Patent ID: 7210174

Claim:
A crash helmet, comprising a helmet body, a face mask, and a binding device for attaching the face mask to the helmet body, wherein the helmet body has two opposite sides each formed with a mounting cavity; the face mask has two opposite sides each having an inner face provided with a protruding ring having a periphery formed with two arc-shaped protruding blocks, and a gap is defined between each of the two protruding blocks and the inner face of the face mask; the binding device is mounted in the mounting cavity of the helmet body and includes a fixed board and a movable board; the fixed board is formed with a through hole and provided with an elastic positioning arm having an outward extending protruding positioning block; the movable board has a first face formed with a circular protruding plate received in the through hole of the fixed board; the movable board has a second face formed with a circular receiving recess having a periphery formed with two opposite arc-shaped receiving grooves and two opposite arc-shaped catch plates; the protruding ring of the face mask is received in the receiving recess of the movable board, and the two protruding blocks of the face mask are extended through the two receiving grooves of the movable board; each of the two catch plates of the movable board is locked in the gap of the respective protruding block of the face mask by rotation of the movable board; the movable board has a side provided with a frame having a side formed with a locking slot lockable on the positioning block of the fixed board by rotation of the movable board.