Showing papers by "General Dynamics published in 1979"

Composite tape laying apparatus including means for plural longitudinal and transverse cuts

Abstract: An apparatus for severing and laying composite tape to form structural members with a shearing and compacting mechanism capable of a large variety of angular or circular severances. The severances are formed incrementally or digitally with a number of lengthwise slits of selected length. A plurality of transverse cuts are formed in the tape to intersect the slits to form a stairstepped severance. A curved chute at the discharge end of the apparatus has an endless belt to maintain the tape in alignment as it is pressed onto the work surface. The tape is compacted onto the work surface by a segmented roller system composed of several individual rollers. As the severance is reached, the rollers are selectively and individually disengaged from the work surface to correlate compaction termination with the shape of the severance.

Fastener incorporating ultrasonic transducer

Abstract: A threaded bolt having an opening in either its head or its opposite end with an ultrasonic transducer fixedly secured therein for use in obtaining preload measurements as well as other measurements for quality control inspection or for monitoring purposes.

Smooth spline-like finite-element differentiation of full-field experimental data over arbitrary geometry

Abstract: A new smooth two-dimensional numerical method is presented for representing and differentiating discrete fullfield experimental information. The method involves minimizing a positive definite functional by use of finite-elements to ‘best-fit’ the data. Experimental data points may occur in any configuration, boundary derivatives need not be specified, and arbitrarily shaped regions can be handled readily. The method is demonstrated by photomechanical strain analysis.

Electronic engine control

Abstract: An electronic controller for an internal combustion engine provides a ratio control signal corresponding to a respective air/fuel ratio, and responds to an air flow signal, a fuel flow signal and the ratio control signal to control fuel flow as to make the ratio of air flow to fuel flow substantially equal to said respective air/fuel ratio. The ratio control signal is developed from a base run ratio control signal as modified in response to various parameters such as engine temperature, manifold pressure, idle, manifold vacuum, fuel temperature, wide open throttle, engine speed, and start. The controller also provides a speed-up circuit for promptly responding to change in air flow and dynamic braking for the fuel metering pump. The pump speed circuit includes a range extender. The controller further provides a timing advance control signal in response to air/fuel ratio and various engine parameters such as engine speed, manifold pressure, throttle position, engine temperature, air temperature, air/fuel ratio, and start.

Multi-spectral detection system with common collecting means

Abstract: A multi-spectral detection system for detecting radiation within frequency bands that are in diverse portions of the electromagnetic spectrum is disclosed. The preferred embodiment is a Cassegrain system including a primary reflector for reflecting radiant energy in the radio frequency and infrared portions of the electromagnetic spectrum; a subreflector positioned along the axis of the primary reflector for re-reflecting the radiant energy reflected from the primary reflector toward the primary reflector and focusing the re-reflected radiant energy in a common focal plane about the system axis; a feed horn coaxially positioned at the common focal plane and having an entrance in the common focal plane about the system axis for transferring the collected radio frequency radiant energy from the focal plane to a detector of radio frequency radiant energy; and a bundle of optical fibers coaxially positioned at the common focal plane and having openings in the common focal plane about the system axis for transferring collected infrared radiant energy from the focal plane to a detector of infrared radiant energy. A baffle is coaxially positioned for blocking light other than the re-reflected infrared radiation from being received and transferred by the optical fibers.

Nucleation, growth and transformation of amorphous and crystalline solids condensing from the gas phase

