Abstract: A gear defect analyzing system records the interaction of each tooth of a gear system until the interaction begins to repeat and then processes the information in such a way as to identify defective gear tooth. Signals from a gear box are detected by an accelerometer and a shaft encoder and fed to an interface circuit and then to an analog signal preprocessing circuit. The preprocessing circuit conditions the signal so that it can be analyzed by a microcomputer. The system has the capability of identifying the class of incoming signals, determining the optimal time domain average, eliminating unwanted spectral components and interference, computing specific measurements relating to gear wear and then performing analysis of time history within a given system operating state to determine which gears and gear teeth are defective. By recording each tooth-to-tooth interaction over a period of time, and then processing the recorded matrix of data, it is possible to locate individual tooth defects.

Abstract: A system and method for monitoring machine tool operations provides a multi-level tool break alarm and uses information from multiple sensors of different types. Signal processing and pattern recognition logic techniques are applied to a cutting process high frequency vibration signal to detect major tool breaks requiring prompt stoppage of the cut. False alarm resistant detection of minor tool breaks, for which the response may not be an immediate stop of the cutting process, is obtained with information from a low frequency vibration sensor, an axis drive current sensor, or an axis velocity sensor. A minor tool break alarm is generated when signal transients in both a high frequency and low frequency channel signal are in close time coincidence, and a major alarm when the high frequency channel transient is followed by a persisting mean vibration level shift.

Abstract: Disclosed are two arrangements for remotely indicating the status of a washing machine and/or a dryer. In one arrangement, a current sense circuit is employed along with an optional vibration sense circuit to detect whether or not the washing machine or the dryer are on or off. At a change from on-to-off or from off-to-on, the status of the washing machine or dryer is transmitted over the air to a receiver for status display to the operator. In the second arrangement, detection of the status is internal to the washing machine and the dryer and the status includes additional information such as the type of cycle and the amount of time left before the cycle finishes. To avoid constant transmission of such information, the receiver includes a timer which is synchronized to the washing machine/dryer timing circuits.

Abstract: A detector for an alarm system receives a disturbance signal and transmits an alarm signal to a remote station. A group of such detectors can be connected in circuit to operate a common alarm. The detector has means (6, 26, 33) for suppressing a first disturbance signal so that only a second and subsequent ones trigger the alarm. There are also means (8, 30) whereby a disturbance signal only of a given length can pass to trigger the alarm. With another facility (38, 43) the detector registers whether it is the first or a subsequent one in a group to be disturbed. The detector is largely embodied on a integrated circuit chip and all these facilities are selectable by making or omitting simple pin connections.

Abstract: A device for detecting the unbalance of a rotating machine from a predetermined threshold. This device includes a pendulum formed from a vertical rod made of an elastically deformable metal, the upper end of which is embedded in an insulating support fixed rigidly to the housing of the rotating machine and which at its lower end carries a metallic mass, the mass being received concentrically, with a predetermined peripheral play, within a metal rink likewise fixed to the housing and insulated electrically from the housing, the ring and the embedded end of the pendulum being connected electrically to an electrical alarm or safety circuit which closes as soon as the mass comes in contact with the ring, where the resonance frequency of the pendulum is below that of the parts of the rotating machine which is subjected to the unbalanced condition.

Abstract: Gradual wear or breakage of a machine tool which occurs over a period of time is detected by sensing high frequency vibrations produced at the cutting tool/workpiece interface during a machining process. The high frequency vibrations are converted to a unipolar vibration signal which is processed to produce a tracking signal which tracks the minimum value of the vibration signal. The vibration signal is related to the effective cutting energy and it decreases due to gradual tool wear or breakage. The tracking minimum signal is compared to a predetermined threshold level to detect excessive wear or breakage of the tool, and an alarm is provided.

Abstract: A novel system for determining the magnitudes of loads on rotating helicopter components from signals remotely measured on the helicopter fuselage is characterized by a processor which decomposes the measured signals into corresponding Fourier components and extracts selected components therefrom. A programming module performs a multiplication on the respective Fourier components to correlate the measured components with corresponding determinative parameter values. The parameter values are established in a calibration process which is characterized by determination of the independent values of a measured signal set using a Jones orthogonalization process. The signals output from the coefficient programming module are provided to a multiplying resolver which receives synthesized reference sinusoids from a digital processor and generates time dependent signal components therefrom. These signals are ultimately summed in an analog summer circuit whose output signal corresponds to the desired parameter signal.

