Improved plant for supplying dustfree air to miners working in a dusty atmosphere

摘要

528,348. Ventilating mines. DEHASSE, L. May 4, 1939, No. 13373. Convention date, Feb. 10. [Class 137] A mine ventilation system comprises a flexible conduit c fitted with fans e to suck air through a filter f, and deliver it through nipples d into branch tubes g opening into masks h carried by the workmen. The nipples have pivoted stoppers i for use when a tube g is disconnected ; the masks consist of face screens with side openings and with pads to fit under the eyes.