Abstract: A four stroke cycle internal combustion engine is presented having a sustained power stroke which results from a delayed mixing of a stratified charge. Use of delayed mixing of an overall stoichiometric air-fuel mixture results in formation of a low amount of the oxides of nitrogen. Delayed mixing of the stratified charge is achieved by placement of at least one Helmholtz resonator cavity in the head or closed end of each combustion chamber. The Helmholtz resonator cavity communicates with the top end of the main combustion chamber via a narrow slot. On the intake stroke of each engine cylinder, the main chamber is filled with a slightly fuel rich gaseous charge while the companion Helmholtz resonator cavity is filled with air. During the compression stroke some of the rich air-fuel mixture is forced into the resonator cavity via the communicating slot. At or near TDC, the air-fuel mixture in the main chamber is ignited.

Abstract: This invention relates to apparatus which provides a positive flow of ambient air through the temperature sensor of the fuel control equipment used with a turbofan engine. The temperature sensing element of the fuel control unit is bathed in a continuously fresh sample of ambient air drawn in from the engine inlet by an air-jet pump that is powered by pressurized air bled-off from the bypass fan duct.

Abstract: A sheet gift wrap package is comprised of two identical nests of folds positioned in a transparent plastic bag in back-to-back relationship. Each fold is comprised of at least two sheets of decorative gift wrap, the sheets being arranged in each fold so that a portion of each sheet is visible in the nests.

Abstract: A torque correlation ring is disclosed which forms a part of a test stand useful in measuring performance of aircraft turboshaft engines. The torque ring assembly comprises two annular rings separated from each other by four short equally spaced beams. One of the annular rings is fixedly attached to the frame of the test stand. The engine casing is attached to the second ring. Attachment is such that the engine is axially suspended within the annular rings with the propeller shaft on one side and the turbine exhaust on the other. Torque reaction forces on the engine casing stemming from supplying power to a propeller will be passed from the second annular ring to the frame mounted, first annular ring via the four beams. The magnitude of this torque is measured by means of strain gages mounted on each of the four beams. The electrically combined signal from the strain gages represent an accurate measurement of the torque forces being supplied to the propeller by the engine under test.

Abstract: A binary capacitor consists of a piston having a metallized band on its periphery. The piston is movable between first and second positions within a cylinder which carries two spaced metallized bands. One of the positions of the piston defines a position of maximum capacitance, i.e. where the band on the piston overlaps both of the cylinder bands. The second position of the piston defines a position of minimum capacitance; i.e. where the piston band clears at least one of the cylinder bands. The piston is latched in its stable minimum and maximum states by fixed permanent magnets located at the ends of the piston in combination with soft iron slugs at the ends of the cylinder. The piston is moved by appropriately energizing electromagnetic coils wound over the soft iron slugs on the cylinder.

Abstract: A four stroke cycle internal combustion engine is presented having a sustained power stroke which results from a delayed mixing of a stratified charge. Use of delayed mixing of an overall stoichiometric air-fuel mixture results in formation of a low amount of the oxides of nitrogen. Delayed mixing of the stratified charge is achieved by placement of a Helmholtz resonator cavity in the head or closed end of each combustion chamber. The Helmholtz resonator cavity communicates with the main combustion chamber via a narrow slot made around the periphery of the top end of the chamber. On the intake stroke of each engine cylinder, the main chamber is filled with a slightly fuel rich gaseous charge while the companion Helmholtz resonator cavity is filled with air. During the compression stroke some of the rich air-fuel mixture is forced into the resonator cavity via the communicating slot. At or near TDC, the air-fuel mixture in the main chamber is ignited.

Abstract: A flow stabilizer is presented which equalizes the flow of fluid through the passageways of the channel diffuser used with a centrifugal type rotary compressor. Slots are formed in the sidewalls of the flow separating vanes in the diffuser. The slots open into cavities within the vanes. The multiplicity of cavities communicate by means of openings through the diffuser wall into a common closed manifold. The fluid interconnection between the multiplicity of passageways in the diffuser and the encircling common manifold increases the operating range of the compressor since pressure surges in one or more passageways are quickly equalized.

Abstract: This invention relates to apparatus which harmlessly purges all fluids which leak from the fittings of a turbofan aircraft engine. Purging is achieved by passing a low speed flow of ventilating air along the exterior walls of the engine combustor section. This is accomplished by enshrouding the engine core with a cylindrical cowl. A space between the cowl and the engine combustor makes an annular shaped cavity. Ports in the cowl allow air to be brought into the cavity from the bypass ducting of the engine. The rapidly moving volume of air thus brought in vaporizes any fuel which leaks into the cavity. The vaporized air/fuel mixture is then exhausted into the hot gas plume emitted from the rear of the core engine.

Abstract: This invention concerns a programmable counter which can be preset to provide an output indication one pulse after the count of the incoming signal pulse train has reached the integer M, where M equals any binary real number over the range (0, 1, 2, 4, 8, 16, . . ., 32,768). The programmable counter can be preset to any one of the binary numbers using a 4 digit word.

