Pipe coupling for connecting two pipes with different outer diameters

Description

[0001] The invention relates to a pipe coupling for coupling two pipes with different outer diameters, in particular sewer pipes.

[0002] In practice, it frequently occurs that sewer pipes made of plastic, stoneware, or concrete with different diameters need to be connected. For example, a collecting pipe with an outer diameter of 265 mm might need to be connected to a supply pipe with an outer diameter of 200 mm. If no suitable rigid plastic coupling is available, or if the pipes are not axially aligned, flexible couplings must be used. These couplings must be pressure-resistant and leak-proof, and their diameter can be varied to a certain extent.

[0003] It is known to use elastomeric pipe sections that accommodate the opposing spigot ends of the pipes to be joined. The elastomeric pipe sections are typically fastened to the pipes by means of clamps. To keep the wall thickness of the elastomeric pipe section small and to allow sufficient flexibility to bridge diameter differences in the pipes to be joined, shear plates are known that are applied to the outside of the elastomeric pipe section. The clamps fasten the elastomeric pipe sections to the outside of the spigot ends of the pipes via the shear plates. In the region of the pipe with the smaller diameter, the shear plates are provided with a series of cutouts in the axial direction to allow the diameter of the shear plates to be reduced in this region when the corresponding clamp is tightened, without any overlapping of the shear plates.

[0004] A corresponding design of a pipe coupling is known from EP 3 354 953 A1. There, the end of the shear plate facing the smaller diameter pipe is provided with axially directed cutouts, the width of which either changes uniformly or has a constant width in one area and a varying width in another. The two ends of the shear plate are received in pockets formed by folding over end sections of the elastomeric pipe section, with the clamping clamps being applied to the folded-over ends of the elastomeric pipe section.

[0005] The insertion of the ends of a shear plate into folded-over end regions of an elastomeric pipe section for connecting two pipes and the application of clamping collars to the folded-over end regions of the elastomeric pipe section is also already known from DE 2 109 566 A.

[0006] German patent DE 20 2010 013 624 U1 describes shear plates with wedge-shaped cutouts. Here too, clamping collars are applied to the ends of the shear plate to fasten the elastomeric pipe section to the pipe ends to be joined.

[0007] The invention is based on the objective of providing a pipe coupling for coupling two pipes with different outer diameters by means of an elastomeric pipe section, which is simpler in design than the prior art, more cost-effective to manufacture and offers the possibility of bridging larger diameter differences between two pipes to be connected.

[0008] This problem is solved by the invention specified in the claims. Further embodiments of the invention are specified in the dependent claims.

[0009] The invention is based on the aforementioned EP 3 354 953 A1, which discloses a pipe coupling with an elastomeric pipe section in which the ends of the applied shear plate are received in pockets of the elastomeric pipe section. The elastomeric pipe section is fastened to the pipe ends to be joined by means of clamping brackets applied to the outside of the pockets.

[0010] US 8,651,532 B2 relates to a pipe coupling from the prior art and discloses the preamble of claim 1.

[0011] According to the invention, the shear plate is split axially along its length and applied to the outer circumference of the elastomeric pipe section in such a way that, at the end of the larger-diameter pipe, it can be adapted to the diameter of the larger-diameter pipe by means of a clamping screw connection, thereby clamping the elastomeric pipe section. To bridge diameter variations of the pipes to be joined, the shear plate has a series of cutouts at its other end with a width such that the diameter of the elastomeric pipe section, compressed by a clamp applied to the shear plate, can be significantly reduced in order to fit the elastomeric pipe section onto the end of the smaller-diameter pipe.The cutouts in the shear plate are each oriented obliquely to the axis and essentially have a right-angled cut shape, in which the width of the cutouts remains constant along their length.

[0012] The invention makes it possible to eliminate the need to receive the end of the shear plate in a pocket of the elastomeric pipe section on larger diameter pipes, by attaching the clamping screw connection directly to the opposite edges of the split shear plate. This also eliminates the need for a clamping collar at this end of the shear plate.

