Technical field

[0001] The present invention relates generally to pipe connections and more particularly to a pipe connection assembly with an improved sealing arrangement facilitating the connection procedure.

Background art

[0002] In prior art connections assemblies, it is known to arrange a sealing ring having a circular cross-section between an outer pipe and an inner pipe connected to each other. This sealing ring, or O-ring, is conventionally positioned in a circumferential groove in the inner or outer pipe before the connection procedure and the inner pipe is then inserted into the outer pipe for forming a connection.

[0003] One drawback with these prior art connections is that the sealing ring may be displaced before or during the insertion of the inner ring, causing a faulty seal.

Summary of invention

[0004] An object of the present invention is to provide a pipe connection assembly of the kind initially mentioned, wherein the risk of faulty seal is reduced.

[0005] The invention is based on the insight that the sealing ring may be provided with a cross-sectional shape different from circular.

[0006] According to a first aspect of the invention, there is provided a pipe assembly for a drainage system, comprising: a pipe with a wall having an inner surface, the pipe ending in an outermost end portion; a circumferential groove in the inner surface of the wall at the outermost end portion; a sealing ring being arranged in the circumferential groove in a plane extending perpendicular to the longitudinal direction of the pipe; the sealing ring having a cross-sectional shape comprising an essentially planar, slanting surface facing away from circumferential groove, the slanting surface being at a first angle to the plane of the sealing ring; the pipe assembly being characterized in that the cross-sectional shape of the sealing ring has an abutment surface adjacent to the slanting surface and facing away from circumferential groove, the abutment surface having a surface being at a second angle to the plane that is smaller than the first angle.

[0007] In a preferred embodiment, the cylindrical wall comprises a spacing means in the form of a plurality of longitudinal ribs provided on the inner surface of the cylindrical wall. The longitudinal ribs are preferably concentrically provided and all have the same thickness.

[0008] In a preferred embodiment, an outermost portion of the cylindrical wall is formed as a curved flange of which the inner surface forms the circumferential groove.

[0009] In a preferred embodiment, the sealing ring has a cross-sectional shape further comprising a surface facing the groove and has a curvature that is adapted to a curvature of the curved flange of which the inner surface forms the circumferential groove.

[0010] In a preferred embodiment the sealing ring has a cross-sectional shape further comprising a surface facing the groove and has a curvature that is adapted to a curvature of the curved flange of which the inner surface forms the circumferential groove.

[0011] In a preferred embodiment, in the cross-sectional shape, the slanting surface ends in a tip.

[0012] In a preferred embodiment, the cross-sectional shape comprises a third surface, preferably planar surface, which faces away from the outermost end portion of the pipe and is essentially parallel to the plane.

[0013] In a preferred embodiment, the second angle is at least 10 degrees, preferably at least 20 degrees, even more preferably at least 30 degrees smaller than the first angle at some point of the abutment surface. [0014] The pipe assembly according to any one of the preceding claims, wherein the first angle is between 95 degrees and 120 degrees, preferably between 100 and 110 degrees, and most preferably about 105 degrees.

[0015] According to a second aspect of the invention, a water trap is provided comprising an inlet portion and an outlet portion, wherein at least the outlet portion comprises a pipe assembly according to the invention.

[0016] According to a third aspect of the invention, a sealing ring is provided having a cross-sectional shape comprising a third surface, preferably planar surface, extending essentially parallel to a plane; a first surface connected to a second surface and which is an essentially planar, slanting surface being at a first angle to the plane of the sealing ring; the second surface opposing the first surface and having a curvature such that it is connected to the first surface; and an abutment surface opposing the first surface and adjacent to the first surface and the third surface, the abutment surface having a surface being at a second angle to the plane that is smaller than the first angle.

[0017] In a preferred embodiment of the sealing ring, the second angle is at least 10 degrees, preferably at least 20 degrees, even more preferably at least 30 degrees smaller than the first angle at some point of the abutment surface (14e).

[0018] In a preferred embodiment of the sealing ring, the first angle is between 95 degrees and 120 degrees, preferably between 100 and 110 degrees, and most preferably about 105 degrees.