Abstract: An electric discharge gas laser has a turbulence generator inserted in the flow path of the gas upstream of the optical cavity. The turbulence generator is illustrated as a screen. The turbulence is also disclosed as resulting from a vortex-causing blade inserted in the gas conduit. The turbulence resulting in the gas flow provides energy and specie diffusion to the outer walls at a rate relatively faster than laminar (molecular) diffusion, thereby permitting stable operations of the diffuse electric discharge at relatively higher powers.

Abstract: A low pollution combustor is shown for controlling gas turbine pollutant emission, especially NO.sub.x. Fuel is injected and mixed with air upstream of the combustion zone. An axially movable baffle controls the air flow so that the fuel-air ratio is precisely controlled passing into the primary combustion zone. A baffle recirculation zone prevents overheating of the walls. Dilution air is provided downstream of the primary zone for temperature dilution of the gases and to inhibit further formation of nitrogen oxides.

Abstract: A relay multiplexer for low level analog signals is disclosed. To provide a low cost system, inexpensive reed type relays are used. Such relays provide a high capacitive coupling from the relay contacts to the relay coil and thereby degrade the AC common mode rejection of the multiplexer. Common mode rejection is enhanced in accordance with the disclosure by (1) using an optical coupling to the relay switch and (2) slaving a floating relay power supply to the guard potential of the selected channel.

Abstract: A dual cycle turbine system is presented which includes a combination of two engines with different cycle pressure ratios. The two engines are cross connected by a common regenerator that enables low specific fuel consumption under partial load conditions.

Abstract: Apparatus is disclosed which provides an improved means of measuring the operating characteristics of a multiplicity of thermocouple reference junctions. The apparatus allows accurate sensing of temperature through use of both a measurement and reference junction thermocouple arrangement. The reference junction thermocouples are collectively encased and surrounded by an insulating medium which on one side abuts a metal plate serving as a heat sink of appreciable mass. The operating temperature of the heat sink is then monitored by a temperature sensitive resistor. Voltage drop across the resistor is convertible into a measure of system calibration.

Abstract: The time-to-go of the fuze of an artillery shell is digitally set after the round has been fired but before it leaves the muzzle of the gun. The communications link for setting the fuze includes a transmitting coil mounted on the gun muzzle and a receiving coil mounted on each shell round. The transmitting coil is energized with a plurality of signals on discrete frequencies. The output from the receiving coil is detected to derive one binary digit representing each discrete frequency. All the binary digits, "0" or "1", are simultaneously set into a binary counter in the fuze, so that the binary number represents the time-to-go.

Abstract: An apparatus for and method of suppressing infrared radiation emitted from hot metal parts at the aft end of a gas turbine engine and from the exhaust gas plume thereof during engine operation is provided and comprises a multiple purpose ejector vane assembly operatively attached to the engine for introducing cooling ambient air into the hot engine exhaust gases and hiding the hot metal parts and means attaching the vane assembly to the engine with the vane assembly comprising a duct structure for receiving and confining the engine exhaust gases and a plurality of radial ejector vanes supported by the duct structure for introducing cooling ambient air into hot engine exhaust gases during engine operation by ejector action while simultaneously imparting a spiral swirl to both the cooling ambient air and the exhaust gases with the swirl promoting mixing of ambient air within the duct structure and causing additional entrainment of ambient air downstream of the duct structure.

Abstract: The torque transmitted through a pair of helical gears mounted on a lay shaft imposes an axial force on the lay shaft which is reflected into fluid pressure to indicate the magnitude of the torque. By journaling the lay shaft within sleeves which are also the inner races of a pair of roller bearings its axial movements are sensitively transmitted to a nonrotating piston rod mounted in ball bearings within the bore of the lay shaft. The piston is displaceable into a cylinder supplied with pressurized lubricating fluid through a valve responsive to the axial displacenent of the piston. The fluid pressure in the cylinder balances the axial force transmitted to the piston and is proportional to the transmitted torque.

Abstract: An analyzer adapted to be mounted in a operable aircraft and including an oscilloscopic display of the detonation characteristics of each cylinder of an internal combustion engine. The signal input to the oscilloscope is derived from vibration sensors attached to the engine spark plugs. The synchronizing signal input to the oscilloscope is derived from pulses generated at the primary circuit of the engine magneto. Solid state electronic circuits are used throughout and switching provides the capability to separately study the characteristics of each cylinder.

Abstract: Disclosed is a crop harvesting machine for collecting stalk crops having seed pods near ground level. The harvester includes a horizontally disposed reel structure. As the reel rotates, bat-assemblies thereon successively urge the stalks of the crop against a cutter bar which severs them close to the ground. The cutter bar and its associated sickle drive assembly accommodate the irregular variations in ground contour, by reason of the interposition of leaf springs between the cutter bar assembly and the cutter carrying platform. When not required the flexible cutter bar feature can be disabled. Sensing fingers mounted on the underside of the machine relay information to an automatic elevational control unit assuring that the cutter carrying platform closely follows the contour of the ground.

Abstract: A carbon ring seal for a shaft rotating at high speed is capable of preventing high temperature, high pressure gas from entering the oil system. The carbon seal is constructed so that at ambient temperature it works as a controlled gap seal, but when the seal runner reaches its full thermal growth the seal then functions as a positive contact seal. The carbon seal ring is not pinned against rotation, but rotation is limited by means of an integral drag pad. The seal housing is provided with a plurality of calibrated holes for predetermined internal pressurization and cooling.