| 摘要 |
PROBLEM TO BE SOLVED: To obtain a lightweight cushioning material for a helmet, having moderate cooling and ventilating effects and excellent in shock absorbing properties by forming a cylindrical unit having a helical structure while curving a thin plate material in the plane direction and forming a honeycombed structural unit under specific conditions. SOLUTION: This helmet is obtained by forming a cylindrical unit 16 having a helical structure while curving thin plate materials 14 formed into a slender belt shape in the plane direction, securing the thin plate materials 14 so as to be mutually adjacent in the partial peripheral parts in the longitudinal direction of the cylindrical unit 16 at plural sites 18 in the curve direction thereof, then cutting out the partial peripheral part from the cylindrical unit 16 and developing the whole so as to mutually separate the respective thin plate materials 14 in the unsecured part and thereby forming a honeycombed structural unit having a three-dimensional curved surface along the inner surface of an outer shell hat body. The resultant cushioning material is used as a part or all of the inner covering unit of the helmet provided with the inner covering unit on the inner surface of the outer shell hat body. |
