A respirator 10 that has a mask body 12 and a harness 16 has an exhalation valve 23 that includes a valve seat 36 and a flexible flap 42. The valve seat 36 has an orifice 38 and has a noncircular seal surface 40 surrounding the orifice 38. The flexible flap 42 is secured to the valve seat 36 at a centroid of the orifice and has a variable stiffness structure. The variable stiffness structure allows the flap to equally deflect under a given load at different distances from the centroid at the noncircular seal surface. An exhalation valve having this construction may beneficially optimize pressure drop and overall valve performance for applications where valve space may be limited.

A respirator 10 that has a mask body 12 and a harness 16 has an exhalation valve 23 that includes a valve seat 36 and a flexible flap 42. The valve seat 36 has an orifice 38 and has a noncircular seal surface 40 surrounding the orifice 38. The flexible flap 42 is secured to the valve seat 36 at a centroid of the orifice and has a variable stiffness structure. The variable stiffness structure allows the flap to equally deflect under a given load at different distances from the centroid at the noncircular seal surface. An exhalation valve having this construction may beneficially optimize pressure drop and overall valve performance for applications where valve space may be limited.

A facemask includes integrated actuating modules having sensors and other mechanisms. The facemask has one or more sockets into which various modules may be inserted. The facemask itself or the modules may include air filters and check valves to regulate airflow along or through the various modules. The modules may detect various substances either in the ambient air or the air exhaled by the wearer. The facemask also includes modules for measuring pulmonary and/or cardiovascular exertion, lung capacity and other physiological metrics. Other modules may provide supplements, vitamins or other substances such as tobacco smoke or vapor from vaporizers to the wearer. The modules may include microcontrollers in wireless communication with software applications on electronic devices so that the facemask may also serve as a cellular phone.

A facemask includes integrated actuating modules having sensors and other mechanisms. The facemask has one or more sockets into which various modules may be inserted. The facemask itself or the modules may include air filters and check valves to regulate airflow along or through the various modules. The modules may detect various substances either in the ambient air or the air exhaled by the wearer. The facemask also includes modules for measuring pulmonary and/or cardiovascular exertion, lung capacity and other physiological metrics. Other modules may provide supplements, vitamins or other substances such as tobacco smoke or vapor from vaporizers to the wearer. The modules may include microcontrollers in wireless communication with software applications on electronic devices so that the facemask may also serve as a cellular phone.

A handheld device for treating air to a user includes an airflow path having an illumination chamber with a reflective surface, wherein the reflective surface is sufficiently reflective and configured to impart multiple reflections of at least a portion of the light introduced into the illumination chamber. The introduced light is produced by an onboard UV light generator, wherein the UV light generator can be cycled corresponding to at least one of a pressure and an airflow in the airflow path.

A handheld device for treating air to a user includes an airflow path having an illumination chamber with a reflective surface, wherein the reflective surface is sufficiently reflective and configured to impart multiple reflections of at least a portion of the light introduced into the illumination chamber. The introduced light is produced by an onboard UV light generator, wherein the UV light generator can be cycled corresponding to at least one of a pressure and an airflow in the airflow path.

A bypass knob for a pressure regulator configured for use with a facemask of a breathing apparatus has a first member having a first engagement surface and a second member having a second engagement surface positioned opposite the first engagement surface. At least one slot is formed on the first engagement surface and at least one deflectable beam having a latch is formed on the second engagement surface of the second member. When the first member is rotated in a first direction about the longitudinal axis via a first rotational torque, the latch of the at least one deflectable beam is engaged with the at least one slot to rotate the second member with the first member, and disengaged when the first member is rotated in the first direction via a second rotational torque higher than the first rotational torque.

A bypass knob for a pressure regulator configured for use with a facemask of a breathing apparatus has a first member having a first engagement surface and a second member having a second engagement surface positioned opposite the first engagement surface. At least one slot is formed on the first engagement surface and at least one deflectable beam having a latch is formed on the second engagement surface of the second member. When the first member is rotated in a first direction about the longitudinal axis via a first rotational torque, the latch of the at least one deflectable beam is engaged with the at least one slot to rotate the second member with the first member, and disengaged when the first member is rotated in the first direction via a second rotational torque higher than the first rotational torque.

A face shield adapted to fit over a face of a user to cover a nose and mouth of the user. The face shield includes an exhale port, an attachment system to fasten the shield to the user, a fan insert receiver, and an air inlet opening connected to the fan insert receiver. A fan that attaches to the fan insert receiver. The fan includes a motor, fan blades attached to the motor and an air exit. The air exit of the fan is positioned to dump air from the air inlet opening into the area covered by the shield. An air filter is connected to the air inlet opening of the shield. An exhale valve is connected to the exhale port that allows waste air to exit the shield. There is a power source connected to the fan motor to run the fan.

A face shield adapted to fit over a face of a user to cover a nose and mouth of the user. The face shield includes an exhale port, an attachment system to fasten the shield to the user, a fan insert receiver, and an air inlet opening connected to the fan insert receiver. A fan that attaches to the fan insert receiver. The fan includes a motor, fan blades attached to the motor and an air exit. The air exit of the fan is positioned to dump air from the air inlet opening into the area covered by the shield. An air filter is connected to the air inlet opening of the shield. An exhale valve is connected to the exhale port that allows waste air to exit the shield. There is a power source connected to the fan motor to run the fan.