Patent ID: 8210608
Filing Date: 2012-07-03
Classification: B60N,F16F

Abstract:
1. A vehicle seat having a headrest placed at the top of a backrest to be in contact with the back of a riding person for protecting a head of the riding person, an energizing mechanism for energizing the headrest to move toward the front side of the vehicle, a stopping mechanism to stop the energizing of the energizing mechanism not to cause movement of the headrest toward the front side of the vehicle, an external force receiving pad which is placed inside the backrest and turns on receiving an external force given to the backrest; a releasing mechanism which releases the stopping of the stopping mechanism to start the energizing mechanism, and a damper which is placed inside the backrest and drives the releasing mechanism in conjunction with turning of the external force receiving pad, the damper comprising: a vessel having a cylindrical chamber therein; a viscous fluid filled in the cylindrical chamber; a slider member placed in the cylindrical chamber, dividing the chamber into a first small room and a second small room, having a hole connecting between the first small room and the second small room, and being movable toward both the first small room and the second small room in the cylindrical chamber; a turn member placed in the first small room, turning in conjunction with a turn of the external force receiving pad, and converting a predetermined direction turning force into a driving force of the slider member in a direction of the second small room or transmitting the predetermined direction turning force to the slider member; a partition member having a communication path between the first small room and the second small room, engaged with the slider member to open and close the hole of the slider member by a pressure difference of the viscous fluid between the first small room and the second small room, opening the hole of the slider member to pour the viscous fluid from the first small room to the second small room through the hole of the slider member upon moving of the slider member toward the first small room, and closing the hole of the slider member to generate a throttle resistance for limiting a flow of the viscous fluid from the second small room to the first small room the through the hole upon moving of the slider member toward the second small room; a coiled spring for energizing the slider member toward the turn member; and a cap fixed to the vessel by engaging with the slider member, blocking an opening at one end of the vessel, and held by the vehicle seat rotatably and connected with the releasing mechanism to start the releasing mechanism in conjunction with turning relative to the vehicle seat, wherein, when the turn member is turned at a turning rate less than a predetermined turning rate, the slider member moves at a lower rate than a predetermined rate toward the second small room in the cylindrical room of the vessel with damping the turn of the turn member by the throttle resistance being decreased of the flow of the viscous fluid from the second small room to the first small room, and when the turn member is turned at a turning rate more than the predetermined turning rate, the move of the slider member toward the second small room is prevented and the slider member is rigid-coupled with the turning member to turn together with the turning member by the throttle resistance being increased of the flow of the viscous fluid from the second small room to the first small room.