GB2580476A

GB2580476A - Electronics enclosure and system

Info

Publication number: GB2580476A
Application number: GB1915365.9A
Authority: GB
Inventors: Atkinson Neil
Original assignee: Siemens Mobility Ltd
Current assignee: Siemens Mobility Ltd
Priority date: 2018-11-07
Filing date: 2019-10-23
Publication date: 2020-07-22
Anticipated expiration: 2039-10-23
Also published as: GB201915365D0; GB201818153D0; GB2580476B

Abstract

An underground electronics equipment enclosure comprises a bell chamber 203 having side walls 207 and top wall 205, but an optionally open bottom, creating an internal space 247 for housing an electronics component 131. The bell chamber provides an air pocket to protect the equipment, such as from flooding. The open bottom may have a lid 227. The bell chamber 103 has one or more fixing points 231 to allow removable mounting of electronics 219 inside chamber. The fixing points may be raised 215, preferably as ribs with a grid array of fixing holes (see figure 7). The chamber maybe located under a cover (101 figs 1-4 ) of a man-hole or inspection pit, and the chamber and cover may be fixed together. A cable 40 leads from the component 219 to a sealed hermetic coupler 41, preferably a resin cable joint, either located in the chamber 203 or in the vicinity. The hermetic coupler provides a hermetic break in the cable so that the cable cannot provide a continuous air passage out of the chamber, which could otherwise reduce the air pocket.

Description

ELECTRONICS ENCLOSURE AND SYSTEM

The present disclosure relates to an underground electronics enclosure and system, and in particular to an underground electronics enclosure that forms a bell chamber to prevent or reduce the ingress of water into the enclosure.

Background

Electronics equipment is generally installed above ground in weatherproof enclosures.

Due to above ground space restrictions, safety, and security it is desirable to install the electronics equipment below ground. The weatherproof enclosures used in above ground installations are generally not sufficient for use underground, especially in areas with a high water table or which are prone to flooding. An underground enclosure may be partly or wholly submerged at times, and a weatherproof enclosure would not be able to prevent the ingress of water into the enclosure under these circumstances.

Some existing underground electronics installations require that the electronics equipment is provided in a fully potted enclosure to protect against the ingress of water. Potting requires filling the enclosure with a compound such as a resin or silicon. A problem with potting is that it is difficult to subsequently enter the enclosure to perform service or maintenance operations on the electronics equipment, or to modify the electronics equipment by removing or adding equipment. Instead, in case of an electronics failure or an upgrade or modification, the entire electronics enclosure would need to be replaced.

Some existing underground electronics installations require that the electronics equipment is housed in a waterproof enclosure that prevents the ingress of water into the electronics equipment. Such waterproof enclosures are typically complex, costly and large. Due to the size of the waterproof enclosures, in particular, underground enclosures typically need to be installed in a custom dug pit and are unable to make use of existing service pits (e.g. manholes). Extensive engineering work may be required to dig the pit, and it may be disruptive and expensive, especially if the pit is to be dug in a popular or sensitive area.

Summary

According to the present disclosure there is provided an apparatus and system as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and the description which follows.

According to a first aspect of the invention, there is provided an underground electronics enclosure. The enclosure comprises a bell chamber having side and top walls and defining an internal space for housing an electronics component. The bell chamber comprises at least one fixing point to allow the electronics component to be removably mounted in the bell chamber. The enclosure further comprises a cable to electrically couple the electronics component to equipment outside the enclosure. The cable comprises a hermetically sealed coupler located within the enclosure, or in the vicinity of the enclosure.

The coupler couples two parts of cable together to provide electrical continuity and mechanical separation between the electronics component and the external equipment, so that air cannot escape from the chamber through the cabling. The cable is connected to the electronic component and extends out of the bell chamber.

The connection of the cable is made by providing a break in the cable which results in two cable ends at the location of the cable break. The two cable ends are joined together by a cable joint, which is a sealed cable joint.

The underground electronics enclosure comprises a bell chamber. The bell chamber helps prevent ingress of water into the enclosure and thus helps protect the electronics component against water damage. In particular, when positioned underground in a duct, the water level within the duct may rise due to heavy rain, or flooding, for example. The air pressure within the bell chamber prevents ingress of water due to the rise in water level. In particular, the rise in water level causes the air pressure within the bell chamber to increase which prevents water ingress.