Abstract: An arrangement for automatic release of occupant protecting devices in vehicles, particularly power vehicles, by means of producing a control signal in response to a deviation from an acceptable position or an acceptable condition of a vehicle, the arrangement comprises a sensor including a base plate provided with at least one coil through which a high-frequency alternating current flows, a seismic mass composed of an electrically conductive material at least in the region of the coil and movably suspended near the base plate so as to be in an operative connection with the coil, a pendulum-like suspending member which supports the seismic mass so as to enable a substantially parallel movement of the seismic mass relative to the coil, and a perforated member which coats the coil, the perforated member being composed of an electrically conductive material and provided with at least one slot.

Abstract: Vibrations at the groove cutting tool-workpiece interface are sensed by a vibration sensor such as, for example, an accelerometer, and the vibration sensor output is processed to yield an electrical signal indicative of groove cutting tool cutting noise vibration. Digital analysis of the electrical signal after it is sampled is performed to detect various types of groove cutting tool break event signatures, and especially a type of signature in which a high amplitude positive going spike is followed by a significant shift in the mean amplitude signal level of the background cutting vibration. A machine tool monitor, system and method are disclsoed which detects such changes and interprets them to detect groove tool break events of sufficient magnitude to endanger the machined part.

Abstract: Substantial cutting condition changes which occur in intermittent bursts as rough surfaced workpieces are turned generate specific vibration signal signatures known as the runout condition. Either an upper or a lower threshold is set and all mean signal samples are compared with the threshold value. When the mean cutting noise exceeds the upper threshold or stays below the lower threshold for a preset number of signal samples, a tool break alarm is generated. Techniques are given to reduce false alarms on runout during initial rough surface cuts. The system comprises an accelerometer or other sensor whose signal is processed to attenuate lower frequency machinery noise and to detect the signal energy in a band below 100 kHz, then sampled, and the digitized signal samples analyzed by pattern recognition logic.

Abstract: A user-programmable sensor system for generating an alarm signal upon detection of an alarm event is disclosed. The system is particularly suited for use in vehicle security systems. The system employs a three axes accelerometer as a shock/motion detector, and the transducer outputs are summed and the composite signal filtered to provide several channels, each covering a specific frequency or frequency band. The outputs of the channels are digitized and processed by a microprocessor. An event is characterized by seveal signal parameters with an alarm event triggered by the simultaneous occurrence of several predetermined conditions, and not just one condition. The limit values for the signal parameters which are required to qualify a shock/motion event as an alarm event may be readily programmed by the user at any time or place.

Abstract: A method of digital automatic gain control does the required circulation without numerical multiplication or division and makes possible fast process control using a digital AGC. A signal channel has a digitally programmable variable gain device such as a multiplying digital-to-analog converter; the gain control input of the variable gain device is adjusted periodically to keep the exponential average of the digitized channel output signal with a given time constant at a desired average signal level. For instance, the vibration signal generated by a cutting process is held at a desired average prior to vibration pattern analysis to detect tool breakage and tool touch to a workpiece.

Abstract: A tool break detection system has an automatic gain control to adjust the analog signal channel gain and hold the cutting vibration signal at a desired average level. The AGC time constant is long enough that the detection of abrupt tool breaks and sudden large signal level transistions by the digital signature recognition logic is unaffected. However, the gradual decrease in signal level produced by a crumbly-type break would be removed by AGC action. In a system with a hardware AGC, crossing a high gain threshold resets gain to a low value and the resulting abrupt and persisting change in signal level is detected by the abrupt tool break logic. Another embodiment uses the gain command output by a software AGC and generates a break detected signal directly, without resetting the gain command, as gain rises above a high gain alarm level which is recalculated at the start of each cut.

