Abstract: A land mine is provided with a pair of nested bowl shaped parts having their respective contacting surfaces arranged for tangential displacement relative to one another, and an actuating device provided in the mine is selectively responsive to such tangential displacement for activating the percussion mechanism in the mine. The actuating device includes a member located in a space provided between the contacting surfaces of the nested parts, and a locking device operates in response to the presence of a predetermined external force to lock such member to one of said parts to cause said member to activate the percussion mechanism upon occurrence of the tangential displacement between the parts. The locking mechanism is responsive to the absence of said predetermined external force for unlocking said member from said part to prevent activation of the percussion mechanism upon occurrence of said tangential displacement between the parts.

Abstract: A hollow structural member formed of thin sheet steel is formed with one or more longitudinal joints and the interior is filled with a rigid lightweight synthetic plastics foam such as polyurethane. Each joint includes folded lips or flanges which are designed to provide a restricted clearance or gap into which the foaming material penetrates and changes from a cellular to a non-cellular composition and also provides an adhesive bond at each joint and a moisture proof seal.

Abstract: A cathode ray tube meter, which may be developed as a VU meter, provides visual representation of the signal levels in each channel of plural signal channels. The signal channels may be the signal channels in a multi-channel audio system. The amplitude of a sawtooth waveform signal from a sawtooth waveform signal generator, which also controls the vertical sweep of an oscilloscope, is compared sequentially with individual d.c. signals developed by respective peak detectors, one being associated with each signal channel, to provide a control signal whenever the amplitude of the sawtooth waveform signal exceed the level of that particular one of the d.c. signals with which it is being compared at any given time. The control signal thus produced is used either as a blanking signal for the vertical sweep or as a signal for effecting the resetting of the sawtooth wave generator. A second sweep signal having a plurality of discrete levels controls the horizontal sweep of the oscilloscope.

Abstract: In an amplification system comprising an amplifier, a loudspeaker, normally open contacts connected in series between the amplifier and the speaker, and a power supply for the amplifier having relatively long buildup and decay times of its output voltage in response respectively to the connection and disconnection of the power supply to and from the a.c. line, means are provided responsive to the connection of the power supply to the a.c. line for delaying the closing of the normally open contacts until after the power supply voltage has built up to its full operating potential for eliminating the transient audio signals from the amplifier associated with power supply voltage buildup from being reproduced by the loudspeaker. Means are also provided for opening the contacts quickly after the power supply is disconnected from the a.c. line for eliminating the distorted audio signals from the amplifier associated with power supply decay from being reproduced by the loudspeaker.

Abstract: A superheterodyne f.m. receiver having a manually tunable local oscillator which is electronically voltage tunable over a small range, and including a frequency discriminator for providing signal voltage and a.f.c. voltage in response to a received f.m. carrier, wherein is provided an electronic bipolar switch responsive to either positive or negative a.f.c. voltage of greater than a predetermined value for effecting grounding of a point of an a.f.c. circuit which applies a.f.c. voltage to the local oscillator, and which also includes an interchannel noise detector which also provides grounding signal for that same point of the a.f.c. circuit.

Abstract: A radiation emitter for a projectile comprises a pyrotechnical charge located within the body of the projectile, and connected via a channel within the body to an opening in the side of said projectile to emit radiation via said opening when the pyrotechnical charge has been ignited. The radiation emitter may comprise the transmitter unit of a proximity fuze carried by the projectile.

Abstract: A vehicle brake system comprises an actuator which is hydraulically connected in parallel with a power booster between the master cylinder and wheel cylinders of a vehicle. The hydraulic connections include solenoid control valves normally operative to connect the power booster to the wheel cylinders and to disconnect the actuator from the wheel cylinders. The valves are responsive to electrical signals generated when vehicle skidding occurs to disconnect the power booster from the wheel cylinders, to connect the actuator to said wheel cylinders, and to supply a pulsating fluid pressure from the actuator to the wheel cylinders in place of the steady fluid pressure normally applied to the wheel cylinders from the power booster, thereby to stop the skid.

Abstract: A tube for sticking stripformed drains into the ground has a predetermined fixed profile of rhombic cross section made by pressing two opposite corners of a square tube towards each other.

Abstract: Apparatus for electrically measuring the water content of a specimen such as grain the electric resistivity of which has a correlation with the water content, comprising a linearizer for converting the measured electric resistivity in the low water content region in which the electric resistivity of a grain specimen changes non-linearly with the water content into an electric quantity linearly changing with the water content, and a temperature compensator including a temperature sensitive element for generating a linearly changing electric signal with temperature, the temperature compensator generating a temperature-compensating electric signal from said linearly changing temperature signal, the temperature compensation of the measured value being commonly done with said temperature compensator in both the low and the high water content ranges by adding a linearly changing electric quantity corresponding to the measured water content and the compensating electric signal.

Abstract: Apparatus for converting a single-phase power supply to multi-phase operation in which at least one phase of the multi-phase supply is generated by applying the single-phase to the input of a bridge network, each arm of which contains at least one switch device controlled by external circuitry to give an output waveform from the bridge network which contains a fundamental component of the single phase which is out of phase with the single phase by a predetermined phase angle. The output waveform may be filtered to eliminate unwanted harmonics.