However, air in the chamber may leak out through the voids in the electrical cables connected between the electronics and external equipment and so reduce the effectiveness of the air pressure in keeping water out of the chamber. The present invention addresses this problem by providing a hermetically sealed coupler providing an electrical connection whereby electrical continuity is maintained, but a physical block in the cable so that mechanical continuity is prevented. This stops the flow of air down the cabling so that the necessary air buffer in the bell chamber to prevent water from rising up to the level at which the electronics are installed.

The at least one fixing point allows for the electronics component to be mounted and/or removed from the bell chamber. The term "fixing point" refers generally to a feature that provides a fixing point for mounting an electronics component. This provides a configurable system, as the end user can add and remove electronics components as they please.

The electronics component disposed within the bell chamber does not need to be potted or provided within a waterproof enclosure. The only part that needs a fully air and watertight seal is the cable coupler, but the coupler is connected to another section of cable, so that connecting and disconnecting the electronics component from the cable has no effect on the cable coupler seal. As such, the present invention enables electronics components to be serviced or replaced more easily than existing approaches, yet still keeps the electronics component water tight without the need for a large and expensive waterproof enclosure. The protection against water is provided by a simple bell chamber.

In use, the underground electronics enclosure may be positioned in a hole in the ground. The underground electronics enclosure may be aligned with a vertical axis of the hole such that a bottom end of the bell chamber points downward into the duct. As the water level rises, the top wall of the bell chamber prevents air from escaping the bell chamber which causes the air pressure to increase.

The at least one fixing point may be a recess for receiving a fixing such as a screw, nut, or stud for mounting the electronics component in place. The at least one fixing point may also, for example, be a stud to which an electronics component may be mounted. Of course, the present invention is not limited to these particular examples of fixing points. Other examples of fixing points are within the scope of the present invention, such as clips and push fit fittings.

The bell chamber may comprise a plurality of fixing points. This means that a plurality of fixing points may be provided. Significantly, a plurality of fixing points may provide more options for mounting the electronics component. For example, the electronics component may be able to be mounted in different positions by using different ones of the fixing points. For example, a plurality of electronics component may be able to be mounted at the same time using the plurality of fixing points.

The at least one fixing point may be provided on, or in the vicinity of, the top wall, the side wall, or both the top wall and the side wall.

The at least one fixing point may be provided on, or in the vicinity of, an inner surface of the top wall of the bell chamber facing the internal space. A plurality of fixing points may be provided on, or in the vicinity of, the inner surface of the top wall of the bell chamber.

Any number of fixing points may be provided as desired by the skilled person. The number of fixing points may be selected based on, for example, the size of the bell chamber. In some examples, 5 or more, 10 or more, 20 or more, 30 or more, 40 or more, 50 or more, or even 100 or more fixing points may be provided.

The plurality of fixing points may be arranged in any way. In one example, particularly suited to bell chambers having rectangular shaped top walls, the plurality of fixing points may be arranged in an array comprising rows and columns. The array may comprise a number N of rows, and a number M of columns. N and M may be 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, or 20 or more. N may be equal to M. The at least one fixing point may be provided on the inner surface of the top wall of the bell chamber. A plurality of fixing points may be provided on the inner surface of the top wall. The fixing point or points may be recesses in the top wall. The recesses may not extend through the whole thickness of the top wall.

The inner surface of the top wall may comprise a spacer. The spacer may comprise the at least one fixing point. The spacer acts to space the electronic component away from the top wall so as to improve heat dissipation for the electronic component. A plurality of spacers may be provided and each may comprise one or more fixing points. The spacers may be in the form of a protrusion extending downwardly from the top wall of the bell chamber.

The inner surface of the top wall may define at least one raised section and at least one lowered section. The at least one fixing point may be provided on the at least one raised section. The inner surface of the top wall may have a crenellated structure that defines a plurality of raised and lowered sections.

The at least one raised section may extend between the side wall of the bell chamber. If the bell chamber is a box-like structure there may be opposed side walls, and the raised section may extend between the opposed side walls. The raised section may extend diagonally between adjacent side walls. The plurality of fixing points are provided spaced apart along the at least one raised section.