Brief description of drawings

[0019] The invention is now described, by way of example, with reference to the accompanying drawings, in which:

Fig. 1 is an overall view of a water trap comprising a pipe assembly according to the invention;

Fig. 2a is a perspective view of an end section of a pipe comprised in a pipe assembly according to the invention; Fig. 2b is a sectional view through the pipe shown in Fig. 2a;

Fig. 3a is a plan view of a sealing ring comprised in the pipe assembly according to the invention;

Fig. 3b is a cross-sectional view of the sealing ring shown in Fig. 3a taken along the line A-A;

Figs. 3c and 3d show enlarged views of the cross-sectional shape of the sealing ring in two different embodiments;

Figs. 4a-c show different stages of insertion of an inner pipe into the pipe shown in Figs. 2a and 2b;

Fig 5 is a sectional view of the pipe shown in Figs. 2a and 2b with an inner pipe inserted therein;

Fig. 6a is a side view of the pipe shown in Figs. 2a and 2b with an outer pipe on the outside thereof; and

Fig. 6b is a section view of the pipe shown in Fig. 6a taken along the line A-A. Description of embodiments

[0020] In the following, a detailed description of a pipe assembly according the invention, comprising a pipe and a sealing, will be given

[0021] Turning first to Fig. 1 , a water trap in the form of a so-called bottle trap is shown, generally designated 1. The water trap 1 comprises a vertical inlet portion 2 in the form of a pipe and a horizontal outlet portion 10 in the form of a pipe. The inlet portion 2 and outlet portion 10 have circular cross-sectional shape. The horizontal outlet portion 10 comprises a tubular pipe with a pipe wall having an outer surface and an inner surface.

[0022] A cup 6 is detachably attached to the lower end of the water trap 1. The outlet portion 10 is adapted to be connected to a connection pipe 20, see Fig. 5, with an outer diameter adapted to allow a press fit between the outlet portion 10 and the connection pipe 20, wherein the outlet portion 10 forms an outer pipe and the connection pipe forms an inner pipe in a pipe assembly.

[0023] Turning now to Figs. 2a and 2b, an end section of the outlet portion 10 is shown. A spacing means in the form of a plurality of longitudinal ribs 12 is provided on the inner surface of the wall 10a of the outlet portion 10. From the sectional view shown in Fig. 2b it is evident that the pipe wall 10a has a uniform thickness and that the spacing means is concentrically provided on the inner surface. This means that all ribs have the same thickness, i.e. , they extend the same distance towards the center axis of the outlet portion 10.

[0024] A sealing ring 14 is provided in a circumferential groove 10c in the inner surface of the wall 10a constituting the outlet portion 10. The sealing ring has a cross-sectional shape shown in Figs. 3b and 3c which is adapted for easy insertion of the connection pipe 20 according to Fig. 5. To this end, the cross- sectional shape exhibits a slanting surface 14b which ends in a tip 14a when looking out of the outlet portion 10. The sealing ring 14 has a plane P and the slanting surface 14b is at a first angle a to the plane P of the sealing ring 14, see Fig. 3c. When determining this angle to the plane P, it is the angle between the plane P in the inner of the sealing ring 14 and the plane of the slanting surface 14b. In the shown embodiment, the first angle a is about 105 degrees, but it may vary between 95 degrees and 120 degrees, preferably between 100 and 110 degrees.

[0025] The surface 14c of the cross-sectional shape of the sealing ring 14 facing the groove 10c has a shape or curvature that is adapted to the curvature of the circumferential groove 10c. The surface 14d of the cross-sectional shape of the sealing ring 14 facing the ribs 12 is preferably planar.

[0026] Finally, an abutment surface 14e is formed between the surface 14d facing the ribs and the slanting surface 14b. The abutment surface 14e is designed to contact the outer surface of an inserted connection pipe 20, see Fig.

5. To this end, the abutment surface 14e has a surface being at a second angle b to the plane P that is smaller than the first angle a. Although in fig. 3c there is a smooth transition from the slanting surface 14b to the abutment surface 14e, the second angle b must be substantially smaller than the first angle a at some point along the abutment surface 14e. In other words, the second angle b should preferably be at least 10 degrees, preferably at least 20 degrees, even more preferably at least 30 degrees smaller than the first angle a at some point of the abutment surface 14e.

[0027] By giving the abutment surface this angle, less material in the ring would have to be compressed during insertion of a connection pipe as compared to the case when an essentially planar slanting surface extends all way to the surface facing the ribs 12.