Abstract: The condensation of solids was investigated from the initial nucleation stage through continuous film growth, using evaporation and high-energy ion-beam sputtering. At all stages the kinetics of the nucleation process and the structural characteristics of the condensed phase (glassy, polycrystalline and monocrystalline) were defined. Although many condensates were explored, the specific system discussed is germanium condensing on a variety of amorphous and crystalline substrates. The kinetic behavior observed in crystalline deposits was found consistent with the accepted atomistic model for nucleation. This allowed determination of such nucleation parameters as: the activation energies of surface diffusion,Q d and adsorption,Q ad ,the critical nucleus size,n *, and others. Values of such parameters were found to be systematic functions of the kinetic energy and flux of incident particles and of the type and temperature of the substrate. Two flux and temperature dependent structural order transitions were observed in the very initial nucleation stages and found to coincide with corresponding transitions inn *. Correlation was also established between these transitions and two structural transitions occurring during continuous film growth. This was aided by the occurrence of all four transitions in intermediate condensation stages, i.e. prior to coalescence of nucleation clusters into continuous film. All results were very distinctly affected by the vapor state of the adsorbates, implying considerable correlation between condensation on solid surfaces and in a vapor.

Electrostatic fiber optic scanning device

Abstract: Disclosed is an fiber optic scanning device that includes an optical fiber of predetermined length having one unsupported end for scanning, and having another end rigidly supported in a cantilevered fashion. The disclosed device operates to allow the movable end to be positioned with voltages that are substantially reduced over the prior art. To that end, an electrically conductive film lies on the fiber extending from the unsupported end to the supported end; and a transparent conductive plate lies in a plane perpendicular to the length of the fiber spaced apart from the unsupported end. This conductive plate forms a capacitance C with the conductive film. A voltage source V couples between the transparent conductive plate and the conductive film on the fiber to produce an electrostatic charge Q on the movable end of the fiber, where Q=VC. The movable end is positioned with a force F=QE by generating an electric field E transverse to the length of the fiber.

Method for assembling large space structures

Abstract: An automated assembly, maintenance, and repair system for the construction of a large space structure. The space structure comprises a plurality of trusses and truss junctions that in turn are made up of a plurality of individual struts and nodes. The truss assemblies are progressively built by an assembler trolley as the trolley crawls along the constructed truss. The trolley comprises a forward crawler and a rear crawler joined by an articulated coupler. The crawlers are carried along the structure by belt transports incorporating grippers that engage the truss structure at the nodes. Manipulator arms for strut and node assembly are located on the forward crawler, and the majority of control, power, and communication systems are located in the rear crawler. Cargo canisters filled with component parts for constructing the space structure are carried by the forward crawler. The space structure configuration is determined by the arrangement of the individual struts and nodes during the assembly process.

Method for vacuum lamination of flex circuits

Abstract: A vacuum laminating fixture includes a pair of opposed plates having opposed plane faces with a peripheral groove formed in each plate surrounding the face with the grooves matched for receiving a unitary band seal extending between the grooves for sealing the space between the faces of the plates, a vacuum port is formed in the lower plate communicating with the area of the face inside the peripheral groove. The method includes setting up a laminate of plural flexible sheets of circuit, placing the laminate within and between the faces of the plates, drawing a vacuum of 28 inches of mercury for a period of two minutes to completely evacuate the space between the laminate sheets, and thereafter applying a predetermined curing pressure and temperature to the plates within a press.

GaAs MESFET demodulates gigabit signal rates from GaAlAs injection laser

Abstract: This letter describes the experimental results of an optical transmission link with modulation rates up to 4 GHz. The transmitter consists of an FET driven GaAlAs injection laser emitting at a 8500 A wavelength. The receiver makes use of a GaAs MESFET chip which is compared with a standard silicon avalanche photodiode demodulator.

Fin erection mechanism

Abstract: A plurality of fins for a missile which are capable of being folded to conform to the general cylindrical contour of the missile body and which are biased to unfold to an erect position and which includes an interconnection mechanism for connecting all the fins together to ensure simultaneous erection and for distributing the erection moment of individual fins to all fins; said interconnection means further being capable of acting without interfering with the movement of the fins for flight control without need for disengagement after erection.

Fastener incorporating removable ultrasonic transducer

Abstract: A threaded fastener incorporating a removable ultrasonic transducer for obtaining preload measurements as well as other measurements for quality control inspection or for monitoring purposes. The transducer may be removed for repair or replacement purposes.

