GB2329438A

GB2329438A - Saddle-type pipe branch connection

Info

Publication number: GB2329438A
Application number: GB9820041A
Authority: GB
Inventors: Jean-Claude Hauer; Serge Renard
Original assignee: Pont a Mousson SA
Current assignee: Pont a Mousson SA
Priority date: 1997-09-17
Filing date: 1998-09-16
Publication date: 1999-03-24
Anticipated expiration: 2018-09-16
Also published as: DE19842259A1; GB2329438B; DE19842259B4; FR2768488A1; GB9820041D0; FR2768488B1

Abstract

The connection (10) comprises a saddle-type connector (11) which has a cylindrical part (15) projecting below a radially extending saddle (13) and for insertion into a circular cutout previously made in the wall of a main sewer (12), and an annular packing interposed between the connector (11) and the main sewer (12). The packing has an axial-compression sealing body (2) for abutting the sewer wall around the cut-out and an extension (3) extending into the interior of the cutout intended to ensure the protection against corrosion of the edge (16) of the cutout.

Description

2329438 1 Connection device for the leaktight Junction of a pipe to a main

sewer The invention relates to sewerage piping. It concerns more particularly the connection devices used to connect a pipe to a main sewer, for example for connecting a house drainage pipe to a larger-diameter main sewer of the sewerage system.

In order to do this, a support connector, known from the prior art, such as for example that which is described in the German Utility Model DEGm 90 15 652.8, is used. This type of connector includes a male cylindrical end part intended to be introduced into a circular opening previously cut out of the main sewer, the said cylindrical part extending radially outwards by way of a collar called a saddle. Opposite the cylindrical part, the connector has a configuration adapted to effect the junction of the connector with the drainage pipe, thus permitting the latter to be connected to the main sewer.

The saddle is provided with a circular groove concentric with the male cylindrical part of the connector and intended to receive a roll for centring a packing when the latter straddles the circular cutout of the main sewer. The saddle further has means for fixing it to the main sewer, such as for example bores for receiving fixing bolts.

The packing made of elastomer forms a radial -compression joint and ensures the sealing between the branch connector and the main sewer. The packing consists of the centring roll as well as a cylindrical sealing ring which, when the packing is installed in the position of readiness on the pipe, presses radially onto the edge of the cutout. The said roll, which is half-round, caps the ring externally while pressing onto the outer surface of the main sewer on the border of the cutout, thus preventing the cylindrical ring from sliding towards the interior of the said sewer.

During the fitting of the connector onto the main sewer and the introduction of its male cylindrical part into the interior of the packing, the cylindrical ring of the packing is

2 radially compressed between the cylindrical part of the connector and the edge of the circular cutout, the half-round roll holding the packing in place and being lodged, when the introduction is complete, in the circular groove of the saddle.

The said radial-compression packing has a number of disadvantages, especially disadvantages connected with the dimensional accuracy of cutting out the circular opening from the main metal sewer, this being performed on site by means of a milling cutter and the vibrations at the tool being such that the diametrical tolerances are often exceeded. Consequently, if the diameter of the opening is too large, the packing is not sufficiently compressed to ensure correct sealing. In contrast, if the diameter of the opening is too small, the packing is subjected to too many stresses during the introduction of the connector, especially at the place where the packing is in contact with the arris formed by the external surface of the sewer and the edge of the cutout, where these stresses can lead to a tearing of the packing which from then on no longer ensures its sealing function.

Moreover, the radial-compression packing also has an anticorrosion function vis-A-vis the edge of the cutout onto which it is applied and where the metal is stripped. If it does not cover the said edge completely with a minimum application force, this function is not ensured, since the fluid could come into contact with the metal and attack it.

Finally, the fixing of the connector onto the main sewer is ensured by at least two bolts which are equipped with sealing sleeves passing through the wall of the sewer in line with each bore of the saddle and are tightened by nuts. The lack of accuracy of the bore made in the main sewer causes the connector to be thrown off centre with respect to the cutout, which once again leads to a sealing defect.

