DE1803404A1 - Electrical insulating or heating tapes that can be stretched lengthways and crossways - Google Patents

Description

In the longitudinal and guise direction stretchable electrical insulating ~ upper ~ heaters When insulating electrical machines or other electrical devices it is often necessary uniformly wrapped areas around irregularly formed To manufacture parts. To achieve a practically uniform thickness of the insulation without enclosed voids, in most cases the use of a stretchable one is Isolation material required. For many types of applications, stretchable materials have insufficient intrinsic strength for the required electrical insulation properties. It is therefore common practice to reinforce stretchable insulating materials Glass fabric or glass fibers or other reinforcing fibers inserted. The reinforcing ones However, fibers are generally not pluggable themselves. So if the most amplified If the product itself is to be stretchable, it is necessary to reinforce it in a weave to deliver, which enables the stretchability of the first product.

There are already various types of binding of this type known, but each has drawbacks, either in strength or in strength the production. In US Pat. No. 3,252,833 a stretchable tape is described, in which the basic pattern of parallel, sinusoidal or zigzag fibers with a Intertwined with a multitude of rectilinear fragile threads. The tissue will impregnated with a stretchable material such as organopolysiloxane elastomers and After the elastomeric material has been impregnated and hardened, the tape is stretched, around the looped fibers at the points between the loops of the zigzag fibers to break, whereby it is achieved that the tape in both lateral and can be stretched in the transverse direction. That described in the referenced patent However, the tape is rather weak in the transverse direction as after breaking of the straight threads nothing is present except for the inherent strength of the elastomer which prevents the tape from tearing when a transverse force is applied will.

The present invention therefore relates to the longitudinal and transverse directions stretchable electrical insulation or heating tapes made from a reinforcing fabric insert, which has been impregnated with a stretchable material, which is characterized by are that as reinforcing fabric inserts such be used, that of a first group of rectilinear ones substantially parallel to the longitudinal direction threads of destructible material running through the fabric, a second group of Threads in a zigzag arrangement, which are essentially parallel to each other with respect to each other their longitudinal direction, with a thread of the second group, a pair adjacent threads of the first group wraps around and a third group of threads in a zigzag arrangement, which are also substantially parallel to each other as regards their longitudinal direction, with one pad of the third group, a pair of the paths of the second group at the points of closest approach of their axes wraps around each other, consists.

As used herein, the term "zigzag" generally includes both sinusoidal arrangements and arrangements in which the fiber direction suddenly changes.

It was also found that instead of the relatively weak rectilinear Fibers also heat-destructible materials, for example at the hardening temperature of the impregnant melt, can be used, with a dimensional stability achieved during the impregnation and any subsequent coating measures will. It was also found that Use of a group of Zigzag fibers. 8U8 electrically conductive material, such as graphite, the same fabric including impregnation for the manufacture of electrical heating cables can be used.

The invention can best be explained with reference to the accompanying drawings wherein Figure 1 is a fragmentary view of a fabric used as a reinforcement Ribbon insert, Figure 2 is a similar view as in Figure 1 but with a terminating edge, FIG. 3 shows a cross section through a complete band, FIG. 4 a graphical one Representation of a tape production device, FIG. 5 a partial view of a heating tape, which has been produced on the tape according to FIG. 3 and FIG. 6 is a partial view of a fabric similar to Figure 1, but which additionally has twisted longitudinal threads, which wraps around the wrapped zigzag fibers.

Let us now consider the drawings in detail, with the same Numbers mean the same parts.

In Figure 1, a fabric is shown, the multiple threads 11 of the first Group that are fairly straight and practically parallel to the line convergence of the tape.

In each case a pair of adjacent threads 11 of the first group are of wrapped around the strands 12 of the second group in a general zigzag arrangement or wound around; the threads of the second group also run essentially parallel to each other in terms of their longitudinal direction.

The pads 19 of the third group wrap around or wrap around each an adjacent pair of the threads 12 of the second group at or near the points the closest approach of their axes to each other. The threads of the third group extend also in a general zigzag arrangement and generally run parallel to each other in terms of their longitudinal direction.

The group of the first, second and third threads form a fabric saponification or reinforcement ribs or strips for a, for example, in Figure 3 in cross section tape shown, wherein the fabric is covered with a stretchable material 14 e.g.

has been impregnated with an organopolysiloxane elastomer.

The relatively straight running first threads 11 can easily fragile material, with a smaller diameter than the second or third thread groups 12 and 13 or instead of a lower melting one Material for reasons to be shown later.

When added strength to the edges of the woven tape if desired, the tape can be formed with a tail edge as shown in FIG will. The final edge can, for example, from a pair in addition Twisted threads 15 and 16 exist which enclose one of the first threads 11 or intercept and connect it with the second thread 12. For easier handling If necessary, the relatively straight first threads 11 can also be spaced apart be knotted around the second and third pad groups 12 and 13 at their points of contact to intercept with the threads 11 or to enclose.

