EP2313566A1

EP2313566A1 - Sealing member, sliding skin and system comprising such sealing member and sliding skin

Info

Publication number: EP2313566A1
Application number: EP09749505A
Authority: EP
Inventors: Mogens Vilhelmsen
Original assignee: Individual
Current assignee: Ikast Betonvarefabrik AS
Priority date: 2008-05-22
Filing date: 2009-05-15
Publication date: 2011-04-27
Also published as: WO2009140966A1

Abstract

A sealing member for sealing branches of pipes, particularly sewer pipes, a first pipe (1, 1') being inserted into a cylindrical hole (6) provided in the wall of a second pipe (2) with a larger diameter than the diameter of the first pipe (1, 1')- The sealing member (7) comprises a substantially cylindrical body (10) of an elastic material with an outer surface (11) adapted for abutment against the wall of the cylindrical hole (6) formed by the wall of the second pipe (2), and an inner surface (12, 12') adapted for abutment against the outer wall of the first pipe (1, 1'). The inner surface (12, 12') is at least partially shaped substantially like a truncated cone and comprises a toothing (18).

Description

Sealing member, sliding skin and system comprising such sealing member and sliding skin.

The present invention concerns a sealing member for sealing branches of pipes, particularly sewer pipes, a first pipe being inserted into a cylindrical hole provided in the wall of a second pipe with a larger diameter than the diameter of the first pipe, the sealing member comprising a substantially cylindrical body of an elastic material with an outer surface adapted for abutment against the wall of the cylindrical hole which is formed by the wall of the second pipe, and an inner surface adapted for abutment against the outer wall of the first pipe, where the inner surface is at least partially shaped substantially like a truncated cone, the diameter of which i decreases in direction towards the inside of the second pipe when the sealing member is placed in the cylindrical hole in the wall of the second pipe, and where the inner surface comprises a toothing. The invention also concerns a sliding skin for pipes having an irregular outer surface, and a system comprising such sealing member and sliding skin.

EP-A-457319 describes a sealing member of the type mentioned in the introduction. This sealing member is intended for use in cases in which a. first pipe is to be inserted into a bore provided in the wall of a second pipe ^' with a larger diameter. More specifically, this sealing member is intended for a renovation situation, a third pipe being arranged inside the second pipe as the actual pipe in which a branch is to be mounted, the third pipe also having a larger diameter than the first pipe.

According to EP-A-457319, a bore is provided in the walls of the second and third pipes, respectively, the bores having a diameter corresponding to the sealing member. The sealing member is placed in the bores, whereupon the first pipe, the end of which tapers slightly, is pressed entirely through the sealing member so that the tapering end projects on the other side of the sealing member. The tapering end of the first pipe is then cut off inside the third pipe. The cutting-off may be performed manually if space in the third pipe so allows, otherwise a robot can be used.

This sealing member suffers from several disadvantages. Firstly, there is the obvious problem of having to cut off the excess end inside a pipe. Moreover, it is a problem that in order to ensure locking relative to the third pipe the sealing member has to project some distance into the inside of the third pipe, which is undesired, although to some extent permitted, because it restricts the free passage in the pipe. Furthermore, the sealing member is not usable for single-walled pipes with thick walls as the counter-pressure from the entire thickness of the pipe wall, that is, over largely the entire length of the sealing member, will tend to press the first pipe out again due to the inner cone shape of the sealing member, particularly if the first pipe is not pressed completely into the sealing member. Additionally, with the sealing member according to prior art, it will not be possible to ensure sufficient sealing for pipes which are not smooth, for example, pipes with external ribs or corrugations.

Against that background, the object of the present invention is to provide an improved possibility of sealing branches in pipes, particularly sewer pipes, in which a first pipe has been inserted into a cylindrical hole provided in the wall of a second pipe with a larger diameter than the diameter of the first pipe.

According to a first aspect of the invention, this object is obtained through a sealing member of the type mentioned in the introduction, which is characterized in that the substantially cylindrical body comprises at least one extruded member. This makes it possible to provide good engagement between the first pipe and the sealing member so that the pipe is not displaced in the sealing member in an undesired manner or even pressed completely out of it again.

This engagement becomes particularly effective if, according to a second aspect of the invention, the first pipe is provided with a sliding skin of the type mentioned in the introduction, which is characterized in that it comprises an elastic, tubular sleeve intended to be pulled over at least part of the pipe so as to cover the outer surface in the area of the relevant one of the ends of the pipe, and in that the surface of the sleeve intended to face away from the irregular outer surface of the pipe comprises a toothing.

