Abstract: A radiant energy detector having a pair of receiving transducers, a pair of ariable gain amplifiers connected to said transducers for amplifying the outputs thereof different amounts, a subtract circuit for producing a signal representing the difference of said amplifier gains, a Schmitt trigger which is triggered by said difference signal whenever it exceeds a predetermined value, and an And gate connected to the outputs of said pair of amplifiers and the output of said Schmitt trigger for producing a utilization signal whenever all thereof occurs simultaneously.

Abstract: A mine neutralization system having self-propelled explosive charges fired t submarine mines by a mine detection and fire control system.

Abstract: A detector of electrical wires which aer partially submerged in water and rtially extend out thereof having a means for broadcasting electromagnetic energy to the underwater portion thereof and means for receiving electromagnetic energy from the out of the water portion thereof.

Abstract: Disclosed is a sound source which will broadcast predetermined frequency ustical energy throughout subaqueous environmental mediums. It includes a housing body of cylindrical configuration with elongated slots located at uniform distances around the periphery thereof. A flexible, resilient sleeve surrounds said housing in such manner that it forms a movable diaphragm over each of said slots. By means of a pressure control system, internal gas pressure within said housing body may be regulated to make it less than the pressure of the subaqueous medium external thereto, thereby pulling said diaphragm inwardly through said slots. A plurality of motor driven rollers roll around the inside surface of said housing and contact the inside surface of said flexible sleeve, thereby pushing it in an outwardly direction back through said slots, so as to displace some of the subaqueous medium adjacent thereto.

Abstract: An unmanned, self-propelled minesweeping apparatus, capable of sweeping at ubstantial depths, is described, comprising a torpedo-like submarine vehicle that deploys and tows a string of explosive mooring cable cutters terminating in a sea anchor. The sea anchor serves as a carrier for the cutters and the towline and, after ejection as a package from the vehicle, is actuated to an expanded condition and displaces the cutters and coils of towline therefrom.

Abstract: Electronic intervalometer circuitry utilizing a combination of mechanically ctuated switches and solid state logic components to carry out a predetermined program of deployment and sequential detonations of a plurality of underwater explosive charges.

Abstract: A power supply has the source and drain of a MOSFET arranged for connection etween an input voltage source and a load. In normal operation a bias voltage is applied to the gate to place the MOSFET in a conductive state. A difference amplifier maintains a fixed ratio between a reference voltage and the output voltage. Current limiting circuitry senses the current that the power supply provides to the load and disables the MOSFET when the current provided to the load exceeds a predetermined value. Thermal shutdown circuitry senses the operating temperature of the power supply and places the MOSFET in a nonconductive state when the operating temperature exceeds a predetermined value.

Abstract: A water fillable chute, to be employed as a submerged tractor device is cected to a plurality of wire severing grapnels by means of a metallic chain for sweeping command type river mines.

Abstract: An electroacoustic transducer having a truncated hemispheric propagation or esponse pattern is disclosed. The transducer comprises an assembly of fish-bone shaped piezoelectric elements, each characterized by a plurality of rod portions extending from a spine portion. The assembly is pivotally mounted within a liquid filled acoustic window means.

Abstract: A sonar system is disclosed having signal analyzing circuitry rendering the ystem responsive to objects of a predetermined size. The signal analysis is accomplished by a spectral analysis of the echo signals returned from the objects. In particular, the relative height of adjacent side lobes of echo signals energy returned to the sonar are compared to indicate the size of the object reflecting the signal.

Abstract: A sonic echo simulator for simulating sonar signals reflected from underwr targets having a transmitter which broadcasts sonar signals through a given amount of water toward a receiver for readout thereat. Prior to broadcast, various characteristics, such as target length, target aspect, target shadow length, range to sea floor, sea floor reverberation, and target highlights are selectively incorporated into said broadcast sonar signals by combined circuits for the timely generation thereof, respectively.

Abstract: A high information rate catacoustic system having a sonar transmitter dised at a remote location from and facing a sonar receiver in such manner that forward-scattered echoes of sonic energy originally broadcast by said transmitter are reflected by and received from the sea floor by said receiver and displayed by a recorder connected thereto as an inverse function of the range from the sea floor to said transmitter.

