A chair with an adjustable back depth includes a chassis, a seat plate, a back plate, a hinge seat, a pneumatic rod, a trigger piece, a drive piece, a support seat frame, rocking bars. The hinge seat includes a hinge cavity and a rod channel. The hinge seat is arranged in the accommodating cavity. An inner side of a lower end is hinged to a rear hinge hole of the support plate. A lower hinge plate of the rocking bar is hinged to a front hinge hole of the support plate. A main body of the pneumatic rod is hinged to the bottom hinge cavity. The trigger piece is hinged to the hinge seat and cooperates The drive piece is arranged on the chassis An adjustment device consists of the hinge seat, which has a simple structure, convenience in assembly, realize the adjustment of the depth of the back.

The invention relates to a seating assembly (100) comprising a basic frame (101), a seat unit (102), and a back-support unit (103) wherein the seat unit and the back-support unit have a common pivoting axis (P) with respect to the frame at the level of the hip joint. Hence, based on human body like biomechanics and physiognomy, the seating assembly, particularly for ergonomic chairs or wheelchairs, provides a highly improved seating comfort, even with therapeutic effect.

Embodiments of the present invention provide an improved pivot articulation for a kinematic seat. Certain embodiments provide an elastic pivot that is formed as flexion weaves that connect upper and lower portions of a seat back. The flexion weaves may be inner and outer legs that are curved in configuration or that have bent dimensions.

An adjustment device for a chair with an oscillating mechanism having a first plate, connected to a central gas-operated post for height adjustment of a seat, to which a second plate, fixed to a backrest, is articulated so that the second plate can oscillate by means of a first pivot, wherein a third plate is articulated and interposed, respectively by means of a second pivot and a third pivot, between said first plate and said second plate, and is configured to be connected to said seat, said first plate having means for connection to at least one slat or leaf spring which is adapted to contrast to an inclination of said second plate with respect to said first plate.

A chair with an adjustable back depth includes a chassis, a seat plate, a back plate, a hinge seat, a pneumatic rod, a trigger piece, a drive piece, a support seat frame, rocking bars. The hinge seat includes a hinge cavity and a rod channel. The hinge seat is arranged in the accommodating cavity. An inner side of a lower end is hinged to a rear hinge hole of the support plate. A lower hinge plate of the rocking bar is hinged to a front hinge hole of the support plate. A main body of the pneumatic rod is hinged to the bottom hinge cavity. The trigger piece is hinged to the hinge seat and cooperates The drive piece is arranged on the chassis An adjustment device consists of the hinge seat, which has a simple structure, convenience in assembly, realize the adjustment of the depth of the back.