| 摘要 |
PCT No. PCT/EP97/04800 Sec. 371 Date Mar. 2, 1999 Sec. 102(e) Date Mar. 2, 1999 PCT Filed Sep. 4, 1997 PCT Pub. No. WO98/09553 PCT Pub. Date Mar. 12, 1998A device for adjusting the height of a back-rest of a seat back portion, in particular in office chairs, comprising a guide element rigid with a support plate of a seating portion, a slide for supporting the back-rest, the slide being engagable with the guide element and slidable along it, and means which are elastically selectively engageable with a toothed portion to ensure the stability of the position of the slide relative to said guide. The elastic means are able to slide freely along the passive flanks of teeth of a toothed portion during the raising of the back rest, and are locked by the active flanks after each passage over a tooth. |
