| 主权项 |
1. A protective helmet for repetitive impact applications, the helmet comprising:
a hard impact-resistant outer shell having an inner surface, a head-follower head cap located within the outer shell, the head cap being of similar shape to the outer shell adapted to surround at least a portion of a cranial part of a wearer's head and having an outer surface facing the inner surface of the outer shell, the inner surface of the outer shell being spaced from the outer surface of the head cap, an adjustable chin strap assembly having an attachment/detachment device for securing said adjustable chin strap assembly to the head cap, enabling said wearer to secure and unsecure the helmet to said wearer's head, a liner between the head cap and outer shell, said liner exhibiting energy absorbing linear compliance and energy absorbing angular compliance, the liner being comprised of a plurality of side-by-side, radially-oriented, elastically compliant foam columns, each column of said plurality of columns comprising a bottom surface directly adhered to the outer surface of the head cap and each column of said plurality of columns comprising a top surface directly adhered to the inner surface of the outer shell, said plurality of columns filling a space between the head cap and outer shell and each column of said plurality of columns comprising a side surface in direct slidable contact with a side surface of an adjacent column, said protective helmet having an initial pre-impact position, a centered impact position, and an off-centered impact position, said initial pre-impact position comprising the radially oriented columns being in an unbent condition, a first point on the head cap outer surface is aligned with a corresponding first point on the outer shell inner surface, a second point on the head cap outer surface is aligned with a corresponding second point on the outer shell inner surface, a third point on the head cap outer surface is aligned with a corresponding third point on the outer shell inner surface, and a fourth point on the head cap outer surface is aligned with a corresponding fourth point on the outer shell inner surface, said centered impact position comprising both said outer shell and said head cap moved away from said initial pre-impact position, the columns between said third point on the head cap and the fourth point on the head cap are compressed, the columns between the first point on the head cap and the second point on the head cap are stretched, the columns between the second point on the head cap and the third point on the head cap are deformed into S curves, and the columns between the fourth point on the head cap and the first point on the head cap are deformed into S curves, with said first and second points on the outer shell inner surface displaced with respect to said first and second points on the head cap outer surface and said third and fourth points on the outer shell inner surface displaced with respect to said third and fourth points on the head cap outer surface, the top surfaces of each of the foam columns between the first and second points on the outer shell inner surface displaced with respect to the bottom surfaces of each of the foam columns between the first and second points on the head cap outer surface portion, each of the foam columns between the second and third points and each of the foam columns between the first and fourth points being bent and in an S curve, adjacent foam columns of the plurality of columns in an S curve, said off-centered impact position comprising both said outer shell and said head cap are moved away from both said initial pre-impact position and said centered impact position, the outer shell inner surface transversely displaced with respect to the head cap outer surface in a plane extending through first, second, third and fourth points on the head cap outer surface, the foam columns between the third and fourth points on the head cap are compressed, the foam columns between the first and second points are stretched, and all of the foam columns of the plurality of foam columns are deformed into S curves, with the foam columns therein being bent and in an S curve, and after an impact the elastic foam columns collectively contribute to the liner automatically returning the outer shell to said pre-impact position with the head cap. |
