Patent ID: 6935689

Claim:
A chair comprising a first axis that extends right and left and that connects a seat and a supporting body arranged under the seat in a rotatable manner at a front end portion of the seat, a second axis that connects the seat and a backrest in a rotatable manner at a rear side to the first axis and a third axis that connects the backrest and the supporting body in a rotatable manner, wherein the seat and the backrest make a rocking movement between an upright posture and a rearward tilted posture with synchronizing of the seat and the backrest by adopting a sliding engagement structure to a supporting portion of the first axis, the chair further comprising a restraining member to restrain a sliding range of the first axis by directly acting on the first axis, wherein the restraining member is capable of moving or transforming between a restraining position where the sliding range of the first axis is restrained and a recessed position where the sliding range of the first axis is not restrained, and wherein the restraining position can be set at a plurality of different positions and the restraining member restrains the sliding range of the first axis at any one of the different positions.