Abstract: An office chair mechanism provided with a device for adjusting the swivel force includes a fixed part secured to the chair base, movable parts secured to the seating portion and to the back rest (22) of the chair, and an elastic element which opposes the weight of the chair user, a lever having contact surfaces which interact with said fixed part by means of a fulcrum having a movable contact element interposed between the end acting on the elastic element and the other end to which the movable parts are pivoted, and an adjustment element which causes only the movable contact element to move but without modifying the position of the elastic element and of the lever.

Abstract: The invention relates to a seat for a vehicle, in particular for all-terrain vehicles, with at least one seat area extending in the longitudinal direction (X) of the vehicle and in the width-wise direction (Y) of the vehicle for receiving a person, a backrest for supporting the back of the person and a holding device connected in the vertical direction (Z) under the seat area and to the latter for keeping the seat area at a distance from a coupling region for coupling the seat to the vehicle, wherein the holding device has at least one spring device for the movable arrangement at least for a time of at least the seat area with respect to the coupling region in the longitudinal direction (X) of the vehicle and/or in the width-wise direction (Y) of the vehicle.

Abstract: An office chair mechanism provided with a device for adjusting the swivel force includes a fixed part secured to the chair base, movable parts secured to the seating portion and to the back rest (22) of the chair, and an elastic element which opposes the weight of the chair user, a lever having contact surfaces which interact with said fixed part by means of a fulcrum having a movable contact element interposed between the end acting on the elastic element and the other end to which the movable parts are pivoted, and an adjustment element which causes only the movable contact element to move but without modifying the position of the elastic element and of the lever.

Abstract: A seat back assembly (16) for a seat (10), comprising an upper seat back portion (24) for supporting an upper portion of a user's back and a lower seat back portion (22) for supporting a user's pelvis and pelvic region. The lower seat back portion (22) and the upper seat back portion (24) are independently adjustable. The upper seat back portion (24) can be reclined to one of a number of fixed angular positions and it is arranged and configured for dynamic angular movement under a load over a range of positions. The dynamic movement of the upper seat back portion (24) is controlled by a shock absorber (44) having adjustable damping means for providing a required level of tension and rebound in relation to the dynamic back action of the upper seat back portion (24).

Abstract: A work station chair (10) is enabled to shift in response to a person leaning forward in the chair (10) when in a working mode and leaning back in a rest position. The chair includes a seat (18), a backrest (24) and supportive structure. The seat (18) is resiliently supported on the supportive structure (22) and moveably along an arc track (30) which is mounted on the supportive structure and has a radius generated from the ankle of the person sitting on the chair. The backrest (20) is resiliently supported on the seat (18) and moveable along an arc track (64) which is mounted to the seat (18) and has a radius generated from H-point that is a natural pivot point of the torso and thigh lines of the person. The chair (10) provides a combined tilting movement of the person's body about the ankle point and the H-point when the person shifts his or her gravity to reduce adverse static postural loads and forces which are responsible for the fatigue and biomechanical dysfunction.