Abstract: The initial contact of a rotating milling tool to a workpiece is detected in the presence of spurious noise spikes by digitally processing samples of a preprocessed vibration signal concurrently through basic tool touch detection logic and milling tool touch detection enhancement logic, and generating a touch indication if either logic set is satisfied. The basic logic detects a continuously increasing signal level higher than a threshold set above background noise. The milling logic detects an above-threshold signal sample and sets up an acceptance window about the expected time of contact of the next cutter. Tool touch is declared when an above-threshold signal occurs during the window; the milling logic is reset by a noise spike in the interval before the window starts. The basic logic detects tool touch in a dense spiky noise situation.

Abstract: An acoustic tool break detector monitors vibration caused by a cutting process and has an analog amplifier to condition the signal, then searches for a rapid sustained change in signal level indicative of a cutting tool break. An automatic gain control circuit dynamically controls the gain of the analog amplifier and adjusts the output cutting noise signal to a desired average level during an active cut while allowing use of such a break algorithm. The time rate at which the AGC changes gain is constant and independent of gain; it is set such that a gain change of 2:1, for instance, takes longer than the confirmation period for a tool break. The analog amplifier has a variable attenuator whose gain is set by the outputs of an up/down counter; these outputs are fed back to a variable clock whose rate is dependent on gain at any instant. The clock outputs drive the counter until the analog cutting noise signal is within a preselected window.

Abstract: A rotating body, for example a chuck (10) comprises a sensor (56), a signal processing unit with amplifier and a plurality of transmitting diodes (14) and receiving diodes (16) peripherally spaced in a radial plane, in which also a stationary transceiving station (18) is arranged. The sensor (56) detects special working conditions of a tool clamped in the chuck (10). Signals of sensor (56) are fed to the signal processing unit. Sense commands transmitted from the transceiving station (18) via receiving diodes (16) are processed in the processing unit during rotation of the chuck (10) and corresponding working condition signals are transmitted from the transmitting diodes (14) back to the transceiving station (18).

Abstract: To monitor machines for breakage and/or wear of the tool, the vibrations produced by dynamic forces generated by the machine parts are measured in the range of the natural frequency of the machine above the operating frequencies. The measured values are compared, as the desired states or conditions, with the respective momentary vibration behavior of these measuring locations and frequency ranges (i.e., the actual operating state or condition), and whenever there is a deviation of the actual state from the desired state by a given threshold value, a signal is emitted which may be used to shut down the machine.

Abstract: The vibration of an end mill (36) is sensed by either microphones (42, 44, 46) or accelerometers (78, 80, 82). A time domain signal is produced by these sensors which is converted into a near-real time frequency spectrum. A certain frequency band in the spectrum is directly related to end mill vibration and certain frequencies in the band will change in amplitude corresponding to certain types of end mill wear. When any of the amplitudes in the band exceed a certain threshold limit the end mill is known to be dull.

Abstract: A device-implemented method for monitoring the cutting condition of a machine tool during machining of a workpiece senses acoustic emissions resulting from the machining of the workpiece, produces an electrical signals which varies in accordance with changes in the sensed acoustic emissions, and variably amplifies the signal by a gain level selected by a set of digital data stored in the memory (12) of a computer (15). The signal is amplified by an amplifier (32) having a variable gain input (34) controlled by the computer (15). The signal is processed by two circuits (36, 40, 56 and 36, 42, 50) which respectively generate two separate sets of digital data representing the cutting condition of the tool. The computer (15) compares the data with memory-stored information to determine whether an alarm signal should be generated. A circuit (75) is provided for generating a control signal indicating that cutting of the workpiece has commenced.

Abstract: In some machining conditions the background noise in an acoustic cutting tool break detection system is a low mean level with fairly dense high amplitude noise spikes. A common tool break vibration signature is the sudden appearance of a dense spiky noise. Digital signal pattern recognition logic uses an up/down counter to reject the noise on the basis of its lower spike density while alarming on such a tool break signature. Preprocessed vibration signal samples are tested against a detection threshold and an alarm generated if those whose amplitude is above the threshold amplitude exceeds those below by a preset count.