The bell chamber may comprise a mounting structure coupled to the top wall and/or the side wall of the bell chamber. The mounting structure may provide the at least one fixing point. In other words, the at least one fixing point may be provided on a mounting structure such as a mounting plate. The mounting structure may be coupled to the top wall of the bell chamber. The mounting structure may be releasably coupled to the top wall of the bell chamber. The mounting structure may be fixedly coupled to the top wall of the bell chamber. A plurality of fixing points may be provided on the mounting structure. The fixing point or points may be recesses in the mounting structure. The recesses may extend through the whole thickness of the mounting structure. The recesses may not extend through the whole thickness of the top wall.

The enclosure may further comprise an adapter structure such as an adapter plate. The adapter plate may be coupled, e.g. removably, to the at least one fixing point. The adapter plate may provide a surface for receiving the electronic component.

The top wall of the bell chamber may be attached, e.g. fixedly, to the side wall of the chamber. The top wall and the side wall may together form an integral, unitary, structure. That is, the top wall of the bell chamber may be integral with the side wall of the bell chamber.

The enclosure may comprise a cover. The cover may be coupled to an outer surface of the top wall of the bell chamber. The cover may be or may have the appearance of a service hole cover (e.g. a manhole cover). The cover may have treads or other raised features to reduce the risk of someone slipping or sliding on the cover. The cover may be integral with the top wall of the bell chamber. In other words, the top wall of the bell chamber may be the cover.

The enclosure may comprise a lid. The lid may be coupled to a bottom end of the bell chamber. The bottom end of the bell chamber may be open or at least partially open.

In other words, the bell chamber may not comprise a bottom wall or may comprise a partial bottom wall. The lid may be for covering all or part of the open bottom end of the bell chamber. The lid may be releasably attachable to the bell chamber. The lid may be beneficial in reducing moisture in the bell chamber and for keeping animals such as rodents and slugs away from the electronics components. It will be appreciated that the lid is not required to completely seal the bottom end of the bell chamber against the ingress of water. This functionality is provided by the bell chamber itself.

The lid may comprise an aperture for receiving a cable therethrough. The cable may be for connecting to the electronics component. The cable may be coupled to the lid so as to provide strain relief for the cable.

While the electronics component is not required to be potted, the electronics equipment may comprise some water protection so as to protect against dampness within the enclosure. The electronics component may be conformably coated. The electronics component may be provided in its own enclosure which may in turn be mounted to the bell chamber using the at least one fixing point.

The internal space may be for housing a plurality of electronics components.

The enclosure may form a service hole cover. A service hole may also be known as a manhole. The enclosure may be supported by a cover surround of the service hole. The enclosure may be lifted out of the service hole in one piece, for example.

The bell chamber may have a box shape.

The bell chamber may have a cylindrical shape.

The bell chamber may be formed from uPVC. The bell chamber may be formed from metal According to a second aspect of the invention, there is provided a system. The system comprises an underground electronics enclosure. The enclosure comprises a bell chamber having side and top walls and defining an internal space for housing an electronics component. The bell chamber comprises at least one fixing point to allow the electronics component to be removably mounted in the bell chamber. The system further comprises an electronics component mounted to the bell chamber via the at least one fixing point. The enclosure further comprises an electrical cable to electrically couple the electronics component to equipment outside the enclosure; wherein the cable comprises a hermetically sealed coupler located within the enclosure, or in the vicinity of the enclosure.

The present invention provides an underground electronics enclosure that does not require the electronics equipment to be fully potted or installed in a complex, or expensive, waterproof enclosure and an underground electronics enclosure that has a smaller profile.

The coupler provides electrical coupling between a first cable section connected to the electronics component and a second cable section connected to equipment outside the enclosure.

The cable connected to the electronic component via the coupler extends out of the bell chamber.

The coupler provides a break in the cable such that the cable is not a continuous length of cable. The break in the cable results in two cable ends at the location of the cable break which may be joined together by a cable joint. The hermetically sealed couple in the form of a cable joint prevents the passage of air from one of the cable ends to the other of the cable ends via the cable joint. A continuous length of cable provides a route for air to flow out of the bell chamber. This means that air can be lost from the bell chamber through the cable. Significantly, by breaking the cable (e.g. by cutting the cable) and joining the broken ends of the cable together with a cable joint, this continuous air passage is blocked. Significantly, this helps prevent the air pressure decreasing in the bell chamber, which would reduce the effectiveness of the bell chamber in preventing water ingress. The cable joint is a sealed cable joint which provides enhanced protection against air escaping through the cable joint. The sealed cable joint may be a resin filled cable joint.

