Abstract: A recliner adjuster for adjusting an inclination of a seat back with respect to a seat cushion includes a cam rotatably mounted between first and second brackets that are respectively fixed to the seat cushion and the seat back, a pair of lock plates interposed between the first and second brackets so as to move radially outwardly or inwardly with rotation of the cam, and a pair of auxiliary lock plates interposed between the first and second brackets. Each lock plate has an engaging portion having teeth formed on an outer edge thereof, and each auxiliary lock plate has teeth formed on an outer edge thereof and is slidable in a direction generally perpendicular to the direction in which the lock plates slide. When a large load has been applied to the seat back due to, for example, a vehicle collision, the teeth of the lock plates and those of the auxiliary lock plates are brought into engagement with internal teeth of the second bracket.

Abstract: A recliner adjuster for adjusting an inclination of a seat back with respect to a seat cushion includes a cam rotatably mounted between first and second brackets that are respectively fixed to the seat cushion and the seat back, and a lock plate interposed between the first and second brackets so as to move radially outwardly or inwardly with rotation of the cam. The lock plate has an engaging portion having teeth formed on an outer edge thereof and respective side edges. The lock plate also has first and second shoulder portions formed on respective sides of the engaging portion. The first bracket has first and second guide members that define a guide groove therebetween in which the engaging portion of the lock plate is slidably received. The second bracket has internal teeth that are brought into engagement with the teeth of the engaging portion of the lock plate when the lock plate moves radially outwardly.