Patent ID: 7044551
Filing Date: 2006-05-16
Classification: B60N

Abstract:
1. A seat structure including a back frame and a cushion frame comprising: a flat-type supporting member for a seat back supported by said back frame; a tension adjusting mechanism for adjusting a tension of said flat-type supporting member for the seat back; and a flat-type supporting member for a seat cushion elastically supported by said cushion frame separately from said flat-type supporting member for the seat back; wherein said tension adjusting mechanism comprises: a torsion bar disposed in a vicinity of a bottom end of said back frame along a width direction of the back frame; and a pelvis supporting plate composed of a plate member having predetermined width and length, connectedly disposed with said torsion bar, positioned in a rear of a pelvis of a seated person, and enforced in a direction pushed forward in a normal state, said flat-type supporting member for the seat back is engaged with a vicinity of a bottom end of said pelvis supporting plate at a bottom end thereof, and strained vertically on said back frame by an elastic force of said torsion bar; wherein said flat-type supporting member for the seat cushion is engaged with a front frame forming said cushion frame at a front end portion thereof, and elastically supported by a rear frame forming said cushion frame via spring members at a rear end portion thereof, and the spring members act as a tension adjusting mechanism of the flat-type supporting member for the seat cushion; wherein a first band member for the seat cushion is provided in layers at nearly central portion from front to back along a width direction on a back face of said flat-type supporting member for the seat cushion, and connected to a vicinity of one side portion of the flat-type supporting member for the seat cushion at one end, and engaged with a side frame corresponding to an other side portion of the flat-type supporting member for the seat cushion at an other end; wherein a second band member for the seat cushion is provided in layers in the vicinity of one side portion of said flat-type supporting member for the seat cushion in a direction from front to back, and connected to a vicinity of the front portion of the flat-type supporting member for the seat cushion at least at one end and engaged with the rear frame at an other end, so that a setting height of the flat-type supporting member for the seat cushion is maintained at a predetermined height.