GB1571793A

GB1571793A - Columnar structures

Info

Publication number: GB1571793A
Application number: GB4791575A
Authority: GB
Original assignee: BRC HIGHTOWER Ltd
Current assignee: BRC HIGHTOWER Ltd
Priority date: 1976-11-16
Filing date: 1976-11-16
Publication date: 1980-07-16

Description

(54) COLUMNAR STRUCTURES (71) We, BRC-HIGHTOWE.R LIM ITED, a British company of 96-98 Marsham Street, London SW1P 4LY, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a columnar structure for carrying a member at a height above the ground.

According to the present invention, there is provided a columnar structure adapted for carrying a member at the upper end of the structure above the ground, comprising a plurality of elongate rigid tubular members (joined end to end) each tubular member being of a height greater than width in any transverse cross-sectional direction and being formed from sheet or strip material of reticular form.

More particularly, in preferred embodiments, this invention provides, inter alus a columnar structure as aforesaid which is a street lighting column (lamp post), a column used to carry a lighting array as in outdoor floodlighting arrangements on permanent or temporary sites, a column used to carry a radio communication aerial, a navigational beacon1 wind generators and metereological equipment in general or a column used in the support of overhead power transmission lines.

Two or more columnar structures may be used to support a single head load.

The material from which the columnar structure is constructed will, owing to its reticular nature, have a high strength to weight ratio and greatly reduced effective wind resistance as compared with conventional solid structures such as street lighting columns.

Moreover, a columnar structure embodying this invention is visually less obstructive than a corresponding solid column structure. A columnar structure embodying this invention is of particular value in being frangible so as to undergo a form of crumpling when struck by a moving mass. This frangibility is a desirable property of olumns installed on airfields or roads where damage caused by im paot is a particular hazard. The frangibility of the columnar structures is a desirable feature insofar as street lighting columns are concerned. A vehicle such as a car colliding with a conventional column at a speed of 25 k.p.h.

would suffer as much immediate damage as it would when in collision with, for example, a brick wall. The column may be uprooted and fall on the impacting vehicle or any other vehicles or personnel in the vicinty. With a columnar structure embodying this invention, it is much less likely that such danger will result and in fact the manner of collapse of the column may be such that a functional member carried thereon may be able to continue to operate even after impact. However, the ability of a columnar structure to fail safely when subject to abnormal shock is of particular value where aircraft are cons cerned. The wing tip of a landing aircraft striking a non-frangible structure could result in disaster from two major causes. Firstly, the aircraft may become unstable and uncontrollable.Secondly, parts of the structure hit can be projected at high velocity with obvious consequences. Owing to the structures being inherently frangible, parts will generally not be projected therefrom and if any parts should be so projected, they will be of minimal mass.

In general, columnar structures embodying this invention will have heights of up to about 18 metres. They will be of low mass because of their construction and will usually be capable of supporting head loads of up to 300 pounds when subject to wind velocities of up to 50 metres per second. Put differently, a 10 metre column may be capable od supporting a head load presenting a surface area of 2 square metres in a wind velocity of 48 metres per second. Moreover, as mentioned hereinabove, a columnar structure embodying this invention has a high strength to weight ratio. Thus a 10 metre column as aforesaid may weigh less than 40 kilograms.In contrust, 10 metre columns made from steel sheet or steel tube, these being the materials conventionally used to make street lighting columns, weigh on average 100 kilograms and 115 kilograms respectively.

It is generally preferred that the individual tubular member making up the columnar structure be not more than 6' or 2 metres high and that, when a columnar structure of greater height is required, it be formed from a plurality of such columns connected together eadwise for example as will be described hereinafter with reference to the accompanying drawings.

Columnar structures embodying this invention will generally be made of metal, for example steel or aluminium. Alternatively, for example, the column(s) may be formed of synthetic resin reinforced, for example, with glass fibres or carbon fibres. The term "reti- cular" used herein, denotes a structure in the form of a mesh, or mesh-like. Thus, the structures may be made from steel sheet perforated so as to be mesh-like or from expanded steel sheet (steel sheet with slits which allow it to be expanded to form a mesh structure). However, it is preferred that the columnar structure be made from open mesh sheet manufactured as such from metal wire or rods.The preferred material is in fact open mesh manufactured by laying a series of high tensile steel wires or rods at right angles to each other to form a matrix, the wires being welded together at each intersection. The matrix or mesh size can be varied as required. To form the individual members, sections of required length may simply be rolled until their ends meet and a weld formed at the joint line, for example using a welding strip. It will be most convenient to form the members of circular form since only a single longitudinal weld is then needed. However, it is possible to form the members of other cross-section, for example triangular or square.The members may be of the same cross-section or successive ones thereof in the ascending direction may be of smaller cross- ctiona the overall columnar structure undergoing either sharp reduction in cross-section from member to member so as to have a telescopic appearance, or gradual reduction in cross-section from member to member as a result of the tapering of the upper end regions of members by compression. Joining together of successive members can be effected by bolting, spigoting, clamping, welding or use of adhesives depending on the construction and materials of the members. The columnar structure can be hinged to a mounting member of the ground.When thus hinged or of telescopic form, it is particularly easy to lower the upper end of the columnar structure on site to gain access thereto to fit or service functional members to be carried by the structures.

