Abstract: A wall shear sensor includes a floating element fixedly attached to a base. The floating element has a sensing head opposite the base, a first flexure between the sensing head and the base, and a second flexure between the first flexure and the base. The wall shear sensor further includes at least one strain gauge coupled to the first flexure to measure a first directional component of wall shear stresses applied across a head surface of the sensing head; and at least one strain gauge coupled to the second flexure to measure a second directional component of wall shear stresses applied across the floating element surface of the sensing head, the second component being different from the first component. The wall shear sensors thus measure both magnitude and direction of wall shear. Wall shear measurement systems include at least one wall shear sensor within a sensor housing.

Abstract: The invention relates to a strain-sensitive resistor, comprising a resistance layer arranged on a support element and an electromechanical transducer produced with this resistor. An increase in the electrical measured signal picked off across the resistor is achieved in a simple way by the support element (1) having a recess (7) on its surface (9) which, when the support element (1) is subjected to mechanical stress in at least one area of the surface (9) of the support element (1) in which the resistance layer (4) is positioned, produces a ratio between the two main strain directions (L, T) of the resistance layer (4) which differs in magnitude.

Abstract: In a garment 10, 12 incorporating an electronic device such as a radio 16, a variable of the device, such as volume, is varied by the use of two cords 22, 24, the electrical resistance of each cord decreasing in accordance with an increase in tension applied to the cord; pulling one cord increases the volume of the radio and pulling the other cord decreases the volume. The stronger the pull, the faster the change in volume. The ends of the cords lie outside the garment and carry toggles 26, 28 for easy operation by a gloved hand. Alternatively the ends of the cord outside the garment may be connected to opposite ends of a manual grip 48.

Abstract: A high-performance strain gauge has a high gauge factor and a decreased temperature coefficient of resistance (TCR). The strain gauge has a laminated structure that includes a first layer formed of a positive TCR material and a second layer formed of a negative TCR material.

Abstract: In a garment 10, 12 incorporating an electronic device such as a radio 16, a variable of the device, such as volume, is varied by the use of two cords 22, 24, the electrical resistance of each cord decreasing in accordance with an increase in tension applied to the cord; pulling one cord increases the volume of the radio and pulling the other cord decreases the volume. The stronger the pull, the faster the change in volume. The ends of the cords lie outside the garment and carry toggles 26, 28 for easy operation by a gloved hand. Alternatively the ends of the cord outside the garment may be connected to opposite ends of a manual grip 48.

Abstract: A resistant based thermal probe including a nanometer sized four-leg filament integrated with a piezoresistive AFM type cantilever is created by depositing the filament structure onto the cantilever by a chemical vapor deposition technique where the cantilever is exposed to the flux of precursor gas. An incident electron beam causes a fragmentation of the gas molecules leaving a deposit behind which leads to a conductive deposit shaped as a multi-leg filament structure for thermal measurements of a sample. A deposited four leg filament structure has a mechanical rigidity, high spatial resolution, low thermal conductivity and thermal capacitance, fast response time, and in combination with a four point resistant measurement and lock-in technique, eliminates resistivity for increasing both the temperature sensitivity and the signal-to-noise ratio of the thermal probe.

Abstract: A strain-sensitive resistor including a resistance layer arranged on a support element and an electromechanical transducer produced with this transistor. The support element has a recess in its surface. When the support element is subjected to mechanical stress in at least one area in which the resistance layer is positioned, the recess produces a ratio between the two main strain directions of the resistance layer which differs in magnitude.

Abstract: A rotary position sensor for sensing the position of an attached object. The sensor uses a strain gage to detect the position of the object. The sensor includes a housing and a helical shaped actuator located in the housing. The actuator is attachable to the object. A strain gage is positioned in contact with the actuator. The actuator applies a strain to the strain gage as the actuator is moved. The strain gage generates an electrical signal that is proportional to the position of the object.

Abstract: An acceleration change detection system, which in a preferred embodiment is used as an impact detection system, detects whether a deflection sensor is deflected. The magnitude and/or direction of the impact may be considered. The system may include one or more than one deflection sensor. The invention may have particular use in a system that determines whether to deploy an air bag in a vehicle. The system may employ an open or enclosed chassis. The deflection sensors may deflect against deflection structures, which may be in various shapes. The deflection sensors have an electrical parameter (such as resistance) that changes upon deflection of the deflection sensor. In certain embodiments, the deflection sensor is ordinarily held in place by a movement inhibitor, which may include, for example, a magnetic, spring, clip, or stiff substrate. A large impact may create a force great enough to overcome the magnetic or mechanical force of the movement inhibitor.

