EP1183429A1

EP1183429A1 - Access cover

Info

Publication number: EP1183429A1
Application number: EP00935305A
Authority: EP
Inventors: Nigel Capon
Original assignee: Geberit Ltd
Current assignee: Polypipe Terrain Ltd
Priority date: 1999-05-21
Filing date: 2000-05-22
Publication date: 2002-03-06
Anticipated expiration: 2020-05-22
Also published as: DE60017555D1; WO2000071835A1; GB2350169B; AU5085900A; EP1183429B1; ATE287479T1; GB0012363D0; GB2350169A; ES2248079T3; GB9911716D0; NL1015257C2

Abstract

An access cover for connecting to a rainwater pipe (10, 11) or the like comprises an outer tubular section (1) and an inner tubular section (2) nested at least partially within the outer tubular section. An access aperture (3) is provided in the inner tubular section such that in use, the rainwater pipe can be inspected and a rod can be inserted into the rainwater pipe for cleaning. The access aperture is covered by the outer tubular section and relative movement is permitted between the inner and outer tubular sections such that in use, the access aperture may be covered and uncovered easily. In one embodiment the outer tubular section contains a second access aperture corresponding to the first access aperture; in this case rotary motion between the inner and outer tubular sections is possible. In another embodiment the outer tubular section is arranged to slide over the access aperture in a direction substantially parallel to the axis of the tubular sections.

Description

ACCESS COVER

Field of the Invention

This invention relates an access cover for use with rainwater pipes, domestic waste pipes, soil pipes and the like.

Description of the prior art

Rainwater pipes and other types of pipes such as waste pipes and down pipes often require maintenance, for example, if the pipe becomes blocked or damaged. For this reason access to waste pipes is often provided for maintenance and inspection by using so called access pipes which are connected into the waste pipe that may require maintenance. Known access pipes are sections of pipe which contain an aperture through which the waste pipe can be inspected and through which rods can be inserted to the waste pipe to remove blockages. The access pipe is typically connected at a bend or junction in a waste pipe so that rods can be inserted into the waste pipe in each direction away from the bend or junction.

Apertures in known access pipes are typically closed during normal use by covering them with panels or access covers which are fixed into place using bolts or screws. This leads to a problem in that in order to open the aperture the bolts or screws have to be unfastened and the access cover removed. This is time consuming and difficult because the waste pipe itself is usually located in a place that is not easy to access. For example, on the outside wall of a house. Also, once the access cover is removed it is independent of the waste pipe and there is a danger that it may be mislaid or the bolts or screws lost. After maintenance work has been completed the access cover must be replaced and this is also a time consuming and difficult operation.

Another problem is that the bolts or screws can become corroded over time and this makes the access cover particularly difficult to remove. Further the cover itself is bulky and unseemly and together with the bolts or screws does not create a pleasing appearance. This is a particular problem in the case that the waste or rainwater pipe is located on the outside of a building in a prominent position.

Alternatively, the cover made be threaded to screw into a threaded aperture in the access pipe. This arrangement dispenses with the need for screw or bolt fixings but gives rise to different problems. To avoid impinging on the flow of the fluid in the pipe, the threaded region of the access pipe inevitably protrudes proud of the general line of the pipe. Thus, this type of access pipe is generally bulky and this can cause problems when they have to be installed in confined spaces.

The cover can require a special tool to remove it and if this is not available plumbers tend to use a screwdriver or other leaver instead. This can permanently deform the fitting and make access difficult on subsequent occasions.

It is accordingly an object of the present invention to provide an access cover which overcomes or at least mitigates one or more of the problems noted above.

