Patent ID: 7708161

Claim:
A structure for a negative pressure vessel, comprising: a. a wall, separating an internal volume contained within said negative pressure vessel from an external volume lying outside said negative pressure vessel; b. wherein said wall is formed from a plurality of joined cells; c. wherein each of said plurality of joined cells has a first layer, a second layer, a third layer, a fourth layer, and a fifth layer, with each of said layers being made of tensile elements; d. wherein said first, second, third, fourth, and fifth layers are radially disposed outwardly from a central axis running down the middle of said negative pressure vessel, with said first layer being closest to said central axis, said second layer being further from said central axis than said first layer, said third layer being further from said central axis than said second layer, said fourth layer being further from said central axis than said third layer, and said fifth layer being furthest from said central axis; e. said first, second, and third layers being joined at a plurality of inner junctions, wherein each of said inner junctions is equidistant from said central axis at a first radius; f. said third, fourth, and fifth layers being joined at a plurality of outer junctions, wherein each of said outer junctions is equidistant from said central axis at a second radius, said second radius being greater than said first radius; g. wherein each of said tensile elements in said first layer connects one of said inner junctions to an adjacent inner junction, said tensile elements in said first layer bulging inward toward said central axis; h. wherein each of said tensile elements in said second layer connects one of said inner junctions to an adjacent inner junction, said tensile elements in said second layer being straight; i. wherein each of said tensile elements in said third layer connects one of said inner junctions to an adjacent outer junction, said tensile elements in said third layer being straight; j. wherein each of said tensile elements in said fourth layer connects one of said outer junctions to an adjacent outer junction, said tensile elements in said fourth layer being straight; and j. wherein each of said tensile elements in said fifth layer connects one of said outer junctions to an adjacent outer junction, said tensile elements in said fifth layer bulging outward away from said central axis.