Abstract: An elastic surface wave accelerometer having a deformable structure, fixed at one end and providing at its free end a seismic mass. The deformable structure may be an open frame with a single post or a closed frame with two posts. The accelerometer can measure movement of a missile or that of a gravitational field.

Abstract: A buoy has accelerometers and magnetometers for measuring characteristics of an ocean swell. The main plane of the buoy floats on and follows the motion of the free surface of the ocean water. A first accelerometer and a magnetometer are mounted on the buoy and oriented along the axis which is perpendicular to the main plane of the buoy (i.e. perpendicular to the surface of the ocean swell). A pair of accelerometers and magnetometers are mounted in the main plane of the buoy and are oriented along mutually perpendicular axes of that plane. The swell caused acceleration vector is perpendicular to the main plane (i.e. the free surface of the water). The accelerometer oriented perpendicular to the main plane measures the sum of the swell caused acceleration vector and the projection of the gravity vector along the axis of the buoy. The mutually perpendicular pair of accelerometers mounted in the main plane measure the projection of the gravity vector in the main plane of the buoy.

Abstract: Asymmetries of rotatable members such as aircraft propellers can be balanced out by the careful addition of counterweights at proper positions on the members. An accelerometer coupled to the mounting of an unbalanced rotating member produces a signal containing a component indicative of the unbalance. This signal would be useful for helping in the balancing process but it may also contain noise components from which the useful component has to be extracted without too much alteration. A fixed frequency band-pass filter could be used but the results then have to be manually corrected if the actual frequency varies from that associated with the filter or a manually turnable filter could be used but then of course the filter has to be tuned for each test.

Abstract: Method and apparatus for determining the vertical gradient of the vertical gravitational field by a single measurement, for example, adjacent an earth formation of interest, are provided.

Abstract: An apparatus for inertially determining the rate of angular rotation and translational motion of a structure is provided which utilizes a pair of vibrating accelerometers vibrating along a single axis with their force sensing axis located normal to the axis of vibration and rotated 90.degree. from each other. Signals from the vibrating accelerometers can be processed to provide indications of angular rotation about two axes and translation motion about two axes. Two of the sets of vibrating accelerometers can be combined to provide a three axis inertial reference system.

Abstract: An accelerometer including a flexible pivot, a base to which one end of the flexible pivot is fixed, a pendulum fixed to the other end of the flexible pivot, a pair of torquers generating a torque in proportion to the acceleration applied through the base to the pendulum, and a displacement detecting device for electrically detecting a relative displacement of the pendulum to the base is disclosed, in which the above-mentioned base consists of first and second frames. The first frame is provided with a fixing part to which one end of the flexible pivot is fixed, a fixing portion to which the displacement detecting device is fixed, and an engaging portion to be engaged with an engaging portion provided on the second frame, whereby the assembly of the accelerometer can be made simplified and easy. The accelerometer of this invention is simple in construction and maintains its characteristics unchanged for a long period of time.

Abstract: An apparatus is provided for the continuous measurement of the bulk density of particulate material comprising an endless belt weighing conveyor having a compression zone and a weigh span downstream of the compression zone, means for feeding the material to said compression zone, a compression unit at said compression zone having a series of rollers an axes extending transverse to the direction of movement of the weighing conveyor, and transducer means provided at the weigh span for producing signals proportional to material weight. The rollers may be driven with a surface speed equal to the weighing conveyor belt speed and additional rollers may be mounted below the weighing conveyor to carry the load. The rollers are preferably embraced by a belt which gives a continuous surface and prevents tobacco getting between the rollers. In which case, the belt is driven with the same speed as the weighing conveyor belt, via a terminal roller and the other rollers follow.

Abstract: In an inertial system for sensing the angular rotation and translational motion of a structure utilizing a pair of accelerometers in a back-to-back arrangement vibrating substantially linearly along an axis normal to their force sensing axes, a mechanism utilizing a parallelogram structure is used to impart the vibratory motion to the accelerometers.

Abstract: A first processing circuit receives signals from a vibratory acceleration and a speed of rotation and position sensor and comprises integration and filter means for providing a signal (sb) representative of the amplitude of any untrue running. A second processing circuit receives the output signal (sw) from the speed of rotation and position sensor and the signal (sb) and includes means for determining the phase difference between the signals (sw) and (sb). A memory (33) stores information representative, for different revolving systems and/or test conditions, of the difference between the measured phase difference and the angular position of an imbalance causing untrue running with reference to an origin on the revolving system. Appropriate information is read from the memory and combined with the measured phase difference in response to the actuation of selection means to provide an accurate output of the angular position of any imbalance causing untrue running.

Abstract: A device for indexing a rotor (17) of a machine (13) to be balanced utilizes the output signal (A) from a generator (15) connected to the machine rotor (17). The generator (15) produces a continuous sinusoidal output signal (A) proportional to the position and speed of the associated rotor (17). Detector means (37) detect a predetermined output from the generator (15) so that an indicator (41) issues an indication each time the detector means (37) detects the predetermined output. Thus, an operator can physically index the angular position of the rotor (17) with respect to the predetermined output (A) from the generator (15) when an indication is provided so that the position of the rotor (17) is referenced to the output signal (A) of the generator (15).

