Abstract: A gauge for measuring an out-of-plane surface displacement profile around a cold-worked fastener hole in relation to the distribution of residual compressive stresses around the hole and related fatigue life. The gauge has a deformable strain sensor positionable to be deformed in accord with the out-of-plane surface of the structural material circumferentially surrounding the cold-worked hole. A measurement reporting readout device is in communication with the strain sensor and relates three-dimensional surface-profile measurement data in accord with strain sensor deformation to determine or verify the cold expansion magnitude, uniformity and consequent fatigue life through three-dimensional elastoplastic finite element comparative analyses and/or experimental measurements for a hole in any material of given thickness.

Abstract: A strain gage includes, in stacked order, a backing film (1), a measuring resistor grid (2), and a cover (16) including a first layer (6) of an insulating material and a second layer (7) of a metallic material. At least the metallic second layer (7) of the cover is a metallic foil having a size or extension in the plane of the cover that is smaller than or equal to the size or extension of the backing film (1). The strain gage is simple to manufacture in a continuous strip or large sheet process, and is relatively insensitive to the effects of moisture or changes in humidity.

Abstract: A linear position transducer (10) including a housing (12), a threaded stud (56) fixedly secured within the housing, a rotatable drum (26) thread-mounted on the threaded stud, a string (18) secured to the drum and extending from the housing, a torsion spring (80) attached to the drum providing retraction torque to the drum, a cantilever beam (28) having one end fixed to the housing and the other end biased against the drum, and a strain gauge (48) for measuring deflection-induced strain in the cantilever beam. The drum moves axially along the threaded stud as it rotates in response to linear movement of the string. As the drum moves axially, it deflects the cantilever beam, which deflection is detected by the strain gauge. The strain is proportional to the linear movement of the free end of the string.

Abstract: An arrangement for measuring distortion in cylinders. A sensor projects straight out of the end of a motion-transmitting arm. The arm can be both translated and rotated. The sensor accommodates a probe that probes the geometry of the surface of the cylinder. The sensor has a distortion-measuring structure accommodated in the head of a surface-geometry probe and a check for axially secured and undeflected tensioning of the probe. The probe is an elongated geometry-probing pin. The structure is securely tensioned remote from the chuck in the vicinity of a structure-attachment section in the head. The structure includes at least one zone of attenuation between the chuck and the structure-attachment section and has a resilient section and a strain gauge.

Abstract: A magazine has a plurality of storage ports 400 each of which retains a stylus module 314 for use in measuring workpiece dimensions on a coordinate measuring machine. Each storage port 400 is configured as a pair of jaws provided by docking inserts 414. A permanent magnet 418 is mounted on each docking insert 414. The lower casing of the stylus module 314 is urged against the inwardly facing edges 416 of the docking inserts 414 by the magnetic attraction force due the magnets 418. The stylus module 314 is engaged with a retaining module (on the quill of the machine) by moving the retaining module in a downward sense to engage the stylus module 314; further downward movement disengages the stylus module 314 from the storage port 400, thus enabling engagement of such a stylus module and removal of the module from the storage port in a single continuous movement.

Abstract: A touch trigger probe for machine tools or coordinate measuring machines has three strain gauges SG1-3 which react to deflection of a stylus of the probe, causing a trigger signal to be generated in signal processing circuitry SP. To reduce power consumption, and thus to reduce thermal growth of the probe, the strain gauges are fed by constant current sources CS1-3. The sources CS1-3 are servo controlled from a reference resistance R.sub.ref and constant current source CS4, by an amplifier A4.

Abstract: A prefabricated, easily installable strain gage assembly (10) is provided which includes an elongated synthetic resin substrate (12) having adhesive (16) applied to the majority of one surface thereof while leaving a handling tab portion (18) adjacent one end of the substrate (12). A strain gage unit (28) is secured to the adhesive-bearing surface of substrate (12). A strippable protective film (56) is placed in covering, protective relationship to the strain gage (28) and the adhesive surface of substrate (12). Preferably, the substrate (12), adhesive (16) and film (56) are substantially transparent, and the substrate (12) is provided with perpendicular alignment marks (55, 55a) which are strategically located relative to the strain gage unit (28).

