Seat having back rest with different pivots for tilting and for folding level

In a seat assembly having a rigid seat frame, a seat cushion and a back rest supported by said frame,

• a first separable pivot connecting said back rest to said seat frame, said first separable pivot being on that transverse axis of said back rest about which said back rest is to be rotated for adjustment of tilt,
• locking means spaced from said first pivot and connecting said back rest and said seat frame in different selected degrees of tilt of said back rest,
• a second separable pivot on a different transverse axis of said back rest, said second separable pivot connecting said back rest to said seat frame during rotation of said back rest to a folded position over said seat cushion,
• said first separable pivot comprising a stud and a first arcuate bearing connected individually to said back rest and said seat frame, said first arcuate bearing being open in an upwardly direction, a guiding edge extending from an upper portion of said first arcuate bearing in a substantially horizontal direction such that said bolt is movable thereover for supporting said back rest until said bolt is free while said back rest is lifted slightly upwardly and then the upper portion of said back rest is tilted forwardly,
• said second pivot comprising a pintle and a second arcuate bearing connected individually to said back rest and said seat frame, said second pivot being separated while said back rest is in position for use,
• guiding means connecting said back rest to said seat frame, said guiding means cooperating with said guiding edge to position said pintle within said second arcuate bearing surface as said stud is removed from said first arcuate bearing and moved along said guiding edge, and said guiding means maintaining said pintle within said second arcuate bearing while said back rest is rotated to said folded position around said different transverse axis.