As a further alternative, the fabric stiffening or reinforcing rib can be used 17 according to FIG. 6 can be achieved. Here are the threads 11 of the first group of Fabric from Figure is replaced by a pair of twisted threads 31 and 32, these twisted threads 31 and 32 are preferably threads of the same type as the threads 11. While the second and third threads 12 and 13 are the first threads in the fabric Loop around according to Figure 1, the twisted threads 31 and 32 enclose the wound second and third threads 12 and 13 in the fabric according to FIG. 6 as shown under 35.

If additional edge stiffening of the belt is required, can the fabric according to Figure 6 in the same way as in Figure 2 with a terminating edge be provided.

If necessary, the threads 32 and 33 can be knotted at intervals, instead of twisted to encircle the undulating second and third threads.

In Figure 4 is a schematic representation of a device for Impregnation of the fabric shown in Figure 1 or 2 to form a tape, which is shown in Figure 3 in cross section. Instead, the fabric can can be used according to Figure 6 for tape production.

A supply of tissue, commonly referred to as 17, is obtained from a supply roll 18 unwound and passed through an extruder 19, which has a supply of uncured elastomeric material 20 contains. The extruder 19 is provided with an outlet opening equipped, which includes the entire bandwidth and also the side edges, so that the fabric is completely enclosed by the extruded material. After the extrusion, the tape coated with the soft extrusion compound is over a heated drum 21 out, which with a power plant an electrical Energy source 22 is equipped by a sliding ring bushing combination. Of the Transport path of the impregnated fabric strip over the surface of the heated The drum and the temperature of the drum are adjusted so that the hardening of the Impregnating agent 14 takes place and possibly the destruction of the cohesion of the rectilinear threads 11, ao that only the second and third threads 12 and tX as Reinforcement links of the entire band are left behind that then on a roll 23 can be wound up. Instead of or in addition to the heated one Drum can of course be a hot air oven for curing or other known ones Curing devices are used.

If the structural cohesion of the first threads 11 instead of through Heat destructible threads by breaking these threads can be a sentence used by rolling rollers rotating at different speeds, according to US Pat. No. 3,253,833 to break the fibers and thus a To achieve stretchability in the lateral direction.

The impregnation material can be extruded onto the tape in various shapes be, for example, with bevelled edges on each side of the tape to make a lighter one Allow wrapping. Optionally, an additional extrusion of additional layers take place, for example, an adhesive film in a known manner can be applied before or after curing.

If instead of the second and third threads 12 and 13 from electrical insulating material, such as glass fibers or threads for one of these thread layers electrically conductive material we used, such as copper or graphite, can be a .electrically Resistant heating bench can be produced, as already mentioned. So is for example In Figure 5, a pair of electrodes 24 and 25 shown, which with the opposite Ends of the conductive threads is connected and also to a power source 26. For example, the tape can be wrapped over an object 27, e.g. a water pipe to protect it from freezing.

Numerous other modifications are also within the scope of protection and variations on the subject matter described above.

Claims (9)

P a t e n t a n s p r ü c h e 1. Electrical insulating or heating tapes that can be stretched in longitudinal and transverse directions made of a reinforcing fabric insert, which is impregnated with a stretchable material has been shown that it is used as reinforcing fabric inserts those used are those from a first group of rectilinear, essentially threads made of destructible material running parallel to the longitudinal direction of the fabric, a second group of threads in a zigzag arrangement that are substantially parallel to each other in terms of their longitudinal direction, each with a thread of the second group wraps around a pair of adjacent threads of the first group and one third group of threads in a zigzag arrangement, which are also essentially parallel to each other in terms of their longitudinal direction, each with a thread of the third group a pair of the threads of the second group at the points of the closest Approach of their axes wrapped around each other exist. 2. Electrical insulating or heating tapes according to claim 1, d a d u r c h e k e k e n n n e i n e t that such reinforcing fabric inlay is used which are also designed with lateral end edges. 3. Electrical insulating or heating tapes according to claim 2, d a d u r c h g e k e n n n z e i c h n e t that the end edges by a pair in addition twisted threads that loop around one of the threads of the first group and this so connect with a thread of the second group, are formed. 4. Electrical insulating or heating tapes according to claim 1 and 2, d a d u r g e k e nn n n e i n e t that the rectilinear threads of the first group should be replaced with a pair of twisted strands. 5. Electrical insulating or heating baths according to claim 1 to 4, d a it is clear that the threads of the first group are made of heat consist of destructible material. 6. Electrical insulating or heating tapes according to claim 1 to 5, d a it is indicated that the pedagogues of the first group are made up of one Material that melts at the curing temperature of the impregnating agent. 7. Electrical insulating or heating tape according to claim 1 to 4, d a It is noted that the threads of the first group are made of fragile Material. 8. Electric Heizbändar according to claim 1 to 7, d a -d u r c h g It is not noted that the threads of the second group are made of conductive material and the threads of the third group are made of insulating material. 9. Electrical insulating tapes according to claim 1 to 7 d s d u r c h g It is noted that the threads of the second and third groups of insulating material exist.