Abstract: A supporting device comprising a first member which supports a springy means for resiliently supporting a second member. The supporting device comprises a detection means for detecting displacement of the springy means with respect to the first member in accordance with the movement of the second member and a biasing means which applies a force to the springy means from the same direction as or from a direction opposite to that of the displacement for changing the elasticity of the springy means in accordance with the movement of the second member.

Abstract: A displacement-measuring apparatus including a cylindrical housing, a static-pressure bearing located within the housing, a probe shaft supported by the bearing so that the bearing is supported in non-contact fashion and is movable in the axial direction, and a stylus connected to the end of the probe shaft so as to apply pressure to an object. Part of the static-pressure bearing includes a hollow cylindrical bush and at least two restriction holes formed in the bush and equidistantly spaced along the circumference of the bush. These holes supply air into the gap between the probe shaft and the bush. The static-pressure bearing further includes a first set of grooves formed in the inner surface of the bush that extend along the axis of the bush so that each opposes at least one restriction hole, and a second set of grooves formed in the circumferential surface of the probe shaft that extend along the axis of the probe shaft.

Abstract: The disclosure pertains to a probe head (PH) for use in coordinate measuring machines and having a stylus (10) supported for axial displacement (D1) and angular displacements (D2,D3). A transducer (T1) senses axial forces (F1) on the sensing end (11) of the stylus due to engagement thereof with a workpiece 12. A strain gauge system (16) provided on the stylus senses transverse forces (F2) on the sensing end (11) of the stylus. The forces (F1,F2) are used to determine the orientation of the surface (12A) of the workpiece and a control system is described which responds to those forces to maintain the stylus normal to said surface (12A) during a scanning operation.

Abstract: A sensing device and an analyis process which determines the shape of the periphery of a cross-section of a body as it deforms or is defomed in time. The sensing device is a band attached to the surface of the deformable body along the external peripheral path of the desired geometrical cross-section; the band has sensing devices on it, each of which produces an output proportional to local curvature as the band is deformed. The analysis process integrates the outputs from the sensing devices to calculate the shape of the periphery of a cross-section of the body to which the band is attached.

Abstract: An apparatus is disclosed for determining pressurization in a nuclear fuel rod and the like by measuring the increase in diameter of the fuel rod occasioned by the internal pressurization of the rod, and which includes an elongate receiving member having front and rear ends and an axial opening extending therein. A gauge is positioned in the axial opening and is adapted to coaxially surround the fuel rod and then measure an increase in diameter of a fuel rod caused by a pressure increase within the rod. The gauge is formed from a substantially C-shaped bracket having inner and outer surfaces, spaced distal end portions and a more thin medial portion, and with a strain gauge mounted on both the inner and outer medial surfaces. A microprocessor is connected to the strain gauges so that changes in electrical output from the strain gauges can be measured to determine the increase in diameter of the fuel rod upon pressurization of the fuel rod.

Abstract: The present invention is directed to a probe and method for measuring the radius of curvature of a bend in a section of tubing. The probe includes a member with a pair of guide means, one located at each end of the member. A strain gauge is operatively connected to the member for detecting bending stress exrted on the member as the probe is drawn through and in engagement with the inner surface of a section of tubing having a bend. The method of the present invention includes steps utilizing a probe, like the aforementioned probe, which can be made to detect bends only in a single plane when having a fixed orientation relative the section of tubing to determine the maximum radius of curvature of the bend.

Abstract: The sensor has at least one strain gauge secured to a strip sufficiently flexible to bend without permanent plastic deformation through a small radius. The output is directly proportional to the relative angular orientation of the ends of the strip regardless of the orientation intermediate the ends.