This makes it possible to ensure better engagement as the toothing can engage with the toothing on the sealing member in substantially shape-locking engagement.

As a further advantage, the structure of the sealing member generally has the effect that a smaller deforming and/or mounting force and a more variable deforming force are required than has been known before, and a seal of the pipes is thereby achieved by the use of a compact, homogenous and flexible sealing member with a definable IRHD or Shore hardness.

Additionally, the elasticity of the sliding skin makes it contract at the relevant pipe end to a smaller diameter than the external diameter of the pipe. Firstly, this protects the sealing member against any sharp edges at the pipe end that might damage the sealing member. Secondly, it has the effect of sealing in front of and along the pipe if the latter does not have a smooth surface, but is provided with, for example, external annular ribs or corrugations.

In a preferred embodiment of the sealing member according to the invention, at least one projection has been provided on the inner surface in the area of the end closest to the inside of the second pipe when the sealing member is placed in the cylindrical hole in the wall of the second pipe. Thereby, this internal projection acts as a stop and in a simple manner prevents the first pipe from being inserted, too far into the second pipe, thus projecting an undesired distance into it as described above.

In a further preferred embodiment of the sealing member according to the invention, at least one projection has been provided on the outer surface in the area of the end farthest away from the inside of the second pipe when the sealing member is placed in the cylindrical hole in the wall of the second pipe. This acts as an external stop and prevents the actual sealing member from being pressed too far into the second pipe.

In a particularly preferred embodiment of the sealing member according to the invention, at least one projection is made of a material, the elasticity of which differs from the elasticity of the elastic material of which the substantially cylindrical body is made. In this way, the projections, which are not intended to have any sealing effect, can be made of a harder material and thereby better fulfil their function as stops.

In yet a preferred embodiment of the sealing member according to the invention, the inner surface furthermore comprises a substantially cylindrical surface. A cylindrical surface allows the inserted first pipe to be angled slightly relative to the axis of the hole without thereby compromising the seal.

In yet a preferred embodiment of the sealing member according to the invention, the tips of the teeth of the toothing have a mutual spacing of between 1 mm and 5 mm, preferably approx. 2 mm. Experiments have shown that these dimensions ensure good locking and a good seal.

In a further preferred embodiment of the sealing member according to the invention, the height of the teeth of the toothing is between 0.2 mm and 5 mm, preferably approx. 1 mm. Experiments have shown that these dimensions ensure good locking and a good seal.

In yet a further embodiment of the sealing member according to the invention, the cross-section of the teeth is asymmetrical, and the angle of the longest flank is between 5° and 25°, preferably approx. 15°, relative to the longitudinal axis of the sealing member. This ensures easy insertion of the first pipe and properly ensures its position in the sealing member.

In yet another preferred embodiment of the sealing member according to the invention, the cylindrical body comprises at least one annular cavity. Introducing an annular cavity in the material of the sealing member, in particular in the vicinity of the open ends of the sealing member, prevents the sealing member from flaring out, i.e. having an undesired increasing diameter towards the openings, due to the elastic properties of the material.

Concerning the sliding skin according to the second aspect of the invention, it is in a preferred embodiment of the invention designed so that the surface of the sleeve intended to face away from the outer surface of the pipe is at least partially shaped substantially like a truncated cone, the diameter of which, when the sliding skin is pulled over the pipe, decreases in a direction towards the relevant end of the pipe. This ensures uniform abutment against the inner cone shape of the sealing member so that a uniform and controlled pressure is built up and the seal is ensured along the entire length of the sealing member. This furthermore helps ensure the position of the sliding skin relative to the sealing member.

In yet a preferred embodiment of the sliding skin according to the invention, the surface of the sleeve intended to face the outer surface of the pipe is provided with irregularities intended to correspond to an irregular outer surface of the pipe. Not only does this ensure a more uniform and well-defined pressure against the sealing member, the seal towards the first pipe is also further improved.

According to a further preferred embodiment of the sliding skin according to the invention, it has a toothing corresponding to that of the sealing member, which means that the tips of the teeth of the toothing have a mutual spacing of between 1 mm and 5 mm, preferably approx. 2 mm, that the height of the teeth of the toothing is between 0.2 mm and 5 mm, preferably approx. 1 mm, that the cross-section of the teeth is asymmetrical, and that the angle of the longest flank is between 5° and 25°, preferably approx. 15°, relative to the longitudinal axis of the sealing member.