[0028] In the embodiment shown in Fig. 3c, the abutment surface is curved, i.e. , has a radius. This means that the angle b varies along this abutment surface 14e, from an angle essentially corresponding to the angle a to a smaller angle, in Fig.

3c approximately 80 degrees. This means that the material in the sealing ring 14 easily can be redistributed, making compression easier.

[0029] The abutment surface can take other shapes as long as the angle b is smaller than the angle a. Thus, in Fig. 3d, the angle of the slanting surface is the same as in the embodiment of Fig. 3c, while the abutment surface is at essentially right angle to the plane P of the sealing ring 14.

[0030] Turning again to Fig. 2b, the outermost portion of the outlet portion 10 is formed as a curved flange 10b of which the inner surface forms the groove 10c. Thus, this groove 10c in which the sealing ring 14 is placed, together with the ribs 12, delimit the movement of the sealing ring 14, i.e., holds the sealing ring in place.

[0031] In Figs. 4a-c, it is shown how the circular end surface 20a, see Fig. 4a, of the connection pipe 20 facing the outlet portion 10 during insertion will slide on the slanting surface 14b, see Fig. 4b, when the outlet portion 10 and the connection pipe 20 begin to engage. Thanks to the slanting surface 14b of the sealing ring 14 which ends in a tip 14a, which is surrounded by the outer tip of the curved flange 10b, the insertion of the connection pipe 20 is facilitated. During further insertion, see Fig. 4c, the outer surface of the connection pipe 20 will continue to slide on the abutment surface 14e while slightly compressing the sealing ring 14 to ensure a tight fitting between the outlet portion 10 and the connection pipe 20. Thanks to the shape of the slanting surface 14b, unintentional displacement of the sealing ring 14 is avoided. Thanks to the design with an abutment surface 14e having a surface being at a second angle b to the plane P that is smaller than the first angle a of the slanting surface 14b., this connection pipe 20 will compress the sealing ring 14 to a limited degree. This is particularly useful when the sealing ring is manufactured from a material with a lower degree of flexibility than for example rubber, such as silicone. The stiffer nature of silicone also ensures that the sealing ring 14, once placed in the groove 10c, will be difficult to remove.

[0032] In Fig. 5, the connection pipe 20 with an outer diameter corresponding to the distance between diametrically opposite longitudinal ribs 12 is shown. This means that the connection pipe 20 during assembly is brought to slide into the inner of the outlet portion 10.

[0033] In Figs. 6a and 6b an alternative connection pipe 20’ of a different standard is shown where the connection pipe 20’ has an inner diameter corresponding to the outer diameter of the outlet portion 10 and may thus be brought on the outside of the outlet portion 10. This is facilitated by the distal end of the outlet portion 10 having a curved outer surface or flange. The alternative connection pipe 20’ is provided with a sealing ring 24, preferably with a lip which in connected state is deflected and rests against the outer surface of the wall 10a of the outlet portion 10. In this way, the flexibility of connecting to connection pipes of different standards is obtained.

[0034] Fig. 5 and Figs. 6a and 6b show the possibility of connecting the outlet portion 10 to connection pipes of different standards and thus different diameters. Thanks to the longitudinal ribs 12 which decrease the inner diameter of the outlet portion 10, the wall 10a of the outlet portion 10 can be made with uniform but still small thickness, which from a manufacturing point of view is an advantage, since it is difficult to manufacture a tube with a large or non-uniform thickness. Also, the amount of material is kept down with this solution.

[0035] Embodiment of a pipe connection assembly according to the invention have been described. It will be appreciated that the principles thereof are applicable also to other applications than water traps. Thus, for example Fig. 2a shows a general design of a pipe assembly which may be used in any part of a piping system.

[0036] Also, although it is preferred to use the inventive concept of the sealing ring together with a pipe with internal longitudinal ribs, it will be appreciated that the claimed pipe assembly is not limited to this design but can also be used with pipes with smooth inner surface, as long as there is a circumferential groove therein.

[0037] In the preferred embodiment, the distal end of the outlet portion 10 is formed as a curved flange 10b of which the inner surface forms the groove 10c. The outer surface of the outlet portion may take other shapes as long as the tip 14a of the sealing ring 14 rests in the groove.