US Patent 7396077 Seat structure with elastic suspension

A seat structure is comprised of a support frame having an elastic fabric sheet secured to the frame along opposed lateral sides of the frame and extends across a top seating portion or front part of a backrest thereof. In one embodiment of the invention one or two extensor members are displaceably positioned between the frame and the elastic fabric sheet to a permanent tensioning position where the elastic fabric sheet undergoes an upward displacement and stretching sufficient to support an intended load, herein a user person, thereon or thereagainst in a flexible suspension in the seating or backrest portion and free from contact with any hard surfaces.