GB823887A - Improvements in respirator - Google Patents

Abstract

823,887. Respiratory appliances. ELECTRIC STORAGE BATTERY CO. June 6, 1957, No. 18087/57. Class 81 (2). A respirator mask comprises a unitary face piece 1 and a triangular filter box 2, integrally moulded from flexible material, and a filter supporting frame 14 and filter pad 16, the filter box 2 having an open base which is stretched for insertion of the frame 14 and filter 16. A face mask 1 of rubber or synthetic plastic is in one piece with a filter box 2 which is open at the base, an inhalation valve 8 being located in a wall dividing the filter box 2 from the face piece 1. The base wall la of the face piece has two exhalation valves. A dust filter 16, e.g. of felt, is supported on a synthetic plastic frame 14 which has a downwardly extending gripping piece 15. The frame 14 and the filter 16 are inserted in the filter box 2 and are held in position by inwardly extending lugs at the base of the filter box 2. Ribs 17 extending inwardly from the edges of the filter box 2 prevent air leakage past the filter 16 and space the filter 16 from the side walls of the filter box 2. Yieldable accordion pleats 7 in the nose covering portion of the face piece 1 enables the face piece 1 to fit faces of different contours. The head strap is looped round flexible rubber straps attached by rivets 5 on each side of the face piece, the arrangement being such that the head strap can be worn high or low on the head. Alternatively the head strap is secured to the face piece by snap fasteners so arranged that the pull of the head strap rocks the rearward parts of the fasteners towards the wearer's cheeks thus pushing the facepiece against the cheeks.