When erecting the columnar structures, they can either be self supporting on their bases, guyed, or their bases can be set in concrete. Owing to their low weight, the columnar structures, or component members thereof, can easily be transported and installed. Because of the open nature of the structure, the fitting of functional members is rendered particularly easy. Thus, clips or bolts may be provided at the upper ends of the columnar structures for the attachment thereto of functional members. Moreover, the incorporation therein of control gear generally accessible through an opening in the base part of the columnar structure, and the passing therethrough of wiring to functional members are rendered easy by the construction of the columnar structure. Moreover, the condition of the wiring from time to time can be readily inspected through the openings in the columnar structure.

For a better understanding of this invention and to show how the same can be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, wherein: Figures 1 to 3 are elevational views of columnar structures embodying this invention; Figure 4 is a transverse cross-section on an enlarged scale through Figure 2 at IV-IV; Figure 5 is a plan view ob a wire mesh sheet for use in the production of a member of a columnar structure embodying this invention; Figure 6 shows the sheet of Figure 5 when rolled into a tubular member; Figures 7 and 8 and 10 and 11 show in section portions of a columnar structure at the position of joining together adjacent members, the members being of telescopic and staggered structure respectively;; Figure 9 is an elevarional view of a portion of a columnar structure in the region at which members thereof are connected together; Figures 12 and 13 are plan and elevational views respectively of a free standing base for a columnar structure; Figures 14 to 17 show different methods of permanently mounting columnar structures on the ground; Figure 18 shows one means by which functional members may be attached to a columnar structure; Figure 19 shows a modified form of upper end of a columnar structure; Figures 20 to 22 show functional members which may be attached to the upper end of a columnar structure embodying this inventoin; Figures 23a and 23b are respectively crosssections through a base region of a columnar structure provided with a connector box; and Figure 24 shows a columnar structure of the type shown in Figure 3 when anchored in concrete and carrying a functional member.

Referring to Figures 1 to 4 of the drawings, the columnar structure embodying this invention can be seen to possess a mesh structure having longitudinally extending wire members 1 and transverse or horizontally ex tending wire members 2 which are welded together at their points of intersection. In the drawings, this material is shown to be used exclusively in the manufacture of columns nar structures. Such use is shown only for illustrative purposes, and, in fact, any of the aforesaid other materials can be used to form the columnar structures. The wire members of illustrated mesh structures may be formed of bright drawn wire welded at every intersection in such manner as to avoid reduction in the tensile strength of the wires. The welds preferably have an average shear strength equal to 80% of the wire strength.If desired, the mesh material may be provided with a galvanised finish, be plastics coated or be painted. Each member making up the columnar structure is formed by rolling on itself a length of welded mesh material. The columnar structure of Fig. 1 uses a plurality of tubular members of the same diameter.

The joins are not visible on Fig. 1. The columnar structure of Figure 2 is made up of a plurality of members 3 which are of decreasing diameter in ascending order. The columnar structure has a telescopic structure with the ends of individual members being seated in or seating the ends of adjacent members sections. Figure 3 also shows a columnar structure made up of members 3 of decreasing diameter in the ascending direction. H- ever, the upper ends of the members either taper or stop short of the next member to allow fixing together of the respective members in a manner to be described hereinafter with respect to Figures 10 and 11. Figure 4 shows a section through a telescopic arrange ment of tubular members at a position at which adjacent members overlap, thereby showing alternating layers of longitudinally and horizontally extending wires.

As will be appreciated from Figure 5, the preferred starting material for use in the construction of columnar structures embodying this invention is simply a rectangular sheet of welded wire mesh. To form a tubular member 3 of the type shown in Figures 2 and 3, the wire mesh sheet is simply rolled on itself to form a tube 4 as shown in Figure 6 and a weld 5 is produced where the edges of the mesh sheet approach each other.

