GB2264310A

GB2264310A - Sealed riser extension for access junction assembly

Info

Publication number: GB2264310A
Application number: GB9301282A
Authority: GB
Inventors: Michael Thomas Weldon
Original assignee: Wavin BV
Current assignee: Wavin BV
Priority date: 1992-02-24
Filing date: 1993-01-22
Publication date: 1993-08-25
Anticipated expiration: 2013-01-22
Also published as: GB9301282D0; GB2264310B

Abstract

A riser extension (50) comprises an extension side wall (51) having a first end (52) for engagement with the sidewall (6) of an access junction base section and a second end (53) for engagement with a riser side wall (25) of a riser section (3) of an access junction (1). The riser extension side wall (51) includes a radially inwardly stepped portion (55) having a groove (56) in which a ring seal (57) is mounted. A plurality of axially spaced-apart markings in the form of grooves (58) define locations for cutting the riser extension sides wall (51) to a desired length. An effective seal is maintained throughout the length of the riser assembly. <IMAGE>

Description

"Improvements in or relating to Access Junctions" The invention relates to improvements in or relating to access junction assemblies for drainage or sewage inspection chambers. More particularly the invention relates to improvements in or relating to the access junction assemblies described in Irish Patent Application No. 3181/88 corresponding to U.K. Application No.

2,224,047 A in the name of the present applicants.

U.K. 2,224,047 A describes an access junction assembly for a drainage and/or sewage inspection chamber comprising a base section, a riser section and a seal carried by the riser section. The base section includes a side wall having side inlets and a common outlet. The riser section comprises a top frame portion for receiving an access cover and a riser side wall extending from the frame portion for insertion into the socket defined by the base section side wall. The position of the riser may be readily- adjusted to take account of the inclination of the ground in which the access junction is mounted, and/or rotated to allow the frame portion of the rise; section to be positioned to follow the line of an adjacent building.

In addition, the vertical position of the riser relative to the base may be adjusted.

In some cases the vertical distance from the top frame portion to the base section of the access junction may be longer than the riser side wall. Heretofore an extension piece comprising a length of pipe of required diameter has been used to form a riser extension. However, such extension pieces are difficult to fit and to not in some cases maintain an adequate seal.

This invention is directed towards providing an improved riser extension for such an access junction assembly.

According to the invention there is provided a riser extension for an access junction of the type comprising a base section having a floor portion and a base section side wall extending from the floor portion, and a riser section having a top frame portion for receiving an access cover and a riser side wall extending from the frame portion, the riser extension comprising an extension side wall having a first end for engagement with a side wall of an access junction base section or another riser extension, and a second end for engagement with the riser side wall or another riser extension, the first end of the riser extension being a tight fit in an access junction base section side wall or another riser extension.

In a particularly preferred embodiment of the invention on assembly, the outer dimension of the riser extension side wall is approximately the same as the outer dimension of the side wall of the access junction so that the assembly provides a side wall of substantially the same outer dimension along its length.

In one embodiment of the invention the first end of the riser extension includes a step portion for sealing engagement with an access junction base section side wall.

In a preferred embodiment of the invention, the step portion is stepped radially inwardly and sealing means are provided between the step portion and the base section side wall.

In another embodiment of the invention the step portion includes a circumferentially extending groove and the sealing means comprises a seal, preferably an O-ring seal mounted in the groove for sealing engagement with the base section side wall.

In a preferred embodiment of the invention the extension side wall includes a plurality of axially spaced-apart markings defining locations for cutting the riser extension side wall to a desired length.

In one embodiment of the invention the marking comprises grooves formed in the extension side wall.

The invention also provides an access junction assembly including one or more riser extensions according to the invention The invention will be more clearly understood from the following description thereof given by way of example only with reference to the accompanying drawings in which: Figs. 1 to 4 are respectively perspective, plan, diagrammatic cross-sectional, and detailed cross sectional side views of an access junction of the prior art, Fig. 5 is an exploded view of a riser extension according to the invention, Fig. 6 is an exploded perspective view of the riser extension and access junction assembly, Fig. 7 is a diagrammatic cross-section side view of the access junction assembly and riser extension in use, and Fig. 8 is a side view of another access junction assembly according to the invention.

Referring to the drawings and initially to Figs. 1 to 4 thereof there is illustrated an access junction of the prior art which is indicated generally by the reference numeral 1. The access junction 1 of the prior art comprises a base section 2 and a riser section 3 which is adjustable mounted to the base section 2. A seal 4 is provided between the base section 2 and the riser section 3.

The base section 2 comprises a floor portion 5 and a base section sidewall 6 extending upwardly from the floor portion 5. The base section sidewall 6 in this case has a straight-through inlet 7 and outlet 8 which have a common central longitudinal axis. Two side inlets 9, 10 are also provided for connection to pipes which extend, in this case, at angles of 45" and 90" respectively to the straight-through pipe run. It will be noted that the floor portion 5 is configured and shaped adjacent the inlets 7, 9, 10 to direct fluid flow to the outlet 8.

Each of the inlets 7, 9 and 10 and outlet 8 are provided with socket connections 12 having seals 13 which extend to engage the sidewall of a pipe inserted into the socket 12.

