Patent ID: 6755476
Filing Date: 2004-06-29
Classification: B60N

Abstract:
A tension structure for the seat back of a seat comprising:a substantially quadrilateral-shaped seat back frame, said seat back frame including a pair of spaced apart side sections, said side sections having first upper, middle, and lower regions; a pair of stop rings each mounted to the first lower region of each of said side sections; a tension assembly arranged within said seat back frame, said tension assembly comprising: right and left vertical bars having second upper, middle, and lower regions; and support means bridged between said right and left vertical bars; a pair of coil springs each connected between one of the side sections and one of the vertical bars at the upper regions thereof, a second pair of coil springs each connected between one of the side sections and one of the vertical bars at the middle regions thereof; and linear wire means connected between each of said stop rings and the vertical bars at the lower regions thereof to restrict movement of a lower area of said tension assembly; whereby when a person sits on said seat, displacement of the lower area of said tension assembly corresponding to a lumbar region of the person's back is more restricted than displacement of middle and upper areas of said tension assembly which correspond to the waist and shoulder regions respectively of the person's back.