Abstract: Side-by-side inductor coils are wound in a single layer around a thin flat tubular frame. The frame has a closed end portion and is mounted on an insulative base sheet. An elongated thin magnetic core is cantilevered from a insulative connecting rod and normally is positioned inside the frame approximately centered between the two coils. The end portion of the connecting rod remote from the frame is secured to the base sheet. The base sheet can be applied to a specimen to be stress tested and is formed to withstand elongation and compression. Lengthwise sliding of movement of the magnetic core in the coil frame due to stress applied to the specimen indicates the strain of the specimen.

Abstract: Method of precisely positioning a first terminal portion of an elongated tensile rod with respect to a base member coupled to a second terminal portion of the tensile rod which has a threaded portion, involves providing an electrical strain gage measurement device affixed to the tensile rod, a load tube positioned about the rod, having a first terminal portion positioned against the base member, and tightening a nut member over the threaded portion of the rod and against the load tube for producing compression of the tube and tension within the rod until a signal produced by the strain gage measuring device indicates a desired position of a terminal portion of the rod with respect to the base member.

Abstract: Structural components, especially components having complicated configurations, are endurance tested for their creep resistance or strength in a removable massive metal testing block which encloses the component being tested in the manner of a mold. The mold type testing block is made of a high heat resistant metal acting as a susceptor in an induction heating system in which the testing block is surrounded by an induction heating coil. In this system the component being tested can be heated to high, highly constant temperatures which provides a substantial improvement in the creep testing results and reduces the cost of testing.

Abstract: A magnetic amplifier employing a single four-legged ferrite core having orthogonally disposed through holes in the core. Biasing is provided of the magnetic core so as to provide operation in the non-linear parts of the core's hysteresis cycle. A first coil on the ferromagnetic core has an AC excitation signal applied thereto and a second coil on the core is wound orthogonally to the first coil and is adapted to have an output signal derived therefrom. A control or input current in a third coil is used to unbalance the magnetic bridge formed by the four legs, so as to produce a mutual inductance different from zero between the first and second coil. The biasing may be provided by a fourth coil or by permanent magnet means.

Abstract: Disclosed is an apparatus for measuring the deviation from a straight line of an elongated passage having opposing sides. The apparatus comprises a member sufficiently bendable and sufficiently large that it can pass through the passage in contact with both of the sides of the passage. Included is a means for measuring the amount that the member bends as it passes through the passage, means for moving the member through the passage between its opposing sides, and means to indicate, collect, and analyze the resultant electrical signals. The apparatus is most useful in measuring and locating deformations in the tubes of the steam generators of nuclear reactors.

Abstract: A precision electromechanical measuring device utilizes a strain gauge or pressure transducer to sense changes of position in a workpiece contacting finger. The finger is pivotable about a relatively stiff pivot to different positions, enabling the instrument's use as a center finder for circular bores and pins or for verifying the flatness and perpendicularity of a disc or plate to the axis of rotation of a spindle. A housing of the device supports a rotatable shank extending from one end for engagement in a chuck, mandrel or collet associated with a spindle of a machine, and also supports pivotal apparatus including the finger extending out the other end of the housing. Brushes conduct a variable signal from the strain gauge in the housing to the exterior, where the signal is fed to an ammeter.

Abstract: A measuring cassette for checking magnetic head insertion distance and tape guide height in a magnetic tape cassette machine. A spring tongue in the cassette has at least one strain gauge on its surface to measure tongue bending, and is arranged to be deflected by insertion of the head into the cassette so as to sense the head surface or tape guide alignment with respect to the cassette.

Abstract: Disclosed is a dendrometer for use on soft stemmed herbaceous plants. The dendrometer uses elongated jaws to engage the plant stem securely but without appreciable distortion or collapse of the stem. A transducer made of flexible, noncorrodible and temperature stable material spans between the jaws which engage the plant stem. Strain gauges are attached at appropriate locations on a transducer member and are connected to a voltage source and voltmeter to monitor changes in plant stem size. A microprocessor can be used to integrate the plant stem size information with other relevant environmental parameters and the data can be recorded on magnetic tape or used in other data processing equipment.