[0013] The design of the cutouts as cutouts running diagonally opposite the shear plate axis has the particular advantage that the length of the pressure surfaces remaining between the cutouts can be increased compared to cutouts running purely in the axial direction, and thus it is possible to bridge larger diameter differences of pipes to be joined compared to the prior art.

[0014] Preferably, the shear plate is formed from at least two axially oriented partial shells. This allows for easier displacement of the shear plate parts during diameter reduction and simultaneously prevents compression of the elastomeric pipe section in the circumferential direction. The partial shells are each provided with a clamping screw connection at their opposing edges at the end of the shear plate that is to be connected to the larger diameter pipe, so that even when using multiple partial shells, no clamping collar is required.

[0015] The clamping collar at the end of the shear plate, which causes the diameter adjustment of the elastomeric pipe section to the pipe of smaller diameter, can, instead of being received in a pocket of the elastomeric pipe section, preferably also be provided with an elastomeric intermediate layer, which is attached to the clamping collar in advance or has already been applied to the clamping collar during manufacturing.

[0016] The cutouts in the shear plate have essentially the same width along their length. However, they can exhibit a varying cut shape, particularly in the transition zone between the area with the larger diameter and the area where the diameter is to be reduced.

[0017] A preferred embodiment of the invention also consists in the pressure surfaces between the cutouts in the transition area between the region of the diameter to be reduced and the region of the larger diameter containing one or more openings, in particular elongated holes or slots, which are directed in the circumferential direction of the shear plate. This results in improved deflection of the pressure surfaces when the diameter of the shear plate changes.

[0018] Due to the split or multi-part shell design of the shear plate, the invention also allows adaptation to pipes with different diameters on the side of the coupling that is attached to the pipe with the larger diameter, resulting in a wide range of applications that further helps to reduce the necessary number of different couplings.

[0019] The invention is explained in more detail below using an exemplary embodiment. The figures shown are: Fig. 1 a perspective view of a coupling according to the invention. Fig. 2 a side view of the coupling. Fig. 1 Fig. 3 a perspective view of a shear plate, Fig. 4 a side view of a shear plate, Fig. 5 a split view of a shear plate, Fig. 6 a sectional view through the coupling according to the invention, and Fig. 7 a detail view of a further embodiment

[0020] The in Figure 1The illustrated coupling includes a sleeve 1, designed as an elastomeric pipe section, for connecting two pipes of different diameters, e.g., one pipe with an outer diameter of 265 mm and a second pipe with a smaller outer diameter of 200 mm. The sleeve 1 is surrounded by a pipe-section-shaped shear plate 2, which is axially split and can therefore be reduced in diameter. At the end of the sleeve that is to be connected to the pipe with the larger outer diameter, the shear plate 2 can be tightened by means of a clamping screw connection 5. This is achieved by tightening a clamping band 9, which is formed on a longitudinal edge of the shear plate 2, via a worm thread of the clamping screw connection 5. Such clamping screw connections are known as connecting elements on clamps and hose clamps in plumbing and electrical installations.

[0021] In the invention, such a connection is used in such a way that the clamping band 9 can be formed directly as a part of the shear plate located on the first longitudinal edge of the shear plate, while the worm thread of the clamping screw connection is arranged directly on the second longitudinal edge of the shear plate. The shear plate thus forms a clamping clamp itself, eliminating the need for a separate clamp to fasten the shear plate.

[0022] The shear plate 2 is provided at its second end with a series of cutouts 4, which allow the diameter of the shear plate to be significantly reduced in this area. This is achieved by tightening a clamping clamp 3, which is mounted on the area of ​​the shear plate 2 with cutouts 4, via a clamping screw connection 6 arranged on it. The worm thread of the clamping screw connection acts on the clamping band 10 of the clamping clamp 3, thereby drawing the opposing edges of the clamp 3 together in a known manner. The resulting reduction in diameter acts on the shear plate 2 and compresses it in this area, thus also resulting in the desired compression of the sleeve 1 in this area.