Brief Description of the Drawings

Examples of the present disclosure will now be described with reference to the accompanying drawings, in which: Figure 1 shows an exploded section view of an example underground electronics enclosure according to aspects of the present invention; Figure 2 is a perspective view of the underground electronics enclosure shown in Figure 1; Figure 3 shows an assembled section view of the underground electronics enclosure shown in Figure 1; Figure 4 shows an assembled section view the underground electronics enclosure of Figure 1 positioned within a hole; Figure 5 shows an exploded section view of another example underground electronics enclosure according to aspects of the present invention; Figure 6 shows an assembled section view of the underground electronics enclosure shown in Figure 5; Figure 7 shows a detailed view of the underground electronics enclosure shown in Figure 5; Figures 8(a) shows an exploded view of another example underground electronics enclosure according to aspects of the present invention; Figure 8(b) shows a section view of part of the underground electronics enclosure of Figure 8(a); Figure 8(c) shows a section view of part of the underground electronics enclosure of Figure 8(a); Figure 9 shows an assembled section view of the underground electronics enclosure of Figure 8(a) positioned within a hole; and Figure 10 shows three underground electronics enclosures positioned within different holes in accordance with the present invention.

Detailed Description

Referring to Figure 1, there is shown an exploded, sectional, view of an underground electronics enclosure 100 according to the present invention. The underground electronics enclosure 100 is positionable within a hole 20. In this example, the hole 20 has a rectangular cross-section. A cover surround 30 is mounted in the hole 20 at a position towards the top of the hole 20. The cover surround 30 has a flange 33 extending around its inner perimeter for supporting the enclosure 100 within the hole 20.

The underground electronics enclosure 100 comprises a cover 101. The cover 101 has a rectangular shaped cross-section substantially matching the cross-section of the hole 20. When positioned in the hole 20, the lower surface 141 of the cover 101 rests on and is supported by the flange 33 of the cover surround 30. When in this supported position, the cover 101 may lie substantially flush with the ground surface 23. The upper surface 143 of the cover 101 comprises a plurality of raised features to reduce the risk of someone slipping or sliding on the cover 101.

The underground electronics enclosure 100 further comprises a bell chamber 103. The bell chamber 103 comprises a top wall 105, and side walls 107a, 107b that depend downwardly from the top wall 105. In this example, the top wall 105 has a rectangular cross-section, and four side walls 107a, 107b extend downwardly from the top wall 105 to define an internal space 147. The bottom end 109 of the bell chamber 103 is open. The bell chamber 103 is thus an open bottomed enclosure in the form of a rectangular box.

The bell chamber 103 is attachable to the cover 101. In this example, cover 101 comprises fixtures 111 in the form of studs 111 that depend from the bottom surface 141 of the cover 101. Features 129 extending outwardly from the top wall 105 of the bell chamber 103 are able to receive the studs. Fixings 113, such as nuts, are used to connect the bell chamber 103 to the cover 101 via the studs 111. The fixings may provide a removable coupling between the bell chamber 103 and the cover 101. The studs 111 may be an integral part of the cover 101 or may be otherwise attached to the cover 101. Once the bell chamber 103 is attached to the cover 101, the cover 101 overhangs the bell chamber 103 so that the cover 101 can rest on the flange 33 of the cover surround 30.

The enclosure 100 further comprises a mounting structure 115 in the form of a mounting plate 115. Electronics components may be attached to the mounting plate 115. The mounting plate 115 comprises fixing points that enable equipment to be attached to the mounting plate 115 in configurable, or variable, ways. In this example, the mounting plate 115 further comprises four adapter plates 117 that are connected to the fixing points and that extend downwardly from the bottom surface of the mounting plate 115. The adapter plates 117 serve as fixing points for electronics components and provide the benefit of increasing the surface area over which electronics components may be attached to the mounting plate 115. In this example two printed circuit boards (PCB) 119 are shown mounted to the adapter plates 117.

The mounting plate 115 is attachable to the bell chamber 103. In this example, the bell chamber 103 comprises fixing points 121 in the form of studs 121 that depend downwardly from the closed top end 105 of the bell chamber 103. Fixings 123, such as nuts, are used to connect the mounting plate 115 to the bell chamber 103 via the studs 121. The studs 121 in this example are an integral part of the bell chamber 103. Providing the studs 121 as integral components of the bell chamber is helpful in preventing air from escaping from the closed top wall 105 of the bell chamber 103.

