Abstract: A speed control device characterized by a reference speed shaft spatially related to a heavy duty shaft, a drive train for driving the reference speed shaft at a constant angular velocity, a drive train for driving the heavy duty shaft at a variable angular velocity and a speed control assembly for continuously comparing the angular velocity of the heavy duty shaft with the angular velocity of the reference speed shaft, and a brake assembly connected to the heavy duty shaft adapted to respond to errors in the angular velocity of the heavy duty shaft for reducing the angular velocity of the heavy duty shaft to that of the reference speed shaft.

Abstract: A method and apparatus for cutting a transverse slot about a bore of smaller diameter than that of the slot are disclosed. The invention consists of introducing a cutting head facing transversely to the bore, through the bore opening its distance from the mill shaft being progressively extended by the addition of spacers between the head and the shaft until the desired slot depth is obtained. The spacers are held in position by a cable passing from the cutting head through the series of spacers and out along the mill shaft. The mill shaft carrying the cutting head is moved transversely into the object wherein the slot is being cut as the object is being rotated thereabout by the mill table to which it is affixed.

Abstract: An improved cryostat for use in a low or a substantially gravity-free environment adapted to cool an experiment through the use of helium II, or helium in its super fluid state. The cryostat is characterized by a plurality of interchangeable daughter dewars and helium supply or mother dewar having connected therewith a low pressure venting system for converting helium I contained therein to a super fluid state for use as a primary cryogen. Each daughter dewar is adapted to be removably mounted in mated relation on the mother dewar and is characterized by a support for an experiment package, a source of helium to be employed as a secondary cryogen, and a heat pipe suspended therefrom and adapted to be extended into the mother dewar for facilitating cooling of the secondary cryogen whereby a transfer of heat from the package to the primary cryogen, via the secondary cryogen, is accommodated as a film flow of helium II progresses from the heat pipe to the experiment dewar.

Abstract: A fire extinguishing apparatus delivering an extinguishing agent through a barrier surrounding a structure into the interior thereof. The apparatus includes an elongated tubular nozzle body which has a pointed penetrating head carried on one end of the tubular body. A source of extinguishing agent is coupled to the opposite end of the tubular body and is fed therethrough and passes through passages adjacent the head for delivering the extinguishing agent to the interior of the structure. A slidable mass is carried on the tubular body on a remote end of the tubular body from the penetrating head. By manipulating the slidable mass and bringing such in contact with an abutment the force imparted to the tubular body causes the head to penetrate the structure.

Abstract: A subcutaneous electrode structure particularly suitable for a chronic implant and for taking a low noise electrocardiogram of an active animal such as a rat, dog, monkey, cow or the like, comprises a thin inflexible, smooth disc of stainless steel having a diameter as of 5 to 30 mm, which is sutured in place to the tissue of the animal being monitored. The disc electrode includes a radially directed slot extending in from the periphery of the disc for approximately 1/3 of the diameter. Electrical connection is made to the disc by means of a flexible lead wire that extends longitudinally of the slot and is woven through apertures in the disc and held thereto at the terminal end by means of a spot-welded tab. Within the slot, an electrically insulative sleeve, such as silicone rubber, is placed over the wire. The wire with the sleeve mounted thereon is captured in the plane of the disc and within the slot by means of crimping tabs extending laterally of the slot and over the insulative wire.

Abstract: Disclosed is a coaxial antenna array for communicating circularly polarized electromagnetic radiation. A pair of open ended antenna cavities is coaxially constructed and operates by excitation of linear radiation elements arranged within each of the cavities. A pair of crossed-dipole radiation devices are centered within the inner cavity and operated by means of a phase-shifting network circuit to transmit as well as receive circularly polarized radiation. Four monopole radiation devices are symmetrically arranged to operate in the outer cavity in phase quadrature by means of the phase-shifting network circuit to also both transmit and receive circularly polarized electromagnetic radiation. Combined operation of the two antenna cavities with a 180.degree. phase differential between the fields related to the two antenna cavities provides a broad beam, relatively wide frequency bandwidth communication capability.

Abstract: A test structure for enabling the accurate measurement of the resistance characteristics of a semiconductor material, of the type which includes one or more pairs of electrical terminals disposed on the surface of the material to enable measurements of the resistance encountered by currents passed between the terminals. A pair of terminals includes a first terminal extending in a closed path, such as a circle, around a second terminal, so that all currents flowing between the terminals flows along a region of known width and length. Two or more pairs of concentric terminals can be utilized, wherein the ratio of radii of each pair of terminals is the same as the ratio for all other pairs of terminals, to facilitate the calculation of the contact resistance between each terminal and the semiconductor surface, as well as the calculation of the resistance of the semiconductor material apart from the effect of the terminal-to-semiconductor contact resistances.

Abstract: Disclosed is a multiple band antenna assembly for communicating electromagnetic radiation. An antenna element stack is constructed of a plurality of elliptical lamina antenna elements mutually separated by layers of dielectric material, and separated from a ground plane by dielectric material. The antenna assembly is coupled through a feed line in contact with the top antenna element. A conductor joins the remaining antenna elements to the ground plane. Each individual antenna element is operable for communication reception and transmission within a frequency band determined by the size of the particular antenna element. The antenna elements are arranged in order of decreasing size with the largest antenna element closest to the ground plane. The sizes of the antenna elements may be selected to provide electromagnetic radiation communication over several distinct frequency bands, or to connect the individual bands into a broad band.

