EYEGLASS FRAME FOR RESPIRATORY MASKS

The respirator mask window assembly has marked curving. Its purpose is to ensure a tight fit of the window in its frame without additional stiffening devices. The face mask body has a moulded-on elastic bead of U-cross section accommodating the thickness of window sheet. The inner surfaces of the U-shape are provided with a continuous groove, which produces a suction action on the sheet when it is fitted. Alternatively the sucking action can be produced by suction cups evenly distributed along the inner surfaces of the bead. The frame with its U-cross section envelopes from the outside the bead and provides hermetic seal between window sheet and mask as well as additional stiffening.