主权项 |
1. A head-protector which comprises:
a shell dimensioned to fit on the head of a user, wherein the shell is formed with an opening defining a periphery; a lens dimensioned to cover the opening of the shell, wherein the lens has an edge and is made of a transparent material; a locking mechanism for supporting the lens on the shell, wherein the locking mechanism is selectively activated to alternatively hold the lens in a stowed position wherein the lens is oriented on the shell to uncover the opening, and in an operational position wherein the lens is oriented over the opening and is configured to establish a first vent extending across the forehead of the user between the edge of the lens and the shell and is configured to establish a second vent extending across the chin of the user between the edge of the lens and the shell to provide for laminar flow of air over the lens between the first vent and the second vent; a band dimensioned to surround the opening of the shell and to cause a snug fit with the shell, along the periphery of the opening, when the lens is in its operational position; and a plurality of posts interconnecting the band with the lens at points adjacent the edge of the lens to establish a distance “d” between the band and the edge of the lens to establish the first vent and the second vent, wherein the band is engaged with the locking mechanism for movement of the band with the lens during a rotation of the lens between the stowed position and the operational position. |