GB2167609A

GB2167609A - Cable system

Info

Publication number: GB2167609A
Application number: GB08426499A
Authority: GB
Inventors: Clifford Jarvis
Original assignee: University College Cardiff Consultants Ltd; Cardiff University
Current assignee: University College Cardiff Consultants Ltd; Cardiff University
Priority date: 1984-10-19
Filing date: 1984-10-19
Publication date: 1986-05-29
Also published as: GB8426499D0

Abstract

In order to reduce the disturbance and work involved each time a branch connection is made into a cable system laid in a duct, the duct 2 is provided with an access point 3 outside each potential customer's premises and the cables 4a, 4b laid in the duct comprise, at each access point, a stumped cable for connection to the potential customer's premises. The stumped cable is so laid, preferably in the form of a loop 5, that it is readily accessible for connection. The loop may lie in the duct or in a branch outlet where one is provided. Various constructions of ducts are mentioned. The cables may be electrical or optical. <IMAGE>

Description

SPECIFICATION Cable system This invention relates to a system of laying cables for providing communication services to a multiplicity of customers' premises.

With the rapid development of communication services such as cable TV and electrical and optical transmission of information and with the prospect of wide-spread adoption of such services, it is important to provide a system of laying a system of cables which will facilitate the connecting up of the services to what is expected to be a very high proportion of business and domestic premises.

A system at present in general use is to bury a main cable duct under a roadway or pathway and to provide outside each customer's premises, as required, a manhole box which gives access to the main cable duct. A connection between the main cable and a branch cable is made in a junction box or, alternatively, a branch cable may have to be laid in the main duct back to a distribution box.

The branch cable is then laid through a branch duct into the customer's premises. This system involves sporadic disturbance of the roadway and/or pathway, provision of a manhole and a junction box and the making of a connection into the main cable or distribution box on each occasion that a customer requires a connection into the system.

In order to reduce the disturbance and work involved each time a branch connection has to be made, we provide a system of laying distribution cables in a duct provided with an access point outside each potential customer's premises, the cables laid in the duct comprising a stumped cable for connecting each potential customer's premises into the system, the stumped cable being so laid in the duct that it is readily accessible through the access point for connection to the customer's premises when required.

In order to provide for identification of and ready access to the appropriate stumped cable, that part of the main duct outside each potential customer's premises can preferably be opened up by removal of an upper cover for the duct. The appropriate stumped cable may then be identified, say by a colour coding, and then simply run to the customer's premises through a branch outlet.

Alternatively, access to the stumped cable may be improved by providing in the main duct when it is laid a stump branch outlet at each potential customer's premises, the stumped cable being laid from the main duct into the stump branch outlet.

The stump branch outlet may be run up to the potential customer's premises, the end of it being capped. In this way when a connection to the customer's premises is required, the appropriate stumped cable can readily be made accessible for connection by uncapping the branch outlet and drawing the free end of the stumped cable, from the outlet. Preferably the stumped cable is laid in the main duct, or, when one is provided, in the branch outlet in the form of a loop. When the free end of the stumped cable is withdrawn, the loop then provides an additional length of branch cable for facilitating connection into the customer's premises. Provision of such a branch outlet with a stumped cable therein makes it unnecessary to disturb the roadway or pathway, under which the main duct may lie, when a connection is to be made.

The main duct may be provided by the special kerbstones and system described in our co-pending European Patent Application No. 83307320.8.

In this case the stumped cable is initially laid in the main duct and, when a connection to a customer is required, it may be drawn through an opening in the back wall of a kerbstone adjacent the customer's premises and run to the premises through a branch duct. The opening in the kerbstone may be made by removing a knock-out portion in the rear wall, but preferably the kerbstone at that point is provided with a stump branch outlet in which a loop of the stumped cable may be laid to facilitate withdrawal of the free end of the stumped cable from the main duct and its connection to the premises.

Alternatively, the main duct may be run nearer the boundary of the potential customer's premises, say under an adjacent footpath. In this case the duct may consist of an end-to-end series of channel sections having removable covers which are fitted to close the channel sections when the cables, including stumped cables, have been laid therein. Preferably a channel adjacent the potential customer's premises is provided with a branch outlet through which the stumped cable may be passed when it is to be connected to the custom- er's premises. Conveniently, when the cables are initially laid, a loop of the stumped cable can be positioned in the branch outlet for ease of access and to facilitate withdrawal of the stumped cable from the main or branch duct.

