Abstract: A device for determining when a threaded joint for steel tubes having a male element (1) with external threads (3) with a screw limiting stop (5), and a female element (2) with corresponding internal threads (4) and a corresponding screw limiting stop (6) is properly made up is provided. The device comprises a strain gauge (12) and means (10, 11) for applying said gauge on the external surface of the female element (2) such that the gauge can measure superficial deformations of the female element (2) in the longitudinal direction along one of the generatrix of the female element.

Abstract: A holding device for mounting a shear strain gauge 14 in an airplane axle 1 in which the shear strain gauge 14 consists of a coil part 18 with two magnet coils 19 spaced apart from each other and of a disk part 20. The disk part 20 has a disk 21 which, in normal position, extends equidistant between the magnet coils 19. The holding device has two holding rings 16 and 17 arranged axially at a given distance from each other, the coil part being adapted to be fastened to the one holding ring 16 thereof and the disk part 20 to the other holding ring 17. The holding rings 16 and 17 are developed with radial resilience and with a smaller outside diameter than the inside diameter of the airplane axle. They have radially protruding holding lugs 23 which rest under initial spring tension against the inner wall of the airplane axle 1.

Abstract: The device comprises central anchor means firmly anchored to a lug (3), e.g. the smooth middle portion of a rod (10) capable of being thermally fitted in a smooth round hole (7) through the lug (3) together with first and second independent fixing means (26, 26') disposed on either side of said central anchor means, e.g. two threaded end portions (27, 27') fitted with nuts (28, 28', 29, 29').

Abstract: A fastener arrangement for clamping a sensor element to a member whose deformation is to be monitored so as to elimiate signal distortions due to the clamping process and to settling phenomena. The sensor element is formed at its contact point with the member to be monitored by pressing between a die and counter-die as the clamping screws are tightened to provide a form-fit closure of the sensor element with the member to be monitored. The die and counter-die are formed on the adjacent surfaces of the member to be monitored and a torsion member; between which surfaces, the sensor element lies. The screw support member can be arranged to isolate the screw turning moments from the sensor element jointly with the form-fit closure feature.

Abstract: The load-sensitive element of a load cell is provided with reduced-thickness portions for endowing the cell with flexibility, and a strain gauge is bonded to each reduced-thickness portion. A deposited aluminum tape or a deposited aluminum film, comprising a substrate and a deposited aluminum layer provided on the substrate, is bonded over each strain gauge by using an adhesive, thereby covering each strain gauge with a deposited aluminum layer. Alternatively, each strain gauge is covered with aluminum foil or a deposited aluminum film bonded in place through the intermediary of a rubber sheet interposed between the load-sensitive element and the foil or film, a space being provided around the strain gauge. Furthermore, the strain gauge is covered by a Teflon sheet non-adhesively, and further, a covering member such as a deposited aluminum film or tape covers the strain gauge from the top of the Teflon sheet.

Abstract: Structure for mounting a load cell enclosure on a bending beam is disclosed, wherein the load cell enclosure has a pair of mounting flanges extending from the enclosure and the flanges each have opposed mounting and exposed surfaces. A swivel footed clamp is provided for contacting each flange exposed surface and a beam surface in a manner to firmly secure the flange mounting surfaces to the beam.

Abstract: A vapor and moistureproof electrical component such as an electrical load cell is formed by mixing a light oil such as mineral oil with liquid silicone gel and then curing the mixture in place to encapsulate an electrical component.

Abstract: A microbending fiber optic acoustic sensor. A point hydrophone according to a first preferred embodiment of the present Invention includes two opposed pistons which are subjected to an acoustic pressure wave. In response to the pressure wave, the opposed pistons push a pair of deformer plates against an optical fiber to deform the fiber thereby intensity modulating an optical signal passing through the fiber. An extended hydrophone according to a second preferred embodiment of the present Invention includes an optical fiber wound in a helical groove formed in a cylindrical surface. A plurality of parallel axial slots are located in a spaced-apart relationship to each other at positions about the cylindrical surface and are oriented in parallel with the axis of the cylindrical surface. Each axial slot intersects with the helical groove at a plurality of locations and has a depth greater than the depth of the groove.

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: A temperature sensor is formed by mounting a force-sensitive resonator on a resilient or non-resilient base structure, preferably in an enclosure such that thermally induced expansions or contractions of the base structure apply a stress to the resonator. The resonant frequency of the resonator is measured to provide an indication of the temperature of the base structure and resonator.

Abstract: A temperature sensor is formed by mounting a force-sensitive resonator on a resilient or non-resilient base structure, preferably in an enclosure such that thermally induced expansions or contractions of the base structure apply a stress to the resonator. The resonant frequency of the resonator is measured to provide an indication of the temperature of the base structure and resonator.

Abstract: A load-cell balance having a parallelogram load cell body constituted by a stationary column, movable column and two arms connected between these columns, each arm having thin-walled flexible portions to which adhered are strain gauges. Each strain gauge is coated and sealed by a coating made of a material of butyl rubber group so as to be protected against moisture. The coating permits a free deflection of deflectable parts of the balance, even when the load is small, while maintaining a good moisture proof nature, so that the reliability of the balance is much enhanced.

Abstract: A magnetically mountable device for sensing deformation from loadings on machine members. The device includes a strain sensing transducer, brackets between which the transducer is supported, and magnetic bracket mounts which permit the transducer to be easily mounted on the machine member by virtue of magnetic attraction forces between the mounts and the force carrying member and yet be readily repositionable on the member so as to facilitate location of points of maximum stress concentrations during a working cycle of the machine.

Abstract: A method for sensing a change in deflection of an axle due to load is provided by attaching a deflection sensing device at a specific longitudinal location along the axle at which the bending moment is not affected by a stop member contacting the axle. The stop member limits pivotal movement of the axle.