US Patent 9107504 Reclining loop frame stacking / swivel chair

A chair with a seating surface and a link with two ends connected to the seating surface. A frame with two supporting portions connected to the link and the frame can displace against a bias to allow one of the two supporting portions to move, allowing the seating surface to tilt. A flexible front is attached to a front member on the frame, the flexible front bends when the seating surface tilts. The link rotates when the supporting portions displace. The supporting portions are round and pass through round holes in the link, allowing the supporting portions to rotate within the link when the seating surface tilts. A stop connected to the seating surface and a stop connected to the frame limits the maximum tilt angle of the seating surface.