Summary of the Invention

According to a first aspect of the present invention there is provided an access cover for providing access to a pipe in use comprising: an outer tubular section; an inner tubular section adapted to be connected to the pipe in use, said inner tubular section being nested at least partially within said outer tubular section; and an access aperture located in said inner tubular section; wherein the outer tubular section is adapted to cover the access aperture in use and the inner and outer tubular sections are adapted such that relative movement between the inner and outer tubular sections is possible in order to cover or uncover the access aperture. This provides the advantage that the access aperture can easily be opened or closed without the use of bolts, screws or similar fixing elements. As described below, notches may simply be provided which locate when the fitting is either open or closed; however this is not essential. Because screws, bolts or similar fixings are not required the appearance of the access pipe is improved and the problem of losing the screws, bolts or similar fixings in use is removed. Also, because the outer tubular section is always located around the inner tubular section, there is no possibility of losing the access cover and no problem of storing the access cover during maintenance work.

Preferably said relative movement comprises sliding movement substantially parallel to the axis of the tubular sections. This provides the advantage that the access cover is suitable for use with rainwater and other pipes of any cross-section. For example, rainwater pipes of square cross-section can be used.

Preferably, both ends of said inner tubular section are adapted to connect to the pipe in use and this is achieved by providing the inner tubular section with a socket adapted to accept the end of a section of the pipe in use. The inner tubular section is then also provided with a spigot adapted to be inserted into the end of a section of the pipe in use. In this way a simple and effective way to connect the access pipe to a rainwater pipe or waste pipe is achieved.

Preferably, the inner tubular section is arranged with respect to the outer tubular section such that contact between the edges of said access aperture and the outer tubular section is minimised. This provides the advantage that as liquid flows through the inner tubular section a suction force or vacuum is created which acts to draw water clear of the area between the inner and outer tubular sections. This helps to prevent liquid such as water from passing over the rim of the access aperture and between the inner and outer tubular sections. In this way it is not essential to provide a seal between the inner and outer tubular sections.

Advantageously an elastomeric seal is located substantially around the access aperture. This ensures that a liquid tight seal is obtained such that in use liquid flowing through the rainwater pipe, waste pipe or other pipe does not seep out of the access aperture. However, it is not essential for a seal to be provided. Preferably said inner tubular section comprises a ledge extending substantially around the inner tubular section and adapted such that the outer tubular section rests against the ledge in use. This ensures that the outer tubular section does not move away from the access aperture in use unless an operator lifts the outer tubular section away from the ledge. It is also preferred that said inner tubular section comprises a recess extending substantially around the inner tubular section and adapted to receive a support clip in use. In this way a support clip can easily be used in conjunction with the access cover in order to fix the access pipe to a support such as a wall.

In another embodiment of the present invention said relative movement comprises rotation substantially about the axis of the tubular sections. Also, a second access aperture is provided in said outer tubular section. This provides the advantage that a simple rotational movement of the inner or outer tubular section is enough to open or close the access aperture.

Preferably, in this second embodiment, one end of said inner tubular section is adapted to connect to a portion of the pipe in use. Also one end of said outer tubular section is adapted to connect to a portion of the pipe in use. Brief description of the drawings

Figure 1 is a part sectional view of an inner tubular section of an access cover.

Figure 2 is a plan view of an outer tubular section of an access cover that is suitable for use with the tubular section of Figure 1.

Figure 3 is a longitudinal cross section through an access cover that has an inner tubular section as shown in Figure 1 and an outer tubular section as shown in Figure

2 and that is connected to a rainwater pipe.

Figure 4 is a longitudinal cross section through another embodiment of an access cover which is connected to a rainwater pipe.

Figure 5 is a plan view of another example of an access cover which is connected to a rainwater pipe.

Figure 6 is a longitudinal cross section through the access cover of Figure 5.

Figures 7a is a longitudinal cross section through an inner tubular section. Figure 7b is a plan view of an outer tubular section that is nested around the inner tubular section of Figure 7a.

Figure 7c is a longitudinal cross section through the inner tubular section of Figure

7a where that inner tubular section has been rotated 90 degrees about its longitudinal axis. Figure 7d is a longitudinal cross section through the outer tubular section of Figure

7b where the outer tubular section is orientated to correspond with the inner tubular section of Figure 7c.

