DUST-AND-GAS PROTECTIVE CARTRIDGE Russian patent published in 1999 - IPC

FIELD: equipment for protecting respiratory organs under hazardous working conditions and for cleaning air in survival and ventilation systems. SUBSTANCE: cartridge has casing with burden placed between upper and lower grids, and projection extending along perimeter of casing. Shape of projection is similar to that of step on inner surfaces of lugs, which are distributed along perimeter of casing and of upper burden supporting grid. Replaceable filter is positioned in casing. Lugs of casing are positioned in alternation with lugs of upper grid. EFFECT: increased efficiency by reliable fastening of grids and simplified replacement of used filter. 6 dwg