Coupling assembly

Pipe connection and method of manufacturing the securing device used therein

The invention relates to a pipe joint with a tensioned fastener receiving non-profiled end portions of two pipes or one end part of a pipe to be connected to a fixed object, and at least two securing devices each arranged in their own radially inwardly open ring chamber of the fastener and comprising at least one wall of the ring chamber. , locking elements distributed in the circumferential direction of the pipe, having at least one circumferential side wall extending in the circumferential direction of the tube, the radially inner edge of which is provided with an edge radially adhering to the tubular material, the securing element or several securing elements of each securing device being connected to each other.

In such a known pipe connection, the securing devices consist of about three circular segment-shaped securing elements rotatably mounted on a transverse axis in the axial plane of the pipe. The securing elements have spike-forming teeth concentrically on the circumference with their axis of rotation, which adhere to the pipes to be connected. Due to the concentricity of the teeth with respect to the axis of rotation, the securing elements rotate only when the tubes are pulled apart, so that they can only rotate up to one side wall of the individual receiving chambers. Facing this sidewall response, they continue to grip the tubes with their teeth, preventing the tubes from continuing to pull apart.

In another known pipe connection of this type, the securing elements are approximately cylindrical and the cylinders extend in the direction of the axis or circumference of the pipe, and have circumferential teeth which engage the material of the pipe35. For each securing element, one separate chamber is made in the housing of the fastener, the circumferential side walls of which limit the movement of the cylinder in the axial direction of the tube.

Also known is a pipe connection comprising securing devices, which is made in the inner surface of the fastener as an anchor ring in the form of a fracture cone, viewed from the side. The smaller diameter side of the anchoring ring has axial slits, and the lamellae between the slots interleave in the circumferential direction and form spikes adhering to the tubular material. When the pipes connected by the pipe joint are subjected to an axial tax burden and therefore retract from each other, the conical part of the anchoring ring extends radially with respect to the pipes so that the fastener presses the anchoring rings towards the pipes with greater force and prevents the pipes from continuing to separate. However, in order to raise the anchor rings to the vertical, it is necessary to bend the ring material all the way so that a large bending moment acting against the vertical lifting of the anchor ring can be overcome. Prior to the vertical rise of the anchor rings and the consequent increase in the clamping forces, a considerable axial displacement of the two pipe ends can already be achieved by moving the pipe material by means of spikes. Only when the axial displacement finally results in a greater accumulation of tubular material in front of the spikes will the vertical start-up effect become effective.

The object of the invention is to provide a pipe connection as described, which, with the easier installation of the securing devices, enables a greater axial load 30 of the pipe connection without the pipe ends moving significantly with respect to each other.

According to the invention, the object is solved in such a way that the side walls of each securing element diverge up to the side walls of the annular chambers and each of their radially inner edges forms spikes which adhere radially to the tubular material.

8726 obliqueness.

In this solution, the side walls on the joint side between the end portions of the pipe elements of the securing elements can be raised almost immediately when the pipe ends are pulled up and up, increasing the radial force acting on the penetration of the spikes into the pipe material. Also with respect to the axial forces which tend to press the ends of the tubes towards each other, the securing device provides a higher resistance. It is desirable to receive such axial pushing10 or compression forces, especially when there is still a sealing sleeve inside the fastener, the radially inner surface of which has a circumferential rib adhering between the end faces of the pipe ends to be connected. Possibly too high axial forces will not damage this rib. High axial load capacity is also desirable when the pipe joint is used as a fixed pipe holder which acts as an attachment point against which the movement of the pipes due to thermal axial elongation must be prevented. In this case, ym20, the pipe joint passes only one pipe, which it connects to a fixed object (a house wall or the like) without the need for a sealing smoky between the fastener and the pipe. The lateral support of the securing elements by means of the walls of the chamber ensures that the supported side walls of the securing elements are not spread so wide under the radial pressure of the fastener that they become out of contact with the pipe material. Rather, the radial tightening pressure is applied virtually entirely to at least the spikes of the supported sidewalls of the securing elements so that the spikes bite firmly into the tubular material, although the inclination of the sidewalls of the securing elements is relatively small to withstand high axial forces.

