Patent ID: 6382724
Filing Date: 2002-05-07
Classification: A47C

Abstract:
Chair with a tilting seat, comprising:a base structure bearing a transverse tilting axis, a seat support structure, titlably mounted about said transverse tilting axis, elastic means capable of opposing the seat tilting motion, and adjustment means for varying the force opposing said elastic means, wherein the elastic means comprises a torsion bar which connects the seat support structure to the base structure in a tilting manner about said transverse tilting axis, the torsion bar having at least a first portion rotatably connected to the seat support structure and at least a second portion connected to the base structure through the adjustment means, wherein the adjustment means are arranged to vary the angular position of the second portion of the torsion spring about the transverse tilting axis, wherein the adjustment means comprise a lever fixed to the second portion of the torsion bar, a manually operable rotatable knob and a gearing-down device defining a correlation between the angular position of the knob and the angular position of the lever, and wherein the gearing-down device comprises a wedge which can slide in a longitudinal direction having an inclined surface which acts together with one end of the lever, the wedge being associated with a screw and nut mechanism capable of varying the axial position of the wedge in relation to the angular position of the operating knob.