Patent ID: 7600821
Filing Date: 2009-10-13
Classification: A47C,B60N

Abstract:
1. A seat comprising: a seat cushion; and a seat back including a seat back frame mounted on the seat cushion a backrest mounted on the seat back frame, and a flexible portion formed on the backrest, wherein the backrest is substantially net-shaped, and the backrest is provided in a tensioned state on the seat back frame, such that a horizontal tension in the backrest is minimized at a portion corresponding to a horizontal line set through upper rear iliac spines of a seated position of the user and increased gradually from a portion of the minimized tension, or such that a horizontal looseness is maximized at the portion corresponding to a horizontal line set through the upper rear iliac spines of the seated position and decreased gradually from a portion of the maximized looseness, wherein when a user is sitting on the seat, individual centers of a load situated at a plurality of regions, the regions presumed on left and right sides of a backrest surface symmetrically about a vertical central line of the seat back, are distributed outside a backrest area corresponding to a back region of the user, the backrest area defined by a straight line joining lower ends of left and right blade bones of the user, by a straight line joining upper ends of left and right iliac bones and by straight lines set above and along right and left lumbar iliocostal muscles.