Abstract: A system to monitor the status of a firefighter comprising a self contained breathing apparatus associated with the firefighter and operational with a microprocessor to transmit and receive signals by means of transceivers, a monitor to visually observe the signals, and a personal alert safety system operational with the apparatus to detect firefighter distress signals.

Abstract: There is described a demand valve for a breathing apparatus with a “first breath” mechanism, wherein a demand valve is held closed by resiliently latching an operating diaphragm of the valve in a position wherein the valve is closed. The diaphragm is resiliently biased towards opening the valve, and the resilient latch is arranged to exert sufficient force so as not to be overcome by the resilient bias alone, but so as to be overcome by the combination of the resilient bias and a predetermined pressure difference across the diaphragm caused by sub-ambient pressure within the facepiece of the breathing apparatus.

Abstract: There is described a demand valve for a breathing apparatus wherein a pilot jet of the demand valve is controlled by a pivoting lever resiliently held against a planar face in which the pilot jet is formed. The pilot jet is preferably formed in a land surface surrounded by a recessed area of the planar face, and opening of the pilot jet is effected by movement of a control projection mounted on the pivoting lever. The area of the control projection is preferably greater than the area of the land surface.

Abstract: A face mask for a self contained breathing apparatus has two pairs of straps fixed to the frame of the mask, the straps being fixed to a net or woven head piece. The straps at the top of the head piece are fixed with respect to the mask, and the bottom straps are adjustable to tighten the mask against the face of the user. The nose cup has ribs that receive legs of a mounting member for eyeglasses. The eyeglasses include frames, with support arms that are slidably fixable to the mounting member. The mounting member moves towards and away from the eyes of the user, and the support arms move up and down with respect to the nose cup, for full adjustability of the eyeglasses. The nose cup of the face mask is adjustable by either removing a portion at the chin and shortening the mask, or simply removing the portion to allow the user's chin to extend beyond the nose cup while still inside the face seal.

Abstract: A backframe for a self contained breathing apparatus (SCBA) is formed of a molded shell having some depth, and a closure plate fixed to the shell to provide an enclosed volume. The molded shell with the closure plate yields a good weight-to-strength ratio, and provides a water- and dust-resistant enclosure for control components of the SCBA. A water-tight battery compartment is enclosed within the shell so the batteries are separated from other components. A low air pressure alarm provides an auditory signal, and may also include a tactile signal. A buddy breathing hose can be pulled from the backframe to provide a reasonable length tether; and, by connecting two such buddy breathing hoses, twice the length is provided.

Abstract: A self contained breathing apparatus has a display of air pressure within the face mask in the field of vision of the user of the breathing apparatus. The display is four lights that indicate the four quarter-tanks of pressure, and the lights change to indicate the amount of air remaining. A transducer receives tank pressure and provides an electric signal. The air pressure is placed on a bourdon tube which rotates a disk in response to changes in pressure. One half of the disk includes a gradient, and a light source emits light through the gradient to be received by a light sensor. As the disk rotates, the gradient varies the amount of light received by the sensor, so the electrical output of the sensor varies.

Abstract: A breathing apparatus comprises a supply of breathable gas and a facepiece by which breathable gas is supplied to a wearer, the facepiece including a supply valve for delivering gas to the interior of the facepiece, and an exhaust opening closeable by an exhaust valve for allowing the egress of exhaled gas from the facepiece. The exhaust valve comprises a movable valve member which, in a first position, closes the exhaust opening in the facepiece, in a second position is displaced toward the interior of the facepiece relative to the first position while still in sealing engagement with the exhaust opening to open the supply of breathable gas, and in a third position is displaced outwardly of the facepiece relative to the first position to open the exhaust opening to allow the egress of exhaled gas. The valve member is biased towards the second position by a single significant biasing means. A sealing element is preferably interposed between the valve member and the exhaust opening.

Abstract: Light is directed towards at least one eye of a user of a personal alert safety system (PASS), and the reflected light is sensed. When the eye blinks, there is an interruption of the reflected light signal indicating that the user is conscious. Electronic circuitry converts the variation in reflected light intensity into a corresponding variation in electrical signal. The PASS interprets this variable electrical signal as a reset indicator, so that as long as the wearer is conscious, the audio warning alarm in the PASS does not sound. The light is provided by a light emitting diode in the near infrared range, and the reflected beam may be sensed by a photodiode or phototransistor. Alternatively, ultra sound, or other light frequencies, may be used.

Abstract: A holder for a personal alert safety system (PASS) has a bracket to receive the PASS, and a housing connected to the bracket. An additional activation switch is installed in the PASS, the additional switch being magnetically operable. The housing is connected to the air line of a self contained breathing apparatus (SCBA). A piston or diaphragm is urged in one direction by air pressure, and is urged in the opposite direction by a spring in the absence of air under pressure. When the piston is moved in the one direction, a magnet is disposed adjacent to the additional switch, and when the piston is moved in the opposite direction by the spring, the magnet is removed from adjacent to the additional switch so the PASS is automatically activated by the presence of air pressure in an activated SCBA. The PASS can be used without the SCBA and can be activated manually as is conventional, either attached to or removed from the SCBA.

Abstract: A self contained braathing apparatus (SCBA) has a fill valve for filling the air tank while a user is wearing the SCBA. An SCBA conventionally has a pressure gauge or other apparatus on a hose that extends around generally to the front of the user, and this apparatus is provided with a quick disconnect valve as a tank fill valve. Such appratus must include a flow limiting orifice, and the present invention includes a check valve in parallel with the orifice so a substantial air flow can be obtained in one direction while the flow in the opposite direction is limited to the safety-mandated small flow.