A strain sensor includes a quartz crystal element 9 having a resonant frequency which is dependent on strain imposed on it. The crystal element 9 is caused to vibrate at its resonant frequency by pulses of light transmitted along an optical fibre 5 from a remote location indicated generally at 1. A signal produced by the vibration at the resonant frequency is taken from electrodes 10 and 12 and amplified at 13 and 14 before being used to switch on and off a switch 15 controlling a light source 1...

A strain sensor comprises an optical waveguide having a plurality of reflecting structure (Bragg grating) along its length. Each structure reflects light at a different characteristic wavelength (.lambda..sub.1 to .lambda..sub.n+1) which changes in dependence on a change of physical length of at least part of the reflecting structure. The reflectivity of reflecting structures which reflect at characteristic wavelengths which are adjacent to each other (.lambda..sub.1 and .lambda..sub.2 or .lambd...

A new device and method for providing strain relief to soft-jacketed cables includes a base with a mounting portion and a tubular extension having a plurality of deflectable arms, each of which are provided with a pad. Upon tightening of a nut having a tapered inner channel, the deflectable arms and pads radially converge about the cable. The pads evenly spread the gripping forces created by the convergence of the deflectable arms, thereby preventing damage to the wires within the soft-jacketed ...

A strain relief for protection of electrical and other cords extending from a component. The strain relief is made from a hard plug piece which attaches to the case or housing of the component. The cord extends through this plug piece via a passageway. This plug piece has a plurality of holes therethrough which connect the passageway with its outer surface. An molded jacket is molded onto the plug piece, wherein the injected material extends through the holes, into the passageway, and surroundin...

A strain detector wherein the efficiency of a detecting coil is improved to improve the sensitivity of the strain detector. The strain detector comprises a magnetic layer made of a soft magnetic material having a high permeability and fixedly mounted on an outer periphery of a driven shaft strain of which is to be detected, and a detecting coil disposed around the magnetic layer with a gap left therebetween for detecting a variation of the permeability arising from strain of the magnetic layer c...

A strain detector wherein the efficiency of a detecting coil is improved to improve the sensitivity of the strain detector. The strain detector comprises a magnetic layer made of a soft magnetic material having a high permeability and fixedly mounted on an outer periphery of a driven shaft strain of which is to be detected, and a detecting coil disposed around the magnetic layer with a gap left therebetween for detecting a variation of the permeability arising from strain of the magnetic layer c...

A strain detector wherein external and internal magnetic fields are magnetically separated from each other to eliminate an influence of such disturbance magnetic field to assure accurate and stabilized detection of strain in a drive shaft. The detector comprises a magnetic layer made of a soft magnetic material having a high permeability and suitable magnetostriction fixedly mounted on an outer periphery of a driven shaft, a pair of bearings or bearing stands made of a soft magnetic material hav...

The probe unit includes a small central gaging beam portion, spaced end blocks adapted to be bolted or otherwise clamped to the structure to be tested, and hinge plate portions connecting the blocks to the central portion in planes offset from the axis of the gaging beam. The hinge plates are relatively thin, and hence flexible, in the direction of the clamping attachment pressures, relieving the gaging beam of and significant initial bending stress in case of misalignment of the attaching surfa...

There is disclosed a connector (20) for terminating to a plurality of conductors (64). The connector includes a housing (24) having conductor terminating contacts (26) secured therein and defining an axis. First and second terminating covers (28,30) are adapted to be secured to the housing (24) from opposed directions, transverse to the axis of the contacts in a terminating position in which the conductors (64) are terminated to respective ones of the contacts (26), with the terminated conductor...

A strain transducer is adapted to measure strain at a chosen depth below the surface of a workpiece, such as at the neutral axis of a draft bar. The transducer has a hollow cylindrical plug (6) projecting from a co-axial shoulder (7) of slightly larger diameter, the distal end of the plug being force fitted with a disc-like diaphragm (9) on which strain gauges (10) are mounted. These are on the inside face, and connections (11) extend up inside the plug to encapsulated electronic circuitry at th...