Abstract: Vibrations at the cutting tool-workpiece interface are sensed and the accelerometer output is preprocessed to yield a cutting noise vibration signal. Digital analysis of the sampled signal is performed to detect a gradual cutting noise signal level decrease tool break signature, either continuously decreasing or decreasing in a series of small abrupt steps. A tool break alarm is generated, without false alarming on metal-to-air tool path transitions, as the mean cutting noise signal level falls below an upper check limit and, after a preset time has elapsed, crosses a lower check limit.

Abstract: The air gap between a rotor and a stator in rotating electrical machinery is determined using sonar techniques. An ultrasonic signal transmitter and receiver are mounted on one of the rotor and stator for transmitting ultrasonic signals to the other of the rotor and stator and receiving reflections therefrom. The time between signal transmission and reflected signal reception is determined, and the spacing of the rotor and stator is determined from the time, the velocity of sound, and the speed of rotation of the rotor.

Abstract: A Machine Tool Monitor detects the sudden increase in vibration signal level when a slowly advancing cutting tool first touches the workpiece. The delay to a tool touch decision is reduced while still avoiding false alarms on high amplitude single-peaked and multi-peaked noise spikes. Samples of the preprocessed analog vibration signal that are above a low threshold level are analyzed by digital tool touch detection logic. The signal slope polarity is determined by comparison of a new sample to the tracking mean, or by sample-to-sample amplitude comparisons, and presented to an up/down counter. A tool touch alarm is generated when the positive slope counts exceed the negative slope counts by a preset number slightly greater than occur in a time period from the start of a noise spike until its peak amplitude is passed.

Abstract: A motion sensor unit which includes a sensor assembly for monitoring whether or not the inclination of a mobile member is in excess of a predetermined reference angle and outputting a pulse signal in case the inclination is greater than the reference angle; a detector for monitoring whether or not the duration of the pulse signal is in excess of a predetermined reference time and, in the case of any excess, outputtting a signal representing that the inclination of the mobile member is greater than the reference angle and is continuous for more than the reference time; a sensor assembly for outputting a pulse signal inverted in accordance with the value of a shock given to the mobile member; and a detector for monitoring whether or not the cycle of the pulse signal is shorter than a predetermined reference time and outputting a shock detection signal when the cycle is shorter than the reference time.

Abstract: A vibration monitoring apparatus for monitoring vibrating conditions of a plurality of rotary machines comprising a signal processor for processing actual data relative to levels of vibrations of the rotary machines and a control processor for storing in memory reference data relative to selected rotational frequencies and corresponding alarm levels for the rotary machines. The vibration waveform of one vibration sensor selected by a scanner is converted by an A/D converter into digital data to be supplied to the signal processor through a shift register. The signal processor is operated under program control to determine the peak-to-peak magnitude of the vibration waveform and compares it with the alarm level provided from the control processor.

Abstract: An improved vibration monitoring system and apparatus are disclosed for monitoring rotating shafts, as in motors, pumps, blowers, generators, etc., and signaling the occurrence of an unsafe condition. The apparatus includes a vibration monitoring probe assembly of improved design which is mounted adjacent to a rotating shaft and to the method of attachment thereon. The probe assembly is supported on the fixed housing of the rotating shaft in insulated relation thereto and includes a probe element in spaced relation to the shaft for contact therewith upon occurrence of excessive vibration. A signal conditioner mounted near the probe assembly provides power to the probe and processes the signal and transmits it to the monitor. A remote monitor is provided which indicates excessive vibration in response to a signal from the probe. An electronic circuit is provided which detects and registers the excessive vibration on the monitor through a visual and audible alarm.

Abstract: An apparatus and method for tool condition and failure monitoring system for predicting imminent tool failure by sensing acoustic emissions from a cutting operation converting the emissions into an electrical signal filtering the electrical signal and using a "count rate" technique on the filtered signal to generate a signal indicative of imminent failure. To improve the prediction, the filtering includes removal of low frequency and d.c. signals and the imminent failure is indicated only after several successive periods of a triggering level of count rate.

