Abstract: A shoe (1) is provided which includes two housings designed for receiving ultrasonic probes (2) of which the vertical position with respect to the track is adjustable via two pressure cylinders (9). The shoe (1) is connected via two pressure cylinders (13) to a frame (12, 22, 23) designed for mounting under a railway vehicle. The shoe (1) is guided and driven along the track by deformable rings (14). Conduits (15, 16) are arranged in the body of the shoe (1) in such a manner as to allow the supply of a fluid in front of the probes (2) and the recovery of one part of this fluid behind said probes (2). Cleaning shoes (30, 30') and high pressure sprayers (31, 31') clean the track in front of the measuring carriage.

Abstract: An adaptive scanning technique for ultrasonic testing of materials utilizing a realtime lift off detection system. The technique recognizes characteristic reflected/generated signals of partial and total lift off occurrences, wherein the ultrasonic transducer is separated from the surface of the test material. Once recognized and analyzed, these characteristic reflected signals are correlated with parameter changes preselected to compensate for such partial or total lift off occurrences. These parameter changes are communicated to a mechanical positioning system that alters the position, scanning speed, and vertical force with which mechanical compliance of the transducer is maintained with the test material.

Abstract: A method and an apparatus for measuring and then controlling the refracted angle of ultrasonic waves propagating through a component. The method directly measures the actual refracted angle of ultrasound in an industrial component while performing nondestructive examination by measuring the slopes of characteristic echo-dynamic lines. These slopes are related to the angle of refraction by a simple mathematical relationship. A pattern recognition filtering method is used to identify the echo-dynamic pattern. The slope of an echo-dynamic line is computed after an edge detection algorithm is applied to the data.

Abstract: A method and apparatus for ultrasonically testing sheet material comprising rotating at least one ultrasonic sensor, mounted on a rotatable test head, about an axis of rotation substantially normal to the plane of the sheet material as it moves therepast.

Abstract: A rotor of on ultrasonic testing device for rotation-symmetrical test-pieces has drillings arranged in pairs for test head supports and test head supports arranged in these drillings. These supports are longitudinally adjustable along the axis of the drilling. The supports are sealed in the drilling and carry at least one test head. The drillings arranged in pairs are arranged in staggered array along the axis of rotation of the rotor or around the periphery of the rotor. Each pair has a rotary drive which as a shared activating system and facilitates synchronous rotation in an opposite direction of the two test head supports of the pair around the axis of the drilling.

Abstract: A scanning tunneling microscope, in which the gap between a tip having a keenly sharpened end and a sample is narrowed to let flow a tunneling current between them and thereby allow observation of the surface of the sample, a strain wave detecting device is disposed on the sample or in the vicinity of the sample to detect strain waves generated within the sample. By modulating the value of the above described tunneling current, strain waves are generated within the sample. The strain waves are detected by the above described strain wave detecting device. On the basis of the amplitude information and phase information of detected strain waves, physical information regarding the inside of the sample is obtained.

Abstract: Presented is a method and apparatus for inspection through use of a variable angle ultrasonic transducer of metallic members such as pipes, conduits, plates and other formed metallic members normally having a surface regularity adhering to a predetermined standard of normalcy. Inspection proceeds in such a manner that irregularities in the surface of the member under test that lie outside the standard of normalcy are sensed, the degree of irregularity determined and converted into an electrical signal that is applied to continually variably control the angular relationship of the ultrasonic transducer with the surface of the metallic member being inspected whereby abnormalities within the metallic member may be reliably and accurately detected, displayed and recorded.

Abstract: A method and apparatus for use in confirming hydrogen damage in a boiler tube comprises a pair of electromagnetic acoustic transducer coils which are mounted for movement toward and away from each other. An electromagnet produces pulses that generate acoustic beams across a chord and within the wall thickness of the boiler tube. For adapting to boiler tubes of different outside diameters, the transducers coils are mounted on a resilient member so that the coils can be pressed against the outer surface of coils having a variety of outside diameters. The angle of the acoustic beam between the coils must also be adjusted, however, and this is done by changing the frequency of energy applied to the coils.

