US Patent 9428137 Seat cushion airbag system

A seat cushion airbag system may include: a cushion body installed on a seat of a vehicle, unfolded by receiving gas from an inflator, and including a rear chamber which lifts the rear part of the body of a passenger and a front chamber which lifts the front part of the body of the passenger while inflating more than the rear chamber; and an unfolding restriction unit installed between the rear chamber and the front chamber, and having a vent hole through which gas is passed.