Patent ID: 7008017

Claim:
A dynamic chair providing automatic motion in a seat, the chair comprising: a base; a seat having a bottom, the seat bottom having a first seat bottom mounting point and a second seat bottom mounting point; a support means disposed between the base and the seat bottom; a drive motor; a first drive wheel driven in a rotational manner by the drive motor, the first drive wheel having a first mounting point offset from the center of the first drive wheel; a first control means providing a first rotational degree of freedom of movement to the seat, the first control means attached between the first offset mounting point and the first seat bottom mounting point; a second drive wheel driven in a rotational manner by the first drive wheel; a crankshaft having a first crankshaft end and a second crankshaft end, the first crankshaft end connected to the second drive wheel and rotatably driven by the second drive wheel, the second crankshaft end having an eccentric providing a second offset mounting point offset from the center of the second crankshaft end; a second control means providing a second rotational degree of freedom of movement to the seat, the second control means attached between the second offset mounting point and the second seat bottom mounting point; wherein the first drive wheel and the second drive wheel are configured in a nonequal ratio of diameters within a range of 20.0:1.0 and 1.0:20.0, such that a changing, substantially ellipsoidal pattern of movement is produced in the seat bottom.