DE4013764A1 - Shading ring - for electronic check of slits in conveyor belts - Google Patents

Abstract

The tendency of conveyor belts to develop longitudinal splits is monitored by the electronic supervision of embedded shading rings (1) formed by a spliced metal rope. Such a shading ring (1) includes, e.g. a spliced metal wire rope with firmly joined ends of the strands of e.g. seven pairs of strands (2-8) which are aligned side-by-side. Both strand ends are shortened, leaving an overlap of 3-5 mm. The thus prepared overlap is joined by a soft solder technique. The other strands can be included in the joint. ADVANTAGE - Such shading rings have a long life and retain their conductivity.

Description

The invention relates to short-circuit rings made of spliced Me tall wire ropes with permanently electrically connected connections Strand ends are manufactured and for installation in conveyor belts for Purposes of electronic monitoring of slit endangered Conveyor belts are provided.

As with the indestructibility of these built-in short-circuit rings known electronic monitoring devices on the Unver of the conveyor belt to be monitored is closed it is important that their electrical conductivity change over the course of the Time does not change so unfavorably that it leads to false reports the surveillance system is coming.

The electrical resistance of the built-in short-circuit ring may increase Therefore, do not enlarge it so that surveillance for intact can no longer take place because of sufficient electrical magnetic signal transmission is no longer present.

This is where the long-term stability of the electrical resistance comes from the installation short-circuit rings are of great importance.

Changes in long-term stability can occur once across cut reduction, but also through contact resistance at the Set the endless closure to a shorting ring.

Cross-sectional reductions occur with unfavorable pre-stress The rope material from which the short-circuit rings are made are due to permanent break in the course of the operating time.

Increase contact resistance in the area of the endless closure unsuitable technology or wrong choice of materials.

There has been no lack of proposals in the past, these Improve vulnerabilities.

DE-OS 22 46 139 proposes a drill connection of the individual Strands, of which a rope is known to exist. Contact me tion techniques of this type, including known splicing techniques count, however, have not proven themselves in practice since it is too Infiltration of the open contact points by the Vulka plastic rubber can come. Another source of interference in the area of the contact point a chemical reaction between sulfur in the rubber mass and z. B. zinc as surfaces Protection or adhesion promoter of the ropes of the built-in short-circuit rings with the result that the surfaces in the course of a multi-mo natural operating time a lower conductivity than in Reach original state.  

Another proposal (D-OS 34 41 742) assumes that ver Drilled strand ends for the production of installation short rings in low melting metal alloys or made conductive Plastics are embedded to wi against chemical influences to create strong connections.

Although the chemical reaction at the junction below tied, passes through the force flow of the concerned Rope arranged drill connection, which is also hard and un is flexible, a load such that the immit can be protruded from the rope assembly at almost a right angle the stranded wire connections due to permanent bending stress short operating time fail and their electrical connection cut open.

One of the reasons for this is the mechanical fixation required enveloping strand ends by force-twisting the respective strand ends before the step of covering.

Another teaching, D-OS 38 11 533 suggests that the side lead ends are melted spherically. In Another embodiment is the manufacture of the splice connection completely dispensed with and the rope ends directly by Ver melt connected together. Although this procedure too electrically conductive connections is an acceptable Only then the service life of the built-in short-circuit ring guaranteed if it is due to the melting of the Seilma terials arising temperature only on the fusion point can be restricted, otherwise there is an adverse structural change rope material cannot be avoided. Since this is only with a relatively high amount of equipment can be realized a profitability of the short-circuit rings to be produced in this way not easily achieved.

In D-OS 20 30 796 to avoid the infinite closing local bending stresses caused by welding this disadvantage is eliminated in that the strands or rope ends phased out and in a known from the splicing technology Immerse yourself in the rope network. Even with this procedure face up after a short time due to rubber infiltration and the Influence of chemical elements in the conveyor belt rubber unfavorable changes changes in the contact points.

Another way to make electrical endless closing more conductive D-AS 22 48 070 describes elements. Wires are used or ray wire strands, which are connected by connecting links in the form of Clamping sleeves are connected so that there is a short-circuit ring can be made. The disadvantage of this method is the application of clamping sleeves, which can only be made via frictional contact the electrical conductivity of the conductor loop created in this way manufactures. In this process, too, the previously mentioned steps occur Phenomena of rubber infiltration and chemical reaction to the metal of the wires with the result that the electri The conductivity of the conductor loop has changed to an impermissibly high level. The use of clamping sleeves in a loose wire composite  Forming a conductor loop also has the disadvantage of one Notch effect between wire and ferrule with the result that at these points with alternating bending stress due to the movement conditions of the surrounding rubber of the conveyor belt the service life the conductor loop is limited inadmissibly.

The present invention has therefore set itself the task Shorting rings from ropes to create a great life last and keep their electrical conductivity constant.

This object is achieved in that the Her position of the endless connection of the metal cable in known Splicing technology, individual pairs of wire ends to be connected, for example seven, each placed side by side without force be that they are close to the rope, whereby any lit. zenende maintains its original path. The other lit. Because of the rope twist, zenende is right next to the former Strand end. Both ends of the wire are shortened so that one mutual coverage of 3. . . 5 mm is reached. The so prepared connection point is then with known Soft soldering process connected, in addition to the secure connection of the respective wire ends also an additional connection he is created with the other strands of the rope. So that will achieved that during the subsequent vulcanization the respective Strands are not electrically isolated from each other, but in each case together at the strand connection points are connected. It is therefore important to ensure that during the soldering process in addition to the respective pairs of strands, the other strands mitver be soldered and the solder does not get unnecessarily far into the cable tape pulls in, so that the flexibility of the rope does not velvet suffers.

An embodiment of the invention is shown in the drawing represents and is described in more detail below. It shows the

Fig. 1 shows a partial section of a built-short-circuit ring 1, for example, seven in distances from each other by splicing laterally outwardly extended Litzenendenpaare 2 to 8.

Fig. 2 shows two strand ends 9 and 10 , which are prepared for the soldering process and form, for example, the pair of strand ends 2 or any other.

Fig. 3 shows the solder joint 11, for example, the pair of strands 2 with the rest of the rope assembly.

It is not necessary that in the manufacture of the Short-circuit ring each strand is connected to itself, son but there can be any wire ends from opposite end of the rope. Overall, because of the Redundancy to create all available strands to form the so the short-circuit ring.  

The forces from installation during the belt stretching To keep the short-circuit ring away, it is advantageous to do this used rope to form waves. As research shows have, it is also advantageous, the stranded connections depending because in the non-curved part of the undulating Lay ropes to keep stretching forces away from the connection.

In a further embodiment of the invention, the respective gene distances of the stranded connections so chosen that they at Making the regular curl inevitably all in the non-curved section of the rope arrive when the first Strand connection is arranged in the non-curved part.

Claims (3)

1. Short-circuit ring made of a spliced metal wire rope with spaced strand ends in pairs for installation in a conveyor belt for the purpose of known electronic slit monitoring, characterized in that the strand ends to be tied are placed next to each other without force coming from their stranding lines and are so long that the Coverage of both ends is about 3 to 5 mm and then soft soldered together with the remaining strands. 2. Short-circuit ring according to claim 1, characterized in that the wire ends to be soldered are each in the straight zone of wavy ropes. 3. short-circuit ring according to claim 1 and 2, characterized in that the respective distances between the stranded connections to be soldered be chosen so that they are used in the production of the corrugation are necessarily housed in the straight zone.