Abstract: An ultrasonic edge detector system wherein the lateral position of a moving web or sheet is monitored by projecting an ultrasonic beam from a transmitting transducer toward a receiving transducer and the web edge occludes or shadows more or less of the ultrasonic beam changing the ultrasonic energy received by the receiving transducer. Changes in output of the receiving transducer are detected as a measure of change in edge position. Accuracy in the measurement of the position of the edge is achieved by lengthening the path of acoustic energy from the transmitting transducer to the receiving transducer by positioning an acoustic reflector in said path. Reverberations are reduced by causing the angle of incidence of the ultrasonic beam to be at an angle .alpha. of greater than 0 degrees. A dual receiving transducer system is disclosed compensating for fluctuations in power to the edge detector system.

Abstract: A transit time gas flow meter comprising a pair of transducers mounted at an oblique angle to a gas flow in a duct for measuring transit time of an ultrasonic pulse in both directions between the transducers and a computer to determine the difference between transit times as a measure of the velocity of a gas stream flowing in the duct. Each transducer is carried in a mounting assembly which is comprised of a U-shaped frame member having a base and leg members and an ultrasonic reflection surface formed on the base of a U-shaped frame member. A transducer is mounted between said legs and at a reference target carried on the U-shaped frame member and is positioned at the edge of the gas, and the ultrasonic transit time to each said reference target is subtracted by the computer means from the transit times from each transducer to the other transducer, to zero flow calibrate the transit time flow meter and to improve the accuracy measurement.

Abstract: A system for locating the edges of a moving strip of material having two edges. In one embodiment, a pair of ultrasonic transducers are positioned above the path of the moving strip and oriented at acute angles relative to the surface of the strip. A circuit for causing each of the transducers to emit ultrasonic pulses in the direction of the two edges, respectively, a detector circuit connected to the ultrasonic transducers detects acoustic diffractions caused by the edges, respectively, and compares the times of detection of the acoustic diffractions to locate the positions of the edges relative to the pair of transducers. A microprocessor controls operation of the transducer and receiving signals therefrom and computes one or more of the following quantities: 1) the distance D.sub.1 from the transducer to the near one of said two edges, 2) the distance D.sub.2 from the transducer to the other of the two edges, 3) the distance to the center of the strip from the transducer D.sub.c =1/2(D.sub.1 +D.sub.

Abstract: A capacitance-type ultrasonic transducer is disclosed in which a thin insulating plastic film or membrane is coated on one side with a thin film conductor, such as gold, and the back or counter electrode is comprised of a gas permeable conductor material such as sintered bronze. Springs are utilized to apply pressure to maintain good electrical contact between the gold film side of the membrane and an annular conductor. Signals are applied to and taken off of the gas permeable conductor backplate. Due to the porous structure of the back electrode and the gas permeability thereof, variations in ambient presure on the membrane or film are equalized. Ranges of operating freqeuncy can be established by size of particles used to form the sintered electrode.

Abstract: A transit time gas flow meter comprising a pair of transducers mounted at an oblique angle to gas flow in a duct for measuring the transit time of an ultrasonic pulse in both directions between the transducers and computer determines the difference between transit times as a measure of the velocity of a gas stream flowing in the duct. Each transducer is carried in a mounting assembly which is comprised of a U-shaped frame member having a base and leg members and an ultrasonic reflection surface formed on the base of U-shaped frame member. A transducer is mounted between said legs and at a predetermined oblique angle to said reflection surface. A reference target carried on the U-shaped frame member is positioned at the edge of said gas and the ultrasonic transit time to each said reference target is subtracted by the computer means from the transit times from each of transducer to the other transducer, respectively, to zero flow calibrate transit time flow meter and to improve the accuracy measurements.

Abstract: A shear mechanism is controlled by ultrasonically calipering the bar stock and adjusting the length of sheared bar stock to assure a uniform volume of metal bar stock in the sheared product. A plurality of ultrasonic transducers are carried in a common frame and centered on the bar stock using the same ultrasonic calipers.

Abstract: Hot target ultrasonic measurement system in which an ultrasonic transducer for transmitting ultrasonic energy along a measuring path toward the hot steel ingot target receives a reflection echo of ultrasonic energy from the hot target along the measuring path, and electronic circuit for determining the range to the hot target from the time of transmission of said ultrasonic energy to the receipt of reflection of ultrasonic energy from said target. The temperature or speed of sound in the media in the measuring path is measured and used in the range measurement.

Abstract: An ultrasonic apparatus for measuring the speed of sound in a gaseous medium comprises a chamber in which an ultrasonic transducer is mounted at one end of the chamber and first and second ultrasonic reflecting surface are mounted at the opposite end of the chamber with a temperature insensitive mounting member for mounting the second ultrasonic reflecting surface at a predetermined distance closer to the ultrasonic transducer than the first ultrasonic reflecting surface and a circuit connected to the transducer for converting ultrasonic energy reflections from the first and second reflecting surfaces to a signal corresponding to the speed of the ultrasonic energy between the two ultrasonic reflecting surfaces. Thus, the distance from the transducer to the targets is not relevent - only the distance between the two reflectors which is established by the temperature insensitive mounting member is relevant.