The invention will now be described in more detail below by means of a number of non-limiting examples of embodiments and with reference to the drawing, on which

Fig. 1 schematically shows a partial cross-section through a system according to the invention, in which the upper part of the Figure shows an example with a first sliding skin on a corrugated pipe, and the lower part shows an example with a second sliding skin on a pipe with external ribs;

Fig. 2 shows a sealing member corresponding to that shown in Fig- 1;

Fig. 3 shows a sliding skin corresponding to the embodiment shown at the top of Fig. 1;

Fig. 4 shows an alternative embodiment of the sealing member of Fig. 2;

Fig. 5 shows yet an alternative embodiment of the sealing member of Fig. 2;

Fig. 6 shows a sealing member with examples of general toothings; and Fig. 7 shows how the sealing member can be used in bores with a non-intended diameter.

Fig. 1 schematically shows a cross-section through a system according to the invention during the mounting of a first pipe 1, 1' in a second pipe 2. Fig. 1 is in two parts illustrating different shapes of the first pipe. The second pipe 2 comprises a pipe wall surrounding the inside 3 of the pipe and defining an inner surface 4 of the pipe 2 and an outer surface 5 of the pipe 2. A passage has been provided in the second pipe 2 between the outer surface 5 and the inner surface 4. The passage is typically a cylindrical, radial bore 6 at right angles to the longitudinal axis of the second pipe 2, but the passage might also be pre-fabricated.

Despite the fact that the pipe wall of the second pipe 2 is shown in the

Figures as a solid pipe, a worker skilled in the art will understand that the wall of the second pipe 2 need not be solid, but might, for example, comprise slat profiles formed and integrated into a sandwich structure. A sealing member 7 according to the invention into which the first pipe 1, 1' is to be inserted has been fitted in the bore 6. To illustrate that the invention can be used with different types of pipes, the first pipe

1, 1' is shown partly as a pipe 1 with a corrugated outer surface, and partly as a pipe with an outer surface with annular ribs. Moreover, Fig. 1 shows the two alternatives of the first pipe 1, 1' in different positions during the mounting, as the corrugated pipe is seen to have been inserted slightly further into the sealing member 7.

Fig. 1 also shows how a sliding skin 8, 8' according to the invention has been provided between the sealing member 7 and the first pipe 1, 1' to be inserted therein.

Finally, Fig. 1 illustrates that filling members 9, 9' may be disposed around the pipe 1, 1' and may, at least under pressure, correspond to the irregularities of the surface structure, thereby filling them out. Such filling members 9, 9' might be arranged between the sliding skin 8, 8' and the first pipe 1, 1'.

The sealing member 7 of Fig. 1 is shown in more detail in Fig. 2. Fig. 2 shows how the sealing member 7 comprises a substantially cylindrical body 10 made of an elastic material, such as rubber, having in its natural shape a substantially cylindrical outer surface 11 and an inner surface 12 at least partially shaped substantially like a truncated cone so as to provide a through-going, substantially conical aperture 13. In this connection, natural shape means the shape of the sealing member when not elastically deformed by external forces. The substantially conical opening tapers towards a first end 14, which, as appears from Fig. 1, is intended for positioning at the inner surface 4 of the second pipe 2 when the sealing member 7 is mounted in the wall thereof.

In the area of the first end 14 of the sealing member 7, in the illustrated case more specifically directly in connection with the first end 14, at least one projection 15 is provided on the inner surface 12. This projection 15 acts as an end stop and prevents the first pipe 1, 1' from being pressed too far into the second pipe 2 during mounting. As shown, a single annular projection 15 may be provided, or one or more individual projections 15 may be provided. The projection 15 may be made of a material with higher hardness and lower elasticity than the elastic material of which the body 10 is generally made, so that the function as an end stop is improved compared with a situation in which the end stop is made of the same material as the rest of the body 10.