Alternatively, the major part of the main duct may be piping, an intermediate channel section with cover being provided adjacent each potential customer's premises for the purposes described above.

The cables laid in the system may be of any type, metal conductor or optical fibre, and the system provides the additional advantage that connections of branch cables to main cables need not be made in the confined space and under the adverse conditions of a manhole.

Embodiments of the invention are now described by way of example, with reference to the accompanying drawings in which: Figure 1 is a plan view of a system laid under a footpath adjacent potential and existing customer's premises.

Figure 2 is a part sectional view illustrating two alternative types of main duct which may be used.

Figure 3 is a part sectional view illustrating a system of main and branch ducting suitable for buildings adjoining a pathway.

Figure 4 is a diagram of a neighbourhood system suitable for terraced and detached houses.

In Figure 1 there is laid under pathway 1 a main cable duct 2 which is provided with branch outlets 3 at points suitable for connection to potential customer's premises. The main cable duct 2 contains cables 4a and 4b. Cables 4a are connected into customer's premises. Cables 4b await connection and the end portion of these cables is laid in the form of a loop 5. In the system illustrated, the end of the loop 4 lies inside the branch outlet from which the stumped end 6, which in this case lies in the main cable duct, can readily be withdrawn through the branch outlet.

Figure 2 illustrates use of two alternative types of ducts. One is of a type usable in the system illustrated in Figure 1 and comprises sections 6 which provide part of the main duct 2 and the branch outlets 3. Intermediate of branch sections 6 are plain sections 7. Both types of sections may be closed at the top by covers, but sections 7 may take the form of pipes. The sections may be of concrete, earthenware or plastic.

The other type of duct illustrated in Figure 2 is provided in the kerbstones. In this case the kerbstone consists of a lower channel section 8 closed by an upper portion 9. At the rear of the channel section 8 is an access point 10. From this a branch duct may run to the customer's premises. The branch duct may conveniently be a plastic pipe. In general kerb ducts of this type may be as described in our co-pending application referred to above.

Figure 3 illustrates in more detail possible features of the system shown in Figure 1. In this case the branch duct is a pipe 11, suitably of plastic, which is run under pathway 1 from the rear wall of main duct section 2 up to an exterior wall 12 of the potential customer's premises. A loop of stumped branch cable lies in the branch duct. The end of the branch duct is provided at pavement level or higher with a cap 13 which can be removed for withdrawal of the stump end of the branch cable when connection to a customer is desired.

Figure 4 illustrates a general system of distribution of cables from distribution boxes 14 located at street intersections 15. To serve potential customers in terraced houses 16, stumped branch cables are provided in branch ducts 11 which run up to an exterior wall of the customer's houses as illustrated in more detail in Figure 3.

In the case of detached houses 17, the stumped branch cable is again laid in branch ducts 11 which run up to an exterior wall of a potential customer's premises. The whole of this system can be laid down in one operation. At that time actual customers can be connected up immediately. Potential customers can be connected up later without any further disturbance of the pathway.

Claims

1. A system of laying distribution cables in which cables are laid in a duct provided with an access point outside each potential customer's premises, the cables laid in the duct including, at each access point, a stumped cable for connecting the potential customer's premises into the system, each stumped cable being so laid that it is readily accessible through the access point for connection to the customer's premises when required.

2. A system as claimed in claim 1 in which that part of the duct provided with an access point has a removable cover.

3. A system as claimed in claim 1 or claim 2 in which the access point is provided by a stump branch outlet from the duct.

4. A system as claimed in claim 1 or claim 2 in which the access point is provided by a branch from the duct, the branch running up to the potential customer's premises.

5. A system as claimed in any preceding claim in which the duct is provided in kerbstones adjacent the potential customer's premises.

6. A system as claimed in claim 5 in which the access point is a knock-portion in the rear wall of a kerbstone.

7. A system as claimed in claim 5 in which the access point is provided by a stump branch outlet in the rear wall of a kerbstone.

8. A system as claimed in any preceding claim in which the stumped cable is laid in the form of a loop, either in the duct or in a branch or branch outlet where one is provided, the loop when drawn out providing an additional length of cable for connection to the potential customer's premises.