US Patent 11279270 Occupant protection system and method including seatback

A seat for a vehicle may include a seatback including an intermediate portion including a first portion having a first stiffness and a second portion including a second material different than a first material of the first portion, such that the seatback quickly couples an associated occupant and dissipates as much energy as possible. The intermediate portion may be configured such that as at least a portion of the back of an occupant of the seat pushes against a front surface of the seatback and the seatback is at least partially compressed, a reaction force from the seatback against at least a portion of the back of the occupant increases from a minimal reaction force to a first reaction force corresponding to a first displacement, and thereafter the reaction force decreases to a second reaction force as displacement of the front surface of the seatback further displaces.