Abstract: The present invention is directed to an improved combination hay trailer and tiltable bed and a method related thereto for loading and unloading round bales, the improvement comprising a rotary hinge assembly positioned along the combination and adapted for angular rotation of the bed about the trailer, the hinge assembly including an outer hinge structure spaced from an inner hinge structure, the inner hinge structure associated with one of the bed and trailer, the outer hinge structure being associated with the remaining bed or trailer, and a hinge sleeve extending through said hinge assembly, wherein said tiltable bed is biased downwardly.

Abstract: A control arrangement for minimizing optical leakage in a time-division, multi-stage electro-optical switch by the periodic adjustment of switching voltage levels. An optical detector connected to an idle port of the switch transmits a leakage signal which represents optical leakage in the switch in various configurations of the switch. The leakage signal is filtered by a low pass filter and sampled at a low rate. A processor stores the sampled data and periodically analyzes the data to determine the appropriate changes in the switching voltage levels for each of the stages of the switch to minimize optical leakage. An output circuit connected to the processor and the switch modifies a previously determined base voltage signals for each of the stages to incorporate the voltage level changes and applies the modified signals to the switch in the appropriate time slots.

Abstract: A rectification error reducer for a fiber optic gyroscope, which is an intensity servo or compensator for reducing vibration effects in the optical signals caused by modulation at vibration frequencies induced by the gyroscope operating environment. The vibration effects may be detected in signals from the photodiode output in amplitude form which is used in a control system to null out optical intensity variations at the frequencies of vibration.

Abstract: A rectification error reducer for a fiber optic gyroscope, which is an intensity servo or compensator for reducing vibration effects in the optical signals caused by modulation at vibration frequencies induced by the gyroscope operating environment. The vibration effects may be detected in signals from the photodiode output in amplitude form which is used in a control system to null out optical intensity variations at the frequencies of vibration.

Abstract: A fiber optic sensor coil is wound from a length of optical fiber with the mid-point of the optical fiber at the mid-point of the innermost layer of the coil and subsequent layers of the coil each have alternating turns of the two sections of the fiber emanating from the mid-point. The layers of alternating turns are formed by first winding a portion of one segment in such a fashion that adjacent turns are spaced apart by a distance equivalent to the diameter of the optical fiber. The layer is completed by winding a portion of the other segment such that the turns of the other segment are disposed between adjacent turns of the one segment. The number of turns in adjacent layers are unequal such that the turns of a next layer are arranged in grooves formed between two adjacent turns of optical fiber in the previous layer.

Abstract: A fiber optic sensor coil is wound from a length of optical fiber with the mid-point of the optical fiber at the mid-point of the innermost layer of the coil and subsequent layers of the coil each have alternating turns of the two sections of the fiber emanating from the mid-point. The layers of alternating turns are formed by first winding a portion of one segment in such a fashion that adjacent turns are spaced apart by a distance equivalent to the diameter of the optical fiber. The layer is completed by winding a portion of the other segment such that the turns of the other segment are disposed between adjacent turns of the one segment. The number of turns in adjacent layers are unequal such that the turns of a next layer are arranged in grooves formed between two adjacent turns of optical fiber in the previous layer.

Abstract: A force detecting microsensor comprises a single crystal Si substrate, a single crystal cone formed on the substrate and a resilient electrode mounted above the tip of the Si cone. The space between the tip of the Si cone and the resilient electrode is maintained in a vacuum environment and the distance between the tip and the resilient anode is in the order of a few atomic diameters. The tunneling effect of electrons occurs between the tip of the Si cone and the resilient electrode when a potential is applied to the resilient electrode and the Si cone tip. The resilient electrode deflects as a result of the force acting on the microsensor. The deflection of the resilient electrode alters the electrical characteristics between the resilient electrode and the Si cone tip. The changes in the electrical characteristics can be measured to determine the level of force acting on the microsensor.

Abstract: A force detecting microsensor comprises a single crystal Si substrate, a single crystal cone formed on the substrate and a resilient electrode mounted above the tip of the Si cone. The space between the tip of the Si cone and the resilient electrode is maintained in a vacuum environment and the distance between the tip and the resilient anode is in the order of a few atomic diameters. The tunneling effect of electrons occurs between the tip of the Si cone and the resilient electrode when a potential is applied to the resilient electrode and the Si cone tip. The resilient electrode deflects as a result of the force acting on the microsensor. The deflection of the resilient electrode alters the electrical characteristics between the resilient electrode and the Si cone tip. The changes in the electrical characteristics can be measured to determine the level of force acting on the microsensor.

Abstract: An optical rotation sensor comprises a light amplification stimulated emission ring laser formed in a solid medium is provided with phase modulator devices which produce push-pull phase modulation of counterpropagating optical waves in the ring thereby enhancing bidirectional lasing in single longitudinal modes in each direction. A frequency selective output coupler couples a predetermined portion of the optical energy at the lasing frequency from the ring to an output waveguide. A substantially U-shaped output waveguide having legs extending away from the ring in opposite directions and toward a common position. Clockwise and counterclockwise light waves are coupled from the ring to the two separate legs of the output waveguide and are directed to the common position to create an interfering light pattern on photodetector apparatus. The interfering light pattern is indicative of the rate of rotation, as defined by the Sagnac effect.

Abstract: An optical rate sensor apparatus (300) measures rates of angular rotation along a plurality of orthogonal axes. The apparatus (300) comprises a passive ring Sagnac interferometric arrangement having a light source circuit (308) and a series of multi-turn fiber optic rings (302, 304, 306). An optics/modulator circuit (312) selectively switches optical waves emitted from the light source circuit (308) into gyroscope channels and transmits the signals through fiber optic rings as counter-propagating optical waves. The optics/modulator circuit (312) also recombines the optical waves after they emerge from the corresponding rings. The optics/modulator circuit (312) includes optical components integrated onto an integrated optics chip (IOC) consisting substantially of lithium niobate. Optical fibers (606, 608) are coupled from the rings (302, 304, 306) to the integrated optics chip.

Abstract: A triad sensor apparatus (300) comprises a passive ring Sagnac interferometric arrangement having a light source circuit (308) and a series of three multi-turn fiber optic rings (302, 304, 306). An optics/modulator circuit (312) is adapted to selectively switch optical waves emitted from the light source circuit (308) and transmit the signals through the corresponding fiber optic rings as counterpropagating optical waves. Nonreciprocal phase modulation is applied to the counter-propagating waves, and the waves are recombined so as to produce a "zero order" fringe pattern having an intensity varying in accordance with the relative phase between the counterpropagating waves. Optical waves from the light source circuit (308) are selectively applied to a ring path during a given time period, while the photodetector circuit (324) is detecting light waves which have emerged from another ring path during the same given time period.

Abstract: An optical rate sensor (200) is disclosed for use in inertial reference systems to measure rates of angular rotation with substantially high resolution and sensitivity. The sensor (200) comprises a passive ring Sagnac interferometer (201) with a multiturn fiber optic ring (232) through which counter-propagating optical waves are transmitted. A nonreciprocal time variant phase modulation is applied to the waves along with periodic effective transposition of ring ports. The waves are combined to produce a "zero order" fringe pattern having an intensity varying in accordance with the relative phase between the counter-propagating waves. An intensity signal is derived from the fringe pattern having a phase offset corresponding to the Sagnac induced phase shift which in turn is linearly proportional to the angular rotation rate of the passive ring. Sampling, averaging and estimation circuits detemine the offset by detecting zero-crossing locations of the signal.