Abstract: A back support for a chair includes a cover configured to be coupled to opposing sides of a chair frame. A strap is connected to the cover. A sled having a central portion is coupled to the strap, the sled is configured to pivot with respect to the chair frame and provide support to a user's back. The cover is configured to moveably connect to the chair frame between a low position and a high position. The sled is configured to pivot as the cover moves between the low position and the high position so that the central portion of the sled is substantially parallel to at least a portion of a membrane connected to the frame between the low position and the high position.

Abstract: A back support structure includes a frame, a support, a fulcrum member, and an adjustment mechanism. The support includes an upright member having a lower end and an upper end. The lower end of the upright member is connected to the frame at a first location. A support pad is connected to the upper end of the upright member. The fulcrum member has an upper portion and a lower portion. The upper portion is connected to the frame at a second location spaced vertically above the first location. The fulcrum member includes a fulcrum engaging the upright member between the upper and lower ends. The fulcrum member is moveable between a plurality of fulcrum positions. The adjustment mechanism includes an adjustment member connected to the frame and the lower portion of the fulcrum member. The adjustment member is adjustable to move the fulcrum member to the plurality of fulcrum positions.

Abstract: A back support for a chair includes a cover configured to be coupled to opposing sides of a chair frame. A strap is connected to the cover. A sled having a central portion is coupled to the strap, the sled is configured to pivot with respect to the chair frame and provide support to a user's back. The cover is configured to moveably connect to the chair frame between a low position and a high position. The sled is configured to pivot as the cover moves between the low position and the high position so that the central portion of the sled is substantially parallel to at least a portion of a membrane connected to the frame between the low position and the high position.

Abstract: A back support structure includes a frame, a support, a fulcrum member, and an adjustment mechanism. The support includes an upright member having a lower end and an upper end. The lower end of the upright member is connected to the frame at a first location. A support pad is connected to the upper end of the upright member. The fulcrum member has an upper portion and a lower portion. The upper portion is connected to the frame at a second location spaced vertically above the first location. The fulcrum member includes a fulcrum engaging the upright member between the upper and lower ends. The fulcrum member is moveable between a plurality of fulcrum positions. The adjustment mechanism includes an adjustment member connected to the frame and the lower portion of the fulcrum member. The adjustment member is adjustable to move the fulcrum member to the plurality of fulcrum positions.