Patent ID: 7036507

Claim:
A filter mask comprising: filter material having an inner surface to be worn against a wearer's face, and an outer surface, said filter material comprising pleated means for folding and unfolding said filter material such that when folded said filter materials assumes an essentially flat storage configuration having upper, lower and side edges and such that when unfolded said filter material forms a mask adapted for placement on the wearer's head so as to cover the nose and mouth of the wearer, said pleated means comprising an omega pleat provided proximate to said upper edge in said essentially flat storage configuration and a secondary pleat provided between said omega pleat and said lower edge in said essentially flat storage configuration, said omega pleat providing a breathing chamber when unfolded, said secondary pleat providing a pocket adapted to fit over a chin of the wearer when unfolded, said secondary pleat comprises a first fold and a second fold; and means for securing said filter material to a head of the wearer.