Minnesota Mining and Manufacturing Company

3m Innovative Properties Company

Lawrence C Chor

Robert A Wandmacher

John T Larson

Thomas J Heyer

Brian K Molitor

A two-part system for electrical stress control includes a conformable stress control material positioned at the shield cut edge of a prepared power cable and a stress control tube over the conformable stress control material. A second region of conformable stress control material is positioned adjacent the cut end of the insulation. Relationships are revealed which relate the permittivity and dimensional parameters of the two components.

Stress control for termination of a high voltage cable

A two-part system for electrical stress control includes a non-tacky conformable stress control material that is positioned at the shield cut edge of a prepared power cable and a stress control tube over the non-tacky conformable stress control material. A second region of conformable stress control material is positioned adjacent the cut end of the insulation.

A cable closure assembly using a cold shrink, or pre-stretched, tube has a flowable material in the assembly, and an extra support core which reinforces the conventional support core that maintains the tube in a radially expanded state. The flowable material may be used to fill voids, or provide improved bonding or water resistance. The extra, or secondary, support core has an outer diameter which is approximately equal to the inner diameter of the primary support core. The secondary support core is sufficiently long to substantially support the area where the flowable material abuts the primary support core. In one embodiment particularly suited for power applications, the elastomeric tube is electrically insulative and the flowable material provides electrical stress control, and another elastomeric tube is provided having a high permittivity. The primary support core may have a varying diameter such that the tubular member has different zones with different expanded diameters. The secondary support core is preferably removed just prior to product application (leaving the larger core intact) so as to increase the product's shelf life.

Closure with flowable material and reinforcing core

An aluminum sleeve connector is applied to an aluminum conductor using multiple deep penetrations of the connector wall into the conductor. The penetrations are sufficient to at least fill the void volume between the connector and conductor in the transverse cross-section in which they lie. Each penetration causes plastic flow in the extruded material of the connector and in the conductor at their interface to minimize spring back and causes shearing at the interface to remove any oxide or other insulative coating.

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Austin, TX, United States of America

Lawrence C Chor