The object of the present invention is to remedy all these disadvantages. To that end, the subject of the invention is a connection device for the leaktight junction of a pipe to a main sewer, comprising a saddle-type connector which has, on an 3 axis X-X, a cylindrical part projecting under the saddle and intended to be introduced into a circular cutout previously made in the wall of the main sewer, as well as an annular packing interposed between the connector and the main sewer, the packing having an axial-compression sealing body extending towards the interior of the cutout by way of a substantially cylindrical skirt intended to ensure the protection against corrosion of the edge of the cutout.

According to other characteristics of the invention:

- the sealing body, when the packing is in place, comes to bear on the outer periphery of the cutout, while the skirt covers the edge of the said cutout; - the sealing body, when the packing and the connector are in place, has an oblong section whose major axis is parallel to the axis X-X of the connector; - the packing includes an annular expansion chamber for the material of the sealing body when the latter is axially compressed, the said chamber being formed at the base of the sealing body and at the intersection of the latter with the skirt so as to cover the external circular arris of the cutout; - the skirt of the packing includes on its internal wall at least one means for applying the skirt onto the edge of the cutout when the connector is in place; - the means for applying the skirt consists of at least one circular lip; the skirt of the packing includes on its internal wall a means for centring the connector on the packing; - the centring means comprises at least three ribs oriented axially and evenly spaced over the internal periphery of the skirt; - the internal wall of the compression body of the packing has a slight conicity in order to facilitate the introduction of the saddle-type connector when the packing is in place on the cutout.

The invention will be better understood on reading the description which follows, given purely by way of example and

4 with reference to the accompanying drawings, in which:

- Fig. 1 is an elevational and sectional view of a packing of a connection device according to the invention; - Fig. 2 is a partial sectional view of a connection device using a packing according to Fig. 1, installed on a main sewer.

The packing 1 shown in Figure 1 is made of an elastomer material and is intended to be installed between a saddle-type support connector and an opening made in a main sewer.

This annular packing 1 consists of an annular, oblongsection sealing body 2 extended internally by a roughly cylindrical skirt 3. The outer surface of the skirt 3 is free from protrusions, while its inner surface is provided, from the bottom up, with two parallel circular lips 4, 5 which extend upwards by way of ribs 6 for centring the connector. These ribs 6, of which there are at least three, are perpendicular to the said lips and evenly spaced over the internal periphery of the skirt 3.

At the intersection of the external upper part of the skirt 3 and of the lower part of the sealing body 2, an annular groove 7 forms an expansion chamber for the elastomer material of the sealing body 2 when the latter is compressed.

Figure 2 shows the connection device 10 according to the invention installed on a round cutout made in a main sewer 12 of axis Y-Y in order to connect it to a secondary pipe (not shown).

This device 10 consists of a saddle-type connector 11 of axis X-X which receives the packing 1.

The connector 11 comprises a saddle 13 which extends radially outwards and which extends axially inwards by way of a lower cylindrical part 15 intended to be introduced into the cutout. The upper part of the connector 11 is provided with means (not shown) for joining it to the secondary pipe.

The connector 11 is further provided with an annular housing 14 for receiving the sealing body 2 of the packing 1.

The saddle 13 is provided with two diametrically opposite bores 18 intended for the fixing of the connector 11 onto the main sewer 12 by means of bolts 17.

The round cutout made in the metal wall of the sewer 12 has a circular cutout edge 16 where the metal is stripped.

The packing 1, consisting of the oblong compression body 2 and the skirt 3, surrounds the round cutout in a manner such that the external wall of the skirt 3 is laid against the cutout edge 16 and that the sealing body 2 rests by way of its lower part on the outer surface of the sewer 12 delimiting the cutout, the longitudinal direction of the oblong section of the body 2 being parallel to the axis X-X of the connector. The annular groove 7 covers, in these conditions, the arris 22 formed by the edge 16 of the cutout with the outer surface of the wall of the main sewer 12.

