Height-Adjusting Assembly for Office Chair Backrest

Abstract

A height-adjusting assembly for an office chair backrest includes a supporting unit mounted with a vertically movable backrest. The supporting unit and the backrest have correspondingly an engaging element and a series of positioning teeth, respectively, to be coupled mutually. Upper and lower ends of the series of positioning teeth have a retracting portion and an expanding portion for retracting and expanding the engaging element, respectively. When the backrest slides upward, the engaging element successively engages with one of the positioning teeth so as to position the backrest at a desired height. When the backrest reaches to an upmost position, the engaging element is pressed by the retracting portion and retracts so as to separate from the positioning teeth. Then the backrest reaches a bottommost position thereof has the engaging element expanded by the expanding portion, thereby allowing the engaging element to engage with the positioning teeth again.

Dependencies are inferred from the claim text.