Abstract: A slitter knife holder has a rod for supporting a slitter knife. Strain gauges are attached to the rod. There is provided a conversion circuit for converting changes in electric resistance of the strain gauges due to the deflection of the rod caused by the pressure of contact of the upper blade with the lower blade of the slitter knife into a signal indicative of the pressure of contact of the upper blade with the lower blade. The signal from the conversion circuit may be applied to a contact pressure monitor for indicating the signal directly to an operator or to an automatic contact-pressure control system.

Abstract: A method for quasi-hermetically covering physical structures on structure supports is described, which is low in its back-action on the structures to be protected and is especially suited for covering strain guage strips on cantilever beam measuring springs. In the method films made of a vacuum-tight, inorganic material are used as the covering substance, these films intimately joining both the structure to be protected and the surface zone of the support in the immediate vicinity of the structure. The use of films of monocrystalline structure, for instance mica films, is especially recommended, and it also is recommended to decrease the thickness of these films, once they are deposited, by suitable procedures such as etching or cleaving off crystal layers.

Abstract: Wheel alignment testing apparatus is shown for use with the wheels of a motor vehicle. This apparatus is adapted for use with the racks of an alignment machine. A remote monitoring console would be provided with gauges for recording the reading of caster, camber, toe and turning radius angles of both front wheels of the vehicle. The apparatus includes two units, one unit for each front wheel. Each unit has a stationary base and a wheel-supporting platform or turntable with front and rear rails for centering the center of the wheel on the vertical turning axis of the turntable. A cross-bar transducer is supported from the turntable, and it is provided with electrical strain gauges at both the front and rear of the wheel for sensing either a positive or negative caster angle, as well as at both the left and right sides of the wheel for sensing either a positive or negative camber angle.

Abstract: A position sensor comprising a movable member functionally connected with an operative device and moving in response to a positional displacement of the operative device, a displacement-pulse phase conversion unit including a magnetically soft amorphous metal member undergoing stress variations produced by the displacement of the movable member and an electrical coil wound on the magnetically soft amorphous metal member. A pulse voltage is applied to one end of the electrical coil, the other end of which is connected in series with a resistor. A voltage across the resistor is detected, and a time lag of the resistor voltage with respect to the pulse voltage, representing a measure of displacement, is provided in the form of an analog voltage or a digital code.

Abstract: An apparatus for measuring the evenness of a substructure, e.g. a road surface, is fitted to a vehicle. The free ends of a number of pivotable measuring arms, uniformly spaced side by side over the entire vehicle width, engage the substructure resiliently during measurement. Each measuring arm is pivotably mounted in a measuring housing which has a plate spring coacting with each arm. On pivotation of the arm relative to said housing, as a result of unevenness in the substructure, the plate spring executes a corresponding deflection, sensed by strain gauges attached to said spring and giving output signals, proportional to the deflection, to an electronic unit wherein the signals are converted to output data representing the surface evenness of the substructure.

Abstract: A position sensing device having a plurality of angular position sensing probes movably mounted within a support member for simultaneously engaging a surface when the support member is moved into proximity with the surface. Transducers associated with each of the probes sense movement thereof and provide electrical output signals indicative of the positions of the probes relative to the support member. The relative separation between the support member and the surface is determined through the calibrated movement of at least one of the probes as indicated through the signals of the associated transducer. Lateral position sensing is provided through a central probe mounted in cantilevered fashion to the support member, with two transducers positioned in orthogonal planes on the lateral position sensing probe which provide an indication in which direction the sensing device must be moved in order to eliminate sideway forces acting on the lateral position sensing probe.

