Patent 7246859 was granted and assigned to Okamura on July, 2007 by the United States Patent and Trademark Office.
A chair has a backrest and a pair of armrests. A pair of support struts for supporting the backrest is connected to a shaft of a base under a seat. The armrest is supported by an arm post. An operating lever is mounted on the upper front end of the arm post. When the backrest is tilted, it is held at a desired angle by pressing up the operating lever.