PROGRESSIVELY CURVED LUMBAR SUPPORT FOR THE BACK OF A CHAIR

摘要

A progressively curved lumbar support located within the back of an office or home chair to enable a user to be seated close to a work surface (e.g., a desk or a table). The chair back tilts backwards and forwards when the user shifts his weight back and forth. The lumbar support includes a cushion back support manufactured from a resilient material that is responsive to a compressive force applied thereto when the user reclines against the chair back. In particular, a tilt pressure-responsive rod rides up and down over a pair of inclined guide blocks to cause the cushion back support to change its shape from a convex configuration at which to support the user's lower back and maintain a proper posture when the user sits erect and the chair back stands upright to a relatively flattened configuration when the chair back tilts backwards.

主权项

1. A chair comprising:
a seat to support the weight of a user; a base to hold the seat above the ground; and a back to support the back of the user, said back being adapted to tilt forwards and backwards and including: a cushion back support having a curved configuration to engage and support the user's lower back when the user sits erect in the chair and the chair back tilts forwards, and a tilt pressure-responsive rod moving in opposite directions within the chair back and over said cushion back support in response to said chair back tilting forwards and backwards to cause said cushion back support to progressively change its shape between said curved configuration and a relatively flattened configuration depending upon the location of said tilt pressure-responsive rod within said chair back.