[0023] To prevent the clamping clamp 3 from resting directly on the shear plate, the outer end of the sleeve 1 on the pipe with the smaller outer diameter is first folded over by 180° before the clamping clamp 3 is applied. This allows the end of the shear plate 2 facing the pipe with the smaller outer diameter to be inserted into a pocket 8 formed by folding over the sleeve end. Only then is the clamping clamp 3 applied to the coupling and fastened.

[0024] Figure 1 It also shows a raised edge 7 formed on the cuff, which prevents the shear plate from slipping off the cuff.

[0025] Figure 2 shows a side view of the coupling of Figure 1Here, the clamping screw connection 5 with the clamping band 9 and the worm gear screw as part of the clamping screw connection 5 is clearly shown. The clamping band 9 is riveted to a tab 24 at the end of one side edge of the shear plate 2, while the worm gear screw is attached to the opposite end on the other side edge of the shear plate. The two edges of the shear plate 2 are separated from each other at the parting edge 17. The tab 24 is guided in raised sections 22 and 23 on the opposite part of the shear plate 2 to prevent the tab 24 from tilting.

[0026] Figure 3Figure 1 shows an isolated view of a shear plate 2, illustrating the pressure surfaces 11 formed by the cutouts 4. The cutouts 4 are substantially rectangular, with a constant width along their length. To facilitate bending of the pressure surfaces during the diameter reduction, the pressure surfaces 11 include recesses 12 extending circumferentially around the shear plate, forming defined kinks in the pressure surfaces. The recesses 12 are located in an area immediately adjacent to the shear plate 2's entry into the pocket 8. This allows the pressure surfaces 11 to more advantageously follow the longitudinal axis of the surface of the tube with the smaller outer diameter.

[0027] A further improvement in the adaptation to the pipe surface can be achieved if the pressure surfaces have additional recesses 19 directed in the rotational direction of the shear plate according to Figure 7containing recesses 12 which are formed at a distance from the recesses in the root area of ​​the pressure surfaces, so that when the pressure surfaces are pressed together a graduated progression of the pressure surfaces 11 in the longitudinal direction can be achieved.

[0028] Figure 4 Figure 1 shows a side view of the shear plate 2. The shear plate 2 is divided into two partial shells 15 and 16, which are connected to each other at both edges by clamping screw connections. The division of the shear plate into two parts advantageously prevents the formation of distortions in the sleeve when the clamping screw connections are tightened.

[0029] Figure 4Figure 1 shows that the pressure surfaces 11 do not run in the axial direction of the shear plate, but are inclined at an angle 14 relative to the axial direction. The angle 14 between the axial direction 13 and the edges 20 of the pressure surfaces 11 is preferably 10–60°, more preferably 20–30°, depending on the required diameter adjustment of the tubes. A larger angle has the advantage that the length of the pressure surfaces increases, thus expanding the possible range of diameter reduction. The inclination and increased length of the pressure surfaces 11 also allow for improved adaptation to the surface curvature of the tube with a smaller outer diameter through increased flexibility of the pressure surfaces. A larger angle also allows the width of the cutouts to be reduced while simultaneously increasing the range of diameter adjustment.

[0030] Figure 4This also shows that the pressure surface 21 of the partial shell 15 has a side edge extending in the direction of the parting line 17, while the adjacent side edge of the partial shell 15 runs at an acute angle to it. This has the advantage that the partial shells can be slid against each other without jamming when the pressure surfaces 11 are bent.

[0031] In Figure 5 The partial shells are shown separately. Each contains a tab 24 on one edge, which is guided on the opposite partial shell in upstands 22 and 23.

[0032] Figure 6Figure 1 shows a sectional view of a coupling to illustrate its construction. The sleeve is designed as an elastomeric tube section made of rubber material with internal profiling. In the area of ​​the sleeve where it is attached to the tube with the smaller outer diameter, its end is folded over by 180°, forming a flap 18 that defines a gap which, as a pocket 8, can receive the end of the shear plate 2, which is provided with pressure surfaces. The clamping clamp 3 is attached to the outside of the flap 18. At the end of the shear plate 2, which secures the sleeve to the tube with the larger outer diameter, the shear plate itself has clamping screw connections 5, so that a clamping clamp is not required here.