Model error sensitivity suppression: Quasi-static optimal control for flexible structures

Abstract: Model Error Sensitivity Suppression (MESS) provides simultaneous solution for two control problems inherent to flexible spacecraft control: a dynamic problem-modal stabilization, and a static problem modal decoupling. The (MESS) algorithm is developed in simplified form to illustrate the decoupling properties of the alogirthm. An example is presented that highlights an interesting property of the algorithm; namely, the determination of the directions of the column vectors of the optimal gain matrix, a priori, before solution of the Riccati equation. Similar results hold for dual estimator design. These static decoupling properties of the algorithm allow reduced-order estimating and decentralized control.

Method and apparatus for accelerating a solid mass

Abstract: Method and apparatus for accelerating an axi-symetrical mass, such as a projectile, (50) by imploding a plasma discharge against the projectile surface, the plasma inducing an ionized liquid layer, and a magnetic field from the plasma interacting with the ionized liquid layer to accelerate the projectile. In a preferred embodiment the projectile is tapered toward its axis in a direction opposite from the direction of acceleration. To provide a long acceleration path a plurality of cascaded accelerating sections (51-55) are provided along the path and the projectile position, as it advances between the sections, is sensed and discharges are switched on sequentially in the sections.

Circulator in a stripline microwave transmission line circuit

Abstract: A circulator in a stripline microwave transmission line circuit that is disposed in a pattern of printed circuit conductors between a pair of facing dielectric material circuit boards having conductive ground planes on their exposed broad faces. The circulator includes three printed circuit center conductors disposed between the two boards in a symmetrical array extending radially from a circular hole aligned through the two boards; a conductive foil having a central portion concentrically disposed within the perimeter of the hole and three radially projecting arms arranged in contact with the radially extending center conductors; a pair of pucks of ferrite material of a predetermined size selected to provide circulation of microwave signals of a predetermined wavelength concentrically disposed in the hole on opposite sides of the conductive foil; a pair of conductive covers in contact with the ground plane conductors and extending to completely enclose the ferrite pucks within the hole; a pair of magnets disposed on opposite sides of the boards in axial alignment with the ferrite pucks for providing a magnetic field through and normal to the central portion of the conductive foil; magnetically permeable material contacting the magnet and concentrically disposed for providing a closed magnetic loop for shielding the circulator; and a pair of high dielectric material rings disposed in the holes for radially enclosing the pucks and making contact with both the pucks and the surfaces of the board defining the holes, wherein the radial thickness of each ring is one-quarter of the predetermined wavelength for impedance matching the circulator to each of the transmission lines defined by the center conductors and the ground planes. The conductive covers are dished to have respective central portions that are recessed below the ground planes to broadly contact the ferrite pucks and maintain the ferrite pucks in contact with the conductive foil.

Structural strut and node for large space structures

Abstract: An automated assembly, maintenance, and repair system for the construction of a large space structure. The space structure comprises a plurality of trusses and truss junctions that in turn are made up of a plurality of individual struts and nodes. The truss assemblies are progressively built by an assembler trolley as the trolley crawls along the constructed truss. The trolley comprises a forward crawler and a rear crawler joined by an articulated coupler. The crawlers are carried along the structure by belt transports incorporating grippers that engage the truss structure at the nodes. Manipulator arms for strut and node assembly are located on the forward crawler, and the majority of control, power, and communication systems are located in the rear crawler. Cargo canisters filled with component parts for constructing the space structure are carried by the forward crawler. The space structure configuration is determined by the arrangement of the individual struts and nodes during the assembly process.

Vacuum curing tool for composite materials

Abstract: A vacuum tool for a vacuum bagging curing operation comprising a base on which is placed a one piece vacuum bag comprising a top sheet with a peripheral sealing means attached thereto which cooperate to seal the bag in a zipper-like fashion, thus enclosing workpiece therein for the vacuum curing operation. A vacuum manifold is attached to the base to connect the tool to a vacuum pump to create a vacuum between the base and bag.

