Abstract: A gas detecting and measuring device and method highly selective for the detection of certain gases is described. The gas detector is capable of detecting and measuring a gas which can be electrochemically oxidized or electrochemically reduced at a voltage of between about 0.6 and 1.5 volts relative to a standard hydrogen electrode. The gas detecting and measuring device and process are highly selective for the oxides of nitrogen (NO.sub.x) and chlorine. The gas detecting device utilizes a hydrated, solid polymer electrolyte ion transporting membrane in electrical contact with an improved catalytic graphite sensing electrode. For detecting an oxidizable gas such as nitric oxide (NO), an improved graphite anode in contact with the solid polymer electrolyte is used with a cathode and a reference electrode as an electrochemical cell, and for detecting a reducible gas such as chlorine (Cl.sub.2) or nitrogen dioxide (NO.sub.

Abstract: A mass rate of flow meter with a first magnet and sensing coil for detecting the passage of an unrestrained rotor past the sensing coil. The position of a restrained turbine reactor is sensed by locating an axially extending magnetic flux linkage near the periphery of the turbine with an extension that is disposed in an axially overlapping relationship with a magnet that extends from the periphery of the rotor. A flux collecting ring on the periphery of the turbine is coupled to the magnetic flux linkage to provide a low reluctance magnetic circuit that couples flux from the first magnet to the sensing coil.

Abstract: An improved cylindrical conduit for directing fluid flow to the swirl generator of an angular momentum type rate of flow meter commonly employed in measuring fuel flow rate in aircraft engines. The conduit includes a first set of longitudinally extending, resilient fingers and a second set of concentric sealing fingers that seal the resilient fingers in the first set. At low flow rates, the sealing fingers prevent leakage between the resilient fingers and the conduit directs substantially all fluid to the swirl generator.

Abstract: A unique, current conducting bipolar separator in a cell for electrolysis of chlorides makes multiple contact with the anodes and cathodes bonded to an ion transporting membrane in an electrolysis cell. Each side of the separator plate includes a plurality of electrode contacting, current conducting ribs or projections which also define a plurality of flow channels to allow fluid transport and good flow distribution. The projections or ribs on opposite sides of the separator plates are angularly disposed relative to each other so that the membrane is supported on one side by ribs of one separator and on the other side by the ribs from another separator which are angularly disposed to the first group. The intersection of the ribs on opposite sides of the membrane, thus, establishes a plurality of pressure areas or bearing surfaces which support the membrane without deforming it and without requiring very precise registration and alignment of the ribs.

Abstract: The disconnect arrangement for high speed aircraft generators includes disconnectable rigid, torque transmitting spring loaded curvic gears coupled between the driving and driven shafts. A plurality of flexibly supported sear members mounted on the driven shaft engage the movable member of the curvic gears. The sears have tapered faces which engage correspondingly tapered shoulders on the movable curvic gear member. The sears are latched to hold the curvic gear members in contact by the armature of an electromagnet. The armature normally rides over the top of the gears maintaining them in contact with the tapered shoulder of the curvic gear member. When the electromagnetic armature is actuated to disengage the driving and driven shafts, the armature moves axially. This removes the retaining force from the tapered sears, allowing them to flex outwardly.

Abstract: A compact electrochemical gas sensing cell is described for detecting gases such as carbon monoxide, NO.sub.2, alcohol vapors, etc. The cell is characterized by temperature stability during zero-air operation so that background current with no gas flow is eliminated or minimized. This cell utilizes a hydrated, solid polymer electrolyte having reference, sensing and counter electrodes mounted on the surface thereof with one side of the membrane being flooded with distilled water to provide self-humidification of the cell by water vapor transport across the membrane. A potentiostatic circuit is utilized to control the potential on the sensing circuit and also to maintain a fixed potential difference between the reference and the sensing electrodes. In addition, the chemical, electrochemical, and thermal characteristics of the sensing and reference electrodes are matched so that the sensor is highly temperature invariant during zero-air operation.

