Abstract: Disclosed herein is a Pathlength Control Assembly for Ring Laser Gyroscope comprising, in a preferred embodiment, a mirror, coupled to a mirror housing including a mirror post, wherein the mirror is mounted on an axially deflectable membrane of the housing. A pair of piezoelectric transducers are responsive to an electronic input signal and mounted to a backing plate. The transducers are mounted within a driver housing and drive a driver post which is made from a thermally expansive material. As the backing plate is deformed to drive the mirror post to axially deflect the mirror membrane, the central driver post passively expands in response to temperature changes. In this manner, the transducers and thermally expansive mirror post act in conjunction to both actively and passively drive the mirror post over the full dynamic range of multioscillator or other ring laser gyroscope.

Abstract: Disclosed herein is a Pathlength Control Assembly for Ring Laser Gyroscope comprising, in a preferred embodiment, a mirror, coupled to a mirror housing including a mirror post, wherein the mirror is mounted on (or is an integral part of) an axially deflectable membrane of the housing. A pair of piezoelectric transducers are responsive to an electronic input signal and mounted to a backing plate. The transducers sandwich the backing plate and deform the backing plate to drive the mirror post to axially deflect said membrane. In this manner, the backing plate serves a dual function to both support the piezoelectric elements and drive the mirror post.

Abstract: A ring laser gyroscope output optics detection system, including a rotational sensing system and cavity length control system for a multioscillator ring laser gyroscope, is disclosed herein that can operate with a simple upright symmetric optics mechanism, where the required signal separation is performed fully electronically. In a preferred embodiment, signal separation circuitry is provided which performs a 90.degree. or .pi./2 radians phase shift to one of a set of heterodyned signals in order to extract the sagnac effect modulated Faraday frequency signals W.sub.A and W.sub.B. In order to deal with the inherent problems of crosstalk present in a Faraday biased system, alternative signal separation schemes suggest the use of a 45.degree. or .pi./4 radians phase shift, as well as a 60.degree. or .pi./3 radians phase shift. Complementary cavity length control schemes are presented in both fixed component and digitally controlled formats.

Abstract: Disclosed herein is a Ring Laser Gyroscope Mount comprising a low coefficient of expansion metal Invar sleeve and mount coupler. The sleeve may be secured to the gyroscope pedestal by being screwed and affixed to a relatively high coefficient of thermal expansion material pedestal, such as HyMu 80. The sleeve is attached also to the glass frame by cementing it at selected locations within the central mounting aperture of the gyroscope frame. This securement procedure makes the assembly stiffer in directions perpendicular to the axis of the coupler. At least one concentric groove which surrounds the coupler is machined into at least one side of the frame to reduce stress at gyroscope mirror surfaces during thermal excursions. The clearance gap where the cement is placed, the groove depth and shape, and the sleeve and coupler are designed to be stiff but not induce distortion.

Abstract: Disclosed herein in a side mounted aperture and a Faraday rotator assembly useful in conjunction with an out-of-plane multi-oscillator ring laser gyroscope. The aperture and Faraday rotator assemblies contain components which are optically contacted to one another as well as the ring laser gyroscope frame. The assemblies disclosed herein provide a simplified construction designed to fixture the Faraday rotator element in order to minimize handling and facilitate alignment to the ring laser gyroscope cavity, free from contamination and in proper alignment for optimum use of the Faraday rotator component and aperture needed for proper operation of an out-of-plane multi-oscillator ring laser gyroscope.

Abstract: A method and system of ring laser gyroscope mirror orientation is disclosed which provides minimal backscatter within the closed optical pathway as a result of analysis and manipulation of the speckle pattern associated with each of the mirrors defining the optical pathway.

Abstract: An electronically tuned dielectric resonator stabilized oscillator has a dielectric resonator that is fine tuned by an electronic method of tuning which includes a varactor coupled to a microstrip. This varactor microstrip transmission line is positioned below the dielectric resonator but above the plane in which a transmission line for the carrier frequency resides. By not placing the fine tuning microstrip line on the same plane as the main oscillator line, spurious oscillation between the fine tuning transmission line and the primary carrier wave resonator frequency line are minimized. Additionally, the fine tuning microstrip line is positioned orthogonal to the pathways along which the main signal transmission lines are coupled.

Abstract: In certain composite plastic pipe manufacturing operations it is necessary to provide an adhesive coating between the core pipe and the fiber glass reinforced layer, especially if the core pipe is a thermoplastic and the fiber glass reinforced material is a thermoset resin. In the disclosed coating apparatus (2), a coating chamber (4) is provided with seal means (20) at a first wall (14) and seal means (22) and a second wall (16), preferably a second chamber (40) is provided with a similar seal means (44). The coating chamber is maintained in a filled condition with a liquid coating material via a circulating pump (48) and associated reservoirs (34, 36, etc.). Rollers (62, 64) maintain the pipe sections in correct positional relationship with the coating apparatus.

Abstract: Certain pipe sections require an annular sealing gasket to be permanently positioned on the spigot portion. This is especially desirable with pipe sections formed with helically preceding reinforcing ribs. Disclosed is pipe section including a spigot end 2 having an annular groove 4 positioned adjacent the end surface thereof. Within groove 4 is placed fluid, settable bedding material 14 which has positioned therein and impregnated thereby a reinforcing material 15, preferably consisting of a ribbon of fiberglass material. Annular sealing gasket 3 is positioned in this groove 4 and onto the settable material 14 which is caused to intimately contact both the surface of the groove 4 and the sealing gasket 3. The thus sealed, bonded and reinforced spigot end retains the structural integrity and resistance to crushing loads and impact strength as is inherent in the rib reinforced pipe section.

Abstract: A breakaway valve fitting includes a housing which defines a passage therein and a breakaway assembly connecting the housing to a conduit. The breakaway valve fitting further includes a poppet valve element mounted for axial movement within the housing between open and closed positions, the poppet valve element defining a first axial fluid flow path about the perimeter thereof when in the open position. A first valve seat is defined in the housing passage and cooperates with the poppet valve element when in its closed position to obstruct the first fluid flow path. The breakaway valve fitting further includes a rotatable valve element mounted for axial and rotational movement within the housing between open and closed positions. The rotatable valve element includes a central bore which defines in conjunction with the poppet valve element a second axial fluid flow path when the rotatable valve element is in its open position.