DE3405988A1 - Tension and shear securing device, which seals and is at the same time electrically isolating, on pipe connections - Google Patents

Abstract

A tension and shear securing device, which seals and is at the same time electrically isolating, on pipe connections for supply line networks consisting of ductile cast iron is provided, in which clamping elements are provided which are embedded at intervals into an elastomeric annular compound and have two steel teeth at least on their inside. These clamping elements are supported on the pipe sleeve end such that they can be displaced or pivoted and their teeth dig into the smooth insertion end of the other pipe part or pipe moulding. Each clamping element is constructed in two parts. Only the one part which has the teeth consists of steel, while the other part, which has the support and other contact surfaces with the pipe sleeve end consists of an electrically insulating ceramic material, aluminium oxide or suchlike sintered material. The two parts are firmly connected to one another, for example by bonding, over a boundary surface which is as large as possible and is arranged in a specific manner.

Description

"Sealing and at the same time electrically separating

Tensile and shear protection on pipe connections "The invention relates to a sealing and at the same time electrically separating pull and shear protection on pipe connections, esp.

for supply line networks made of ductile cast iron, with the characteristics of the preamble of claim 1.

Such a tension and thrust protection is known from DE-OS 27 54 984.

Tensile and shear protection have been used on pipe connections, esp. For supply line networks in cities or the like. Are now extraordinary proven, especially when the sealing ring and clamping elements form a single deformable Form ring body that can be easily handled and inserted at the construction site and reliably takes over both the seal and the tension and thrust protection.

In particular, the well-known Tyton seals with embedded therein Multi-toothed clamping elements also reliably secure the seal with dimensional tolerances of the spigot end that vary to a relatively large extent and pipe socket end. Since the clamping elements made of steel on the one hand on the smooth Attacking the plugging end over their teeth and on the other hand over their groove on the inwardly facing annular bead of the pipe socket end is supported on the Pipe connection points of the electrical conduction path not interrupted. This is desirable in many applications.

However, there are also use cases in which such a continuous electrical conductivity of the line consisting of several pipe lengths is not is desirable. To create an electrical separation connection in the area of the pipe connection to obtain, it is known from the aforementioned publication, at least one of the interacting surfaces on the clamping element or on the pipe socket end to be covered with a pressure-resistant layer of electrically insulating material. to for this purpose the supporting surface in question has been covered with an enamel layer.

Practice has shown that this is a sufficiently reliable electrical separation in the area of the pipe connection cannot be guaranteed.

It is the object of the invention to provide the subject matter according to the preamble # of Claim 1 so that in addition to the reliable sealing and securing against pulling and pushing forces in the area the junction too ensure a reliable electrical separation effect under all conditions is, if possible only by simply exchanging the actual Sealing element the expert can decide on the spot whether he wants the one Achieve electrical separating effect or a continuous over the connection point wants to ensure electrical conductivity, this task is made possible by the measures of claim 1 solved.

By making each clamping element from two separate parts if you have it in your hand, the two parts each meet different requirements optimally train them accordingly. So is the part that is supposed to make sure that yourself the clamping element is intended to cling to the smooth outer surface of the insertion end and has teeth for this purpose, can be made of steel. The second part, who, on the other hand, has to ensure that the tensile or thrust forces that occur are reliable be transferred to the pipe socket end and must ensure at the same time that each clamping element is in the optimal operative position by a tilting movement can pivot, can as a relatively compact part made of ceramic or other electrical insulating sintered material can be produced. It should be noted that this Part not only ensure the tiltable support of the clamping element on the pipe socket part must, but at the same time must give the security through its training that the pivoting possibility of the clamping element in the pipe socket part to a maximum permissible Swivel angle is limited. This means that the clamping element is in the maximum pivoting position can also come into direct contact with other parts of the pipe socket end. This contact option as well as the support is carried out by the compact part Ceramic of the clamping element.

