Helmet omnidirectional energy management systems

1. A helmet, comprising:

an outer shell;

an outer liner directly coupled, on a first side facing away from a wearer when worn, to the outer shell and having at least one concave recess on an opposing second side;

an isolation disk comprising:

an outer side and an opposing inner side,

at least one convex protrusion that is at least partially disposed within the at least one concave recess of the outer liner, and

at least one concave recess on the opposing inner side; and

an inner liner having at least one convex protrusion disposed at least partially within the at least one concave recess on the opposing inner side of the isolation disk.

2. The helmet of claim 1 , wherein the isolation disk comprises a generally circular disk.

3. The helmet of claim 2 , wherein the isolation disk further comprises a flange extending around a circumfery of the generally circular disk.

4. The helmet of claim 1 , wherein the at least one convex protrusion of the isolation disk has a shape that is complementary to a shape of the at least one concave recess of the outer liner.

5. The helmet of claim 1 , wherein the at least one concave recess of the isolation disk has a shape that is complementary to a shape of the at least one convex protrusion of the inner liner.

6. The helmet of claim 1 , further comprising a mechanism for preventing at least one of over-rotation and/or over-translation of the inner liner relative to the outer liner.

7. The helmet of claim 6 , wherein the mechanism comprises at least one flange extending from an outer surface of the inner liner and at least partially disposed in engagement with a corresponding recess in the outer liner.

8. A helmet, comprising:

an outer shell having an inner side configured to face a wearer's head;

an outer liner having a first side facing away from the wearer when worn and an opposing second side, wherein the outer liner is disposed within the inner side of the outer shell and directly coupled on the first side to the outer shell;

at least one isolation disk disposed between and coupled to the outer liner and an inner liner, wherein the inner liner is disposed within the inner side of the outer shell and coupled to the opposing second side of the outer liner by the at least one isolation disk;

at least one flange extending from an outer surface of the inner liner and disposed in engagement with a corresponding recess in the outer liner for preventing over-rotation, over-translation, or over-rotation and over-translation of the inner liner relative to the outer liner; and

wherein the at least one isolation disk is resilient to provide omnidirectional movement of the inner liner relative to the outer liner and the outer shell and to return the inner liner toward an initial resting position relative to the outer liner and the outer shell after an external impact to the outer shell.

9. The helmet of claim 8 , wherein the at least one flange is configured to allow for controlled lateral or rotational displacement of the inner liner such that, once the inner liner moves a predetermined distance relative to the outer liner, the flange will abut or engage one or more walls of the corresponding recess in the outer liner, thereby stopping movement of the inner liner relative to the outer liner.

10. The helmet of claim 8 , wherein the inner liner comprises expanded polypropylene and wherein the outer liner comprises expanded polystyrene.

11. The helmet of claim 8 , wherein the at least one isolation disk has a shape that is complementary to a shape of the recess of the outer liner.

12. The helmet of claim 11 , wherein the at least one isolation disk has a shape that is complementary to a shape of at least one convex protrusion of the inner liner.