| 摘要 |
Breathing equipment of the kind which includes a breathing hood (1) intended to surround the wearer's head (2), an inner mask (3) which covers at least the wearer's mouth and nose and a breathing gas delivery conduit (4). The equipment also includes means (6, 7) which permit gas to pass from the hood (1) to the mask (3), and check valve means (5) for passing gas from the mask (3) to the surroundings when the overpressure in the mask has reached a given value. The equipment is characterized by the combination of that the breathing gas is delivered to the hood (1) and that the means (6, 7) allow gas to pass in both directions between the hood (1) and the mask (3). The means (6, 7) therewith require a lower overpressure in the mask (3) for passage of gas from the mask to the hood than the pressure required by the check valve (5) to allow gas to pass to the surroundings.
|
