Patent ID: 7828389

Claim:
An armrest device in a chair, comprising: an armrest support tube extending upright from a seat; a tubular armrest support rod that slides up and down in the armrest support tube to support an armrest; an intermediate tube surrounding the armrest support rod in the armrest support tube and having a plurality of engagement portions; an operating lever having a middle portion which is pivotally mounted to an upper end of the armrest support rod, the operating lever comprising an operating portion that projects forwards of the armrest support rod; and a turning lever that fits in said armrest support rod and has lobes in a middle contacting an inner circumferential surface of the armrest support rod and a hole at a lower end, the turning lever pivoting about a center of curvature of the lobes, one of a rear end of said operating lever and an upper end of the turning lever having an engagement groove which engages with the other, a pin through the hole at the lower end of the turning lever passing through a hole of the armrest support rod, the pin selectively engaging in any one of the plurality of engagement portions, the turning lever comprising an urging portion urging the pin to engage with any one of the engagement portions, wherein a shaft is transversely projected in a middle of the operating lever and engages in a groove which opens upwards at an upper end of the armrest support rod, a lower surface of a closing member that closes an upper opening of the armrest support rod contacting the upper surface of the middle portion of the operating lever so that said shaft is prevented from coming off the groove.