Abstract: The distance sensor means and the ultrasonic probe are integrally coupled to each other in such a manner that a preceding scanning line to a current scanning line which is scanned by the ultrasonic probe is scanned by the distance sensor means, and the shape-measurement scanning operation of the distance sensor means and the flaw-detection scanning operation of the ultrasonic probe are performed in parallel with each other. A flaw detection area is divided into plural sub-areas, and plural storing areas are arranged in a mesh form in one-to-one correspondence to the sub-areas, only one shape information of position storing area including the flaw detection area being stored in each of the storing areas. The position and orientation of the ultrasonic probe at each flaw detection point is controlled using the stored shape information.

Abstract: In a process for ultrasonic testing of elongated, prism-shaped sections (22) with at least one planar outer surface (54) extending along the longitudinal axis (26) of the section, with the objective of detecting material defects or verifying geometric data, the section (22) to be tested is exposed to ultrasonic beams from several ultrasonic probes (28 to 34) installed in a probe carrier (44). The section (22) is moved along its longitudinal axis (26) in relation to the probe carrier (44). The latter is installed in the rotor (20) of a rotary testing machine which rotates around the longitudinal axis (26) of the section (22).

Abstract: The invention is a compact ultrasonic tester involving rotating sensors. The processor rotates with the sensors so that the output signal of the processor goes through the slip rings, rather than the output signal of the sensors. A spraying system is incorporated in conjunction with rollers. The rollers take the applied spray on the pipe surface and paint a film on the outer pipe surface to allow a good contact for meaningful results. A floating shoe is provided for holding each sensor against the pipe wall. The sensors are biased into contact with the pipe surface and the machine can handle different diameters of pipe. By controlling the pipe speed of advance and the rotational speed of the sensors, 100 percent coverage of the pipe wall is assured. The machine is compact and can be installed behind existing electromagnetic/gamma testers without major modifications to pipe-testing facilities.

Abstract: A process and apparatus for identifying defects within the structure of a tubular sleeve used to make toothed belts, the sleeve, having a toothed inner surface 2a, is operatively mounted on rollers 5, 6 operable in rotation to move the sleeve transversely to the extension of the teeth 3. An ultrasonic emitting and receiving member 15 movable parallel to the rollers 5, 6 detects the presence of structural cavities 3a in the sleeve. An electronic processing unit 20 carries out the identification and memorization of the position of the structural cavities 3a on the longitudinal extension of the sleeve 2.

Abstract: Ultrasonic apparatus that automatically adjusts the focus of ultrasonic waves to a desired depth within an object includes an ultrasonic probe which irradiates a focused ultrasonic beam onto an object to be inspected and a receiver which receives ultrasonic waves reflected from the object. A desired focusing depth is set and the inherent focal length of the probe and the velocity of sound within the object are detected to evaluate a distance between the probe and the object at which the focus of the probe coincides with the desired depth. The distance between the probe and the object is adjusted to coincide with the evaluated distance.

Abstract: A method and system for nondestructively testing in a continuous sequence a multiplicity of railroad track crossties of wood or concrete to determine the condition and life expectancy of each of the crossties and of the track as a whole. The system includes an electric pulse generator and a pair of transmitting and receiving transducers, which transducers are adapted to be brought into moving contact with the crossties at respective locations straddling desired test regions thereof, for example, the regions under a tie plate, for sending sonic mechanical pulses through that region of the crosstie from one transducer to the other. If desired, three pairs of transducers may be provided for simultaneously straddling both tie plates and a medial reference zone on each crosstie. The transducers and the pulse generator are carried by a vehicle riding on the track rails, along with a computer for processing/evaluating/storing/reproducing the test data.

