Chair with lumbar support and conforming back

Abstract

A task chair including a seat support structure, a backrest frame attached to the seat support structure, and a backrest supported by the backrest frame. The backrest includes a back support surface which may ergonomically conform to a seated user when the user shifts positions while sitting in the chair. The back support surface includes rigid and flexible portions connected to one another, the flexible portions allowing resilient flexing of the back support surface to create conformance zones which dynamically support the back of a seated user in an ergonomic manner.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation-in-part of U.S. patent application Ser. No. 10 / 315,838, entitled CHAIR WITH LUMBAR SUPPORT AND CONFORMING BACK, filed on Dec. 10, 2002, which claims the benefit under Title 35, U.S.C. § 119(e) of U.S. Provisional Patent Application Ser. No. 60 / 340,673, entitled CHAIR WITH LUMBAR SUPPORT AND CONFORMING BACK, filed on Dec. 14, 2001.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to chairs, and in particular, to a task chair for supporting the back of a seated user in an ergonomic manner. [0004] 2. Description of the Related Art [0005] Task chairs are commonly used by persons while working in a seated position in offices or other occupational environments. Typically, such chairs include a caster wheel assembly supporting the chair for rolling movement over a floor surface, as well as a number of manual adjustment features to allow the user to adjust the sh...

AI Technical Summary

Benefits of technology

[0010] The backrest is connected to the seat support structure by a backrest frame, which may include one or more support arms which may be moveably mounted to the seat support structure. The support arms additionally include support portions extending therefrom which are in abutment with the rigid portions of the backrest to define substantially rigid flex points about which the back support surface may flex to conform to the back of a seated user. In addition, the backrest may be connected to the backrest frame at one or more flex joints which facilitate flexing of the lumbar portion of the backrest outwardly or forwardly to support the lumbar area of the back of a seated user when the user leans backwardly against an upper portion of the backrest. The flex joints may flex together or may flex independently from one another, and additionally, the flex joints may flex to a varying extent with respect to one another.

[0013] Advantageously, the present task chair in one form thereof includes a back support surface having rigid portions which may be configured to provide a relatively firm support to the lumbar region or another region of the back of a seated user, and flexible portions which facilitate resilient flexing movement of the backrest and which provide a relatively cushioning support to certain areas of the back of a seated user in selected zones of the back support surface. The upper portion of the backrest and the lumbar portion of the backrest may flex about flex points provided by the backrest frame to dynamically conform to the upper and lumbar regions of the back of a seated user as the seated user shifts positions while sitting in the chair.

Problems solved by technology

Such backrests typically allow only a very limited degree of adjustment, in terms of both the movement of the lumbar support and the reclining of the backrest.

Further, adjustment of the backrest is typically performed by manual operation of controls which may be difficult to locate and manipulate.

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