Multi-layer helmet and method for making the same
A protective helmet to be worn by a player engaged in a sport comprises a flexible outer shell and a multi-layer liner assembly disposed within the outer shell. The multi-layer liner assembly includes an inner-layer, a middle-layer and an outer-layer, and permits relative rotational movement between said layers when the helmet is worn by the player and receives an impact. The inner-layer is made from a first material with a first density and is mechanically coupled to the outer-layer without adhesive. The outer-layer is made from a second material with a second density that is greater than the first density of the inner-layer. The middle-layer is made from a third material that has a third density that is greater than the first density. The outer-layer also has a thickness that is greater than a thickness of the inner-layer and varies between a front region of the outer-layer and a crown region of the outer-layer.
1. A protective helmet to be worn by a player engaged in a sport, the protective helmet comprising:
an outer shell;
a multi-layer liner assembly disposed within the outer shell, the multi-layer liner assembly including an inner-layer and an outer-layer, said multi-layer liner assembly permits relative rotational movement between said layers when the helmet is worn by the player and receives an impact;
wherein the inner-layer is positioned adjacent to the player's head when the protective helmet is worn by the player and is made from a first material with a first density, and wherein the inner-layer is mechanically secured within the outer shell without using an adhesive;
wherein the outer-layer is positioned adjacent to an inner surface of the outer shell and the outer-layer is made from a second material with a second density that is greater than the first density of the inner-layer, and wherein said outer-layer has: (i) a thickness at a location in a rear region that is greater than a thickness at a location in a rear region of the inner-layer and (ii) a thickness at a location in a front region that is different than a thickness at a location in a crown region of the outer-layer.
2. The protective helmet of claim 1 , further comprising a middle-layer that is positioned between (i) an outer surface of the inner-layer and (ii) an inner surface of the outer-layer, said middle-layer has a thickness that is less than the thicknesses of each of the inner-layer and outer-layer and is made from a third material.
3. The protective helmet of claim 2 , wherein the inner-layer has a plurality of channels that extend completely through the inner-layer and upward from a lowermost edge of the inner-layer.
4. The protective helmet of claim 1 , further comprising a middle-layer positioned between the outer-layer and inner-layer, and wherein an extent of the middle layer positioned forward of the rear region is omitted from the multi-layer liner assembly.
5. The protective helmet of claim 2 , wherein the middle-layer has a density that is greater than 65 grams per liter.
6. The protective helmet of claim 2 , wherein the middle-layer underlies less than 90% of the inner surface of the outer-layer.
7. The protective helmet of claim 2 , wherein the thickness of the inner layer does not exceed 25 mm and the inner layer has a density that is between 10 grams per liter and 50 grams per liter.
8. The protective helmet of claim 1 , wherein the inner-layer is configured to absorb a first impact type while the outer-layer is configured to absorb a second impact type, and wherein the first impact type has less energy than the second impact type.
9. The protective helmet of claim 1 , wherein at least an extent of the inner layer is configured to move relative to an extent of the outer-layer when the helmet is worn by the player and receives an impact.
10. The protective helmet of claim 1 , wherein an inner surface of the inner-layer is custom formed to match a topography of the player's head.
11. The protective helmet of claim 1 , wherein a boundary condition is provided between the layers of the multi-layer liner assembly to manage energies received from an impact to the helmet.
12. The protective helmet of claim 1 , wherein multi-layer liner assembly includes a movement limiter that limits the relative movement between the inner-layer and the middle-layer.
13. A protective sports helmet to be worn by a player, the protective sports helmet comprising:
a flexible outer shell;
a multi-layer liner assembly disposed within the flexible outer shell, the multi-layer liner assembly including an inner-layer and an outer-layer, said multi-layer liner assembly permits relative rotational movement between said layers when the helmet is worn by the player and received an impact;
wherein the inner-layer is positioned adjacent to the player's head when the protective helmet is worn by the player and is configured to absorb a first impact type and has a density between 20 and 50 grams per liter;
wherein the outer-layer is positioned adjacent to an inner surface of the flexible outer shell and the outer-layer is configured to absorb a second impact type having greater energy than the first impact type, and wherein said outer-layer has a thickness at a location in a front region of the outer-layer that is different than a thickness at a location in a crown region of the outer-layer.
14. The protective helmet of claim 13 , further comprising a middle-layer that is positioned between (i) an outer surface of the inner-layer and (ii) an inner surface of the outer-layer, said middle-layer has a plurality of channels extending completely through the middle-layer.
15. The protective helmet of claim 13 , further comprising a middle-layer that is positioned between (i) an outer surface of the inner-layer and (ii) an inner surface of the outer-layer, wherein an extent of the middle-layer is removed from the middle-layer to form an opening in said middle-layer.
16. The protective helmet of claim 14 , wherein a portion of the middle-layer has a thickness that is less than 4 millimeters.
17. The protective helmet of claim 13 , wherein the inner-layer is made from a first material with a first density and the outer-layer is made from a second material with a second density, and wherein the first density is less than the second density.
18. The protective helmet of claim 13 , wherein multi-layer liner assembly includes a movement limiter that limits the movement between the inner-layer and the middle-layer.
19. The protective helmet of claim 13 , wherein the inner-layer is mechanically coupled to the outer-layer by a snap when: (i) a central snap portion extends through an opening in the outer-layer and (ii) a top snap portion is positioned within an extent of the outer-layer.
20. The protective helmet of claim 17 , further comprising a middle-layer; and
wherein the middle-layer has a thickness that is less than the thicknesses of each of the inner-layer and outer-layer and is made from a third material.
21. The protective helmet of claim 20 , wherein at least an extent of the inner layer is configured to move relative to an extent of the outer-layer when the helmet is worn by the player and receives an impact.