Helmet with shear force management
View Patent ↗The present disclosure relates to a cushion for use in a helmet comprising an outer shell for impact with an incoming force, the cushion disposed between the outer shell and a head when the helmet is worn, the cushion comprising: a sealed bladder comprising a flexible membrane; a pad housed within the bladder, said pad comprising a compressible member having interstices open to the exterior of the pad; and a liquid within the interior of the bladder; wherein said pad absorbs at least some of said liquid when uncompressed and expels said liquid when compressed; and wherein the volume of liquid within the bladder is sufficient to allow opposing surfaces of the bladder to be displaced in a shearing motion relative to each other when the cushion is compressed and subjected to shear forces, to decouple shear forces between said helmet and the head.
1. A cushion for managing shear forces in a body armor, the cushion comprising:
a sealed flexible bladder filled with a liquid and containing a compressible and resilient solid element therein,
wherein the solid element fills the interior of the bladder when uncompressed, and the solid element is detached from at least an upper or lower surface of the bladder to permit the liquid to flow at least partially around the element.
2. The cushion of claim 1 wherein the liquid is oil.
3. The cushion of claim 1 wherein the solid element has a density that is less than the liquid.
4. The cushion of claim 1 wherein the solid element comprises open cell foam or an open lattice whereby the liquid is configured to be expelled from the element and absorbed into the element when respectively compressed and decompressed.
5. The cushion of claim 1 wherein the solid element comprises a closed cell material.
6. A body armor system comprising an outer impact-receiving layer and at least one cushion according to claim 1 interior to said layer for managing shear forces impacting the outer impact-receiving layer.
7. The system of claim 6 wherein the solid element is detached from at least an upper or lower surface of the bladder.
8. The system of claim 6 wherein the solid element has a density that is less than the liquid.
9. The system of claim 8 wherein the solid element comprises open cell foam or an open lattice whereby the liquid is expelled and absorbed from the element when compressed and decompressed.
10. The system of claim 8 wherein the solid element comprises a closed cell material.
11. The system of claim 6 further comprising an energy absorbing layer between the outer impact-receiving layer and the at least one cushion.
12. The system of claim 11 wherein the energy absorbing layer comprises rigid foam.
13. The system of claim 6 wherein the outer impact-receiving layer comprises a rigid shell.
14. The system of claim 6 , further comprising a helmet.
15. The system of claim 14 wherein the helmet further comprises an inner skull grip and the at least one cushion is located between the skull grip and the wearer's head.
16. The system of claim 14 , comprising an array of cushions arranged at the front, sides and rear of the helmet.
17. The system of claim 16 wherein the array of cushions comprises at least one cushion at the top of the helmet.
18. The system of claim 6 further comprising at least one force redirection cushion configured for redirecting a force impacting the outer impact-receiving layer in a direction away from the direction which causes the highest risk of injury.
19. A method of decoupling the body of a user from angular or rotational forces impacting on body armor worn by the user, the method comprising use of the system of claim 6 .