Abstract: An automatic transfer regulator for automatically switching between a primary (hose line) breathing air source and a secondary source (escape cylinder). A pressure sensing system detects the line pressure of the primary source using a spring loaded poppet connected to one side of a transfer poppet valve, with the other side connected to the output of a reducer. The pressure sensing system is fed by the primary source through an orifice. When the sensor detects loss of hose line pressure, the system pressure is released to ambient. This bleeds the pressure from the system side of the transfer poppet valve, allowing the reducer output to force the poppet back, thus actuating the secondary source. A check valve prevents reducer output from escaping through the primary source inlet.

Abstract: A gas detection sensor system including active and reference elements (Rsense, Rref) are arranged in a modified bridge circuit (12, 14, 22, 24) which allows power (Vbat) to be supplied seperately to the active and reference element (Rsense, Rref). A digal processor (30) monitors the resistances of the elements (Rsense, Rref) to control a pulse-width modulator supplying power to the elements, thereby maintaining nearly constant temperatures in the sensor elements (Rsense, Rref) and to translate the decrease in power needed to maintain constant temperature on the catalytic element into an output proportional to the concentration of combutible gas in air. The system periodically measures the resistance of the elements (Rref, Rsense) and enables dual operating modes of catalytic-bead detector. One active or reference element (Rsense, Rref) can alternately measure low concentrations of combustible gases up to the lower explosive limit (LEL) or measure high concentrations, up to 100% by volume.

Abstract: A filter cartridge assembly including a replendam that combines a particulate filter with an irregular shaped gas sorbent bed. Best operational practice requires that the air passing through the filter be distributed uniformly over the sorbent bed. The repledam directs the air over the surface of the larger sorbent bed utilizing vane-like structures extending from the reticulated member providing for uniform distribution.

Abstract: A respiratory mask and service module combination for pressure breathing. The respiratory mask has a hardshell member that extends along the contour of the face toward the peripheral edge of the mask and has a central portion forming a canopy. An inhalation/exhalation valve assembly having two breathing conduits and integrally formed so as to provide communication between the conduits. The assembly mounts externally to the mask such that the valves are capable of being sealed along the outer surface of the respiratory mask. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to limit the scope or meaning of the claims. 37 C.F.R. 1.72(b).

Abstract: An overpack is provided for packaging cylinders containing compressed gas. Cylinders containing compressed gas typically have a pressure relief mechanism that releases the gas from the cylinder when the pressure inside the cylinder approaches a pressure detrimental to the cylinder. In high heat, high temperature situations such as when the overpack is exposed to a fire, the overpack of the present invention extends the time that it takes for the cylinders to trigger the pressure relief mechanism.

Abstract: A self contained breathing apparatus includes a pressure vessel which holds a supply of breathing air. The pressure vessel is in fluid communication through a first stage pressure regulator with a second stage breathing regulator. The breathing regulator is operatively connected to a user face mask. When the pressure available in the supply is at a suitable pressure, the pressure regulator provides pressure to breathing regulator at a first pressure. When the pressure in the supply falls to a value indicative of impending depletion of the air supply, a transfer piston in a step up vale shifts. A change in condition of the step up valve causes a step up piston to increase the output pressure from regulator. This increased pressure moves a sensing piston and causes indicating devices in an alarm circuit to be activated. In alternative embodiments, an electronic alarm module may be used.

Abstract: A face mask for covering the nose and mouth of the wearer for supplying breathing gas thereto and a pair of strapless goggles which are easily and quickly donnable. The goggles are detachably attachable to the face mask by a tongue-and-groove connection wherein the tongue of the goggles is snapped into the face mask groove. Buttons are provided at the groove entrance for locking the tongue in the groove, the goggles being removable by depressing the buttons and sliding the tongue out over the depressed buttons. A face mask strap is coupled with hooks on the goggles frame for holding the goggles sealingly against the wearer's face. A vent is provided for supplying breathing gas to the goggles for venting thereof so as to prevent the entrance of smoke or disabling gases and to defog the lens.

Abstract: A breathing apparatus includes a regulator which delivers air to a user wearing a mask. The regulator is connected to the mask through an adaptor. The adaptor includes an exhalation valve which enables the user's breath to pass out of the adaptor to atmosphere. The regulator includes a sensing diaphragm that is movable responsive to pressure in the mask. A main valve delivers air to the mask responsive to opening of a pilot valve. The pilot valve includes a pilot opening. A lever moves in response to the sensing diaphragm to open the pilot opening which causes flow through the main valve. Air from the main valve is also delivered to a positive pressure chamber. Pressure in the positive pressure chamber moves a positive pressure diaphragm which causes a positive pressure spring to biasingly engage the sensing diaphragm. The biasing of the sensing diaphragm causes the regulator to maintain a positive pressure in the mask.

Abstract: A chemical oxygen or other gas generator which has a container composed of thermally-conductive and gas-impervious material which contains pyrotechnic material, the container being in heat transfer relation with a block of oxygen-producing material for transfer of heat from burning of the pyrotechnic material within the container directly to the block of oxygen-producing material for initiation of decomposition thereof. The container is sealingly attached to the casing so that all of the evolved gases from burning of the pyrotechnic material are segregated from the produced breathable oxygen. The evolved gases are vented from the oxygen generator so as to reduce the ignition chamber pressure and/or allow a greater amount of pyrotechnic material to be burned within the ignition chamber so that a sufficient amount of heat may be generated within the ignition chamber for application to the block of oxygen producing material for initiation of decomposition thereof.

Abstract: A pressure indicating device for self contained breathing apparatus includes a piston arrangement which is responsive to the relative pressures of the supply and the pressure at the outlet of the first stage regulator to assume several different positions in the containment housing. Piston position is recognized by electronic circuitry and an LED display is lighted accordingly to provide a series of unique signals to the user, of the remaining quantity of breathing fluid. In one embodiment of the invention, plural, graduated-size pistons provide a progressive indication of the air supply. In another embodiment, a single, stepped piston effects progressive electrical contact at various positions in the travel of the piston.

Abstract: A face mask for covering the nose and mouth of the wearer for supplying breathing gas thereto and a pair of strapless goggles which are easily and quickly donnable. The goggles are detachably attachable to the face mask by a tongue-and-groove connection wherein the tongue of the goggles is snapped into the face mask groove. Buttons are provided at the groove entrance for locking the tongue in the groove, the goggles being removable by depressing the buttons and sliding the tongue out over the depressed buttons. A face mask strap is coupled with hooks on the goggles frame for holding the goggles sealingly against the wearer's face. A vent is provided for supplying breathing gas to the goggles for venting thereof so as to prevent the entrance of smoke or disabling gases and to defog the lens.

Abstract: An apparatus designed for the testing of micro-machined torsional mirrors at the wafer level is described. A control station is coupled to an electro-optic assembly that has been designed for the purpose of testing mirrors. Three standard probes are coupled to the electro-optic probe assembly to provide electrical connections to a particular mirror of a wafer under test. Optical components are coupled to the electro-optic probe to deliver laser light to a deflectable plate portion of the mirror. Displacement of the reflected laser light spot is detected as the mirror plate is vectored and this displacement is compared to specifications such that the mirror under test can be either accepted or rejected.

Abstract: A facepiece insert and facepiece combination suitable for use as a respiratory mask. The respiratory mask may be combined with air purifying cartridges or breathable gas sources such as oxygen reservoirs. The insert is molded flat with living hinges, and the facepiece body is molded onto the insert in sealing engagement.