In the case of the side inlets 9, 10 it will be noted that the diameter of each inlet downstream of the seal 13 is enlarged at 15 to accommodate small variations in the angle at which a pipe is entered to the sockets 12. The inlet 7 and outlet 8 may also have enlarged portions.

This allows the access junction 1 to take up variations in the angle of the inlet pipes.

The riser section 3 comprises a top frame portion 26 for receiving an access cover, not shown and a riser sidewall portion 25 extending from the frame portion for insertion into the socket defined by the base section sidewall 6 with the seal 4 interposed therebetween.

In this case, the seal 4 comprises a ring seal confined in a groove defined between a pair of spaced-apart sidewardly projecting ledges 31, 32 (see Fig. 4) extending from the outside surface of the riser sidewall portion 25. The seal 4 is D-shaped in transverse cross-section and the flat surface of the seal 4 engages the riser side wall and the curved surface of the seal 4 engages against the inner surface of the base section side wall 6. In this way, twisting of the seal is prevented.

The seal 4 allows the riser section 3 to be manipulated within the base section 2 to achieve a desired position of the top frame portion 26. Thus, the position of the riser section 3 may be adjusted to take account of the inclination of the ground in which the access junction 1 is mounted and/or rotated to allow the frame portion 26 of the riser section 3 to be positioned to follow the line of an adjacent building. Further, the vertical position of the riser 3 relative to the base 2 can be easily adjusted.

Referring to Fig. 5 and 6 the access junction assembly according to the invention includes a riser extension 50 also according to the invention. The riser extension 50 is of tubular construction and comprises an extension side wall 51 having a first end 52 for engagement with the side wall 6 of the access junction base section and a second end 53 for engagement with the riser side wall 25 of the riser section 3. The first end 52 of the riser extension 50 is arranged to be a tight fit in the access junction base section side wall 6.

In more detail, and referring particularly to Fig. 5, it will be noted that the first end 52 of the riser extension side wall 51 includes a radially inwardly stepped portion 55 having a circumferentially extending groove 56 in which an O-ring seal 57 is mounted.

It will be noted particularly from Fig. 7 that the riser extension 50 is thus a tight fit in the base section side wall 6. The outer diameter of the riser extension side wall 51 above the stepped portion 55 is the same as the outer diameter of the base section side wall 6 so that, in effect, the riser extension forms an extension of the riser section side wall 6 and the riser extension 50 does not move as the riser section 3 is inserted into the upper or second end 53 of the riser extension 50. In this way, an effective seal is maintained throughout the length of the base side wall and riser extension side wall 51. In addition, because of the added height of the extension side wall an even greater telescopic effect is available than would be available with an assembly comprising just a base section 3 and riser section 3 alone.This is because the benching in the floor of the base section 2 does not interfere with the depth to which the riser section 3 may be inserted into the assembly.

The riser extension side wall 51 also includes a plurality of axially spaced-apart markings, in this case comprising circumferentially extending grooves 58 defining locations for cutting the riser extension side wall to a desired length.

It will be appreciated that more than one riser extension 50 according to the invention may be used in an access junction assembly. For example, referring to Fig. 8, an access junction assembly is illustrated which includes two riser extensions according to the invention. The upper of the riser extensions 50 is inserted into the lower extension in a similar manner to the manner in which the lower riser extension is inserted into the base section side wall 6 as illustrated in Fig. 7. In this way a tight fit for the riser extension is assured and the riser section 3 of the assembly may then be easily manoeuvred into a desired position.

Many variations on the specific embodiment of the invention will be readily apparent and accordingly the invention is not limited to the embodiments hereinbefore described but may be varied in both construction and detail.

Claims

1. A riser extension for an access junction of the type comprising a base section having a floor portion and a base section side wall extending from the floor portion, and a riser section comprising a top frame portion for receiving an access cover and a riser side wall extending from the frame portion, the riser extension comprising an extension side wall having a first end for engagement with a side wall of an access junction base section or another riser extension, and a second end for engagement with the riser side wall or another riser extension, the first end of the riser extension being a tight fit in an access junction base section side wall or another riser extension.

2. A riser extension as claimed in claim 1 wherein on assembly, the outer dimension of the riser extension side wall is approximately the same as the outer dimension of the side wall of the access junction so that the assembly provides a side wall of substantially the same outer dimension along its length.

3. A riser extension as claimed in claim 1 or 2 wherein the first end of the riser extension includes a step portion for sealing engagement with an access junction base section side wall.

4. A riser extension as claimed in claim 3 wherein the step portion is stepped radially inwardly and sealing means are provided between the step portion and the base section side wall.

5. A riser extension as claimed in claim 3 or 4 wherein the step portion includes a circumferentially extending groove and the sealing means is mounted in the groove for sealing engagement with the base section side wall.

6. A riser extension as claimed in claim 4 wherein the sealing means comprises an O-ring seal.

7. A riser extension as claimed in any preceding claim wherein the extension side wall include a plurality of axially spaced-apart markings defining locations for cutting the riser extension side wall to a desired length.

8. A riser extension as claimed in claim 7 wherein the marking comprise grooves formed in the extension side wall.

9. A riser extension substantially as hereinbefore described with reference to the accompanying drawings.

10. An access junction assembly including one or more riser extensions as claimed in any preceding claim.