GB2313717A

GB2313717A - Enclosure for electric cables

Info

Publication number: GB2313717A
Application number: GB9710980A
Authority: GB
Inventors: Nicholas Geoffrey Turner; Anthony P Smallhorn
Original assignee: As & A Consultants Ltd As; CASS RICHARD T
Current assignee: As & A Consultants Ltd As; CASS RICHARD T
Priority date: 1996-05-29
Filing date: 1997-05-29
Publication date: 1997-12-03
Also published as: GB9710980D0; GB2313717A8; GB9611154D0

Abstract

An enclosure is provided on a building site to store temporarily a coil 14 of live electric cable 7 before it is connected to a house or a lamp-post (Figure 3). The enclosure comprises a tube 1,2 with the cable entering at the lower end, the tube being embedded in the ground. A bar 9 secure the tube in the ground. The lid 11 of the tube is locked in place. An inner member 4 seals the tube against ingress of water, and is disconnectably joined to a terminal or plug 5 on the end of the cable. The inner member 4 is lifted out to gain access to the end of the cable.

Description

ENCLOSURE MEANS FOR ELECTRIC CABLES This invention relates to enclosure means for electric cables and in particular to enclosure means suitable for enclosing a live mains supply to housing units, electric lamp standards and other installations.

It is usually necessary, when laying on supplies to housing units, electric lampstandards and other installations for a cable, which is live, to be installed adjacent to or at the intended point of use and such live supply is usually put in place in advance of completion of the installation for which the supply is intended. This poses a potentially hazardous situation. It is required that the live cable be located below the level of the ground surface to reduce the hazard.

An object of the invention is to house the live cable such as to further reduce any hazardous situation in an environment in which building and related works are taking place. A further object is to provide enclosure means which is simple and efficient to install.

According to the invention enclosure means for electric cables comprises outer tube means for upright location in the ground and having a lower entry for said cable, an inner member for location removably within the outer tube means and enclosing a space within the outer tube means below said member, supporting means situated internally of the outer tube means and below said member for supporting the free end of said cable, the cable extending from said lower entry to said supporting means and the cable being withdrawable with the inner member through the upper end of the outer tube means to obtain access to the free end of the cable.

Conveniently the outer tube means is generally cylindrical and the inner member is located in the lower part of the outer tube means in use.

Preferably the lower end of the outer tube means defines a space for locating a coil of said cable.

In one arrangement the outer tube means is formed of at least two coaxial telescopic tubes wherein the length of the outer tube means is variable.

The supporting means may comprise a hook or an eye depending from the lower side of the inner member and engageable with or otherwise connectable to an opening at the free end of the cable.

The upper end of the inner member may include a handle for grasping and raising the inner member relative to the outer tube means. Conveniently the upper end of the outer tube means includes removable cap means having locking means therefor to deter unauthorised access to the enclosure means.

The arrangement is intended to locate live electric cable and the cable is usually formed with a terminal for electrical connection to a further cable.

The outer tube means is intended for securable location in the ground by securing means which is engaged with the lower end of the outer tube means, the upper end of the outer tube means being arranged to extend above ground level.

The outer tube means may, in use, be embedded in concrete or the like in the ground, and said securing means may include a bar extending through the lower end of the outer tube means.

The inner member may be in the form an inner tube having a closed upper end, the inner member acting as a bell housing.

Alternatively the inner member is a sealing element sealed against the inner wall of the outer tube means and movable in and out of the upper end of the outer tube means. The sealing element may include a disk-like member having a seal towards its outer periphery to seal with said inner wall.

The inner tube may be releasably securable to the outer tube means towards the lower end thereof. One arrangement for achieving this is to provide a bayonet connection between the lower end of the inner tube and the lower end of the outer tube means. This may be by provision of cooperating slots formed at the lower end of the inner tube engageable with a bar extending across the lower end of the outer tube means.

When used for electrical connection to a lamppost the outer tube means may be arranged to act as a receiving member for the lamppost base.

Further features ofthe invention will appear from the following description of embodiments of the invention given by way of example only and with reference to the drawings, in which: Fig 1 is a vertical cross-section through enclosure means in accordance with one embodiment of the invention, Fig 2 is a view of the enclosure means of Fig 1 showing how access to the cable is achieved, Fig 3 is a vertical cross-section through the enclosure means of Figs 1 and 2 when used to accommodate a lamppost, Fig 4 is a perspective view of a cable end connector for use with the enclosure of Figs 1 and 2, and Fig S is a vertical cross section through a second embodiment of the invention.

Referring to the drawings there is shown enclosure means suitable for a variety of applications in which an electric cable is to be located below ground level pending connection to a housing unit, lamppost or other location at which live cables are often installed prior to the installation for which they are intended being ready for connection.

In one application housing estates are laid out with a live feeder cable extending around where the estate is to be built. Joins are then made between the feeder cable and the locations for individual dwellings. To avoid disconnection of electrical supply for the area supplied by the associated substation, the cables to the individual houses may be live during construction. This presents a potential hazard especially since building work is carried on in the vicinity of the live cable. In order to reduce the potential hazard it is required that the live cable be located below ground. Access then has to be obtained to the live cable for electrical connection to the respective houses which hitherto has involved excavating the cable fitting a stop end and leaving the termination in the ground until required.

