The present invention relates to a device for connecting a pipe to a hollow body with a plastic wall, in particular to a deformed pipe liner part with a plastic wall, comprising a feed-through pipe which can be inserted into an opening in the wall of the body, a sealing part which has a side for pressing against the outside of the wall of the body, and fastening means for fixing the feed- through pipe in a sealing manner relative to the body.

Such a device is generally known and comprises a metal feed-through pipe to which an outward projecting flange is welded. A flexible rubber sealing ring is placed between the flange and the outside of the wall of the body. The sealing ring is compressed and a seal is obtained by pulling the flange towards the hollow body using clamping means.

The known device has the disadvantage that a reliable seal is not obtained in all situations with the flexible sealing ring.

The problem of an insufficiently reliable seal occurs in particular during the lining of a pipe, for example a concrete sewer pipe, using a deformed pipe liner part with a wall of thermoplastic material. In this case the pipe liner part, which has, for example, a C-shaped cross-section, is pulled into the sewer pipe. Steam is then fed into the pipe liner part, which is shut off at the ends, with the result that the pipe liner part returns to its undeformed cylindrical shape and comes to rest against the inside of the sewer pipe. As a result of pulling the pipe liner part into the sewer pipe, the outside of the wall thereof will have sustained damage in the form of scratches and grooves. After the pipe liner part has been pulled in, when one or more connections are installed for supplying steam and/or discharging the condensation formed, a sufficiently reliable seal cannot be obtained with the known device.

The invention also relates to a method for connecting a pipe to a hollow body with a plastic wall, in particular to a deformed pipe liner part with a plastic wall for lining a pipe, for example a sewer pipe. The object of the invention is to eliminate the above entioned disadvantages and to provide a simple device which can be installed reliably for the connection of a pipe, and also a method for making a connection.

This object is achieved by a device of the type mentioned in the preamble, which is characterized in that the sealing part is a part made of a rigid material which is provided with a bore through which the feed-through pipe can project in a sealing manner, and which at its side for pressing against the outside of the wall of the body has a projecting annular wall lying all round the bore for the feed-through pipe, the annular wall forming a penetration edge which can penetrate into the plastic wall of the body. It is clear that the feed-through pipe in this case can be a connecting piece between the hollow body and the pipe to be connected thereto, but that the feed-through pipe can also be formed by the end of the pipe to be connected. The penetrating action of the annular wall of the sealing part into the plastic wall of the hollow body produces a very reliable seal. The penetration depth of the annular wall means that any grooves or other damage to the outside of the wall do not affect the seal to be achieved. It is clear that the plastic wall of the body must have a thickness which, on the one hand, allows the annular wall to penetrate a penetration depth into it and, on the other, ensures that, when the annular wall is pressed against the wall, the wall produces such resistance that the annular wall penetrates into the wall, and the wall does not just bend inwards with it. A further advantage of the penetration depth of the annular wall is that the sealing part does not have to be accurately adapted to the measurements of the hollow body, for example to the diameter of a plastic pipe. Finally, the penetrating action permits simple fitting of the device.

In a preferred embodiment, the annular wall extends

coaxially with the bore for the feed-through pipe, the outer face of the annular wall is essentially cylindrical, and the inner face of the annular wall is a part of a conical face running inwards from the free edge. This shape of at least the part of the annular wall penetrating into the plastic wall produces a seal which is resistant to high pressures and high temperatures. The outer face and the inner face of the annular wall in this case advantageously form an angle of approximately 10°. The annular wall is advantageously provided at its free edge with two adjoining bevelled edges, for example forming an angle of 60° between them. This shape of the free edge of the annular wall to be placed against the wall of the hollow body facilitates the penetration of the annular wall into the wall of the hollow body.

In a specific embodiment, the sealing part is a ring shut off by a transverse face, the transverse face being provided with the bore for the feed-through element. In another preferred embodiment, the sealing part is a metal part. The sealing part could, however, be made of a fibre-reinforced plastic or a similar material.

If the sealing part is a metal part, the feed- through element is advantageously a metal pipe part, and the sealing part is welded to it. This means that the assembly of feed-through element and sealing part can easily be fitted in one piece when a connection for a pipe is being produced.

When a part of the feed-through element projecting through the wall is provided with ribs and grooves on the outside, an additional sealing effect is obtained between the feed-through element and the wall of the body if the opening therein is matched to the size of the feed-through element.

In a further embodiment, the fastening means comprise a first bush, an annular element to be fitted around the body for fixing the first bush around the opening disposed in the wall of the body, and a second bush to be screwed onto the first bush, the second bush pressing the sealing part placed inside the first bush against the

- A - wall of the body.

The invention also provides a method for connecting a pipe to a hollow body with a plastic wall, in particular to a deformed pipe liner part with a plastic wall for lining a pipe, for example a sewer pipe, which is characterized in that the wall of the hollow body is provided with an opening, in that a feed-through element is inserted into the opening, and in that a metal sealing part through which the feed-through element can project in a sealing manner is placed against the wall of the hollow body and a force directed towards the wall of the hollow body is exerted, in such a way that an annular wall of the sealing part penetrates a predetermined penetration depth into the wall of the hollow body, and the sealing part is fixed in that position. With this method, apart from making an opening in the wall of the hollow body, no additional actions such as repairing damage in the wall need be performed for obtaining a reliable seal.

