Gas mask accessory - has valve shutting off connection from inside to outside and allowing food supply

摘要

The gas mask accessory forms a connection between the interior of the mask and the outside. A valve shuts off the connection in a first position and frees it in the second so as to allow the supply of food or the discharge of transpiration moisture, and means are provided for holding it in the first position. The valve can be in the form of a plate working in a passage, and containing an aperture, so that in the second position the passage is free.