Abstract: A seat body is assembled with a seat chassis device that has a seat chassis mounted on the seat body. The seat body has an accommodating space and guiding troughs each having a guiding opening. The accommodating space includes a propping portion to be resiliently flattened. The seat chassis device has a base connected thereto and is formed with sliding wedge portions to slide into the guiding troughs from the guiding openings. When the seat chassis slides to a predetermined position, the propping portion springs up and abuts against the seat chassis. A spring between the base and the seat chassis is upward pushed by a resilience-adjusting unit and has its upper end received in a dome raised from the seat chassis and received in a hollow portion of the seat body.

Abstract: An apparatus for adjusting the inclination of a chair back is disposed on the chassis at the bottom of a cushion and pivotally coupled to the middle of a base at the upper end of chair legs. A control rod has its middle predetermined position pivotally coupled to the base. A positioning plate has a bolt at its top surface and is disposed at the rear end of the base. A resilient component is pivotally coupled such that one end of the resilient component is hooked into an end of the control rod, and the other end of the resilient component being hooked into the bolt at the top surface of the positioning plate. When the control rod is turned to swing its end, the resilient component rotates, so that one of the resilient legs of the resilient component produces an elastic push onto the positioning plate. Thus, the positioning plate contracts and moves to embed into or withdraw from a latch groove disposed at the bottom rear side of the chassis.