Abstract: A linear position sensor for sensing the position of an attached object. The linear position sensor uses a strain gage to detect the position of the object. The sensor includes a housing and a ramp shaped actuator located in the housing. The actuator is attachable to the object. A strain gage is positioned in contact with the actuator. The actuator applies a strain to the strain gage as the actuator is moved. The strain gage generates an electrical signal that is proportional to the position of the object.

Abstract: A rotary position sensor for sensing the position of an attached rotating object. The rotary position sensor uses a strain gage to detect the position of the object. The sensor includes a housing and a rotor located in the housing. The rotor is attachable to the object. A strain gage is positioned in the housing adjacent the rotor. The rotor rotates so as to contact the strain gage and apply a strain to the strain gage. The strain gage generates an electrical signal that is proportional to the position of the object.

Abstract: A deflection sensing system for detecting deflection includes one or more deflection sensors between opposing sets of extensions. When one set of extensions is moved toward an opposing set of extensions, the deflection sensors are deflected. A preferred deflection sensor is a flexible potentiometer, which has a resistance that changes as the flexible potentiometer is deflected A flexible potentiometer includes a variable resistance material on a substrate. In a preferred system, the flexible potentiometer includes a cantilevered section, which is deflected about an extension with respect to the remainder of the flexible potentiometer, or with respect to a portion of the substrate not including the variable resistance material. A flexible potentiometer experiences less stress when in cantilevered form than when stretched between two extensions. In either case, the extensions may be joined to first and second corrugated plates.

Abstract: The object of the present invention is to obtain high-precision semiconductor pressure detecting devices without unevenness in gauge resistance values. When a recrystal silicone film 23 is formed by use of laser, a crystal subgrain boundary 27 generates, and crystal fault is included in (100) direction. A metallic wiring 51 of aluminum or gold is arranged on said crystal subgrain boundary 27 crossing a gauge resistance 3A. The current running through a gauge resistance formed by said recrystal silicone film 23 runs into said metallic wiring 51 at the portion of said crystal subgrain boundary 27. Therefore, the current running through said gauge resistance is unlikely to be affected by crystal fault. High-precision and high-sensitivity semiconductor pressure detecting devices are realized with reduced affection by crystal fault.

Abstract: A user-manipulable sensor apparatus is provided for allowing a user to input, through hand manipulation of a movable member, motion in six degrees of freedom: translational motion in the X, Y, and Z axes, and rotation about each of those three axes. The apparatus includes a central member which acts as a stationary reference, and a user-manipulable member, such as a spherical, hollow member which substantially surrounds the central member. Flexible wire or in-line strain gauges are coupled between the central member and the inside surface of the user-manipulable member, to hold the user-manipulable member in a quiescent position, relative to a position of the central member. Accordingly, there is no need for additional support members for holding the user-manipulable member in position. Manipulation of the user-manipulable member causes tension on various ones of the strain gauges. The strain gauges produce signals, from which the motion of the user-manipulable member may be computed.

Abstract: A horn switch assembly including an airbag module cover, a bend sensor and a backing plate. The module cover has a front outer face and a rear inner face deformably depressible from the front face. A plurality of parallel, spaced-apart, elongated force concentration ribs are located on the rear inner face of the cover. The bend sensor is positioned under the force concentrators and includes a flexible substrate and a variable resistance circuit connectable to a horn control circuit. The variable resistance circuit has a plurality of spaced-apart resistive elements connected by a plurality of conductive strips. The variable resistance circuit is arranged in a plural of parallel spaced-apart columns adhered to the substrate so that the columns are generally perpendicular to the force concentration ribs and each resistive element is positioned under a force concentration rib. The generally rigid backing plate has a forward surface positioned under the bend sensor.

Abstract: A notebook computer or other electronic device has a flexible cable interconnecting electronic circuitry in a base with electronic circuitry in a cover. A flexible potentiometer is coupled to said flexible cable in a location which bends when said cover is opened and closed with respect to the base. The resistance of the flexible potentiometer has a first value when the cover is closed and has a second value when the cover is open. A detection circuit is responsive to the resistance of the flexible potentiometer and generates an output signal which indicates whether the cover is open or closed.