Preferably, care is taken to ensure that each securing device is arranged in its own ring folder.

The (through) annular chamber structure of the hitherto separated circumferential chambers, one of which is intended for each securing device, not only makes the manufacture of the chambers but also the installation of the securing devices and possibly their fastening in the fastener, since several securing elements can be installed at once. In addition, the securing elements are supported laterally on each of their side walls by means of the side walls of the ring binders.

Preferably, the cross-sectional area of ​​each ring chamber and securing element is approximately trapezoidal. The inner surfaces of the side walls of the ring chambers therefore run five times and apply additional radial compression when tightening the quick release to the free ends of the side walls of the securing elements resting on them. Further, the trapezoidal shape causes the securing element to be applied in the axial direction to the center of the ring folder.

Care can then be taken to ensure that all or some of the safety elements of each safety device are combined in one piece. This integration of the securing elements into one piece simplifies their installation and improves their cohesiveness.

Preferably, it is further provided that at least a part of each securing device is stamped from a flat spring steel-metal strip such that the longitudinal edges of the metal strip preferably have , is shaped like a circle. Such a securing device can be manufactured in a simple manner from a single metal strip.

In this case, care can be taken to ensure that the sharp tip formed during stamping is located radially inside both securing devices. This sharp tip has a relatively sharp edge and makes it easier for the spikes to penetrate the pipe material. At the same time, the cutting edge opposite the sharp tip of the same cutting surface is slightly rounded, and during tightening of the fastener the side walls of the securing elements are applied only towards the side wall of the respective ring chamber facing it, without penetrating the ring chamber side wall material. The tightening forces passing through the side walls of the securing elements are thus better directed radially towards the pipe.

Even better rounding to each cutting edge is obtained if the longitudinal edges of the metal strips are pre-rounded from the edge of the stamping tool before stamping.

The inclination of the side walls of the securing elements is approximately 0.36-0.58, preferably about 0.47. In this area, a very high degree of safety is obtained against the axial displacement of the tubes inside the fastener.

Preferably, the inner circumferential diameter of the spike tips is smaller than the inner diameter of the chamber walls. In this way, it is ensured that the tips of the spikes first adhere to the pipe material before the walls of the chambers press towards the circumference of the pipe. Most preferably, however, there is always at least a small gap between the walls of the chambers and the circumference of the pipes.

It can then be ensured that the securing devices can be pressed towards the pipes or tube with the tightening screws passed through the fastener. In this way, the adhesion effect can be considerably enhanced.

When the securing devices are supported on one side by means of the lateral walls of the chamber, the fastener casing only needs to have a total of two chamber walls in total, i.e. only one ring chamber. As practice has shown, a sufficiently high axial load resistance is still achieved for the connection provided by the pipe joint, since the spikes on the supported side of the securing device penetrate the pipe material deep enough in any case when the fastener is secured, e.g. that the spikes of the second side wall also penetrate even to a small extent radially into the tubular material.

It is preferred that only the side walls of the securing devices spaced apart are supported by the walls of the chamber. In this case, the walls of the chamber providing the support are on the axial outside of the securing devices, so that these walls of the chamber can be made at the axial ends of the fastener and thus the sheath of the fastener can simply be bent from the sheet metal.

The securing of the lateral support of the securing devices can be further improved by fastening the securing devices to the fastener, for example with screws, rivets or by spot welding.

In addition, it can be provided that the angle of inclination of the side walls of the securing devices which are not supported by the chamber walls with respect to the axis of the fastener is greater than the angle of inclination of the side walls of the securing devices supported by the chamber walls. In this construction, the unsupported side walls of the securing devices have been made to a greater extent such that they straighten in the radial plane when the axial traction loads the pipe joint. Thus, they provide a stronger adhesion of the fastener to the pipes and thus a higher axial tensile load resistance.

