Abstract: A structure multi-dimensional loading test system considering real complex boundary conditions considering real complex boundary conditions comprises a main part of machine, a base part, a hydraulic power supply and a control system. The system can simulate the load borne by a structure in a real working environment better and more accurately, realize multi-dimensional loading of the structure with six degrees of freedom in space and provide more real and valuable experimental data for the research on damage of reinforced concrete materials, components and structures under the action of an earthquake, and the research results will help researchers further reveal the damage mechanism of reinforced concrete structures, put forward the corresponding damage criteria and develop the corresponding seismic design methods.

Abstract: A site effect simulator, including a site effect simulator base plate, where counter-force pillars are vertically arranged at diagonals of the site effect simulator base plate, the counter-force walls are connected to counter-force pillars along two sides of the site effect simulator base plate, a plurality of single-layer soil boxes are arranged at the inner side of the site effect simulator base plate, wave-absorbing materials are arranged inside single-layer soil boxes, and sliding panels are arranged at an upper side and a lower side of each single-layer soil box. The present disclosure does not need to rely on other counter-force frames, has the characteristics of flexible use, and can be randomly placed, and the height can be adjusted randomly. With a servo hydraulic actuator with three directions and six degrees of freedom, seismic simulation tests can be realized independently.

Abstract: A device comprises an assembly for attaching to and moving on the production line. The attachment and movement assembly comprises at least two clamps that can be actuated selectively to clamp the production line, the attachment and movement assembly comprising an active mechanism for moving the clamps longitudinally relative to each other. The attachment and movement assembly comprises a tilting mechanism for tilting the clamps relative to each other, between a position in which they are parallel to each other and a position in which they are tilted with respect to each other. The tilting mechanism comprises a flexion bar capable of switching from a straight configuration in the parallel position of the clamps to a curved configuration in the tilted position of the clamps.

Abstract: Embodiments described herein provide an audio device and a method of operating the audio device. The audio device comprises at least one surface, a first surface transducer positioned to excite first modes of oscillation in a first surface of the at least one surface, and a second surface transducer positioned to excite second modes of oscillation in a second surface of the at least one surface, wherein the first modes of oscillation are of a higher frequency than the second modes of oscillation.

Abstract: Embodiments described herein provide an audio device and a method of operating the audio device. The audio device comprises at least one surface, a first surface transducer positioned to excite first modes of oscillation in a first surface of the at least one surface, and a second surface transducer positioned to excite second modes of oscillation in a second surface of the at least one surface, wherein the first modes of oscillation are of a higher frequency than the second modes of oscillation.

Abstract: An apparatus and method for inducing multiaxial vibrations to simulate an environment for transporting a stack of products is provided. A lower platform is provided for inducing uniaxial vibrations. A link is connected to the lower platform by a lower end of the link. The upper end of the link has a universal joint, through which the link is connected to an upper platform. The upper platform has a top surface, on which the stack of products can be placed. In operations, the uniaxial vibrations of the lower platform are transferred to the upper platform through the link and the universal joint, to induce pivotal movement of the upper platform with respect to the shaft of the link. As a result, multiaxial vibrations can be induced to the stack of products placed on the top surface of the upper platform.

Abstract: An apparatus and method for inducing multiaxial vibrations to simulate an environment for transporting a stack of products is provided. A lower platform is provided for inducing uniaxial vibrations. A link is connected to the lower platform by a lower end of the link. The upper end of the link has a universal joint, through which the link is connected to an upper platform. The upper platform has a top surface, on which the stack of products can be placed. In operations, the uniaxial vibrations of the lower platform are transferred to the upper platform through the link and the universal joint, to induce pivotal movement of the upper platform with respect to the shaft of the link. As a result, multiaxial vibrations can be induced to the stack of products placed on the top surface of the upper platform.

Abstract: A vibration exciter with load compensation for the dynamic excitation of test specimens includes a base, an actuator, an armature which can be moved by the actuator in an excitation direction relative to the base and guided by a linear guiding element parallel to the excitation direction, and a pneumatic load compensator which compensates for the gravity force of at least the armature and the test specimen being excited. A high-quality low-perturbation exciter signal is generated by minimizing friction and other nonlinearities occurring during the load compensation. The linear guiding element of the vibration exciter with load compensation includes an air bearing, and the load compensator includes the linear guiding element.