To accommodate this situation, and referring to Figs 1-3, there is provided, below ground level 10, a housing which consists of telescopic tubes 1 and 2 which are located in an upright position, at least in part below the ground surface 10. The tubes 1 and 2 are telescopically extendable relative to one another so as to adapt to the changes in ground level which may take place, the eventual ground level usually being at a higher level, such as shown at 3 in Fig 1.

At the lower end of the tube 1 the tube is secured in the ground by a horizontal rod 9 which extends through holes towards the lower end of the tube 1. This is intended to prevent the tube 1 being removed from the ground by unauthorised persons. In addition the tube 1 may be secured in the ground in a body of concrete 8 but this is optional in the case of use of the enclosure means for dwellings, but part of the support for other items such as lampposts (see Fig 3).

The upper end of the telescopic tube 2 may be fitted with a cap 11 to prevent the ingress of material and, optionally, to prevent unauthorised access. In the latter case the lid 11 may be secured to the tube 3 by locking means requiring a key (not shown). Furthermore the lid 11 may have a marker 12 by which the enclosure may be easily identified and marked. As a further means ofidentification the tube 1 and/or the tube 2 may carry around the outer surface marking material, such as marker tape, carrying an easily identifiable colour or marking.

Electric cable 7 is led to the location of the tubes 1 and 2 along a conduit 13 and a coil 14 of cable is formed towards the base of the tube 1 to provide a suitable length of cable according to the connection to be made between the cable and the intended installation. The free end of the cable is formed with a stop end, connector, terminal block or plug 5 which is usually waterproof and is formed to enable the connection of another length of cable (not shown) to be made to lead to the intended installation. The stop end 5 is formed with an aperture 16 on the body 17.

Within the tubes 1 and 2 is releasably locatable an inner tube 4 in the form of a bell end cover having a closed end 18 at its upper end. Undemeath the closed end 18 is formed a hook 6 engageable with the aperture 16 in the stop end 5 so as to support the free end of the cable 7 closely adjacent the upper end of the inner tube 4. Altematively the cable 7 may be connected to the end 18 by an eye instead of a hook and the stop end 5 may be attached to the eye by a tie between the eye and opening 16 by which the cable can be drawn up into the bell end cover during fixing. In the position shown in Fig 1 the inner tube 4 also locates the coil 14 of cable when the tube 4 is in its operative position. The bell end cover 4 defines a dry region for the cable end, even if water should enter the tubes 1 and 2.

The upper end of the tube 4 is formed with a handle 20 whereby the inner tube 4 may be raised upwardly through the tubes 1 and 2, the cable 7 being drawn upwards with the tube 4 towards the upper end of the tubes 1 and 2. After the inner tube 4 has been released from the tubes 1 and 2 the cable end may be accessed from the lower end of the inner tube 4 to release the free end of the cable from the bell end cover.

The upper end of the tube 4 may be formed with outwardly extending rim means 21, for example of elastomeric material which engages the inner wall of the tubes 1 and 2 to provide a seal. However the seal may be omitted at the lower end of the tube 4 oppositely located slots 22 are formed having a longitudinally extending portion and a laterally extending portion engageable by the transverse rod 9 to secure the tube 4 in the lower end of the tubes 1 and 2. The inner tube 4 is released by rotation about its axis to disengage the rod 9 from the slots 22.

Fig 2 shows the tube 4 released from the tubes 1 and 2 and the cable end 5 released from the hook 6 within the inner tube 4. It will be seen that the coil 14 has been, for the most part, unwound to enable the cable to extend above the upper end of the outer tubes 1 and 2 sufficient distance for connection to the intended installation. Usually spare coils 7 will be retained at the lower end of the tube 1 in case the stop end 5 needs to be re-made.

It will be appreciated that the use of the inner tube 4 in the form of a bell end cover ensures that, even if water should enter the enclosure, it will not reach the stop end 5 since most of the inner tube 4 will remain dry. At the same time the cable 7 and stop end 5 will be easily accessible by lifting the cable up through the tubes 1 and 2. After the intended installation has been completed the cable 7 is connected to the electricity supply housing for the installation and the enclosure is no longer required except as a conduit for the cable.

However in some cases, for example when installing lampposts, the tubes 1 and 2 can form part of the base unit of the lamppost, see Fig 3.

In Fig 3 is shown the base part 24 of a lamppost which fits into the tubes 1 and 2 and is secured therein by filling the space 25 with concrete or other fixing medium, the upper end of the space being sealed at 26. In this arrangement the stop end 5 is connected to an electrical coupling element 27 from which extends a cable 28 to a lighting fixture (not shown) secured to the upper end of the lamppost 24.

In such an arrangement for a lamppost there may also be a central longitudinal inner tube 30 extending along the lower end of the lamppost 24. Access to the joint between the stop end 5 and the connector 27 may be through a side door formed in the lamppost part 24.