In the area of the other or second end 16 of the sealing member 7, at least one projection 17 is provided on the outer surface 11. This projection 17 acts as a stop and prevents the sealing member 7 from being pressed too far into the second pipe 2 during mounting. As shown, a single annular projection 17 may be provided, or one or more individual projections 17 may be provided. The projection 17 may be made of a material with higher hardness and lower elasticity than the elastic material of which the body 10 is generally made, so that the function as a stop is improved compared with the situation in which the stop is made of the same material as the rest of the body 10. As illustrated, the projection is not necessarily mounted directly at the second end 16 of the sealing member 7, but is retracted slightly along the outer surface 11. This provides a surface part 11a which, at mounting, projects past the outer surface 5 of the second pipe 2 and surrounds the first pipe 1,1'. If necessary, this surface may advantageously be used for mounting a supplementary fastening of the pipe 1,1' relative to the sealing member 7, for example in the form of a clamping strap (not shown). However, this is only a supplementary fastening as the sealing member 7 according to the invention ensures its position itself relative to the pipe 1,1', as mentioned above and as will appear later.

To secure the sealing member 7 and the pipe 1 relative to each other, a toothing, preferably in the shape of a number of annular teeth 18, has been provided on the inner surface 12. The dimensions of the teeth 18 have preferably been chosen so that the teeth are pressed substantially completely flat or down, at least when a first pipe with a smooth outer surface is pressed into the sealing member. No clearance is thus left as would be the case with lip seals, and the sealing member 7 thereby effectively prevents undesired water penetration between the first pipe 1 and the sealing member 7. More specifically, it has proved that this is obtained if the tips of two neighbouring teeth 18 of the toothing have a mutual spacing of between 1 mm and 5 mm, preferably approx. 2 mm, and the height of the teeth of the toothing is between 0.2 mm and 5 mm, preferably approx. 1 mm. Preferably, the cross-section of the teeth is also asymmetrical, and the angle of the longest flank is between 5° and 25°, preferably approx. 15°, relative to the longitudinal axis of the sealing member. The result is that the teeth are easily pressed down and that they have a good effect as barbs relative to the first pipe 1, 1'.

To ensure good engagement with the wall of the bore 6 in the second pipe 2, one or more toothings 19 with the dimensions may be provided on the outer surface of the sealing member 7. However, this is less critical as the outer surface 11 of the sealing member 7 is cylindrical like the bore 6. When the elastic material of the sealing member 7 is compressed because a first pipe 1 has been pressed into the sealing member 7, the forces from the sealing member 7 will therefore mainly act radially, for which reason the sealing member 7 will only have a limited tendency to become displaced relative to the bore 6.

Whether or not such outer toothing 19 is present, it is advantageous, however, if the outer surface 11 is substantially cylindrical over the entire length of the sealing member 7. This allows for close contact with the entire surface of the bore 6, thus preventing any water penetration to any reinforcing iron possibly uncovered when the bore 6 was provided. Fig. 4 shows an alternative embodiment of the sealing member according to the invention. The same reference numerals have been used for those parts that do not differ from the embodiment shown in Fig. 2, and the description of those parts will not be repeated. Thus, in the area of the second end 16 of the sealing member 7, at least one projection 17' is provided on the outer surface 11. This projection 17' acts as a stop and ensures that the sealing member 7 is placed in the correct position. As shown, a single annular projection 17' may be provided, or one or more individual projections 17' may be provided. The projection 17' may be made of a material with higher hardness and lower elasticity than the elastic material of which the body 10 is generally made, so that the function as a stop is improved compared with the situation in which the stop is made of the same material as the rest of the body 10. Compared with the embodiment shown in Fig. 2, in which the stop 17 prevents the sealing member 7 from being pressed too far into the second pipe 2, the stop 17' has the opposite effect. Here, the sealing member 7 is placed in the bore 6 by first folding it together and then inserting it so far through the bore 6 that the stop is located inside the pipe 2. The sealing member 7 then automatically unfolds when released and can subsequently be pulled backwards until the stop 17' abuts against the inner wall 4 of the pipe 2 at the desired correct position. At correctly chosen dimensions of the sealing member 7 and the bore 6, the forces between the outer surface 11 and the wall of the bore 6 are sufficient to retain the sealing member 7 in the desired position, also while the first pipe 1, 1' is subsequently pressed into the sealing member.