The studs 121, in particular, may be moulded into the bell chamber 103. The studs 121 may also be used as fixing points for electronics components. That is, the mounting plate 115 may not be required and electronics component 119s may be releasably connected to the studs 121 extending from the top wall 105 of the bell chamber 103.

The enclosure 100 further comprises a lid 127. The lid 127 covers the open bottom end 109 of the bell chamber 103 so as to help to reduce moisture in the bell chamber 103 and to prevent animals such as rodents and slugs from entering the bell chamber 103. The lid 127 is not required to form a sealed barrier to prevent the ingress of water, as the bell chamber 103 itself provides the water protection function to protect the electronics components 119 from being submerged in water. The lid 127 is releasably coupled to the bell chamber 103, for example, by clips. While not shown in Figure 1, cables may pass through the lid 127 so as to connect to the electronics components 119 attached to the mounting plate 115. The cables may be attached to the lid, for example to provide strain relief.

Referring to Figure 2, there is shown a perspective, exploded view, of the underground electronics enclosure 100 shown in Figure 1. In Figure 2, it can be seen that the bell chamber 103 has a rectangular box shape. Further, it can be seen that the features 129 extend from all four sides of the top wall 105 of the bell chamber 103 for connecting the bell chamber 103 to the cover 101. The features 129 have cut-out portions for receiving the studs of the cover 101.

Figure 2 further shows the fixing points 131 of the mounting plate 115 for releasably attaching electronics components. The lying points 131 are arranged, in this example, into four rows where each row comprises four fixing points 131. In this example, the fixing points 131 are used to connect the adapter plates 117 to the mounting plate 115. This means that the adapter plates 117 are releasably attachable to the mounting plate 115. Electronics components may be connected directly to the fixing points 131 and the adapter plates 117 are not required in all embodiments.

Referring to Figure 3, there is shown an assembled view of the underground electronics enclosure 100 shown in Figures 1 and 2. The enclosure 100 is shown lifted out of the hole 20. The enclosure 100 may be lifted out of the hole 20, or placed into the hole 20, as a complete unit. This means that the enclosure 100 does not need to be disassembled, for example to remove it from the hole 20.

Figure 3 further shows that a cable 40 extends into the underground electronics enclosure 100 so as to connect to the electronics components attached to the mounting plate. It will be appreciated that more than one cable 40 may provided. The cable 40 extends into the pit 20 and passes through a duct 21. The cable 40 may be for powering the electronics components and/or for transmitting data to/from the electronics components.

In the example of Figure 3, the cable 40 is cut and the cut ends of the cable 40 are joined together with a cable joint 41. In this particular example, the cable joint 41 is a sealed cable joint 41, and in particular a resin filled cable joint 41. The breaking and re-joining of the cable 40 removes the continuous air passage present in the original cable. This is significant in reducing or preventing air escaping from the bell chamber through the cable 40. Without the breaking and re-joining of the cable 40, the escape of air may decrease the pressure within the bell chamber, and thus may decrease the effectiveness of the bell chamber in preventing water ingress into the electronics components of the enclosure 100. Further, the use of a sealed cable joint 41 and in particular a resin filled cable joint 41 is not required in all embodiments and other forms and ways of providing a hermetic seal when joining two ends of the cable 40 together may be used.

Referring to Figure 4, there is shown the underground electronics enclosure 100 of Figures 1, 2 and 3 positioned within the hole 20. The lower surface 141 of the cover 101 rests on the flange 33 of the cover surround 30 to support the enclosure 100 and hold the enclosure 100 in a fixed position. The top surface 143 is substantially flush with the ground surface 23. The bell chamber 103 is oriented vertically in the hole 20 with the closed top wall 105 positioned towards the top of the hole 20, and the open bottom end 109 of the bell chamber 103 positioned vertically downwards.

Figure 4 further shows that the cable 40 is connected to the electronics component 119. The cable 40 passes through the lid 127, extends into the hole 20 and passes through the duct 21. The cable 40 has been broken and re-joined with a hermetically sealed coupler, in this example, in the form of a cable joint 41, as discussed above, to prevent air escaping from the chamber, down the cable. The coupler in the examples of Figs.3 and 4 is located in the hole 20 which is typically filled with water, but alternatively, the coupler may be located within the internal space 147 of the chamber by having a shorter section of cable from the electronics component 119.

