Patent ID: 8365771
Filing Date: 2013-02-05
Classification: A62B,Y10T

Abstract:
1. A unidirectional valve for use with a filtering face mask, the unidirectional valve positioned to provide fluid communication between a first gas space and a second gas space, the unidirectional valve comprising: a valve seat comprising a seal surface and an aperture positioned to provide fluid communication between the first gas space and the second gas space; and a flap, the flap being flexible and coupled to the valve seat such that the flap makes contact with the seal surface when the flap is in a closed position and such that the flap can flex away from the seal surface to an open position, wherein the first gas space and the second gas space are not in fluid communication via the aperture when the flap is in the closed position, and wherein the first gas space and the second gas space are in fluid communication via the aperture when the flap is in the open position, the flap having a fixed end and a free end; a housing positioned to at least partially cover the valve seat and the flap, wherein the housing has a front and a rear, the front of the housing being proximate the free end of the flap and the rear of the housing being proximate the fixed end of the flap; and a projection coupled to an inner surface of the housing and positioned to project inwardly from the inner surface, the projection having a height, the height generally decreasing toward the front of the housing.