Abstract: A chair that can transition from an upright position to a reclined position includes a base to rest on a floor, a post upstanding from the base, a chassis affixed to a top of the post and having left and right extensions, armrests extending upward from the left and right extensions. A seat is made up of a seat pan and a seat upper support frame, which are positioned under and above the chassis respectively and has a hole through which the post extends. A backrest has a lower end pivotally joined to the seat and a pivotal connection to each of the armrests, so rearward pressure on an upper area of the backrest causes pivoting of the backrest at the armrests and at the seat, pushing the seat forward to a reclined position in a synchronous motion.

Abstract: A double shell seat includes a base for resting on a floor, an outer shell supported by the base, and an inner shell movably supported within the outer shell. The inner shell has a seat support, a backrest support, and a hinge between the seat support and the backrest support. The inner shell is movable with respect to the outer shell from an upright condition in which the seat support has a position toward the rear of the outer shell, the backrest support has a position that is relatively vertical, and the hinge is at a first angle, to a reclined condition in which the seat support is forward of its position in the upright condition, the backrest support is less vertical than its position in the upright condition, and the hinge is open at a greater angle than the first angle. The seat is preferably free of coil springs.

Abstract: A double shell seat includes a base for resting on a floor, an outer shell supported by the base, and an inner shell movably supported within the outer shell. The inner shell has a seat support, a backrest support, and a hinge between the seat support and the backrest support. The inner shell is movable with respect to the outer shell from an upright condition in which the seat support has a position toward the rear of the outer shell, the backrest support has a position that is relatively vertical, and the hinge is at a first angle, to a reclined condition in which the seat support is forward of its position in the upright condition, the backrest support is less vertical than its position in the upright condition, and the hinge is open at a greater angle than the first angle. The seat is preferably free of coil springs.

Abstract: A chair that can transition from an upright position to a reclined position includes a base to rest on a floor, a post upstanding from the base, a chassis affixed to a top of the post and having left and right extensions, armrests extending upward from the left and right extensions. A seat is made up of a seat pan and a seat upper support frame, which are positioned under and above the chassis respectively and has a hole through which the post extends. A backrest has a lower end pivotally joined to the seat and a pivotal connection to each of the armrests, so rearward pressure on an upper area of the backrest causes pivoting of the backrest at the armrests and at the seat, pushing the seat forward to a reclined position in a synchronous motion.

Abstract: This disclosure describes a chair having a base frame, a seat support, and a backrest support. The seat support is connected to the backrest support. The backrest support is rotatably connected to a rear part of the base frame such that a pivot axis is defined about which the backrest support is pivotable. The seat support is connected to a front part of the base frame by at least one four-joint coupling mechanism, whereby the seat support is moved on a defined movement path in the chair longitudinal direction during a pivoting movement of the backrest support.

Abstract: A chair of the type having a seat and a separate seat back including a chair frame with a rear segment. The seat back is movably secured to the frame by a mounting mechanism whereby the seat back is capable of pivoting about at least two axes of rotation. The seat may also be connected to a fixed seat support by at least one mounting mechanism, allowing the seat to be pivoted about at least one axis of rotation.

Abstract: An office chair in which a backrest and seat are articulated together and the resulting assembly pivotally suspended from the rear end of the side arms which form a pivot point positioned at or near the center of gravity of the chair when occupied. The pivot point is fixed in space by an underlying support system. The lower end of the arm rest is affixed to the rear transverse support arm of a support frame which is, in turn, mounted on the upper end of a vertical support column. The front end of the set member is slidably mounted on a forward cross arm of the support frame through a hexagonally-shaped sliding/locking member in such manner that the back rest and seat may be selectively locked in position or released to adjustably recline (backrest) and slide (seat).