Abstract: An ultrasonic inspection system uses a submerged ultrasonic transducer to provide an ultrasonic beam focused to a small spot on a submerged surface of a member to be internally inspected. By use of a focused beam projected through a fluid, such as water, to a submerged surface, the ultrasonic energy is efficiently coupled to a surface area which may be small and/or of irregular or curved shape. Systems and methods for inspecting turbine rotor blade tenons permit a turbine rotor with hundreds of blades to be rotated past a submerged transducer with automatic recording and processing of ultrasonic echoes to develop two-dimensional color images of internal portions of tenons at which cracks may typically occur. Automated adjustment of beam focusing of a transducer including an array of elements and threshold monitoring of fault-indicative echo returns are provided for.

Abstract: A method and apparatus for distinguishing between hydrogen damage in the wall of a boiler tube, and surface damage on the inside surface of the tube, comprises a pair of transducers which are spaced on the outer surface of the tube and which apply a refracted shear ultrasonic wave through a chord of the tube with a beam angle that is calculated from the outside radius and wall thickness of the tube. The transducers are first applied to an undamaged tube and an instrument connected to the transducers is adjusted to 80% of full screen height. The same transducers are then, applied to a suspected boiler tube. Any attenuation of the initially high amplitude below 12 dB indicates hydrogen damage as opposed to inner surface damage which has been found to produce a far lower attenuation.

Abstract: This invention pertains to a method and apparatus of non-destructive testing wherein a generally bidirectional wave generating electromagnetic acoustic transducer is pivotally mounted upon a base with this transducer being continuously rotated or oscillated upon the base as it is moved with respect to the workpiece (or the workpiece is moved with respect to the base). This oscillation or rotation causes a wave to be generated along an arc with these waves extending radially outward from the base so that any flaws in the workpiece can be struck at an angle as close to 90 degrees as possible (the optimal incident angle).

Abstract: A rod positioning apparatus is disclosed for positioning the end of a rod for a subsequent work operation on the rod such as ultrasonic testing of the rod end. A rod stop member receives the end of a rod advanced into a rod working position. A light emitting diode emits light through a fiber optic cable and across the area a rod end occupies when positioned in a rod stop position of the rod stop member. The end of a fiber optic cable receives light emitted across the rod stop position and directs the light to a light sensor. A control is activated when the light is not sensed on the light sensor and is activated for controlling a rod advancing and securing mechanism for stopping further advancement of the rod and securing the rod in a fixed position when the rod has advanced into the rod stop position and blocked light emitted from the light emitting diode through the fiber optic cables and onto the light sensor.

Abstract: A scanning tunneling microscope, in which the gap between a tip having a keenly sharpened end and a sample is narrowed to let flow a tunneling current between them and thereby allow observation of the surface of the sample. A strain wave device is disposed on the sample or in the vicinity of the sample to detect strain waves generated within the sample. By modulating the value of the above described tunneling current, strain waves are generated within the sample. The strain waves are detected by the above described strain wave detecting device. On the basis of the amplitude information and phase information of detected strain waves, physical information regarding the inside of the sample is obtained.

Abstract: The inspection head component of a manipulator employed in the inspection of the interior surface of a nuclear reactor vessel is aligned to an optimum orientation when positioned at a local surface to be inspected. This alignment is carried out by generating ranging information with respect to the local surface using ranging ultrasonic transducers positioned upon the inspection head. The propagation interval of the acoustic signal emitted by these ranging transducers is timed and quantified to develop orientation error signals. Such development is carried out in conjunction with known values for the local surface being inspected and in conjunction with a sequence of data collection at the position. The inspection head is pivotally mounted upon the manipulator so as to be movable about at least two axes by inspection head positioning assemblies which may be provided, for example, as stepper-motors and associated translational movement components.

Abstract: An apparatus and method for inspecting multilayer articles. An article to be inspected is clamped in a liquid filled tank between a pair of focused transducers. An ultrasonic pulse is introduced to a cross section of the article from each transducer sequentially. Reflections from the surfaces and interfaces within the article are received by each transducer and transmitted to a computer for analysis. The thicknesses of the innermost layers of the article are determined by calculating the mean of the measurements from each transducer for each inner layer.