Abstract: An apparatus and method for monitoring the inclination of a motor vehicle, measures the inclination during successive time periods with an inclination-sensitive sensor to produce measured signals; converts the measured signals to digital form; averages the digital signals during an initial predetermined time period to form an original reference signal; stores the original reference signal; compares subsequent digital signals to the reference signal to form a deviation signal which is used for triggering an alarm when a plurality of the digital signals deviate from the reference signal by more than a predetermined tolerance value; the reference signal being continuously updated by averaging subsequent digitized measured signals at plurality of times during subsequent time periods to form updated reference signals; storing each updated reference signal in place of a previously stored reference signal; providing an oscillation window to prevent triggering of the alarm during natural oscillation of the vehicle.

Abstract: Acoustic transducers are attached to each of the drill bits which produce electrical output signals in response to the vibrations during the drilling operation. A plurality of output signal includes waveforms having an amplitude and frequency dependent upon the condition of the drill bit and the medium being drilled. The waveforms represent the acoustic signature produced by the drilling operation. A control unit simultaneously compares the acoustic signature of each of the output signals with a reference signal by comparing the waveforms to determine if an improper drill condition exits. When drilling through a multilayered workpiece such as a printed circuit board having layers of different types of materials, the acoustic transducers will produce an output signal having a sequence of waveforms representing the acoustic signatures of the sequence layers. The control unit counts the number of waveform occurrences for each particular type of layer and indicates when a predetermined level is reached.

Abstract: A failure detector detects breakage in a machine tool cutting element, such as a drill bit, by use of a accelerometer supported against a workpiece being operated on by the cutting element. Vibrations are induced in the workpiece by the cutting operation, the vibrations having spectral components in the audio frequency range which are characteristic of proper operation of the cutting element, the spectral components changing upon a breakage of the cutting element. A voltage produced by a positioning mechanism of the cutting element identifies the location of the cutting element relative to the workpiece. A bandpass filter separates the spectral components associated with proper operation from spectral components associated with faulty operation. Logic circuitry signals the joint occurrence of the spectral components of proper operation with the position of the cutting element at the site of the workpiece so as to permit the signaling of a cutting tool failure during operation on the workpiece.

Abstract: Substantial cutting condition changes that occur gradually, as opposed to the more usual sudden large change, are detected by setting upper and lower cutting noise mean level thresholds. When the mean cutting noise exceeds the upper threshold or stays below the lower threshold for a preset number of signal samples, a tool break alarm is generated. Techniques are given to reduce false alarms at the start and end of the cut and on runout on initial rough surface cuts. The system comprises an accelerometer or other sensor whose signal is preprocessed to attenuate lower frequency machinery noise and detect the signal energy in a band below 100 KHz, then sampled, and the digitized signal samples analyzed by pattern recognition logic.

Abstract: A system and method for monitoring vibrations of a cutting tool produced by tool break events, and for interpreting them to detect tool breaks of sufficient magnitude to endanger the machined part. The signal generated by a sensor such as an accelerometer is preprocessed to attenuate low frequency machining noise and detect the energy in a higher frequency band, then sampled, and the digitized signal samples analyzed by tool break detection logic. This logic is triggered by a positive-going signal transient, and prevents false alarms on minor tool break events that do not mar the workpiece and on noise from other sources.

Abstract: This tool break detection system relies on monitoring changes in the cutting noise itself, rather than detecting the tool fracture acoustic signal. A broken tool capable of damaging the workpiece is detected, and tool break events that do not affect cutting conditions are ignored. The signal from a sensor such as an accelerometer is preprocessed to attenuate low frequency machinery noise and detect the signal energy in a band below 100 KHz, then sampled, and the digitized signal samples analyzed by pattern recognition logic. Runout false alarms during rough surface cutting are prevented; after detection of an abrupt increase or decrease in signal level, the confirmation period to test for a persistent shift in mean level is set longer than the workpiece revolution period.

Abstract: A sonic detector for security applications or the like includes a digital sampling circuit which converts sound waves into digital pulses and stores the pulses in a counter that is periodically reset by a timing circuit. If a predetermined number of pulses are accumulated in the counter before the counter is reset, an alarm signal is generated to energize an alarm. The duration of the pulses may be altered to compensate for the effects of reflected sound which vary depending on the ambient acoustical environment. The number of pulses required to generate an alarm signal may be preprogrammed in accordance with the type of sounds to be detected. An anti-defeat circuit converts a continuous sound wave to the required number of digital pulses for generating an alarm.