Abstract: A method of growing a ribbon crystal wherein a meniscus of molten semiconductor material attached to vertical movable seed is lifted at a rate substantially equal to the rate at which the meniscus freezes, characterized by the steps of continuously sensing the brightness of the growth region of the ribbon in selected areas across the width thereof for detecting changes in the intensity of the brightness of said selected areas, and modifying the temperature of the meniscus and pulling speed in response to changes detected in the intensity for controlling the geometry of the ribbon.

Abstract: In combination with a susceptor particularly suited for use in growing a ribbon crystal employing edge-defined film-fed growth techniques and characterized by a susceptor including a die through which a melt is drawn for forming a crystal ribbon, a pair of jets for directing a stream of fluid coolant along a path extended to impinge on the susceptor in close proximity with the die in non-incident relation with the crystal being grown.

Abstract: A submultiple (30Fl) of an S-band transmitter output frequency (240Fl) is divided equally between a linear phase modulation branch and a QPSK modulation branch. The linear modulation branch includes a multiplier (X7) to increase the carrier frequency to a level (210Fl) which, when combined with the carrier in the QPSK branch in an up-converter (utilizing a mixer at the input thereof followed by a bandpass filter), produces the transmitter output frequency. This allows the QPSK modulator to operate at one-eighth of the output frequency where repeatable and precisely controlled modulation can be easily achieved. This also allows linear phase modulation at one-eighth the output frequency where low modulator deviation and good linearity can be easily maintained.

Abstract: A compact cryogenically coolable choked waveguide particularly for low-noise input coupling into a cryogenically cooled device, such as a maser or parametric amplifier, utilizes coaxial stainless steel support tubes surrounding the waveguide and connected in cascade to provide a folded low thermal conduction path. The edges of the tubes connected are welded.

Abstract: A system for determining the position of a vehicle or other target that emits radio waves, which is of the type that senses the difference in time of arrival at spaced ground stations of signals from the vehicle to locate the vehicle on a set of intersecting hyperbolas. A network of four ground stations detects the radio emissions from the vehicle, and by means of cross correlation derives the relative signal delay at the ground stations from which the vehicle position is deduced. Because the signal detection is by cross correlation, no knowledge of the emission is needed, which makes even unintentional radio noise emissions usable as a locator beacon. By positioning one of the four ground stations at an elevation significantly above the plane of the other three stations, a three dimensional fix on the vehicle is possible.

Abstract: Disclosed is an optical system for use in a multispectral scanner of the type used in video imaging devices. Electromagnetic radiation reflected by a rotating scan mirror is focused by a concave primary telescope mirror and collimated by a second concave mirror. The collimated beam is split by a dichroic filter which transmits radiant energy in the infrared spectrum and reflects visible and near infrared energy. The long wavelength beam is filtered and focused on an infrared detector positioned in a cryogenic environment. The short wavelength beam is dispersed by a pair of prisms, then projected on an array of detectors also mounted in a cryogenic environment and oriented at an angle relative to the optical path of the dispersed short wavelength beam.

Abstract: A system for generating within a single frame of photographic film a quadrified image including images of angularly, including orthogonally, related fields of view of a near field three dimensional object and characterized by a first subsystem including a plurality of reflective surfaces for imaging a first field of view of the object at one quadrant of the quadrifid image, a second subsystem including a plurality of reflecting surfaces for imaging a second field of view of the object at a second quadrant of the frame and a third subsystem including a plurality of reflecting surfaces for reflectively imaging a third field of view of the object at a third quadrant of the quadrifid image, all of which have identical path lengths to the object photographed.

Abstract: A heat treating fixture is disclosed in which the shape of the metal specimen is maintained by cold rolled steel support plates. Glide sheets of stainless steel, coated with boron nitride, in contact with each face of the metal specimens, allow for lateral expansion of the metal specimens without binding. Grooved support bars separate the glide sheets from the upper and lower support plates and allow flow of quenching fluid to the metal specimen.

Abstract: A dual acting control system for mass spectrometers which permits adjustment of the collimating slit width and centering of the collimating slit while using only one vacuum penetration. Coaxial shafts, each with independent vacuum bellows are used to independently move the entire collimating assembly or to adjust the slit dimension through a parallelogram linkage.

Abstract: Redundant operation of counter modules is maintained by detecting the zero state of each counter and clearing the other to that state, thus periodically resynchronizing the counters, and obtaining an output from both counters through AC coupled diode-OR gates. Redundant operation of counter flip-flops is maintained in a similar manner, and synchronous operation of redundant squarewave clock generators of the feedback type is effected by connecting together the feedback inputs of the squarewave generators through a coupling resistor, and obtaining an output from both generators through AC coupled diode-OR gates.

Abstract: In a micro-fluid exchange apparatus for exchanging fluid with an organ, such as the trachea or a blood vessel of a small animal, such as a rat or a mouse, a hollow needle, such as a syringe needle, is provided for penetrating the fluid conduit of the animal. The syringe needle is coupled to a plenum chamber having an inlet and outlet port. The plenum chamber is coupled to the syringe needle via the intermediary of a standard quick disconnect coupling fitting. The plenum chamber is carried at the end of a drive rod which is coupled to a micrometer drive head. The micrometer drive head is slidably and pivotably coupled to a pedestal for adjusting the height and angle of inclination of the needle relative to a reference base support. The needle is positioned adjacent to the incised trachea or a blood vessel of a small animal and the micrometer drive head is operated for penetrating the fluid conduit of the animal.

Abstract: Addition of a small amount, for example 1% by weight, of a liquid silicone oil to a metal containing solid rocket propellant provides a significant reduction in heat transfer to the inert nozzle walls eliminating metal oxide slag collection and blockage of the nozzle and increases burning rate by about 5 to 10% improving ballistic performance.