The connector 11 of axis X-X fits axially into the packing 1. This operation is facilitated by a slight conicity of the inner profile of the compression body 2 of the packing, by a smoothing of the angles of the centring ribs 6 and by the orientation of the lips 4, 5.

On axial introduction into the packing 1 installed on the periphery of the round cutout, the connector 11 receives in its annular housing 14 the body 2 of the said packing 1, while its cylindrical end 15, sliding axially on the centring ribs 6 successively on the circular lip 5 then the circular lip lays the external face of the skirt 3 against the edge 16 and 4, of the cutout, thus ensuring the protection against corrosion of the edge 16.

In order to effect the fixing of the connector 11 onto the main sewer 12, bores 19 are made in the wall of the sewer 12 in line with the bores 18 of the saddle 13. The bolts 17, provided with sealing sleeves 20, are then introduced into the bores 19 from inside the main sewer 12 and are made to pass through the bores 18 to cooperate with clamping nuts 21.

The simultaneous tightening of the nuts 21 brings the saddle 13 in parallel closer to the main sewer 12. More particularly, the tightening of the nuts 21 compresses the 6 sealing body 2 of the packing 1 axially between the bottom of the housing 14 of the connector 11 and the external wall of the main sewer 12 in order to ensure the sealing of the connection device.

During the compression of the body 2, the circular groove 7 permits a reduction of the stresses in the packing 1 at the arris 22 formed by the cutout edge 16 and the external wall of the main sewer, thus preventing damage to the packing.

The present invention thus permits a dissociation of the anticorrosion function of the cutout edge 16, ensured by the skirt 3, from the sealing function performed by the compression body 2.

7

Claims

1. Connection device (10) for the leaktight junction of a pipe to a main sewer (12) comprising a saddle-type connector (11) which has, on an axis X-X, a cylindrical part (15) projecting under the saddle (13) and intended to be introduced into a circular cutout previously made in the wall of the main sewer (12), as well as an annular packing (1) interposed between the connector (11) and the main sewer (12), characterized in that the packing (1) has an axial-compression sealing body (2) extending towards the interior of the cutout by way of a substantially cylindrical skirt (3) intended to ensure the protection against corrosion of the edge (16) of the cutout.

2. Connection device according to Claim 1, characterized in that the sealing body (2), when the packing is in place, comes to bear on the outer periphery of the cutout, while the skirt (3) covers the edge (16) of the said cutout.

3. Connection device according to Claim 1 or 2, characterized in that the sealing body (2), when the packing (1) and the connector (11) are in place, has an oblong section whose major axis is parallel to the axis X-X of the connector.

4. Connection device according to any one of Claims 1 to 3, characterized in that the packing (1) includes an annular expansion chamber (7) for the material of the sealing body when the latter is axially compressed, the said chamber being formed at the base of the sealing body and at the intersection of the latter with the skirt (3) so as to cover the external circular arris (22) of the cutout.

5. Connection device according to any one of Claims 1 to 4, characterized in that the skirt (3) of the packing (1) includes on its internal wall a means (4, 5) for applying the skirt (3) onto the edge (16) of the cutout when the connector (11) is in place.

6. Connection device according to Claim 5, characterized in that the means (4, 5) for applying the skirt (3) consists of at least one circular lip (4, 5).

8

7. Connection device according to any one of Claims 1 to 6, characterized in that the skirt of the packing (1) includes on its internal wall a means (6) for centring the connector (11) on the packing (1).

8. Connection device according to Claim 7, characterized in that the centring means (6) comprises at least three ribs (6) oriented axially and evenly spaced over the internal periphery of the skirt (3).

9. Connection device according to any one of Claims 1 to 8, characterized in that the internal wall of the compression body of the packing (1) has a slight conicity in order to facilitate the introduction of the saddletype connector (11) when the packing is in place on the cutout.