GB2221935A

GB2221935A - Demountable top for telephone pole

Info

Publication number: GB2221935A
Application number: GB8918104A
Authority: GB
Inventors: John Michael Haley; David Ian Monro
Original assignee: British Telecommunications PLC
Current assignee: British Telecommunications PLC
Priority date: 1988-08-18
Filing date: 1989-08-08
Publication date: 1990-02-21
Anticipated expiration: 2009-08-08
Also published as: GB2221935B; GB8918104D0; GB8819650D0

Abstract

A demountable pole top comprises a cap 1 adapted to fit over the exposed end of a support pole 2. An annular support 5 is provided to enable connection of overhead drop wires 7 (e.g. telephone conductors) without direct attachment to the support pole. If replacement of the pole 2 becomes necessary the assembly may be lifted by (e.g.) a crane using an eye 4 or a through-bore in struts 6, whilst the pole is replaced thus avoiding service interruptions. Housing 10 contains connectors for electrical or optical fibres. <IMAGE>

Description

OVERHEAD LINE MOUNTING COMPRISING A DEMOUNTABLE POLE TOP ASSEMBLY The present invention relates to overhead line mounting and more particularly but not exclusively to overhead line mountings for telecommunications drop wires.

For the avoidance of doubt the term "drop wires" as used herein is not limited to electrically conducting wires and specifically includes interconnections comprising optical fibres.

Most domestic telephone installations in the United Kingdom for example are connected by use of overhead drop wires supported at one end close to the top of a wooden pole and at the opposed end by the building to which telephone service is to be provided. Many poles are affected by rot, often at the top of the pole due to ingress of rainwater or below or just above ground level.

Other poles are affected by collision damage for example.

In order to replace damaged or decayed poles it is usually necessary to disconnect all of the components at the top of the pole so that the old pole can be removed and, subsequent to fitting a new pole, to replace such components. It will be appreciated that such action results in a loss of service to up to twenty or more customers for a possibly unacceptable period of time.

One alternative to the above method of operation is to position a new pole in the vicinity of the old pole and reprovision cabling and drop wires between the pole and customers premises. Although this limits the service disconnection period, it is expensive in both manpower and component costs.

It is one object of the present invention to provide an overhead line mounting which substantially avoids loss of customer service during pole replacement operations.

According to the present invention there is provided a demountable pole top assembly for use in overhead line mounting, characterised in that the assembly comprises cap means (1) having at one end means (4,12) to co-operate with a lifting mechanism and, at the opposed end, an opening leading to a chamber adapted to receive an exposed end of a support pole (2), the assembly further comprising straining means (5) to which at least one overhead connection (7) may be mechanically coupled (8) whereby in use overhead connections may be supported without direct mechanical coupling to a support pole (2).

The assembly may comprise a housing for electrical terminations and/or for housing passive or active electro-optical and/or opto-electrical converters.

The straining means preferably comprises an annular member attached to and spaced apart from the cap means.

A demountable pole top assembly in accordance with the invention will now be described by way of example only with reference to the accompanying drawings of which: - Figure 1 is a schematic perspective view of a first pole top assembly; - Figure 2 is a side view of a second pole top assembly; - Figure 3 is a side view of the assembly of Figure 2 from a different angle; and - Figure 4 is a plan view of the assembly of Figure 2.

Referring to Figure 1, the pole top comprises a cylindrical sleeve 1 of metal or plastics material formed to fit over the exposed end of a supporting pole 2. The closed end 3 of the sleeve 1 incorporates an eye 4 which facilitates lowering of the top over the pole 2 on initial installation using a crane and subsequently allows the top to be supported during pole replacement operations.