Abstract: A device and method for guided testing of an object, and in particular, an internal structural component in an object, using non-destructive ultrasonic techniques is provided. A housing containing at least one ultrasonic transducer probe is adapted to be placed directly on the surface of the object to be tested. Eddy current probes are provided in the housing to guide the ultrasonic probe such that the ultrasonic energy will be directed at the appropriate internal structural design component of the object to be inspected. A microcomputer is then used to record the data obtained using ultrasonic signals and the position on the object using the information designed from the eddy current probes.

Abstract: A multiple arm caliper system for operation of a multiple arm caliper tool is set forth. It incorporates an elongate tool body having a motor means therein. The motor means operates a coupling rod connected to a resilient spring loading a piston within a cylinder. Within the cylinder, and extending through a transverse head defining the cylinder, individual push rods for each caliper arm extend. The push rods are forced from the chamber by fluid pressure within the chamber. Each push rod connects through suitable pivot points to an independent bell crank which is pivotally mounted to rotate each arm. Fluid pressure within the chamber is provided by the motor operating through a push rod which couples through a coil spring in the preferred embodiment to the chamber.

Abstract: In a system for irradiating an ultrasonic beam and imaging the insides of plate-shaped and layer-shaped samples, by using the difference between the sound velocities of a liquid medium and a sample from an ultrasonic transducer to the surface of the sample, the focusing condition is arithmetically operated from the distance between the transducer and the imaging surface which is obtained from the surface echo, and a focal point is set to an arbitrary surface in the sample, thereby correcting a phenomenon such that the focal point of the ultrasonic beam focused into the sample non-linearly moves. Thus, even if the sample is distorted, curved, or inclined, the surface can be imaged at a high resolution and a finer imaging picture can be obtained.

Abstract: An immersion base ultrasonic inspection system for interrogating the bore and near bore material of turbine and generator rotors by passing ultrasonic search units through the rotor bore. This system utilizes variable focus array inspection transducers in a shear mode inspection of the near bore material. The system includes a positioning assembly for a transducer which includes carriage means for supporting the transducer and a first positioning means for tilting one end of the carriage means in a radial axial plane whereby the transducer may be positioned at an angle to a longitudinal axis of the system. A second positioning means is provided for circumferentially rotating the transducer to a known and repeatable angular position. Position resolver means are coupled to the first and second positioning means.

Abstract: An ultrasonic microscope includes a sample rod for supporting a sample and an acoustic lens positioned to face the sample. The lens is moved in two directions in a plane perpendicular to each other to scan the sample. During the scanning operation, the lens is also moved in a vertical direction so that the distance between the sample and acoustic lens is changed, by a piezoelectric actuator for supporting the lens.

Abstract: A transducer is pivoted by a linear motor having an electrical coil as the reciprocally moving member. The coil is in a plane orthogonal to the lines of magnetic flux between opposed permanent magnets of opposite polarity affixed to the probe case, providing efficiency. A mechanical linkage between the linear motor electrical coil moving member and the transducer which is forced in pivoting motion transmits only axial force, and not torque, by employing a ball and socket joint at one end of a crankshaft. Electrical connections to the electrical coil are facilitated through springs which additionally mechanically bias the reciprocal movement of the coil. Electrical connections to the pivoting transducer are facilitated through a helical coil wrapping the pivot shaft. These electrical connections accomodate mechanical motions within the probe. A bellows-fold cylindrical air bladder is positioned within the fluid chamber of the probe to allow for thermally-induced changes in fluid volume.

Abstract: Method and apparatus for detecting cracks in a shaft by means of an ultrasound pulse echo method. A test hand having an ancillary wedge is coupled to the end face of the shaft for conducting nondestructive testing of the shaft. The test head emits ultrasound pulses of a determined frequency and is moved by means of a mechanical device in front of the end face. The method makes possible reliable and reproducible detection of cracks present at the circumference of long shafts. The test head delivers sound pulses in the range of 4 to 8 MHz and is placed by means of the device at a radial distance from the shaft end face's central axis. The test head is moved in the course of the measurements in three degrees of freedom; along a radius of the shaft, along a circle of the shaft and about the axis of the test head holder. The method and apparatus are employed for testing long turbine shafts in the assembled condition from the end face on the generator side of the shaft.

