Patent ID: 9144315
Filing Date: 2015-09-29
Classification: A47C

Abstract:
1. An adjustment device of a chair having: a foot ring having a first positioning unit being curved, mounted in the mounting tube and having an inner threaded portion formed on a side of the first positioning unit; a second positioning unit being curved, mounted in the mounting tube, facing towards the first positioning unit, and having an inner threaded portion formed on a side of the second positioning unit, wherein the side of the second positioning unit faces towards the first positioning unit, the inner threaded portions of the first positioning unit and the second positioning unit are connected with each other to form a tapered and fully threaded structure, and the block abuts one of the first positioning unit and the second positioning unit; and a tightening collar engaging with the threaded structure formed by the inner threaded portions of the first positioning unit and the second positioning unit, and having