WO1989004590A1

WO1989004590A1 - A method and an arrangement for constructing distribution networks in telecommunication systems

Info

Publication number: WO1989004590A1
Application number: PCT/SE1988/000593
Authority: WO
Inventors: L M Ericsson Telefonaktiebolaget; Rolf Bertil HEMSTRÖM; Rolf Niklas RAMSTRÖM; Sune Erik Wahl
Original assignee: Ericsson Telefon Ab L M
Priority date: 1987-11-06
Filing date: 1988-11-03
Publication date: 1989-05-18
Also published as: SE8704354D0; SE8704354L; AU2782189A

Abstract

The invention relates to a method and to an arrangement for constructing so-called distribution cabinets in the installation of distribution networks in, for instance, a local telecommunication network, these cabinets functioning as branch points for secondary cables entering the cabinets. The inventive cabinet comprises an upstanding frame which forms, at the same time, the back plane of the cabinet and may also form a part of the side walls. In installation, the frame is buried into the ground along a part of its length. The cables concerned are drawn up to the front side of the cabinet and anchored therein. According to the invention, the front of the cabinet is divided in three sections, a bottom section, a middle section and a top section, this latter section being provided with a lid. The location of the cabinet in relation to the surface of the ground is such that the upper edge surface of the bottom front section will always protrude above ground level. The front sections are configured so that when fitting the sections into position an upper section will always lock the nearest underlying section. The top section of the frame sections is provided with locking means. The arrangement according to the invention facilitates installation work and affords protection to parts to which access is not normally required during continuous re-connecting work. Work on the branch points can also be carried out without needing to work on the ground.

Description

A METHOD AND AN ARRANGFMFNT FOR CONSTRUCTING DISTRIBUTION NFTWORKS IN TELECOMMUNICATION SYSTEMS.

The invention described herebelow will simplify and enhance the security and reliability of the installation of and service in distribution networks. As a result hereof, the distribution cabinet will obtain smaller cross-sectional dimensions than conventional cabinets of rectangular cross-section. Furthermore, the invention results in the saving of materials and also in a slimmer appearance.

- The invention, i.e. the distribution cabinet, is intended primarily to function as the branch point for the secondary cable of a local telecommunication network, and is also intended for ground installation outdoors, although the cabinet can also be adapted for installation on a wall structure. In this latter case, that part ^' of the cabinet structure which, is intended for location beneath the surface of the ground is excluded.

The principle construction of such networks is well known in the art. A multi- pair cable is branched out in the distribution cabinet into a number of cables having fewer pairs.

The physical configuration of the distribution point varies in accordance with where the¹ distribution point is located; e.g. outdoors, indoors, on a wall or a post, or in the ground. Hitherto, cabinets which are intended to stand upright in the ground have been given the configuration of a tube or a box which is buried beneath the surface of the ground and which is provided with a top cover or casing which protrudes above the ground surface, or the configuration of a cabinet provided with an openable top flap.

The invention facilitates installation procedures and is effective in protecting those parts to which access is not required during continuous re-connecting work.

The cabinet is primarily intended for ground installation. Only this embodiment of the cabinet will be described in detail in the following. Adaptation of this embodiment to other installation forms can be effected readily by one of normal skill in this art. The cabinet comprises an upstanding frame which at the same time forms the back plane of the cabinet and may also be a part of the side walls thereof,, In installation, the frame is buried beneath the surface of the ground, along a part of its length. At the same time cable pipes and underground cables are drawn to the front side of the ^'frame and anchored therein.

The lowermost section of the front sections of the cabinet is then fitted in position. The attitude or position of alignment of the cabinet in relation to the ground surface is then finally adjusted, so that the upper edge of the lowermost front section will always lie above the surface of the ground. The hole in which the cabinet is buried is then refilled, thereby to anchor the cabinet.

A moisture barrier can then be placed inside the cabinet as a filler between cables and pipes and the inner wall surfaces of the cabinet, such as to counteract the migration of ground moisture up into the cabinet and into contact with the terminal strips. The fact that the protruding edge of said front section has only a small vertical extension enables the sealing material to be placed reliably in the cabinet in an easier manner.

A suitable branch joint is then placed in the centre of the cabinet, beneath the terminal strips for the subscriber cables, which are installed_, uppermost in the frame. The branch is then connected to the terminal strips. The subscriber cables are then placed respectively on both -sides of the branch joint. The intermediate front section of the cabinet is then fitted in place to protect the branch joint.

The connection and disconnection of subscriber cables, and also those readings or measurements which need to be taken, can then be effected with the branch joint protected by the intermediate front section of the cabinet.

Work on the branch joint can be similarly carried out, without needing to work on the ground.

Finally, the uppermost front section of the cabinet, which also is the top section of said cabinet, is fitted in place. The various front sections are hooked onto the frame in a manner such as to lock the nearest underlying front piece. The uppermost front section is provided with a locking device which is manipulated with a key or knob.

The front sections simultaneously form the major part of the sides of the cabinet. The front sections have a shape such that the tangential front and side surfaces are smaller than a corresponding projected surface. This has been achieved by bevelling the vertical front corners of the cabinet or by giving said corners a curvature of large radius.

The removal of otherwise dead space in the front corners of the cabinet affords instead a cabinet of smaller volume and a pronounced slimmer appearance. A combined advantage is that of smaller material consumption together with the comparative ease with which the cabinet can be adapted to conform with the surrounding street architecture.

The arrangement of a frame which is simultaneously the back plane, and the provision of a plurality of successively covering front sections affords several advantages. The person installing the distribution cabinet has fewer parts to handle, which are lighter in weight and therewith easier to lift, with substantially lesser risk of damage to material and personal injury should a part be dropped. The various front parts or sections physically protect earlier working stages. These aspects have a particular significance with regard to future service, work and re-connection of subscriber lines in winter.

Claims

C L A I M S

1 A distribution cabinet, characterized in that the cabinet has at least three movable or detachable front sections which successively lock one another and protect successively the various anchoring, sealing, jointing and connecting points.

2 A cabinet according to claim 1, characterized in that the respective tangential front and side surfaces are at most 85% of a corresponding projected surface.