The invention can be used particularly advantageously in the case of known ones Tensile and shear-proof Tyton seals, in which the clamping elements correspond to the outline of the sealing ring are adapted and embedded directly in this. Here points the pipe socket end on the one hand an inwardly facing annular bead as a support and abutment for the clamping element and the sealing ring on and at a distance including an inner shoulder, while the sealing ring as well as the clamping elements outline approximately the same foot sections in the area between the annular bead and inner shoulder engage. In this ring, the invention provides that the the electrically insulating material existing part of the clamping element with the annular bead cooperating groove and between these and the inner shoulder engaging foot portion includes.

In their external dimensions and their effect, sealing rings are here with clamping elements made only of steel and sealing rings with two-part Clamping elements according to the invention from the outside essentially identical, as well as in the handling, so that the rings can easily be exchanged for one another can. Eactlmanrl has it easily at hand at all times for a walk-through (J. electrically conductive pipeline or to decide one with electrical separation points in the area of the connections.

The two parts of the clamping elements can be firmly bonded to one another be connected. In any case, it is useful if the interface between the both parts is as large as possible and so in the cross section of the clamping element is placed that the interface areas in each tilted position of the clamping element which is approximately perpendicular to that of the tooth in engagement Line of action of force runs. This will ensure that the adhesive bond remains largely unloaded between the parts by the forces to be transmitted and the part made of ceramic in its highly stressed areas is essentially only subjected to pressure.

The invention is based on schematic drawings explained in more detail in an example.

They show: FIG. 1 in detail and in an interior view or partially cut a combined tension and shear locking ring that doubles as a sealing ring formed and known as the "Tyton seal".

FIG. 2 shows a clamping element on a larger scale and in radial section according to the invention.

FIG. 3 shows the clamping element in a view from the inside and FIG. 4 in a radial view Cut a pipe connection with a sealing and at the same time electrically separating one Pull and shear protection according to the invention.

Figure 1 shows a tried and tested combined backup and Sealing ring 1. This consists of elastomeric material and has a bead-like shape Head section 2, which is effective as the actual sealing section and a Foot portion that extends from the head portion by a radially outwardly facing annular Groove is separate. In the elastomeric sealing ring are in predetermined Distances between clamping elements 3 made of steel firmly embedded. These are essentially adapted to the contour of the sealing ring with the exception of the head section 2. Each Clamping element has at least two sharp-edged ones on its inwardly facing surface Teeth 4a, 4b, a corresponding groove on its radially outwardly facing side and a foot section 5 beyond the recess.

While in known sealing and retaining rings of this type the Clamping elements 3 consist entirely of steel, the new clamping element according to FIG. 2 and 3 made of two parts 10 and 11 that are independent of one another. The part 11 includes essentially the two teeth 4a, 4b and only this one Part 11 is made of steel. The part 10 includes the groove 17 and the by the interfaces 18 and 19 determined foot section. This part consists of an electrically insulating ceramic material, made of aluminum oxide or other electrically insulating sintered materials of correspondingly high temperature resistance and Strength. The groove 17 is determined by a radius 16 around the point 15 in Figure 2 can be pivoted.

The interface or contact area between the two parts 10 and 11 of each clamping element, as FIG. 2 shows, has a relatively large surface area. At this interface, the two parts can. B. by gluing 'firmly together be connected.

This interface is preferably not a flat surface, but a spatial surface, which is guided around the groove 17 that in each tilted position of the clamping element the interface has at least one area through which the clamping element transmitted forces run essentially in the vertical direction. For example According to FIG. 2, the interface 2 is essentially approximately perpendicular to the longest Expansion of the clamping element extending areas 12 and 14, while the intermediate Area 13 is led around the groove 17 substantially.

Figure 4 shows the installation position of the combined ring. At 20 is a referred to as the smooth insertion end of a first pipe section or ear part, while at 21 the pipe socket end a second pipe section or pipe fitting is designated. The pipe socket end has an internal extension 22 for receiving the head part 2 of the seal. This is limited by a radially inwardly facing annular bead 23, which is arranged with a spaced from it Inner shoulder 25 delimits an inwardly facing annular groove 24.

