Abstract: A method is described for using acoustic waves to hold an object in position against wandering in any direction, by the use of a single transducer. Formulas are provided for levitating an object along an axis of a rectangular or cylindrical chamber or the center of a spherical chamber. The formulas take into account the relative volume of the object to the chamber.

Abstract: A system which can be set up in emergencies to moor an offloading vessel and transfer oil between it and a seabed pipeline, as to remove oil from a grounded tanker or to deliver fuel to the shore under hostile or emergency conditions. The system includes a barge containing a fluid swivel as well as a mooring buoy and buoy-holding chain. The barge can be towed to a desired location and pipes and hoses connected to the fluid swivel, and the barge then can be sunk to the seabed. Upon sinking, the barge is already connected to the seabed pipeline and to hoses that extend from the barge to the sea surface to connect to an offloading vessel, as well as being connected through a chain to a buoy floating at the sea surface which has a hawser for mooring the vessel. A vessel can be utilized to tow out the seabed pipeline, to facilitate installation of the pipeline as to enable connection of the pipeline to the fluid swivel on the barge prior to sinking the barge.

Abstract: A method and apparatus for making decay time measurements of an optical cavity having at least two reflecting optical elements by directing a beam of light into the cavity, switching the beam of light off when the intensity in the cavity reaches a predetermined threshold level, monitoring the beam intensity decay of the optical cavity, and measuring the intensity decay time either with a storage oscilloscope or a digital counter.

Abstract: A polyphase SCR inverter (10) having N switching poles, each comprised of two SCR switches (1A, 1B; 2A, 2B . . . NA, NB) and two diodes (D1B; D1B; D2A, D2B . . . DNA, DNB) in series opposition with saturable reactors (L1A, L1B; L2A, L2B . . . LNA, LNB) connecting the junctions between the SCR switches and diodes to an output terminal (1, 2 . . . 3) is commutated with only one GTO thyristor (16) connected between the common negative terminal of a dc source and a tap of a series inductor (14) connected to the positive terminal of the dc source. A clamp winding (22) and diode (24) are provided, as is a snubber (18) which may have its capacitance (c) sized for maximum load current divided into a plurality of capacitors (C.sub.1, C.sub.2 . . . C.sub.N), each in series with an SCR switch S.sub.1, S.sub.2 . . . S.sub.N). The total capacitance may be selected by activating selected switches as a function of load current.

Abstract: An improved servo demodulator channel employing a transconductance balanced modulator as a polarity switch, an AGC amplifier and a signal separation circuit. A transconductance balanced modulator comprises two amplification transistors and four output transistors which together form two signal channels, each comprised of an amplification transistor connected in parallel to two output transistors. In a specific embodiment, the transistors are n-p-n transistors, the emitters of the two output transistors associated with a given channel being connected to the collector of the amplification transistor. The transconductance balanced modulator is configured so that the two amplification transistors are interconnected as a differential amplifier, and the base electrode of an output transistor in one signal channel is connected to the base electrode of an output transistor in the other signal channel, the base electrodes of the other two output transistors also being interconnected.

Abstract: A two-segment contact buried heterostructure (BH) laser is pumped by a current applied to its absorber contact from a source of high impedance on the order of 100K.OMEGA. or more. The parasitic resistance between the absorber contact and the gain contact is high on the order of 10K.OMEGA.. For a given absorber (bias) current the laser exhibits a relatively wide hysteresis on the order of 1 mA or more in the light vs. gain contact current. Such a laser is highly useful as a bistable optical element. The laser is also bistable with selected pump gain and absorber currents to exhibit a wide hysteresis of voltage across the absorber contact vs. relative amounts of light which is reflected back to the laser as feedback. The laser serve both as a light source and as a detector for reading out binary information stored as light reflective spots on a medium, e.g. a video disk.

