Seat with a tilting and folding back

Claim 1

A seat (10) comprising, in combination; a base (11); a back (12) carried by a back support (120) tiltable relative to said base (11) between an upright position and other tilted positions changeable at will; a frame (20) having on each of two opposite sides thereof a pair of end plates, each pair having a first end plate (21), for accommodating said base (11), and a second end plate (22) for accommodating said back support (120); `tilt-adjustment means (30) inserted between said first and second end plates (21, 22) and movable between a normal blocked locking position, toward which said means (30) is normally biased in order to fix a relative position of said back (12) and base (11), and a transitional released free position to allow an adjustment of a tilted position of said back (12) relative to said base (11), said tilt-adjustment means (30) being provided with a control means (31) for changing the position of said tilt-adjustment means; and a pivot mechanism means (50), placed between said second end plate (22) and back support (120), for making said back (12) movable between a first normal position, where said back (12) serves as a back rest, and a second folded position where said back (12) serves as a shelf; said pivot mechanism means (50) comprising: at least one cheek (51) carried by said back support (120) and rotatably mounted on said second end plate (22) for rotation about an axis between said first and second positions; a lock means (52) having a catch and a bolt cooperating with said cheek (51) and said second end plate (22) and movable between a first active position, toward which it is normally biased to fix said back (12) in one of its said first normal and second folded positions, and a second inactive position to tilt said back (12); a linkage means (53) connecting and controlling said tilt-adjustment means (30) and said lock means (52) either in order to act on said control means (31) to move said tilt-adjustment means (30) from one to the other of its said usual and transitional positions, or in order to act and move said lock means (52) from its said active position to its said inactive position; and safety device means (54), pivotally mounted on said second end plate (22), and biased by a spring (544) for contacting and cooperating with said first end plate (21) and for acting on said cheek (51) to lock said cheek (51) and prevent any rotation thereof which would place said back (12) in its said shelf second folded position when said back (12) is not placed in its upright position beforehand.