The invention and its modifications are described in more detail below with the aid of the drawings showing preferred embodiments. In the drawings, Fig. 1 shows a partially sectioned perspective view of a pipe joint according to the invention for connecting two pipe ends, Fig. 2 a perspective view of a part of the pipe joint securing device according to Fig. 1, Fig. 3 Fig. 5 is a partially sectioned perspective view of a modified pipe joint according to the invention for connecting two pipe ends, and Fig. 6 is a part of a pipe joint according to Fig. 5 with a slightly modified securing device.

The pipe joint according to Figure 1 operates by connecting the ends of two concentric pipes 1 and 2 of approximately equal diameter and wall thickness. The pipe connection consists of a two-part fastener 3, an annular sealing sleeve 4, tensioning screws 7 and 8 shown schematically in a dotted line with nuts securing devices 5 and 6 through threaded holes, to tighten these against the outer surfaces of the tubes 1 and 2, possibly in addition to the compressive force of the fastener 3.

The fastening screws 15 are at the securing device 5 and the fastening screws 16 at the securing device 6 and each divided into the circumference of the fastener 3.

The fastener 3 has ring chambers 17, 18 and 19 running around it, which break only in the region of the gaps between the flanges 11 and 12 of the fastener halves 13 and 14. In the longitudinal direction of the fastener 3, the ring folders 17 and 19 located at the outer ends have. each with one securing device 5, 6 and bounded by side walls 20, 21, 22 and 23, of which axially outermost sidewalls 20 and 23 form radially inwardly extending flanges and middle side walls 21 and 22 form radially inwardly projecting ribs.

The longitudinal cross-section of the ring folders 17, 18 and 19 is trapezoidal and the inner surfaces 25 delimiting the annular chambers 17 and 19 of the side walls 20-23 have a relatively large angle of inclination with respect to the longitudinal direction of the tube, as clearly shown in Fig. 4.

A rubber plastic sealing sleeve 4 protrudes axially in the middle of its inner circumferential rib 26 into the gap between the end faces of the tubes 1 and 2 to be connected, and further surrounds the end portions of the tubes 1 and 2 inside the ring chamber 18. The sealing sleeve 4 can in turn be surrounded inside the ring chamber 18 by a tightening fastening device (not shown) with radially inwardly projecting end flanges, whereby the locking device of this additional tightening fastener can be accessed through a hole in the housing of the fastener 3.

The securing devices 5 and 6 also consist of approximately trapezoidal cross-sectional locking elements 27 in a circular arc corresponding to the curvature of the ring folders 17 and 19, the side walls 28 of which form a smaller angle of inclination β1 with the longitudinal direction 25 of the tube. ^v° i was about 20-30 ° and is preferably 25, which corresponds to the oblique of the side walls 28 of the securing elements 27 (tan ^ 2 ^ 0.36-0.58, preferably about 0.47.

The radially extending edges of the securing elements 27 are provided with sawtooth-shaped spikes 29 to provide a radial grip on the tubular material. In addition, the securing elements 27 are connected to one another in the circumferential direction so as to obtain one securing ring with one separating slot or possibly two separating slots 180 ° apart, so that the diameter of the securing devices can be changed when the fastener 3 is tightened.

To manufacture the securing device 5 and 6, a flat spring steel-metal strip is stamped in the shape shown in Fig. 3. The longitudinal sides of this metal strip preferably have circular sawtooth-shaped spikes 29 and circumferentially Y- or U-shaped expanding sections 30 delimiting the side edges 28 of the securing elements 27 which have a radius of curvature corresponding approximately to the outer radius R of the tube. the me5 strip strip punched into the shape of Fig. 3 is then formed into circular arcs by bending the side walls 28 along straight lines shown in broken lines, as shown in section in Fig. 2. Bending of the side walls 28 can take place with profile rollers involving a bending tool that twists the bent metal strip into a circular arc.

