| 摘要 |
An arrangement in protective masks comprising a face enclosing part with an opening (2) covered with a transparent material, a nosepiece (8) enclosing the wearer's mouth and nose, connections (3, 5) for means supplying clean air and for evacuation means, seal means (13, 15) engaging the wearer's head, and securing means engaging the back of the wearer's head. The protective mask comprises a rigid material helmet-like shell enclosing the front half of the wearer's head, having at its upper front portion said opening (2) and at its lower front portion the nosepiece (8), wherein the securing means comprise an arc-shaped securing flap (10) pivotably mounted on the upper rear portion of said shell (1), allowing the shell to be slipped on or off, and an arcuate visor-like clamping member (11) mounted at the back of the helmet-like shell securing for locking said flap. |