Abstract: A vibration isolation apparatus includes a support unit that elastically supports an object to a mounting surface, a measurement sensor that measures a displacement of the object relative to the mounting surface, a drive unit that drives the object, and a storage unit. The storage unit stores data indicating a relationship between the displacement of the object and information that indicates a non-linear force produced by an elastic element including a support unit and that corresponds to the displacement. The drive unit drives the object in accordance with the displacement of the object and the data.

Abstract: Resonance test machine for vibration strength testing of a test body which is clamped between a cross member and a vibration head. The vibration head, test body and cross member are part of a second sub-oscillatory system which is vibratable in an axis x, in which the test body and a resonator containing the vibration head, a vibration spring and a vibration body are arranged successively in series along the x axis. A first sub-oscillatory system, which is also vibratable in axis x, is present in series to the second sub-oscillatory system and the resonator, wherein the first sub-oscillatory system contains the vibration body, spring elements, a seismic mass and electromagnetic vibration exciters.

Abstract: A control method for controlling a hydraulic actuator to impart oscillatory excitation to a load, the actuator comprising at least one hydraulic chamber and a movable member capable of moving in said chamber between two extreme positions under the action of a liquid under pressure, wherein the method comprises the steps consisting in: determining an operating point for said actuator, which operating point corresponds to a rest position of said movable member; applying a hydraulic command to bring said movable member into correspondence with said rest position; and applying a hydraulic command to cause said movable member to perform reciprocating movement about said rest position, said reciprocating movement being adapted to apply a desired excitation to said load; the rest position of said movable member being selected to be significantly off-center relative to said extreme positions.

Abstract: A multiple chamber test system is provided. The multiple chamber test system includes a plurality of test chambers that each include a vibration table. In addition, each of the test chambers is provided with thermally controlled air from a common source. An output plenum for providing thermally controlled air to the test chambers may include a flow control device, to provide the same or similar thermal conditions in each of the test chambers. Where pneumatic actuators are used to impart movement to the vibration tables, the exhaust air from the actuators can be prevented from mixing with the thermally controlled chamber air.

Abstract: An impact testing device is provided. The impact testing device comprises a plate and an impact generating module. The plate has a first surface for loading a test object. The impact generating module is fastened to the plate to apply an impact to the plate and actuate the plate along the first direction, the second direction and the third direction independently. Thereby, the impact testing device of this invention is adapted to apply the impact to the test object along any direction under control.

Abstract: A multiple chamber test system is provided. The multiple chamber test system includes a plurality of test chambers that each include a vibration table. In addition, each of the test chambers is provided with thermally controlled air from a common source. An output plenum for providing thermally controlled air to the test chambers may include a flow control device, to provide the same or similar thermal conditions in each of the test chambers. Where pneumatic actuators are used to impart movement to the vibration tables, the exhaust air from the actuators can be prevented from mixing with the thermally controlled chamber air.

Abstract: Briefly, the invention comprises a vibrator with an on-demand start-up system, that inhibits fouling the atmosphere, with one embodiment of the invention including an integral non-fouling start-up system wherein at least one of the bearing surfaces contains a surface adhered lubricant so as to provide an on-demand static start-up system and in another embodiment the on-demand start-up system is a dynamic system that can unbalance the differential forces on the piston therein to ensure that the vibrator will begin vibrating “on-demand”. Thus, two types of start-up systems are available one an on-demand static start-up system and the other an on-demand dynamic start-up system with either of the systems can be used alone or if desired in combination to provide redundant start-up systems.

Abstract: A linear vibrator having an internal cylindrical bearing surface forming a chamber therein and a fluid inlet to direct a fluid into the chamber with a one piece piston slideable located therein with the piston simultaneously rotatable and axially displaceable therein with the piston including a static port to bias the piston and thereby induce piston oscillation when fluid is introduced into the vibrator.

Abstract: The invention relates to a vibration isolation system, comprising at least one fluid bearing having a first control device in order to control the fluid pressure and having at least one actuator in order to compensate for position changes of the load to be isolated, which actuator is controlled by at least one second control device, wherein the input of one control device is connected to the output of the other control device.