Abstract: A system for dynamically balancing a wheel utilizes low speed (preferably 50 to 100 rmp) rotation of the wheel that can if desired be provided manually. In manual operation as the rotation is imparted to the wheel by an operator, the rotational speed of the wheel is measured, and an indicator notifies the operator when sufficient rotational speed has been imparted to the wheel to enable a balancing operation to be carried out. Thereafter the wheel is allowed to coast and decelerate until the sensed forces have adequately settled out, then the forces of imbalance transmitted by the rotatable shaft are measured. When the measurements are obtained, any detected imbalance of the wheel is displayed on a suitable indicator mechanism.

Abstract: The present invention employs a mass which is movable toward or away from a detection device. The detection device generates electrical signals which because of their polarities and amplitudes act, when transmitted to an electrical coil, to provide torque and move the mass to an equilibrium position. The electrical signals also serve as a measure of forces on, or an indication of a position of, the device with which the present detector is used. The mass and the coil are mounted on shaft means which in turn is mounted in a pair of ball bearing assemblies. The ball bearing assemblies fit around the periphery of the shaft to provide substantial lateral restraint and further fit at the ends of the shaft to provide substantial vertical restraint. In addition the present invention provides a pair of heavy flux density producing magnets, which are separated by a gap within which the coil moves.

Abstract: A shielded, closely spaced transmit-receiver system for use in an electronic article surveillance system is disclosed wherein at least one of the antennas is provided with at least two twisted loops lying in a common plane each loop being twisted 180.degree. to be in phase opposition with the adjacent loop and wherein both antennas are substantially enclosed by a conductive shield having a discontinuity in an outer portion enclosing each of the twisted loops.

Abstract: A simple and rugged alarm which is versatile in application includes a battery connected through first and second parallel switches to a light and buzzer alarm. The first switch comprises a first contact formed in a conductive plate and yieldably biased to an open position and a lever actuated cam for rotatably engaging and moving the first contact to a closed position. The second switch includes a second contact formed in the conductive plate which is yieldably biased to a closed position and a retractable pin for supporting the second contact in an open position.

Abstract: In the plating of wire, particularly gold plating of wire for terminal pins, obtaining a high quality fixed gold plate is a problem. The invention provides for testing the wire prior to plating to detect surface irregularities which affect the quality of the plate. A test length of wire has a length of tape wrapped spirally around, with at least an edge portion in contact with the wire. The wire, and tape, is then twisted, in the direction of the spiral of the tape, in a direction to tighten the tape. The tape is then unwound and the number of particles of wire material which have separated from the wire at defects adhere to the tape is counted. For premium grade wire, less than 6 defects per foot is a standard. Commercial grade wire, between 50 and 150 defects per foot is normal.

Abstract: A dynamic electric wheel balancer for measuring the imbalance condition in a vehicle wheel and indicating the position and correction weights required for balancing the wheel in one or two planes. The wheel balancer contains a rotating shaft in order to make the dynamic measurements. The shaft is freewheeling during measurement and is brought up to a predetermined minimum r.p.m. value through a motor and clutch arrangement. In order to take the measurements, piezoelectric sensors are used to measure the vertical force components exhibited by the imbalance condition of the vehicle wheel secured to the rotating main shaft. The measured force components are converted into digital form. The balancer finds the definite integral of each of the forces generated by the piezoelectric transducers and uses the cross correlation data generated by these integrations to find the zero crossing points and the peak determinations.

Abstract: This invention is directed to a system for detecting the presence of moisture in a given location such as the attic of a building or house before the moisture has had an opportunity to penetrate plaster walls or cause other damage. The disclosed invention includes a detector for detecting the presence of minute quantities of moisture contemporaneous with their initial appearance, which responds to the presence of moisture by exhibiting a decrease in its internal impedance. An audible signal-generating circuit is coupled to the detector and responds to the resultant decrease in the impedance of the detector by commencing to oscillate at a pre-determined audio frequency.

Abstract: A method for detecting knocking in internal combustion engine, wherein a plurality of constants K is stored corresponding to a plurality of ranges of engine speed. A reference value is calculated from a means value of an output signal of a knock sensor, from the constant K corresponding to an engine speed and from a predetermined offset value, through a calculation of multiplying the mean value by the constant K and adding the offset value to the result of the multiplication. Then an output signal, newly provided from the knock sensor after the calculation of the mean value, is compared with the reference value so as to decide that knocking occurs in the engine when the newly given output signal of the knock sensor exceeds the reference value. Therefore, the reference value can be suitably determined corresponding to the engine speed so that a detectable lower limit of knocking intensity is kept to be substantially constant.

Abstract: A fluid filter monitoring system includes a filter relief valve movable in response to a pressure buildup caused by filter clogging to sequentially actuate a pair of pressure-operated switches. A temperature sensor senses the temperature of fluid in the hydraulic system. A control unit, including a microprocessor, controls the energization of a plurality of indicators, depending upon the status of the temperature sensor, the pressure-operated switches and the duration of actuation of the switches.

Abstract: An apparatus for determining the imbalance in a rotating object has a drive means for rotating the object about an axis. Transducers measure the force of imbalance of the rotating object, with each transducer producing an electrical signal in response thereto. Electronic means receives the signals from the transducers and calculates the imbalance in the object. Drive means is directly coupled to the rotating object, such as a tire, with the drive means in the hub of the wheel on which the tire is mounted. Cantilever support means having a substantially planar surface provides support for the drive means onto the transducers in the frame of the apparatus.