Hinge mechanism for a vehicle seat, and a vehicle seat equipped with such a mechanism

1/ A hinge mechanism for a vehicle seat, said hinge mechanism comprising:

• first and second cheek plates mounted to pivot relative to each other about a common pivot axis, the second cheek plate being provided with a first set of teeth forming at least an arc of a circle centered on the pivot axis;
• N locking members, each of which is provided with a second set of teeth having an angular pitch identical to the angular pitch of the first set of teeth, each locking member being mounted to move on the first cheek plate between firstly an active position in which the second set of teeth of each locking member is in engagement with the first set of teeth of the second cheek plate so as to prevent the first and second cheek plates from moving relative to each other, and secondly a retracted position in which the second set of teeth of each locking member does not co-operate with the first set of teeth of the second cheek plate so as to enable the first and second cheek plates to pivot relative to each other;
• N guides secured to the first cheek plate, each guide being associated with a locking member and serving to guide said locking member with operating clearance, said locking member following an axis of displacement that is substantially rectilinear between the active and the retracted positions;
• and
• a control device adapted to place the N locking members either in the active position, or in the retracted position;
• wherein (N−1) guides are disposed in a manner such that the (N−1) locking members that are associated with them move along (N−1) respective axes of displacement that coincide with (N−1) radial directions which intersect the pivot axis, and wherein the last guide is disposed in a manner such that the locking member that is associated with it moves along an axis of displacement that is parallel to and offset relative to a radial direction that intersects the pivot axis.