The inserted ring is a ring similar to that Ring 1 according to Figure 1 with the difference that the clamping elements are basically similar are designed as shown in FIGS. You can see that the electrically insulating material existing part 10 of the clamping element the foot portion of the clamping element as well as the entire area that determines the groove includes. The part 11 has its outermost tooth in fixed engagement with the insertion end 20. This results in a line of force 26, over which the clamping elements to Shear protection serving forces between the spigot end 20 and pipe socket end 21 transmits. It can be seen that the interface between the two parts 10 and 11 of the clamping element in this tilted position has an area which is approximately perpendicular to the line of action 26 runs.

To limit the maximum permissible tilt position of the clamping element acts the foot end of the clamping element with the surfaces delimiting the groove 24, esp. the inner shoulder 25 of the pipe socket end 21, together. Any contact between clamping torque and these parts of the pipe socket end cation only over part 10 of the clamping element take place. This ensures that in no pivot position or tilted position of the clamping element an electrical contact between the steel existing part 11 of the clamping element and the pipe socket end 21 can occur. Due to the relatively compact design of the part 10, this part, even if he Made of ceramic or the like. Material, transmit high compressive forces and also the Safe absorption of forces occurring during swiveling movements under load.

The position of the interface between the two parts 10 and 11 ensures that the forces absorbed by the part 11 made of steel are safe on the part 10 are transferred, which in turn securely to the pipe socket part 21 or its Areas 23 and 25 can transfer.

Since on the outer contour uhd the handling of the combined ring does not change anything compared to the ring according to FIG. 1, the new ring can just as easily and handled reliably and easily exchanged for the ring according to FIG. 1 if necessary will.

The new design of the clamping elements is not just for use suitable in the so-called Tyton sealing rings.

The two-part design of the clamping elements can rather be in Use the same way for other types of thrust locks as described in Various embodiments are shown in DE-OS 27 54 984 mentioned at the outset are.

Claims (4)

Claims 1. Sealing and at the same time electrically separating pull and Shear protection on pipe connections, especially for supply line networks made of ductile Cast iron, in which a smooth pipe end of a first pipe section or pipe fitting into a pipe socket end of a second pipe section or pipe fitting with the interposition an elastomer sealing ring can be inserted and several in the form of a ring in the circumferential direction distributed and embedded in the sealing ring or other elastomeric ring Steel clamping elements are provided, each having at least two teeth on its Inner surface and one with a corresponding abutment section in the pipe socket end as a pivot bearing cooperating bearing section, as well as the maximum pivot position showing limiting stop sections, with between each clamping element and the co-operating areas of the pipe socket end at least one layer made of electrically insulating material of high compressive strength is provided, thereby it is noted that each clamping element (3) is designed in two parts, only the first part (11), which comprises the teeth (4a, 4b), is made of steel, while the second part (10) comprises the bearing section and the stop sections and made of an electrically insulating ceramic material, aluminum oxide or Like sintered material consists. 2. tensile and shear protection according to claim 1, wherein the sealing ring is designed in the form of a Tyton ring, one with an inwardly facing Annular bead of the pipe socket section cooperating, outwardly open groove and one engaging between an annular bead and an inner shoulder of the pipe socket section Has foot portion and in which adapted to the Ouerschnittsumriß of the sealing ring Clamping elements are embedded, thereby g e k e n n z e i c h n e t that the out the electrically insulating material part (10) of the clamping element (3) the groove (17) cooperating with the annular bead and between these and the inner shoulder (25) engaging foot portion (18,19). 3. tension and thrust protection according to claim 1 or 2, characterized g e k e nn z e i c h n e t that the two parts (10, 11) of each clamping element by gluing are firmly connected to each other. 4. tensile and thrust protection according to one of claims 1 to 3, characterized it is noted that the interface (12-14) between the two parts (10, 11) of each clamping element (3) is placed so that it extends as large as possible and in each tilted position of the clamping element (3) has at least one area (12-14), the about perpendicular to that of the engaged tooth (4a, 4b) outgoing power transmission line (26) runs.