Apparatus for preventing rotation of seat frame for vehicle

An apparatus for preventing rotation of a seat frame for a vehicle having the seat frame that includes an inner link portion and an outer link portion that is provided with a height adjustment device to adjust a height of a seat and a rack gear link, comprising:

• a height link, wherein a first end portion of the height link is pivotally connected to a set bracket and a second end portion of the height link is pivotally connected to a cushion side member;
• and
• a rotation prevention link provided on the inner link portion wherein a first end portion of the rotation prevention link is pivotally hinged to the height link and a second end portion of the rotation prevention link is movably installed on the set bracket,
• wherein a first end portion of an elastic member is provided on the second end portion of the rotation prevention link and a second end portion of the elastic member is fixed to the height link, and
• wherein:
• while an inertial force acts on the rotation prevention link in one direction of the vehicle in a front vehicle collision, the second end portion of the rotation prevention link is inserted and locked in a gear portion to suppress rotation of the rotation prevention link and the height link, and
• while an inertial force acts on the rotation prevention link in the other direction of the vehicle in a rear vehicle collision, the rotation prevention link is pressed toward the set bracket by rotation of the height link and the second end portion of the rotation prevention link is pressingly supported on a lower surface of a slot framed on the set bracket and slidably receiving the second end portion of the rotation prevention link to suppress the rotation of the rotation prevention link and the height link by spring force of the elastic member.