Adjustment device for a chair with rocking mechanism

An adjustment device for a chair, said adjustment device comprising:

• a rocking mechanism composed of a first plate, which is fixed to a central gas-operated post for the height adjustment of a seat;
• a second plate that is articulated to said first plate, about a first axis that is transverse to said first plate and so that said second plate can rock, said second plate being fixed to a seat or being integral with a seat;
• means that interact with said second plate and that are adapted to contrast the rocking of a backrest;
• a first cable that is slideably associated with said first plate;
• a lever that is adapted to be activated by said first cable and that is articulated internally to said first plate at a second axis, wherein the second axis is different from said first axis, and that is adapted to activate the height adjustment of said seat;
• a second cable being further slideably associated with said first plate;
• and
• a mechanism that is adapted to be activated by said second cable and that allows or prevents the rocking of said second plate,
• wherein said second plate is articulated to said first plate so that said second plate can rock, by virtue of first pivots which lie on said first axis which is transverse and eccentric with respect to said first plate, said first plate interacting with a pair of first springs, said first cable being slideably associated with a side of a front part of said first plate and being adapted to activate said lever, which is articulated inside said first plate at a second axis which is distinct from said first axis and is inclined with respect to the longitudinal axis of said first plate, said lever being L-shaped so as to define a first wing, which is directed toward a first base of said first plate, and a second wing, which is adjacent to and lies above said central gas-operated post, said lever being pivoted, in a connecting region between said first wing and said second wing, to a second pivot arranged at said second axis.

An adjustment device for a chair, said adjustment device comprising:

• a rocking mechanism composed of a first plate which is fixed to a central gas-operated post for the height adjustment of a seat;
• a second plate that is articulated to said first plate, about a first axis that is transverse to said first plate and so that said second plate can rock, said second plate being fixed to a seat or being integral with a seat;
• means that interact with said second plate and that are adapted to contrast the rocking of a backrest;
• a first cable that is slideably associated with said first plate;
• a lever that is adapted to be activated by said first cable and that is articulated internally to said first plate at a second axis, wherein the second axis is different from said first axis, and that is adapted to activate the height adjustment of said seat;
• a second cable being further slideably associated with said first plate;
• and a mechanism that is adapted to be activated by said second cable and that allows or prevents the rocking of said second plate,
• wherein said second cable is slideably associated with a side of a front part of said first plate which lies opposite an entry side for inserting said first cable, said second cable being adapted to activate said mechanism which allows or prevents a rocking of said second plate, said second cable being guided inside said first plate so that a terminal end thereof arranges itself proximate to a bottom of a first cavity which is provided inside and longitudinally to said first plate, on a side thereof which lies opposite the entry side of said first cable.