Figure 8a is a plan view of the inner tubular section of Figure 7a and 7b.

Figure 8b is a longitudinal cross section through the outer tubular section of Figures 7b and 7d. Figure 9 is a cross section through the inner and outer tubular sections of Figures 7 and 8 showing these nested together in use.

Figure 10 is a longitudinal cross section through the inner and outer tubular sections of Figure 9. Figure 1 1a shows an example of an assembled access cover.

Figure 11 b is a longitudinal cross section through an inner tubular section.

Figure 11c is a longitudinal cross section through an outer tubular section.

Figure 11d is a cross section through the outer tubular section of Figure 1 1c taken along the line A-A.

Detailed description of the invention

Embodiments of the present invention are described below by way of example only. These examples represent the best ways of putting the invention into practice that are currently known to the Applicant although they are not the only ways in which this could be achieved.

The term "down pipe" is used to refer to any type of pipe through which liquid flows under gravity, for example, a rainwater pipe and a domestic waste pipe.

The term "support clip" is used to refer to any type of fixing means that allows an access pipe to be supported and fixed to a support such as a wall. Figure 3 shows a first type of access cover that is connected to a rainwater pipe 10, 11 or other similar pipe. The access cover comprises an outer tubular section 1 and an inner tubular section 2. Part of the inner tubular section 2 is nested within the outer tubular section 1 so that relative rotational motion is possible. That is the outer tubular section 1 is arranged to be able to rotate about the inner tubular section 2 and vice versa. Alternatively, one of the tubular sections 1 , 2 may be fixed whilst the other tubular section is able to rotate about or within the fixed tubular section.

In this example, an access aperture 3 is provided in both the inner tubular section 2 and the outer tubular section 1. Figure 2 shows a possible form for the outer tubular section 2. Here the access aperture is elliptical in shape with the longer axis of the ellipse substantially parallel with the axis of the tubular section 2.

One end of the outer tubular section 2 is provided with a spigot 5 which is a portion of the outer tube that has a smaller diameter than the part containing the aperture 3.

The spigot 5 is shaped and sized to fit inside a section of rainwater pipe or other pipe that the access cover is to be used for so that water is substantially prevented from running from inside the pipe to the outside of the pipe. Because of the arrangement of the joint back flow of liquid in the pipe is prevented and this stops liquid from passing from the inside to the outside of the pipe via the joint. This complies with existing rainwater performance requirements. At the region where the diameter of the outer tubular section changes to form the spigot 5 a shoulder 16 is formed.

A wall clip location slot 7 is provided around the outer tubular section just above the spigot 5. This slot or recess 7 may be formed by two ridges which are spaced apart slightly to form a channel between the ridges as shown in figure 2. Alternatively, the slot 7 may be a channel set into the body of the outer tubular section 1. The slot 7 is used to locate a wall clip that can be used to attach the access cover to a wall or other support.

An alignment mark 4 is also provided on the outer tubular section 1. This alignment mark may be an indentation in the outer tubular section itself or may be a coloured line or other sign. Figure 1 shows an inner tubular section 2 for the first embodiment of the invention as described above. The inner tubular section 2 also has an access aperture 3 that is preferably, but not essentially, formed with the same shape as the access aperture in the outer tubular section 1. One end of the inner tubular section 2 is provided with a socket 6 that is shaped and sized to receive an end of a pipe such as a rainwater pipe that the access cover is to be used for. The socket 6 comprises a region of the inner tubular section that has a slightly wider diameter than the rest of the inner tubular section. As a result a shoulder 14 is formed on the outside of the inner tubular section 2. An alignment mark 4 is also provided on the inner tubular section 2. In the example shown in figure 1 the alignment mark 4 comprises a protrusion that is shaped to correspond with an indentation in the outer tubular section. However, this is not essential. The alignment mark could be any type of sign.

