GB591531A - Improvements in respirator masks, especially oxygen masks for aircrews - Google Patents

Abstract

591,531. Respirator masks. GILSON, J. C. Aug. 13, 1945, No. 20720. [Class 81 (ii)] A respirator mask, Fig. 3, comprises a face piece 15 of rubber &c. having therein a gas duct 12a comprising a resilient rib spaced from the edge and extending across the bottom and up the sides of the face piece and inwardly towards the nose part below the eyes to form an abutment limiting the entry of the chin, cheeks and nose, the arrangement being such that the inner surface of the face piece in front of the rib is kept out of contact with, and condensed moisture can drain away from, the wearer's face. Gas enters through inlet fitting 21 and passes into the face piece through openings 14 above the level of the wearer's mouth. An expiratory valve body 23 having a rubber mushroom type valve is mounted in a housing 18 formed with a shield 33, and a microphone 29 in a boss 28 using a clamping ring 30. An inspiratory valve 31 (or blanking plate) is also provided. Fig. 1 shows the harness comprising two straps 37, 38 fitted with a press stud member 39 engageable with the wearer's helmet &c. The upper strap 37 is attached to the microphone clamping ring 30 and the lower 38 to a ring 46 of similar material bound tightly around the valve housing 18. Strap 37 is also held close to the face piece by a wire bridge held by a pair of moulded lugs. The right hand strap 43 provided with stirrup 44 adapted to engage a hook on the helmet is carried by a loop 47 fixed to rings 30, 46. A nose pinch clip of soft wire passing through moulded lugs holds the face piece to the nose. The gas feed tube 22 is provided with a bayonet socket and swivelling spring clip 36. Fig. 5 shows a modification where in the mask is suspended by two straps 43, 60 connected by triangular shackles to upper and lower supporting straps 56, 58. The ends of the latter are secured to the inlet fitting 20. Two expiratory valves are used, and the microphone boss 28 is set in to the face piece. The boss and an extension 53 thereof are slit at 54 whereby the microphone and its leads may be removed. The gas ducts, Fig. 8, terminate in a web 51, and there is provided a moulded flap 52 lined with, for example, suede leather 32. The mask is more particularly for air crews, for use, for example, in conjunction with the device of Specification 591,530, or for, e.g., mine rescue work, or for administering anaesthetics.