Patent ID: 9700139
Date: 2017-07-11
CPC Classifications: A47C

Claim:
1. An armrest structure for a chair, comprising: a connecting seat, having a sleeve, a bottom of the sleeve being formed with a cavity; a height adjustment rod disposed in the sleeve, being a U-shaped body having two parallel symmetric boards, each of the two boards being formed with semicircular recesses, a receiving room being formed between the two boards, and bottoms of the two boards being formed with an insert received in the cavity; an elevation rod disposed in the sleeve, being out of and parallel to the height adjustment rod, a first end of the elevation rod being formed with a projection received in the receiving room, the projection having an inserting hole, a second end of the elevation rod being formed with a connecting seat with a cylinder and a spring secured around the cylinder; an armrest set having a tube and an armrest connected atop the tube, the tube being received in the sleeve and sheathing the height adjustment rod and the elevation rod, a top of the tube being formed with a channel communicating with an inside of the tube, a trigger being received in the channel and connecting with the connecting seat, and the spring pushing a top end of the sleeve; and a fixing bar being inserted into the inserting hole and embedded into one of the recesses; wherein a top of the tube is formed with a protruding block engaging with a bottom of the armrest, and the armrest set further comprises: a base being formed with two parallel guide boards and an opening for receiving the protruding block, and one side of each guide board is formed with a wavy surface; a rotation seat disposed in the base, having a passing hole corresponding to the opening so that the protruding block is received in the passing hole, an end of the rotation seat being formed with two troughs in a row, each trough receiving a guide block, and each of two opposite inner ends of the rotation seat being formed with a guide surface; a steering seat being disposed in the rotation seat, a center of the rotation seat being provided with a lock hole corresponding to the passing hole and the opening, the lock hole, the passing hole and the opening being passed by a screw which screws with the protruding block, each of two opposite ends of the rotation seat being formed with a notch for receiving a steering block, and the steering blocks corresponding to and abutting against the guide surfaces; and a cover assembled with the base.