Abstract: A flexible support device for chair back tilting contains: a supporting frame, a seat mounting, and a base. The supporting frame includes a back portion, two peripheral extensions, two rotatable edges, two first coupling orifices, and two second coupling orifices. The seat mounting includes a first fixing portion, a second fixing portion, two connecting fences, two rotatable locating portions, two defining orifices, two joining elements, two slide orifices, and a drive protrusion. The base includes two locating fringes with two first positioning orifices, two second positioning orifices, a holder connected with a first end of a spring, and a second end of the spring is connected with a flexible sheet. The flexible sheet has two peripheral sections. The base further includes two connection segments, and the two connection segments have two openings. Two connectors are configured to accommodate the flexible sheet and have two pegs.

Abstract: A chair includes a seat, a post, a foot ring, a bushing and a positioning base. The post is connected to the seat. The foot ring has a ring body and a sleeve. The bushing is fastened in the sleeve and has a conic inner surface. The inner surface tapers upward. The inner surface has an inner thread. The positioning base is of a tubular shape and axially fastened onto the post. The positioning base has openings. Each opening is embedded by a braking block. An outer surface of each braking block has an outer thread. The outer surfaces of the braking blocks jointly form a conic shape corresponding to the inner surface of the bushing. The outer thread screws with the inner thread. The bushing presses the braking blocks to move toward the post to fasten the foot ring onto the post when the foot ring is rotated.

Abstract: The seat or backrest includes a meshed fabric; a frame being of an annular shape and attached by the meshed fabric; a frame seat having fixing holes and a groove for receiving the frame; and a base having an annular carrier on a periphery thereof. The carrier is disposed with assembling holes corresponding to the fixing holes and a surrounding wall for isolating an assembling position of the frame seat. The frame presses the meshed fabric to be embedded into the frame seat so that the meshed fabric is fastened on a side of the frame seat. A plurality of fasteners separately pass through the assembling holes and the meshed fabric and are fastened into the fixing holes, so that the frame seat with the meshed fabric is secured on the base.

Abstract: The invention includes an outer frame, fasteners, an inner frame, a supporting body and pressing strips. The outer frame has a surrounding trough. The fasteners are disposed in the surrounding trough. Each fastener has an engaging portion. The supporting body is made of a flexible material and has a loading side and a connecting side. The pressing strips are surroundingly attached on a periphery of the connecting side. An interval is kept between two adjacent pressing strips to provide flexibility. The supporting body covers the front of the inner frame. The pressing strips are fastened onto the rear of the inner frame. The inner frame with the supporting body is embedded into the surrounding trough to engage with the engaging portions of the fasteners.

Abstract: The invention includes an outer frame, fasteners, an inner frame, a supporting body and pressing strips. The outer frame has a surrounding trough. The fasteners are disposed in the surrounding trough. Each fastener has an engaging portion. The supporting body is made of a flexible material and has a loading side and a connecting side. The pressing strips are surroundingly attached on a periphery of the connecting side. An interval is kept between two adjacent pressing strips to provide flexibility. The supporting body covers the front of the inner frame. The pressing strips are fastened onto the rear of the inner frame. The inner frame with the supporting body is embedded into the surrounding trough to engage with the engaging portions of the fasteners.

Abstract: The auxiliary backrest for a chair includes a support and an auxiliary backrest body. The support has two rails. Each rail is formed by a surrounding wall and a side wall. An open trough is formed within the two rails. The trough has an inlet. The auxiliary backrest body has a back portion with a pair of elastic sheets. Each elastic sheet has a fixing end connected to the back portion and an elastic end corresponding to the two rails. Each elastic end has an insert portion inserted into the trough. A distance between two outer ends of the two insert portions is slightly greater than a width of the trough. When the insert portions are compressedly inserted into the trough, the elastic ends can be held between the rails by the elasticity thereof.

Abstract: The flexible support device is used for chair back tilting, which is installed under a cushion. The device includes a base, two driving members connected to the chair back, a pulling rod crossing the base and a spring disposed in the base. The base is connected to ends of the driving members. Two ends of the pulling rod are separately connected to two free ends of the two driving members. The pulling rod has a frame encompassing the spring. The frame has an action end blocking the spring. When the chair back is pressed to tilt rearward, the driving members are rotated to draw the pulling rod to move toward the chair back, and the action end of the frame is driven to compress the spring so as to make the chair back flexibly supported.

