Abstract: A vehicle seat device includes an SB main frame that is joined to a seat cushion via a reclining shaft; an SB subframe that is swingable with respect to the SB main frame at least about a roll axis; a backrest that is installed on the SB subframe; and a lower support wire and an upper support wire that limit rearward movement of the SB subframe and allow movement of the SB subframe about the roll axis. A straight line connecting between the front end and the rear end of the lower support wire is inclined with respect to a normal line so as to rise toward the front, the normal line being normal to a straight line connecting between an upper end of the SB main frame and the reclining shaft.

Abstract: A vehicle seat device includes an SB main frame that is joined to a seat cushion via a reclining shaft; an SB subframe that is swingable with respect to the SB main frame at least about a roll axis; a backrest that is installed on the SB subframe; and a lower support wire and an upper support wire that limit rearward movement of the SB subframe and allow movement of the SB subframe about the roll axis. A straight line connecting between the front end and the rear end of the lower support wire is inclined with respect to a normal line so as to rise toward the front, the normal line being normal to a straight line connecting between an upper end of the SB main frame and the reclining shaft.

Abstract: A headrest is supported by an upper lateral member and a lower lateral member of a seat frame. A headrest stay is inserted through each of guide slots, both of which are formed in both the upper lateral member and the lower lateral member, and an extension wire is hooked on a lower end of the headrest stay. In a rear-collision, a seat back is retreated by a force received from a seated passenger, and a tension of the tension wire is accordingly loosened, which causes the headrest to be tilted forward by an urging force of tilt springs.

Abstract: A headrest is supported by an upper lateral member and a lower lateral member of a seat frame. A headrest stay is inserted through each of guide slots, both of which are formed in both the upper lateral member and the lower lateral member, and an extension wire is hooked on a lower end of the headrest stay. In a rear-collision, a seat back is retreated by a force received from a seated passenger, and a tension of the tension wire is accordingly loosened, which causes the headrest to be tilted forward by an urging force of tilt springs.

Abstract: A vehicle seat apparatus includes a seat portion, a seatback arranged on a rear side of the seat portion, a seat portion supporting mechanism that supports the seat portion such that a right side and a left side of the seat portion are able to move relative to one another in a vertical direction of the vehicle seat apparatus, and a seat portion restoring force generating mechanism that generates a restoring force that returns the seat portion to an original position when the seat portion rotates.

Abstract: A vehicle seat apparatus includes a seat portion, a seatback arranged on a rear side of the seat portion, a seat portion supporting mechanism that supports the seat portion such that a right side and a left side of the seat portion are able to move relative to one another in a vertical direction of the vehicle seat apparatus, and a seat portion restoring force generating mechanism that generates a restoring force that returns the seat portion to an original position when the seat portion rotates.