Abstract: A ring laser wherein, in the preferred embodiment, the laser path is substantially square, and the path length is adjustable by making at least one of the mirrors slightly tilted and one of the mirrors concave with at least the concave mirror translatable.

Abstract: A piezoelectric transducer drive for use within a ring laser gyro is shown wherein a resistive element is combined in a negative feedback loop with a second resistive element to provide a feedback signal which is constant with variations in the transducer material and linear with temperature change. The feedback signal is amplified and applied to a comparator whose output is modulated with an AC signal and applied to a power amplifier that drives the piezoelectric transducer for controlling the displacement thereof uniformly over a wide temperature range.

Abstract: An improved laser gyro dither mechanism is shown utilizing a three-spring suspension system which isolates dither vibrational energy generated within the gyro and prevents that energy from passing to the mounting case of the laser.

Abstract: A torque converter for inclusion between a driving shaft and a driven shaft. Preferably there is more than one torque generator and a gear train in parallel between the input and output shafts. The torque generators and any attached driving gears rotate about shafts whose axes are preferably symmetrically displaced about, and are stationary relative to, the axis of the input shaft. The above mentioned torque generators each preferably have a pair of radially opposed eccentrically mounted weights thereon. Preferably there are at least two pairs of weights on each torque generating train, together with means for varying the phasing between the pairs of weights. Means is also provided for accommodating slight misalignments between the shafts of the torque generating trains. Each of the torque generating trains has attached thereto at least one unidirectional clutch which allows the shafts to turn in only one direction.

Abstract: An apparatus for changing an analog input voltage into a pulse rate particularly characterized by (1) the absence of substantial voltage across switching mechanisms, (2) the generation of pulses having precise charge content, and (3) the production of positive and negative pulses having precisely the same charge content.

Abstract: A single mode laser gyro having two oppositely traveling laser beams is provided with mechanically dithered mirrors at its three or four reflection points. Each mirror is mounted for movement in and out as the result of the expansion and contraction of stacks of piezoelectric elements associated with each mirror. The mirrors are dithered or oscillated in and out, at the same frequency and in phase relationship with one another so that the perimeter distance for the laser cavity is held at a fixed number of wavelengths, but the laser beam translates back and forth across the faces of the mirrors. By this technique, the undesired phenomena of lock-in at low rotation rates is avoided, without the need for special optical or magnetic structures in the path of the laser beam.

Abstract: A method for making a glass-or ceramic-to-metal seal, and the seal itself. A layer of gold is deposited onto the metal. A thin layer of indium is placed over the gold, and the structure is heated above the melting point of indium to create a gold-indium alloy at the gold-indium interface. After cooling, the indium surface of the structure and the glass surface are super-cleaned. The super-cleaned surface are then pressed together to form an air-tight seal.

Abstract: A DC-to-DC Converter using four tightly coupled transformer windings, two energy transfer capacitors, and a pair of switching devices connected to remove the ripple from both the input and output current circuits. The switching devices are driven in response to a switching signal.

Abstract: Apparatus for containing a ferro-fluid within a reservoir of ferro-fluid using a pair of ferro-magnetic members adjacent each other and having opposing surfaces shaped as segments of surfaces of revolution, including magnetic apparatus for producing magnetic flux across the gap between the opposing surfaces. The surfaces diverge, and the greater magnetic flux density at the closely spaced edges of the pocket formed by the surfaces hold the ferro-magnetic particles of the ferro-fluid in that region. The volume between the two opposing surfaces is adequate to accommodate the thermal and pressure expansion and contraction of the fluid. The spacing between opposing members at the edge of farthest advance of the fluid is sufficiently small to allow the surface tension of the fluid to hold the fluid.

Abstract: A nonplanar ring laser for use as a laser gyro includes an even number of at least six reflecting surfaces which are preferably all made from the same coating batch or coating run so that they have substantially the same anisotropy characteristics. The mirrors are divided into pairs of mirrors, and the mirrors in at least each pair must match in their anisotropic characteristics. Note that the matched mirrors need only be in the laser path but not necessarily adjacent.The nonplanar geometric arrangement of the reflecting surfaces is such that the reflecting plane of incidence of each mirror is at substantially a right angle to the reflecting plane of incidence of at least one of the adjacent mirrors in the laser path. Note that the reflecting plane of incidence of each mirror may optionally be at right angles to the reflecting planes of incidence of both its adjacent mirrors in the laser path.The angles of incidence of the mirrors in each matched pair must be substantially the same.

Abstract: Apparatus for chopping DC power at a high frequency, for example 20 kHz, such high frequency being pulse-width modulated by a lower power frequency source at the desired power frequency. The pulse width modulation is servo controlled through current and voltage feedback to cause the current delivered to a load impedance to be in phase with a reference to power frequency oscillator and to control the output frequency voltage amplitude.

Abstract: A belted-track vehicle, unpowered and attached to a cantilevered apparatus to support the apparatus clear of the ground and adapted to be driven by the apparatus.

Abstract: An apparatus for positioning the target marker in a toss-bombing display to allow toss-bombing when the wings of the bombing aircraft are not level.

Abstract: A ring laser gyroscope system is provided in which four frequencies of oscillation are allowed to simultaneously propagate within the ring laser cavity, with two modes propagating in each direction. Separation of the resonant frequencies is accomplished through reciprocal, nonreciprocal, and anisotropic optical effects within the laser path, plus Zeeman effect produced by a magnetic field in a predetermined intensity range over the laser gain plasma. The magnetic field substantially parallel to the laser path over the gain medium reduces the effects of hole burning or source depletion when the amplitudes of the field is within a predetermined intensity range to allow frequencies of the four modes to be spaced closer together. The system employs cavity length control circuitry to optimize system output. Rotation of the system results in frequency changes which are detected and processed to yield inertial rotation information.

Abstract: A flexure hinge assembly comprising a pair of fixed telescopes inner and outer tubular members separated into at least one driving portion, at least one gimbal portion and at least one driven portion and a plurality of flexure blades all formed by a plurality of slots and apertures through the walls of each tubular member. Flexure blades are formed by pairs of adjacent apertures with the slots interconnecting apertures to separate the tubular members into the driving, gimbal, and driven portions. The four slots of each tubular member which divide that member into these three portions are axially coextensive with the slots in the other member and all extend in the same axial direction from the apertures which form the flexure blades. Such axially coextensive slots displace the driving and the driven portions of the tubular members in the same axial direction from the center of suspension, i.e., from the flexure axes of these portions.