An identification mark 9 can be displayed on the inner tubular section, on the socket portion. This identification mark 9 enables a maintenance operator to locate the access cover when it is in place on a pipe such as a rainwater pipe. The identification mark can be placed anywhere on the access cover that remains visible throughout use of the access cover. The identification mark 9 is provided on a display area where information about the product name and number may be displayed. It is also possible to provide another display area 17 for displaying information about how to operate the access cover, for example, which direction to rotate or slide the access cover in order to open the access aperture.

Figure 3 shows how the access cover according to the first embodiment is assembled. The socket 6 of the inner tubular section 2 is placed over the end of a first or upper portion of rainwater pipe, waste pipe or other suitable pipe 11. The ultimate direction of flow of liquid through the pipe is indicated by the arrow in figure 3. The outer tubular section 1 is then nested around the inner tubular section 2. This is done by sleeving the end of the outer tubular section that is opposite the spigot 5 over the end of the inner tubular section that is opposite the socket 6. The end of the outer tubular section that is opposite the spigot 5 eventually abuts the shoulder 14 in the inner tubular section.

The spigot 5 on the end of the outer tubular section 1 is then inserted into another section of the rainwater pipe 10 or other suitable pipe until the rainwater pipe 10 abuts the shoulder 16 in the outer tubular section 1. In this way an effectively continuous section of rainwater or other pipe is formed that is substantially liquid tight. The upper section of rainwater pipe 1 1 , the inner and outer tubular sections are held together using a friction fit between these parts and also by gravity because the overall pipe is always arranged with a fall so that liquid flows in the direction of the arrow in figure 3, i.e. from the socket 6 towards the spigot 5. However, the lower section of rainwater pipe 10 could be gradually forced away from the access cover by gravity. This problem may be solved by using any conventional fixing means to hold the lower section of rainwater pipe 10 in place. For example, the lower section of rainwater pipe 10 may be held in place using brackets that are attached to a support surface such as the outer wall of a house. In the case that the outer tubular section 1 is intended to rotate care must be taken not to prevent this.

During maintenance, the outer tubular section 1 and the inner tubular section 2 are rotated with respect to one another until the access apertures 3 on each tubular section are in alignment. An operator is then able to access the pipe via the apertures 3. In order to close the access apertures 3 further relative rotation of the tubular sections is carried out until the apertures 3 are out of alignment. It is possible for one of the tubular sections 1 , 2 to be fixed whilst the other is able to rotate. Alternatively, both sections may be rotatable. A handle may be provided on the outer tubular section to assist the rotation. No screws or bolts are required for the access cover and as shown in figure 3 a substantially continuous outer surface is created on the overall rainwater or other pipe. This significantly improves the appearance of the pipe.

Figures 7A to 7D and Figures 8 to 10 illustrate another example of this first type of access cover. In this example the diameter of the main body of the inner tubular section is arranged to be slightly smaller than the diameter of the rainwater or other pipe that is to be received by socket 6 in the top of the inner tubular section. The inner tubular section illustrated in Figure 7A therefore has a sloping region 18 at the transition between the socket portion 6 and the main body of the inner tubular section 2. This sloping region 18 helps to channel liquid from a rainwater pipe connected into socket 6 into the main body of the inner tubular section 2. By using a sloping region 6 in this way any build up or dirt of other matter on the sloping region is reduced because this matter is washed away by the flow of liquid.

The inner tubular section 2 also has a ridge or projection 19 which extends from the wall of the inner tubular section away from the centre of the inner tubular section. This projection 19 extends in a ring around the inner tubular section (as shown in Figure 8A) and is located at the point where the sloping region 18 joins the lower part of the inner tubular section 2. The projection 19 does not extend away from the inner tubular section 2 further than the shoulder 14 extends.

At the base of the inner tubular section, i.e. the end furthest from the socket 6, the thickness of the inner tubular section wall is reduced creating a thin wall section 20 around the base (see Figure 8A). Around the edge or mouth of the aperture 3 in the inner tubular section 2 a projection 21 is provided as shown in Figure 7C and Figure 8A. This projection 21 extends away from the inner tubular section by the same amount as projection 19.

