GB2299351A - Crossing equipment - Google Patents

Abstract

Crossing equipment suitable for use when cabling across a road or railway comprises columns mounted on bases, each column being stabilised by at least one strut extending from an upper point on the column to the ground, and each column also being capable of supporting a range of different fittings at its upper end.

Description

CROSSING EOUIPMENT Field of the Invention The present invention relates to crossing equipment suitable for, but not restricted to cabling across roads, railways and the like.

Such crossing equipment will be defined as crossing equipment "of the kind in question".

Background to the Invention Overhead cables have become a feature of the landscape these days. There is now an even greater tendency for these cables to proliferate with the advent of the so-called "information superhighway" or "internet" whereby data and/or speech signal cables have been installed alongside power lines for example. This can involve lightweight fibre optic cables being strung along existing electricity pylons.

Conventionally, when a line is being cabled at a point where it crosses a road or railway, it is necessary to protect the road or railway by means of a net suspended beneath the course of the power line. Where the road is only narrow, horizontal poles are simply located on each side of the road and the net is omitted, any trailing cable being carried by the poles over the road.

The poles and/or nets are mounted on scaffolding structures erected especially for the job.

The erection and dismantling of scaffolding is a skilled job, and the use of scaffolding is therefore relatively costly. Therefore, in order to ensure that the scaffolding is in position when the cabling is to be carried out, it is often necessary to have it erected some time in advance of when it is needed, according to the availability of the skilled scaffolders. For the same reason, the scaffolding may remain in position for some time after the cabling job has been completed. This can further increase the cost.

One solution to this problem is described in PCT/GB94/00115, which is the closest prior art known to the applicant. This describes easily erected scaffolding columns, pivotally mounted on transportable bases. At least two of these columns are erected side by side with a connection therebetween.

This type of arrangement is shown in Figure 1. Each column is relatively heavy and certainly cannot be manoeuvred single-handedly. Furthermore every column must be guyed to steady it against toppling as well as being used in tandem.

However, when it comes to putting up lightweight cables such as fibre optic, 33 Kv, 66 Kv or 132 Kv electric cables even this type of system is unnecessarily complex and unwieldy. Furthermore it does not provide in itself for a pulley or sheave through which the cable can be drawn.

It is the object of the present invention to overcome these shortcomings and provide lightweight, stable crossing equipment which can be easily erected single-handedly or by a small team and which makes provision for drawing cables.

Summarv of the Invention According to the present invention, in its broadest sense, there is provided crossing equipment of the kind in question characterised by the following combination of features: (a) abase; (b) a column supported on said base; (c) an adaptor connectable to the top of the column; (d) one or more struts connected at a first end to the uppermost in use part of the column, the strut extending to the ground such that the second end engages the ground at a point distant from the base; the crossing equipment being so adapted that, in use, it is freestanding without the need for guys, ropes or other supports.

Preferably the base comprises (a) a heavy mass mounted on a base plate and (b) a plurality of outriggers, the outriggers extending radially from the base to increase the effective area of the base plate and thus steady said column against any tendency to topple when under load.

Preferably the outriggers each incorporate adjustable feet located at or towards the end of the outrigger furthest from the base such that, in use, the adjustment can accommodate undulations in the terrain and thus maintain the base in a stable configuration.

In a particularly preferred embodiment the outriggers are a sliding fit within the base.

Preferably the struts are pivotally connected to the column.

Preferably the struts incorporate or fit into ground engaging anchor plates, spreading the load transmitted through the strut over a larger area.

In a particularly preferred embodiment the column comprises a series of interlocking sections.

Preferably the column has a hexagonal cross-section.

Brief Description of the Drawings Preferred embodiments of the present invention will now be more particularly described by way of example only, with reference to the accompanying drawings where: Figure 1 shows a series of columns as described in PCT/GB94/00115; Figure 2 shows top, middle and bottom sections of a column according to the invention; Figure 3 shows side and front views of a hinged stretcher; Figure 4 shows a side elevation of a base; Figure 5 shows outriggers of two lengths with adjustable feet; Figure 6 shows a variety of heads adapted to fit into the top of a column; Figure 7 shows side and plan elevations of an alternative base minus base plate; Figure 8 shows a cross-section of a column and the A Section from which it is constructed; Figures 9 and 10 show side and plan elevations of two columns joined together;; Figure 11 shows how stretchers may be used to join columns.

Description of the Preferred Embodiments The present embodiments represent currently the best ways known to the applicant of putting the invention into practice. But they are not the only ways in which this could be achieved. They are illustrated, and they will now be described, by way of example only.

Referring to Figure 1 this shows top, intermediate and bottom sections 10, 11, 12 of a column according to a first aspect of the invention. These sections are constructed from hollow, tubular material and are generally hexagonal in cross-section as shown in Figure 8. Each end of the various sections are specifically adapted for a purpose. For example, the lowermost in use portion 13 of the bottom section 12 is adapted to be a sliding fit into a base 22 (see below). The uppermost in use portion of this bottom section 14 is designed to accept an intermediate section 11 and a joining pin 15 is provided to lock these two components in position. The joining pin prevents the two components separating and also prevents rotation of one component relative to the other.

The intermediate section is therefore adapted at one end to form a sliding fit with the bottom section with corresponding provision for a joining pin.