Abstract: A method of operating a vibratory testing apparatus is disclosed including providing a table frame with at least one vibrator attached thereto and attaching the at least one vibrator to a solenoid valve, wherein an input of the solenoid valve is connected to a pneumatic air supply and an output of the valve is connected to the vibrator. The solenoid valve is connected to a controller and a first control signal is sent from the controller to the solenoid valve for opening the valve and allowing a first burst of air to the vibrator thereby causing the vibrator to vibrate the table frame at a first amplitude. Then a second control signal is sent from the controller to the solenoid valve for opening the valve and allowing a second burst of air to the vibrator thereby causing the vibrator to vibrate the table frame at a second amplitude.

Abstract: In a first embodiment of the present invention a method of monitoring individual vibrators in a pneumatic vibration testing system is disclosed. The method includes providing a pneumatic vibration testing system including at least one vibrator, where each vibrator is connected to a pressurized air system through an output of a valve. Pressurized air is then supplied at a known pressure to an input of the valve. When that air is supplied to the valve the valve releases air in measured bursts to the vibrator and the pressure between the valve and the vibrator is monitored. The pressure between the valve and the vibrator is compared to the known pressure, which indicates if the vibrator is failing or has failed. In preferred embodiments, the testing system includes a plurality of vibrators and an equal plurality of valves, each vibrator is connected to the pressurized air system through a single associated valve.

Abstract: A method of operating a vibratory testing apparatus is disclosed including providing a table frame with at least one vibrator attached thereto and attaching the at least one vibrator to a solenoid valve, wherein an input of the solenoid valve is connected to a pneumatic air supply and an output of the valve is connected to the vibrator. The solenoid valve is connected to a controller and a first control signal is sent from the controller to the solenoid valve for opening the valve and allowing a first burst of air to the vibrator thereby causing the vibrator to vibrate the table frame at a first amplitude. Then a second control signal is sent from the controller to the solenoid valve for opening the valve and allowing a second burst of air to the vibrator thereby causing the vibrator to vibrate the table frame at a second amplitude.

Abstract: In a first embodiment of the present invention a method of monitoring individual vibrators in a pneumatic vibration testing system is disclosed. The method includes providing a pneumatic vibration testing system including at least one vibrator, where each vibrator is connected to a pressurized air system through an output of a valve. Pressurized air is then supplied at a known pressure to an input of the valve. When that air is supplied to the valve the valve releases air in measured bursts to the vibrator and the pressure between the valve and the vibrator is monitored. The pressure between the valve and the vibrator is compared to the known pressure, which indicates if the vibrator is failing or has failed. In preferred embodiments, the testing system includes a plurality of vibrators and an equal plurality of valves, each vibrator is connected to the pressurized air system through a single associated valve.

Abstract: Briefly, the invention comprises a vibrator with an on-demand start-up system, that inhibits fouling the atmosphere, with one embodiment of the invention including an integral non-fouling start-up system wherein at least one of the bearing surfaces contains a surface adhered lubricant so as to provide an on-demand static start-up system and in another embodiment the on-demand start-up system is a dynamic system that can unbalance the differential forces on the piston therein to ensure that the vibrator will begin vibrating “on-demand”. Thus, two types of start-up systems are available one an on-demand static start-up system and the other an on-demand dynamic start-up system with either of the systems can be used alone or if desired in combination to provide redundant start-up systems.

Abstract: A pneumatic vibrator for generating a series of force impulses whose frequency, duration, magnitude and shape can be statically and dynamically programmed by varying mechanical, pneumatic, or hydraulic parameters or a combination thereof.

Abstract: In order to provide a vibration testing apparatus which can have a large diameter without introducing undesirable rigid vibration modes, the vibration testing apparatus 1 comprises a support 2, at least one electromagnetic vibration generator 12 mounted on the support, the mounting comprising an annular body 5 and a head expander 10, the annular body being supported by bearings located around the periphery of the annular body 5.

Abstract: A vibration test machine comprises a stationary outer frame, a shake table in the form of a mass to which vibration energy is transmitted inside the outer frame, a driven preload piston supported by the outer frame and coupled to one side of the shake table, a passive preload piston supported by the outer frame and coupled to the shake table on a side opposite from the driven preload piston, and an external force generator external to the outer frame and coupled to the driven piston for inducing high frequency vibrational energy to the driven piston which, in turn, transmits that vibration energy to the shake table. In one embodiment, a multiple degree of freedom shaker comprises multiple exterior force generators each coupled to a corresponding driven preload piston having a related passive preload piston on a opposite side of the shake table.

