Cushion with spatially varying lattice structures
A seat structure is configured to support an occupant. The seat structure includes a suspension. A seat cushion is arranged adjacent to the suspension. The seat cushion defines a plurality of variable effective property regions. At least one of the plurality of variable effective property regions includes a regular periodic lattice structure.
1. A seat structure configured to support an occupant, the seat structure comprising:
a suspension; and
a seat cushion arranged adjacent to the suspension,
wherein the seat cushion defines a plurality of variable effective property regions, wherein at least one of the plurality of variable effective property regions includes a regular periodic lattice structure, and
wherein the plurality of variable effective property regions includes a first modulus region including a first lattice structure having a first elasticity tensor and a second modulus region including a second lattice structure having a second elasticity tensor that is different than the first elasticity tensor.
2. The seat structure of claim 1 further comprising a seat cover material disposed upon the seat cushion.
3. The seat structure of claim 1 , wherein the seat cushion is produced using a manufactured fabric.
4. The seat structure of claim 1 , wherein the suspension comprises a plate including a plurality of through holes.
5. The seat structure of claim 1 , wherein the suspension comprises a manufactured fabric.
6. The seat structure of claim 1 , wherein the seat cushion comprises a urethane-based polymer.
7. The seat structure of claim 1 , wherein at least a portion of the seat cushion is fabricated by an additive manufacturing process.
8. The seat structure of claim 1 , wherein the seat cushion is produced using molding.
9. The seat structure of claim 1 , wherein the seat cushion is produced using at least one of weaving and/or knitting.
10. The seat structure of claim 1 , wherein the seat cushion comprises at least one region made of a periodic cellular material with open cells.
11. The seat structure of claim 1 , wherein the suspension is produced using at least one of weaving and/or knitting.
12. The seat structure of claim 1 , wherein the plurality of variable effective property regions limit excursion of static contact pressure under a seated occupant beyond 1.5 psi.
13. The seat structure of claim 1 , wherein locations and effective moduli of the plurality of variable effective property regions in the seat cushion are based upon at least one of a body pressure distribution map and a static pressure map.
14. A seat structure configured to support an occupant, the seat structure comprising:
a suspension; and
a seat cushion arranged adjacent to the suspension,
wherein the seat cushion defines a plurality of variable effective property regions, wherein at least one of the plurality of variable effective property regions includes a regular periodic lattice structure,
wherein the regular periodic lattice structure includes a plurality of unit cells each including first rods connected to second rods, wherein the first rods have a first stiffness and second rods have a second stiffness that is different from the first stiffness.
15. A seat structure configured to support an occupant, the seat structure comprising:
a suspension; and
a seat cushion arranged adjacent to the suspension,
wherein the seat cushion defines a plurality of variable effective property regions, wherein at least one of the plurality of variable effective property regions includes a regular periodic lattice structure, and
wherein the regular periodic lattice structure includes first unit cells and second unit cells, wherein the first unit cells include first rods having a first stiffness and the second unit cells include second rods having a second stiffness.
16. The seat structure of claim 15 , wherein a plurality of the first unit cells occupies the same volume as a single one of the second unit cells.
17. The seat structure of claim 15 , wherein the first unit cells have a first height and the second unit cells have a second height that is less than the first height.
18. The seat structure of claim 17 , wherein the first unit cells are more compliant than the second unit cells.
19. A seat structure configured to support an occupant, the seat structure comprising:
a suspension; and
a seat cushion arranged adjacent to the suspension,
wherein the seat cushion defines a plurality of variable effective property regions, wherein at least one of the plurality of variable effective property regions includes a regular periodic lattice structure,
wherein the seat cushion comprises at least one region made of a periodic cellular material with open cells, and
wherein the seat cushion enables an air flow rate of at least 20 ft 3 /min without explicitly defined macroscopic air flow passages.