Abstract: A chair chassis includes a base, a warped plate, a first adjustment member and a second adjustment member. The base including an upper cover, a lower cover and a front cover is arranged at a bottom surface of a seat of a chair. The warped plate is disposed under the upper cover of the base for connecting to a seat back of the chair. Two compression springs arranged in parallel with a certain interval are disposed between the first adjustment member and the warped plate for adjusting travel distance of the compression springs and changing a force of the seat back. The second adjustment member is used for lifting the chair by rotation of a second adjustment shaft. The chair chassis is fastened and adjusted by operating the second adjustment shaft to move along an axial direction. The chair chassis has simple structure, easy operation and improved applicability.

Abstract: A chair chassis includes a base, a warped plate, a first adjustment member and a second adjustment member. The base including an upper cover, a lower cover and a front cover is arranged at a bottom surface of a seat of a chair. The warped plate is disposed under the upper cover of the base for connecting to a seat back of the chair. Two compression springs arranged in parallel with a certain interval are disposed between the first adjustment member and the warped plate for adjusting travel distance of the compression springs and changing a force of the seat back. The second adjustment member is used for lifting the chair by rotation of a second adjustment shaft. The chair chassis is fastened and adjusted by operating the second adjustment shaft to move along an axial direction. The chair chassis has simple structure, easy operation and improved applicability.

Abstract: A chair chassis is revealed. The chair chassis includes a seat base, a middle base and an adjustment member. A sliding plate is connected to each side of the seat base. A sliding slot is arranged at a front and a rear end of each sliding plate and a pulley is arranged transversely between two sliding slots. The two pulleys connect to a tilting board. The middle base between the two sliding plates connects to the tilting board and the two sliding plates by the pulley on the front end. A third pulley slides over a slant part of the middle base. The adjustment member includes a rack, a locking piece and a lock adjustment rod for control of movement of the locking piece to be engaged with and separated from the rack. Thus users with various weights can use the same chair chassis and operate the chair chassis easier.

Abstract: A chair chassis is revealed. The chair chassis includes a seat base, a middle base and an adjustment member. A sliding plate is connected to each side of the seat base. A sliding slot is arranged at a front and a rear end of each sliding plate and a pulley is arranged transversely between two sliding slots. The two pulleys connect to a tilting board. The middle base between the two sliding plates connects to the tilting board and the two sliding plates by the pulley on the front end. A third pulley slides over a slant part of the middle base. The adjustment member includes a rack, a locking piece and a lock adjustment rod for control of movement of the locking piece to be engaged with and separated from the rack. Thus users with various weights can use the same chair chassis and operate the chair chassis easier.