Patent ID: 6817674
Filing Date: 2004-11-16
Classification: B60N

Abstract:
A seat structure comprisinga cushioning structure having a seat cushioning member for a seat cushion and a back cushioning member for a seat back, wherein said seat cushioning member and said back cushioning member are provided as a tension structure having a tension field formed from an elastic member, and at least one of said seat cushioning member and back cushioning member is structured to vary the tension in the tangential direction by changing the strain energy in accordance with the magnitude of an excitation force to be an input, and different damping characteristics are exhibited according to the magnitude of the excitation force to be an input in such a manner that the damping characteristics function at a small damping ratio for an input of a small excitation force, and the damping characteristics function at a large damping ratio for an input of a large excitation force; wherein said cushioning structure forms a vibration system in which an arbitrary portion of the seat cushioning member positioned more front than the vicinity of the boundary of the seat cushion portion and the seat back portion and/or an arbitrary of the back cushining member positioned upper than the vicinity of said boundary portion portion serves as an free end by putting an extendable direction on the plane surface of the cushioning structure along the back-and-forth direction of the seat cushion portion and along the vertical direction of the seat back portion respectively, and by holding the vicinity of the boundary portion of the seat cushion portion and the seat back portion; and wherein in at least one of said seat cushioning member and back cushioning member in which said vibration system is formed, tension in the tangential direction is varied by changing the strain energy of the tension structure formed from an elastic member in accordance with the excitation force to be an input, and at least the other of said seat cushioning member and back cushioning member includes a portion exhibiting relatively high spring characteristics in the normal line direction of the tension structure, and has a structure in which an excitation force inputted from the normal line direction to said cushioning member is scatterable into an excitation force in the tangential direction by a combined function of these different characteristics.