Abstract: A chair and a method for fabricating the chair are provided. Therein, a butterfly mechanism has projecting portions for engaging with receiving recesses formed on a seat frame of the chair, and then the combined butterfly mechanism and seat frame can be fixed by screw members. A tubular portion at the butterfly mechanism is then mounted around a gas lift of a base portion of the chair. Then forward-extending projecting portions formed on a back frame of the chair are engaged with receiving recesses formed correspondingly on the butterfly mechanism, and the back frame and the butterfly mechanism are fixed by using screw members. An inward-extending connecting portion formed at a lower part of each of two armrest supports is inserted into a through hole on the seat frame, and the two components are fixed by using screw members.

Abstract: An adjustable lumbar support assembly for a chair includes a base, a lumbar support, and an angle adjustment assembly. The base is formed at a lower end of the backrest of the chair. Bar sections bilaterally formed at a lower end of the lumbar support are positioned across the base. The angle adjustment assembly is connected with one bar section of the lumbar support and the base. To tilt the lumbar support forward or backward, a pulling rod is pulled backward to bring the lumbar support into a free state where projections on corresponding surfaces of a positioning element and a moving element mounted around the pulling rod are pressed against each other to allow manual adjustment of the lumbar support for optimal support. When the pulling rod is pushed back, the lumbar support enters a locked state where the positioning element and the moving element are in projection-recess engagement.

Abstract: A headrest adjusting structure for a seat comprises a base and a rotating support. The base is formed with a groove for receiving a supporting portion of the rotating support which has outwardly cavities. The base has outwardly accommodating spaces which is formed with an aperture for receiving a ball and resilient element on two sides. Each ball has an end engageable with the corresponding recess on the positioning disk mounted in the rotating support. A threaded fastener can penetrate the pressing plates fitted in the accommodating spaces of the base, the base and the supporting portion of the rotating support, and be screwed into a nut to hold together. A cap is mounted on each accommodating space of the base. A headrest which is combined at the headrest adjusting assembly installed on a seat can be adjusted to a preferred position by manually pulling the rotating support easily.