Abstract: An apparatus and method for reducing the overvoltage transients present on the alternating current power signals provided by the cycloconverters of a variable speed constant frequency (VSCF) system during the first several cycles of the alternating current after a load reduction or no-load condition occurs. An overvoltage transient reduction circuit is connected to each of the plurality of D.C. control signals provided by the phase voltage regulators to the waveform generator of a conventional VSCF system. The overvoltage transient circuit and method of the present invention senses the current amplitude level in each of the alternating current power signals in the VSCF system, and automatically reduces the voltage amplitude levels of the D.C. control signals provided by the phase voltage regulators to a preselected lower level within one-half cycle of the alternating current after a load reduction occurs. This reduction in the amplitude level of the D.C.

Abstract: A halogen, such as chlorine, is generated by electrolysis of an aqueous solution of an alkali metal halide such as sodium chloride, in a cell having anolyte and catholyte chambers separated by a solid polymer electrolyte in the form of a stable, selectively cation permeable, ion exchange membrane. One or more catalytic electrodes including at least one thermally stabilized, reduced oxide of a platinum group metal are bonded to the surface of the membrane. An aqueous brine solution is brought into contact with the anode and water or an aqueous NaOH solution is brought into contact with the cathode. The brine is electrolyzed to produce chlorine at the anode and hydrogen and caustic at the cathode. The cell membrane preferably has an anion rejecting cathode side barrier layer which rejects hyroxyl ions to block back migration of caustic to the anode thereby enhancing the cathode current efficiency of the cell and of the process.

Abstract: The invention describes a pressurized, three compartment membrane cell for the electrolyzing aqueous alkali metal halides at low cell voltages and with high cathodic current efficiencies. Unitary electrode-electrolyte structures, in the form electrochemically active electrodes physically bonded to ion transporting permselective membranes divide the cell into anode, cathode and buffer compartments. The buffer compartment feed is pressurized to maintain at a positive pressure differential with respect to the anode and cathode compartment feeds. The flexible unitary electrode-membrane electrolytes are forced outwardly against electronically conductive anode and cathode current collectors to provide uniform, constant and controllable contact between the bonded electrodes and thereby minimizing ohmic losses.

Abstract: An electrochemical cell such as a fuel cell comprising an ion exchange membrane electrolyte and catalytic electrodes bonded to the surface of the membrane is provided with a wet proofed carbon paper current collector at the oxidizing electrode. The use of a wet proofed carbon paper current collector allows axial current collection from the bonded electrodes thereby avoiding the need for conductive screens directly in the bonded electrodes. The wet proofed carbon paper by virtue of its hydrophobic character prevents flooding of the electrode by the cell product water.

Abstract: A bipolar current collector-separator for electrochemical cells consists of a molded aggregate of electro-conductive graphite and a thermoplastic fluoropolymer combined in a weight ratio of 2.5:1 to 16:1. The bulk resistivity of such a molded bipolar current collector-separator is less than 4.times.10.sup.-3 ohm inches (.OMEGA. in.). It has excellent corrosion resistance to a variety of feedstocks such as brine, aqueous HCl, etc. and to various electrolysis products such as caustic, chlorine, hydrogen, etc. In one alternative form the anodic side of a current collector-separator for a water electrolyzer is covered by a thin layer of a passivated metallic foil thus protecting the graphite current collector against attack by oxygen.

Abstract: The invention describes a self pressurized three compartment, membrane cell and a process for electrolyzing aqueous halide solutions at low cell voltages and high cathode current efficiencies. Electrochemically active electrodes are physically bonded to ion exchanging membranes which divide the cell into three compartments. The mass transport characteristics of the membranes are selected so that water brought into the center or buffer compartment along with the halide ions exceeds water transport out of the compartment. This results in good electrode to current collector contact as the membranes to which the electrochemically active electrodes are permanently bonded are forced against the current collectors.The instant invention relates to a process and apparatus for the electrolytic production of halogens and alkali metal hydroxides from aqueous alkali metal halide solutions.

Abstract: A unique, current conducting, separator element with controlled anolyte flow distribution is incorporated in an electrolysis cell having anode and cathode electrodes bonded to an ion transporting membrane. The current conducting-fluid distributing separator has a plurality of parallel conductive ribs which contact the anode electrode and also define a plurality of fluid distribution channels through which an anolyte such as water, is brought to the electrode and through which gaseous electrolysis products and the spent anolyte are removed from the anolyte chamber. A pressure dropping flow restrictor is provided in the channel inlets to prevent gases generated at the anode from flowing backward and blocking the anolyte distribution inlet manifold. The pressure dropping element can take the form of a restrictor to reduce the dimension of the channel. Alternatively the separator is molded so that the inlets of the channels have a reduced cross section.

