Protective respiratory helmet

摘要

This invention relates to protective respiratory helmets suitable for use in a polluted atmosphere. The helmet comprises a head cover 11 which is secured to the head of the wearer by an internal head band and harness 12. A visor 16 is pivotally mounted on the cover 11 by bearings 17. The visor 16 is provided with a sealing member 22 and a pair of one-way valve flap valves 27 to allow air to leave the visor. Filtered air is supplied to the visor via a duct 28 fitted to the inside of the head cover 11. A forehead seal is provided around the inside of the front of the cover comprising a block of foamed plastic or rubber 13 with an internal flap 14. A motor and fan 34 draws ambient air into the duct 28 through filter pads 41 and 42 located in a removable plastics filter cover 43.