Abstract: A chair gas lift allowing easy disassembly is revealed. A gas lift is disposed between a seat cushion and a chair base of a chair. By extension or retraction of a piston rod of the gas lift, the seat cushion height is adjusted. At least one polygonal ring assembly is arranged around a circumference of the gas lift. Due to the polygonal ring assembly being mounted in an opening of a wrench, a force is applied to the wrench to remove the gas lift from the seat cushion easily.

Abstract: A backrest elevation adjustment assembly is provided, which is mainly composed of an L-shape member, a sliding member, and a multi-step positioning member. A seat supporting board is attached to the horizontal section of the L-shape member and the sliding member, which is attached to a backrest supporting board, is installed on the vertical section of the L-shape member, surrounding the multi-step positioning member embedded in the vertical section of the L-shape member. The sliding member could be slid up and down along the vertical section of the L-shape member and fixed at a number of pre-determined positions provided by the multi-step positioning member. With the elevation adjustment assembly, a chair's backrest could be adjusted to suit a sitter's specific posture so as to achieve comfortable seating.

Abstract: A position structure for a level-adjustable armrest which comprises a driving member, a sliding member and a spring, and those three members are all mounted in an adjusting tube. When the user adjusts the height of the armrest, it will pull the sliding member so as to push the protruded portion from the pressing surface to the surface of the protruded block, so that the engaging member will be rotated limitedly, and the protruded block will be removed from the adjusting groove completely. Thereby the driving member will not be engaged with the engaging member and the semicircle member, and the driving member and the armrest sheath will be removed to the adjusting tube accordingly so as to adjust the height of the armrest.

Abstract: A depth-adjustable device for a chair comprises a rail rack, the railway is formed with a V-shaped concave, and the supporting board is slideably disposed in the railway by four clipping blocks, and in the lower part of each clipping block is formed a V-shaped convex. The inclined concave cooperates with the inclined convex to allow the adjustment device operate firmly. The V-shaped convex of the clipping blocks moveably abuts against the V-shaped concave in the bottom of the respective railways of the rail base, so that the gravity will be focused on the center and the supporting board and the rail base will slide relative to each other but will not wobble and impact each other, thus reducing the operation noise effectively.

Abstract: A backrest elevation adjustment assembly is provided, which is mainly composed of an L-shape member, a sliding member, and a multi-step positioning member. A seat supporting board is attached to the horizontal section of the L-shape member and the sliding member, which is attached to a backrest supporting board, is installed on the vertical section of the L-shape member, surrounding the multi-step positioning member embedded in the vertical section of the L-shape member. The sliding member could be slid up and down along the vertical section of the L-shape member and fixed at a number of pre-determined positions provided by the multi-step positioning member. With the elevation adjustment assembly, a chair's backrest could be adjusted to suit a sitter's specific posture so as to achieve comfortable seating.

Abstract: A structure connection of motion chair is disclosed for connecting a chairback to a chair base. The structure connection of motion chair consists of a pair of first supporting members and a pair of second supporting members respectively installed on both sides of the chairback, and a pair of supporting plates respectively installed on both sides of the chair base. The second supporting members are respectively located below the first supporting members, and the supporting plates are respectively corresponding to the first supporting members and the second supporting members, wherein the supporting plates are used for engaging with the first and second supporting members respectively, whereby the chairback and the chair base are connected together.

Abstract: An office chair includes three connecting element fixedly to a bottom of the seat for the back, the left armrest, and the right armrest to be detachably fitted to respectively; each of the back and the armrests has a support plate having several locating holes; the connecting elements allow respective support plates to be slid on; the support plates can't move up to separate from the connecting elements after having been slid onto the latter. Each of the connecting elements has a spring-loaded locating pin fitted thereto, which can be made to engage one of the locating holes of respective support plates to securely fix the support plates to the seat; thus, the back and the armrests can be adjusted in position, and can be detached from the seat for the chair to occupy less space in packing.

Abstract: A cloth for the seat of an office chair has a middle layer made of polyester. The middle layer is sandwiched between a bottom and a top layers also made of polyester, and has fibers arranged for spaces to form among the fibers, and between the bottom and the top layers; the top layer has meshes, and the distance from the bottom layer to the top layer can be as long as 5 millimeters such that the cloth for the seat is resilient. The bottom, middle and top layers are formed integrally and dyed desired colors under high temperature. And, the cloth for the seat has satisfactory ventilation because air can flow in and out off same through the meshes of the top layer and the spaces among the fibers of the middle layer.