Abstract: Disclosed is a system for locating a wire that is partially submerged wit water and partially extends out thereof which includes a transmitter for broadcasting radio frequency electromagnetic signals, a phase gradiometer for receiving said radio frequency electromagnetic signals after they have been received by that portion of said wire that extends out of said water and re-radiated by that portion of said wire that is submerged therein and for timely producing a pair of output signals in response thereto, a pair of constant output amplifiers for processing said pair of gradiometer output signals to identical useful levels, a phase comparator for determining the phase relationship between said pair of processed output signals, and a readout for indicating said phase relationship. The aforesaid phase gradiometer may be housed in a probe-type of mobile underwater vehicle which is towed by a tractor vehicle in such manner as to cause said phase gradiometer to traverse an underwater course in search of said wire.

Abstract: Disclosed is an acoustical energy generator having a venturi front section o which is attached a pair of rear tail pipes. A pair of return flow manifolds are respectively connected between said rear tail pipes and said front venturi section at such locations that the static pressure in the former are greater than the static pressure in either of the latter when a fluid is flowing therethrough. Controllable valves are optionally disposed in said return flow manifolds to regulate the fluid flow therethrough, and a freely rotatable flutter valve may be disposed at the common junction of said venturi section and tail pipes to facilitate the rapid transfer and/or cutoff of flow from the former to both of the latter in an alternating manner, and thereby effect a more positive generation of cavitation at a desired frequency of operation. A bridle is connected to the front end of the venturi section and a tractor vehicle is attached thereto by means of a tow cable.

Abstract: A sweep device for river mines of the command type is described. The device mploys two spaced, parallel blades which support the sweep device on the bottom of the river as it is towed therealong. The blades constitute laminated cutting elements which provide a signal of the presence of a command wire as it is severed on contact, as well as serve as electrodes for supplying an electric signal to sweep the mine. An electrical circuit is also described to process the signals from the blades, so as to distinguish between small metallic debris and metallic bodies bridging the two blades.

Abstract: A lane marker preferably for delivery by a CATFAE weapon, has a mechanical imed device which is positioned and rides in the rear section of the CATFAE weapon as it is launched to a specified position on the ground. At first contact of the CATFAE with the ground, the lane marker is ejected vertically a short distance away from the ground and then falls onto the ground. On the ground the lane marker attitude is controlled for effective employment. Spring-biased probes deploy the makers which typically comprise two flags and two chemiluminescent lights to mark the impact point of the CATFAE. The two chemiluminescent lights are activated mechanically by cloud detonation overpressure prior to deployment of the spring-biased probes.

Abstract: A mine sweeping method and related apparatus for achieving at least tempoy passivation of underwater acoustic influence mines, by the generation of particular underwater sounds of progressively increasing intensity. The water is by repetitively injecting into the water individual metered slugs of heated water, which water is heated to its saturation pressure but below the critical point. The metered slugs of heated water may be of the same or of progressively increasing size, i.e. weight, and can be released from a heated pressure chamber into the water from either a stationary array or from an array towed from a moving ship, and at a depth such tht the expanding bubbles, produced by the change of state of the heated water, do not break the water surface. The rapid expansion of the metered slugs produce the desired sound output for temporarily rendering the acoustic influence mines passive by actuating their anticountermine circuits.

Abstract: The echo ranging system of the invention comprises circuit means to diffetiate between shadows cast by objects and the period of time prior to the receipt of the first bottom return, as well as the lack of bottom reverberation for other reasons. Additional circuit means determines if the length of the shadow signals in comparison to their range exceeds a predetermined value. Circuit means are also included to produce a first electrical signal when such shadow signals are received. Further circuitry analyzes the shadow signals for which the first electrical signals were provided and produces a second electrical signal when said object shadow signals exceed in number or length a predetermined value. Additional circuit means are provided to convert said first and second electrical signals to suitable audible signals which may be readily distinguished, one from the other.

Abstract: This invention pertains to the electroacoustic transducer arts and disclo an improved physical construction therefor in which a honeycomb-like member is used to secure both pressure release and thermal transfer for the converting element.

Abstract: Dineopentylcadmium is prepared from cadmium dihalide and neopentyl Grignard in tetrahydrofuran. The reaction product is isolated by addition of dioxane, filtration, removal of solvent via distillation, and purification by sublimation.