DE1941365U - ELECTRIC INSULATING BODY MADE OF CAST RESIN, IN PARTICULAR FOR SLEEVES AND TERMINALS OF ELECTRIC CABLES. - Google Patents

Description

.231560-3.5.61

FELTEN & GUILLEAUME CAELSWEBK AKTIENGESELLSCHAFT · COLOGNE-MÜLHEIM

Fl. 3649 Cologne-Mülheim, May 2, 1966

Electrical insulating body made of cast resin, in particular for sleeves and electrical cable terminations

In the case of electrical insulating bodies made of cast resin, which are intended for higher voltages, in particular for sleeves and closures of electrical cables, electrically conductive inserts, so-called field control electrodes, are generally required, which are usually cast into the cast resin body during manufacture. Mechanical stresses are often created by these encapsulated electrodes. This stir once, therefore, that the shrinkage occurring during the curing of the casting resin itself can not compensate for the cast electrode other hand * join ate in the operation of Gießharzkörpers temperature fluctuations that occur frequently due to the different coefficients of thermal expansion of the electrode material and the casting resin mechanical stresses on. Mechanical tensions can, however, especially in the electrical

Flo J649 May 2, 1966 - 2 -

tric field, lead to cracks in the insulating body * and the resulting Cavities can initiate a breakdown of the insulating body through ionization.

From the German patent specification 500 381 it is known in a cable sleeve filled with the usual viscous insulating compound to use a wire mesh as the field control electrode. But the individual wires of this grid are direct embedded in the insulating compound «That has the disadvantage that In the electric field, the peak effect creates increased electric field strengths directly on the surface of the wires, which in turn can lead to the breakdown of the insulating body.

The invention relates to electrical insulating bodies made of cast resin, especially for sleeves and terminations of electrical cables * with at least one insulator made of cast resin cast-in wire mesh field control electrode. According to the invention, the gaps in the wire mesh are the electrode bridged by electrically conductive casting resin »Such an electrode is flexible and resilient on all sides at the temperatures occurring during the hardening of the insulating body, like the wire mesh itself. The shrinkage occurring during the hardening of the cast resin body can therefore follow, so that none of this occurs in the insulating body mechanical tensions remain ο But also in the company No mechanical stresses arise from temperature changes because the insulating body and the electrode are made from the same basic material exist and therefore behave almost the same thermally »Besides can also * because the gaps in the wire mesh are bridged by electrically conductive casting resin, through the small Wire diameter do not develop locally increased electrical field strengths. But the electrode is also, since it is attached to it The surface as well as the surrounding insulating body is made of cast resin * which separates the two during encapsulation Parts resulting in very good adhesion embedded in such a force-fitting manner in the insulating body that there are no signs of detachment the surface of the electrode and thus in turn voids in the insulating body.

Pl. 3649 May 2, 1966 - 3 -

Preferably, the wire mesh of the electrode is at least on the Electrically stressed Seit® covered with a layer of the electrically conductive casting resin, so that this with a noticeable layer thickness protrudes over the grid wires. It is recommended for that electrically conductive casting resin a casting resin with a lower heat resistance to be chosen as for the insulator. As a result, the casting resin of the electrode softens when the insulating body is cast around it stronger and can give way particularly well. In cases where the electrode is facing inwards on one or both edges or is bent on the outside, the grid wires of the electrode advantageously run obliquely to the surface lines of the electrode, around the To avoid the formation of gaps when bending the wire mesh.

The drawing shows an exemplary embodiment in a schematic representation an electrical insulating body for a cable sleeve with a cast-in field control electrode according to the invention in FIG in longitudinal section and in Figure 2 the field control electrode individually and partially cut open.

1 denotes the insulating body made of cast resin and 3 denotes the wire mesh the field control electrode 2 cast in this. The wire grid 3 is bent inward at both edges. Its wires run at an angle to the surface lines of the electrode. The wire mesh is on all sides in a © layer 4 made of cast resin embedded, for example from a casting resin, which by adding electrically conductive material such as powdered graphite, Soot or metal powder, made electrically conductive 1st. The interior 5 of the electrode is here electrically conductive Cast resin poured out, the surface 6 of which can be used for making contact.

Claims (1)

P.Ä. 231560-3.5.66 Γ Fl. 3649 2ο May 1966 - ι - Expectations 1. Electrical insulating body made of cast resin, in particular for sleeves and terminations of electrical cables, with at least one in the out Cast-resin-made insulating body, cast-in field control electrode made of wire mesh, characterized in that the gaps in the wire mesh by electrically conductive Cast resin are bridged. 2. Insulating body according to claim 1, characterized in that the wire mesh of the electrode is covered on at least one side with a layer of electrically conductive casting resin. 5. Insulating body according to one of claims 1 and 2, characterized in that the electrically conductive casting resin of the electrode has a lower heat resistance has as the casting resin of the insulating body. k. Insulating body according to inem of claims 1 to j? with at least one edge of the electrode bent inwards or outwards, characterized in that the grid wires of the electrode run obliquely to the surface lines of the electrode.