Abstract: A stackable chair has a backrest mounted on back supports by resilient mount units for tilting between an upright position and a tilted-back position. Each mount unit includes a rigid coupling member having a lower portion received within an upper end portion of the respective back support and pivotally joined to the respective back support and having an upper portion received within and affixed to a socket in the backrest. A compression spring received within the upper end portion of the back support and engaged between the lower portion of the coupling member and a front wall of the respective back support biases the backrest to the upright position. An armrest is slidably supported on an armrest support for simultaneous and controlled pivotal movement about a substantially vertical pivot axis of a rearward part of the armrest relative to a forward part of the armrest and translatory movement in a plane perpendicular to the pivot axis. Movements of the armrests permit dense stacking of the chairs.

Abstract: A chair includes: a hollow frame including, on each lateral side of the chair, a front, a back, a bottom, a front bend arranged between the front and the bottom, and a back bend arranged between the back and the bottom; a seat attached to the front of the frame; a seat back attached to the back of the frame; at least one front stiffener insert arranged inside the frame at the front bend and extending along a partial length of the front and the bottom; and at least one back stiffener insert arranged inside the frame at the back bend and extending along a partial length of the back and the bottom. The front stiffener inserts and the back stiffener inserts stiffen the frame relative to a frame without such inserts. The seat back and the seat may be movable independently of each other relative to the bottom of the frame.

Abstract: A stackable chair has a frame with a tubular crosspiece, to each end of which a monolithic casting having legs and a backrest support—and, optionally, an armrest—is attached by means of an integral connecting boss received within the crosspiece and held in place by a connector pin. The backrest supports receive a backrest that pivots between an upright position, to which it is biased by a spring mechanism, and a rearwardly tilted position. The range of tilting motion is limited by a stop pin on the backrest and a stop groove in the backrest support. A seat is mounted on the crosspiece, either in a fixed position or for tilting to an upright position. Chairs with tilting seats include seat supports having diametrically opposite slots that receive projecting portions of the connecting pins. The connector pins slidably engage the sides of the slots to hold the seat supports in place on the crosspiece axially.

Abstract: A chair has a pair of spaced-apart back support mounting members, a lower back support adapted to support the lower portion of the back of a person seated on the chair and mounted on the back support mounting members for pivotal movement about a pivot axis located at substantially the vertical centerline of the lower back support, and an upper back support adapted to support the upper portion of the back of a person seated on the chair and mounted on the back support mounting members for pivotal movement about a pivot axis located at substantially the vertical centerline of the upper back support.

Abstract: Adjustable seating has a frame, a seat bottom mounted on the frame so as to slide forwardly and rearwardly, and a seat back mounted on the frame so as to slide upwardly and downwardly and also to tilt rearwardly from a resiliently restrained upright position. A lumbar back is mounted on the frame between the seat bottom and seat back so as to move generally in coordination with movements of the seat bottom and seat back. The lumbar back provides good support for the lumbar portion of the body of a person seated in the seating in all postures and all positions of the seat bottom and seat back.

Abstract: Adjustable seating comprises a frame having a seat-supporting portion and a back-supporting portion, a seat bottom mounted on the seat-supporting portion for movement between rearward and forward positions and a seat back mounted on the back-supporting portion by at least one resilient articulating linkage for tilting movement independently of the position of the seat bottom. The seat back is connected to the seat bottom by a flexible but non-extensible coupling member and is slidable up and down on an upper linkage member of the articulating mechanism so that when the seat bottom moves forwardly or backwardly, the seat back moves downwardly or upwardly, respectively, in correspondence with the movements of the seat bottom. A configuration control spring biases the seat back/bottom to an upward/rearward configuration.