Patent ID: 7434881
Filing Date: 2008-10-14
Classification: A47C

Abstract:
1. A dynamic chair providing automatic motion in a seat, the chair comprising: a chair base with center support; a seat having a bottom; a drive motor; a first motor drive wheel, the first motor drive wheel driven in a rotational manner by the drive motor; a first drive wheel belt, the first drive wheel belt driven by the first motor drive wheel; a second speed modification drive wheel, the second speed modification drive wheel driven in a rotational manner by first drive wheel belt; a third drive wheel, the third drive wheel attached to and driven by the drive shaft; a second drive wheel belt, driven by the third drive wheel; a cam connected parallel to and driven by the fourth drive wheel, the cam having a center of rotation, a high point daring the cam's rotation and a low point of the cam's rotation a first offset distance substantially equal to the difference of the distance from the high point of the cam to the cam's center of rotation and the distance from the low point of the cam to its center of rotation; a second offset distance which is the sum of the distances from the offset mounting points and to the center of rotation of each eccentric; a second control means providing second and third rotational degrees of freedom of movement to the seat, the second control means attached to mounting points on the left and right eccentrics, respectively, to mounting locations on a forward location of the seat's bottom, wherein the third and fourth drive wheels are configured in an unequal ratio of diameters within a range of 20:1 and 1:20, such that a changing, substantially ellipsoidal tilting pattern of movement is produced in the seat bottom.