Showing papers by "General Cable published in 1978"

Relationship between composition, density and refractive index for germania silica glasses

Abstract: The density and the refractive index for various compositions of binary SiO2GeO2 glass prepared by a flame deposition technique, similar to that used to make low-loss optical waveguides, have been measured by standard Archimedes method and the Becke line method, respectively The density as a function of composition is calculated considering the effective volume of the ions contained in the glass to be invariant The refractive index as a function of composition is also calculated, based on the Lorenz-Lorenz equation, by computing the electronic polarizability of fused silica and germania All calculated results are in good agreement with the observed data

Emergency standby air drying back-up system

Abstract: In some critical use, air-drying systems, 100% back-up capability is desired. The problem has been that an idle standby unit requires considerable time to reach full capability for dry air delivery. This invention bleeds enough dry air from the operating primary unit through parts of the idle back-up unit to maintain any dynamic conditions that are necessary to keep the standby unit ready for immediate use in the event of a failure of the primary unit.

Reel lifting apparatus

Abstract: Reel lifting apparatus utilizing a truck-like vehicle having a wheeled framework with a subframe mounted on the framework. A truck bed body is mounted upon the subframe and overlies the subframe. An elongate rod-like member is provided which is pivotally mounted on the body so that it extends in a direction at right angles to the longitudinal axis of the vehicle. First and second arms are mounted in fixed spaced apart positions on the rod-like member. The arms are formed so that they are capable of carrying a reel mounted upon a spindle. A plate is secured to the rod-like member. An L-shaped member has one end of the same pivotally connected to the subframe and the other end pivotally connected to the plate. An actuator is pivotaly connected to the subframe and to the L-shaped member at a point intermediate the ends of the L-shaped member for causing the movement of the arms through an angle in excess of 135°. An in-line motor drive train is mounted upon one of the arms. Means is provided for connecting the drive train to the reel so that the reel can be driven.

Telephone cable with improved shield combination

Abstract: Communication cables with cores that have groups of conductor pairs, that carry messages in opposite directions, in the same cable present the problem of crosstalk between the different groups. With the increase in carrier frequency that is used for communication, the crosstalk problem increases, and cables that were acceptable for lower frequency are no longer adequate. This invention provides more efficient shielding; is suitable for higher frequencies; provides a stronger cable structure; and reduces corrosion of the shielding.

Progress in the Determination of AC/DC Resistance Ratios of Pipe-Type Cable Systems

Abstract: This paper presents a summary of measurements made to determine ac/dc resistance ratios of large conductor, high voltage pipe-type cables of modern design. The method and circuit used are described. The measured ac/dc resistance ratios of similar size compact segmental copper conductor aluminum conductor cables are presented. The effect of temperature on the ac/dc resistance ratios is reported. Test results are compared with ac/dc resistance ratio calculations made using the Neher-McGrath method. The accuracy of ac/dc resistance ratios which can be anticipated by the use of the Neher-McGrath method is improved by the use of a transverse conductance factor kpc for cables in cradle configuration and a new factor for calculating in-pipe resistance ratios. The measurements have resulted in the development of cables with lower ac resistance.

Power and control cables having flexible polyolefin insulation

Abstract: This invention is an improved insulation for electric cables and an improved method of making the insulation. Cross linked polyethylene insulation is too stiff, particularly in high voltage cables which require a thick layer of insulation. Copolymers of polypropylene have electrical properties substantially equal to those of polyethylene, but do not have the necessary physical strength and have to be filled with clay or other filler that provides the required strength but degrades the electrical characteristics. A novel feature of this method is the utilization of the screw of the extruder to effect a mixing of the ingredients in an improved polymer system for cable insulation.

Development of ±400 KV/±High and Medium-Pressure Oil-Filled Paper Insulated DC Power Cable System

Abstract: This paper describes the steps to be taken to optimize the design of oil-paper insulated power cable for high voltage dc operation. Experimental data is presented on models to establish the steady-state dc dielectric strength and the switching surge polarity reversal dielectric strength of oil-paper insulations. Laboratory data is presented on factory made prototype cables tested under voltage stress conditions applicable to a ±600 kV dc system. Optimized designs of high-pressure oil-filled pipe-type and medium-pressure oil-filled self-contained cables are presented.

End seals for pre-connectorized telephone cables

Abstract: This invention provides relatively simple and inexpensive end seals for protecting the ends of telephone cables that are preconnectorized at the factory or distribution center. These end seals are moisture-proof, able to retain pressure and afford mechanical protection while the preconnectorized cables are carried in inventory and during handling to a place of use in the field.

Apparatus and method for assembling communications cable containing fiber optic conductors

Abstract: This invention is an improved apparatus and method for making fiber optic communication cables by cutting accurate helical grooves in a layer of insulation surrounding the surface of a strength member, and inserting the fiberglass conductors into the grooves with fillers and spacers around and between the glass conductors to protect them from damage. Helically wrapped binders and heat barrier tapes may be wrapped over the assembly with any additional binder threads or tapes as may be necessary to hold the heat barrier in place.

Method of making flame retardant EPR unipass telephone drop wire

Abstract: This telephone drop wire is insulated with an improved insulation made from a semi-crystalline, low molecular weight, ethylene-propylene diene terpolymer (EPDM) which is used for a unipass insulation. The insulation has improved electrical properties which permit thinner sections of insulation to be used, so that the overall cross-section of the drop wire is of lower cost, higher temperature rating, and with moisture resistance suitable for use buried underground. The insulation is also much tougher for use where abrasion is a factor.

Development and Installation of an Optical-Fiber Cable for Communications

Abstract: An optical-fiber cable has been developed which has a superior performance; which has high reliability; which can be installed in lengths of 1 km or more by direct burial or in ducts without additional protection; which can be handled with the equipment and personnel regularly employed for conventional wire cables; which will withstand the rough treatment normally encountered in a field environment. The paper describes cable construction; measured results; methods of installation, splicing, testing and pressurization; specialized hardware; instruments and tools developed for field use. Several systems employing this type of cable have been installed and have been placed under observation with automatic monitoring equipment.

Standardized gland assembly for cable connections

Abstract: This improved gland assembly is primarily for use with mineral insulated cables. The same gland body and lock nut is used for cables regardless of the cable diameter. The dimensions of the compression ring are the same, except for the ring bore, which matches the diameter of the cable. The lock nut bottoms on a shoulder to prevent overtightening of the nut and risk of fracturing the sheath of the cable.