GB872634A - Face mask - Google Patents

Abstract

872,634. Respiratory masks. RUSSELL, A. M. Aug. 8, 1957 [Aug. 21, 1956], No. 25077/57. Class 81 (2). A respiratory mask comprises a face-piece made of soft pliable material for covering the nose and mouth, and includes malleable wire stiffening loops 11, 12 embedded near the upper edge and across the lower part, respectively, exhalation and inhalation turrets 13, 14, 15 each with an opening, a valve 26 in at least one turret opening and means 40 removably mounted on one turret to provide a preselected resistance to exhalation. The mask 10 which is made of latex rubber has a peripheral faceengaging flange 20. The turrets 13, 14, 15 are integral with the mask and have apertured valve bodies 23 which are resilient but stiffer than the mask. Two turrets 13, 14 have inhalation valve flaps 26 and the third turret 15 has an exhalation valve flap. A deflector (not shown) is fitted over the upper part of the exhalation turret. An inflatable bag 30 with an arched neck 31 is releasably connected over one inhalation turret 14 and either is used as a rebreathing bag or is supplied with oxygen for use as a reservoir. Predetermined positive pressures are maintained in the mask during exhalation by a housing 41 mounted over the exhalation turret 15 and having an aperture which is restricted by one of a series of graduated holes in a disc 44 rotatable on the housing. An opening in the mask normally closed by a stud 49 permits connection of the mask interior with a water manometer or admission of a duodenal drainage tube. The mask is secured on the weaver by latex rubber straps 22 having holes which engage over studs 21 at the edge of the mask. When the bag 30 is used as a rebreathing bag, the valve 26 in the turret to which the bag is connected may be removed.