Patent attributes
A backrest height adjusting device includes a fixing seat fixed in relation to a chair seat and having at least one fixing post. A backrest includes at least one coupling sleeve coupled with the at least one fixing post. At least one gear is rotatably mounted to the fixing block fixed on the backrest and is coupled with a plurality of positioning grooves on the at least one fixing post. An elastic element biases a movable block to move relative to the fixing block in a vertical direction and biases the movable block to mesh with the at least one gear to retain the backrest in a selected height relative to the fixing seat. The movable block is actuatable to disengage from the plurality of teeth of the at least one gear to thereby permit the backrest to move in the vertical direction relative to the fixing seat.
