Abstract: A process and apparatus for filling multi-conductor cables, particularly a telecommunication cable with several insulated wires surrounded by a covering and a sheath, with a mixture of powders which expand with the absorption of moisture. The conductors are fed in spaced relation into the entrance of a casing having an interior, frusto-conical wall which decreases in diameter from its entrance to its exit. The exit is small in diameter compared to the entrance so that the conductors converge as they pass from the entrance to the exit. Intermediate the entrance and the exit, the conductors are subjected to the powders which are caused to follow a helicoidal course by a screw which directs them toward the exit. Due to the shape of the casing wall, the powders are forced toward the conductors.

Abstract: Sheathed electrical heating elements containing MgO heat conductive, electrical insulating material having an additive of fine particles of spherically shaped fused ZrO.sub.2 to increase the electrical resistivity and maintain favorable tap density and flow properties. The spherically shaped ZrO.sub.2 particles are formed by gravitationally separating the ZrO.sub.2 particles from ground fused zircon (ZrO.sub.2.SiO.sub.2).

Abstract: Electrical conducting cable which is insensitive to nuclear radiation comprising at least one conductive core, at least one layer of an insulating substance surrounding said conductive core and at least one conductive sheath surrounding said insulating layer, wherein the diameter .phi..sub.D of the sheath, the diameter .phi..sub.B of the conductive core, the diameter of .phi..sub.C of the insulating layer are linked by the equation: ##EQU1## F.sub.1 representing the .beta..sup.- radiation fraction from the core reaching the sheath, F.sub.2 representing the .beta..sup.- radiation fraction from the sheath which reaches the core, the insulating substance being constituted by a mixture of at least two metal oxides.

Abstract: The conductors of a cable core unit are powder filled by passing the core unit through a fluidized bed of powder with the conductors substantially closed together. The filled cable core unit can be wrapped with tape after exit from the fluidized bed. Cable cores may be filled also by passing them through a fluidized bed. The core units of the cores may be closed together or separated, but the conductors of each unit are closed together.

Abstract: For powder filling of cables, in a fluidized powder bed, it has been proposed to pass the cable core through the bed in a substantially closed condition. There is a limit to the number of conductors a core can have for effective filling. In the present invention the cable core is opened up into a number of core units by passing through an opening member. The opening member is freely ridable on the cable core and has a hole for each unit. The opener is held against a support member and an air bearing formed between the two members. Air is also usually fed to the holes in the opener member through which the core units pass to prevent flow of powder out from the bed. The opening member can be positioned in the fluidized bed or outside immediately prior to passage of the cable core through the bed. The units are each in a substantially closed condition in the bed and the units close to a single core also in the bed.

Abstract: Compacted, granular, fused magnesia used as thermally-conducting electrical insulation in tubular, electrical resistance elements is substantially improved in thermal conductivity through the addition of 0.1 to 10.0 percent of a glass comprising CaO, B.sub.2 O.sub.3 and optionally Al.sub.2 O.sub.3 and method of making said tubular, electrical resistance elements.

Abstract: A refractory, granular electrically insulative composition useful as an embedding composition for electric heating coils comprises fused and granulated, possibly ground, difficultly fusible, ceramic and possibly oxide-ceramic material having polyalkylsiloxane, e.g. polymethylsiloxane, or polyarylsiloxane admixed in a proportion of from 0.5 to 5.0% added weight. Use of the composition is suitable with tubular heaters which have been produced with it and which, after manufacture and before being brought into use, have been subjected to a heat treatment at a temperature of at least 65.degree. C, for a period of at least 10 minutes. An electrical heating element comprises a housing which is embedded in the composition wherein the ceramic and possibly oxide-ceramic material has been ground.