| 摘要 |
A gas mask comprises an outer full mask and an inner half mask for closed cycle respirators leaving an interspace between the half mask and the full mask. The outer mask is sealed around the person's face by one or more sealing frames and the inner mask is sealed with the face around the wearer's nose and mouth. The construction includes a passage between the half mask and a full mask with a check valve which opens with exhalation resistance in a direction toward the space between the full mask and the half mask. The outer full mask has a wall with a linkage compensation device which is closed by a cover and includes a bellows which expands and contracts in the device in accordance with variations in pressure within the interspace between the two masks. A spring is employed to bias the bellows into one of an expanded or contracted situation so that the bellows may either expand or contract against the spring pressure during operation and provide a leakage compensation in the space between the masks. |