An annular support ring 5 constituting straining means of the present invention surrounds the sleeve 1 and is spaced apart from the sleeve by members 6 welded to or integrally formed with the sleeve. On installation drop wires 7 (only one of which is shown) which are connected at the opposed end to (e.g.) the facade of a building are linked to the support ring 5 by strainer wires 8 which are looped around the ring. The drop wire 7 is then electrically linked to a multicore cable 9 in a terminal box 10 attached to the sleeve 1. The multicore cable 9 is a normal cable running the length of the pole 2 and thence by way of a distribution cabinet to a telephone exchange.

In addition to providing support to the drop wires 7, the sleeve provides some environmental protection for the pole 2 by inhibiting water ingress and incorporates a drip flange 11 thereby directing accumulating rainwater away from the pole surface.

Referring now to Figures 2, 3 and 4, in an alternative embodiment the demountable top is adapted for fitting to a shaped support pole 2(. In this case, the ring 5 is clamped to the sleeve 1 using a threaded rod 6' and bolt arrangement, the rod 6' passing through an integral tube 12. As with the embodiment of Figure 1, a drip flange 11' serves to direct rainwater away from the surface of the pole 2'.

As may be seen from Figure 4, the terminal box 10 is attached to the sleeve 1' by means of a shaped bracket 14 which includes locating guides 15 to hold the multicore cable 9.

The sleeve 1' also includes an aperture 16 through which a screw threaded bolt may be inserted to facilitate locking of the pole cap in a desired position. On installation of the cap, the tube 12 is used as an alternative to the eye 4 of Figure 1 to effect lifting by means of a crane or similar.

It is here noted that since, in normal usage, drop wires are substantially evenly distributed around the distribution point, the net stress on the ring 5 is substantially balanced reducing the need for high strength material usage.

It is further noted that the assembly is readily converted for use with optical fibre drop wires for example since the terminal box 10 may have passive or active opto-electrical and/or electro-optical components.

The system may also be used for interconnecting an optical signal distribution cable from the transmission network to electrical signal overhead connections.

Alternatively, the housing 10 may enclose an optical fibre connection tray such as disclosed in our co-pending United Kingdom Patent Application No 8805017 whereby optical drop wires may be coupled to optical fibre distribution cable without introducing excessive curvature to the fibres.

Claims

1. A demountable pole top assembly for use in overhead line mounting, characterised in that the assembly comprises cap means (1) having at one end means (4,12) to co-operate with a lifting mechanism and, at the opposed end, an opening leading to a chamber adapted to receive an exposed end of a support pole (2), the assembly further comprising straining means (5) to which at least one overhead connection (7) may be mechanically coupled (8) whereby in use overhead connections may be supported without direct mechanical coupling to a support pole (2).

2. A demountable pole top assembly as claimed in Claim 1 further characterised in that a terminal housing (10) is attached to the cap means (1), the terminal housing enclosing terminals for effecting electrical interconnection between the at least one overhead connection (7) and a multicore distribution cable (9).

3. A demountable pole top assembly as claimed in Claim 1 further characterised in that a terminal housing (10) is attached to the cap means (1) the terminal housing enclosing opto-electric and/or electro-optic conversion means whereby interconnection between an optical signal transmission system and an electrical signal transmission system may be effected.

4. A demountable pole top assembly as claimed in Claim 1 further characterised in that the cap means (1) carries an optical fibre splice support whereby interconnection between optical overhead connections and multicore optical cables may be effected.

5. A demountable pole top assembly as claimed in any one of Claims 1 to 4 further characterised in that the straining means comprises an annular member (5) attached to and spaced apart from the cap means (1).

6. A demountable pole top assembly as claimed in any preceding claim further characterised in that the cap means (1) includes an aperture (16) to permit attachment of the assembly to a pole (2) using a screw threaded member.

7. A demountable pole top assembly as claimed in any preceding claim further characterised in that a flange member (11) is provided towards the opposed end arranged to direct water away from the surface of the pole (2).

8. A demountable pole top assembly substantially as hereinbefore described with reference to Figure 1 or Figures 2, 3 and 4 of the accompanying drawings.