Abstract: There is dislosed a vibration telemetering system capable of measuring adverse vibrations of installations or equipment in a plant such as a nuclear power plant. The system includes a vibrometer which measures the vibrations in a non-contacting fashion. The direction at which the vibrometer faces is adjusted by an angle adjusting mechanism which is mounted on a travelling unit running along a predetermined inspection route in the plant. A measured signal from the vibrometer is transmitted to a remote control room through a communication system and is used for evaluating whether or not the state of the plant is normal. The remote control room can control the travelling unit and the angle adjusting mechanism through the communication system in order to monitor the vibrations of a plurality of places along the predetermined inspection route.

Abstract: An apparatus monitoring the vibrations of a rotary machine precisely at all times. In a control processor, a rotational frequency is calculated with a data signal from a register which operates on the basis of period pulses from a key phaser, while a vibration level corresponding to the rotational frequency is read out of a memory, and an alarm level obtained by giving the vibration level a constant from an alarm level setting unit is sent to a signal processor. The vibration waveform of a vibration sensor selected by a scanner is converted by an A/D converter into a digital signal, which is applied to the signal processor through a shift register. In the signal processor, the alarm level from the control processor is compared with vibration data from the shift register, and the calculated result is sent to the control processor. The control processor operates output appliances on the basis of the information from the signal processor.

Abstract: Acoustic waves are sensed in contact with or near the plant at at least two points (1, 2, 3, 4) whose position is accurately determined with respect to the monitored region. The order of arrival of the acoustic waves at the sensing points (1, 2, 3, 4) is determined and this order is compared with a predetermined order corresponding to a phenomenon occurring in the monitored region. An alarm is triggered if the order of arrival corresponds to the predetermined order. The apparatus includes an encoding logic (9), a comparator (10) and a monostable circuit (12) triggering the alarm. The invention is particularly applicable to monitoring nuclear reactors in operation.

Abstract: An apparatus for controllably delivering power from a device to a workpiece is useful, for example, in performing qualitative material tests on various materials. In the instant apparatus, a sonic generator means controllably supplies sonic power to a workpiece, causing the surface of the workpiece to erode. A sensing means produces an actual power signal having a magnitude responsive to the power consumed by the sonic generator means. A settable means produces a desired power signal, and a control means compares the desired and actual power signals and supplies motor control signals in response to the respective magnitudes of the power signals and to a tracking time interval signal. In response to termination of the tracking time signal, the control means blocks the motor control signals. A motor means controllably moves the sonic generator means relative to the workpiece in response to receiving the motor control signals.

Abstract: A blur detecting device comprises a plurality of photo-electric converter elements which are arranged in different positions to receive light from an object and to convert quantities of light received into quantities of electricity. Electric charge storing elements are included which store the quantities of electricity obtained from the photo-electric converter elements. A computing circuit in the blur detecting device obtains the ratio of the quantities of electricity stored at the electric charge storing elements. An indicating circuit compares signals produced from the computing circuit at different lengths of light receiving time and indicates a blurred state of the light received from the object.

Abstract: Constant or transient forces and displacements between a motion snubber and its associated load are detected and converted to an electrical signal. Electrical signals from the detection devices are transmitted to a receiving device which is electrically connected to a recording means. The signals from a plurality of detecting devices are encoded to identify the snubber having the detected force and displacement.

Abstract: In a vibration level indicator of the type having a vibration transducer and means for determining the average vibration level, the improvement having a storage element for holding a reference value corresponding to a selected level of the vibrations, and compare and display means responsive to the storage element and the transducer for indicating the relative relationship between the average level and the selected level.

Abstract: A worn tool detector system for analyzing input signals from a sensor were the signal is in the form of an analog waveform exhibiting periodic impulses exceeding the average amplitude thereof as the tool wears. A microprocessor controlled variable gain amplification network is utilized to normalize the average waveform amplitude to a fixed level. During machine operation, impulses are detected by comparing the sensor waveform to a programmable selected ratio of the normalized level. When a given number of successive impulses are received the microprocessor generates a warning signal which may be used to retract the tool. An adaptive mode is disclosed wherein the sensor waveform throughout the course of the machining operation is repetitively normalized to adjust for different sensor waveform amplitudes.