Abstract: A load cell device includes a load cell structure formed of a suitable metal and including vertically spaced apart, generally parallel horizontal elements integrally formed with longitudinally spaced apart, generally parallel vertical elements. Flexures interconnect each horizontal element with the vertical elements. A bending beam extends between and is interconnected with the horizontal or vertical elements. When a load is applied vertically and perpendicularly to one of the horizontal elements, the load cell structure will elastically deform as a parallelogram to thereby transfer shear force to the bending beam to cause shear-induced bending of the latter. Strain gages or frequency resonator crystal elements sense the shear-induced bending and are embodied in electronic circuitry which produces an output signal caused by deformation of the bending beam. The electronic circuitry is operable to convert the output signal to a perceptive force readout.

Abstract: A weighing apparatus is put forward for weighing a load carried by a load support provided with front and rear wheel assemblies each having at least one member which deforms as a result of the load. The apparatus comprises a plurality of strain transducers to be affixed respectively to the members. Each of the transducers includes a pair of spaced apart brackets to be fixedly secured to the corresponding member such that their upper ends come closer to one another when the corresponding member is deformed, and an elongated load cell having opposite ends attached respectively to the upper ends of the brackets. The load cell is provided with strain sensing elements for producing an electrical strain signal indicative of a strain variation substantially along a longitudinal axis of the load cell.

Abstract: A transducer which includes a central portion (12) having two longitudinally extending parallel rigid beam members (14,16) and two transverse parallel flexure members (30,32) which extend between the two rigid beam members (14,16) at right angles thereto. The rigid beam members (14,16) include end element portions (18,20). Flexure joints (58,60) and mounting portions (62,64) are located longitudinally outboard of the flexure joints (58,60). The flexure members (30,32) each include two cutout portions (34,36,40,42) defining flexure points. Strain gauges (46,48,50,52) are placed in the vicinity of the cutout portions (34,36,40,42) and are electrically connected into a bridge to produce an electrical signal output indicative of the load on the vehicle. The transducer is mounted by means of a mounting element (79) which includes two opposing mounting pad portions (82,84) and an intermedicate center portion (86).

Abstract: An extensometric sensor for measuring stresses acting on a drilling element at a bottom of a well, with the sensor including a first measurement zone formed from at least two traction blades, on which are mounted measurement gauges, connected at their ends by uprights so as to form a first deformable parallelogram, with the traction blades being oriented in a first direction. A second measurement zone is formed of at least two torsion blades, on which are mounted measurement gauges, connected by cross pieces so as to form a second deformable parallelogram, with the torsion blades being oriented in a second direction perpendicular to the first direction. The first and second zones are connected and the same is mounted on a drilling element, with the cross pieces and uprights having large dimensions with respect to the torsion blades and the traction blades.

Abstract: High tensile electrically-conductive filaments 1 are connected to the two ends of an electrically-conductive elastic block 2 and the whole is embedded within an elastic covering 3. As the sensor is put under tension the elastic block stretches and the resistance of the sensor, as measured between the two sets of filaments 1, increases proportionally to the degree of extension.

Abstract: A strain gauge primarily designed for dynamic measurements and requiring very little force to produce a change in length. The strain gauge is alternately concave and convex in shape, such as a sinusoidal curve with nodes of low resistance on the convex portions and strain gauges of high resistance on the concave portions. The gauge is unbonded and can be stretched with very little force. The strain gauge is utilized in an instrument to monitor infant respiration and detect episodes of apnea.

Abstract: A low level strain gage transducer including housing which supports a strain member having a fixed end member and a free end member in the form of a cup, the free end member supported by a folded arm arrangement including one or more arms which permits the element being monitored for strain forces to pivot with respect to the cup so as to to accommodate any mis-alignment forces applied to the cup that would otherwise generate bending forces resulting in erroneous strain measurements.

Abstract: A pressure sensor that utilizes an extension type conductive elastomer that will exhibit a decrease in its electrical resistance in response to an extension thereto. Like sheets of the conductive elastomer and an electrically insulative elastomer are overlaid and sandwiched between supporting members within a housing of the pressure sensor. The housing and each supporting member are preferably cylindrical or ring shaped, and which conductive elastomer has a pair of spaced electrodes electrically connected thereto at opposite points on its periphery. The periphery of the electrically insulative elastomer is squeezed continuously in a circle between the supporting members, while that of the conductive elastomer that includes recesses is squeezed therebetween discontinuously in the sections between the electrodes.

Abstract: An elastomeric electro-conductive device (10) capable of providing within a predetermined range of elastic elongation (.lambda.) of the device (10) sensory signals representative of elastic elongation (.lambda.) imposed on the device includes an elastomeric electro-conductive member (11) bonded to an elastomeric substrate (12). Member (11) and substrate (12) have substantially similar resistance-to-stretch characteristics .phi. within the predetermined range. On a Mooney Plot for (.lambda..sup.-1) values in the range 0.5 to 0.8 .phi. is substantially constant at 0.4 M Nm.sup.-2.

