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: 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.