Abstract: A filtering face mask that has a mask body and an exhalation valve. The mask body is adapted to fit over the nose and mouth of a wearer. The exhalation valve is attached to the mask body and includes a valve seat that comprises a seal surface, an orifice that is circumscribed by the seal surface, a flap-retaining surface, and a single flexible flap that has a fixed portion and a free portion and first and second opposing ends. The first end of the single flexible flap is associated with the fixed portion of the flap so as to remain at rest during an exhalation, and the second end is associated with the free portion of the flexible flap so as to be lifted away from the seal surface during an exhalation. The second end also is located below the first end when the filtering face mask is worn on a person. The flexible flap is positioned on the valve seat such that the flap is pressed towards the seal surface in an abutting relationship therewith when a fluid is not passing through the orifice.

Abstract: A filtering face mask that has a mask body and an exhalation valve. The mask body is adapted to fit over the nose and mouth of a wearer. The exhalation valve is positioned on the mask body substantially opposite to a wearer's mouth. The exhalation valve comprises a valve seat that has a seal surface, an orifice that is circumscribed by the seal surface, and cross members that extend across the orifice to create a plurality of openings within the orifice. The valve also includes a single flexible flap that has a fixed portion and a free portion and first and second opposing ends. The first end of the single flexible flap is associated with the fixed portion of the flap so as to remain at rest during an exhalation, and the second end being associated with the free portion of the flexible flap so as to be lifted away from the seal surface during an exhalation. The second end also is located below the first end when the filtering face mask is worn on a person.

Abstract: A method of making a filtering face mask, which method includes the steps of: (a) providing (i) a valve seat that comprises an orifice and a seal surface, wherein the orifice allows air to pass therethrough and is surrounded by the seal surface, and (ii) a single flexible flap; (b) supporting the single flexible flap non-centrally and operatively relative to the orifice of the valve seat to form an exhalation valve, the single flexible flap being supported such that there is an imposed curved profile that extends from a first point where a stationary portion of the flap is supported on the valve seat to a second point where a free portion of the flap contacts a seal surface; and (c) attaching the exhalation valve to a mask body that is adapted to fit over the nose and mouth of a person.

Abstract: A filtering face mask that has a mask body and an exhalation valve. The mask body is adapted to fit over the nose and mouth of a wearer. The exhalation valve is attached to the mask body and has a valve seat that includes a seal surface and an orifice that is circumscribed by the seal surface. The valve also has a single flexible flap that has a fixed portion and a free portion and first and second opposing ends. The first end of the single flexible flap is associated with the fixed portion of the flap so as to remain at rest during an exhalation, and the second end is associated with the free portion of the flexible flap so as to be lifted away from the seal surface during an exhalation. The second end also is located below the first end when the filtering face mask is worn on a person. The flexible flap is positioned on the valve seat such that the flap is pressed towards the seal surface in an abutting relationship therewith when a fluid is not passing through the orifice.

Abstract: Filtering face mask 10 has a mask body 12 and an exhalation valve 14. The mask body 12 is adapted to fit over the nose and mouth of a person, and the exhalation valve 14 is attached to the mask body 12. The exhalation valve 14 has a valve seat 26 and a single flexible flap 24. The valve seat 26 includes a seal surface 31 and an orifice 32. The orifice 32 is circumscribed by the seal surface 31. The single flexible flap 24 has a fixed portion 28 and one free portion 38. The one free portion 38 has a free end, and the fixed portion 28 is located off-center of the flexible flap 24 away from the free end and is secured to the valve seat 26 outside the orifice 32. The one free portion 38 is pressed toward the seal surface 31 when the wearer is neither inhaling or exhaling. The free portion 38 can be lifted from the seal surface 31 during an exhalation.

Abstract: A filtering face mask that comprises a mask body that is adapted to fit over the nose and mouth of a wearer, the mask body comprising a filtration layer through which inhaled air may pass before being inhaled by a wearer of the face mask; and an exhalation valve that is attached to the mask body, the exhalation valve allowing air exhaled by a wearer to pass from an interior of the mask body to its exterior without having to pass through the filtration layer, the exhalation valve comprising: a valve seat that comprises: a seal surface; and an orifice that is circumscribed by the seal surface; and a single flexible flap that has one fixed portion and one free portion and a circumferential edge, the circumferential edge having a first segment that is associated with the one fixed portion of the flap so as to remain at rest during an exhalation and having a second segment that is associated with the one free portion of the flexible flap so as to be lifted away from the seal surface during an exhalation, the secon

Abstract: An exhalation valve 14 for a filtering face mask 10 has a flexible flap 24 that makes contact with a curved seal ridge 30 of a valve seat 26 when the valve 14 is in the closed position. The curvature of the seal ridge 30 corresponds to a deformation curve exhibited by the flexible flap 24 when secured as a cantilever at one end and exposed at its free portion to a uniform force and/or a force of at least the weight of the free portion of the flexible flap. A seal ridge curvature corresponding to a flexible flap exposed to uniform force allows the flexible flap 24 to exert a generally uniform pressure on the seal ridge to provide a good seal. A ridge curvature corresponding to a flexible flap exposed to a force of at least the weight of the flap's free portion allows the flexible flap 24 to be held in an abutting relationship to the seal ridge 30 under any static orientation by a minimum amount of force, thereby providing a face mask 10 with an extraordinary low pressure drop during an exhalation.

