| 摘要 |
A mechanical interconnection between the seat and backrest of a chair (eg. an office chair) increases or decreases the vertical height of the backrest above the upper surface of the seat when the seat is respectively raised or lowered, so as to maintain a prearranged relationship between the seat and the backrest. The ratio of change in backrest height: change in seat height is preferably approximately 2:1; a suitable mechanism comprises a belt and pulley arrangement |
