Abstract: Secondary energy absorbing helmet underwear is to be worn by a user under a primary rigid hard hat, sports helmet or military helmet. The helmet underwear includes an integral self elasticized stretchable material that includes a three-dimensional structure that is generally of semi-spherical shape to fit about the users head and that includes an optional peripheral stretchable stretch band that provides a means for retaining the helmet underwear in place on the users head. The stretchable material and core includes front and rear layers that are each formed as a knitted layer and interconnecting yarns that interconnect between the front and rear layers and define a predetermined spacing between the front and rear layers. The interconnecting yarns, in combination with the layers provide a safety barrier between the rigid hat and the user's head.

Abstract: Secondary energy absorbing helmet underwear is to be worn by a user under a primary rigid hard hat, sports helmet or military helmet. The helmet underwear includes an integral self elasticized stretchable material that includes a three-dimensional structure that is generally of semi-spherical shape to fit about the users head and that includes an optional peripheral stretchable stretch band that provides a means for retaining the helmet underwear in place on the users head. The stretchable material and core includes front and rear layers that are each formed as a knitted layer and interconnecting yarns that interconnect between the front and rear layers and define a predetermined spacing between the front and rear layers. The interconnecting yarns, in combination with the layers provide a safety barrier between the rigid hat and the user's head.