| 摘要 |
Breathing equipment including a breathing mask, breathing hood (1) or the like, and a conduit (2) through which breathing gas is delivered to the mask or hood. The equipment also includes a valve means (4) which is normally closed in use and which when open connects the space in the mask or hood (1) with the surrounding atmosphere so that said atmosphere can be breathed. To this end, means (8, 11) are provided for detecting when the supply of breathing gas to the mask or the hood (1) has fallen beneath a given level and therewith open the valve means. The valve means (4) is suitably a pressure-controlled arrangement which opens when the pressure in the breathing gas conduit (2) has fallen beneath a predetermined value. |