Abstract: The movable tablet includes a shaft fixed to an armrest and having a radial pin hole. A connecting seat has a first connecting portion toward the shaft and a second connecting portion. The first connecting portion is axially rotatably connected to the shaft. The second connecting portion has a through hole axially corresponding to the pin hole. A pin passes through the through hole and the pin hole to prevent the first connecting portion from rotating relative to the shaft. A tablet is rotatably connected to the second connecting portion. A releaser is disposed on the tablet to make the pin escape from the pin hole when the tablet is horizontally rotating so that the tablet can be turned vertically.

Abstract: The movable tablet includes a shaft fixed to an armrest and having a radial pin hole. A connecting seat has a first connecting portion toward the shaft and a second connecting portion. The first connecting portion is axially rotatably connected to the shaft. The second connecting portion has a through hole axially corresponding to the pin hole. A pin passes through the through hole and the pin hole to prevent the first connecting portion from rotating relative to the shaft. A tablet is rotatably connected to the second connecting portion. A releaser is disposed on the tablet to make the pin escape from the pin hole when the tablet is horizontally rotating so that the tablet can be turned vertically.

Abstract: The flexible support device is used for chair back tilting, which is installed under a cushion. The device includes a base, two driving members connected to the chair back, a pulling rod crossing the base and a spring disposed in the base. The base is connected to ends of the driving members. Two ends of the pulling rod are separately connected to two free ends of the two driving members. The pulling rod has a frame encompassing the spring. The frame has an action end blocking the spring. When the chair back is pressed to tilt rearward, the driving members are rotated to draw the pulling rod to move toward the chair back, and the action end of the frame is driven to compress the spring so as to make the chair back flexibly supported.

Abstract: The fastening structure includes an inner sleeve, a quick-release handle and an outer sleeve. The inner sleeve has an outer threaded conic surface, a through slot, shrinkable slots and claw plates between adjacent two of the shrinkable slots. The quick-release handle is provided at a bottom end of the inner sleeve for controlling a width of the through slot. The outer sleeve is used for connecting the footrest ring and has an inner threaded conic surface to screw the outer sleeve onto the inner sleeve.

Abstract: The armrest structure includes a connecting seat having a sleeve. A height adjustment rod is disposed in the sleeve and has two symmetric boards. Each of the boards is formed with recesses. A receiving room is formed between the two boards. An elevation rod is disposed in the sleeve. An end of the elevation rod has a projection received in the receiving room. Another end of the elevation rod has a connecting seat with a cylinder and a spring. An armrest set has a tube and an armrest connected atop the tube. The tube is received in the sleeve and sheathes the height adjustment rod and elevation rod. A top of the tube is formed with a channel for receiving a trigger. A fixing bar passes through the projection and is embedded into one of the recesses.

Abstract: The chair includes a cushion having a chassis, a back and an adjustment structure connected to the chassis. The adjustment structure includes a base frame and a back frame. The base frame has a main body with a connecting arm rotatably connecting the chassis. The back frame is connected between the back and the base frame and has a connecting portion connected to the base frame and a support substantially perpendicularly extending from the connecting portion toward the back. An arc-shaped bend portion is formed between the support and the connecting portion. A top of the support is connected to the back.

Abstract: The invention includes a frame, a back board and an adjustment set. The frame has a central trench and an adjustment board with limiting slots and two sliding slots. The back board is connected to the frame and has an opening. The adjustment set is connected between the frame and the back board and includes: a sliding seat having an engagement block received in the opening, and the engagement block having a recess with a through hole; a limiting body received in the recess, having a central bar in the through hole and an extending portion with a limiting bar in the limiting slots, and a C-shaped trench around the central bar; a torsion spring received in the C-shaped trench, two ends thereof protruding from the C-shaped trench and stopped by the recess; and two sliders received in the sliding slots. The sliders and the sliding seat are fixed to the back board.