The invention will be explained in greater detail below with reference to the appended drawing, in which: Fig. 1 shows diagrammatically a detail of the fitting of a deformed pipe liner part in a sewer pipe, in which an example of an embodiment of the device according to the invention and of the method according to the inven- tion are used;

Fig. 2 shows a section in the plane of the device according to the invention in Fig. 1; and

Fig. 3 shows a section of the sealing ring in Fig. 2. Fig. 1 shows a pipe liner part 2 of thermoplastic material placed in a pipe 1 which is to be lined, in this example a concrete sewer pipe. The pipe liner part illustrated in the deformed state has an essentially C-shaped cross-section, while its original undeformed state is cylindrical. The front end of the pipe liner part is provided with a plastic sealing element 3. The sealing element 3 comprises a flat plastic plate 5 with two passages 6 and a thick-walled cylindrical pipe part 7 of thermoplastic material welded to the flat plate. A

hemispherical plastic end cap 8 with a pulling eye 9 is welded to the front side. The pulling eye 9 serves for the fastening of a pull-in cable for pulling the pipe liner part into the sewer pipe. After the pipe liner part 2 has been pulled into the sewer pipe 1 using suitable means, a device 10 for the connection of a condensation discharge pipe is fitted on the cylindrical pipe part 7. For this purpose, the end of the pipe liner part shown in Fig. 1 is then situated in a readily accessible place, for example in a well. A heating and pressure medium source is then connected to a passage opening in a shut-off element (not shown) at the other end of the pipe liner part.

In the case of the method for fitting the pipe liner part 2 taut against the inside of the sewer pipe 1, a heating and pressure medium, for example steam, is supplied to the inside of the pipe liner part 2 which is then still in its state deformed to a C-shape. The temperature of the plastic wall of the pipe liner part rises as a result, and a pressure is exerted on the pipe liner part. As a result of the rise in the temperature of the wall, the shape memory of the thermoplastic material of the pipe liner part, assisted by the pressure, causes the pipe liner part 2 to return virtually to its original cylindrical cross- section. Fig. 2 shows the device 10 when fitted. The device

10 comprises a metal feed-through pipe 11 which is inserted through a bore disposed in the wall of the cylindrical part 7. A metal sealing ring 12, which penetrates a penetration depth into the plastic wall of the cylindrical pipe part 7 when the connection is being made, is welded to the feed- through pipe 11. This produces a reliable seal, even if the cylindrical part 7 is damaged in the process of being pulled in. The sealing ring 12 will be explained in greater detail with reference to Fig. 3. For fitting the feed-through pipe in a sealing manner, a ring 13, provided with a first metal bush 14 with internal screw thread, is placed around the cylindrical pipe part 7. The feed-through pipe 11 is then inserted into the opening, in which case the sealing ring 12 welded to

the feed-through pipe 11 comes to rest inside the first bush 14. If an externally threaded second bush 15 is then screwed into the first bush 14, the metal annular wall of the sealing ring 12 is pressed against the plastic and will penetrate a certain penetration depth into the plastic. A very reliable sealing closure is thus obtained in a simple way.

An additional sealing action is obtained through the fact that the feed-through pipe 11 is provided with grooves and ribs 16 which engage in a sealing manner on the wall of the bore in the cylindrical part 7. As a result of the shape of the part of the annular wall of the sealing ring 12 penetrating into the plastic wall, the opening in the wall is compressed, and a clamping between said wall and the feed-through pipe 11 is produced.

Fig. 3 shows in greater detail the embodiment of the metal sealing ring 12 shown in Fig. 2. The sealing ring 12 comprises a transverse face 20 in which a bore 21 for the feed-through pipe 11 is provided. The sealing ring 12 also has an annular wall 22 forming a penetrating edge which penetrates into the plastic wall. The outer face 23 of the annular wall 22 is cylindrical, while the inner face 24 is a part of a conical face running from the free edge inwards. The outer face 23 and the inner face 24 in this case form an angle of approximately 10°.

In order to make it easier to press into the wall, the annular wall 22 is provided at its free edge with two adjoining bevelled edges 25, 26, which form an angle of 60° between them. It is clear that the device according to the invention can be designed in many different ways and can be used in many situations in addition to the method described here. These are in particular situations in which a temporary connection facility must be provided, since in such a situation the possible weakening of the plastic wall through the metal annular wall penetrating it has little • negative effect on the load-bearing capacity of the plastic wall. For example, in an embodiment not shown the feed- through pipe could be provided with external screw thread,

by means of which the feed-through pipe could be screwed firmly into the plastic wall. A reliable seal is then obtained again through the fact that the annular wall connected in a sealing manner to the feed-through pipe cuts into the wall. The free edge of the annular wall could also be provided with a sort of toothing, instead of bevelled edges, in order to promote penetration or cutting of the annular wall into the plastic wall.