of the two seats when viewed in a front view from the vehicle front side, and the width of the airbag in the vehicle width direction is gradually decreased from the vicinity of the center in the height direction toward a top so that a space is secured between the airbag in the expanded state and a head and a neck of an occupant.