GB2301339A

GB2301339A - Timber drum for cable

Info

Publication number: GB2301339A
Application number: GB9608405A
Authority: GB
Inventors: Paul Graham Tickle; Stewart Berkley Turner; James Thomas Logan
Original assignee: PENTRE GROUP Ltd
Current assignee: PENTRE GROUP Ltd
Priority date: 1995-04-27
Filing date: 1996-04-23
Publication date: 1996-12-04
Anticipated expiration: 2016-04-23
Also published as: GB2301339B; GB9608405D0; GB9508570D0

Abstract

In a timber drum comprising two timber flanges and a barrel made up of timber lagging, at least one barrel lagging support member comprises a single ply timber annulus formed from a plurality of planks 23. Each plank has an end 3 cut for abutting against a side 5 of an adjacent plank. The planks are secured together by gang nailing across the line contact therebetween. The planks may be preshaped or when all planks have been secured together the resulting annulus can be trimmed to give the desired peripheral shape.

Description

TITLE: Improvements in and relating to timber drums for cable DESCRIPTION The present invention concerns improvements in and relating to timber drums for cable and the like.

A traditional timber drum comprises two timber flanges (usually made from a plurality of planks) and a barrel made up of timber lagging supported on barrel support segments which are secured to the flanges. The support segments and flanges are drilled through to take longitudinal tie bars extending between the flanges determining the axial spacing thereof, whilst at least some of the segments are recessed to receive additional longitudinal stringers made of timber and set into the recesses cut in the barrel support segments. These longitudinal supports serve to reinforce the barrel to prevent it collapsing inwardly under cable loading.

Deflection of the barrel under load is a problem which has been previously addressed by producing a centre support comprising a two-ply timber annulus made from a plurality of timber segments which have each of their ends cut to mate at the correct angle with an adjoining segment and wherein the segments making up one-ply are nailed to the segments making up the other ply to form the annulus. The annulus will have a substantially circular periphery whilst the inner configuration will usually comprise a plurality of flats with a segment of one-ply overlapping the joint between two segments of the other ply. The longitudinal securing bolts pass through holes in the annulus to allow it to be positioned centrally within the barrel and thereby support the lagging intermediate the flanges.The use of a centre support is advantageous but the afore-described construction is time-consuming to make, uses a large quantity of timber because of the two-ply construction, and is not particularly strong.

It is an aim of the present invention to provide an improved barrel lagging support construction.

Accordingly, one aspect of the present invention provides a barrel lagging support member comprising a single ply timber annulus having a substantially circular periphery and formed from a plurality of timber planks each of which has an end cut for abutting against a side abutment of an adjacent plank and wherein the planks are secured to one another by gang nailing.

Advantageously, the outer circular configuration is machined after securing together of the aforesaid planks to form a basic annulus. Conveniently said side abutment is part of a straight side of the plank and in the preferred embodiment, the remainder of said sides defines the internal aperturing of the annulus as a series of straight sides equal in number to the number of planks employed. The angle of the cut end reflects the number of planks forming the annulus. Thus, where four planks are employed the end will be cut at right angles to said one side. We envisage annuli with four, five and six planks. The angle of the cut end of each plank is equal to 3600 divided by the number of planks forming the annulus.

Another aspect of the invention comprises a method of making a barrel lagging support comprising producing a plurality of planks having an end cut at a desired angle to a side abutment surface, positioning an end of one plank adjacent said side abutment surface of another plank (preferably by assembling the planks around an inner template), and gang nailing across the line contact therebetween to one side and the other side.

The method preferably further comprises trimming the assembled planks to form the desired outer circumferential shape.

A yet further aspect of the invention provides a timber cable drum comprising timber end flanges, timber barrel lagging and at least one barrel lagging support member as described herein above for supporting the barrel lagging.

The present invention will now be described further, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is an orthographic view of one embodiment of barrel lagging support member in accordance with the invention, Figure 2 is an end view showing the first step in the manufacture of a barrel lagging support member in accordance with the invention, Figure 3 is an end view showing a second step in the manufacture of a barrel support member in accordance with the present invention, Figure 4 is a perspective view of one embodiment of timber cable drum incorporating one barrel lagging support member, and Figures 5 and 6 are end views of alternative embodiments of barrel lagging support member.

Referring firstly to Figure 1 there is illustrated a first embodiment of barrel lagging support member made up of four pieces of timber 1 with an end 3 of each abutting a side 5 of an adjacent piece 1 and joined by gang plates 7 positioned to opposite sides of the annulus and straddling the line joint between the adjacent pieces. The advantage of this construction is that when working with planks of timber, usually with at least one straight side and most usually with two parallel sides, it only requires one end (eg. 3) to be cut at a precise angle (a) for joining with the adjacent piece of timber. More advantageously still, when the basic annulus has been assembled it is then machined to form the desired outer diameter. Of course, pre-cut pieces 1, ie. with desired curvature, could be utilised.