Abstract: An apparatus for locating the geometrical center of symmetrically shaped bore (3) in a material (2) includes a detector (4) distinguishably responsive to a property of the material (2), bore traversing means (6, 9, 10, 11) for moving the detector (4) adjacent the material (2) and along a predetermined raster scan path, and control means (15, 16, 17) responsive to changes in electrical signal outputs of the detector (4) as the traversing means (6, 9, 10 11) is scanned across the bore (3) in two mutually orthogonal directions. The control means is operative to monitor the coordinates of the interceptions of each of two mutually perpendicular chords across the bore (3) with an edge of the material (2), and to calculate the coordinates of the center of the bore (3) from these. Preferably the apparatus includes an eddy current detector (4) for determining the position of a bore (3) and an ultrasonic detector (5) for inspecting the material (2) around the bore ( 3) for flaws.

Abstract: An ultrasonic scanning system for testing large curved components of fiber/resin matrix composite material, the system ultrasonically testing these components with water jet probes caliper-mounted on the working arm of an industrial robot. The computer reads CAD data appertaining to the component, transfers it to robot-compatible form and delivers it on demand to the robot computer. The computer also reads the data output from the probe and reconciles it with the CAD data to yield as an output a quality map of the component. Instantaneous probe position on the surface of the work piece is computed from data on the starting position of the scanning movement of the probe, and the scanning velocity of the probe.

Abstract: An automated ultrasonic examination system for heat transfer tubes in a boiler makes it possible to perform ultrsonic examination from inside of the heat transfer tubes without necessitating the removal of scale from the outer surfaces of the boiler tubes by polishing and without necessitating access to places where manual measurements are difficult or impossible to make.

Abstract: A real-time ultrasonic pipe inspection system is provided which utilizes computer processing methods in real-time to create a user-friendly interactive environment achieving ease of operation as well as a combination of consistency, thoroughness and speed in flaw and thickness detection. Two computers are utilized in a distributed processor configuration wherein one of the computers is dedicated to user input/output, while the second controls real-time processing of ultrasonic data with the two computers being connected via a communications highway. Simultaneous dual level sensitivity inspection of a plurality of separate probed areas is possible. Data input is provided via a touch sensitive CRT, while pipe status can be indicated with automatic color-coding, graphic presentation on a system CRT or hard copy. The system is provided with ultrasonic wheel probes comprising rotably mounted transducer block and yoke assemblies for rapid adjustment of helical scan angle for different sized pipe.

Abstract: A contact ultrasonic transducer head assembly. A stationary housing is adapted to be fitted to a remotely operated manipulator. A movable assembly slidably received by the stationary housing has a plurality of independently suspended ultrasonic transducers mounted thereon. A position encoder mounted in the movable assembly monitors movement within the stationary housing. A limit switch is used to electrically disable the remotely operated manipulator when the movable assembly slides a predetermined distance into the stationary housing to prevent damage to the transducers or the surface being inspected.

Abstract: An apparatus for the inspection of nuclear reactor fuel rods combined in fuel rod clusters with spaces therebetween in a fuel assembly includes test probes each being disposed at a different respective level along the fuel assembly. Fingers are each part of a respective one of the test probes. Ultrasonic test heads are each disposed on a respective one of the fingers. The test heads are inserted into the spaces between the fuel rods, and the insertion position of each of the test probes is corrected independently of the insertion position of the others of the test probes, before insertion of the test probes.

Abstract: An ultrasonic transducer probe is provided which exhibits an angular design, having a body section containing a drive motor and a transducer section. The axes of the two sections are oriented obliquely with respect to each other such that the motor section may be grasped in the manner of a writing instrument while the transducer section is pressed against a patient. In a preferred embodiment, the two sections are coupled together by a flexible bellows and two crystals are mounted on a shaft in the transducer section, one for sector scan imaging and the other for Doppler flow measurement.