Figure 4 shows that the hole 20 is flooded with water 50. However, the air pressure within the bell chamber 103 prevents water ingress into the underground electronics enclosure 100 and, in particular, the electronics component 119. Figure 4 shows that while the water surrounds part of the side wall of the bell chamber, the water is not able to enter the internal space 147 of the bell chamber 103 due to the high air pressure within the bell chamber 103. The bell chamber 103 thus provides an effective means of preventing water damage of the electronics component 119 without requiring a complex and inflexible fully potted electronics enclosure or complex waterproof enclosure.

Referring to Figure 5, there is shown an exploded view of another example underground electronics enclosure 200 in accordance with aspects of the present invention.

The underground electronics enclosure 200 of this example does not comprise a separate cover on top of the top wall 205 of the bell chamber 203. Instead, the bell chamber 203 itself provides the functionality of the cover. In more detail, the bell chamber comprises a top wall 205 and downwardly depending side walls 207a, 207b to define an internal space 247 for housing electronics components. The top wall 205, and side walls 207a, and 207b are integrally formed and, in particular, are cast as a single unit. The top wall 205 over hangs the sidewalls 207a, 207b, so that the lower surface 251 of the top wall 205 may rest on the flange 33 of the cover surround 30.

The top surface 253 of the top wall 205 comprises raised features 255 to reduce the risk of someone slipping or sliding on the top surface 253 of the bell chamber 203. Like the example of Figures 1 to 4, the bell chamber 203 is in the form of a rectangular box 203 with an open bottom end 209.

The lower surface 25a of the top wall 205 comprises six raised sections 257 with lowered sections positioned between adjacent raised sections 257. This in effect, provides a crenellated structure on the lower surface 25a of the top wall. Fixing points 231 are provided on the raised sections 257. The fixing points 231 are recesses that extend part, but not all, of the way through the top wall 205. The use of raised and lowered sections is one particular example of how the fixing points 231 may be provided. Other forms of spacers may be used instead, so as to space the electronic component from the top wall 205 of the bell chamber 203.

Figure 5 shows that an electronics component 219 is mounted to the bell chamber 203 using the fixing points 231. In particular, fixings 233 are provided in the form of screws 233 or threaded studs to mount the electronics component 219 to the bell chamber 203. A cable 40 is connected to the electronics component 219. The cable 40 extends downwardly into the pit 20 and enters a duct 21. The cable 40 has been broken and rejoined with a hermetically sealed cable joint 41 so as to prevent air escaping from the bell chamber 203 through the cable 40.

The underground electronics enclosure 200 further comprises a lid 227 for covering the open bottom end 209 of the bell chamber 203. The lid 227 is releasably coupled to the bell chamber 203 by clips, for example. Figure 5 shows that the cable 40 passes through the lid 227 so as to connect to electronics components 119. The cable 40 may be attached to the lid 227 so as to provide strain relief, for example.

Referring to Figure 6, there is shown an assembled view of the underground electronics enclosure 200 of Figure 5. The enclosure 200 is shown lifted out of the hole 20. The enclosure 200 may be lifted out of the hole 20 or placed into the hole 20 as a complete unit. This means that the enclosure 200 does not need to be disassembled to remove it from the hole 20, for example.

Further, in the example of Figure 6, the sealed cable joint 41 is positioned within the internal space 247 of the bell chamber 203 rather than outside the bell chamber as shown in Figures 1 to 4. This is not required in all embodiments. That is, the sealed cable joint 41 may be positioned inside or outside the bell chamber 203.

Referring to Figure 7, there is shown a detailed view of the underside of the bell chamber 203. It can be seen that the six raised sections 257 extend between the opposed side walls 207a, 207b. Further, each of the raised sections 257 comprises six fixing points 231 that are arranged in a straight line and spaced apart along the length of the respective raised sections 257. The fixing points 231 are effectively provided in an array comprising six rows and six columns.

While Figures 5 to 7 show the fixing points 231 in the form of recesses. It will be appreciated that the fixing points 231 are not limited to this arrangement. The fixing points 231 could be studs, for example.

