Abstract: Apparatus for determining whether an intermediate terrain feature blocks the line of sight between a pair of spaced terrain points, comprising a linearly extending base, at least three spaced posts extending perpendicularly to the base and having cursors on them, the distances between the posts being selectively adjustable. In one embodiment, the base is of three telescopic sections, with a post mounted on each of the sections. In another embodiment, the base is fixed and has three sliders, on each of which a post is mounted. The posts are pivotally mounted on the base, so as to be stored substantially parallel to the base.

Abstract: A free field stress gauge capable of dynamic and static response in the kbar (nominally 15,000 p.s.i.) range is disclosed. A first embodiment of the stress gauge of this invention comprises two circular plates, one of which is concentrically grooved. The other plate of the two circular plates serves as a cover plate. Strain gauge sensors are mounted on the inner ring or tube of the concentrically grooved plate. These sensors measure strains of the inner ring or tube induced by and proportional to stresses applied to the flat faces of the gauge. The second embodiment which operates in the same manner as the first embodiment is a solid column type of stress gauge.

Abstract: There is provided a method and apparatus for treating sewage, by first comminuting raw sewage in a comminuting compartment to provide a slurry and then digesting the raw, comminuted sewage by oxygen-dependent bacteria in a roofed compartment. Oxygen is supplied by electrolysis of the water in the sewage, utilizing spaced anode and cathode. The anode is located in the roofed digestion compartment, and the oxygen generated at the anode is used by the bacteria; the cathode is located in a chimney which extends through the roof or top of the plant, to atmosphere, and the hydrogen generated at the cathode is discharged to atmosphere through this chimney. A stirrer is provided in the digestion compartment to stir trapped oxygen back into the mass of sludge. A trapping or sedimentation compartment is provided after the digestion compartment, for settling out indigestible solids, and drawing off the remaining liquid.

Abstract: The instant Brinell sandwich transducer has a layer of small hardened steel alls between two layers of softer materials. The balls may be closely packed or separated into a less dense array by a spacer. Indentations in the softer materials indicate the maximum compressive forces that have been applied to the balls. The diameters of identations in a sampling pattern are measured by a microscope since such diameters indicate the magnitude of the forces which have been registered by the transducer. Good resolution over a range of more than a factor of 100 has been obtained. With pulses ranging from static to approximately half-sines with rise times of 0.1 millisecond and a fall time of 0.1 millisecond, rate effects have been insignificant. That is, the indicated gauge pressure is not sensitive to the rate at which the pressure is applied for a broad range of pulse rise times and durations. Also, these gauges incorporate high axial stiffness and flat geometry.

Abstract: A method and apparatus for detecting flaws in conduits or the like which prises positioning an annular array of Hall-effect devices transversely around the conduit, applying an electric current to the conduit to flow longitudinally therethrough so as to create a magnetic field around the conduit, sequentially scanning the Hall-effect devices to produce a series of output signals corresponding to the portions of the magnetic field sensed respectively by them, and comparing the output signals for nonuniformities among them, the nonuniformities being indicative of the existence and location of flaws.

Abstract: A navigational system for automatically positioning a platform relative to the earth's geopotential surface. A system is provided which includes an accurate self-contained attitude reference to the true vertical. The system includes an inertial platform which is rotatable relative to a level platform, each of the platforms being connected to a two axis gimbal. One of the platforms is also connected to a three axis gimbal which may be connected to the vehicle which it is desired to stabilize. Means are provided for sensing rotation of one platform relative to the other. An inertial platform position control computer is provided for generating first corrected signals to the three axis gimbal for automatically referencing the inertial platform to a datum reference spheroid. Additional computer means are provided for generating second corrected signals to the two axis gimbal to align the level platform with the true vertical to the geopotential surface of the earth.

Abstract: A hand tool particularly adapted for the rapid and efficient assembly of ge numbers of annular devices such as solder washers onto a plurality of uniformally spaced pins. The invention allows for the vertical stacking of one or more washers onto each pin, without the need for the tedious handling of each washer individually. The working structure is housed in a closable case to allow for operation by hand in a shaking motion without spilling the washers.

Abstract: A transportable bridge is provided which may be erected across a wide, e.g. 150 foot, depression, and with access to only one bank of the depression. The bridge comprises a pair of abutments and a plurality of deck units. The abutments are laterally extensible, and erectible, from a collapsed state; they each comprise a base, a pair of backstays pivoted to one end of the base, and a pair of beam columns pivoted to the other end of the base, the backstays and beam columns being at small, acute angles to the plane of the base in the collapsed position, and being erected to form a triangle in the use position. Connecting means at the free ends of the backstays and beam columns are automatically engaged upon erection. A pair of reaction beams each has one end pivoted to a beam column, intermediate its ends, and extends over the base and past the one end of the base: anchoring means anchor the reaction beams to the ground.