Figure 9 also illustrates this projection 21 and shows how it does not extend at a normal to the surface of the inner tubular section but rather slopes away from this.

Another projection 22 is provided on the inner tubular section 2. This projection has the same shape as the projection 21 , that is the shape of the perimeter of the access aperture 3. This projection is also illustrated in Figure 9 and

Figure 7C The projection 22 extends away from the inner tubular section by the same amount as projection 19 and also is angled away from the inner tubular section surface in the same way as projection 21. Projection 22 is positioned approximately 180° from projection 21 on the surface of the inner tubular section.

These positions are intended to represent the open and closed positions of the access cover as explained in more detail below.

Figure 7B illustrates an outer tubular section 1 with an aperture 3 that corresponds to that of the inner tubular section 2. In Figure 7B the outer tubular section is shown in place over the inner tubular section of Figure 7A with the socket

6 of the inner tubular section 2 being visible. Identification mark 9 and display area

17 are illustrated as described above.

Figure 7D shows a cross section through an outer tubular section 2 for use with the inner tubular section of Figure 7A and 7C A spigot 5 is provided at the base of the outer tubular section 1 and a shoulder 16 is created on the inside of the outer tubular section 1 in the region where the spigot begins.

Figure 10 and Figure 9 illustrate the inner 2 and outer 1 tubular sections when these are nested together. From this it can be seen that the main body of the inner tubular section 2 is of significantly smaller diameter than the outer tubular body 1. Thus when the inner and outer tubular sections are nested together a gap 23 is created between them. The size of this gap is arranged to be the same as the extent of the projections 19, 21 , 22 on the inner tubular section. By doing this, the projections 19, 21 , 22 function as spacers to ensure that the inner tubular section is held away from the inner surface of the outer tubular section 1. That is, the projections 19, 21 , 22 from the inner tubular section 2 contact the inner surface of the outer tubular section when the tubular sections are nested. Also, the projection 21 , which forms a ring around the aperture 3 on the inner tubular section 2, contacts the outer tubular section 2 and effectively acts as a seal between the inner and outer tubular sections. The projection 22 also acts in this way as described below.

The thin wall section 20 around the base of the inner tubular section 2 is positioned such that when the inner and outer tubular sections are nested together the thin wall section 20 rests against the shoulder 16 on the inner surface of the outer tubular section. In this the shoulder 16 is effectively covered so that debris does not collect against it.

The mode of operation of the access cover is the same as for the first example described above. However, the design of the present example is particularly advantageous because the possibility of liquid seeping out between the inner and outer tubular sections is reduced. In the open position, as illustrated in Figure 10, the projection 21 around the mouth of the access aperture 3 on the inner tubular section 2 contacts the edge of the access aperture 3 on the outer tubular section 1. This creates a seal between the two tubular sections and ensures that the clearance space or gap 23 between the inner and outer tubular sections is not visible.

In the open position the other projection 22 contacts the inner wall of the outer tubular section as illustrated in Figure 10 and acts as a spacer as described above. In order to close the access cover the inner tubular section may be fixed whilst the outer tubular section is rotated through 180°. In this closed position, the projection 22 on the inner tubular section contacts the edge of the access aperture 3 in the outer tubular section 1. This creates a seal and means that the clearance gap 23 between the inner and outer tubular sections is not visible. The projection 21 also contacts the inner surface of the outer tubular section 1 and acts as a seal and spacer as mentioned above. It is also possible to rotate the inner tubular section whilst the outer tubular section remains fixed. Any other rotations can be used to create the required relative movement between the inner and outer tubular sections. Regions A and B are indicated in Figure 10. These regions occur where the base of the inner tubular section 2 contacts the outer tubular section 1. Liquid flowing through the access fitting could seep into regions A and B and leak out between the inner and outer tubular sections. However the arrangement of the inner and outer tubular sections is such that as liquid flows through the access fitting in the direction of arrow C, any liquid in regions A and B is forced down into the pipe and away from regions A and B. That is, as liquid flows down through the access fitting it creates an effective suction force which draws liquid away from regions between the inner and outer tubular sections.

