Patent ID: 7303235

Claim:
A chair for use in a mass seating venue comprising: at least one base having an upper mounting portion and a lower mounting portion; a seat back mounted to the upper mounting portion of the base; a seat support pivotally mounted to the base for movement between a first lowered position and a first raised position about a first pivot axis and the seat support is biased into the first raised position by a first spring acting between the seat support and the base; a seat pivotally mounted to the seat support for movement between a second lowered position and a second raised position about a second pivot axis different than the first pivot axis, and biased into the second raised position by a second spring acting between the seat and the seat support; and a hinge assembly comprising a first mounting bracket mounted to the seat and a second mounting bracket mounted to the seat support, the first mounting bracket being supported for pivotal movement with respect to the second mounting bracket by a bearing; wherein the seat support comprises an arm connecting the first pivot axis with the second pivot axis and the second pivot axis moves with respect to the first pivot axis when the seat support is moved relative to the base; and wherein the second spring comprises a torsion spring acting between the first and second mounting brackets around the bearing.