| 摘要 |
The present invention concerns an adjustable oleopneumatic support, particularly for the height adjustment of the seat of office chairs with central columns. The oleopneumatic element includes a hollow cylindrical body (2) with a packing member (12) realizing an upper and a lower cavity (22-23, 11), the respective lower end being rigidly linked to the base of the chair, and a coaxial hollow stem (15), the head of which is rigidly linked to the seat of same chair, said hollow coaxial stem (15) being rigidly connected to a piston (20) which defines inside said upper cavity two chambers, an upper and a lower chamber respectively (22, 23) both containing fluid; said hollow coaxial stem (15) being provided inside with valvular coaxial actuation means (33-43) controlling a passage for a hydraulic fluid (40, 41) the respective outlets being placed above and below the piston (20) respectively; said lower cavity (11) being able to contain compressed gas. |
