Abstract: A ground fault detection and shutoff system for underwater power transmisn provides protection to divers from swimming into electric fields. This system uses DC power to monitor the true resistance of the load system rather than the AC power to the load. The system comprises DC power supply, ground fault monitor, circuit breaker and isolation transformer which monitors the system's DC resistance to ground and shuts off the power system if the resistance falls below a preset value.

Abstract: An apparatus is disclosed for re-claiming used or damaged tube turns and rendering them equivalent to new tube turns with correctly oriented openings. A salvaged tube turn is temporarily fixed to a platform in a position such that the longitudinal axis of one of tube turn ends is approximately perpendicular to the plane of an adjacent circular track. The platform is moved so that the opening of the tube turn end is near the circular track. The circular track is then accurately centered with respect to the opening by use of a spider or the like which is temporarily fixed to the center of the track. Either the spider (and track) or the tube turn is moved so that the spider engages the interior of the opening.

Abstract: Known electronic countermeasures systems have difficulty handling some modern radar signals, for example frequency agile, frequency sliding or frequency coded signals. The invention disclosed overcomes the problems of the prior art by using an analog frequency dividing system to virtually instantaneously down-convert received signals in octave steps and in octave stages into the frequency regimes associated with the operation of processing devices, such as analog to digital converters, digital logic devices, surface acoustic wave devices, and charge coupled devices. Those processed signals which are selected for retransmission, perhaps in a modified form, are then up-converted into the region of the received signal by the appropriate number of stages of frequency multipliers.

Abstract: An apparatus is disclosed for re-claiming used or damaged tube turns and rendering them equivalent to new tube turns with correctly oriented openings. A salvaged tube turn is temporarily fixed to a platform in a position such that the longitudinal axis of one of tube turn ends is approximately perpendicular to the plane of an adjacent circular track. The platform is moved so that the opening of the tube turn end is near the circular track. The circular track is then accurately centered with respect to the opening by use of a spider or the like which is temporarily fixed to the center of the track. Either the spider (and track) or the tube turn is moved so that the spider engages the interior of the opening.

Abstract: Electron-beam stage X-Y positioning instrumentation is provided. The electron-beam stage has a number of metal blocks affixed to its bottom. Fixed orthogonal noncontact gage heads are used to sense the distance of the heads from the parallel faces of a proximate metal block. The position of the metal block vis-a-vis the position of the fixed referenced gage heads yields the X-Y coordinates of the stage. The stage is first coarsely positioned adjacent a preselected block.Thereafter the exact position of the stage is computed from the distances sensed by the gage heads. The electron beam electronics are automatically adjusted to the actual position of the stage thereby eliminating the relatively slow, fine positioning of the stage.

Abstract: TiB.sub.2 -carbon composites are produced by mixing the raw materials comprised of carbon, TiB.sub.2, pitch, and other reactants, forming a shaped article, processing in a nitrogen atmosphere up to 2100.degree. C., and in a noble gas above 2100.degree. C.

Abstract: A cathode component for a Hall aluminum cell is economically produced from a mixture of a carbon source, preferably calcined petroleum coke, and optionally calcined acicular needle petroleum coke, calcined anthracite coal; a binder such as pitch including the various petroleum and coal tar pitches; titanium dioxide, TiO.sub.2 ; and boric acid, B.sub.2 O.sub.3 or boron carbide, B.sub.4 C; forming said mixture into shapes and heating to a TiB.sub.2 -forming temperature.

Abstract: This invention relates to a system for storing a pulse modulated radio frequency signal and for accessing and reconstructing the stored signal repetitively whereby it can be retransmitted as desired, either at the same frequency or at a shifted or shifting frequency. An input delay line is sampled at a plurality of locations and the signal samples are stored by a plurality of capacitors. The capacitors are accessed at will and the stored samples are applied to locations on an output delay line similar to the input delay line, where the input signal is reconstructed.

