Seat drive device

A seat drive device that is built in a seat including a central portion and a side support located outside the central portion in a width direction, and drives the side support, the seat drive device comprising:

• a base fixed to the seat;
• a paddle that is rotatably supported with respect to the base and configured to rotate in an unfolding direction to displace the side support toward a seating region of a user;
• and
• an air bag disposed between the base and the paddle, wherein the air bag is configured to rotate the paddle in the unfolding direction when it is expanded by an air supply,
• wherein the paddle includes a pressing portion that is configured to press the side support from inside upon rotation in the unfolding direction, and
• an arm that is rotatably supported with respect to the base and extends toward the pressing portion,
• wherein a rotation axis of the paddle is located in a central portion of the seat,
• wherein the arm is curved toward a retraction direction that is a direction opposite to the unfolding direction, and
• wherein the seat drive device includes a fully retracted position, and the curved portion of the arm is configured to penetrate the base when the seat drive device is in the fully retracted position.