Abstract: A chair backrest comprises a closed loop frame, a net, a frame cover, and the subsidiary supporting-arms. The frame includes a protruding loop edge, defining a global frame-net interface with frame fixing holes therein. A loop-like net fixing piece is used for nailing the border of the net onto the frame-net interface. The subsidiary supporting-arms consists of a pair of branching poles; the ends of the branching poles are connected to a common base with the upper portion of the poles fixed to the frame by frame-arm fixing devices and frame-arm fixing pieces. A back reinforcement board traversing between the right side and the left side of the frame can be added to the rear side of the frame to further support the frame against forces applied.

Abstract: A seat for a chair includes a loop-like main frame having an upper flange wall and a lower flange wall. The main frame further includes an inner engaging edge extending radially inward and an outer flange extending radially outward. An upper perimeter face of the outer flange and an outer perimeter of the upper flange wall together define an upper coupling section to which a coupling frame is securely mounted. A rigid bottom board is securely mounted to the inner engaging edge. A mesh is mounted on top of the upper flange wall and fixed to the main frame. The mesh includes a perimeter covering the upper coupling section, with a space being delimited between the mesh and the bottom board. The seat has a reliable structure and provides cool, comfort sitting by provision of the space between the mesh and the bottom board.

Abstract: A height-adjustable armrest for a chair includes a body, a coupling seat, and an adjusting device mounted to the coupling seat. The body includes an arm support section for supporting an arm of a user. The body further includes a tubular section having a vertical slot with a plurality of vertically spaced positioning grooves. The coupling seat includes a longitudinal hole so as to be mounted around the tubular section of the body. The adjusting device includes a push button and a positioning member having a positioning section that is releasably and selectively engaged in one of the positioning grooves. The positioning section of the positioning member is disengaged from the positioning grooves when the push button is pushed, allowing adjustment of a height of the body.

Abstract: A backrest includes an endless main frame having a groove defined in a side thereof and extending along an entire length thereof. The groove is delimited by a bottom wall and an inner peripheral wall having an endless end face. A mesh is fixed to the endless end face of the inner peripheral wall delimiting the groove. A decorative frame is mounted to the side of the endless main frame and covers the groove and the endless end face of the main frame. A covering member covers the decorative frame. An aesthetically pleasing appearance is thus provided. Further, the decoration effect can be improved by the decorative frame and the covering member.