Protective foam with skin
View Patent ↗A protective foam layer is provided. The protective layer has a foam substrate that is at least partially enclosed by a formed skin adjacent the outer surface of the foam substrate. The formed skin is substantially non-porous. The combination of the foam substrate with the formed skin results in a protective layer that is effective to absorb and/or dissipate impact force for both high- and low-speed impacts that can be experienced during a sporting event such as cycling. The formed skin can also be provided with a plurality of protective zones having vent holes through the formed skin to regulate the degree of energy absorption in the respective zones. In this manner, a single continuous protective foam layer can be provided having multiple protective zones having distinct energy absorption characteristics instead of providing discrete protective layers that must be joined or meet at a seam. According to the invention, by providing such a continuous protective layer with no such seams, a known failure mode in protective equipment is eliminated.
1. A protective layer comprising a viscoelastic foam substrate and a flexible skin at least partially enclosing said foam substrate, said flexible skin having a plurality of vent holes provided therein in a protective zone of said flexible skin overlying said foam substrate, said vent holes providing fluid communication between the ambient environment and a portion of the surface of said foam substrate that underlies said protective zone, said flexible skin being a barrier to exhaustion of gas pressure from within said foam substrate to the ambient atmosphere on impact of said foam substrate, said plurality of vent holes being effective to regulate the local rigidity of said protective layer by permitting gas to escape at said protective zone at a rate that is dependent on the number and size of said vent holes through said flexible skin in said protective zone, wherein said viscoelastic foam substrate is a continuous foam layer in the vicinity under said vent holes.
2. A protective layer according to claim 1 , said skin being formed integrally with said foam substrate.
3. A protective layer according to claim 1 , said skin being separately provided from said foam substrate and being subsequently molded thereto.
4. A protective layer according to claim 1 , said foam substrate comprising flexible polyurethane foam, said skin comprising a formable thermoplastic.
5. A protective layer according to claim 1 , said skin having a first protective zone and a second protective zone, each said protective zone of said skin having a plurality of vent holes provided therein effective to regulate the rigidity of said protective layer adjacent said protective zone, said protective layer being more rigid adjacent said first protective zone than adjacent said second protective zone by virtue of the relative size and/or density of vent holes provided in said first protective zone compared to in said second protective zone.
6. A protective layer according to claim 5 , said protective layer being a seamless protective layer across both said first and said second protective zones.
7. A protective layer according to claim 1 , said foam substrate having a density of 104 kg/m 3 +/−30%.
8. A protective layer according to claim 1 , said foam substrate comprising a partially closed-cell polymeric foam.
9. A protective layer according to claim 1 , said protective layer being a seamless protective layer and having a first protective zone and a second protective zone, said protective layer being more rigid adjacent said first protective zone than adjacent said second protective zone, said foam substrate being seamless in the region of said first and said second protective zones.
10. A protective layer according to claim 1 , said skin having a porosity at least 10% lower than an outer surface of said foam substrate.
11. A protective layer according to claim 1 , said foam substrate being effective to recover to a substantial proportion of its original shape following deformation thereof resulting from an impact to said protective layer.
12. A protective layer according to claim 1 , said foam substrate being effective to recover to at least 90% its original shape following deformation thereof from a high speed impact.
13. A protective layer according to claim 1 , wherein said protective layer exhibits energy absorptive properties of a flexible or semi-rigid foam at impact speeds less than 5 mph thereby being effective to absorb impact energy through non-destructive, recoverable deformation of the foam substrate, and wherein said protective layer exhibits energy absorptive properties of a rigid foam at impact speeds greater than 15 mph thereby being effective to dissipate and absorb impact energy through deformation of the foam substrate.
14. A protective layer according to claim 13 , said foam substrate being effective to recover to a substantial proportion of its original shape following deformation thereof resulting from an impact to said protective layer at a speed of greater than 15 mph.
15. A protective layer according to claim 14 , said foam substrate being effective to recover to at least 90% its original shape following said deformation thereof.
16. A protective layer according to claim 13 , said skin having a first protective zone and a second protective zone, each said protective zone of said skin having a plurality of vent holes provided therein effective to regulate the local rigidity of said protective layer adjacent said protective zone.
17. A protective layer according to claim 16 , said protective layer being more rigid adjacent said first protective zone than adjacent said second protective zone.
18. A protective layer according to claim 13 , said foam substrate being seamless in the region of said first and said second protective zones, said protective layer being more rigid adjacent said first protective zone than adjacent said second protective zone.
19. A protective layer according to claim 1 , wherein said plurality of vent holes are provided as an array of vent holes located in said protective zone.
20. A protective layer according to claim 1 , further comprising a hard outer shell disposed adjacent said skin opposite said foam substrate.
21. A protective layer according to claim 1 , said viscoelastic foam substrate being seamless.