| 主权项 |
1. A helmet for protecting a wearer from successive impacts, the helmet comprising:
a head cap having inner and outer surfaces, the head cap surfaces being generally head-shaped and not spherical, the head cap adapted to surround at least a portion of the cranial part of a wearer's head, and being sufficiently securable thereto such that when secured to the wearer's head, at least the inner surface of the head cap substantially follows a motion of the surrounded cranial portion of the head during an impact to the helmet containing a normal force component and a tangential force component; a strap assembly connected to the head cap and adapted to surround at least one of the chin and the jaw of the wearer enabling at least in part releasably securing the head cap to the wearer's head, the head cap being connected to the strap assembly at least one of two ways: directly, and indirectly through at least one additional element; an outer shell comprised of a hard, impact resistant material, the outer shell having inner and outer surfaces, the outer shell surrounding at least a portion of the head cap, the inner surface of the outer shell being spaced from the outer surface of the head cap at an initial relative position prior to an impact, the outer shell being locally temporarily inwardly deformable at a point of impact and the outer shell also being globally movable both linearly and angularly relative to the head cap inner surface in response to an impact; and an elastic liner between and attached to both the head cap and the outer shell, the liner and the head cap establishing the initial relative position between the inner surface of the outer shell and the outer surface of the head cap prior to an impact, the liner being comprised of at least 275 generally radially oriented slender individual and independent columns made of a flexible foam and having an average slenderness ratio between 3 and 30, each foam column having a top surface attached directly to the outer shell, a bottom surface attached directly to the head cap and side surfaces extending between the outer shell and head cap, the foam columns and their top and bottom surface attachments in aggregate having sufficient cross-section and strength to sustain a 600 pound tensile force between the outer shell and the head cap without damage to a foam column or its attachment, and where in a pre-impact position the side surfaces of at least a portion of the foam columns are positioned in direct contacting slidable engagement with the side surfaces of at least two other foam columns and remain positioned in direct contacting slidable engagement in an impact position. |