Another problem is that liquid in the access fitting can be drawn by capillary action into regions (such as regions A and B) between the inner and outer tubular sections. By providing a clearance region or gap 3 between the inner and outer tubular sections this problem is reduced. The presence of the clearance region 3 acts to reduce capillary action. Also, because the contact area between the inner and outer tubular sections is kept to a minimum there is a reduced possibility of liquid being drawn into this region by capillary action. It is also possible to provide seals around the inner tubular section 2 in order to seal the region between the inner and outer tubular sections. However, this is not essential and is typically only required for special installations. These seals may be provided around the inner tubular section 2 above and below the access aperture 3. For example, just below the ring projection 19 as indicated by reference numeral 24 in Figure 7C and just below one of the projections 22 as indicated by reference numeral 25 in Figure 7C

In the example described above the inner tubular section 2 has a socket 6 for connecting to a rainwater pipe and the outer tubular section 1 has a spigot for connecting to another section of rainwater pipe. However, it is not essential to provide means for connecting the access fitting to rainwater pipes in this way. For example, the inner tubular section may have means provided at each of its ends for connecting to rainwater pipes whilst the outer tubular section has no such means. Figure 4 shows an alternative embodiment of the invention that is suitable for use with rainwater pipes of square cross-section as well as circular and other shapes of cross-section. In this case only one access aperture 3 is provided and this is located on the inner tubular section. The outer tubular section is slidable in a direction substantially parallel to the axis of the tubular sections so that the access aperture 3 can be covered or uncovered.

In this embodiment the inner tubular section is provided with a socket 6 at one end and a spigot 13 at the other end. The socket 6 is used to join the inner tubular section 2 to an upper section of rainwater pipe 11 as in the first embodiment.

The spigot 13 is used to join the inner tubular section 2 to a lower section of rainwater pipe 10 in a similar way as for the spigot 5 on the outer tubular section in the first embodiment. An access aperture 3 is provided in the inner tubular section 2, preferably towards the spigot end of that section. A ledge 12 is provided on the outside of the inner tubular section also towards the spigot end of that section. This ledge 12 is adapted to support the outer tubular section 1. That is, the outer tubular section 1 is nested around the inner tubular section and rests against the ledge 12. When the outer tubular section 1 is resting on the ledge 12 it extends over the access aperture 3 and closes this. In order to open or uncover the access aperture 3 the outer tubular section 1 is slid upwards away from the aperture 3 and eventually exposing this. The outer tubular section 1 may be held in the "open" position away from the aperture 3 using a friction fit or any other suitable means such as a snap fit or a latch.

In this embodiment alignment marks and an elastomeric seal can also be provided as well as other suitable features from the first embodiment.

Figures 5 and 6 illustrate another example of this second type of access cover which involves longitudinal relative motion between the tubular sections rather than rotational motion. Figure 5 shows an access cover fitting in the closed position and Figure 6 is a cross-section of the access cover of Figure 5 when this is in the open configuration.

In this example the inner tubular section 2 is provided with an annular protrusion 25 spaced slightly away from the socket 6. This protrusion 25 acts as a stop to limit the travel of the outer tubular section 1 when in the open position.

However, it is not essential to use the protrusion 25 in this way. The base of the socket 6 can also be used to perform the stop function.

In this example, the end of the inner tubular section 2 furthest from the socket 6 does not carry a ledge 12 or other means for holding the outer tubular section in place in the closed position. Instead the section of rainwater or other pipe 10 that the inner tubular section 2 is joined to is provided with a modified socket 26.