Abstract: An extensometer for detecting traumatized ligaments where the elongation of the ligament is either abnormally large or abnormally small compared to the elongation measured on a healthy ligament for an angle of flexion of the knee. The extensometer includes at least one flexible member having a strain gauge secured thereto to measure deflexion of the flexible member from its normal configuration. The flexible member has a free end and is secured at its opposed end to a support base. A clamping member is provided to retain the free end of the flexible member on a ligament while maintaining the support base substantially stationary with respect to the ligament whereby elongation of the ligament is detected by the deformation of the flexible member from its initial configuration.

Abstract: A cantilevered leaf spring with strain gages on the top and bottom surfaces and a phonograph needle disposed on the free end is disposed in a split tubular base which fits over a long tube to measure the depth of scratches in the outer surface of a long tube.

Abstract: A system for inspecting the relatively long, thin-walled, small-bore tubes of a heat exchanger provided with support plates for holding the tubes in predetermined positions, comprising a composite scanner having a plurality of flexure springs contacting the interior surface of a tube for detecting and profiling tube abnormalities as the scanner traverses the tube and an eddy current sensor for generating a unique signal as the scanner passes a contiguous support plate to assist in the accurate location of tube abnormalities.

Abstract: Hole alignment probes utilizing strain gages spaced 90.degree. apart to indicate the extent and direction of misalignment of holes disposed in substantial alignment.

Abstract: A device for converting the intensity of a magnetic or an electromagnetic field into an electric signal wherein movable elements are made as ferromagnetic plates rigidly fixed in supports so that their free ends overlap each other. Mounted on the deformation section in the immediate vicinity to the place where the ferromagnetic plate is fixed in its support is an element sensing the displacements of the free ends of the plates with respect to each other. The sensing element is made as at least one resistance strain gauge connected to a measuring circuit.

Abstract: A pipeline pig is equipped with a gauging plate which consists of a flexible disc having strain gauges secured thereto so as to be subject to deformation when the disc makes contact with an obstruction or deformation in the pipe wall. The strain gauges are connected in a bridge circuit which goes out of balance when the disc is deformed. The output of the bridge circuit is connected to means for producing an output signal when the disc is bent rapidly but not when it is bent slowly so as not to respond to slow deformation due to build-up of debris in front of the pig.

Abstract: The digital indicator measures surface deviations from a reference measurement point and employs a probe or plunger positionable against a part that is being measured such as a machine part. The device basically comprises, in addition to the probe or plunger, strain gage means, an amplifier for receiving signals from the strain gage means, a digital volt meter, a digital display, and a momentary setting swtich. A preliminary signal from the strain gages at an initial pressure level is coupled via the amplifier to a differential input of the digital volt meter. The momentary switch nulls the meter to zero for the initial reading with deviations of either polarity being subsequently registered and displayed on the digital display.

Abstract: Retractable feeler arms are disposed at uniform angular intervals around a central frame and elastically coupled to the frame for radial withdrawal or outward extension and displacement in a general movement of translation of the device. In the operating position, the tips of the feeler arms are maintained in contact with the cylindrical surface to be measured and differential measurements of the end positions of the feeler arms are taken by means of electrical detectors.

Abstract: The invention contemplates an improved work-contacting probe for use in a measuring machine wherein the relationship between contacted locations on a workpiece are reduced to coordinate digital data. The various described probe embodiments feature means whereby positional errors due to probe flexure upon work contact are substantially reduced, as compared to pre-existing structures.

Abstract: An extensometer capable of simultaneous measurement of axial strain and torsional deflection of a specimen subjected to axial or torsional load. A pair of gauge members define reference plane surfaces, one extending parallel and another extending perpendicular to the test axis. For each reference plane surface there is a follower capable of sensing only the component of relative displacement that lies in the direction normal to the reference plane surface. The sensed values of these followers represent relative axial and torsional displacement of the gauge members. The followers of the embodiment comprise cantilevers extending from ends fixed on one gauge member to ends biased against and freely riding upon the respective reference plane surfaces on the other gauge member. A calibration stand is also shown, comprising a two-part dummy specimen, the parts aligned to define a test axis.