Referring to Figure 8(a), there is shown an exploded view of another example underground electronics enclosure 300 in accordance with an aspect of the present invention. The underground electronics enclosure 300 comprises a cover 301 and a cylindrical shaped bell chamber 303 having a top wall 305 and a side wall 307 with a circular cross-section. The bell chamber 303 defines an internal space for receiving electronics components 319a, 319b and has an open bottom end 309. The bell chamber 303 could be a plastic enclosure with a sealed end defining the top wall 305.

The bell chamber 303 could be formed of a piece of uPVC ducting. The bell chamber 303 could also be a metal enclosure with a sealed end defining the top wall 305.

Referring to Figure 8(b), there is shown a close-up of section c in Figure 8(a). Figure 8(b) shows an internal fixing point 331 in the form of a threaded stud 331 extending from the lower surface 351 of the top wall 305. A recess, or a plurality of recesses/studs may also be provided as fixing points.

Referring again to Figure 8(a), there is provided a mounting plate 317 that comprises a nut 361 that enables the mounting plate 317 to be screwed onto the threaded stud 331 and thus mounted within the bell chamber 303. This allows the mounting plate 317 to be secured within the bell chamber 303 without the need for specialist tools. The mounting plate 317 is adapted to accommodate two electronics components 319a, 319b in the form of printed circuit boards 319a, 319b.

Cables 40 may be provided to connect to the electronics components 319a, 319b.

Referring to Figure 8(c), there is shown a close-up of section A in Figure 8(a). There is shown a cable 40 in the form of an armoured cable 40. The armouring 43 of the cable is sandwiched between a clamp plate 44 and the mounting plate 317. The sandwiching of the armouring 43 between the clamp plate 44 and the mounting plate 37 provides earthing and cable strain relief. In the particular example of Figure 8(c), the mounting plate 315 has two threaded studs 371 that are able to be received within corresponding apertures 47 in the clamp plate 44. Nuts 49 are provided to attach the clamp plate 44 to the mounting plate 317. The use of a similar cable clamp arrangement may be provided in the other example arrangements of the present invention.

The enclosure 300 may be covered by cylindrical ducting 61 and a collar 63. The cables 40 have been cut and a hermetically sealed joint provided to rejoin them.. The cover 301 is coupled to the collar 63 using locking bolts 311 and retaining washers 313. The collar 63 and ducting 61 may not be required in all embodiments. The cover 301 could be welded directly to the bell chamber 303 if the cover 301 and bell chamber 303 are constructed of metal, and protective ducting 61 may not be required in this example.

Referring to Figure 9, there is shown an assembled view of underground electronics enclosure 300 positioned within a hole 20. Figure 9 shows that the cables 40 are connected to the electronics component 319a, 319b and extends into the hole 20. The hole 20 is shown flooded with water 50. The air pressure in the bell chamber 303 prevents water from entering the internal space of the enclosure 300, and the water level 51 remains below the electronics components 319a, 319b. This protects the electronics components 319a, 319b from water damage.

Referring to Figure 10, three different example underground electronics enclosures 300a, 300b, 300c are shown, installed in three different holes 20a, 20b, 20c.

Enclosure 300a is installed within a pole retention socket 20a with a circular cross-section. The enclosure 300a comprises a cover 301a. The diameter of the cover 301a is larger than the opening of the hole 20a, so that the cover 301a holds the enclosure 300a in place within the hole 20a. In use, the cover 301a will be substantially flush with the ground surface 23.

Enclosure 300b is installed within a square shaped pit 20b. The enclosure 300b has a surround 25. The enclosure 300b is attached to the surround 25 by a fixing arrangement 27. The fixing arrangement in this example comprises duct clamps. The enclosure 300b does not have a cover, an external ducting, or a collar.

Enclosure 300c is installed within a duct 20c with a circular cross-section. The enclosure 300c comprises a cover 301c. The diameter of the cover 301c is larger than the opening of the hole 20c so that the cover 301c holds the enclosure 300c in place within the hole 20c. In use, the cover 301c will be substantially flush with the ground surface 23.

In all of the above examples, it will be appreciated that one or more electronics components can be mounted within the bell chamber via the fixing points. The user has flexibility in selecting how the electronics components are mounted and how many electronics components may be mounted due to the fixing points. The user may use additional mounting plates and adapter plates so as to increase the number of electronics components that can be mounted in the bell chamber, or so as to provide more flexibility about how the electronics components may be mounted.