Abstract: 1,3-alkylene-diazetidinediones-2,4, wherein alkylene contains at least 8 carbon atoms, are described. These compounds, which can be regarded as intramolecular dimers of alkylene diisocyanates, give rise to the latter on heating. Accordingly, these compounds are useful in a variety of situations in which it is desirable to have a compound which is stable on storage in admixture with other compounds such as polyols, polyamines and the like (which latter would react with a compound containing free isocyanate groups) but which can, at any desired moment, be converted by heating to the free diisocyanate. The latter then reacts with the other component(s) of the mixture to form a polymer.The above compounds are derived by cyclization of the appropriate cyclic allophanoyl halide.

Abstract: Disclosed is a microwave frequency generator for producing a microwave signal with high frequency accuracy, high spectral purity, low noise and high frequency stability. It is known to phase lock the fundamental microwave oscillator to a highly stable crystal oscillator at lower frequency and convert to a higher output frequency with a multiplier or harmonic generator but fm noise is also multiplied. The present invention avoids this problem by using MESFET frequency dividers to phase lock a microwave oscillator to a stable reference oscillator without the need for frequency multipliers. The MESFET frequency divider provides signal gain instead of loss during operation.

Abstract: Chloro-hydrocarbons are used as pitch binder modifiers to improve the strength, density and electrical properties of carbon and graphite articles produced from carbonaceous particles, binders, and additives, and are particularly useful in manufacture of electrodes used in ultra high powered electric arc steel furnaces.

Abstract: In an underwater-mateable connector system of the vented pin-and-socket t, the socket electrical contact system is composed of a contact ring cooperating with a contact band, the contact band being integrally provided with a multiplicity of resiliently deformable louvers. The pin electrical contact is composed of a rigid conductor disposed intermediate electrically insulating material and is arranged to provide electrical contact with the deformable louvers of the contact band. Electrically insulating interference seals are formed on either side of the contact area when mated due to differential diameters between the pin and socket. The preferred embodiment utilizes a Multilam.RTM. band (U.S. Pat. No. 3,453,587) as the contact band.

Abstract: It is known to generate mircowave frequencies by locking the fundamental output frequency of a microwave oscillator to a multiple or sub-multiple of the output frequency of a highly stable crystal oscillator operating at a lower frequency than the microwave oscillator. Phase-locked loops are used together with frequency multipliers or dividers. One problem is that the frequency lock range decreases as successively higher and weaker harmonics are used for locking. This limits the practical harmonic locking range to multiples of approximately less than ten. The present invention eliminates this problem and allows microwave signals which have a frequency greater than 10 times the reference frequency to be phase locked without an impractical reduction of the capture range. As well, in conventional phase locked loop systems which use multipliers, fm modulation which is intentionally injected must have a modulation index less than 1.0.

Abstract: The use of polyisocyanates as binders in the preparation of particle boards is subject to the drawback that the boards exhibit a tendency to adhere to the face of the platens used in their formation. This problem is minimized by utilizing, in association with the polyisocyanate to be used as binder, minor amounts of one or more phosphates or thiophosphates of the formula: ##STR1## where R=alkyl (C.sub.3 and higher), alkenyl (C.sub.3 and higher), aryl, alkyl-substituted aryl, ##STR2## (where R.sub.2 is alkyl, aryl, or alkyl-substituted aryl, A and B are H, methyl, chloromethyl, 2,2,2-trichloromethyl, m=1-25) and lower-alkyl substituted by from 1 to 2 acyloxy groups where acyl is the residue of an aliphatic carboxylic acid having at least 2 carbon atoms; R.sub.1 is Cl, Br, lower-alkoxy, lower-alkylmercapto, arylamino, mono(lower-alkyl)amino, di(lower-alkyl)amino, hydroxy(lower-alkylene)oxy, aryloxy, hydrocarbylureido, and an enol residue; X=O or S and n=1 or 2.

