Abstract: A chair base is revealed. A round bulge is formed on a center of a bottom surface of a bottom plate and a limit portion is gradually flattened from the round bulge toward a periphery of the bottom plate. A base body is disposed on a top surface of the bottom plate while a cover is used for covering the base body therein and enclosing the periphery of the bottom plate. Thereby the bottom plate, the base body, and the cover are connected and fixed by one another. While in use, users rock the chair by the round bulge on the bottom plate in response to their shifts in center of gravity. A rock angle of the chair is limited by the limit portion. Thereby the users will not tip the chair over while rocking the chair violently and safety in use is ensured.

Abstract: A chair back and seat assembly is revealed. The assembly includes a seat base having an assembly recess with two long locking hole on two side walls, and a back support which includes a connection portion on one end and a driving member at the connection portion and connected with locking bars of the connection portion. During assembly, a pull plate of the driving member is pushed by a recess opening of the assembly recess when the connection portion of the back support is mounted into the recess opening of the assembly recess. Thus the driving member is moved backward and driving the two pre-retracted locking bars to be protruding and further locked by the locking holes of the assembly recess. Thereby the assembly is completed easily and conveniently. The design also prevents the seat base and the back support from unexpected loosening while seated.

Abstract: A reclining seatback support device which mainly includes at least one seatback support and a seatback body is revealed. The seatback body and an upper end of the seatback support are provided with pivot bracket portions pivotally connected to each other while a lower part of the seatback body and the seatback support are connected by a swing arm. When a user is sitting and lying down on the back, the seatback body is rotated around the pivot axis where the seatback body is pivotally connected to the upper end of the seatback support and then reclined at a certain angle. By elastic segments of the seatback body and the swing arm between the lower part of the seatback body and the seatback support for pulling and limiting the seatback body, the user can lean on the seatback body comfortably and safely.

Abstract: The present invention discloses a structure for rapidly assembling a chair back and a chair seat. It comprises a chair seat underframe having a first engaging portion and an assembling channel and a chair back stand having a second engaging portion and an assembling block for correspondingly engaging with the assembling channel. The assembling channel has two protrusions at two lateral walls and the assembling block has two engaging grooves at two laterals for positioning and engaging with the two protrusions. The assembling channel of the chair seat underframe has an engaging hole, and a telescopic pin disposed at a bottom of the assembling block is positioned and engaged with the engaging hole. The assembling channel of the chair seat underframe and the assembling block of the chair back stand are further screwed together by a screwing member.

Abstract: A twistable chair backrest frame is disclosed herein. It has a hollow section and two opposite elastic supporting ribs at a right side and a left side of the hollow section.

Abstract: A chair seat includes a lower loop-shaped member, an auxiliary mesh, a loop-shaped pad part, and an upper mesh; the lower loop-shaped member encircles a first space; the auxiliary mesh is positioned over the first space and the lower loop-shaped member, and securely connected to the lower loop-shaped member at an edge; the loop-shaped pad part encircles a second space, and is secured over the lower loop-shaped member with the second space being right above the first space; the upper mesh is positioned over the second space and the loop-shaped pad part, and securely joined to a lower side of the lower loop-shaped member at an edge; the seat is positioned on top of and joined to a loop-shaped portion of a main unit of a chair at the lower loop-shaped member thereof so that the auxiliary mesh will help the upper mesh bear the sitter's body weight.

Abstract: A chair pillow includes a secured member fixed on a top of a back of a chair, an intermediate member, and a pillow body; the intermediate member is pivoted to the secured member at a first end thereof such that it is normally held in position by the secured member, and can be forced to change orientation relative to the secured member; the pillow body is pivoted to a second end of the intermediate member at a rearwards projecting portion thereof such that it is normally held in position by the intermediate member, and can be forced to change orientation relative to the intermediate member; therefore, the pillow body can be adjusted in position as well as in the orientation relative to the back.

Abstract: A mesh chair back includes a loop-shaped frame, an elastic mesh part, a waist support unit, and a smooth separating plate; the loop-shaped frame has left and right upright portions; the elastic mesh part is positioned over and secured on the loop-shaped frame; the waist support unit is arranged behind the elastic mesh part, and connected to the left and the right upright portions of the loop-shaped frame at two ends in an up and down displaceable manner; the smooth separating plate is positioned between the mesh part and the waist support unit for preventing the waist support unit from rubbing and causing wear to the mesh part while the waist support unit is being adjusted in height; the waist support unit props the separating plate and the mesh part forwards such that the separating plate and the mesh part each has a forwards protruding portion.