When stamping a metal strip, sharp points 31 are formed on the second cutting edge of the cutting surfaces, see in particular Fig. 4, while the sharp tips 31 of the opposite cutting edges 32 in stamping necessarily have to be slightly rounded due to the five-ton cut of the stamping tool. The side walls 28 are therefore bent so that the sharp tips 31 will be located inside the pre-bent securing element 5 and 6 as seen in the radial direction.

However, even before stamping, the metal strip can be laterally rounded radially outwards from the longitudinal edges in order to obtain an even more efficient rounding of the cutting edges 32 so that the cutting edges 32 slide very reliably on the inner surfaces.

25.

The securing devices 5 and 6 are dimensioned so that after being placed in the ring folders 17 and 19, the rounded edges 32 of their side edges 28 rest on the inner surfaces 30 delimiting the ring folders 17 and 19 of the ring folder walls 20-23 and the partitions 33 (Fig. 4) on the bottom of the ring folders 17 and 19. The securing devices 5 and 6 are thus retrieved when the ring folders 17 and 19 are mounted in the middle themselves, in particular because of their trapezoidal shape. Furthermore, the inner radius of the securing devices 5 and 6 is chosen to be smaller than the inner radius R 1 of the fastener halves 13 and 14 so that the teeth 29 are located radially inwards past the side walls 20-23.

Screws 15 and 16 can be omitted, but still, if used, improve the adhesion of the securing devices 5 and 6.

Next, the case where the screws 5 15 and 16 are not used, as shown in Fig. 4, will be considered.

When the fastener 3 is tightened, the tightening force F is then transmitted through the partition wall 33 of each securing element 27 to its side walls 28. From there, forces are transmitted to the inner surfaces 25 of the side walls 28 in the radial direction 10 and through the spikes 29 to the pipe material. Part of the clamping force of the fastener 3 is transmitted through the radially bent inner surfaces 25 to the side walls 28 so that the walls 20-23 of the ring binders press the side walls 28 further radially towards the circumferential surfaces of the tubes 1 and 2. In this way, axial sliding of the spikes 29 from the outer surface of the tubes is prevented when the fastener 3 is tightened as the side walls 28 rest towards the inner surfaces 25, although the angle of inclination is relatively small. However, the small bending angle makes it possible for the side walls 28 in practice to act as push plates which can receive large axial forces, whether they be tensile or pushing forces applied to the pipes 1 and

2. If the bending angle / Λ then increases as the side walls 28 rise, then the radial compressive force of the spikes 29 in the pipe material increases and thus a stronger grip of the spikes 29 in the pipe material is ensured. The joint then provides a more secure attachment of both tubes 1 and 2, which can withstand not only high tensile forces but also high compressive forces, which could lead to sulfur compression of the sealing rib 26.

The screws 15 and 16 further substantially improve the adhesion of the securing devices 5 and 6.

In any case, the sharp tips 31 facilitate the penetration of the spikes 29 into the tubular material, while the rounding of the edge prevents the side walls 28 of the securing members 25 from adhering to the walls 20-23 of the ring binders.

Due to the different radii and R (see Fig. 4) the distance between the radially inner surfaces of the inner walls 20-23 of the ring binders from the outer surface of the tubes 1 and 2 ensures that the tightening force F is not directly transmitted through the fastener 3 or the ring binder walls 20-23 to the tubes 1 and 2.

Instead of the two flanges 11 and 12 shown in broken lines in Fig. 1 and the corresponding tightening screws, it is also possible to use a joint connecting the two halves 13 and 14 of the fastener, whether this is by means of a pivot pin or a hinge. In any case, the installation of the securing elements 27 is relatively easy due to their interconnection, since several or all of the securing elements 27 of each securing device 5 and 6 can be installed simultaneously in their respective ring folders 17 and 19. The one-piece connection of the securing elements 27 allows simple manufacture from a single metal strip.

The fastener 3 can also be used without the sealing sleeve 4 only for axial fastening of a pipe 1 or 2 to be passed through the second fastener 3, whereby the fastener 3 connects the pipe to a fixed object, for example a building wall, with a connecting device (not shown). In this case, the fastener 3 acts as a fixed tube holder and an attachment point within a set of interconnected tubes25, which tubes are mounted inside the fixed holder so as to be axially movable for thermal strain relief.