Abstract: A filtering face mask that comprises a mask body that is adapted to fit over the nose and mouth of a wearer, the mask body comprising a filtration layer through which inhaled air may pass before being inhaled by a wearer of the face mask; and an exhalation valve that is attached to the mask body, the exhalation valve allowing air exhaled by a wearer to pass from an interior of the mask body to its exterior without having to pass through the filtration layer, the exhalation valve comprising: a valve seat that comprises: a seal surface; and an orifice that is circumscribed by the seal surface; and a single flexible flap that has one fixed portion and one free portion and a circumferential edge, the circumferential edge having a first segment that is associated with the one fixed portion of the flap so as to remain at rest during an exhalation and having a second segment that is associated with the one free portion of the flexible flap so as to be lifted away from the seal surface during an exhalation, the secon

Abstract: A filtering face mask that comprises a mask body adapted to fit over the nose and mouth of a person; and an exhalation valve that is attached to the mask body. The exhalation valve comprises a valve seat and a flexible flap. The valve seat has an orifice through which fluid can pass and is surrounded by the seal surface. The flexible flap is operatively supported relative to the valve seat and pressed against the seal surface of the valve seat in a closed state of the exhalation valve. The flexible flap assumes in its closed state, a curved profile in a cross-sectional view thereof The curved profile comprises a curve that extends from a first point where a first portion of the flexible flap contacts the seal surface to a second point where a second portion of the flexible flap contacts the seal surface.

Abstract: A respirator 10 includes a compressible filter element 12, a filter element retainer 14, and a face piece 16. The respirator is unique in that the filter element 12 compresses when installed in the retainer 14, allowing a friction fit to be maintained between the filter element 12 and retainer 14. The friction fit enables the filter element 12 to be readily replaced when its service life has expired.

Abstract: A respirator 10 includes a compressible filter element 12, a filter element retainer 14, and a face piece 16. The respirator is unique in that the filter element 12 compresses when installed in the retainer 14, allowing a friction fit to be maintained between the filter element 12 and retainer 14. The friction fit enables the filter element 12 to be readily replaced when its service life has expired.

Abstract: A full face respirator mask (10) includes a face shield portion (12) with the seal (20) surrounding a lens portion (14). Inhalation ports (16) and an exhalation port (18) are formed at the lower portion of the lens (14). A center adapter (30) includes a nose cup (40) and an exhalation valve (38) in the center orifice (18). The inhalation ports (16,116) are placed at each side of the exhalation port (18) and include connector portions (50,150) formed with the lens (14) or ultrasonically welded to the lens (14). The connector portions (50) include male connectors (58) in a first embodiment and female connectors (150) in a second embodiment receiving complementary formed connectors of a breathable air source.

Abstract: An exhalation valve 14 for a filtering face mask 10 has a flexible flap 24 that makes contact with a curved seal ridge 30 of a valve seat 26 when the valve 14 is in the closed position. The curvature of the seal ridge 30 corresponds to a deformation curve exhibited by the flexible flap 24 when secured as a cantilever at one end and exposed at its free portion to a uniform force and/or a force of at least the weight of the free portion of the flexible flap. A seal ridge curvature corresponding to a flexible flap exposed to uniform force allows the flexible flap 24 to exert a generally uniform pressure on the seal ridge to provide a good seal. A seal ridge curvature corresponding to a flexible flap exposed to a force of at least the weight of the flap's free portion allows the flexible flap 24 to be held in an abutting relationship to the seal ridge 30 under any static orientation by a minimum amount of force, thereby providing a face mask 10 with an extraordinary low pressure drop during an exhalation.

Abstract: An exhalation valve 14 for a filtering face mask 10 has a flexible flap 24 that makes contact with a curved seal ridge 30 of a valve seat 26 when the valve 14 is in the closed position. The curvature of the seal ridge 30 corresponds to a deformation curve exhibited by the flexible flap 24 when secured as a cantilever at one end and exposed at its free portion to a uniform force and/or a force of at least the weight of the free portion of the flexible flap. A seal ridge curvature corresponding to a flexible flap exposed to uniform force allows the flexible flap 24 to exert a generally uniform pressure on the seal ridge to provide a good seal. A seal ridge curvature corresponding to a flexible flap exposed to a force of at least the weight of the flap's free portion allows the flexible flap 24 to be held in an abutting relationship to the seal ridge 30 under any static orientation by a minimum amount of force, thereby providing a face mask 10 with an extraordinary low pressure drop during an exhalation.

Abstract: A heat exchanger including a plate of heat conductive material having a first major face and second major face. An array of a plurality of integral heat transfer elements projecting from the first face and a fan to cause a flow of a heat transfer fluid past the heat transfer elements thereby transferring heat between the heat exchanger and the heat transfer fluid.