Patent ID: 6029769
Filing Date: 2000-02-29
Classification: A42B,A61F,H04R

Abstract:
A wind noise reducing, partially permeable aerodynamic dam to be worn on a front helmet strap of a wearer's helmet assembly, the dam comprising:a base having a width parallel to said strap, a length perpendicular to said strap, an inner surface defined by said length and width, said surface having attachable means attached to said strap, the base having an outer surface;a matrix attached to said outer surface, the matrix having a height which is normal to said outer surface of base, the matrix having sufficient stiffness to support against wind pressure, the matrix also comprising a design shaped permeable structure;a group of filaments which are supported and attached to said matrix to at least within the confines of said matrix, the attached fiber forming a design shaped filter having at least said height and width, the filter having a thickness in the direction of said length, said thickness shaped according to a predetermined design;whereby said filter causes a tortuous path impedance to an incoming wind generally parallel to said length, resulting in a three dimensional flow velocity profile which provides a quiet retrolaminar wake past the wearer's ear canal.