Fresh air breathing appts. - has face mask with filter connected to bellows with non-return valve, tubed to inlet bushing in external wall

摘要

The fresh air breathing apparatus (10) is particularly intended for use in a stuffy enclosed space. It comprises a face or nose mask with a filter insert and a narrow hose connecting the insert to a bellows with a non-return valve. A further hose connects this valve to an inlet bushing provided in a bore in an outside wall. The bushing may contain a filter. The narrow hose pref. has a diameter of approximately 7cm, whilst that of the bushing connecintg hose is about 25 cm.