The socket 26 is widened at its top to a diameter that is slightly greater than the spigot 13 of the inner tubular section 2. This creates a channel 27 between the top of the socket 26 and the inner tubular section 2 into which the end of the outer tubular section fits in the closed position. The socket 26 is sized and shaped so that the channel 27 is wide enough to accommodate the outer tubular section and form a liquid tight seal.

At the base of the socket 26 a support clip channel 7 may be provided although this is not essential. This support clip location may be formed in any suitable manner as described above.

As shown in Figure 6 the access aperture 3 may be located such that it is partially occluded by the socket 26 on the top of the rainwater pipe or other pipe 10.

When the access aperture is closed, any liquid that seeps out of the access aperture collects in the socket 26 and gradually drains back into the access fitting. Also, by positioning the access aperture 3 in this way the overall length of the access fitting is reduced. However it is not essential to locate the access aperture in this way. The access aperture 3 can be located so that it is not covered by the socket 26 in use.

It is also possible to combine the features of the two embodiments described above by creating an access cover where either rotation or sliding motion of the inner and outer tubular sections can be used to cover and uncover the access aperture(s).

In another embodiment the access cover or fitting is arranged to operate with a pipe of square (or any other suitable shape) cross-section. In this case, parts of the access cover or fitting also have a square cross-section in order that the appearance of the pipe is not disrupted. Figures 1 1a to 1 1c illustrate this. Figure 11a shows an access cover 110 in its assembled state and with an access aperture 111 which is uncovered. As described above the access cover 110 comprises an inner and an outer tubular section and these are illustrated in Figures 11 b and 11 c respectively. The arrows between Figure 1 1 b and Figure 11 c indicate how the inner tubular section 11 b is inserted into the outer tubular section 11c in order to assemble the access cover 110. In the assembled state (Figure 11a) the shape of the cross section of the access cover 1 10 is substantially the same along the length of the access cover 110.

The inner tubular section has a socket 112 which has a substantially square cross-section and is arranged to receive the end of a piece of down pipe that is also of square cross-section. Because of this socket 112 of substantially square cross- section, the inner tubular section is fixed when it is connected to the down pipe and is unable to rotate about its longitudinal axis.

The inner tubular section has a tubular body 113 with a substantially circular cross-section. An access aperture 114 is provided in this body 113.

The outer tubular section is illustrated in Figure 11 c and comprises a spigot 115 which has a substantially circular cross-section and a tubular body 116 connected to the spigot 115. The outer circumference of the tubular body 1 16 has a square cross section whilst the inner surface of the tubular body 116 is arranged to receive the tubular body 113 of the inner tubular section. This may be achieved in several different ways. For example, the square outer tubular body 116 may have a pipe 117 of circular cross section inside it. This pipe 117 is sized and shaped to receive the inner tubular section of Figure 11b and has an access aperture 118 as does the square outer tubular body (see access aperture 119). Once the inner tubular section (see Figure 11b) is placed within the outer tubular section (see figure 11c) the inner tubular section is fixed to the down pipe whilst the outer tubular section is able to rotate about its longitudinal axis. This is because the outer tubular section has a spigot 115 which is of circular cross-section and is able to rotate within any down pipe in which it is inserted. If the spigot 1 15 is inserted into a down pipe which has a square cross-section, that down pipe is adapted in order to accommodate the spigot shape. For example, in the same manner that the outer tubular section body 116 is adapted to accommodate the tubular body of the inner tubular section (Figure 11b).

During installation the inner body (Figure 11 b) is positioned with the access aperture facing away from any support surface (such as a wall down which the rain water pipe runs) because this part of the fitting is fixed in use and cannot rotate.

Instead of using a pipe of circular cross section 117 inside the outer tubular section body 116 it is also possible to use spacers or guides attached to the inner surface of the outer tubular section body 116. These spacers or guides enable the inner tubular section body 113 to be correctly positioned within the outer tubular section body 116.

