Abstract: An adjustment device for a chair, comprising an oscillating mechanism composed of a first plate, associated with a central gas-operated post for the height adjustment of a seat. A second plate is articulated to the first plate so that it can oscillate, by means of a pair of first pivots and is fixed to a backrest. A linkage is articulated to the first plate, by means of a second pivot, and is in turn articulated, by a third pivot, to a third plate, with which the seat can be associated. The third plate is articulated to the second plate. Elements are associated with the linkage for connection to at least one slat or leaf spring, which is arranged on a plane that is substantially parallel to the plane of the seat and is adapted to elastically contrast the inclination of the second plate with respect to the first plate.

Abstract: An adjustment device for a chair, comprising an oscillating mechanism composed of a first plate, associated with a central gas-operated post for height adjustment of a seat, to which a second plate, fixed to a backrest, is articulated so that it can oscillate by a first pivot. A third plate is articulated and interposed, respectively by a second pivot and a third pivot, between the first plate and the second plate, and can be associated with the seat. The first plate has elements for connection to at least one slat or leaf spring which is adapted to elastically contrast the inclination of the second plate with respect to the first plate.

Abstract: A chair provided with a plate, to which a seat is freely articulated above, by way of at least one first linkage and a second pair of linkages in the rear and front regions, a backrest being articulated laterally and freely to said seat. The first end of a pair of cams is pivoted to the plate at the rear, and the second end is pivoted to the backrest.

Abstract: Adjustment device for a chair which is provided with a rocking mechanism composed of a first plate, fixed to a central gas-operated post for the height adjustment of a seat and to which a second plate is articulated, about a first axis that is transverse thereto and so that it can rock, the second plate being fixed to a seat or being integral with a seat and interacting with elements which are adapted to contrast the rocking of a backrest. A first cable is slideably associated with the first plate and is adapted to activate a lever which is articulated internally to the first plate at a different second axis and is adapted to activate the height adjustment of the seat. A second cable is further slideably associated with the first plate and is adapted to activate a mechanism which allows or prevents the rocking of the second plate.

Abstract: A device for adjusting the position of an armrest of a chair, which comprises a clamp, stably associated with the chair, which interacts selectively with a vertical position selector, associated with a box-like body which constitutes the armrest.

Abstract: A chair provided with a plate, to which a seat is freely articulated above, by way of at least one first linkage and a second pair of linkages in the rear and front regions, a backrest being articulated laterally and freely to said seat. The first end of a pair of cams is pivoted to the plate at the rear, and the second end is pivoted to the backrest. The pair of cams has arc-like guiding means for the sliding of at least one seventh pivot which is integral with and protrudes from the backrest. The first linkage, the second pair of linkages and the pair of cams are adapted to force the forward and downward movement of the seat with respect to a backward inclination that can be imparted to the backrest.

Abstract: Adjustment device (1) for a chair which is provided with a rocking mechanism composed of a first plate (2), which is fixed to a central gas-operated post (7) for the height adjustment of a seat and to which a second plate (10) is articulated, about a first axis (9) that is transverse thereto and so that it can rock, the second plate being fixed to a seat or being integral with a seat and interacting with means (8a, 8b) which are adapted to contrast the rocking of a backrest. A first cable (12) is slideably associated with the first plate (2) and is adapted to activate a lever (13) which is articulated internally to the first plate (2) at a different second axis (14) and is adapted to activate the height adjustment of the seat. A second cable (20) is further slideably associated with the first plate (2) and is adapted to activate a mechanism (21) which allows or prevents the rocking of the second plate (10).