Different methods of joining together ad jacent members are shown in Figures 7 tui 11.

In Figure 7 two tubular members 3 are held together by bolting by means of a bolting arrangement 6 a pair of ring members 6a and 6b welded to the end regions of the respective members. In Figure 8, similar ring members 6a and 6b are clamped together by clamping members 7 having two flanged halves which are bolted together. In contrast to the telescopic fitting of tubular members 3 in Figures 7 and 8, Figure 9 shows a method whereby a columnar structure of uniform diameter throughout its length such as that of Fig. 1, is built up from a plurality of tubular members. For this purpose, the upper end of each member is compressed in a neck region 8 to provide a region 9 whose outer diameter ap proximate s the inner diameter of the next member 3. Fillet welds are then formed where wires of the inner and outer members lie adjacent each other.A similar constructional method can also be used for joining together adjacent members in a telescopic arrangement if the tapering od the end of the lower member is sufficient to allow it to surround or be inserted into the end of the next member which will be of smaller diameter than that possessed by the member having the tapered end.In Figure 10, the ends 10 of adjacent members 3 can be seen to be spaced apart from each other and bridging the two members is a two-part neck member 11 formed of spun steel or as pressings and having a wide lower portion 11a whose external dia- meter approximates the inner diameter of the lower member 3 and to which is welded, a narrower upper portion 11b whose outer diameter approximates the inner diameter of the upper member 3 to which it is welded, each of the portions having a frustoconical section beyond the end of the associated tubular member, the respective frustoconicul sections lying one over the other and being bolted together thereby connecting the tubular members.Figure 11 shows an arrangement in which inner and outer sleeves 12a and 12b of largely cylindrical form but having a short frustocoaical central portion surround the assembled member ends, one being welded to one member end and the other to the other member end. The sleeves are bolted together by two rings of bolts 13.

Figures 12 and 13 show a free standing base 14 for supporting a mesh columnar structure 1 stitch welded to a central seating member 15 thereof. The base 14 is ob cruciform section having a levelling jack 16 at the outer end of each of its limbs 17. Figure 14 shows the bottom end of a columnar structure 1 having a reinforcing ring 18 around its base and carrying a flanged base 19 by means of which the ring is fixed to a concrete foundation 20. For this purpose, projections (not shown) may be provided on the underside of the flanged base 19. Figure 15 shows a modification of the arrangement of Figure 14 in which the flanged base comprises two sections 21 and 22 hinged together at 23.The upper portion 21 is integral with the ring 18 of the columnal structure and it is the lower portion 22 of the flanged base which is fixed to the concrete 20 by means of lugs shown at 24. Such a construction of columnar structure is of particular advantage in that it allows the structure to be lowered so as to lie parallel and adjacent to the ground for attending to the upper end thereof. It is because of the strain which will be placed upon the mount ing of the flanged base in concrete that the lugs 24 will have to be of substantial length in comparison with those which may be utilised in an arrangement of the type shown in Figure 14 so as to ensure that the base portion 22 is not pulled out of concrete when the structure is lowered.It is because of the relatively light weight of a structure embodv- ing this invention that such a hinged mounting is even practicable. Figure 16 shows an arrangement in which the flanged section 21 at the foot of the columnar structure 1 is bolted to the lower section 22 which is carried on a large foundation stub 25 which is set in concrete. It is not however essential for a flanged base to be employed when the structure is to be set in concrete. Thus, as Figure 17 shows, a ring 26 may be fixed to the structure 1 at a position above the bottom end thereof. The structure 1 is then set in concrete 20 in such manner that the ring 26 is positioned at the surface of the concrete.

The manner in which a functional member is affixed to the upper end of a columnar structure embodying this invention may be freely selected in accordance with the nature of the functional member and the strain to which it is likely to be subject in use. For many purposes, the provision of a universal spigot 27 carried by a ring 28 welded to the top end of a structure as shown in Figure 18 is sufficient for this purpose. When the columnar structure is to serve as a lamp standard, an outreach arm 29 carrying a spigot 27 may be affixed to the upper end of the structure 1 (see Figure 19). The outreach arm itself can be formed of the same material as the columnar structure. Figures 20, 21 and 22 show typical pieces of equipment which may be affixed to the upper end of a columnar structure embodying this invention.Thus Figure 20 shows a typical lighting array 30 which may be used for floodlighting purposes.

