Patent ID: 7021715

Claim:
A recliner adjuster for a seat for adjusting an inclination of a seat back with respect to a seat cushion, comprising: a first bracket to be fixed to the seat cushion; a second bracket to be fixed to the seat back so as to confront the first bracket; a cam rotatably mounted between the first and second brackets; 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, each lock plate having an engaging portion that has teeth formed on an outer edge thereof and also having first and second shoulder portions formed on respective sides of the engaging portion; the first bracket having a plurality of guide members that define therebetween a pair of first guide grooves and a pair of second guide grooves, the engaging portion of each lock plate being slidably received in one of the first guide grooves; the second bracket having a recess defined therein in which the plurality of guide members are received and also having internal teeth that are brought into engagement with the teeth of the engaging portion of each lock plate when the lock plate moves radially outwardly with the engaging portion thereof guided by one of the first guide grooves of the first bracket; and a pair of auxiliary lock plates interposed between the first and second brackets, each auxiliary lock plate having teeth formed on an outer edge thereof and being slidably received in and slidably guided by one of the second guide grooves; wherein when a load applied to the second bracket inclines the lock plates, the lock plates slide the auxiliary lock plates outwardly in said second guide grooves to engage the teeth of the auxiliary lock plates with the internal teeth of the second bracket.