US Patent 7735157 Full-face-type helmet

A full-face-type helmet such as an off-road driving helmet, in which ventilation of the interior of the full-face-type helmet is performed well by external air flowing in from a chin region, and a ventilation through hole extending through an impact absorbing liner substantially in the direction of its thickness need not be particularly formed in a region including the side head region and its vicinity of the impact absorbing liner for the external air flowing in from the chin region. The impact-on-the-chin absorbing portion of the impact absorbing liner disposed inside an outer shell having a first ventilation opening in the chin region includes a liner main body portion, and a sheet-like backing plate which is arranged on the inner surface of the liner main body portion. The liner main body portion includes a second ventilation opening substantially opposing the first ventilation opening, and a ventilation ridge groove which is formed in the inner surface of the liner main body portion and communicates with the second ventilation opening.