Abstract: A chair of modular construction having modules that form the basic chair with additional modules that can be added to the chair without changing the basic construction thereof.

Abstract: An ergonomic chair includes a four-bar linkage arrangement wherein a lower frame member is provided with a rigid front support and a rigid rear support with a seat member pivotably connected to the front support. A back rest has an upper support pivotably connected at an upper end of the rear support of the lower frame member. A link member pivotably connects at a first end to a rear support of the seat member and at second end to a lower support of the back rest. This novel arrangement permits tilting movement of the backrest rearwardly relative to the lower frame member causing elevation of a rear portion of the seat member, permitting the feet to remain on the floor and alleviating pressure on the user's thighs, while rotation occurs closely coincident with the pivot axis of the user's hips and while maintaining a generally uniform gaze line.

Abstract: A chair back is disclosed and includes a mesh material connected to a two-piece carrier, the carrier being deformable and stretchable. The carrier has a bottom edge including a groove and is engageable by tabs attached to a transverse member of a chair frame assembly. The upper ends of the carrier each includes an opening for receiving a spherical end portion of the upper end of the chair frame assembly. Engagement of the carrier with the chair frame assembly is accomplished by stretching the carrier and mesh between the transverse member and the spherical end portions. The chair back includes a lumbar support which is mounted to slide along the side edges of the carrier and along vertical supports of the chair frame assembly, the lumbar support causing the chair to tension forwardly. The chair back is pivotal under the influence of a chair user and is pivotally connected to the chair seat so as to cause the chair seat to also pivot in response.

Abstract: A chair of modular construction having modules that form the basic chair with additional modules that can be added to the chair without changing the basic construction thereof.

Abstract: A lumbar support for a chair having a flexible back, includes at least one generally vertical support member disposed to the rear of the chair back. A transverse member engages the vertical support and has opposed ends provided with grippers for gripping opposed edges of the flexible back. The transverse member is configured to force the opposed edges of the flexible back forwardly of the chair back in the lumbar region of the user to provide support therefor. The transverse member may also be configured to slide on the vertical support to provide for height adjustability of the lumbar support of the fabric.