Abstract: An ultrasonic measuring transducer system in which an ultrasonic transducer transmits an ultrasonic pressure wave and receives a return echo from a target and an electronic circuitry means converts the received pulses to arrange information to a target. The ultrasonic transducer is mounted in a wall of a plenum chamber. Air flow passages or apertures surround the ultrasonic transducer and air from a supply under pressure is connected to said plenum chamber. A temperature (or velocity of sound) measuring device is mounted in the plenum chamber for measuring the temperature from which the speed of sound in the medium is determined, and a measuring chamber forming tube surrounding the transducer and air outlet apertures provide a space in which air flow is maintained at a relatively constant rate and the temperature in substantially all of the measuring path and space between the target and said ultrasonic transducer is essentially the same as in the plenum chamber.

Abstract: An ultrasonic sensor system particularly for automatic door openers of a swinging door type, in addition to sensors (14) for people approaching a door for controlling opening and closing purposes, has at least one microprocessor controlled ultrasonic beam transducer (40, 41) for projecting an expanded unidirectional ultrasonic beam in a selected detection zone in the path of the swinging door and an ultrasonic detector for converting reflected ultrasonic beam energy into an analog electrical signal which constitute an acoustical image of objects in and bounding the selected detection zone. This acoustical image is stored or, a number characterized thereof is stored and this acoustic image is then compared with a later acoustical image of an object in the selected detection zone and then the comparison is used to signal a lack of correlation between the first and second acoustical images to produce a signal preventing operation of the door opening.

Abstract: An ultrasonic sensor system particularly for automatic door openers of a swinging door type, in addition to sensors (14) for people approaching a door for controlling opening and closing purposes, has at least three microprocessor controlled ultrasonic beam transducer (40, 41, 42) for projecting expanded unidirectional ultrasonic beams in a selected directions in a detection zone in the path of the swinging door and ultrasonic detector for converting reflected single multiple path ultrasonic beam energy into an analog electrical signal which constitute an acoustical image of objects in and bounding the selected detection zone. This acoustical image is stored or, a number characteristic thereof is stored and this acoustic image is then compared with a later acoustical image of an object in the selected detection zone and then the comparison is used to signal a lack of correlation between the first and second acoustical images to produce a signal preventing operation of the door opening.

Abstract: A sound wave position digitizer has a pair of sound wave beam transducers, each spaced a predetermined distance from the edges of a data surface such that the beams intersect on the data surface at substantially orthogonal angles. The beams are folded by reflectors to achieve compactness and, to further improve the form factor, the beams are coupled to the folding reflectors by acoustic horns which intersect and have a common section.

Abstract: An ultrasonic transducer is comprised of a stack or sandwich of electrostrictive elements, an energy reflecting mass at one end of the column or stack of electrostrictive elements and a pair of laminar plates sandwiching a honeycomb core to constitute an extremely rigid, light mass member contacting a fluid medium in which ultrasonic energy is to be introduced. The output member is characterized by having a high shear modulus and a low density at the opposite end for efficiently coupling the ultrasonic energy into the fluid medium, particularly air and has a narrow beam and a very long range.

Abstract: An ultrasonic apparatus for determining the amount of liquid in a container of known volume includes at least a pair of ultrasonic transducers which are mounted a known distance apart relative to the liquid surface so that the ultrasonic energy reflected from the liquid surface traverses the following paths: (1) from a first of the transducers vertically to the liquid surface, and (2) from the first transducer to the liquid surface and then to the second transducer. A circuit measures the time of travel T corresponding to path (1) above, and T1 corresponding to one-half the travel time of path (2) above. The height H of liquid above the transducers is determined by solving the equation: ##EQU1## where S is the known distance between transducers, T is the travel time of ultrasonic energy directly or vertically to the liquid surface and T' is one-half the travel time between the two transducers reflected off the liquid surface.

Abstract: A method and the apparatus for management information and control for restaurants is disclosed. The apparatus includes a plurality of remote units carried by waiters. The remote units are provided with a keyboard, a display and a memory. The remote units may simply be radio frequency transmitters capable of being interrogated, but are preferably radio transmitters and receivers. A central interrogator transceiver periodically interrogates each of the remote units after which the remote units transmit information back to the central interrogator transceiver. The central interrogator transceiver couples the information transmitted thereto to a central processor having a high speed memory therein. The central processor operates on the information received to provide order information to a kitchen display, an order assembly display, a service bar display, a table status display and to a check printer-cash register unit.

Abstract: A low cost, efficient, ultrasonic transducer and method comprises a narrow beam electrostatic transducer and a beam transformer operated in air for expanding the emitted beam of the electrostatic transducer relative to a single axis. The beam transformer is a sonic reflecting surface spaced from the ultrasonic beam generator and within the near field thereof and having a geometric surface in which all points of said surface are generated by the revolution of a line about a fixed axis which is normal to the plane of the electrostatic transducer. A partial surface of a cone, the axis preferably being offset from the axis of the narrow beam electrostatic transducer and placed in the near field thereof transform the narrow beam to a broad beam with the beam transformer being an effective coupling element for the emitted beam and the return echo for ranging systems which are both efficient and easy to produce and do not have significant alignment problems.