Abstract: An improved droop stop for a fully articulated helicopter rotor is provided herein curved mating surfaces are employed between the spindle pad and the centrifugal droop stop static support arm to provide surface rather than line contact therebetween during centrifugal operation. The centers of the curved surfaces are coincident at the pivot point of the droop stop centrifugal arm to force the downward load of the blade to pass through this pivot point.

Abstract: An analog optical processor which performs complex transform operations or omplex correlations to yield quantitative (numerical) output. This is accomplished on data points which are used as inputs serially or simultaneously. The dynamic range of the input function that may be operated upon is not limited, as heretofore, by the characteristics of a medium on which the input function is recorded or stored. The dynamic range of the output is also not limited by the characteristics of a discrete electro-optical sensor.

Abstract: Fabrication of unoriented phase I crystalline PVF.sub.2 is described wherein commercially available PVF.sub.2 phase II (crystalline form) is placed in a high pressure cell and its temperature is raised slightly over its melting point. The sample is then subjected to abrupt changes in high pressure and the temperature is dropped thereafter. The pressure is then reduced resulting in a product which contains both phase I and phase II forms of PVF.sub.2. The phase I content of the product varies from a few percent and up depending upon the pressure applied during the quenching step.

Abstract: A down link UHF antenna is designed which includes four equispaced arms ml plated at an angle on a fiberglass cylinder. A coaxial connector is connected to each of the four arms with the metal plated inner surface as the common ground.

Abstract: A plasma-spray technique using rapid temperature quenching transforms commercially available .beta.-rhombohedral boron in powder form into thick, dense wafers of crystalline .gamma.-tetragonal boron.

Abstract: A process is described for the polymerization of cyclic olefins by ring-opening employing a coinitiator such as acetylene or substituted acetylenes. The polymers obtained by this method are highly stereoselective.

Abstract: PZT/polymer composites and a simplified method of their fabrication are dribed. Commercially available PZT Pb(Zr, Ti)O.sub.3 powder is thoroughly mixed with a binder such as polyvinylalcohol and polymethyl methacrylate (PMM) spheres and pressed into pellets. The binder and PMM spheres are burnt out by heating pellets slowly and the porous pellets so obtained are sintered by heating them in closed high-purity alumina crucibles and lead zirconate as a source of lead is added thereto. The highly porous pellets thus obtained are impregnated with a suitable polymer such as silicone rubber elastomer or vinylcyclohexene dioxide epoxy.

Abstract: The present invention concerns using star sightings to supplement the ineal instruments in nonfixed launch systems so as to provide increased accuracy without refinement of the inertial systems. It is particularly applicable to a system in which the missile is launched from a moving base of uncertain position. A stellar fix is obtained by pointing a sensor in the direction of a star, scanning the optical field of view through an elongated slit which is parallel to the pitch axis and centered along the missile roll axis, rotating the missile 90.degree. to interchange the pitch and roll axes and scanning again to establish another coordinate on the first star sighted and a single coordinate on a second star.

Abstract: A method and apparatus for using pressure changes to indicate volume chan in fluid level indicators or other devices with the required degree of sensitivity and accuracy is provided. A change in fluid volume is indicated by detection and display of a concurrent pressure change in a captive volume of air.

Abstract: An instrument having a logarithmic response is provided which continuously easures rates of rainfall over a range of from 0.3 to 350 mm/hr by determining the electrical power required to evaporate the water as it arrives on an exposed sensor. The sensor determines the flux of rain or cloud water arriving on its surface and consists essentially of a porous, water absorbent, dielectric material held between two metallic electrodes across which a fixed electrical potential is maintained. The water is evaporated by electrical heating as it arrives on the surface, and the amount of power required is a measure of the mass flux of water to the collecting surface.

Abstract: A balance system for rotating turbomachinery and other rotating devices is rovided wherein balance correction is obtained by snap rings having both an intentional eccentricity of their center of mass and discrete peripheral features which are adapted to be received in corresponding recesses in the machinery.

Abstract: A slow wave guiding structure such as a helix delay line for electron intction devices of the traveling wave type having diamond heat sink supports for substantial enhancement of power levels of operation is provided. The diamond supported helix structures are maintained in good thermal contact by pressure only in lieu of the diamonds being bonded to metallic members. The invention is applicable to numerous slow wave structures including ladder, ring-bar, meander, as well as interdigital types.

Abstract: Ammonia is utilized as a reversible plasticizer in the deformation of theplastic polyamides so as not to degrade the mechanical properties of the deformed material. It may be retained in the material under pressure and/or low temperature during extrusion or other deformation processes and is spontaneously released with time and at reduced pressure and/or elevated temperature at the end of the process, such as at the exit side of an extruder die.

Abstract: A device for preventing or substantially reducing lateral slippage of an ect which is held to the surface of another object by suction means is provided. Suction pads are mounted so as to allow conformation with irregularities of the supporting object's surface and are provided with prongs preferably made of sharpened tool steel which are oriented to dig into the surface to preclude lateral slippage during operation.

Abstract: A controller for achieving quiet operation of an AC motor utilizes an arrement of force-commutated, controlled rectifiers that are gated in a manner that results in the motor windings being energized with a preselected number of adjustable width, current pulses during each half cycle of the power supply. In the interval between pulses the motor winding is short circuited so that the motor current remains continuous upon commutation between the "on" and "off" states. The number of pulses are selected so as to reduce those magnetic field stress harmonics that are responsible for the excitation of vibration and noise.

Abstract: A device for rapidly securing and releasing a helicopter is provided. The vice effects positive haul down of an aircraft from a landing attitude above a landing pad aboard ship to a predetermined landing position on the pad, among other uses, through a plurality of rotatable spring-loaded over-center dogs clamped onto the free end of a haul-down cable and a sliding, cylindrical spring-loaded latching device which maintains the dogs in clamped relationship with the haul-down cable. The haul-down cable is instantly released upon freeing of the dogs.

Abstract: A parachute release arrangement which is mounted on the parachute buckle lizes a pair of water sensors that are activated when they are immersed in sea water. Activation of one sensor results in the connection of a battery to a DC-to-DC converter which raises the battery voltage to a substantially higher level for charging a storage capacitor. If the other sensor is also activated, this storage capacitor is subsequently discharged through an electrical explosive device when the voltage across it reaches a predetermined value. The resultant explosive force disengages a release lever in the buckle from the parachute strap and allows the detachment of the parachute. A checkout circuit is provided for monitoring the standby status of the control circuit.