To enhance degree of freedom of layout with a simple construction while preventing a submarine phenomenon by projecting the piston from the cylinder on detection of impact on a vehicle through generation of gas, projecting a slide prevention member upward from the seat cushion and maintaining that projected state by locking.
While running, gas is generated on detection of impact such as from a collision and an internal pressure of a cylinder is quickly increased to project a piston member 9 from the cylinder instantaneously. A link member 3 connected to a free end of the piston member 9 is rotated clockwise to move a long arm portion 3a together with a bar 6 upward so as to prevent a submarine phenomenon of a passenger by swelling of a seat. When generation of gas is over and a driving force of a power unit 7 has disappeared, owing to a ball one-way lock mechanism, the submarine phenomenon prevention effect is maintained without the bar 6 having moved upward being returned downward. Accordingly, the submarine phenomenon is prevented upon impact, while making the construction simple and enhancing the degree of freedom of the layout.
YAMAGUCHI HIRONORI
OI TOMOHARU
KOUZO MINORU
