Construction of an adjustable seat

Adjustable seat (10), comprising: a seat back (11) is mounted pivotally on a seat cushion (12); a first seat back frame (13) which is arranged so that it forms one side of the seat back (11); a second seat back frame (14) which is arranged so that it forms the other side of the seat back (11); a first locking mechanism (21) for locking the first seat back frame (13) in a desired tilt position relative to the seat cushion (12); a second locking mechanism (22) for locking the first seat back frame (14) in the tilt position with respect to the seat cushion (12); a release lever (23) which is provided so that it pivots on the first locking mechanism (21); a first shaft (24) for unlocking the first seat back frame (13) which is locked by the first lock mechanism (21) by placing them in relation to the first locking mechanism (21) by the release lever (23) is rotated; a second shaft (25) for unlocking the ...