Three-dimensional measurement of radiant energy scattering characteristics with a turntable-type scanning interferometer

Abstract: A method and apparatus for measuring radiant energy scattering characteristics of a test panel of dielectric material over a sphere are disclosed. The test panel is supported on a turntable at a position on the axis of the turntable. The turntable has a first antenna radially mounted thereon for rotation therewith and directed toward the position of the supported test panel. A second antenna is mounted for selective positioning along a circular arc within a plane that includes the axis of the turntable, which arc extends at least ninety degrees from said axis, wherein the second antenna is radially directed toward the position of a test panel that is axially supported on the turntable at all positions along said arc. The test panel support is rotated with respect to the turntable to selectively position the test panel at a predetermined incidence angle with respect to the first antenna. The turntable is rotated with respect to the second antenna to selectively position the test panel at an angle with respect to the axis of propagation of the second antenna that is equal to and opposite the predetermined incidence angle. Radiation transmitted between the first and second antenna is measured with the test panel in the supported position at each of a plurality of predetermined equal and opposite incidence angles with respect to the first and second antennas; and radiation transmitted between the first and second antennas is measured at each of the plurality of predetermined incidence angles when the test panel is not supported on the turntable. The second antenna is position at a plurality of positions along the circular arc at various ones of the predetermined incidence angles at which measurements are made as described above. Further measurements are made, both with the test panel in its supported position on the turntable and with test panel absent, of the radiation transmitted between the first and second antennas at the plurality of positions along the circular arc at the various ones of the predetermined incidence angles. The reflectance characteristics of the test panel are then determined by subtracting the measurements taken without the test panel in place from those taken with the test panel supported on the turntable.

Bumped Tape Automated Bonding (BTAB) Practical Application Guidelines

Abstract: A number of mass bonding techniques have been used to replace wire bonding in hybrid microcircuit (HM) fabrication, but none has approached universal acceptance. In recent years tape carrier technology, typically called tape automated bonding (TAB) has received considerable attention. A more recent development, bumped tape automated bonding (BTAB), maintains the advantages of conventional TAB, offers some unique features of its own, and can be quite compatible with conventional aluminum-metallized integrated circuit (lC) chips. The present status of BTAB technology from the standpoint of practical HM fabrication and performance is presented.

Heat sink/fluid-to-fluid mechanical coupling of spacecraft coolant systems

Abstract: A spacecraft modular system with two components of a cooling system, one in each replacement hardware module and one in the satellite station, with a coupling means in the replacement module in the form of heat sink which collects heat from the heat generating hardware in the replacement module. The heat sink incorporates heat sink fins which interdigitize with coolant tubes in the satellite coolant system and make a mechanical interface with the fins in response to the satellite coolant system pressure for a thermally efficient heat exchange from the replacement module to the satellite coolant system. In another embodiment, replacement module coolant tubes interdigitize directly with the satellite coolant tubes in a fluid pressure responsive thermally efficient mechanical contact to provide a fluid-to-fluid mechanical coupling. The satellite cooling system is arranged in subsystems to isolate the coupling means from the remainder of the satellite cooling system to permit coupling and decoupling of selected modules without disturbing the remainder of the cooling system. Also involved is a method of forming a compound bend for the interdigitizing tubing arrangement of the second embodiment.

Common aperture dual mode seeker antenna

Abstract: The disclosed common aperture seeker antenna includes a parabolic array of crossed dipoles. This array is substantially reflective for radiated electrical signals in one band, and substantially transmissive for radiated electrical signals outside of that band. A monopulse (four-element) waveguide feed is rigidly positioned on the concave side of the parabolic array at the focal point thereof. The parabolic reflector antenna operates in the one band to provide a high gain active system for accurate tracking of targets. A planar spiral antenna is rigidly positioned on the convex side of the parabolic array in axial alignment with the parabolic reflector antenna. This wideband antenna operates over a multioctave frequency band below that of the one band to provide a low gain system for passive tracking of targets. The two antenna systems coexist in such a manner that each utilizes the available aperture to its fullest extent.