Abstract: A mechanical in-line sector scanner is provided in which the ultrasonic transducer pivots about an axis. The transducer is oscillated through an arc about the axis by reciprocating pins, which alternately push the transducer in opposite directions of scanning. The pins are reciprocated by a continuously turning cam having a cam surface obliquely oriented with respect to the longitudinal axis of the pins.

Abstract: A supersonic flaw detecting system has a probe adapted to emit a supersonic wave towards an object to be inspected, a scanning device for causing a relative movement between the probe and the object in two orthogonal directions, a pulser-receiver adapted to supply pulses to the probe and receive the supersonic wave from the object and produce an electric signal indicative thereof, a signal processing device for converting the electric signal from the pulser-receiver into an image data signal for a C-scope display, an oscilloscope for conducting an A-scope display of the electric signal from the pulser-receiver, and a monitor T.V. having a screen for conducting the C-scope display of the image data signal from the signal processing device.

Abstract: A mechanical delivery system for remotely positioning an ultrasonic sensor in mating engagement with a component to be inspected has an elongated support which can be manipulated at a first end from a remote location. A second end has an arm for carrying the sensor. A pin connects the arm to a housing which has an opening therein. A pinion gear is connected to the arm and a mating rack gear is connected to an actuator rod for moving the arm between a first position parallel to and within the housing and a second position wherein that portion of the arm carrying the sensor extends laterally of the housing through the housing's opening. The sensor is mounted on the arm such that it is permitted limited rotation about an axis perpendicular to the arm and limited rocking about a point on that axis thereby enabling the sensor to engage the component as a result of manipulation of the first end of the elongated support despite mispositioning of the second end of the support relative to the component.

Abstract: A device for inspecting a rail 2 of a railway track comprises a truck 1 running on the rail and carried by a railway vehicle. The truck carries at least one ultrasonic emitter and/or receiver probe 7, 8 in contact with the upper surface of the rail. At least one probe 8 is displaceable on a slide 6 while another probe 7 is fixed to the truck 1. The device comprises a jack 9 for displacing the probe 8 as a function of variations of the energy received by the receiver probe to compensate for fluctuations in the height of the rail.

Abstract: A method, and an apparatus for carrying out the method, for displacing a weld scanner in and out of a horizontal reactor vessel nozzle submerged in a water pool characterized by buoyancy chambers into which water and air may be introduced by remote control to move the scanner and an associated telescopic boom, column and spider into position relative to the reactor vessel.

Abstract: Apparatus for continuously orienting an ultrasonic transducer so that the emitted ultrasonic waves remain at a normal angle of incidence to the opposing surface of an object while the transducer is being moved laterally across the surface in order to inspect the subsurface composition of the object. The sensor casing which contains the ultrasonic transducer pivots about one end of a tubular support arm, while the other end of the support arm pivots about a gearbox casing. A drive shaft passes through the support arm and has a miter gear on each end. One miter gear is engaged with a miter gear attached to the gearbox casing, and the other is engaged with a miter gear attached to the sensor casing so that the rotation of the drive shaft causes the simultaneous rotation of the support arm about the gearbox casing and, in the opposite direction, the rotation of the sensor casing about the support arm. The gearbox casing is attached to a carriage and has the freedom to roll relative to it.

Abstract: In an ultrasonic microscope, if a plane to be observed of a sample is not parallel with a scanned plane formed by an ultrasonic wave beam, an interference with a reflected wave will be produced and no clear picture image will be obtained. Therefore, it is indispensable to adjust the inclination of the sample stand as an initial adjustment before the observation.

Abstract: The invention relates to a surface testing apparatus in which sensors are driven with a reciprocating movement above the surface being tested. To minimize the forces which are required for the driving of the sensors, a vibratory system is provided for this movement, which is driven by an exciter system at or close to its natural frequency.