Although the design of the sealing member 7 may be sufficient to ensure both the seal and the retention of the first pipe 1 in case of smooth pipes and pipes 1, 1' with an irregular outer surface, it may be advantageous, however, to improve it further. Now referring to Fig. 3, a sliding skin 8 has thus also been provided according to the invention, together with the sealing member 7 constituting a system for sealing pipe branches. The sliding skin 8 comprises a tubular sleeve 21 made of an elastic material with a uniform inside circumference along the entire length when the sleeve has its natural shape, that is, when it is not elastically deformed by external forces. To facilitate the description, it is assumed in the following that no external forces, not even gravity, act upon the sliding skin 8, which thus has an inner, substantially cylindrical surface 22. The outer surface 23 may also have a substantially cylindrical shape, but is preferably shaped like a truncated cone and is accordingly conical, particularly with a cone shape corresponding to the inner surface 12 of a sealing member 7 such as best seen in the upper half of Fig. 1. In this way, a substantially uniform pressure arises between the respective surfaces 12 and 23 of the sealing member 7 and the sliding skin 8.

As best seen from Fig. 3, the outer, substantially conical surface is provided with a toothing with annular teeth 24. Preferably, these are complementary to the teeth 18 of a sealing member 7 with which the sliding skin 8 is to cooperate as a system. Thereby, the teeth 18 and 24 of the respective toothings may lockingly engage with each other with simultaneous deformation and friction locking.

As further seen from Fig. 1, the sliding skin 8, 8' will contract in front of the first pipe as seen in the pressing-in direction when a suitable dimension has been chosen. This provides several advantages. Firstly, it will thus cover any sharp edges and burrs at the pipe end, thereby preventing any damage to the sealing member 7. Such sharp edges and burrs may be considerable in case of concrete pipes and not, for example, PVC pipes, particularly in case of a cut concrete pipe and not just a concrete pipe with a pre-fabricated spigot end. Secondly, it effectively closes off any openings that may exist with a pipe with an irregular surface, for example the two pipes shown in Fig. 1 with ribs and corrugations, respectively, or the concrete pipes mentioned above. The seal is thereby increased as penetration of water to the first cavity formed by the irregularities is thereby prevented. As the sliding skin 8, 8' also covers and seals the subsequent cavities, any farther penetration of water is additionally prevented.

To further prevent any such penetration of water, the inner, substantially cylindrical surface 22 may be provided with projections corresponding to the cavities formed by the irregularities between peaks and troughs of the corrugation instead of being smooth as shown in Fig. 3.

Fig. 5 shows yet an embodiment of a sealing member 7 according to the invention. In this sealing member 7, the inner surface 12 comprises not only a surface shaped substantially like a truncated cone, but also a substantially cylindrical surface 12' of a length d at the inner end of the sealing member 7 adjacent to the projection 15. Like the remainder of the inner surface, this substantially cylindrical surface 12' comprises a toothing 18. The cylindrical surface 12' allows the insertion of a pipe 1, 1' at a slight angle relative to the longitudinal axis of the sealing member 7 without causing any leaks. Further to Fig. 5, it should be noted that this embodiment has no external projections. The internal and external projections 15, 17, 17' are optional, and a worker skilled in the art will understand that the use thereof and their location can therefore freely be combined from the different embodiments shown, and they can also have other suitable locations.

Of course, the dimensions of the sealing member 7 according to the invention depend on the dimensions of the pipes with which it is to be used as the cross-sectional profile of the wall of the substantially cylindrical body 10 may be the same for quite a number of dimensions of the first pipe with which it is to be used. This means that the external and internal diameters of the sealing member 7 may vary depending on the external diameter of the first pipe 1, 1', for which it is intended, without any deviation of the profile of the wall of the various sealing members 7.

One advantage of this is that different sealing members 7 may be manufactured from one and the same extruded profile, which is then cut off at a desired length, and the two ends are joined together, for example by gluing or vulcanisation, into a substantially cylindrical sealing member with the desired diameter. This need not necessarily be carried out at the manufacture, but may be carried out on site, if required. It is possible to imagine that a suitable length of a profile is cut off on site and joined together, or that a suitable piece of a pre- fabricated sealing member 7 with a larger diameter is cut out, whereupon the free ends are joined together into a new sealing member 7 with a smaller diameter. Extrusion offers the further advantage that it becomes quite easy, compared with, for example, moulded sealing members, to provide the projections 15, 17, 17' on the respective outer and inner surfaces 11 and 12. One particular advantage is that it is possible not only to extrude homogenous profiles, but that the projections 15, 17, 17' can be given a different hardness through co- extrusion in another material than the cylindrical body 10 in general so that their function as a stop is improved. Moreover, annular cavities 28 may be provided.

