Automobile seat

An automobile seat having a seat cushion and a seat back tiltably mounted on the seat cushion, comprising:

• a seat cushion frame;
• a side frame mounted on said seat cushion frame;
• a seat back frame mounted on said side frame so as to be rotatable within a limited angle;
• and
• a fastening member mounted on said seat back frame, with said side frame having an insertion hole defined therein through which said fastening member is to be inserted, and with said side frame also having an impact absorbing structure, said impact absorbing structure including
• (i) a first impact absorbing hole positioned rearwardly of said insertion hole,
• (ii) a second impact absorbing hole positioned rearwardly of said first impact absorbing hole, and
• (iii) a third impact absorbing hole positioned rearwardly of said second impact absorbing hole,
• wherein said seat back frame and said side frame are constructed and arranged such that
• (i) in a normal condition said seat back frame is fixed to said side frame by said fastening member, and
• (ii) when a load greater than a predetermined value is inputted from behind, a lower portion of said seat back frame is pushed upon a rearward movement of a seat occupant to thereby cause said fastening member to move rearwardly while deforming said impact absorbing structure, thus causing said seat back frame to rotate with respect to said side frame while absorbing an impact.