Abstract: A portable analysis spectrometer (10) for field mineral identification is coupled to a microprocessor (11) and memory (12) through a bus (13) and A/D converter (14) to display (16) a spectrum of reflected radiation in a band selected by an adjustable band spectrometer (20) and filter (23). A detector array (21) provides output signals at spaced frequencies within the selected spectrometer band which are simultaneously converted to digital form for display. The spectrum displayed is compared with a collection of spectra for known minerals. That collection is stored in memory and selectively displayed with the measured spectrum, or stored in a separate portfolio. In either case, visual comparison is made. Alternatively, the microprocessor may use an algorithm to make the comparisons in search for the best match of the measured spectrum with one of the stored spectra to identify the mineral in the target area.

Abstract: A method is described for producing and projecting a theater quality entertainment motion picture, by photographing and then projecting the motion picture on a screen, which creates an unusually vivid impression of realism. The film frames have a resolution of over 40 line pairs per milimeter, and each frame has an area of at least 0.36 square inch, which creates more than 10 million pixels per frame on the film and on the screen. The illumination level on the screen is at least 15 foot lamberts. The film frames are photographed and projected at a predetermined constant rate of more than 50 frames per second, such as 60 fps. The high resolution and light level, combined with the unusually high frame rate, has been found to produce an unusually vivid impression of realism.

Abstract: A tuning arrangement (10) for a tunable laser comprises a single holographic grating (12) and two flat surface reflective mirrors (13 and 14). The beam (15) from the laser cavity is incident on the grating at a grazing angle for optimum beam expansion. The diffracted beam propogates from the grating to the first mirror (13), therefrom to the second mirror (14) and is reflected at the Littrow angle to the grating, whereat it is diffracted a second time and returned to the second mirror (14) for reflection to the first mirror (13). Therefrom it is reflected back to the grating. After undergoing a third diffraction it is directed back into the cavity for further amplification.

Abstract: A magnetic tape transport for recording digital data. The tape transport is selectively operable in either a parallel write mode for recording concurrently along multiple tracks in a standard format or a high density serial write mode for recording along one track at a time, the multiple tracks being recorded in sequence in a serpentine format. The transport uses standard multitrack read and write heads with each head having N transducers, where N is a positive integer greater than 1, supplemented by an additional multitrack read head or write head with N/2 transducers for N even or (N-1)/2 transducers for N odd, so that for either direction of tape movement, the tape will first pass a write head and then a read head. When moving in a first direction (forward) the tape will move past the write head and then past the first read head.

Abstract: A particle discharge mechanism is described for use on a centrifugal dewatering system, which is of relatively simple and rugged construction. The discharge mechanism includes a pair of concentric ring-like gates (50, 52 in FIG. 2) that can move across a particle discharge passageway (46) extending around a rotating vessel (14). The gates are operated in a sequence to first trap a mass of particles inside the radially outermost gate (52), to close an innermost gate (50) to isolate the trapped particles, and then to open the outermost gate (52) to release the trapped mass. In one procedure, the outermost gate is opened only slightly prior to complete particle release, to remove small amounts of remaining water in the mass of particles.

Abstract: An electronic relay circuit for replacement of an A-type relay in a step-by-step selector and connector of a telephone exchange system is implemented with a first operational amplifier (10) connected to the tip (T) and ring (R) conductors of a telephone line, and a second operational amplifier (24') with hysteresis for use as a comparator. A capacitor (C1) with a diode (D1) in parallel couples the input terminal of the comparator to a reference voltage from a voltage divider (R1, R2) in order that signal transitions from the input amplifier appear as common mode signals for a period determined by the RC time constant of a coupling resistor (R3) for ON-HOOK to OFF-HOOK transitions limited in amplitude by the parallel diode (D1) and the RC time constant of a resistor (R4) connected to a source of negative voltage for OFF-HOOK to ON-HOOK transitions limited in amplitude by a series diode (D2). A diode (D3) in series with the voltage divider introduces a compensating voltage drop for the diode (D2).