Such annular cavities 28 have found to be advantageous in mitigating one drawback arising from forming the sealing member 7 from an extruded profile in the way described above. This drawback being that, the forces introduced in the sealing member 7 when forming a cylindrical body from an otherwise straight elongated member, will cause the end portions at the first end 14 and the second end 16 of the essentially cylindrical body to flare out. The overall external diameter of the essentially cylindrical outer surface 11 of the sealing member 7 will thus increase slightly towards the openings at the first end 14 and the second end 16. This flaring out is undesired as it hinders the introduction of in particular the first end 14 into the radial bore 6. To overcome this drawback, annular cavities 28 have been provided in the vicinity of both the first end 14 and the second end 16, where they influence the internal forces in the elastic material and hinders or at least substantially reduces the flaring out of the first end 14 and the second end 16. Though the annular cavities 28 are a preferred embodiment, the do remain an option, and it the skilled person will appreciate that they need not be present at both the first end 14 and the second end 16. The skilled person will also understand that more than one annular cavity 28 may provided at either of both the first end 14 and the second end 16, as well as in other places throughout the sealing member 7.

For the sealing member 7 shown in Fig. 5 for use with a first pipe with an external diameter of 70 mm, but as mentioned above also other diameters, typical dimensions could be a wall thickness of 14 mm at the cylindrical surface part 12' and a wall thickness of 12 mm at the end surface at the second end 16, a tooth height of the inner toothing 18 of 1 mm in addition to the said wall thicknesses, a tooth pitch of 2 mm, a total length of the sealing member of 150 mm, a length of the substantially cylindrical surface of 20 mm, and a height and length of the projection 15 of approx. 3 mm.

Concerning the dimensions, it should also be mentioned that experiments have shown that the sealing member 7 according to the invention can be used even where the second pipe 2 has a wall thickness as small as 20 mm, provided that the curvature, that is, in practice, the diameter of the second pipe 2, does not prevent it generally for other reasons.

Fig. 6 shows a sealing member 7 with several inner surfaces 12', 12", 12"' shaped substantially like truncated cones provided with toothings 18. These surfaces 12', 12", 12'" shaped like truncated cones constitute a form of general toothing. They are adapted to be of differing hardness, undercuts 25 being provided in one flank. The undercuts 25 may have differing dimensions, and material 26, 26' of differing shapes and hardness may be arranged or embedded therein. For illustrative purposes, Fig. 6 shows several different varieties in one and the same sealing member 7, but in practice the dimensions of the undercuts, of the material arranged or embedded therein and the hardness thereof will typically be the same for all the teeth of the general toothing. If the material 26, 26' is embedded, it may be co-extruded with the rest of the profile. Alternatively, the material 26, 26' may be moulded in or arranged therein as loose parts. Material 26, 26' which is either harder or softer than the material of the body 10 in general may thus be arranged or embedded therein. Fig. 7 shows a situation in which the radial bore 6 has a larger diameter than desired, for example, because a drill head with too large a diameter was chosen for the drilling process by mistake. Fig. 7 shows that, as an alternative to the cutting and adaptation of the sealing member 7 mentioned above or to the dedicated manufacture thereof, it is possible to insert suitable supplementary packing 27, 27'. Fig. 7 also shows that it is possible, by a process corresponding to the cutting and gluing together or vulcanisation mentioned above, to provide a member with both a conical outer surface and a conical inner surface. It is merely necessary to cut a suitable wedge-shaped portion out of the profile. This furthermore allows the use of a smaller first pipe 1, I¹ than originally intended. Of course, it is also possible to pre-fabricate a sealing member with both a conical outer surface and a conical inner surface, and in that case the outer surface may have a toothing with teeth adapted for shape-locking engagement with the toothing 18 of the sealing member 7.

Finally, it should be noted that the embodiments described are only examples, and that the illustrations are schematic. A person skilled in the art will therefore understand that innumerable other varieties may be imagined without deviating from the invention. As an example, the ends of the sealing member 7 and correspondingly the location of the projections 15, 17, 17' could be adapted so that they match the inner and/or outer curvature of the second pipe instead of simply being cut off at right angles to the longitudinal axis of the sealing member 7 as shown schematically. Of course, this would render the manufacture by extrusion difficult, but it should be noted that the sealing member 7 is not limited to being manufactured by that method; it might just as well be manufactured by moulding, for example. As a further variation the inner surface may include circumferential grooves with e.g. a part- circular cross-section for locating additional sealing members such as o- rings.