Abstract: An ultrasonic sonication device includes a velocity transformer or probe which, when coupled to a vibrating transducer of the piezoelectric or magnetostrictive type, resonates in sympathy with the transducer and either increases or decreases the magnitude of the transducer's vibration. A shallow cup assembly is attached to the distal end of the probe. The cup assembly holds a microtiter tray in a suitable orientation and contains an amount of liquid which provides efficient acoustic coupling between a transverse end face of the probe and the microtiter tray.

Abstract: A method, apparatus, for subjecting a test object to vibrational energy testing is disclosed. The apparatus comprises a rotatable joint such as a hydrostatic ball joint for transmitting energy from a force generator to the test object, and a support structure, coupled to the test object and the rotatable joint, for flexibly restraining the test object from rotating about the center of rotation of the rotatable joint. In one embodiment of the invention, the support structure comprises a support member and at least one suspension device disposed between the support member and a ground datum. In another embodiment, the suspension device applies a suspension force to the support member in a direction substantially perpendicular to a vector from the center of rotation to the suspending force. In this embodiment the suspension devices are subjected primarily to compression and tension forces.

Abstract: A vibrator has (a) a housing including a wall forming a cavity, (b) a sleeve in the cavity, and (c) a piston received in the sleeve for reciprocating movement therein. In the improvement, the cavity has a boundary surface inside the housing and the vibrator includes an impact block interposed between the boundary surface and the sleeve. Such impact block is positionally retained in the cavity by the boundary surface and the sleeve.

Abstract: A hydraulic actuator for vibration testing equipment includes a double-acting piston having a coaxial floating piston assembly coupled to one end of the piston rod. The floating piston assembly has a preload piston pressurized to allow the overall length of the actuator to adjust for small changes in distance between the mating surfaces of the vibration test equipment when the equipment tilts or rotates.

Abstract: A shaker table (10) for testing and quality control of devices attached to the table is shown. The mounting table has pneumatic exciters attached (50) thereto. The exciters (50) are attached to the mounting table (20) with a mounting bolt (128) and spacers (132, 132') that comprise an insulating material to inhibit thermal transfer between the device and the exciters (50) and between the mounting table (20) and the exciters (50). The mounting table (20) provides uniform distribution of forces applied by the pneumatic exciters (50). The forces are evenly distributed in all directions from the impact of the exciters on the mounting table. The mounting table (20) is supported on a foundation (2) by adjustable supports (4). The exciters are supplied with pressurized air from a source (12) through an airline (14).

Abstract: A shaker table (10) for testing and quality control of devices attached to the table is shown. The mounting table has pneumatic exciters attached (50) thereto. The exciters (50) are attached to the mounting table (20) with a mounting bolt (128) and spacers (132, 132') that comprise an insulating material to inhibit thermal transfer between the device and the exciters (50) and between the mounting table (20) and the exciters (50). The mounting table (20) provides uniform distribution of forces applied by the pneumatic exciters (50). The forces are evenly distributed in all directions from the impact of the exciters on the mounting table. The mounting table (20) is supported on a foundation (2) by adjustable supports (4). The exciters are supplied with pressurized air from a source (12) through an airline (14).

Abstract: A vibration test fixture includes a reciprocating slip plate carrying an article subjected to vibration and shock testing. A pair of opposed, spaced apart low oil pressure hydrostatic linear bearings support the slip plate during reciprocating single-axis linear travel on the bearings. The slip plate is mounted to each bearing by a single-axis bearing guide system confining the slip plate to reciprocating longitudinal travel on generally planar, two-dimensional bearing surfaces that support the load of the slip plate. The slip plate is reciprocated by a voice coil-driven hydraulic servo valve and double-acting piston actuator integrated into the vibration table between the bearings that support the slip plate. The voice coil connects directly to a pilot valve in the servo valve assembly.

Abstract: A shaker table comprises upper and lower plates spaced apart by a plurality of spacers that fit between the plates. Each spacer has an upper shaft, which threads into a vibrator opening in the upper plate, and a lower coaxial shaft, which slides into a vibrator opening in the lower plate. The spacer has a threaded internal coaxial opening extending through the spacer. A bolt for securing a vibrator to the bottom of the table engages the internal opening and secures the vibrator and the lower plate to the spacer and upper plate. A mounting bolt for attaching a test product or test fixture to the top of the table threads into the internal opening from the top.

