Abstract: The invention concerns a seat articulating device comprising a seat and a back capable of pivoting relative to the back seat about a pivot pin (A1) into a plurality of positions, in particular a nominal position wherein the back is substantially vertical and a shelf position wherein the back is folded down on the seat, said device comprising: a flange (3) designed to support the back pivoting relative to the pivot pin (A1) including arc-shaped teeth having a radius R centered on the pivot pin (A1); a concave toothed segment (12) capable of being linked to the seat, oscillating relative to a pivot pin (A2) between a locking position wherein it co-operates with the teeth of the flange (3) and an unlocking position wherein it is spaced apart from the flange teeth and allows the flange (3) to rotate.

Abstract: The adjustment device comprises a toothed quadrant connected to the sitting surface, and a toothed quadrant which is connected to the back and which can be meshed into the toothed quadrant connected to the sitting surface, in a locked configuration of the seat, and can be demeshed from the toothed quadrant connected to the sitting surface, in an unlocked configuration of the seat, making it possible to adjust the angular position of the back with respect to the sitting surface, an element which possesses a stepped quadrant having a first convex surface and at least one second convex surface, each defining an angular sequence, which are connected to one another by a stop surface, a pawl possessing a tooth capable of following each convex surface until it comes to bear against a stop surface, and an element to pivot the pawl in order to release the tooth from a stop surface, so as to cause the seat to change from one angular sequence to the next sequence.

Abstract: The adjustment device comprises a toothed quadrant (7) connected to the sitting surface, and a toothed quadrant (16) which is connected to the back and which can be meshed into the toothed quadrant (7) connected to the sitting surface, in a locked configuration of the seat, and can be demeshed from the toothed quadrant (7) connected to the sitting surface, in an unlocked configuration of the seat, making it possible to adjust the angular position of the back with respect to the sitting surface.

Abstract: A device for adjusting a double-jointed seatback by a single control. A seat pan structure is joined on at least one side to a convex toothed sector centered on a first joint. A seatback structure is joined to two arms that extend on either side of a housing. The arms are articulated on a second joint mounted upon the housing, and are joined to a concave toothed sector centered on the second joint. The housing contains an upper toothed locking plate and a lower toothed locking plate. Between the two locking plates, a pivoting cam connects to a single control device. The upper toothed locking plate is joined to a stop arm that extends in the housing towards a semicircular stop located on the lower toothed sector. The semicircular stop is provided to resist the unlocking of the locking plate except when the seatback is in the maximally advanced position.