Patent ID: 7703852

Claim:
A reclining mechanism for a vehicle seat comprising: a guide plate secured to one of a seat base or a seat back; a pivotal plate secured to the other of the seat base or seat back and that is pivotally connected to the guide plate about a pivotal axis, the pivotal plate has a plurality of internal gear teeth; a cam having a plurality of cam lobes is pivotally disposed on a hub between the guide plate and the pivotal plate; a plurality of locking elements cooperate with the guide plate and the cam and are moved relative to the guide plate, the locking elements each have an external gear segment that extend radially outwardly and cooperate with the internal gear teeth, the locking elements each have a cam following engagement surface that has a plurality of lands that cooperate with the cam lobes, wherein rotation of the cam causes the cam lobes to engage the cam following engagement surfaces of the locking elements to hold the external gear segments of the locking elements in engagement with the internal gear teeth in a locked position; a control plate is secured to the hub and is manually rotated by the hub, the control plate has a plurality of slots that each receive an axially extending protrusion that is provided on one of the locking elements to draw the locking elements radially inwardly to disengage the external gear segments from the internal gear teeth of the pivotal plate in an unlocked position; at least two springs are attached to the guide plate at spaced locations relative to the axis and engage the cam to normally bias the cam pivotally to drive the external gear segments into engagement with the internal gear teeth, the springs are disposed in an axially recessed portion of the guide plate and are enclosed between the guide plate and the pivot plate; wherein the cam engages each locking element to drive the external gear segments into the internal gear segments when the reclining mechanism is in the locked position; and wherein an arcuate rib is provided on the pivotal plate that engages the axially extending protrusions on the locking elements, wherein the rib prevents the locking elements from returning to the locked position in certain radial alignments of the pivotal plate relative to the guide plate.