Abstract: A machinegun pistol is described, which can be reliably switched between semi and full automatic modes by an operator holding the gun in a natural two-hand grip. The gun includes a bolt (20, FIG. 1) and a firing pin device 22 that each slide longitudinally, a trigger assembly with a primary sear (28) that is depressed by the trigger for semiautomatic operation, and an auto control member (34) that can be depressed to switch to full automatic operation. When the control member is depressed, it connects a secondary sear (36) with the primary sear. The bolt carries a cam (40) that can depress the secondary sear (36) when the bolt moves forward, to thereby repeatedly depress the primary sear (28) when the two sears are connected during automatic operation. The control member (34) is operated by depressing it into the frame, to avoid errors in the heat of battle. The depressable control member (34, FIG.

Abstract: Halftone images are formed from dots selected from a dot character font memory storing information representing halftone dots of different sizes and shapes corresponding to different gray scale tone values or image densities. An original image is first scanned to sample its tone values at minute intervals exceeding the desired dot resolution of the reproduction. These sample values are digitized by an A/D converter which converts them to multibit binary numbers. Adjacent samples are compared to determine the average image density in a particular area, as well as the rapidity of rate of change of image density within that area. If the rate of change of image density in a given area is below a selected threshold value, the area is designated as low detail and the multibit binary number representing the result of the average density calculation over the area is used to select a dot character from the font memory for reproducing that area of the image.

Abstract: A label applying apparatus for use in an automatic labeling system for transferring labels sequentially supplied on an elongated carrier strip to articles conveyed therepast. The carrier strip is fed by a strip transport means past a separation station which separates the labels from the strip. The label applying means comprises a bellows and a control means for alternately pressurizing and evacuating the bellows to respectively extend and contract it. The bellows is mounted for movement from a first location to a second location in synchronism with the carrier strip. When contracted, the bellows engages a label at said first location up-path from the separation station and holds it by vacuum as it moves through the separation station toward said second location. The bellows is then extended at said second location beyond the separation station to thrust the label against an article conveyed therepast.

Abstract: An ice lubrication system for easing the passage of a ship through ice laden waters. A pressurized flow of water passes through a nozzle into the inlet of a mixing chamber comprising a venturi where gas from a gas manifold is mixed with the water. The effect of the venturi is to first cause the gas to mix into the water flow and, after passage of the flow through the venturi, to cause the gas to emerge from the water. A frothy combination of gas bubbles and water is thus created which is discharged through openings in the ship's hull below the waterline. Once discharged, the gas and water combination rises up the side of the hull to provide separation and lubrication between the hull and floating ice.

Abstract: A positive feed drill having a spindle drive gear train and a spindle feed gear train, coupled to the drive gear train by side teeth on respective drive and feed coupling gears mounted on a common shaft, is provided with a spring between the feed coupling gear and a housing to bias the feed coupling gear against the drive coupling gear to feed the spindle forward as it drills. A positive stop prevents the spindle from feeding beyond a predetermined point, thus causing the feed coupling gear to be driven by the spindle. A slope on the faces of the side teeth engaging the drive and coupling gears in order to allow the feed coupling gear to ratchet over the drive coupling gear when the spindle feed reaches the positive stop.

Abstract: The microscopic pores, cavities and crevices of the strings and the interstices of a wound string are filled with dry lubricant particles using a moisture displacing agent and rust inhibitor as a carrier for the dry lubricant. This provides lubrication and inhibits corrosion, thus shortening initial break in periods and extending string life.

Abstract: A relatively simple and compact apparatus is described for producing and/or monitoring a plurality of reference pressures wherein all the pressures must be precise and, especially, precisely related to each other. The apparatus includes a plurality of manometers, each including a reservoir and an elongated vertical tube connected together at their lower ends and partially filled with a manometer liquid such as mercury. As an example, a first (lower) reference pressure such as 150 torr (150 mm Hg) is connected to the reservoir of a first manometer while a second reference pressure such as 300 torr is connected to the reservoir of a second manometer of the same construction. The liquid in the vertical tubes will be at the same level only when the second reference pressure is precisely twice as great as the first.