Abstract: A vehicular seat includes at an upper part of a seat back an upper frame which extends in a widthwise direction of the seat back. An actuator unit which generates a drive force is attached along the upper frame. A headrest support frame is provided to the upper frame so as to be capable of moving in a front-and-back direction. When an acceleration equal to or above a predetermined value is applied to a vehicle by a collision from behind, a drive force generated by an operation of the actuator unit is transmitted to the headrest support frame. By moving the headrest support frame in a direction along which it approaches an occupant by using this drive force, a headrest supported to the headrest support frame moves frontward.

Abstract: In a vehicle seat, a central support member typically consisting of wire mesh or grid and supports most of the load of the vehicle occupant via spring members, and undergoes a relatively large displacement when the occupant is seated in the seat. Thus, by detecting the displacements of various parts of the central support member, preferably peripheral parts thereof, the magnitude of the total load and distribution of the load can be evaluated both reliably and accurately. Additionally, displacement sensors for measuring such large displacements are relatively inexpensive and easy to handle. Also, such sensors would not interfere with the existing seat designs, and would not be adversely affected by the equipment of the seat such as seat heaters.

Abstract: In a vehicle seat, a central support member typically consisting of wire mesh or grid and supports most of the load of the vehicle occupant via spring members, and undergoes a relatively large displacement when the occupant is seated in the seat. Thus, by detecting the displacements of various parts of the central support member, preferably peripheral parts thereof, the magnitude of the total load and distribution of the load can be evaluated both reliably and accurately. Additionally, displacement sensors for measuring such large displacements are relatively inexpensive and easy to handle. Also, such sensors would not interfere with the existing seat designs, and would not be adversely affected by the equipment of the seat such as seat heaters.

Abstract: A vehicular seat includes at an upper part of a seat back an upper frame which extends in a widthwise direction of the seat back. An actuator unit which generates a drive force is attached along the upper frame. A headrest support frame is provided to the upper frame so as to be capable of moving in a front-and-back direction. When an acceleration equal to or above a predetermined value is applied to a vehicle by a collision from behind, a drive force generated by an operation of the actuator unit is transmitted to the headrest support frame. By moving the headrest support frame in a direction along which it approaches an occupant by using this drive force, a headrest supported to the headrest support frame moves frontward.