Abstract: A heat-sterilizable ultrasonic surgical scanner includes an ultrasonic transducer and a permanent magnet motor for moving the transducer along an arcuate path. The scanner further includes a housing for the ultrasonic transducer and the motor. The housing includes an acoustically transparent window for transmitting ultrasonic energy from and into the housing. A resilient diaphragm permits expension and contraction of a coupling fluid with which the housing is filled without causing fluid loss from the housing due to leakage. The resilient diaphragm is mounted at a location remote from the acoustically transparent window.

Abstract: A position sensing apparatus includes an ultrasonic wave transmit-receive element for transmitting and receiving ultrasonic waves to and from an object whose position is to be sensed and a manipulator for changing the relative positions between the object and the ultrasonic wave transmit-receive element, and a signal processor utilizing changes in the reflected signal intensity in the vicinity of the center of the object to be measured, thereby sensing the position of the object.

Abstract: In the ultrasonic testing of a casting for defects an ultrasonic probe is mounted in a tank of water and scans across a surface of the casting which faces downwards just below the surface of the water. A pantograph linkage interconnects the probe with a pointer that is movable by an operator over a facsimile of the surface scanned by the probe. The interconnection is such that each position of the probe is represented by a corresponding position of the pointer and as the pointer is moved over the facsimile of the surface the probe scans the surface of the casting. The water ensures that there is good acoustic coupling between the probe and casting and the pantograph linkage reduces the skill and concentration required by the operator. Conveniently, only anomalous signals arising from defects are passed on from the probe to the operator.

Abstract: An ultrasonic scanning apparatus includes a rotor, first and second electromagnetic stators, and an ultrasonic transducer mounted on the rotor. Each electromagnetic stator has two curved pole faces arranged opposite pole faces on the rotor. The electromagnetic stators are arranged on opposite sides of the axis of rotation of the rotor. The stator pole faces are tapered such that on rotation of the rotor in one direction, the gaps between the rotor and a first stator decrease while the gaps between the rotor and the other stator increase. On rotation of the rotor in the opposite direction, the gaps between the rotor and the first stator increase and the gaps between the rotor and the second stator decrease. Means are provided for alternately energizing the first and second electromagnetic stators to cause the rotor to oscillate about the axis of rotation.

Abstract: A tool (100) for scanning the inner surface (110) of a pipe (106), comprising a scanning section (112) interacting with a centering section (114). The scanning section includes an axle member (128) having strut members (130) rigidly connected thereto and projecting diametrically outwardly for urging inspection probe sleds (126) against the pipe surface. The centering section (114) includes a slide cylinder (124) coaxially disposed about the axle member (128), and having rigidly connected actuating members (120) projecting diametrically outward for contacting the pipe inner wall with sufficient force to center and support the tool within the pipe. Locking means (146) are provided within the actuating member (120) for selectively engaging the axle member (128) to lock the longitudinal position of the strut member (130) relative to the actuating member (120).

Abstract: A heat-sterilizable ultrasonic surgical scanner includes an ultrasonic transducer and a permanent magnet motor for moving the transducer along an arcuate path. The scanner further includes a housing for the ultrasonic transducer and the motor. The housing includes an acoustically transparent window for transmitting ultrasonic energy from and into the housing. A resilient diaphragm permits expansion and contraction of a coupling fluid with which the housing is filled without causing fluid loss from the housing due to leakage. The resilient diaphragm is mounted at a location remote from the acoustically transparent window.

Abstract: An acoustic microscope comprising an acoustic transducer which performs both generation and detection of acoustic wave beams, and a sample holding member which opposes to an acoustic wave transmitting and receiving surface of the transducer, to hold an object sample through an acoustic wave propagating medium and to offer behind the sample a layer of an acoustic impedance unequal to that of the sample, so that the sample holding member is moved in parallel, thereby to detect acoustic waves reflected from front and rear surfaces of the sample and acoustic waves reflected from a surface of the sample holding member without reaching the sample and to measure amplitudes and returning periods of time of the reflected acoustic waves, so as to measure the velocity of sound through the sample of unknown thickness, the acoustic impedance of the sample, etc. from the measured values.