| 主权项 |
1. A chair comprising:
a chair seat to support the weight of a user; a chair base to hold the chair seat above the ground; a chair back to support the back of the user and adapted to tilt forwards and backwards; and a dynamic lumbar support including a cushion back support having a first protruding shape that engages and supports the user's lower back when the user sits erect in the chair and the chair back tilts forwards, said cushion back support changing to a second flattened shape when the user reclines in the chair and leans back so that the chair back tilts backwards, a tilt pressure-responsive rod extending horizontally through said chair back and coupled to said cushion back support, a tension strap interconnected between said tilt pressure-responsive rod and the chair base, said tension strap rotating backwards relative to said chair base in response to the chair back tilting backwards to cause said tilt pressure-responsive rod to move up through the chair back and thereby apply a pulling force to said cushion back support to cause the shape of said cushion back support to change from its first protruding shape to its second flattened shape, and said tension strap rotating forwards relative to said chair base in response to the chair back tilting forwards to cause said tilt pressure-responsive rod to move down through the chair back and thereby apply a pushing force to said cushion back support to cause the shape of said cushion back support to change from its second flattened shape back to its first protruding shape. |
