Vehicle seat having a backrest equipped with shock absorbing means

Seat intended to be fixed to the floor of a vehicle, having a seat part incorporating a lower frame, and a backrest incorporating an upper frame secured to the lower frame by at least one fastener that enables the backrest to tilt about a transverse axis of the seat, this fastener comprising:

• a link rod having a first end connected to the lower frame by a first pivot link of axis parallel to the transverse axis, and having a second end connected to the upper frame by way of a second pivot link of axis parallel to the transverse axis;
• each pivot link having a rotation brake and/or a system of stops limiting its rotation amplitude;
• a pivot link including a brake having a screw passing through one end of the link rod while being screwed into a boss, in order to hold tight the link rod end to generate a friction torque during reaction to a rotation of the end of the link rod in relation to the boss to brake this rotation;
• a sacrificial mechanical link that connects the lower frame to the upper frame while being located opposite the link rod.