FIELD OF THE INVENTION

The present invention relates to a pipe seal for sealing between a first pipe and a second pipe, in particular between a first corrugated pipe and a second corrugated pipe. The invention also relates to a corresponding sealing system.

BACKGROUND OF THE INVENTION

Corrugated pipes are available in a wide range of diameters and are commonly used for sewer and storm water applications. To assemble two corrugated pipes with each other a spigot of a first pipe is slid into a socket of a second pipe. To seal the joint assembly, it is known to use a rubber sealing generally placed inside a groove of the spigot pipe.

Such a rubber sealing for sealing between two corrugated pipes is disclosed by DE 102016 106 116 A1 . The rubber sealing is first mounted in a spigot groove. Then the spigot pipe is slid into the socket pipe, thus compressing the sealing lip. When the pipes are assembled, the rubber sealing element is designed to deform. This creates pressure on both spigot and socket, ensuring a watertight sealing. This type of seal is designed to fit with a single defined diameter of the spigot groove.

A further pipe seal is disclosed by US 2010/0140925 A1. The pipe seal is placed in a groove of a pipe. To hold the seal in place a reinforcing means is used to hold the seal inside the groove.

For achieving a good sealing performance for a range of diameters of pipe systems, it is necessary that the seal allows to fit with different pipe systems and to still provide a watertight seal. However, during the insertion of the second pipe into the first pipe, in particular for small diameters of pipes, there is the risk that the seal is dislocated such that the sealing performance is deteriorated or completely destroyed.

SUMMARY OF THE INVENTION

Hence, it is an object of the present invention to provide a pipe seal and a sealing system which can be used for many different designed corrugated pipes and which have an improved sealing performance.

The above object is solved by a pipe seal according to claim 1 and a sealing system according to claim 13. The dependent claims describe preferred embodiments of the invention.

According to the invention a pipe seal is provided for sealing between a first pipe and a second pipe having at least one depression and at least one elevation. The pipe seal comprising an annular sealing member made of an incompressible material and configured to be positioned on the elevation of the second pipe; at least one retainer element connected to the sealing member and extending partially along the circumference of the sealing member. The retainer element is configured to engage with the depression for holding the annular sealing member in place when coupling the first pipe with the second pipe.

An advantage of the pipe seal is that it can be used with pipes of different designs of corrugations and a variety of diameters. In particular, as the sealing member is designed to be supported by the elevation and held in place during assembly by the retainer element it can be used for a variety of different designs of corrugations and a variety of diameters and does not dislocate during assembly. The required retaining force is achieved by the retainer element having a diameter smaller than the diameter of the top of the elevation and hence is configured to engage with the depression. Thus, the retainer element works as a locking mechanism. Further, the retainer element is made of a material comprising a lower Young’s modulus as the sealing member and as the retainer elements are only partially extending along the circumference of the sealing member, the pipe seal can be widened to be positioned as required on the elevation.

In contrast, pipe seals comprising a sealing member positioned inside a groove have to be dimensioned to the diameter of the groove as otherwise not enough support is provided to press the seal against the socket pipe to seal the assembly. Further, this type of pipe seal does not require a retainer element as it is held in place by the side surfaces of the depression.

A partial extension along the circumference is to be understood in that the pipe seal comprises also expandable sections provided along the circumference of the sealing member not coupled to the retaining element.

A depression and an elevation as described above is in particular to be understood as a corrugation of a corrugated pipe. Different designs of pipes comprise in particular different shapes of corrugations. Different shapes include in particular semicircular and/or rectangular shapes. The rectangular shape comprises in particular a flat surface and/or a flat bottom surface. Further, the dimensions of the corrugations can also vary significantly in width or in depth of the elevation and/or the depression but also in the angle of the side surface of each depression and/or elevation.

According to a preferred embodiment, the first pipe and/or the second pipe can be configured as a corrugated pipe.

Preferably, the pipe seal comprises two retainer elements connected to the sealing member and extending partially along the circumference of the sealing member. The retainer elements are positioned opposite to each other on the circumference of the sealing member. Hence, the pipe seal can be secured in place more reliably by providing retaining forces applied to the sealing member on opposite sides across the circumference of the sealing member.

