Abstract: A breathing gas supply system for an aircraft includes a plurality of oxygen concentrating apparatus, each of which in use, is operable to supply oxygen enriched gas to a breathing gas supply. Each oxygen concentrating apparatus includes at least two active molecular sieve beds which are operable so that while one sieve bed is adsorbing non-oxygen gas from a pressurized gas supply, the or another bed is being purged of non-oxygen gas by subjecting the bed to lower pressure. Each oxygen concentrating apparatus includes an oxygen enriched gas flow control device which permits the flow of oxygen enriched gas produced by the oxygen concentrating apparatus to the breathing gas supply and permits a restricted flow of oxygen enriched gas from the breathing gas supply to the oxygen concentrating apparatus. Oxygen enriched gas produced by the adsorbing sieve bed flows direct to the bed being purged.

Abstract: An electric motor assembly e.g. for an air cycle air conditioning apparatus comprises stator windings and a rotating member mounted for rotation about a motor axis and wherein, the stator windings comprise therethrough at least one axially extending passage, and there being means to connect the passage to a source of cooling gas, whereby as the cooling gas flows along the axially extending passage the motor assembly is cooled.

Abstract: An aircrew breathing regulator having facility for mixing ambient air with oxygen-enriched breathing gas in supplying breathing gas to an end user, includes a demand valve connected between an inlet for receiving oxygen-enriched breathing gas and an outlet for delivering breathing gas to the end user. Ambient air is entrained by flow of oxygen-enriched breathing gas through an injector nozzle to enter an ambient air inlet and mix with the oxygen-enriched breathing gas downstream of the demand valve. Pressure build-up downstream of the demand valve resulting from the flow restricting effect of the injector nozzle causes a pressure feedback onto a head of the valve tending to force it closed. This is overcome by nullifying the action on the demand valve of downstream pressure so that the valve is pressure balanced.

Abstract: A breathing demand regulator for use in aircrew life support apparatus has an aneroid capsule 56 coacting with a valve head 50 to restrict outflow from a breathing pressure control chamber 32. The aneroid capsule expands to move the valve head in the event of aircraft cabin altitude rising above a predetermined level due to loss of cabin pressure. An end face 53 of a valve stem 51 supporting the valve head senses inflation pressure of an aircrew G-suit by way of a passageway 59 for movement of the valve head in the presence of G-load. This arrangement provides for increased control pressure and, hence, increased breathing gas pressure in a regulator outlet 13, in meeting the higher of requirements for positive pressure breathing to protect an aircrew member exposed to both G-load and high aircraft ambient altitude (say above 12000 meters).

Abstract: A system and apparatus are disclosed for providing oxygen-rich gas for breathing by aircrew and passengers of commercial passenger aircraft. Oxygen-rich gas output by molecular sieve concentrator apparatus 11 is delivered by way of a compressor 17 and a priority valve 24 to a flight crew gas storage cylinder 22 and passenger gas storage cylinders 23. An electronic control unit (ECU) 38 controls cycling of the concentrator apparatus 11 in obtainment of gas enriched with oxygen to at least 90%. The ECU is connected for receiving signals from a monitor 35 which senses the content of oxygen in gas delivered by the concentrator apparatus. The ECU receives signals from pressure sensors 42 and 43 in the cylinders 22 and 23 to initiate start up of the system when the content of these cylinders is sensed to have fallen below a predetermined value. The ECU is connected to switch the priority valve for preferential charging of the crew cylinder when both sets of cylinders require charging.

Abstract: Aircraft aircrew life support apparatus has a G-protection garment inflation pressure control valve disposed in a common body with a breathing demand regulator. Inflation pressure output by the garment inflation pressure control valve is ducted within the body to be directly applied as an operating force to a valve controlling outflow from a breathing-pressure control chamber of the regulator whereby positive pressure breathing obtains in the presence of G-load. The garment inflation pressure control valve comprises a pressure balanced valve adapted to be displaced against the bias of a spring in an opening direction by a pneumatic actuator. The pneumatic actuator is controlled by signals from an accelerometer sensing G-load for inflation of the garment when the aircrew member is subject to high G-load (typically in excess of 2G) and by signals from a cabin pressure sensor for inflation of the garment if the aircrew member is exposed to high altitude (typically in excess of 12000 metres).

Abstract: A two stage fluid compressor is operated by a pneumatically operated relay valve controlled by a fluidic switching device in which switching pulses of pressurized control air are obtained automatically on movement of a compression piston in one of the compression stages.

Abstract: An aircraft on-board oxygen generation system having a controller 14 for cycling sieve beds of amolecular sieve-type gas separation system 10, provides product gas having a partial pressure of oxygen that more closely approaches the ideal value at any cabin altitude within the operating range of the aircraft. The controller stores a look-up table of desired product gas oxygen content at various altitude levels within the operating range and displays desired product gas oxygen content at altitudes sensed by an altitude sensor 17 for comparison with delivered product gas oxygen content sensed by oxygen content sensor 19. The controller provides for a range of selectable cycle time and adjusts the cycle time in the sense required to null the difference between displayed and sensed oxygen content of the product gas.

Abstract: An aircrew life support system has an on-board oxygen generating system (OBOGS) connected for delivering oxygen-enriched product gas to a breathing demand regulator and a plenum storage container. The concentration of oxygen in the product gas is sensed by a gas concentration sensor which supplies signals to an electronic control unit (ECU). The ECU outputs signals for switching a control valve which controls product gas to be delivered to the regulator from either the OBOGS or the storage container. The ECU also outputs signals to a charge valve which is opened to allow product gas from the OBOGS to charge the storage container when product gas enriched with oxygen above a predetermined concentration is being delivered by the OBOGS and there is excess capacity over the demand requirements at the regulator.

Abstract: Apparatus for generating oxygen enriched air from a flow of ram air supplied to a hydraulically driven air compressor 10 by way of an inlet 11. After pressure intensification the air is delivered to a gas concentrator unit 50 (shown in FIG. 2) through a supply line 90.Molecular sieve beds provided by the concentrator unit 50 are cycled through charge/adsorption and purge/desorbtion phases by pilot valves 65, 66, 67 operated by cams 30, 31, 32 respectively, mounted for rotation on a shaft 33 driven by the compressor through a reduction gear box 35. A flueric partial pressure sensor 80 senses the partial pressure of oxygen in the oxygen-enriched air delivered from the concentrator unit and, by way of low pressure transducers 81, 82, signals a flow control valve 86 to control flow of hydraulic fluid to an inlet 19 of the compressor 10.

Abstract: A molecular sieve bed container provides a plurality of molecular sieve bed chambers. The chambers are formed by tubular wall members concentrically located within a tubular outer housing and are closed at their ends by end closure members. One end closure member incorporates valves (not shown in FIG. 1) for controlling supply of charge gas to the sieve bed chambers and venting of purge gas from the sieve bed chambers. The other end closure member incorporates valves for controlling passage of product gas from the sieve bed chambers to an outlet (not shown) and portways for permitting some of the product gas to flow back through the sieve bed chambers as purge gas during a purge/vent phase.

Abstract: The concentration of a constituent gas in a product gas delivered by a molecular sieve type gas separation system 10 is controlled by a flueric partial pressure sensor 15 connected to a spill-valve 16 which is conduitly connected to a product gas delivery duct 13. The flueric partial pressure sensor 15 compares a reference bleed of supply gas with a sample bleed of product gas and outputs signals to control the spill-valve in spilling product gas from the delivery duct 13 so that the rate of flow of gas through adsorption beds 11 of the system 10 is controlled to provide product gas having a required concentration of the constituent gas.