Method for assembling vehicle seat with cushion plate

A method of assembling a vehicle seat, comprising:

• providing a seat back frame;
• forwardly movably connecting a headrest for supporting a head of a seat occupant to the seat back frame;
• mounting a rear-end collision detector to the seat back frame at a position behind the seat occupant, wherein the rear-end collision detector detects rearward movement of the seat occupant and moves rearward;
• and
• operatively connecting the rear-end collision detector to the headrest such that the rearward movement of the rear-end collision detector forwardly moves the headrest;
• disposing a link member at a position lateral to the rear-end collision detector;
• mounting a bracket to a side frame that constitutes a side portion of the seat back frame;
• mounting a link support shaft to the bracket, with the link member being mounted to the link support shaft;
• forming a front extending portion that inwardly extends in a right-to-left direction and is formed at a front end of a lateral face of the side frame;
• and
• forming a rear extending portion that inwardly extends in the right-to-left direction and is formed at a rear end of the lateral face of the side frame;
• wherein:
• at least a part of the bracket is disposed on the lateral face of the side frame and between the front extending portion and the rear extending portion;
• a protruding portion inwardly protruding is formed at a portion of the lateral face of the side frame that faces at least the part of the bracket, the link support shaft being disposed at a same height as the protruding portion;
• at least the part of the bracket is attached to the protruding portion;
• the link member is disposed overlapping, in a right-to-left direction, with the protruding portion and extends downward from the link support shaft;
• a lower end portion of the link member is swingably connected to an end of the rear-end collision detector through a connecting shaft;
• the bracket comprises a link shaft supporting face that extends from a side frame side towards an inner side of the seat, and a first attachment portion and a second attachment portion for being attached to the side frame;
• and
• the second attachment portion is disposed closer to a bottom of the seat than the first attachment portion and extends downward from the link shaft supporting face along the protruding portion to be attached to the protruding portion.