Abstract: A halogen, such as chlorine, is generated in an electrolysis cell in which at least one of the cell electrodes is bonded to the surface of a solid but porous membrane which separates the cell into anode and cathode chambers. A pressurized aqueous metal halide such as brine is electrolyzed at the anode to produce chlorine. Brine anolyte and sodium ions are hydraulically transported across the porous membrane to produce caustic (NaOH) at the cathode. By bonding at least one gas permeable, porous electrode to the hydraulically permeable membrane, the cell voltage for electrolysis of brine is considerably lower than that required for asbestos diaphragm cells, while achieving high cathodic current efficiencies by minimizing back migration of caustic to the anode.

Abstract: A compact electrochemical gas sensing cell is described for detecting gases which are either immediately dangerous to health such as carbon monoxide, NO.sub.2, etc., or represent a social or public welfare risk. The latter area, for example, may require determining alcohol breath content of a driver of a motor vehicle. The cell uses a hydrated, solid polymer electrolyte which has sensing and reference electrodes positioned on one side of the solid polymer electrolyte membrane and a counter electrode positioned on the other side. One side of the hydrated SPE membrane is flooded with distilled water so that incoming gases are brought to essentially 100% relative humidity by rapid vapor phase water transport across the membrane, thereby eliminating the need for external humidification in the form of bubblers and the like. An ionically conductive hydrated SPE bridge is formed on one side of the membrane and is located spatially to provide a low resistance path between the reference and sensing electrodes.

Abstract: A flowmeter of the fluid oscillator type having a fluid jet which oscillates at a frequency indicative of flow rate. A linear flow rate vs. frequency output characteristic is obtained by use of a fluid accelerating means in the form of a two-dimensional sharp edge orifice. The orifice has an aspect ratio selected to give a constant coefficient of discharge throughout an extended flow range including laminar and turbulent flow conditions.

Abstract: The instant invention relates to a system for estimating aircraft angle of attack .alpha. and sideslip angle .beta. from measured quantities such as angular body rate and linear acceleration. The estimated angle of attack and sideslip signals are generated by means of a Kalman filter configuration which simulates a model of the aircraft angle of attack and sideslip angle dynamics, and may be used either in an aircraft flight control network or for display purposes.

Abstract: The invention relates to a flight control system for an aircraft which maintains reliable control of the angle of attack (.alpha.) in those regions where rate of change of the lift coefficient (C.sub.L) as a function of .alpha. goes to zero or becomes negative. This may cause a condition in which the feedback loop for the pitch moment generating control surface can inadvertently drive the aircraft into a stall or other unstable mode. Reliable control of angle of attack is achieved through a network which produces an estimated angle of attack signal (.alpha.) from the measured pitch rate of the aircraft, the lift acceleration error signal, a gravity control signal and sideslip and roll information. The estimated angle of attack signal is processed in a network which produces a pseudo coefficient of lift signal C.sub.L. The pseudo lift coefficient signal is processed to produce a pseudo lift (or normal) acceleration signal, A.sub.Z, which is supplied to the aircraft control loop.

Abstract: Signals from a source of flight path data, normally a memory device which stores forward-looking radar data, for example, are sampled in "reverse-time". That is, the data points along the flight path are taken in reverse order relative to the direction of flight. By simple circuits, the signals from the flight path data source are modified to conform with the basic criteria of the desired flight and with other desired parameters such as vertical acceleration and velocity limits so that a reverse-time flight simulation is made. The special "inside-out" form of indicia is a pair of bands which are fence-like in appearance and form the vertical sides of a tunnel-like outline, along the vertical center of which is the desired flight path. By generating these bands on a cathode ray oscilloscope with vertical displacements in accordance with the desired flight path and relative vertical widths in perspective with the range, the curved center line is easily followed.

Abstract: Method and sighting apparatus for aerial bombing from a curved approach path in a plane other than a vertical plane. Computer calculates and drives proper lead angle for sight which includes a reticle for target tracking with freedom to move in two dimensions. Computation, which is based on the relationship of lead angle and rate of turn of the aircraft in a curved flight path through the bomb release point, also considers airspeed, initial distance to target, bombing distance from target, aircraft mass, and can account for wind velocity, bomb characteristics and air density.