Office chair has wheeled base, on which support column is mounted, which is made up of rigid lower plate, to which wheels are attached, and upper plate carrying column with springs between two plates
摘要
<p>The office chair has a wheeled base on which a support column is mounted. This is made up of a rigid lower plate (4), to which the wheels are attached, and an upper plate carrying the column with springs (5) between the two plates.</p>