Figure 21 shows an aerial 31 attached to the spigot 27 at the end of a columnar structure 1. Figure 22 shows a navigational beacon 32 attached to the spigot at the upper end of a columnar structure 1.

The hollow construction of a columnar structure embodying this invention renders the fitting therein of control gear and electric cables particularly simple and moreover such features may be readily viewed through the open structure of the columnar structure. Thus Figures 23a and 23b show a control gear box 33 at the base of a columnar structure 1, being connected to the structure 1 by means of arms 34. A cut out portion of the columnar structure shown as 35 in Figure 23a allows ready access to the control gear box 33. The control gear box 33 possesses a lockable access door 36 which is shown to be open in Figure 23b. Upper and lower conduit entry points (not shown) are provided on the control gear box for admittance of cable 37 thereto.

Finally, a complete mounted and operative columnar structure embodying this invention is shown in Figure 24. The columnar structure t-is od the type shown in Figure3 having a cable 37 passing through the centre thereof to a lighting assembly 38 providing a head load of about 300 Ibs. The cable is centrally disposed in the structure by means of spiders (not shown). At its foot, the columnar structure is attached to a flanged base 19 which is anchored in concrete 20 by means of anchors 39.

Although the tubular members have been described hereinbefore as being formed of sheets of reticular form, they may also be formed of strips of reticular form. In such case, particular strength may be imparted to the columnar structures if the strip form material is wound in helical form.

WHAT WE CLAIM IS:- 1. A columnar structure adapted for cany- ing a member at the upper end of the structure above the ground comprising a plurality of elongate rigid tubular members joined end to end, each tubular member being of a height greater than width in any transverse crosssectional direction and being formed from sheet or strip material of reticular form.

2. A columnar structure as claimed in claim 1 in which the elongate members are formed from sheets of parallel arrays of wires laid in two directions at right angles to each other and welded at their points of intersection.

3. A columnar structure as claimed in claim 1, in which the elongate members are formed of expanded metal sheets.

4. A columnar structure as claimed in claim 1, in which the elongate members are formed of perforated sheet material.

5. A columnar structure as claimed in any preceding claim in which the elongate members are formed of steel.

6. A columnar structure as claimed in claim 3 or 4, in which the elongate members are formed of aluminium.

7. A columnar structure as claimed in claim 4, in which the elongate members are formed of synthetic resin.

8. A columnar structure as claimed in claim 7, wherein the synthetic resin is re inforced with glass fibres or carbon fibres.

9. A columnar structure as claimed in any preceding claim, wherein the elongate members are of circular cross- ction.

10. A columnar structure as claimed in claim 9, wherein the elongate members are formed by coiling said sheet material so that free longitudinally extending ends thereof are brought adjacent each other and forming a longitudinally extending join between said ends.

11. A columnar structure as claimed in any

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. ing of the flanged base in concrete that the lugs 24 will have to be of substantial length in comparison with those which may be utilised in an arrangement of the type shown in Figure 14 so as to ensure that the base portion 22 is not pulled out of concrete when the structure is lowered. It is because of the relatively light weight of a structure embodv- ing this invention that such a hinged mounting is even practicable. Figure 16 shows an arrangement in which the flanged section 21 at the foot of the columnar structure 1 is bolted to the lower section 22 which is carried on a large foundation stub 25 which is set in concrete. It is not however essential for a flanged base to be employed when the structure is to be set in concrete.Thus, as Figure 17 shows, a ring 26 may be fixed to the structure 1 at a position above the bottom end thereof. The structure 1 is then set in concrete 20 in such manner that the ring 26 is positioned at the surface of the concrete. The manner in which a functional member is affixed to the upper end of a columnar structure embodying this invention may be freely selected in accordance with the nature of the functional member and the strain to which it is likely to be subject in use. For many purposes, the provision of a universal spigot 27 carried by a ring 28 welded to the top end of a structure as shown in Figure 18 is sufficient for this purpose. When the columnar structure is to serve as a lamp standard, an outreach arm 29 carrying a spigot 27 may be affixed to the upper end of the structure 1 (see Figure 19). The outreach arm itself can be formed of the same material as the columnar structure. Figures 20, 21 and 22 show typical pieces of equipment which may be affixed to the upper end of a columnar structure embodying this invention.Thus Figure 20 shows a typical lighting array 30 which may be used for floodlighting purposes. Figure 21 shows an aerial 31 attached to the spigot 27 at the end of a columnar structure 1. Figure 22 shows a navigational beacon 32 attached to the spigot at the upper end of a columnar structure 1. The hollow construction of a columnar structure embodying this invention renders the fitting therein of control gear and electric cables particularly simple and moreover such features may be readily viewed through the open structure of the columnar structure. Thus Figures 23a and 23b show a control gear box 33 at the base of a columnar structure 1, being connected to the structure 1 by means of arms 34. A cut out portion of the columnar structure shown as 35 in Figure 23a allows ready access to the control gear box 33. The control gear box 33 possesses a lockable access door 36 which is shown to be open in Figure 23b. Upper and lower conduit entry points (not shown) are provided on the control gear box for admittance of cable 37 thereto. Finally, a complete mounted and operative columnar structure embodying this invention is shown in Figure 24. The columnar structure t-is od the type shown in Figure3 having a cable 37 passing through the centre thereof to a lighting assembly 38 providing a head load of about 300 Ibs. The cable is centrally disposed in the structure by means of spiders (not shown). At its foot, the columnar structure is attached to a flanged base 19 which is anchored in concrete 20 by means of anchors 39. Although the tubular members have been described hereinbefore as being formed of sheets of reticular form, they may also be formed of strips of reticular form. In such case, particular strength may be imparted to the columnar structures if the strip form material is wound in helical form. WHAT WE CLAIM IS:-

