Abstract: A distance adjustment device for a chair includes a guide rail, a movable plate slidably mounted on the guide rail, a movable handle pivotally mounted on the movable plate and having a first end detachably engaged with the guide rail, and a fixed handle secured on the movable plate and located opposite to a second end of the movable handle. Thus, the user only needs to hold the push portion of the movable handle and the grip portion of the fixed handle by his one hand to unlock and move the movable plate, so that the distance adjustment device is operated by the user's one hand.

Abstract: An adjustable chassis for a chair includes a base member, a support member, and two support levers. Thus, the drive lever of the base member is drawn and moved by the first wire so as adjust the height of the chair seat relative to the adjustable chassis. In addition, the locking plate of the base member is drawn and moved by the second wire so as adjust the inclined angle of the chair backrest relative to the adjustable chassis. Further, the locking block is drawn and moved by the third wire so as adjust the position of the chair seat relative to the adjustable chassis.

Abstract: An armrest assembly includes an armrest support, a cover plate, a rotation plate, an armrest plate, a positioning block, and a locking barrel. Thus, the armrest plate is rotatable relative to the armrest support to change the angle between the armrest plate and the armrest support so as to change the horizontal swivel angle of the armrest assembly. In addition, the horizontal swivel angle of the armrest assembly is adjusted freely to fit the practical requirement of different users, thereby providing a comfortable sensation to the users.

Abstract: A distance adjustment device for a chair includes a guide rail, a movable plate slidably mounted on the guide rail, a movable handle pivotally mounted on the movable plate and having a first end detachably engaged with the guide rail, and a fixed handle secured on the movable plate and located opposite to a second end of the movable handle. Thus, the user only needs to hold the push portion of the movable handle and the grip portion of the fixed handle by his one hand to unlock and move the movable plate, so that the distance adjustment device is operated by the user's one hand.

Abstract: An adjustable chassis for a chair includes a base member, a support member, and two support levers. Thus, the drive lever of the base member is drawn and moved by the first wire so as adjust the height of the chair seat relative to the adjustable chassis. In addition, the locking plate of the base member is drawn and moved by the second wire so as adjust the inclined angle of the chair backrest relative to the adjustable chassis. Further, the locking block is drawn and moved by the third wire so as adjust the position of the chair seat relative to the adjustable chassis.

Abstract: A multi-stage backrest assembly for a chair includes a support frame, a back support mounted on the support frame, a head support mounted on the support frame, and a waist support pivotally mounted on the back support. Thus, the backrest assembly has a pivotable function so as to fit the curve of the user's body ergonomically, thereby providing a comfortable effect to the user. In addition, the locking tube of the crossbar of the back support is adjustably mounted on the respective support rod of the support frame, so that the back support is adjustably mounted on the support frame to adjust the height of the back support so as to fit users of different statures.

Abstract: A multi-stage backrest assembly for a chair includes a support frame, a back support mounted on the support frame, a head support mounted on the support frame, and a waist support pivotally mounted on the back support. Thus, the backrest assembly has a pivotable function so as to fit the curve of the user's body ergonomically, thereby providing a comfortable effect to the user. In addition, the locking tube of the crossbar of the back support is adjustably mounted on the respective support rod of the support frame, so that the back support is adjustably mounted on the support frame to adjust the height of the back support so as to fit users of different statures.

Abstract: A multi-stage backrest assembly includes a support frame, a back plate, a head plate, a waist plate, a first elastic swivel device, and two second elastic swivel devices. Thus, the multi-stage backrest assembly has a pivotable function so as to fit the curve of the user's body ergonomically, thereby providing a comfortable effect to the user.

Abstract: An adjustable armrest device has an armrest seat, a slide seat disposed on the armrest seat, and a pivot connection seat disposed on the slide seat. A disk is inserted in a center hole of the pivot connection seat. Two screw rods are disposed on the slide seat and inserted in two through holes of the disk. The pivot connection seat is disposed on an armrest holder stably. A pad is disposed on the armrest seat. A pivot post is inserted through the pad and inserted in the circular hole.

Abstract: An improved adjustable armrest for use on a chair is particularly related to an adjustable armrest in connection to a pneumatically operated cylinder permitting the armrest body to be vertically lifted up by actuation of a control stick or lowered down by a manual force against the armrest body. An armrest mount having tracks defined thereon for mounting of the armrest body permits the armrest to be slidably adjusted back and forth. The armrest mount with the armrest body is secured to a housing having a vertical hole for receiving the cylinder having one end engaged with the underside of a bottom bracket which is secured to the armrest mount. The cylinder housed in a tubular sleeve is fixed at the bottom end thereof to a support bracket and is engaged with a hand operated stick at the top end so that the actuation of the control stick results in the extension of the cylinder and the armrest body accordingly.