Knit seat back for an office chair

An office-type chair, comprising:

• a ground engaging base;
• a height adjustable pedestal extending upwardly from the base;
• a seat supported on the pedestal and forming a surface for supporting a user seated on the chair;
• an upright back frame supported on one of the seat and the pedestal, the back frame extending upwardly from the seat;
• a weft knit back support attached to the back frame and including a lower edge adjacent the seat, an upper edge opposite the lower edge, and a pair of lateral side edges, wherein the back support includes a forward layer formed of a first yarn, the forward layer facing the user, a rear layer formed of a second yarn, the rear layer opposite the forward layer, and an inlay between the forward layer and the rear layer;
• wherein the forward layer and rear layer are knit with a predetermined pattern defined by cross points of the first and second yarns where the forward layer and rear layer are looped with one another and pinch the inlay to hold the inlay in place with respect to the forward and rear layers, wherein at the crossing points the inlay is flattened from a first inlay thickness to a second, narrower inlay thickness;
• wherein the back support includes a first region and a second region, the first and second regions each located in positions associated with a particular position on the back of a user, the first region having an increase density of cross points than the second region to provide differentiation in cushioning between the first and second regions due to the reduced density of crossing points providing reduced flattening of the inlay within the second region.

A back support for an office type chair, comprising:

• a back support frame;
• a first woven material attached to the back support frame;
• and
• a second material woven with the first material as an inlay within the first material;
• wherein the first and second materials are woven according to a predetermined knit pattern using a weft knitting process to form a first layer and a second layer of the first material, the first layer and the second layer crossing one another at cross points, the second material inlayed between the first and second layers such that it is held in position with respect to the first material at the cross points;
• wherein the knitting program differentiates the number of cross points by at least a first region and a second region in order to provide cushioning levels that vary by region across the back support.