It would also be possible to use the sealing member 7 in a pipe socket without deviating from the principles of the invention. This could be done, for example, by casting of the hole around a profile ring so that it acts as a conventional sealing system in a pipe/well system made of, for example, concrete.

Claims

C L A I M S

1. A sealing member for sealing branches of pipes, particularly sewer pipes, a first pipe being inserted into a cylindrical hole provided in the wall of a second pipe with a larger diameter than the diameter of the first pipe, the sealing member comprising a substantially cylindrical body of an elastic material with an outer surface adapted for abutment against the wall of the cylindrical hole formed by the wall of the second pipe, and an inner surface adapted for abutment against the outer wall of the first pipe, where the inner surface is at least partially shaped substantially like a truncated cone, the diameter of which decreases in a direction towards the inside of the second pipe when the sealing member is placed in the cylindrical hole in the wall of the second pipe, and where the second surface comprises a toothing, c h a ra cte r i z e d in that, the substantially cylindrical body comprises at least one extruded member.

2. A sealing member according to claim 1, c h a ra cte ri ze d in that the surface shaped substantially like a truncated cone is designed so that the.

3. A sealing member according to claim I or2, c h a ra cte r i z e d in that at least one projection has been provided on the inner surface in the area of the end closest to the inside of the second pipe when the sealing member is placed in the cylindrical hole in the wall of the second pipe.

4. A sealing member according to any one of claims 1 to 3, c h a ra cte ri ze d in that at least one projection has been provided on the outer surface in the area of the end farthest away from the inside of the second pipe when the sealing member is placed in the cylindrical hole in the wall of the second pipe.

5. A sealing member according to any one of claims 3 or 4, c h a ra cte ri zed in that at least one projection is made of a material, the elasticity of which differs from the elasticity of the elastic material of which the substantially cylindrical body is made.

6. A sealing member according to any one of the preceding claims, c h a ra cte ri ze d in that the inner surface furthermore comprises a substantially cylindrical surface.

7. A sealing member according to any one of the preceding claims, c h a ra cte ri ze d in that the tips of the teeth of the toothing have a mutual spacing of between 1 mm and 5 mm, preferably approx.2 mm.

8. A sealing member according to any one of the preceding claims, c h a ra cte ri z e d in that the height of the teeth of the toothing is between 0.2 mm and 5 mm, preferably approx. 1 mm.

9. A sealing member according to any one of the preceding claims, c h a ra cte ri ze d in that the cross-section of the teeth is asymmetrical, and that the angle of the longest flank is between 5° and 25°, preferably approx. 15°, relative to the longitudinal axis of the sealing member.

10. A sealing member according to any one of the preceding claims, c h a ra cte ri ze d in that the cylindrical body comprises at least one annular cavity.

11. A sliding skin for fitting on the outer surface of pipes, particularly pipes with an irregular outer surface, c h a ra cte ri z e d in that it comprises an elastic, tubular sleeve intended to be pulled over at least part of the pipe so as to cover the outer surface thereof in the area of a relevant one of the ends of the pipe, and in that the surface of the sleeve intended to face away from the irregular outer surface of the pipe comprises a toothing.

12. A sliding skin according to claim 11, c h a ra cte r i z e d in that the surface of the sleeve intended to face away from the outer surface of the pipe is at least partially shaped substantially like a truncated cone, the diameter of which, when the sliding skin is pulled over the pipe, decreases in a direction towards the relevant end of the pipe.

13. A sliding skin according to any one of claims 11 or 12, c h a ra cte ri z e d in that the surface of the sleeve intended to face the outer surface of the pipe is provided with irregularities intended to correspond to an irregular outer surface of the pipe.

14. A sliding skin according to any one of claims 11 to 13, c h a ra cte ri ze d in that the tips of the teeth of the toothing have a mutual spacing of between 1 mm and 5 mm, preferably approx.2 mm.

15. A sliding skin according to any one of claims 11 to 14, c h a ra cte ri zed in that the height of the teeth of the toothing is between 0.2 mm and 5 mm, preferably approx. 1 mm.

16. A sliding skin according to any one of claims 11 to 15, c h a ra cte ri zed in that the cross-section of the teeth is asymmetrical, and that the angle of the longest flank is between 5° and 25°, preferably approx. 15°, relative to the longitudinal axis of the sealing member.

17. A system for sealing branches of pipes, c h a ra cte ri ze d in that it comprises a sealing member according to any one of claims 1 to 10 and a sliding skin according to any one of claims 11 to 16.