Abstract: A method is disclosed for optimizing the bandwidth of a radio receiver cale of receiving widely varying input data rates. The method may be utilized with known superheterodyne receivers having certain modifications to allow for the ability to vary the intermediate frequency and the center frequency of the associated bandpass filters over a continuous range of values. The method includes the steps of determining the optimum intermediate frequency bandwidth for a given input data rate, adjusting a tunable bandwidth filter to a center frequency which is a predetermined multiple of the desired intermediate frequency bandwidth, and producing an intermediate frequency equal to the tuned frequency of the filter.

Abstract: A map is segmented into columns and rows, and pairs of segments are lamind back to back in a particular manner: the segments of each column serially, and the columns serially. A marginal flap is provided at the top of each segment, wider than the segment and with a slot in it as well as the segment. A ring passes through the slots to hold the segments together, and to permit the viewing of two segments which are adjacent in the map.

Abstract: In this pioneering invention, electrical energy in alternating or direct current form at any selected power, voltage, current, or frequency, within wide limits, is converted and controlled to other forms of electrical energy at uniformly and continuously controlled output waveform and voltage or current by means of progressive variation of magnetic flux in associated magnetic paths. For electrical energy regeneration, this invention relies on electromagnetic induction in windings surrounding variable permeance magnetic paths of ferrimagnetic or ferromagnetic materials. The controlling means rely upon progressive saturation and/or domain rotation for selected portions of the magnetic paths to yield a uniformly controllable permeance within the magnetic paths. Feedback techniques are used to stabilize the output and provide the means for external control of power output in combination with a reference source.

Abstract: A process is described for extracting the most-likely estimate of pitch f a digitized speech signal. For each segment of speech analyzed, a measure of merit is constructed for each of several possible preselected pitch periods. These measures are periodically combined with previous measures of merit to determine a one most-likely choice of pitch period for a previous segment of speech.

Abstract: An automatic sequencing circuit is disclosed which recognizes a particular coded input signal, initiates a process or data operation, and provides a coded output indicative of the operation performed. The circuit is particularly suited to hardware implementation of the control graph of a directed-graph design for any equipment using digital logic circuits.

Abstract: A rate multiplier with which a given input binary pulse train generates an utput pulse train having a rate which is defined by the expressionR.sub.o = (R.sub.in .sup.. x )/(2.sup.. n)where R.sub.o is the output pulse rate, R.sub.in is the input pulse rate, n is the number of stages in a Johnson counter and x is any integer from 0 to 2n-1. The rate multiplier may be built in any of the common solid state technologies and, for any given technology, will operate reliably at a substantially faster rate than is usually possible. A plurality of rate multipliers may be cascaded to provide further control of the output pulse rate. Because of the cascading technique disclosed, only the first rate multiplier need be operable at the maximum required clock rate, with each succeeding cascaded rate multiplier being required to operate at a rate which is only 1/(2 .sup.. n) as fast as the previous rate multiplier.

Abstract: An apparatus for automatically maintaining constant the transmission time lay between a transmitter and receiver, given variations due to transmission path length or clock drift. A received signal is shifted a predetermined number of stages into a shift register before synchronization, and thereafter stages are added or subtracted as needed to maintain synchronization despite changes in transmission time delay.

Abstract: A pulse amplitude modulator which has particular utility in analog-to-digl and digital-to-analog converters of the continuous variable slope delta (CVSD) modulation type. A CVSD analog-to-digital modulator first compares an incoming analog signal with a synthesized signal. The error signal is periodically sampled, with the output of the sampler being a clocked binary signal having the same polarity as the error signal. This binary signal, which is the output signal for the CVSD modulator, is simultaneously tested for patterns of similar bits and utilized to correct the amplitude of the synthesized signal in the pulse amplitude modulator. The pulse amplitude modulator utilizes C-MOS transmission gates and filter circuitry to synthesize a digital signal which, when integrated, approximates the analog input signal.

Abstract: A field emission tip on which a metal adsorbate has been selectively deposited, and a method by which it may be manufactured. In a vacuum, a clean field emission tip is subjected to heating pulses in the presence of an electrostatic field to create thermal field buildup of a selected plane. Emission patterns from the selected plane are observed, and the process of heating the tip within the electrostatic field is repeated until emission is observed from the desired plane. The adsorbate is then evaporated onto the tip. The tip constructed by this process is selectively faceted, with the emitting planar surface having a reduced work function and the non-emitting planar surfaces having an increased work function. A metal adsorbate deposited on the tip so prepared results in a field emitter tip having substantially improved emission characteristics.

Abstract: A pitch analyzer is described which extracts, on a real-time or pipeline is, the pitch information from a speech signal. The analyzer converts the speech signal to a digital signal, shifts it into a delay line tapped at logarithmic intervals and constructs a measure of merit for each of many possible pitch periods. These measures are periodically transferred to a processor which combines them in a prescribed manner with previous information to select the one most-likely current value of pitch. Provision is also made, when the application warrants it, to select the best pitch value, with a delay of several frames, based on current information.