The tubes 1,2 may be formed of metal or plastics material as extrusions, injection mouldings or the like. Similarly the inner tube 4 may be formed in any convenient manner.

Conveniently the tubes 1 and 2 are a close sliding fit relative to one another to allow telescopic extension of one to the other and retention in their selected position.

Referring to Fig S there is shown an alternative embodiment of the invention compared with that of Figs 1-3. In this embodiment similar parts are given the same reference numbers as that of Figs 1-3.

Thus the enclosure includes a tube 1 through the lower end of which is led electrical cable 7, optionally through a conduit , a coil 14 of cable being located within the tube 1 and the cable being terminated at its free end with a stop end or plug 5 formed with an aperture for a hook 6. Alternatively the hook 6 may be in the form of an eye and the stop end 5 may have a hooked portion.

In addition to the outer tube 1 there is provided an inner telescopic tube 2, as in the preceding embodiment, but the tube 2 may be located externally of the tube 1, if required, the tubes 1 and 2 being telescopically extendable, as before, and a close fit or otherwise arranged to retain the tube 2 at the intended telescoped position in relation to tube 1.

Instead of the bell end cover arrangement of the previous embodiment the cable end 5 is carried on a disk-like sealing member 35 having around its outer periphery a peripheral seal 36 engageable sealingly with the inner wall of the tube 1. The member 35 carries the hook 6 (or eye) centrally on its lower side and has on its upper side a connector 37 by which the member 35 can be withdrawn upwards along the tube 1, the connector 37 being in the form of the lifting knob or handle or being connectable to such a knob or handle (not shown).

The number 35 is locatable at the selected depth in the tube by forming an indent 39 in the inner wall of the tube 1 or by locating a stop 40 in the form of an inwardly directed flange, or otherwise.

The seal 36 may be an expanding seal to be expanded outwards into sealing engagement with the inner wall of the tube after locating in the selected position, or otherwise sealing with the tube 1.

The tube 1 has a transverse bar 9 located through opposite openings towards the lower end of the tube 1, as before.

By the arrangement of Fig 5 the space in the tube below the sealing number 35 seals the internal space in the tube 1 below the member, providing a location for the cable coil 14 and the end stop 5.

In other respects the arrangement and operation of the Fig 5 embodiment may be similar to that of Figs 1-3

Claims

CLAIMS 1. Enclosure means for electric cable comprising outer tube means for upright location in the ground and having a lower entry for cable, an inner member for location removably within the outer tube means and enclosing a space in the outer tube means below said member supporting means situated internally of the outer tube means below said member for supporting the free end of said cable, the cable extending from said lower entry to the supporting means and the cable being withdrawable with the inner member through the upper end of the outer tube means to obtain access to the free end of the cable.
2. Enclosure means according to Claim 1 wherein the outer tube means is generally cylindrical and the inner member is located in a lower part of the outer tube means in use.
3. Enclosure means according to Claim 1 or 2 wherein the lower end of the outer tube means defines a space for locating a coil of said cable.
4. Enclosure means according to any one of the preceding claims wherein the outer tube means is formed of at least two coaxial telescopic tubes wherein the length of the outer tube means is variable.
5. Enclosure means according to any one ofthe preceding claims wherein the supporting means comprises a hook or eye member depending from the lower side of the inner member and being engageable with a corresponding eye or hook at the free end of the cable.
6. Enclosure means according to any one ofthe preceding claims wherein the upper side of the inner member includes handle means for grasping and raising the inner member relative to the outer tube means.
7. Enclosure means according to any one ofthe preceding claims wherein the upper end of the outer tube means includes removable cap means having locking means therefor.
8. Enclosure means according to any one of the preceding claims wherein the electric cable is live and is formed of a terminal intended for electrical connection to further cable.
9. Enclosure means according to any one of the preceding claims wherein the outer tube means is securable in the ground by securing means securable to the lower end of the outer tube means.
10. Enclosure means according to Claim 9 wherein the outer tube means is embedded in concrete or the like in the ground and said securing means includes a bar extending through the lower end of the outer tube means.
11. Enclosure means according to any one of the preceding claims wherein the inner member is a sealing element sealed against the inner wall of the outer tube means and movable in and out of the upper end of the outer tubes means.
12. Enclosure means according to Claim 11 wherein the inner member includes a disklike member having a seal towards its outer periphery to seal with said inner wall.
13. Enclosure means according to any one of Claims 1-10 wherein the inner member is in the form of an inner tube having a closed upper end, the inner member acting as a bell housing.
14. Enclosure means according to Claim 13 wherein the inner tube is releasably securable to the outer tube means towards the lower end thereof.
15. Enclosure means according to Claim 14 wherein the securing means for securing the outer and inner tubes together includes a bayonet connection comprising a bar associated with the outer tube means and cooperating with slots formed at the lower end of the inner tube.
16. Enclosure means according to any one ofthe preceding claims wherein the outer tube means is arranged to act as a receiving member for a lamppost base or similar unit to which the electrical cable is to be connected.
17. Enclosure means substantially as described with reference to the drawings.