In a further advantageous embodiment, the pipe seal comprises three retainer elements. The retainer elements are connected to the sealing member and extend partially along the circumference of the sealing member. The retainer elements are essentially evenly distributed around the circumference of the sealing member. In a further preferred embodiment the pipe seal comprises a multiple of retainer elements, in particular twelve retainer elements. The more retainer elements are provided, which are evenly distributed around the circumference, the more evenly the retaining force is provided to the sealing member. Three retainer elements were found by experiments to be especially advantageous to provide a secure fit, and also to provide enough stability to form a circular shape in an unmounted state. The circular shape provides a further guidance for an easy assembly on a construction site. Twelve retainer elements were found to provide especially for large diameters, for example more than 1 meter, a secure fit by an even distribution of the retaining force around the circumference of the sealing member. Further, the pipe seal becomes more flexible as more interruptions between the retainer elements are provided. Hence, a transport becomes easier as it can be placed in smaller transport containers.

Preferably, the at least one retainer element extends between 10° and 70° along the circumference of the sealing member, preferably around 15° and/or 60°. With three retainer elements an extension of the retainer element of around 60° for each retainer element is preferred, whereby with twelve retainer elements an extension around 15° is preferred. The above described dimensions allow for enough stability of the pipe seal to be easily mounted on the pipe and to also provide enough retaining force to hold the sealing member in place.

Preferably, the at least one retainer element is made of polypropylene and preferably the sealing member is made of thermoplastic vulcanizate or ethylene- propylene-diene-rubber.

Preferably, the at least one retainer element comprises a contact section, configured to contact a side surface of the depression, and a sliding section, configured to slide along the inner side of the first pipe, wherein the sliding section is distant to the contact section. In particular, with pipes of small pipe diameter the retainer elements are pulled via the radially outer surface of the sealing member in such a way that the retainer elements tilt radially outwards. The sliding section will thereby contact the inner side of the first pipe when the distance between the contact sec- tion to the sliding section is longer than an opening between the first pipe and the second pipe. This configuration provides an increased support to hold the sealing member in place on the elevation.

Preferably, the retainer element is configured that a distance between the contact section and the sliding section is longer or smaller than an expanse of an opening in radial direction between the first pipe and the second pipe when coupling the first pipe with the second pipe.

Preferably, the cross section of the at least one retainer element has a triangular or rectangular shape. These shapes allow having only a corner being a sliding section and hence, reduce a surface friction between the sliding section and the inner side of the socket pipe.

Preferably, the sealing member comprises a sealing section having at least one sealing lip and an elongation section. The width in radial direction of the sealing section is greater than the width in radial direction of the elongation section. Preferably the elongation section is coupled with the retainer element. Thereby, the first pipe can be easily slid over the second pipe also having the pipe seal positioned on the elevation section. More preferably the sealing lip is directly supported by the elevation.

Preferably, the sealing member and/or the retainer element comprise a chamfer, configured to center the first pipe when coupling with the second pipe. This design helps an easy assembly of the pipes.

Preferably, the retainer element is at least partially coupled to a radial inner surface of the sealing member. Thereby, the elongation section can be further supported, and a more stable coupling is provided allowing a higher retaining force.

Preferably, the retainer element is coupled at least partially to the front surface of the sealing member. Thereby a thinner pipe seal is provided which allows the use with smaller pipe diameters and/or with a smaller opening between the first pipe and the second pipe. Preferably, the first pipe and/or the second pipe is configured as a corrugated pipe.

In a second aspect of the present invention the sealing system comprises a pipe seal as previously described, a first pipe, a second pipe comprising at least one depression and at least one elevation. The retainer element engages with the depression for holding the annular sealing member in place when coupling the first pipe with the second pipe.

Preferably, the first pipe is configured as a spigot pipe and the second pipe is configured as a corresponding socket pipe.

Preferably, the distance between the contact section and the sliding section of the retainer element is longer or shorter than an expanse of an opening in radial direction between the first pipe and the second pipe when coupling the first pipe with the second pipe.

Other features and advantages of the present invention will become apparent from the following more detailed description of the embodiments, which describe, by way of examples, the principles of the invention. Features of the embodiments may be combined with alternative embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a side view of a sealing system in an unmounted state comprising a pipe seal of a first embodiment and corrugated pipes;

Fig. 2 shows an enlarged cross-sectional view of section A of Fig.1 ;

Fig. 3 shows a cross-sectional view of section A of Fig. 1 in a first assembly step;

Fig. 4 shows a perspective view of the pipe seal of the first embodiment;

Fig. 5. shows a top view of the pipe seal of Fig. 4;

Fig. 6 shows a cross-sectional view of a pipe seal along the line B-B of Fig. Fig. 7 shows an enlarged view of section C of Fig. 6;

Fig. 8 shows a cross-sectional view of a second embodiment of the pipe seal;

Fig. 9 shows an enlarged view of section D of Fig. 8;

Fig. 10 shows a perspective view of a third embodiment of a pipe seal;

Fig. 11a shows a sealing system with the first embodiment of the pipe seal in a first assembly step;

Fig. 11 b shows a sealing system with the first embodiment of the pipe seal during a second assembly step;

Fig. 11c shows an assembled sealing system with the first embodiment of the pipe seal; and

Fig. 12 shows a sealing system with the second embodiment of the pipe seal during a second assembly step.