Figure 11d is a cross-section through the outer tubular section body 116. This shows the access aperture 118 in the outer tubular section and the pipe of substantially circular cross section 117 inside the outer tubular section body 116. This pipe has an access aperture 119 and in this example, parts of the outer tubular section body 116 form part of the pipe 117.

In another embodiment the outer tubular section and the inner tubular section are both of square cross-section (or any other suitable shape of cross- section). In this case, the outer tubular section slides in a direction parallel to the longitudinal axis of the nested tubular sections in order to cover or uncover the access aperture.

Claims

1. An access cover for providing access to a pipe in use comprising: an outer tubular section; an inner tubular section adapted to be connected to the pipe in use, said inner tubular section being nested at least partially within said outer tubular section; and an access aperture located in said inner tubular section; wherein the outer tubular section is adapted to cover the access aperture in use and the inner and outer tubular sections are adapted such that relative movement between the inner and outer tubular sections is possible in order to cover or uncover the access aperture.

2. An access cover as claimed in claim 1 wherein said relative movement comprises sliding movement substantially parallel to the axis of the tubular sections.

3. An access cover as claimed in claim 1 or claim 2 wherein both ends of said inner tubular section are adapted to connect to the pipe in use.

4. An access cover as claimed in any preceding claim wherein said inner tubular section comprises a socket adapted to accept the end of a section of the pipe in use.

5. An access cover as claimed in any preceding claim wherein the inner tubular section is arranged with respect to the outer tubular section such that contact between the edges of said access aperture and the outer tubular section is minimised.

6. An access cover as claimed in any preceding claim wherein the diameter of the inner tubular section is smaller than that of the outer tubular section such that in use, when the inner tubular section is nested within the outer tubular section a space is created between the inner and outer tubular sections such that liquid is substantially prevented from being drawn into this space by capillary action.

7. An access cover as claimed in any preceding claim wherein said inner tubular section comprises a spigot adapted to be inserted into the end of a section of the pipe in use.

8. An access cover as claimed in any preceding claim which further comprises an elastomeric seal located substantially around the access aperture.

9. An access cover as claimed in any preceding claim wherein said inner tubular section comprises a ledge extending substantially around the inner tubular section and adapted such that the outer tubular section rests against the ledge in use.

10. An access cover as claimed in any preceding claim wherein said inner tubular section comprises a recess extending substantially around the inner tubular section and adapted to receive a support clip in use.

11. An access cover as claimed in claim 1 wherein said relative movement comprises rotation substantially about the axis of the tubular sections.

12. An access cover as claimed in claim 11 wherein a second access aperture is provided in said outer tubular section.

13. An access cover as claimed in claim 1 1 or claim 12 wherein one end of said inner tubular section is adapted to connect to a portion of the pipe in use.

14. An access cover as claimed in claim 13 wherein one end of said outer tubular section is adapted to connect to a portion of the pipe in use.

15. An access cover as claimed in any of claims 11 to 14 wherein said outer tubular section comprises a recess extending substantially around the outer tubular section and adapted to receive a support clip in use.

16. An access cover as claimed in any of claims 1 1 to 15 which further comprises an elastomeric seal located substantially around the first access aperture on the inner tubular section.

17. An access cover as claimed in any of claims 11 to 16 wherein said inner and outer tubular sections each comprise an alignment mark for aligning the inner and outer tubular sections with respect to one another.

18. An access cover as claimed in any preceding claim wherein said access aperture is elliptical.

19. An access cover as claimed in any preceding claim wherein at least part of the outer tubular section and at least part of the inner tubular section have a cross- section of substantially polygonal shape.

20. An access cover as claimed in claim 19 wherein the inner tubular section has a socket of substantially polygonal cross-section.

21. An access cover as claimed in claim 19 or claim 20 wherein the outer tubular section has a tubular body with an external circumference of substantially polygonal cross-section and where the inner surface of the tubular body is arranged to receive a tubular section of substantially circular cross-section.

22. An access cover as claimed in any of claims 19 to 21 wherein the outer tubular section has a spigot of substantially circular cross-section.