[0033] In a further embodiment of the invention, the shear plate can also include circumferential profiles similar to a corrugated tube, which allow the coupling to be used to a limited extent for connecting two tubes that are at an angle or slightly offset from each other.

[0034] Finally, especially for temporary use of the coupling instead of clamping screw connections, toggle lever clamping connections can also be used, which allow for easier release of a clamping connection. Reference sign

[0035] 1 Cuff 2 Shear plate 3 Tension clamp 4 Cutout 5 Tension screw connection 6 Tension screw connection 7 Edge bead 8 Pocket 9 Tension band 10 Tension band 11 Pressure surface 12 Recess 13 Axial direction 14 Angle 15 Partial shell 16 Partial shell 17 Dividing edge 18 Flap 19 Recess 20 Edge 21 Pressure surface 22 Upstand 23 Upstand 24 Tab

Claims

1. A pipe coupling for coupling a first pipe with a first larger external diameter and a second pipe with a second smaller external diameter by means of an elastomeric pipe section which connects the pipes and is surrounded by a shear plate (2), wherein the elastomeric pipe section can be fastened by means of the shear plate (2) at its first end to the first pipe and at the second end to the second pipe, wherein the section of the shear plate (2) facing the second pipe is provided with cutouts (4) which separate a series of remaining pressure surfaces (11, 21) of the shear plate (2) from one another and which make it possible, when the second end of the shear plate (2) is fastened to the second pipe, for the pressure surfaces (11, 21) between the cutouts (4) to press the end of the elastomeric pipe section facing the second pipe in such a way that the elastomeric pipe section comes to rest on the second pipe, wherein the shear plate (2) is split in the axial direction along its length, and wherein the shear plate (2), at its end facing the second pipe, clamps the elastomeric pipe section on the second pipe and reduces its diameter when a clamping clip (3) applied to the shear plate (2) is tightened, characterised in that - the shear plate (2), at its end facing the first pipe, can be applied to the external circumference of the elastomeric pipe section and can be reduced in diameter by means of a clamping screw connection (5, 6) fastened to the shear plate, clamping the elastomeric pipe section, and - the cutouts (4) are each aligned obliquely to the axis of the shear plate (2) and are open at the end, wherein the cutouts have a substantially rectangular sectional shape, in which the width of the cutouts remains constant along their length.

2. The pipe coupling according to Claim 1, characterised in that the shear plate (2) is formed from at least two partial shells (15, 16) which are separated in the axial direction and which, at their end of the shear plate (2) facing the pipe with the larger external diameter, can be connected to one another on the external circumference of the elastomeric pipe section by means of a clamping screw connection (5, 6).

3. The pipe coupling according to Claim 1, characterised in that the clamping clip (3) can be applied to the second end of the shear plate (2) via an elastomeric intermediate layer.

4. The pipe coupling according to Claim 3, characterised in that the elastomeric intermediate layer is formed as an end of the elastomeric pipe section, which is turned over by 180°, wherein the end of the shear plate (2) provided with cutouts (4) is received in a pocket (8) at the end of the elastomeric pipe section.

5. The pipe coupling according to Claim 3, characterised in that the elastomeric intermediate layer is fastened to the clamping clip (3).

6. The pipe coupling according to Claim 1, characterised in that the cutouts (4) have a sectional shape which varies in width along their length.

7. The pipe coupling according to Claim 1, characterised in that the elastomeric pipe section has a radially externally directed edge bead (7) at one end at least.

8. The pipe coupling according to Claim 1, characterised in that the pressure surfaces (11, 21) are each provided with one or more recesses (12, 19) in the axially central region of the shear plate (2) outside the end region of the shear plate (2).

9. The pipe coupling according to Claim 6, characterised in that the recesses (12, 19) are configured in an elongated manner in the circumferential direction of the shear plate (2).