Abstract: A transducer selecting system for use in a noisy environment can operate in a vibration monitoring system using a data processor. Narrow band signals representing transducer information at selected frequencies of interest are subtracted from broad band signals representing information and background noise. The magnitude of the background noise components of each transducer is used to select from among duplicative transducers or to signal potentially unreliable information.

Abstract: In a tumbling hammer type rapper (10), a feedback signal is provided via limit switch (30) and cam (28) mounted on rapper shaft (14) to control the rotation of rapper shaft (14) through one revolution. Rapper shaft (14) rotation is monitored to ensure that rapper shaft (14) completes one revolution, returning to the initial position, within a normal predetermined time period. If rapper shaft (14) fails to rotate from the initial position or fails to complete one revolution within the normal predetermined time period, an alarm is energized.

Abstract: An offshore drilling tower has at least one upright hollow member extending from below the water to support an above-water platform. A detector in or on the hollow member, usually below the water, responds to a water leak into the hollow member. The detector includes a signal generator responsive to pressure or chemical effect of the water. The detector is effective when actuated by water intrusion into the hollow member and into contact with the detector to send a signal of a unique or distinct frequency through the member itself to a signal receiver, preferably on the platform. The receiver is tuned to the distinct frequency and is effective upon receipt of such signal to afford an indication that the detector has been actuated by a water leak at a particular location.

Abstract: When a drill is overloaded, while cutting a hole in a workpiece, a torque limiter disconnects the drill from a main spindle. As the drill is disconnected from the main spindle, the torque limiter generates high-level elastic waves. The elastic waves are converted by a transducer into a voltage signal. The level of the voltage signal is compared with a threshold value.

Abstract: An alarm device comprises a blocking oscillator circuit composed of a transformer and a transistor and a sound emitter using a piezoelectric effect exhibiting element and interposed between one end of the secondary coil of the transformer and a power source, with the other end of the secondary coil connected to the base of the transistor. When the sound emitter receives a slight vibration, it generates an electromotive force, which is applied to the base of the transistor. Consequently, the blocking oscillation circuit oscillates and causes the sound emitter to issue an alarm.

Abstract: A shaft vibration evaluator employs measured displacement of a shaft in the vicinity of a bearing together with known or measured shaft eccentricity to calculate the dynamic bearing load so that damaging loads can be avoided. Shaft vibration or motion is assumed to be elliptical having major and minor axes which are inclined at angles with respect to the bearing displacement sensors. The magnitude of the major and minor axes and the angular displacement are calculated from the measured parameters and provide one set of inputs to the load calculator. Bearing eccentricity can be calculated from a knowledge of shaft speed, lubricant temperature and known bearing geometry. For a given eccentricity, a set of four damping coefficients and four spring coefficients of the bearing may be derived. These coefficients are the remaining inputs to the dynamic load calculator.

Abstract: A vehicle equipped with a spring and shock absorber suspension has a piezoelectric wafer interposed between the spring and a part of the vehicle in such manner as to cause the wafer to be subjected to a compressive or decompressive force in response to relative vertical movement of the vehicle part and the suspension. The application of such force to such wafer results in the generation of an electrical current pulse which is transmitted to an indicator mounted within the vehicle in a position to enable the driver to monitor the condition of the shock absorber.

Abstract: A data acquisition system utilizing a microcomputer and incorporating a plurality of monitors each adapted to produce an electrical signal indicative of a physical condition of apparatus to be monitored. The electrical signals are fed via multiplexing equipment and analog-to-digital converters into the microcomputer which is equipped with print-out means. The system is such that the level of any one or all of the signals from the respective monitors can be printed out as well as a change in the condition of any signal. Means are incorporated into the computer for calculating and printing the trend (i.e., the slope of a plot of signal amplitude versus time) of a succession of stored signals from any monitor which would indicate a probable malfunction of a device being monitored and the probable time to failure. In the case where the signals from the monitors comprise, vibration signals, the system performs an automatic frequency spectrum analysis whenever a probable or actual malfunction is detected.