The fastener according to Figure 5 differs from the fastener according to Figures 1-4 mainly only in that it has only one circumferential annular chamber 17 'inside it, which breaks only in the region of the gap between the flanges 11 and 12 of the fastener halves 13 and 14. The annular chamber 17 'contains both securing devices 5 and 6 and is axially bounded by external side walls

20 and 23 in the form of a radially inwardly extending flange.

The axial cross-section of the annular space of the annular chamber 17 'is approximately trapezoidal, with the inner surfaces 25 delimiting the annular space of the side walls 20 and 23 having a relatively large angle of inclination / 3 with respect to the longitudinal direction of the tube.

Instead of the fastening screws 15, 16 according to Fig. 1, the means 15 'and 16' shown in dotted lines in Fig. 5 are used for fastening the securing devices 5 and 6 to the fastener casing, e.g. by screwing, riveting or spot welding11a.

The fastening means 15 'are the securing device 5 and the fastening means 16' for the securing device 6 and in each case divided into the circumference of the fastener 3.

The securing devices 5 and 6 are placed in the annular chamber 17 'so that the rounded edges 32 of their axially outer side walls 28 abut the second inner surface 25 delimiting the annular chamber 17' of the annular chamber walls 20 and 23 and their partitions 33 abut the bottom of the annular chamber 17 '.

When the fastener 3 is tightened, the radially acting clamping force F is transmitted through the partition wall 33 of each securing element 27 to their side walls 28. From them the force flow is transmitted through the spikes 29 to the pipe material, whereby the spikes 29 adhere to the pipe material. Part of the clamping force of the fastener 3 is also transmitted radially axially to the outer side walls 28 via the inclined inner surfaces 25, so that the walls 20 and 23 of the annular chamber also axially press the outer side walls 28 radially against the circumferential surfaces of the tubes 1 and 2. In this way, and due to the fact that the axially outer side walls 28 are against the inner surfaces 26, the axes of the spikes 29 are prevented from sliding off the outer surface of the tubes when the fastener 3 is tightened, although the inclination angle ^isrelatively small. However, the small angle of inclination β 2 allows the side walls 28 to function practically like sliding plates capable of receiving large axial forces on the pins 13 and 2, be they tensile or compressive forces. If the angle of inclination then increases as the side walls 28 rise, the radial compressive force exerted by the spikes 29 on the tubular material would increase and thus ensure a stronger grip of the spikes 29 in the tubular material. The joint thus thus also provides a secure fastening of the pipes 1 and 2, which, in addition to high tensile forces, also withstands high compressive forces which would cause the sealing rib 26 to break.

The modification according to Fig. 6 differs from the embodiment according to Fig. 5 only in that the axially inner side walls 28 'of each securing device 5 and 6 have a larger angle of inclination of about 60 ° with respect to the axial direction than the axially outer side walls 28, i. greater oblique to the axial direction. As a result, less material is used in the securing devices because the side walls 28 'are shorter than the side walls 28. In addition, this also makes it possible, when axial attraction is applied to the tubes 1 and 2, the side walls 28 'tend to straighten in the radial direction and to provide a stronger attachment of the fastener 3 to the tubes.

The fastening means 15 'and 16' do not need to be used if the pipes 1 and 2 are not likely to be subjected to really high axial compressive forces or if the sealing sleeve 4 inside the ring chamber 17 'is surrounded by radially inward end flanges against the axially inner facing side walls 28 (Fig. 5) or 28 '(Fig. 6) are supported axially. The end flanges of such an additional internal fastener, together with the side walls 20 and 23, would each form their own annular chamber, as in Figure 1.

The chamber walls 21 and 22 in the pipe connection according to Fig. 1, which are ribbed inside the fastener casing, are not necessary in this embodiment, so that the fastener casing can simply be bent from the sheet metal.