Abstract: An apparatus for measuring the internal corrosion in a pipeline consisting of a pig having a circumferential array of spring-loaded probes for measuring both the average diameter of the pipe and the depth of individual pits. The probes are disposed in pairs with one probe in the form of a stylus having a pointed end for measuring pits, and the other probe having a shoe-shaped end for measuring the average pipe diameter.

Abstract: A new and improved signal-producing pipe caliper adapted to be moved through a section of pipe to detect internal variations in the inside surface of the pipe, and to transmit analog signals corresponding to such variations for suitable recording at a location which is remote from the caliper; such caliper having individual caliper feelers which are separately removable and replaceable without disturbing the electrical signal system, whereby replacement, including size changes of the caliper feelers for accommodating different inside diameters of the pipe being calipered, and/or repair may be accomplished in the field rather than requiring the return of the caliper to the shop.

Abstract: A rolling mill alignment monitor comprising a bar insertable between a roll `pass` and having first and second portions flexibly mounted relatively to one another and carrying strain gauge sensors responsive to any displacement between these portions. By detecting this displacement any misalignment in the pass between the rolls themselves and/or relative to an entry guide box to the pass may be detected.

Abstract: A conical centering feeler is located in axial alignment with the central axis of one of the elements and has its pointed end directed towards the other. If the other element is a nut, for example, the point is directed towards the bore in the nut. If the other element is a bolt, the conical element is hollow and the hollow, wide rim is placed over the bolt. The conical element is held by a flexible deflection tube which is connected to sensors, for example strain gauges, located 90.degree. offset with respect to each other, which, upon bending of the tube, indicating misalignment of the elements, cause feed operation of a cross slide until the bending tube is straight, thus indicating alignment of the two elements. The bending tube holds the conical element in alignment with its point.

Abstract: An electrical strain gauge is mounted to respond to movements between two sections of a structure. The gauge is mounted on a surface that deforms in response to mis-alignment of the sections in a selected plane. The mis-alignment or the deflection is detected electronically utilizing the strain gauge and the degree of deformation, mis-alignment, or flexure is monitored. Upon reaching selected magnitudes in either direction, signals are generated which may be used to control the amount of deflection. When utilized to control the alignment of sections of a traveling irrigation system, the strain gauge is attached to a bar between adjacent sections which bar flexes upon mis-alignment of sections in the horizontal plane. A pair of electrical sensors monitor the deflection but only one is permitted to generate a signal. A switching circuit selects the appropriate signal generator depending on the direction of travel of the equipment.

Abstract: A row-crop harvester adapted to travel along the ground in a transport direction is provided with four crop sensors. One crop sensor is provided to one side and in front of the harvester and normally feels the edge of the crop in front of the harvester and generates an output that controls an automatic steering system which guides the harvester along this edge. Another sensor is provided at the back of the harvester on the other side from the front sensor and serves to feel the edge of the swath just cut. Another sensor in front of the cutter on the harvester detects a gap in the crop and serves to switch the automatic steering system over from the front sensor to the back sensor in case a gap appears in the crop so that the harvester will not swing back and forth to follow minor crop gaps. In addition another sensor is provided on the front of the harvester so that when it arrives at the end of the field the harvester is automatically stopped and can only be moved by manual takeover of the steering.

Abstract: A preassembled strain gauge unit includes a housing having a resilient material therein. At least one strain sensing element is connected to the resilient material. Installation of the strain gauge unit is accomplished by applying adhesive to the strain sensing element and then fastening the housing to a surface with the adhesive between the surface and the strain sensing element. The resilient material is particularly designed to function as a spring during the adhesive curing period to apply a force to the strain sensing element during such adhesive curing period. In addition, the resilient material provides a seal for minimizing contact of moisture and air with the strain sensing element.