Abstract: A discriminator circuit having utility in proximity fuze firing circuits is apable of distinguishing between spurious and proper signals on the basis of both amplitude and rate of amplitude rise. A firing switch, operated by a slow-charging trigger circuit, and a lock out switch, operated by a fast-charging trigger circuit, are both triggered by the same signal. If the rate of input signal envelope rise is faster than that for a proper firing signal, the lock out switch fires and inhibits triggering of the firing switch. The trigger circuits are biased to permit the firing switch to be triggered before the lock out switch when the input signal rate of rise is slow enough to be followed by the slow-charging trigger circuit. For signal rates of rise which are slower than that associated with a proper signal, a capacitor in the slow-charging trigger circuit becomes charged to block triggering of the firing switch.

Abstract: Novel bis cyclic ureas are disclosed having the formula ##STR1## wherein C.sub.n H.sub.a n represents alkylene from 4 to 12 inclusive and provided there are at least 4 carbon atoms in succession in the chain and R is the residue obtained by the removal of both halogen atoms from a diacid halide.The bis cyclic ureas are easily converted to a novel class of aliphatic diisocyanates simply by heating. Alternatively, they are blended with polymeric polyols to form one-component storage stable compositions which are thermally converted to polyurethane resins without any significant volatile or side product formation.

Abstract: An improved blade retainer for locking radially projecting blades on a rotor includes an elastic spacer sized to be inserted into a radial space between the blade tang and the bottom of the rotor slot in a generally undeformed state without deformation of the tang or slot. The spacer is provided with a first arcuate surface which abuts the tang and a second arcuate surface which, in one embodiment, abuts the bottom of the rotor slot when the spacer is deformed, thereby exerting an outwardly directed load on the tang. The spacer is fixed against axial movement relative to the blades by means of a forward end lug which is in confronting and overlapping relationship with an end face on the blade tang when the spacer is deformed. Blocker means are insertable between the spacer and the bottom of the slot to retain the spacer in a deformed state and thereby bias the blade radially outwardly.

Abstract: It is known to measure the frequency of microwave signals by heterodyne conversion or by transfer oscillator techniques. Heterodyne conversion frequency counters are limited in their ability to measure the frequency of pulsed microwave signals. On the other hand, while transfer oscillator frequency counters can measure the frequency of pulsed microwave signals they have limitations in measuring signals with large frequency modulation components. The present invention utilizes analog microwave frequency dividing devices to virtually instantaneously convert the signal to be measured in octave steps into the frequency regimes associated with digital frequency counters. The apparatus disclosed comprises an antenna or other device for receiving a microwave frequency signal and feeding it to an analog frequency divider system having n stages, where n is an integer, each stage dividing frequencies applied to it by a factor of 2.

Abstract: Novel bis cyclic ureas are disclosed having the formula ##STR1## wherein C.sub.n H.sub.2 n represents alkylene from 4 to 12 inclusive and provided there are at least 4 carbon atoms in succession in the chain and R is the residue obtained by the removal of both halogen atoms from a diacid halide.The bis cyclic ureas are easily converted to a novel class of aliphatic diisocyanates simply by heating. Alternatively, they are blended with polymeric polyols to form one-component storage stable compositions which are thermally converted to polyurethane resins without any significant volatile or side product formation.

Abstract: An outdoor hunting blind shelter which is completely portable, all weather, and compact is an inflatable single unit hunting blind and a camper's restroom facility combined, furnishing features consisting of walls and roof which are supported by hollow, tube-type ribs forming a framework all of which are made of vinyl plastic. The hollow, vinyl plastic ribs are inflated with air through an air valve located in the foundation rib. The walls and roof are of thin plastic vinyl material joined to the ribs, and they feature an opening for entry and departure in one wall of the shelter. Windows for viewing and firing firearms are provided in the other walls. Support tie-off loops are located at each corner top and bottom of the shelter for extra support if needed. Restroom facilities include both shower and tub combinations.