Abstract: Apparatus for removably connecting a strain cell to a polished rod of a well pumping unit and for preventing the development of strain cell output signals due to bending of the polished rod. The strain cell is connected to a frame member which can be clamped to the polished rod where strain cell output signals are obtained due to a change in tensile load on the rod. A pair of hinges, between the frame member and the polished rod, minimizes the development of strain cell output signals due to bending of the polished rod. The frame member can be adapted to mount on a variety of sizes of polished rods. The apparatus can be removed or replaced without the use of special skills or special equipment.

Abstract: A respiration and heart rate monitoring apparatus includes a mechanical-electric apparatus for detecting chest movements and electrodes for detecting electric impulses associated with heartbeat. A highly sensitive detector includes a transducer crystal mounted in bridge-like configuration on pair of spaced piers connected by at least one flexible beam member. The transducer crystal and electrodes may be connected to circuitry for producing indications of respiration and heart rate. The circuitry blocks detection of chest motion substantially coincident with the impulses associated with heartbeat to inhibit erroneous indications of respiration caused by chest motion due to heartbeat. The circuitry also may block small, single polarity signals to inhibit erroneous indications of respiration caused by muscle noise.

Abstract: A load cell temperature compensation system (10) for accurately measuring a force load applied to an external member (18) during environmentally varying temperature values. The load cell temperature compensation system (10) includes a standard load cell (12) which is rigidly mounted on a load cell mounting plate (20). The load cell mounting plate (20) is fixedly secured to the external member (18) which has an external force load applied thereto. The temperature compensation system (10) further includes a force load application mechanism (40) which transmits a predetermined force load to the load cell (12) responsive to the external force load applied to the external member (18). A mechanism for maintaining a constant reference load force (60) is provided to maintain a substantially constant reference load force on the load cell (12) independent of temperature variations applied to the external member (18).

Abstract: A strain gage element system includes a spring flexure member on which strain gages of convention design are mounted, and a heat shrinkable waterproof tube that is placed over the gage and the support and shrunk into place. The spring flexure member is formed so that it has a substantially constant peripheral length about the perimeter of any cross-sectional plane perpendicular to the longitudinal axis of the spring flexure member. The heat shrinkable tube must be selected in size and shrinkage characteristics to tightly envelope and shrink against the gage and spring flexure member and seal the gage completely to prevent moisture of any kind from getting into contact with the gage.

Abstract: An extensometer having two spaced-apart mounting bases adapted to be mounted on a load-bearing structure with its axis of sensitivity intersecting the axis along which load-induced strains are generated at 45.degree.. The extensometer includes a pair of parallel links connecting the mounting bases through respective flexure hinges. In one embodiment, one of the links is also connected to one of the bases through an intermediate flexure hinge so that the link deforms responsive to relative movement applied between the bases along the axis of sensitivity. A strain gauge mounted on this link measures the magnitude of the deformation. In a second embodiment, a strain-instrumented measurement beam extends between the two links so that it deforms responsive to pivotal movement of the links as the mounting bases move in opposite directions along the axis of sensitivity. This embodiment of extensometer may be mounted on the load-bearing structure through three or more mounting points.

Abstract: This invention relates to improvements in weldable strain gages of the type comprising a strain-sensing filament mechanically coupled to a strain-deformable housing. In a preferred embodiment of the invention, the strain-sensing filament comprises a carbon strand.

Abstract: A transducer for measuring the load of a vehicle employing an equalizing beam suspension. In an equalizing beam suspension a pair of tandem wheels are supported by opposite ends of a pair of transversely spaced, center-mounted equalizing beams. Each equalizing beam carries one of the transducers which measures the deflection of the respective equalizing beam responsive to vehicle loading. The transducer includes a push rod clamped to the equalizing beam and extending into a measurement block which is clamped to a different point on the equalizing beam. The measurement block contains a strain gauge instrumented cantilever beam against which the motion transmitting bar abuts. Consequently, the cantilever beam deflects responsive to movement of the motion transmitting bar toward and away from the measurement block produced by load induced deflections of the equalizing beams. The measurement block is essentially a plurality of stacked plates, one of which forms the cantilever beam.