DETAILED DESCRIPTION OF THE DRAWINGS

The figures described below show examples of various embodiments. The same reference signs are used for identical or functionally identical components for all embodiments.

Fig. 1 shows a sealing system 100 according to a first embodiment. The sealing system 100 comprises a first pipe 110, a second pipe 120 and a pipe seal 10.

The first pipe 110 and the second pipe 120 are both corrugated pipes. The first pipe 110 is designed as a socket pipe and the second pipe 120 is designed as a spigot pipe.

The first pipe 110 comprises a front section 111 having a larger diameter compared to the outer diameter of the spigot pipe such that an opening 130 between the first pipe 110 and the second pipe 120 is formed. The opening 130 is shown in Fig. 3. The expanse of the opening 130 is measured with the first pipe 110 and the second pipe 120 having coincident center points. The front section 111 of the socket pipe comprises and inner side 112, which has an essentially flat surface.

The first pipe 110 and the second pipe 120 comprises a plurality of corrugations up to the end of the pipe. Each corrugation consists of a depression 122 and an elevation 124. Different designs of pipes differ in width or height of each depression 122 and/or elevation 124.

The depression 122 has a concave shape with a half circular form and the elevation 124 has a convex shape with half-circular form. In a different design, the shape of the depression 122 and/or elevation 124 could also be essentially rectangular having a flat top and/or bottom surface section.

As shown in Fig. 2, the pipe seal 10 according to a first embodiment comprises a sealing member 12 and at least one retainer element 21 . The sealing member 12 comprises a front face 15. At the front face 15 the retainer element 21 is connected to the sealing member 12. In this embodiment the sealing member 12 is vulcanized to the retainer element 21 in the section of the front face 15. The annular sealing member 12 has a sealing section 13 comprising a sealing lip 13a and an elongation section 14 starting from the sealing section 13 and extending to the retainer element 21 connected to the sealing member 12 partially around the circumference of the sealing member 12.

As shown in Fig. 3, the pipe seal 10 is positioned such that the elongation section 14 with the retainer element 21 faces the first pipe 110 and the sealing section 13 faces away of the first pipe 110 during a first assembly step. The sealing section 13 is positioned on top of the elevation 124 such that the sealing lip 13a forms the highest point being the furthest away of the center CE. The sealing section 13 is tightly applied to the elevation 124 as the diameter of the sealing member 12, in particular around the sealing section 13, is by design smaller than the diameter of the elevation 124.

Fig. 4 and Fig. 5 show the first embodiment of the pipe seal 10 with a sealing member 12 comprising three retainer elements 21 evenly distributed around the circumference of the annular sealing member 12. The retainer elements 21 are essentially identical. Each retainer element 21 extends with an angle a of about 60° along the circumference of the sealing member 12. Between the retainer elements 21 , the sealing member 12 comprises an expandable section 19 which also extends along about 60°along the circumference of the sealing member 12.

Fig. 6 and Fig. 7 show a detailed cross-sectional of the retainer element 21 which has an essentially rectangular shape. The retainer element 21 comprises a contact section 31 and a sliding section 32 distant to each other by distance d. In the front section, comprising the tip 34, a hook like shape is formed with a front side surface 33 extending from the tip to the sealing member 12.

The sealing member 12 comprises a front face 15 and a radial inner surface 16 coupled at least partially to the retainer element 21 . In particular the front face 15 is coupled to the curved section of the hook like shape of the retainer element 21 . The sealing member 12 comprises a sealing lip 13a. The sealing lip 13a is orientated at an angle to the radial direction. In particular the sealing lip 13a points towards the second pipe 120 in a lever like shape with the end face 17 forming a V with the section of the sealing member 12 comprising the radial inner surface 16.

The radial outer surface 18 forms with the front side surface 33 a chamfer.

Fig. 8 and Fig. 9 show a second embodiment of the pipe seal 10 comprising the retainer element 21 and the sealing member 12 in a cross-sectional view. The cross-section of the retainer element 21 has a triangular shape and comprises a contact section 31 and a sliding section 32 distant to the contact section 31 by a distance d. The sliding section 32 forms also the tip of the triangular shaped retainer element 21 . On the radial outer side the retainer element 21 comprises a front side surface 33.

