摘要 |
The invention refers to a device to height adjustment and locking of a chair seat (2). Around a main vertical column (1) an adjustable tubular body is set up along the column (7), which supports the seat. Between the column (1) and the tubular body (7) a spiral spring is set up (11), which aims to raise the tubular body. The exerted momentum of the seat causes, however, frictional forces between the tubular body and the column, which locks the body to the column. By slightly lifting the seat, the friction ceases, so that the spring raises the tubular body and thereby the seat.<IMAGE> |