Abstract: A strain sensor or extensiometer with electrical output designed to measure relative displacements between two axially spaced points on a stressed structure comprising an elongated body with two end sections and a centrally located flexible beam extending in a direction perpendicular to the longitudinal axis of the sensor body. Relative displacements of the end sections generate two opposing symmetrical torques at the ends of the beam. These torques or bending moments are impressed onto the beam through two sets of flexible bridges which are symmetrically located but unequally spaced on opposite sides of the beam. These two torques or couples cause the beam to bend evenly over its entire length. Resistance strain gages bonded to both sides of the beam at its center measure this bending.

Abstract: Strain measurement apparatus comprises a rigid support arranged to be secured against the surface of a structure. One or more resiliently deformable carrier elements provided with strain gauges mounted in said support are urged against the surface by the securing of the support to engage the surface at regions spaced from the region of securing of the support and thereby the strains at said regions of engagement are translated directly into deformation of the carrier element or elements to produce measurement signals from the strain gauges. The engagement pressure is transmitted to the elements through resilient means that limit its magnitude while allowing the apparatus to be firmly secured to the surface.

Abstract: An electromechanical transducer is provided which employs a piezoresistive substrate support body of semiconductive material of which a first type N or P and a lineal resistor composed of material of a second type (P or N) formed on one surface thereof. The support body has a reduced neck intermediate two pads. The lineal resistor extends between the pads and across the neck on one side of the support body. The lineal resistor is formed by diffusing semiconductive material of the second type of conductivity into the substrate material. Strain is detected by measuring the change in resistance of the lineal resistor. When the transducer is subjected to strain, the resistance changes by an amount depending on the strain. While the electrical current flows through the resistor, heat developed in the resistors flows into the neck and then is conducted through the flaring portions of the neck to the pads and then to an object under test.

Abstract: A load measuring system for a tandem-wheeled vehicle. The tandem axles of the vehicle engage opposite ends of two transversely spaced equalizing beams having their midpoints pivotally supporting the vehicle. Deflections of the equalizing beams and front axle, responsive to loading of the vehicle, are sensed by a load cell transducer mounted on each equalizing beam and on the front axle. An amplifying circuit receives the transducer outputs and drives a load indicator. The load indicator provides a visual indication of front and rear wheel axle loading with respect to a preset maximum load point.

Abstract: This invention relates to a transducer assembly for measuring loads in flexible sheet material, and to a method of making the transducer assembly.A strain gauged transducer plate is bonded between first and second sheets of flexible material, and a lead out cable from the strain gauge is sandwiched between spaced, mating PTFE (polytetrafluoroethylene) tapes attached to each flexible sheet. The cable is arranged in a generally sinusoidal pattern so that the cable crosses the space between the tapes at a plurality of locations throughout the length of the tapes and so that at each location the cable crosses the space in a direction generally perpendicular to the longitudinal direction thereof, thereby preventing damage and breakage of the tapes due to operational flexing of the transducer assembly.In a preferred embodiment, the transducer plate is secured in an aperture in a woven fabric sheet which is then bonded between the flexible sheets.

Abstract: A transducer or accelerometer employs at least one slot or gap located in a seismic mass of a block-like configuration. The relative displacement of the opposing faces of the block, due to the slot, is monitored by means of a shim or similar metallic member, which spans the slot. Secured to the shim is a piezoresistive strain gage whose size and dimensions become relatively independent of the dimension of the slot, therefore enabling accurate and reliable strain detection without attendant temperature problems.

Abstract: A myocardium wall thickness measuring transducer comprises a circular beam of high compliance and an elongated spike which extends in the plane in which the beam is disposed. The spike is connected at one point to the beam while a working end of the spike to which a barb is attached, extends through an opening in the beam at a substantially diametrically opposite point. The beam portion, surrounding the opening, is free to move or be displaced relative to the spike. A sensitive strain gauge is bonded to the beam to sense changes in the tension thereof. The working end of the spike is inserted through the epicardium into the myocardium so that the spike and the beam are in a plane substantially perpendicular to the epicardium at the point of insertion. The spike is inserted, to a depth at which a minimal beam deforming force is applied by the myocardium to the beam portion surrounding the opening.

Abstract: A strain gauge or a bridge comprising four strain gauges is arranged on a support such that the strain gauge(s) is (are) situated in a neutral zone. The support is secured to the object to be measured on both ends, preferably by means of screws. Between the end portions which are screwed down and the central portion accommodating the strain gauges, the support has a zone of low bending rigidity.The support can be very readily manufactured from a strip of material whose longitudinal sides are flanged so that a U-shaped profile is obtained. Flanges can also be formed only at the centre near the strain gauges, so that the zones of low bending rigidity are automatically formed.The transducer is intended first of all to be fitted on shafts of existing lorries in order to measure the shaft load.