Abstract: An insulating system is described that incorporates a cellulosic material which is impregnated with a nitrogen content no less than 0.2% by weight and a overall density not greater than 0.9 gm/cm.sup.3. This cellulosic material when impregnated by a dielectric liquid such as transformer oil, exhibits a more uniform electrical stress distribution than papers having a density greater than 0.9 gm/cm.sup.3. The insulating system thereformed is particularly useful for application in low stress areas such as the layer insulation in a distribution class transformer.

Abstract: The invention relates to a method for improving the thermal stability and dielectric integrity of a cellulosic web product. The cellulosic web is impregnated with a nitrogen donor compound such that the web contains not less than 0.2% by weight of the compound and thereafter impregnated with an aqueous vegetable protein solution at a pH of not less than about 8.5.

Abstract: A method of reducing electromagnetic re-radiation of harmonic and intermodulation products by metal structures, having at least two adjoining elements, in response to an incident electromagnetic signal (rusty bolt effect). The method comprises the application between the adjoining elements of the structure, at their junction, of a layer of a non-water soluble substance having a dielectric constant greater than 10.

Abstract: A fire-retardant and radiation resistant molded resin product is prepared by blending a resin with a halogenated acenaphthylene compound of the formula: ##STR1## wherein X is chlorine or bromine and R is alkyl, alkoxy or alkylester of 1 to 4 carbon atoms such that when m is 0, n is an integer of 2 to 8; when m is an integer of 1 to 4, n is an integer of 2 to 7 and n+m is .ltoreq.8 and when m is more than 2, R may be the same or different; and, after molding said blend, generating free radicals within said blend.

Abstract: The present invention relates to a laminated insulating paper formed of cellulose paper or papers which is adhered to at least one side of cross-linked silicone grafted polyolefine film and to an oil-filled (OF) cable which insulated by the laminated insulating paper. The laminated insulating paper has outstanding peel strength as well as excellent non-solubility and anti-swelling properties in insulating oils.

Abstract: Sealed power cables (e.g. for underground or submarine use) are often equipped with a metal sheath. A problem with some such cables is that their insulation is subject to greater thermal expansion of the cable during use than the metal sheath is capable of following. According to the present invention the metal sheath (5) is longitudinally corrugated either when the metal sheath is manufactured or by pressing a metal sheet which is originally plane over resilient ribs disposed longitudinally on the cable.

Abstract: A paper pulp insulated cable of the kind having a plurality of conductors covered with paper pulp insulation. The insulated conductors are twisted into pairs, the pairs are stranded into units and the units are built up into cores, covered with, for example, a paper wrap, aluminum, steel sheath and a polyethylene jacket. The cable has a high density of conductors. Also a method of manufacturing such cables is described.

Abstract: A paper pulp insulated cable of the kind having a plurality of conductors covered with paper pulp insulation. The insulated conductors are twisted into pairs, the pairs are stranded into units and the units are built up into cores, covered with, for example, a paper wrap, aluminum, steel sheath and a polyethylene jacket. The cable has a high density of conductors. Also a method of manufacturing such cables is described.

Abstract: The conductor wire in a dynamoelectric machine armature and the like is insulated by a single ply longitudinal wrapping of insulating material stretchable at least 12% in a longitudinal direction and at least 8% in a transverse direction without rupturing. The edges of the longitudinal wrapping are overlapped and adhesively bonded together.