In use, the enclosure is positioned vertically within a hole with the closed top wall of the bell chamber positioned vertically upwards. The bell chamber protects the electronics components from water damage. The enclosure may be removed from the hole for maintenance. Because of the use of fixing points, the electronics components may be easily accessed, modified, and replaced. This is not provided by existing underground enclosures which require that the electronics components are potted.

In summary, there is provided an underground electronics enclosure 100 comprising a bell chamber 103 having side and top walls and defining an internal space 147 for housing an electronics component 119. The bell chamber 103 comprises at least one fixing point 121 to allow the electronics component 119 to be removably mounted in the bell chamber 103. The system comprises the enclosure 100, the electronics component 119 mounted in the bell chamber 103. A cable 40 is connected to the electronic component 119 and extends out of the bell chamber 103. The cable 40 comprises a sealed cable joint 41.

While in the above examples, specific types of fixing point such as recesses and studs have been described, it will be appreciated that the present invention is not limited to these particular examples. In general the term "fixing point" refers to a feature that provides a fixing point for mounting an electronics component. This provides a configurable system, as the end user can add and remove electronics components as they please.

In this specification, terms such as "side", "top", and "bottom" relate to the orientation of the underground electronics enclosure in normal use, i.e. positioned in a hole with the top wall of the bell chamber pointing upwards. Furthermore, the present invention minimises the size profile of the enclosure compared to existing fully waterproofed enclosures. The enclosures of the present enclosure may be positioned in existing service holes, ducts, and pole retention sockets, for example, and do not require custom dug holes for installation.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

CLAIMS1 An underground electronics enclosure comprising a bell chamber having side and top walls and defining an internal space for housing an electronics component, the bell chamber comprising at least one fixing point to allow the electronics component to be removably mounted in the bell chamber; the enclosure further comprising a cable to electrically couple the electronics component to equipment outside the enclosure; wherein the cable comprises a hermetically sealed coupler located within the enclosure, or in the vicinity of the enclosure.
2 An enclosure as claimed in claim 1, wherein the bell chamber comprises a plurality of fixing points.
3 An enclosure as claimed in claim 2, wherein the plurality of fixing points are spaced apart from one another.
4 An enclosure as claimed in any preceding claim, wherein the at least one fixing point is provided on or in the vicinity of an inner surface of the top wall of the bell chamber facing the internal space.
An enclosure as claimed in claim 4, wherein a plurality of fixing points are provided on or in the vicinity of the inner surface of the top wall of the bell chamber, and wherein the plurality of fixing points are arranged in an array comprising rows and columns.
6 An enclosure as claimed in any of claims 4 to 5, wherein the inner surface of the top wall defines at least one raised section and at least one lowered section, and wherein the at least one fixing point is provided on the at least one raised section.
7 An enclosure as claimed in claim 6, wherein the at least one raised section extends between the side walls of the bell chamber, and wherein a plurality of fixing points are provided spaced apart along the at least one raised section.
8 An enclosure as claimed in any of claims 1 to 5, wherein the bell chamber comprises a mounting structure coupled to the top wall and/or the side wall of the bell chamber, and wherein the mounting structure provides the at least one fixing point.
9 An enclosure as claimed in any preceding claim, wherein the top wall of the bell chamber is made integral with the side wall of the bell chamber.
An enclosure as claimed in any preceding claim, wherein the enclosure comprises a cover, and wherein the cover is coupled to an outer surface of the top wall of the bell chamber.
11 An enclosure as claimed in any preceding claim, wherein the enclosure comprises a lid, and wherein the lid is coupled to a bottom end of the bell chamber.
12 An enclosure as claimed in any preceding claim, wherein the bell chamber has a box shape, or wherein the bell chamber has a cylindrical shape.
13 A system comprising: an underground electronics enclosure comprising a bell chamber having side and top walls and defining an internal space for housing an electronics component, the bell chamber comprising at least one fixing point to allow the electronics component to be removably mounted in the bell chamber; and an electronics component mounted to the bell chamber via the at least one fixing point; the enclosure further comprising a cable to electrically couple the electronics component to equipment outside the enclosure; wherein the cable comprises a hermetically sealed coupler located within the enclosure, or in the vicinity of the enclosure.
14 A system as claimed in claim 13, wherein an end of the cable connected to the coupler extends out of the bell chamber.A system as claimed in claim 14, wherein the coupler couples two parts of the cable at a break in the by means of a sealed cable joint.