The intermediate section has what is in effect a "male" and a "female" end such that, within reason, a number of intermediate sections of different lengths can be added one on top of another to give a column of literally any desired height. Likewise the top section can slide into an intermediate section or directly into a bottom section. The top section 10 incorporates two important features. Firstly there are stretcher lugs 20, a stretcher being a strut which extends from near the top of the column to the ground to provide lateral support against toppling forces. Secondly, the uppermost in use end of the column is adapted to accept a top fitting 21 such as a sheave as shown in Figure 1 or any of the variations shown in Figure 6. The type of fitting is chosen to suit the cabling work being undertaken. A swivel joint head 33 can be interposed between the end of the column 19 and the fitting 21 such that the fitting can rotate.

To erect the column the required sections are joined together whilst they lie on the ground. The bottom section is then inserted into a base 22 and these two pieces bolted together by means of a locking ring 24 attached to the column and corresponding locking ring studs 25 attached to the base.

In this example the base 22 is a generally conical shaped weight on a base plate 23. Outriggers 26, 27 are then usually inserted into the base 22 such that they extend radially outwards therefrom. These outriggers add substantially to the stability of the whole assembly without adding greatly to the weight.

They effectively give the base a notional diameter of twice the length of the longest outrigger.

The column is then erected in much the same way that a flag pole is put up i.e by raising it from the end furthest from the base. Additional outriggers can then be inserted into the base as necessary.

If additional sideways support is required then stretchers 28 can be secured between the stretcher lugs 20 and ground anchor plates 29 (not shown).

Where the conditions permit both the ground anchor plates and the base can be secured by spikes driven into the ground.

Figure 7 illustrates an alternative type of base which allows the column and base to pivot on a base plate (not shown). A socket 40 carrying a locking ring 41 is attached to a first plate 40. A column bottom section 13 can be inserted into the socket 40 and secured by bolting together the two locking rings.

Studs for this purpose may be provided on one or other of the locking rings.

The plate 42 has three lugs 43, 44 adapted to co-operate with three similar fixings on a base plate 45 (not shown). By bolting lugs 44 onto the base plate but leaving lug 43 unattached, this provides a pivotal arrangement. It is now possible to secure the base plate 45 to the ground with ground anchors of some type, assemble the various components of the column at ground level with the socket 40 substantially parallel with the ground. Once all items are in place the column is simply pivoted about lugs 44 and once upright lug 43 is secured onto its counterpart in the base 45. This simplifies erection considerably and makes it virtually a one man operation.

Any of these bases can incorporate outriggers and these provide a useful method of adding weight to the base to give increased stability. Weights can be laid on or across the outriggers directly or on a board placed across two outriggers, the weights being placed on the board.

It will thus be appreciated that the whole structure has been sub-divided into sections that are easily loaded into an all-terrain vehicle or an estate car as well as being manoeuvrable by one person.

Thus a single pole type system has been developed with multi-facet adaptable interchangeable heads with various working functions i.e single sheaves, multi-sheave, swivel connection for various job types. Single poles can also be made into a string of poles in line or along a non-linear route as required and as illustrated in figures 9, 10 and 11. In these illustrations each single pole has three stretchers attached to an upright via a pin connection using a concrete with steel adaptor fixed inside a block of various weights, typically 100 Kg to 1170 Kg. For soft ground loading steel adaptor plates with steel spikes would be used for outriggers and stretchers. Any type of netting system required would be attached to the ground anchors and not to the uprights and/or cross bars.

These systems can be further stabilised by providing adjustable feet 40 at the outward end of the outriggers. These feet can be used to accommodate any undulations in the terrain and thus to reduce any tendency for the column to wobble about its vertical axis.

The crossing equipment can be constructed from any strong, durable material such as aluminium or steel, with or without a protective coating such as anodising or galvanising. This material will be selected by a materials specialist depending upon the required conditions of use.

It will be appreciated that columns of different heights can be erected in line on the approach to a crossing so as to support a cable on its way from ground level up to the crossing point itself.

Claims (11)

1. Crossing equipment of the kind in question characterised by the following combination of features: a) abase; b) a column supported on said base; c) an adaptor connectable to the top of the column; d) one or more stabilising struts connected at a first end to the uppermost in use part of the column, the strut extending to the ground such that the second end engages the ground at a point distant from the base; the crossing equipment being so adapted that, in use, it is freestanding without the need for guys, ropes or other supports.

2. Crossing equipment as claimed in Claim 1 wherein the base comprises (a) a heavy mass mounted on a base plate and (b) a plurality of outriggers, the outriggers extending radially from the base to increase the effective area of the base plate and thus steady said column against any tendency to topple when under load.

3. Crossing equipment as claimed in Claim 2 wherein one or more outriggers each incorporate adjustable feet located at or towards the end of the outrigger furthest from the base such that, in use, the adjustment can accommodate undulations in the terrain and thus maintain the base in a stable configuration.

4. Crossing equipment as claimed in Claim 2 or Claim 3 wherein the outriggers are a sliding fit within the base.

5. Crossing equipment as claimed in any preceding claim wherein the struts are pivotally connected to the column.

6. Crossing equipment as claimed in any preceding claim wherein the struts incorporate or fit into ground engaging anchor plates, thus spreading the load transmitted through the strut over a larger area.

7. Crossing equipment as claimed in any preceding claim wherein the column comprises a series of interlocking sections.

8. Crossing equipment as claimed in Claim 7 wherein the interlocking action is achieved by means of detachable inserts so sized and shaped that they are a sliding fit within each section.

9. Crossing equipment as claimed in any preceding claim wherein the column has a hollow hexagonal cross-section.

10. Crossing equipment substantially as herein described with reference to and as illustrated in any combination of Figures 2 to

11.