Patent ID: 6892400

Claim:
A helmet having an opening type chin protection bar, comprising: a helmet body having a face protection opening in a front side; a chin protection bar designed to protect a user's chin by blocking a part of the opening of the helmet body; a shield for shielding the remaining portions of the opening on an upper side of the chin protection bar; a hinge mechanism engaged to be rotatable in the upper and lower directions by engaging the chin protection bar to the left and right sides of the helmet body and not exposed to the outside by inserting a hinge bolt in a direction from the inner side of the helmet body to the outer side; and a locking mechanism designed to rotate the chin protection bar in the upper and lower directions with respect to the hinge bolt of the hinge mechanism as a shaft wherein the chin protection bar is locked in a lowered state, and is unlocked for its lifting operation, said hinge mechanism including: a female screw symmetrically attached to left and right inner sides of the chin protection bar wherein the female screw is engaged and embedded; an engaging plate having a guide rib provided in a surrounding portion of the female screw; and a hinge bolt engaged with the female screw and having a spacer.