The sealing member 12 further comprises the sealing lip 13a at the sealing section pointing radially outwards. On the radially inner side the sealing member 12 comprises a radial inner surface 16 and on the outer side the sealing member 12 comprises a radial outer surface 18. The sealing lip 13a forms a solid triangular shape with an end face 17 being parallel to a radial direction. The radial outer surface 18 and the front side surface 33 forms a chamfer. The chamfer has a smooth continuous surface.

Fig. 10 shows a third embodiment of the pipe seal 10 comprising twelve retainer elements 21 . All retainer elements 21 are evenly distributed around the circumference of the sealing member 12. Each retainer element 21 extends along an angle a of 15°.

Fig. 11a to Fig. 11c show the different assembly steps to assemble the sealing system 100. In all the above described embodiments of the pipe seal 10 the below assembly process is applied. For clarity reasons the assembly is described exemplary with a pipe seal 10 according to the first embodiment.

In a first assembly step as shown in Fig. 11a the pipe seal 10 is positioned on the second pipe 120. Hereto the pipe seal 10 is first widened in its diameter. The widening of the pipe seal 10 results mainly due to the expandable sections 19 being configured to deform elastically.

Next the pipe seal 10 is slid over the second pipe 120 until the sealing member 12 can be positioned on the elevation 124 with the sealing section 13 comprising the sealing lip 13a being directly supported by the elevation 124. The retainer element 21 are positioned on the side surface 123 of the depression 122 as the diameter of the retainer elements 21 is designed to be smaller than the diameter of the highest point of the elevation 124. Highest point refers to a point relative to a center of the pipe which is in an assembled state of the sealing system 100 coincident with the center CE of the pipe seal 10.

Fig. 11 b shows the second assembly step whereby the second pipe 120 having the pipe seal 10 in place is slid into the first pipe 110. The elongation section 14 is thereby stretched over the corrugation as the sealing member 12 is of an incompressible material. The retainer element 21 holds the sealing member 12 in place as the retainer elements 21 are engaged with the depression 122. The retaining elements 21 stay in place as they do not widen enough to also slide over the elevation 124. In particular for small pipe diameters the opening 130 is smaller than the distance d between the contact section 31 and the sliding section 32. Thereby, the contact section 31 stays in contact with the side surface 123 of the depression 122. During assembly the radially outer surface 18 pulls the retainer elements 21 more than the radially inner surface 16. Hence, the retainer element is tilted by being levered around the contact section 31 being in contact with the side surface 123 of the depression 122. The sliding section 32 is then rotated until being in contact with the inner side 112 of the first pipe 110. As the distance d is wider than the expanse of the opening 130, the sealing member 12 is held in place on top of the elevation 124. In contrast, Fig. 3 shows a configuration wherein the distance d is smaller than the expanse of the opening 130.

Finally, as shown in Fig. 11c, the first pipe 110 is assembled over the second pipe 120 with the pipe seal 10 sealing an opening 130 between the first pipe 110 and second pipe 120.

Fig. 12 shows a further example of a sealing system 100 during the second assembly step equivalent to Figure 11 b. The sealing system 100 differs in the pipe seal 10 being the second embodiment and in the pipe design comprising a different shape of corrugations. At this point it is outlined that the shown different pipe design has a rectangular shape with a flat top surface, a flat bottom surface and also a flat side surface 123 and only curved transmission sections between each flat section. This pipe design is an alternative embodiment of pipe design. It is outlined that the above described pipe seals 10 in the mentioned first, second and/or third embodiment can be used with this type of pipe design in the same manner according to the invention.

The pipe seal 10 enables the use with pipes of different designs of corrugations and/or a variety of diameters of pipes. Hence, the invention provides a cost effective and environmentally friendly solution in that only one design of a pipe seal is required which allows the use with different pipes. In particular, for pipes used for sewer and storm water applications this pipe seal allows for a sealing system 100 to ensure a waterproof fit for different designs and diameters of corrugated pipes. REFERENCE LIST

10 pipe seal

12 sealing member

13 sealing section

13a sealing lip

14 elongation section

15 front face

16 radial inner surface

17 end face

18 radial outer surface

19 expandable section

21 retainer element

31 contact section

32 sliding section

33 front side surface

34 tip a angle

CE Center

100 sealing system

110 first pipe

111 front section

112 inner side

120 second pipe

122 depression

124 elevation

130 opening