Abstract: A vibration testing apparatus which is minimized in size and capable of being assembled with ease includes a vibrating section (11), a vibration generator (10), and a transmitting section (21) for transmitting vibrations from the vibration generator (10) to the vibrating section. The transmitting section (21) is formed with a pair of opposed parallel pressure-receiving plates (23, 24) that are orthogonal to the direction of vibrations, with the vibrating section (11) interposed between the pressure-receiving plates. The vibrating section (11) is formed with pressure-bearing surfaces (14) in opposed parallel relation to the pair of pressure-receiving plates (23, 24). High pressure fluid is fed into clearances (16), defined between the pressure-receiving plates (23, 24) and the pressure-bearing surfaces (14), to form a static pressure bearing. The pressure-receiving plates (23, 24) are clamped by a connecting member (25) under a load whose value enables the static pressure bearing to function as a spring.

Abstract: A vibration test fixture includes a reciprocating slip plate carrying an article subjected to vibration and shock testing. A pair of opposed, spaced apart low oil pressure hydrostatic linear bearings support the slip plate during reciprocating single-axis linear travel on the bearings. The slip plate is mounted to each bearing by a single-axis bearing guide system confining the slip plate to reciprocating longitudinal travel on generally planar, two-dimensional bearing surfaces that support the load of the slip plate. The slip plate is reciprocated by a voice coil-driven hydraulic servo valve and double-acting piston actuator integrated into the vibration table between the bearings that support the slip plate. The voice coil connects directly to a pilot valve in the servo valve assembly.

Abstract: A shaker table (10) for testing and quality control of devices attached to the table is shown. The mounting table has pneumatic exciters (50) attached thereto. The mounting table (20) provides uniform distribution of forces applied by the pneumatic exciters (50). The forces are evenly distributed in all directions from the impact of the exciters on the mounting table. The mounting table (20) is supported on a foundation (2) by adjustable supports (4). The exciters are supplied with pressurized air from a source (12) through an airline (14).

Abstract: A vibration test fixture includes a reciprocating slip plate carrying an article subjected to vibration and shock testing. A pair of opposed, spaced apart low oil pressure hydrostatic linear bearings support the slip plate during reciprocating single-axis linear travel on the bearings. The slip plate is mounted to each bearing by a single-axis bearing guide system confining the slip plate to reciprocating longitudinal travel on generally planar, two-dimensional bearing surfaces that support the load of the slip plate. The slip plate is reciprocated by a voice coil-driven hydraulic servo valve and double-acting piston actuator integrated into the vibration table between the bearings that support the slip plate. The voice coil connects directly to a pilot valve in the servo valve assembly.

Abstract: A vibration assembly comprising a housing (12) having a central cavity (20) and a pair of side cavities (22, 24) of radially smaller dimension than that of the central cavity, all of which extends axially about an axis (26) from opposed ends of the central cavity. A piston (50) is housed within the cavities (20, 22, 24) and includes a mass (52) disposed within the central cavity (20) and a pair of supports (54, 56) which are disposed within respective ones of the cavity pair (24, 22) and which extend axially from the mass. The supports (54, 56) have radial dimensions which are substantially the same as those of the pair of cavities (22, 24). The mass (52) and the supports have axial dimensions which are substantially less than those respectively of the central cavity means and of the pair of cavities (20, 22, 24) for enabling the piston (50) to move axially within the cavities.

Abstract: A vibroacoustically coupled test system is provided utilizing acoustic technology combined with fluid dynamics to create a multipurpose dynamic environmental simulation system for use in geological, commercial, medical, military and marine testing and evaluation. The system comprises a support structure interconnected with a reactive surface through which acoustic energy is propagated to simulate environmental conditions. The acoustic energy is generated by a vibration transducer assembly and function generator. Isolators may also be used as reactive support structure for base plates having test structure mounted thereon.

Abstract: A vibration slip table for use in a vibration testing apparatus. The table s comprised of at least three composite layers of material; a first metal layer, a second damping layer, and a third layer having a high acoustic velocity relative to the first layer. The different acoustic velocities between the first and third layers cause relative shear displacements between the layers with the second layer damping the displacements between the first and third layers to reduce the table longitudinal vibration modes.

Abstract: The disclosure of the invention is directed to a site survey ground vehicle based apparatus and method for automatically detecting source materials, such as radioactivity, marking the location of the source materials, such as with paint, and mapping the location of the source materials on a site. The apparatus of the invention is also useful for collecting and analyzing samples. The apparatus includes a ground vehicle, detectors mounted at the front of the ground vehicle, and individual detector supports which follow somewhat irregular terrain to allow consistent and accurate detection, and autolocation equipment.

