Disclosed herein is an electrical apparatus comprising a housing having an aperture extending between an inner and an outer surface, an electrical cord including an inner wire and an outer sheath including a strain relief portion comprising a first enlarged part engaging the housing outer surface and a second enlarged part of lesser size than the first enlarged part, extending through the aperture and including therein, inwardly of the housing inner surface, a groove extending at least partially...

A strain indicator of the type wherein a change in length of a strain member produces a change in color of a visual indicator. An indicator area and a light-absorbing indicator fluid are encapsulated in a member that also includes a window. The capsule is fastened to the strain member with an adhesive. A change in length of the strain member causes the indicator area to become separated from the window with the result that light-absorbing indicator fluid is caused to flow between the indicator a...

A strain sensor has a surface wave device deposited on a substrate. The surface wave device is connected into an oscillator circuit oscillating within a predetermined frequency range. A mechanical strain is induced in the substrate to alter the frequency of oscillation of the surface wave oscillator.

A strain gage is disclosed comprising a backing strip and a strain grid having enlarged terminal lengths. Elongated tabs having integral, tapered connectors are also bonded to the backing strip. The connectors are bonded to the enlarged terminal lengths and are angled therefrom at approximately 45.degree. - 65.degree. from the direction of major strain when the gage is bonded to a test specimen. The tabs are also disposed in the same angular relationship. A cover sheet overlies the grid and tabs...

A strain indicator of the type wherein a change in length of a strain member produces movement of an indicator member. Such movement, in the elastic range of the fastener material, is essentially linear and in proportion to the stress being applied to the fastener. When, however, a preset strain limit within the fastener is exceeded the indicator element is biased in an upward direction giving an immediate visual indication of that fact.

Disclosed is a strain grommet for firmly holding one end of an electric cord. The grommet consists of a cylindrical body adapted to be opened and closed freely by means of an open cut therein and a hat-shaped fitting body. In use, the cylindrical body is fastened around the slit end of the cord and the unraveled portion of the covering braid is laid back over the outer surface of the cylindrical body. The hat-shaped fitting body is then pressed down over the cylindrical body thereby immobilizing...

A relief wire terminating system with particular regard to a strain relief means provided as an integral part of the system. At the rearward or termination portion of the system, side walls define a channel for receiving an insulated wire. At the rearmost extremity, a tab extends from the top of each wall at an angle, downward and inward into the space. The tabs terminate in edges defining a wire passing space between them, and below them, a wire restraining space. The tabs act on the wire to ta...

The present invention provides a strain gauge comprising a resistive layer. The resistive layer comprises metallic or semiconducting nanoparticles or aggregates thereof in which the nanoparticles or aggregates thereof are separated by insulating and/or semiconducting material.

A strain detector includes an insulating substrate, a power electrode, output electrodes and a ground electrode which are disposed over the insulating substrate, a strain-resistance element provided over the insulating substrate and coupled to the power electrode, the output electrodes and the ground electrode, a protective layer over the strain-resistance element, a frame ground electrode. The insulating substrate includes a stainless steel board, a protective coat on the stainless steel board,...

Strain gage apparatus of the type in which a pair of elements, connected at spaced points to a specimen under test, move relative to each other as the specimen is loaded to effect a change in an electrical signal indicative of the magnitude of the strain. Means are provided to maintain relative movement of the aforesaid elements the same and proportional to strain regardless of whether the strain occurs along the axis of the specimen or is due to bending. This is accomplished by inserting pivots...