Cable Technology Laboratories, Inc.

General Cable Corporation

Gk Technologies, Incorporated, General Cable Company Division

Carlos Katz

Attila F Dima

George Bahder

George S Eager, Jr

Amicam C Zidon

Louis A Bopp

Adolf S Knott

Bruce Bier

Long lengths of a heat-shrinkable sleeve for use in splicing electrical cables and the like are manufactured by providing an elongated impermeable core having a smooth outer surface, extruding an elongated sleeve around and in contact with the core, the sleeve having a smooth inner surface conforming to the outer surface of the core, and effecting an initial expansion of a portion of the sleeve to a larger diameter in an expansion zone so that the sleeve separates from the core and leaves a space between the sleeve and core. A fluid is introduced into the space under pressure via a fitting at the downstream end of the sleeve while continuously advancing the sleeve and core through the expansion zone. To begin the process, a permeable core is used, and the sleeve is extruded around and in contact with the permeable core. A fluid is introduced under pressure from a fitting upstream or downstream of the expansion zone through the permeable core to the inside of the sleeve in the expansion zone, and the leading end of the impermeable core is welded to amd trailing end of the permeable core at a location upstream of the expansion zone. The sleeve has a composite structure comprising an inner compound and an outer compound, the inner and outer compounds having different characteristics. In a first crosshead, the inner compound an a thin layer of outer compound are applied, and the balance of the outer compound is applied around the sleeve in a second crosshead. Between the two crossheads, liquid nitrogen cools and stabilizes the inchoate sleeve.

Apparatus and method for manufacturing heat-shrinkable sleeve using

A joint structure for covering a joint between cables is provided in which an insulation structure extends over and beyond cut back ends of insulation layers of the cables, but terminates at a distance ahead of cut back ends of insulation shield layers of the cables. The insulation structure of the joint structure includes a multi-layered, heat shrinkable tube with its ends beveled or 'feathered'. In assembling the joint, the tube is positioned to overlie the cable conductors and the insulation layers of the cables and is shrunk thereover so as to terminate at a distance from the cut back ends of the insulation shield layers of the cables. The heat shrinkable tube can be manufactured with feathered edges, so that no additional time or labor is required to shape the sleeve when the joint is assembled. The joint structure also includes a semiconductive conductor shield member applied in successive convoluted layers over the exposed conductors of the joint prior to application of the heat shrunk tube. The conductor shield member is an elongated strip formed with a narrowed forward portion and a somewhat wider rear portion, which is feathered along either longitudinal edge and overlaps the cable insulation layers. The conductor shield member is constructed to be pre-curled so as to speed assembly of the joint. A termination of a single conductor is also disclosed.

Electrical cable joint and electrical cable termination and methods of

Voltage stress control cones for high voltage cable terminations are produced by premolding and radially expanding to mechanically prestress. The mechanically prestressed premolded cone is slipped over the insulation of a cable end and heat relaxed to shrink tightly over the cable. The cone is fabricated from cross-linkable polyethylene or other cross-linkable polymeric material having substantially the same electrical and thermal characteristics as the cross-linked polymeric insulation of the cable. A semiconductive layer of cross-linked polymeric material provides the transition between the insulation of the cone and the semiconductive insulation shield of the cable.

Premolded mechanically prestressed voltage stress control cones for high

The insulation shield in a power cable having thick polymeric insulation is constructed of a metallic layer radially spaced from but in electrical communication with an inner semiconducting layer by an intervening helical wrap of a semiconducting or high dielectric constant longitudinal structurally resiliently compressible substantially shape recoverable element. Various elements are described, both hollow and solid, with and without one flat longitudinal surface, and of both monolithic plastic and composite plastic and metal construction.

High voltage electric power cable with thermal expansion accommodation

Long lengths of a heat-shrinkable sleeve for use in splicing electrical cables and the like are made in a continuous process. The sleeve is formed around a permeable core, and the core and sleeve are advanced together in an axial direction, the leading end of the advancing sleeve being hermetically sealed. The core and sleeve pass through a heating station, thereby heating a portion of at least the sleeve, and a fluid is introduced under pressure into the core, thereby internally pressurizing the sleeve to effect a radial expansion of the heated portion thereof. The core and sleeve then pass through a cooling station, thereby cooling the expanded sleeve to stabilize it. A stress graded compound also for use in splicing electrical cables and the like is made by heating a dimethyl silicone liquid to remove entrapped gas and mixing the liquid with a silicone carbide powder having a particle size capable of passing through a 400 mesh screen. The volumetric proportion of powder to 1 part liquid is within the range of 0.5 part to 2.0 parts.

Apparatus for making shrinkable tubing

Method for manufacturing heat shrinkable tubing

This invention relates to stress control cones for terminations of high-voltage power transmission cables. Such cones are used beyond the end of the cable insulation shielding, and for the purpose of providing thicker insulation for reducing the stress at and beyond the unshielded insulation on a high-voltage power cable. This invention builds up greater thickness of insulation beyond the end of the cable insulation shield, preferably by wrapping the cable with layers of insulating tapes that are then heated and fused to one another and to the outside surface of the cable insulation. The hot build-up of additional insulation is fused, or brought to incipient fusion, to merge the build-up to the cable insulation and the build-up layers to one another, instead of using preformed stress relief cones which are unsuitable for very high voltage. The build-up material is shaped to the most effective contour by the application of force from hydraulically-operated molding shapes made of metal and forced against the build-up by hydraulic motors attached to portable shaping apparatus.

Apparatus for molding stress control cones insitu on the terminations of

This cable for high-voltage, alternating current power transmission cables not only reduces the access of moisture into the cable but reduces access of moisture to the inner face of the insulation to such an extent as to make the cable highly resistant to the formation of electrochemical trees in the solid extruded insulation of the cable. A compressible layer of closed cell, foamed plastic is extruded over the outside surface of the insulation; and a metallic shield fits tightly around the compressible layer, the metallic shield being a longitudinally folded tape with a lap seam which is preferably bonded to prevent ingress of air or other fluid into the cable. If the conductor is stranded, sealant is used to prevent ingress of moisture, or of air, and the humidity it contains into the cable at cable ends.

Solid dielectric cable resistant to electrochemical trees

This invention makes extruded, vulcanized, high voltage cables insulated with thermosetting compounds at much higher rates of production and with superior insulation of reduced thickness and with reduced cavities or voids in the insulation. As the cable comes from an extruder, it passes into a curing chamber with a heat booster that quickly raises the insulation to a temperature at which it is cured much more quickly than with steam heating of the prior art. A high temperature liquid in contact with the insulation maintains the high temperature; and because of the greater curing heat, the cable can travel through the curing chamber at a faster rate and into a cooling tube where it contacts with a cooling liquid under high pressure. The insulation compound is treated to reduce the size of cavities; and the high pressure maintained by the curing and cooling mediums prevent expansion of cavities before the insulation is set.

Growing community of inventors

Edison, NJ, United States of America

Carlos Katz