| 摘要 |
The invention relates to a back support adjustment device (1) for chairs, including a pillar (2) upwardly directed from the seat or its substructure for carrying a back support (3), this pillar comprising at least two hollow sections (4, 5). The latter are positionally fixable to each other at a desired height for the back support by a tongue (6) formed in, and integral with, a wall of the outer hollow section (5) at a face (7) thereof, the tongue thus being enabled, with the aid of a force applied to it, to lock the inner section (4) to the outer (5) using friction and without making press marks on the face of the hollow section, against which compressive force is applied. |
