Abstract: There is described a vehicle seat, notably for motor vehicle, comprising a bottom and a back, that back portion at least whereagainst the back of a person taking place in the seat bears, so cooperating with resilient members as to be swingable about a fixed point relative to the bottom, exclusively with an up-and-down motion, which seat is provided with means to limit conveying from the seat bottom, vibrations with a frequency higher than 10 Hz to that back portion whereagainst said person back does bear.

Abstract: A seat for a vehicle, preferably a motor vehicle, includes a bottom and a back. The back of a passenger bears against the back of the seat. The back of the seat is mounted to swing together with the back of the passenger in a vertical direction. The seat back has a natural frequency which is higher than the natural frequency of the seat bottom when bearing a passenger.

Abstract: Seat for vehicle, particularly a motor vehicle, including a seat and a back rest of which the part against which rests the back of a person sitting in the seat has a support which is mounted so as to oscillate together with the back of said person, substantially in the plane of the back rest and in an upward and downward direction with respect to the seat.