A power reclining device for use in a seat includes a reclining mechanism for adjusting a tilt angle of a seat back frame with respect to a seat cushion frame and a pre-assembled power unit having a gear train. The pre-assembled power unit has a hole for receiving an end of a rotating shaft of the reclining mechanism when it is attached to a lower arm of the seat, whereby a gear train is established for a smooth transmission of rotational torque from an electric motor to the rotating shaft.

A seatback recliner mechanism incorporated into a vehicle, the seat including a seat bottom and a pivotally engaged seatback. The recliner mechanism includes a pair of lower supports forming a part of the seat bottom and secured to at least one of first and second sides of the seat bottom. A first gear is fixed between the lower support and at a generally upper end and a pair of upper supports are pivotally secured to the lower supports and include a second rotatable gear meshingly engaged with the first gear. The seatback includes an upper arm pivotally secured to the upper support in coaxial fashion relative to a third rotatable gear meshingly engaged with the second gear. A first lever is operative to pivot the upper support relative the lower support over a specified range of forward incline and rearward recline. A second lever is operative to pivot the upper arm, relative to the upper support, to a substantially forward and horizontal position. A third lever unseats and rotates an intermediate plate, disposed between the upper and lower support plates and operatively engaged to the upper support plates in the released position, to a predetermined and forwardly inclined position.

A power reclining device for use in a seat having a seat cushion and a pivotal seatback includes two base plates and two pivoting arms. The base plates are respectively secured to laterally opposed side rear portions of the seat cushion. The pivoting arms are respectively secured to laterally opposed side lower portions of the seatback. The pivoting arms are rotatably connected to the base plates by two rotating shafts, respectively. The base plates, the pivoting arms and the rotating shafts constitute laterally spaced first and second hinge units by which the seatback is permitted to pivot about a common axis of the rotating shafts. A connecting shaft is interposed between and secured to the rotating shafts to constitute a shaft unit. A flat spiral spring is incorporated with the first hinge unit for biasing the pivoting arms to pivot about the common axis in the rearward direction relative to the base plates. The flat spiral spring is positioned between the hinge units and arranged to be disposed about the shaft unit. A spring-supporting bracket is secured to the base plate of the first hinge unit for supporting the spring. An electric motor is operatively connected to the shaft unit for rotating the same when energized.

An adjustment device for seats, particularly motor vehicle seats, having a transmission, particularly a planetary gear transmission, and further including a drive shaft (2) which can be rotated by a drive device (4) coupled therewith. The mass moment of inertia acting on the drive shaft (2) can be increased by at least one mass body (15) that is operatively connected with the drive shaft (2).

A seat recliner assembly having a fixed gear plate having a gear portion formed therein. The gear portion is disposed about a first slot that includes a first raised collar. A movable plate having a gear portion formed therein and disposed about a second slot also includes a second raised collar. The gear portion of the movable plate is in operating engagement with the gear portion of the fixed plate and defines an annular race between an outer surface of the first raised collar and an inner surface of the second raised collar. A bearing member is disposed concentric to the inner surface of the second raised collar. First and second wedge members are disposed in the annular race and engage the bearing member. Each of the wedge members includes first and second contact features. A spring member engaging each of the wedge members biases the wedge members apart. A hub member is engaged with a drive shaft and projects through the first slot. A drive plate juxtaposed in relation to the movable plate is adapted to engage the hub member. The drive plate includes first and second engagement features to engage the first and second contact features of the first and second wedge members. Rotary motion of the drive plate causes engagement of the first engagement feature with the first contact feature followed by engagement of the second engagement feature with the second feature.