Abstract: A dome loudspeaker including a yoke assembly consisting of a flat plate having an opening and a U-shaped member having its arm ends secured to the flat plate, a cylindrical magnet being secured to the cross arm of the U-shaped member adhesively, the cavity formed by the U-shaped member being packed with fiberglass pads and sealed by end plates, a flexible dome being secured adhesively to a voice coil wound on an aluminum form and these being secured to a mounting plate, which is arranged to be precisely spatially related to the yoke assembly, with intervening padding of fiber-glass to provide damping, the dome being covered with a perforated cover separated from the dome by a fiber-glass pad.

Abstract: An apparatus for joining a pair of sheets includes mechanisms for cutting patterns of plural partial perforations in the sheets, applying an adhesive material to at least one of the sheets, transporting the partially perforated sheets in spaced relation to one another with the pattern of partial perforations in each sheet being in opposed relation to the pattern of partial perforations in the other of said sheets, and bending the tab areas defined by the partial perforations in said sheets through an angle of substantially 90.degree. to the plane of each sheet and in a direction extending toward the other sheet to cause corresponding pairs of said tabs to come into overlapping, planar engagement with one another in the region between said spaced sheets and to be bonded to one another by the adhesive material.

Abstract: Anti-snow and anti-ice protection for horses hooves in which an insert is provided in the horse-shoe and part of the elastically deformable U-shaped insert conforming to and coextensive with the inside edge of a horseshoe and in resilient engagement with the sole of a horse's hoof is partly clamped between the horse-shoe and the sole of the hoof.

Abstract: A pair of paper board panels are joined together by means of a seam structure comprising interlocking portions of the two panels. The first panel has a plurality of spaced partial perforations which define the plurality of flat first tabs each of which is displaced away from one side of the first panel about a hinge line in the first panel. The second panel is provided with a plurality of second tabs along one edge thereof each of which has a relatively narrow neck flaring outwardly into a wider tip portion. The second tabs are inserted through the partial perforations with the free ends of the second tabs being disposed adjacent the hinge lines of the first tabs, and with portions of the second tabs extending beyond the edges of their associated partial perforations to overlie the first panel on the side thereof adjacent the first tabs.

Abstract: A plug receptacle for receiving an adaptor designed for insertion into an electrical contact rail comprises a metallic base plate having a pair of metallic arms affixed thereto and extending in spaced facing relation to one another outwardly of said plate. A central insulator member is attached to the base plate between the arms, extends from the base plate toward the spaced free ends of the arms, and cooperates with the portions of the arms outward of the free end of the insulator to define recesses which are complementary in shape and dimension to the opposed supporting clips of the adaptor. The insulator member includes a central opening in alignment with the space between the free ends of the arm, and supports a pair of electrical conductors which face said central opening and which are positioned for engagement by opposed electrical contacts of the adaptor when the adaptor is inserted between the free ends of the arms and rotated to turn the adaptor supporting clips into the recesses.

Abstract: A knitting machine is provided with a plurality of positive feed devices for feeding yarn from a plurality of yarn packages to a plurality of feeding stations. The positive feed devices comprise a plurality of rotatable rollers associated with a driven tape running along the surfaces of the rollers and having a width less than the axial dimension of each roller, and a yarn guide comprising a bracket having eyelets to guide the yarn is mounted for free pivotal movement adjacent each roller to position a length of yarn onto the tape for positive feeding or to displace the yarn away from the tape for nonfeed thereof. The position of the yarn guide is controlled by one or more weights which are attached to the bracket at positions displaced from the bracket pivot point to urge the bracket and its eyelets into the nonfeed position under the influence of gravity.

Abstract: A two-stroke switch to be actuated by two stroke operations comprises a first stationary terminal, a second stationary terminal, a contact element of conductive elastomeric material for establishing a current path between the first and second terminals, and an actuating member provided with a moving terminal for imparting a compressing force to the contact element. When the actuating member is first manipulated to compress the contact element axially thereof, the contact element is rendered electrically conductive, and when the actuating member is secondly manipulated to further compress the contact element which is then enlarged radially thereof, the contact element may be electrically connected to the first and/or second terminals thereby turning on the switch.

Abstract: An envelope for photographic prints includes a low-cohesion polished surface portion supporting a plurality of removable, adhesively-backed tabs thereon. The level of adhesion between the adhesive and backing paper portions of each tab is greater than the level of adhesion between the adhesive and the polished surface portion of the envelope but less than the level of adhesion between the adhesive and photographic print paper, whereby each tab may be removed from the polished surface portion, its adhesive layer may then be applied to the back of a photographic print, and the backing paper portion of the tab may thereafter be removed to transfer the adhesive layer from the tab to the photographic print back to permit the photographic print to be mounted in an album or the like.

Abstract: A charge coupled device in which a row of electrodes is deposited over an insulating layer on a substrate has clocking pulses applied to some electrodes for clocking charge packets from source to drain gates and a steady or long pulses applied to other, tapping, electrodes. Amplifying circuitry connected to each tapping electrodes non-destructively measures the change in capacitance under the tapping electrode as a charge packet passes under it.

Abstract: A jack is provided in which a movable contact is driven away from a fixed contact upon insertion of a plug and returns into abutting relationship with the fixed contact upon withdrawal of the plug. The movable contact comprises an electrically conductive, rigid body which is rotatably mounted at its one end, and is biased toward the fixed contact by means of a coiled spring. When the plug is inserted, the movable contact is displaced against the resilience of the coiled spring to move away from the fixed contact, while when the plug is withdrawn, the resilience of the coiled spring urges the movable contact into abutting relationship with the fixed contact.