Belden Inc.

Cooper Industries, Inc.

John W Kincaid

William A King

Robert E Ward

Leonard J Visser

Robert J Biegon

James A Krabec

Anatoly Tsaliovich

Paul B Miller

A cable for use in carrying electrical signals in the audio frequency range. The cable includes an elongate metallic core which can be positioned at the center of the cable. In the case of the coaxial cable, a sleeve of a dielectric material is positioned about the core and a metallic shield is located outwardly of the sleeve and coaxially with the core. The cable also includes a layer formed of ferrite positioned between the sleeve and the shield which substantially increases the inductance of the cable without a corresponding substantial increase in the energy loss so that the cable exhibits substantially constant phase velocity characteristics across the audio frequency band. The ferrite layer can be formed by a series of discrete ferrite sleeves or the ferrite layer might be formed by an extruded thermoplastic having a high loading of ferrite powder. A method of using the cable is also disclosed.

Audio cable

An automatic cable assembly testing apparatus and procedure. The connectors at each end of a cable assembly are isolated from the cable and from a test source. Each connector is then injected with a plurality of test frequencies and the leakage currents sensed for each of these tests. The leakage current for a particular test is compared against a corresponding reference level and pass/fail lamps are used to provide a visual indication of the test results. The sequence of tests for each end of a cable assembly over a range of frequencies can either be accomplished either automatically or manually. The preferred embodiment illustrates a microprocessor based controller for operating the system.

Method and apparatus for testing shielded cable assemblies

An electrical cable includes a core, a jacket and improved shielding with unexpectably low transfer impedance. The shielding includes an inner foil laminate, a braided sleeve, and an outer foil laminate, each foil laminate having at least one conductive layer and at least one strength-giving non-conductive layer. At least one of the foils includes a shorting fold to limit the slot effect. Preferably, the inner foil has two conductive layers, and the outer foil has the shorting fold.

Multiply shielded coaxial cable with very low transfer impedance

A method for measuring surface transfer impedance of shielded cable within a frequency range below about 1 GHz is implemented with a single test fixture. The test fixture provides a conductive cylindrical chamber which opens for installation of a sample of shielded cable. The ends of the chamber are blocked by ferrite toroids to prevent radiation of high frequency electromagnetic energy. One end of the cylindrical chamber may be externally short-circuited to the cable shielding for low frequency measurements. A current source connects between the sample shielding and the conductive chamber boundary at the other end of the chamber. Current flow at low frequencies is limited to the region between the current source and the short circuit. Current flow at high frequency is limited to the region between the toroids. The cable shielding and the fixture body beyond the toroids are short-circuited for high-frequency tests and open-circuited for low frequency tests. The induced voltage in the cable is measured through feed-throughs provided in the test fixture. The current source uses an isolation transformer to avoid ground loops in the low-frequency range.

Method and apparatus for measuring the surface transfer impedance of a

A multi-shielded transmission cable has no 'slots' in the shielding so that signal attenuation and distortion are minimized. A shielding tape for the ready manufacture of the cable has at least one conducting layer and an insulating layer and is folded at or near its longitudinal median. When the tape is wrapped about a cable core, the ends of the tape overlap so as to effect physical and electrical contact thereby avoiding slots. A heat-sensitive adhesive strip may be applied to the tape so that the shielding is bonded to the core during the step of extruding a protective jacket over the shielding tape.

Slotless multi-shielded cable and tape therefor

A shielded flat electrical cable is formed of a plurality of twisted pairs of conductors. Individual conductors of each conductor pair are twisted about each other for at least one portion of their mutual length. The conductors are laminated to a film to maintain predetermined spacing and the electrical parameters of the cable. In a preferred embodiment, the shielding comprises a wider and a narrower tape, each having a conductive layer and an insulating strength-giving layer. The tapes are disposed on opposite sides of the core of the cable. The wider tape wraps around the edges of the core and overlies portions of the narrower tape so as to make electrical contact therewith, avoiding a slot effect.

Shielded twisted-pair flat electrical cable

Two embodiments of a triboelectric transducer cable for generating a signal in response to movement or deformation of the cable each include multiple insulated central conductors, a semi-conductive wrapping separately surrounding each of the insulated central conductors with an additional conductor arranged in electrically conductive contact with the semi-conductive wrapping and a protective jacket surrounding the cable assembly.

Triboelectric transducer cable

Improved shielding members and electric cable constructions which utilize these shielding members are described. Various configurations of the shielding members can be used to enclose a single cable circuit consisting of one or more conductors in two concentric metallic shielding layers fabricated from a single shielding member which provides excellent electrical isolation for the cable circuit. Generally, the shielding members comprise an elongated ribbon of insulating material and a pair of elongated foil strips arranged in parallel relationship with the ribbon. The foil strips are bonded to opposite sides of the ribbon and each has an elongated edge generally in alignment with opposite elongated edges of the ribbon. The selective use of layers of heat sensitive sealing material for sealing the shielding layers protects the cable circuits from moisture.

Electric cables with improved shielding members

An improved shielding member and electric cable constructions which utilize this shielding member are described, the design of the shielding member allowing two cable circuits, each consisting of one or more conductors to be wrapped in and electrically isolated by a single shielding member. The shielding member comprises an elongated ribbon of insulating material and a pair of elongated foil strips arranged in a parallel relationship with the ribbon, the foil strips being bonded to opposite sides of the ribbon and each of the foil strips having an elongated edge generally in alignment with opposite elongated edges of the ribbon. The shielding member is wound in a generally S-shaped configuration forming two envelopes, each of the cable circuits being encased in, and electrically isolated by, one of the envelopes.

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Batavia, IL, United States of America

John W Kincaid