Finestructure in the spectra of GaAlAs heterostructure lasers

Abstract: An experimental setup allowing high resolution measurements to be performed on the emission lines of injection lasers is described. Axial and transverse mode laser structures can be observed as they change under dc input current variations and modulation signal influence. A resolution limit of 80 MHz is obtained. Results show a new finestructure ripple on the emission lines of GaAlAs heterostructure lasers which is distinct from the transverse mode structure. Axial mode amplitude limiting and simultaneous spectral widening are observed with increasing laser drive currents.

Fastener grip length measuring system

Abstract: A totally portable, hand-held measuring device utilizing an insertable sliding probe to measure material or structural part thicknesses. The position of the probe actuates electronic circuitry which digitally displays the grip length of the fastener to be selected. The device provides a fast and accurate means of determining the fastener with the correct grip length for each assembly.

Discretely positioned magnetic fiber optic scanner

Abstract: Disclosed is a magnetic fiber optic scanner which includes a flexible optical fiber of predetermined length, having one end fixedly supported in a cantilevered fashion, and having an opposite end that is unsupported and free to move. A magnet is rigidly mounted on the fiber near the unsupported end to there produce a magnetic dipole moment parallel to the length of the fiber. A grid like array of electrical conductors lies in a plane that is perpendicular to the fiber and is spaced apart from the unsupported end. By passing current through selected ones of the conductors, localized magnetic fields are produced that react with the dipole moment to position the unsupported end of the optical fiber in offset alignment with the selected conductors.

Double fabric, retractable, self-erecting wing for missle

Abstract: A retractable, self-erecting wing for a low speed missile, having a double walled fabric body held in extended position by spring loaded struts, the fabric enclosing an air pocket which acts as a damper to prevent the wing from fluttering under certain aerodynamic conditions. The wing is extended by a hinged strut structure and folds into a very small space adjacent the outer wall of the missile body. The structure enables a large area wing to be stowed in a minimum of space so that the maximum internal volume is available for payload. In stowed condition the wing is completely enclosed in the body for minimum drag during any high speed portion of the missile flight, multiple wings being released when required by a simple mechanism.

Toggle latch opening and closing tool

Abstract: The improved tool of the present invention is adapted to open and close efficiently and rapidly at least two types of widely used container toggle latches, one type having a latch handle in the form of a flat tongue and the other type having a hollow, generally tubular, open-ended latch handle. The improved tool comprises a generally L-shaped shank formed of first and second diverging legs integrally joined together at one end, and a handle secured to the free rear end of the first leg. The second leg, which is generally vertical in usual use, depends from the generally horizontal front end of the first leg; and the free end of the second leg is configured into a spaced, generally vertical pair of tines of unequal length. The shorter tine is closer to the handle. The handle may be large to readily fit the hand. The legs are generally flat and vertically oriented, with the first leg longer than the second leg for improved leverage when operating the tool. The upper end of the space defined between the tines may be rectangular for better gripping of the latch tongue, and the upper margin of the juncture between the legs may be sloped to facilitate prying with the tool. The tool is inexpensive, durable, safe and highly efficient.

Method of crosslinking aromatic thermoplastic polymers using a biphenylene terminated compound

Abstract: A method of increasing the strength and high temperature resistance of aromatic thermoplastic polymers by adding thereto an appropriate amount of certain biphenylene terminated compounds, then heating the mixture to a crosslinking reaction temperature. The biphenylene additive has been found to function as a plasticizer for the polymer, making it easier to work, mold, extrude, etc. prior to the heating step.

Differential games with noise-corrupted measurements

Abstract: In this paper, readily computable strategies for zero-sum, linear-quadratic differential games with noise-corrupted measurements are developed. Of particular significance is the fact that the governing differential equations no longer require the solution of an often difficult nonlinear, two-point boundary-value problem, but again satisfy the separation principle of linear-quadratic optimal control. The implications of the payoff relationships are considered.