1. A columnar structure adapted for cany- ing a member at the upper end of the structure above the ground comprising a plurality of elongate rigid tubular members joined end to end, each tubular member being of a height greater than width in any transverse crosssectional direction and being formed from sheet or strip material of reticular form.

11. A columnar structure as claimed in any

preceding claim, which possesses a height of up to 18 metres.

12. A columnar structure as claimed in any preceding claim, which is capable of supporting a head load of up to 300 Ibs. when subject to a wind velocity of up to 50 metres per second.

13. A columnar structure as claimed in any preceding claim, which carries at its upper end an outreach arm formed of the said sheet or strip material of reticular form.

14. A columnar structure as claimed in any preceding claim, which comprises a spigot for the attachment thereto of said member to be carried above the- ground.

15. A columnar structure as claimed in any preceding claim, wherein the tubular members are of the same cross-sectional form but progressively reduced cross-sectional area in the upward direction.

16. A columnar structure as claimed in claim 15, wherein the tubular members are disposed in a telescopic arrangement.

17. A columnar structure as claimed in any preceding claim, wherein the tubular members are connected together by bolting, clamp- ing, welding or adhesive bonding.

18. A columnar structure as claimed in claim 17, which is of uniform diameter throughout its length, being formed by insertion of one end of one tubular member into the adjacent end of the next tubular member and welding or adhesive bonding thereto, the inserted ends being of reduced diameter with respect to the remainder of the members.

19. A columnar structure as claimed in claim 17, which has been formed by bolting or clamping together members affixed to juxtaposed end portions of the respective tubular members.

20. A columnar structure as claimed in claim 19, wherein the ends of successive tubular members are spaced apart from each other and are of different cross-sectional areas, the tubular members being connected by bolting together collars welded to the respective tubular members.

21. A columnar structure as claimed in claim 20, in which the collars have vertical wall sections adjacent the respective tubular members and terrninate in tapered sections which are juxtaposed and connected together by said bolting.

22. A columnar structure as claimed in claim 20, in which the collars surround both tubular members, have vertical wall sections over the major part of their length but are tapered in a central region in accordance with the difference in cross-section of the tubular members and are bolted together at said vertical wall sections.

23. A coilumnar structure as claimed in any preceding claim which is carried on a free standing base.

24. A columnar structure as claimed in any of claims 1 to 22, the base of which is affixed to a flanged base which is hinged to a base member which is adapted for setting in concrete

25. A columnar structure as claimed in any preceding claim, which carries at its upper end a street light.

26. A columnar structure as claimed in any of claims 1 to 24, which carries at its upper end an outdoor floodlighting arrangement.

27. A columnar structure as claimed in any of claims 1 to 24, which carries at its upper end a radio communication aerial.

28. A columnar structure as claimed in any of claims 1 to 24, which carries at its upper end a navigational beacon.

29. A columnar structure as claimed in any of claims 1 to 24 which carries at its upper end a wind generator.

30. A columnar structure as claimed in any of claims 1 to 24 which carries at its upper end an item of meterological equipment.

31. A columnar structure as claimed in any of claims 1 to 24 which is adapted at its upper end for the support of overhead power transmission lines.

32. A columnar structure substantially as hereinbefore described with reference to the accompanying drawings.