Abstract: A vibration test fixture includes a reciprocating slip table carrying an article subjected to vibration and shock testing. The fixture includes low oil pressure hydrostatic linear bearings supporting the slip plate during single-axis linear travel on the bearings. The slip plate is mounted to each bearing by a single-axis guide system of confining the slip plate to reciprocating longitudinal travel on a general planar, two-dimensional bearing surface which supports the load of the slip plate during its travel. The guide system restrains relative movement of the slip plate laterally and vertically with respect to the bearing surface. A film of lubricating oil is supplied to the bearing surface to lubricate the sliding longitudinal travel of the slip plate on the bearings. The film of lubricating oil is also supplied to the lateral and vertical restraint areas of the bearing.

Abstract: The present invention concerns an apparatus for automatically eliminating a group of articles to be treated of which at least one is missing or defective in this group, this apparatus comprising essentially a detecting cell located above the articles or containers transported by a conveyor, a magazine for storing these containers located near the detecting cell, and pushers arranged vertically under the magazine and under the containers transported by the conveyor.

Abstract: Hydrostatic bearing vibration test apparatus in which the pillow block housing is opertively coupled to the workpiece by an oil film while the carriage blocks are fixed to the workpiece and the bearing shaft, the housing being supported on flexible bolts permitting two degrees of freedom in the bearing appartus.

Abstract: A shaker table (10) includes a table base (12) mounted upon isolating supports (32) and vibrated by vibrators (34, 36). The vibration is conveyed through and damped in a flexure member (16) comprising pairs (26, 28) of honeycomb layers (18, 20, 22, 24) joined and bonded together by sheets (42) utilizing beads of elastomeric adhesive which space the honeycomb layers apart. A segmented top plate (14) is secured to the topmost honeycomb layer and is divided into a plurality of sections or segments (68-82) for separate resonances. In this way, highly damped vibrational resonances of table top plate (14) are obtained.

Abstract: The present invention provides a circuit for obtaining higher accuracy and total system response for complex mechanical impedance loads, such as earthquake simulators, and in particular to compensate for limitations in controlling the actual valve spool displacement and adequately stabilizing and controlling it at high frequencies. The improvement circuit includes a state variable filter to extend the band width of servovalve actuation frequencies by adding a lead compensation signal compensating for servovalve hydraulic responses. The output of the first filter circuit then in turn feeds a summing junction where the spool displacement feedback is provided, and the output of the summing junction or circuit is provided with the output from an additional filter which cleans up the signal by filtering out noise and insures that the phase of stabilizing signals is proper.

Abstract: A load dynamic compensation circuit for a servohydraulic control system for fixtures and specimens being tested operating in various degrees of freedom, for example in an environment to simulate earthquakes to test building specimens, or to provide road profile simulation for rail and automobile vehicles, or wind buffet loads for aircraft. A compensation circuitry compensates for specimen displacement disturbances in the control loop that are a function of the force exerted from the specimen and the acceleration of the test mass.

Abstract: A reaction mass and hydraulic cylinder assembly for a seismic transducer. A hydraulic biasing cylinder (76) is formed between a lower piston rod (32) and a reaction mass (44) and is located below a hydraulic drive cylinder (46). The lower piston rod (32) includes a first portion (36) and a detachable second portion (38-40), the detachable second portion forming an upward facing shoulder (42) which partially defines the hydraulic biasing cylinder (76). The hydraulic drive cylinder (46) is formed by a cylinder sleeve (48) and upper and lower cylinder bushings (50 and 52) having lower and upper ends (54 and 56), respectively, concentrically received within the cylinder sleeve (48) to define the upper and lower ends, respectively, of the hydraulic drive cylinder.

Abstract: Vibration testing apparatus comprises a vibration generator coupled to a horizontal slip plate by means of a driver bar, having limbs which embrace opposite sides of the slip plate. The lower limb of the driver bar is separable from the remainder of the driver bar so as to enable the vibration generator and the remainder of the driver bar to be pivoted away from the slip plate without lateral displacement of the slip plate along its horizontal axis.

Abstract: An acoustic scanning microscope includes a specimen table for supporting a specimen illuminated by an ultrasonic wave. The specimen table is supported in a non-contacting manner under aerostatic pressure or alternatively magnetic repulsion.