3m Innovative Properties Company

David L Ausen

Paul A Martinson

Garry J Walker

Benjamin A Johnson

David J Schmidt

Air supply attachment for a helmet

Air filtering devices may be helmet-mounted or belt-mounted. The air filtering devices include a filtering device shell and a filtering unit. The filtering unit includes a contaminated-air inlet, a filter assembly in fluid communication with the contaminated-air inlet, a blower assembly in fluid communication with the filter assembly via a duct, and containing a filtered-air outlet, and a filtered-air passageway in fluid communication with the blower assembly outlet and leading to breathing headgear. The blower assembly is vibrationally isolated from the filtering device shell by being only attached to the filtering device shell by the duct. The duct includes an elastomeric material.

Air filtration device

A powered air purifying respirator (PAPR) includes a radial blower. The radial blower includes at least an impeller and a scroll having an upper outer surface and a lower outer surface. In one embodiment, a cross section of an air passageway of the scroll includes sides corresponding to the upper outer surface and the lower outer surface, the sides having parallel slanted segments. In another embodiment, the sides may be substantially parallel and may be curved. In yet another embodiment an upper outer surface of the scroll is concave and a lower outer surface of the scroll is convex. In that embodiment, the PAPR further includes an inlet, and the inlet is disposed at the lower outer surface.

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Eagan, MN, United States of America

David L Ausen