Referring to Figures 2 and 3, here we illustrate how the barrel lagging of Figure 1 is constructed according to one method. As shown in Figure 2 a square template 21 is employed and planks 23 of the approximate length are positioned around the sides of the template so that the cut end 3 of one plank abuts against the side 5 of an adjacent plank whereupon the joint is secured using gang nailing - see gang nailing plate 7 in Figure 3. For the purposes of illustration we show all four planks in position before gang nailing but in practice two planks may be positioned then gang nailed and then additional planks added to make up the annulus as illustrated in Figure 3 which is then turned over and gang nailed on the other side prior to being positioned in a machine (such as a band saw on a suitable template and rotated to cut the outer diameter) as shown in dotted outline at x.A construction of this nature is both strong, easy to produce and economical having regard to material utilisation.

Referring to Figure 4, here we illustrate a timber cable drum comprising two timber flanges 51 typically made up of two plies of planks disposed at 900 to one another and with one-ply nailed to the other.

The drum also comprises barrel lagging support segments 53 forming a circular outer surface for the barrel lagging comprising planks 55 only some of which are illustrated in order to show the inner construction of the barrel. Longitudinal tie rods 57 of steel bar extend between the flanges to tie them together axially.

In order to support the barrel lagging intermediate the flanges a barrel lagging support member 59 is provided and constructed as described herein. In the illustrated embodiment only one barrel lagging support 59 is provided but there may be more than one so that the thickness of the lagging can be decreased or the length of the barrel increased. The barrel support segments 53 may be replaced by the afore-described barrel lagging support member and conveniently secured to the flanges.

Figures 5 and 6 show alternative configurations of barrel lagging support member comprising five and six pieces 1 respectively and with the ends 3 cut at the appropriate angle a. Conveniently, the members are built up around an appropriate template as previously described and the outer circumference machined after gang nailing.

The reference to "single ply" in the present context is to distinguish over the prior art. The timber pieces employed will usually comprise solid timber pieces, but the expression is not to be taken as excluding pieces which are other than solid timber, eg.

multi-ply construction or otherwise where such can be gang nailed.

Claims

1. A barrel lagging support member comprising a single ply timber annulus having a substantially circular periphery and formed from a plurality of timber planks each of which has an end cut for abutting against a side abutment of an adjacent plank and wherein the planks are secured to one another by gang nailing.

2. A barrel lagging support member as claimed in claim 1, in which the side abutment is part of a straight side of the plank.

3. A barrel lagging support member as claimed in claim 2, in which the reminder of each of said straight sides defines an internal aperture of said annulus, there being a number of straight sides to said annulus equal in number to the number of planks employed.

4. A barrel lagging support as claimed in claim 1, 2 or 3, in which the angle of the cut end of each plank is equal to 3600 divided by the number of planks forming the annulus.

5. A barrel lagging support member as claimed in any one of claims 1, 2 or 3 comprising four planks and in which the end of each plank is cut at 900 to said one side.

6. A barrel lagging support as claimed in any one of claims 1 to 5, in which the planks are pre-cut with a desired curvature extending between said one side and said cut end.

7. A barrel lagging support member constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings of Figures 1, 5 or 6.

8. A method of making a barrel lagging support comprising a single ply timber annulus, the method comprising the steps of producing a plurality of planks having an end cut at a desired angle to a side abutment surface, positioning the cut end of one plank adjacent a side abutment surface of another plank and gang nailing across the line contact therebetween to one side and the other side, repeating the positioning and nailing step for each cut end corresponding to the number of planks forming the timber annulus.

9. A method as claimed in claim 8 and further comprising trimming the assembled planks to form the desired outer circumferential shape.

10. A method as claimed in claim 8, in which the planks are preferred with a desired curvature extending between said one side and said cut.

11. A method as claimed in claim 8, 9 or 10 comprising cutting the end of each plank and an angle equal to 3600 divided by the number of planks forming the annulus.

12. A method as claimed in any one of claims 8 to 11 in which the plurality of planks are assembled around an inner template.

13. A method as claimed in any one of claims 8 to 12, in which the step of gang nailing is performed on one side each time a cut end is positioned against a side abutment and all the gang nailing is completed to one side before the annulus is gang nailed from the other side.

14. A method of making a barrel lagging support substantially as hereinbefore described with reference to the accompanying drawings of Figures 1, 2 and 3.

15. A timber cable drum comprising timber end flanges, timber barrel lagging and at least one barrel lagging support member as claimed in any one of claims 1 to 6.

16. A timber cable drum constructed and arranged substantially as hereinbefore described with reference to and as illustrated in Figure 4 of the accompanying drawings.