Patent ID: 6920880

Claim:
A mask defogging system for purging air in the goggle area on the interior of a face mask, comprising: a mouthpiece having an airway therethrough, a mount adapted for supporting the mouthpiece in a service position immediately in front of the mouth of a person wearing the face mask such that the person can selectively engage the mouthpiece airway by puckering the person's lips thereagainst while not requiring support or retention of the mouthpiece manually or with the lips or teeth, an air flow channel which includes the airway in the mouthpiece, and which is connected to the goggle area on the interior of the face mask to provide for purging air therefrom, and an air flow control associated with the air flow channel to assure positive purging of air in the goggle area on the interior of the face mask by permitting air to flow through the air flow channel to the mouthpiece airway from the goggle area on the interior of the face mask while substantially preventing air flow in the opposite direction to the goggle area, to provide affirmative, breath-driven, passive ventilation for the goggle area on the interior of the face mask while permitting a person wearing the mask to breathe freely and without distraction, obstruction, or deliberate action, by normal breathing with the lips in a natural position just behind the mouthpiece, and to permit the person selectively to force increased ventilation for the goggle area by puckering the person's lips to engage the mouthpiece.