AU2003200119B2 - Fencing - Google Patents

Description

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AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant(s): BHP STEEL LIMITED A.C.N. 000 011 058 Invention Title: INTERMEDIATE FENCE POSTS AND FENCES INCORPORATING

SAME

The following statement is a full description of this invention, including the best method of performing it known to me/us: 2 INTERMEDIATE FENCE POSTS AND FENCES INCORPORATING SAME Field of the Invention This invention relates to fences of the kind comprising a plurality of spaced apart fence posts and barrier panels extending between neighbouring posts and supported thereby.

Fences may include corner posts and end posts, but in normal circumstances the big majority of posts in any fence are intermediate posts, that is to say posts supporting one end of each of two barrier panels extending in substantially opposite directions from the post along the fence line at the post.

The invention is not concerned with special post designs for use at the ends and corners of such fences, although it should be noted that if it is thought to be aesthetically acceptable, two closely adjacent intermediate posts according to the invention, but each supporting an end of only one barrier panel, may be used as a corner post, and a single intermediate post according to the invention, but supporting an end of only one barrier panel, may be used as an end post.

Background Art Typically, fence posts of the kind in question have comprised two, substantially identical post elements, each of which defines a longitudinally extending recess adapted to receive and locate an end of a barrier panel.

Typically, each barrier panel comprises upper and lower rigid rails and in-fill means extending from rail to rail. The in-fill means may be an impervious rigid sheet, a roll formed profiled sheet, a rigid sheet of expanded metal, a plurality of spaced apart pickets, a sheet of woven wire mesh or other substantially planar obstruction to the passage of people or animals between the posts. Under those circumstances it is the ends of the rails that enter the post recesses and are affixed to the posts.

48401 In another embodiment in which the rail ends do not enter the rail recess, the in-fill means are affixed to the posts.

Alternatively, each barrier panel may comprise no more than a rigid, infill sheet, in which event the vertical edge margins of the sheet may enter the post recesses for direct affixture to the posts.

A conventional prior art intermediate post is illustrated by Figures 1 and 2 of the accompanying drawings. Figure 1 is a side elevation of the prior art post when viewed in the direction of the fence line of a fence incorporating the post and Figure 2 is a plan view of the post of figure 1 drawn to a larger scale.

The illustrated prior art intermediate post comprises two, identical, oppositely directed, post elements 7, in the form of roll-formed, coated, sheetsteel channels, each comprising a web 8 and two flanges 9, secured together, web to web, by self-drilling, self-tapping screws 10. In the assembled fence, conventional barrier panels (not shown) supported by the post would have end portions lodged in the channel grooves 11 and would extend in opposite directions along a fence line (indicated by the double headed arrow marked FL in the figure) to neighbouring posts. It will be noted that the webs 8 are fully overlapped, so that the post elements 7 (and therefore the channel grooves 11) are in exact register when viewed in the direction of the fence line at the post.

Probably the most significant load that has to be taken into account in the design of fence components, particularly the posts, is the wind pressure on the fence. This requires the designer to settle on a maximum wind speed that is likely to be imposed on the fence during its lifetime. This will differ with the geographical location of the fence and also on the surrounding local topography and the degree of shelter the fence may receive from adjacent structures or the like. Also the pressure applied to the fence at a particular wind speed will depend on the nature of the in-fill panels.

Hitherto the design of fences has not been very rigorous. Traditionally they have not been fully engineered structures. Over time fence designs have 48401 developed in the market place on the basis that a certain design has "stood the test of time" in particular geographic regions, and therefore designs the same as or closely similar to the time-tested design are deemed to be satisfactory.

To be on the safe side, most people who are responsible for approving a new design are reluctant to accept a proposed design that is seemingly weaker than prior used designs, thus there is a tendency for manufacturers to retain a design that has been proved in high wind locations when transferring to a low wind location. That tendency is reinforced by the desire to use existing tooling for the manufacture of stock components, and may lead to uneconomic, over strong products in low wind locations.

On the other hand designs that have been proved in low wind locations are not suitable for use in high wind locations. Thus a manufacturer wishing to extend the market range of existing low wind area products into a higher wind area has either to strengthen the fence by using additional components (decreasing the post spacing) or redesign the fence components, both of which are expensive options.

Summary of the invention.

An aim of the present invention is to provide for adjustment of the stiffness of the intermediate posts of a fence using the same individual stock components of the posts. This enables in one form of the invention, for an established fence design that has been proved satisfactory in a low wind area, to be used in a higher wind area without the need to reduce the post spacing or modify the barrier panels. This in turn enables the general appearance and configuration of fences, which have been found aesthetically acceptable to consumers in the low wind area, to be retained in the high wind area.

In a first respect, the present invention provides a method of increasing the stiffness of an intermediate fence post of the kind comprising two overlapping post elements, respectively furnished with oppositely directed 48401

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locating means for respective engagement with end portions of barrier panels extending in substantially opposite directions from the post, comprising the step of displacing the post elements transversely with respect to a fence line intersecting the post to ensure that the post elements are in an at least partly outof-register relationship when viewed in the direction of the fence line, and securing the post elements together in said at least partly out-of-register relationship.

Preferably, the method further comprises the steps of; establishing a design wind loading for the fence post; and moving the post elements out-ofregister to increase the stiffness of the post by an amount that is required to accommodate the design wind loading.

In one form, data may be provided and used to establish the amount that the post elements need to be out of register to accommodate the design wind loading. The data typically provides information on at least one performance characteristic of the fence post when the post elements are secured together in at least one, but preferably more, predetermined at least partly out-of-register positions. This data may be stored and supplied to users electronically, or may be in the form of a printed document. In one preferred form, the data comprises a technical data sheet which is provided in conjunction with the post elements.

Preferably the method further comprises the step of using a guide associated with at least one of the post elements to estimate the amount the fence post elements are out-of-register.

A further aspect of the invention provides a fence post of the kind comprising two post elements, respectively furnished with oppositely directed locating means for respective engagement with end portions of barrier panels extending in substantially opposite directions from the post, characterised in that the post elements are in an at least partly out-of-register relationship when viewed in the direction of a fence line intersecting the post, and in that fastening 48401 means secure the post elements together in the at least partly out-of-register relationship.

The invention further provides for a fence incorporating posts according to the above aspect of the invention.

In preferred embodiments each post element is a length of channel, preferably a roll-formed metal channel, comprising a channel web and two channel flanges. In this case the channel flanges serve as the locating means, being adapted to receive end portions of the respective barrier panels between them.

In a first of said preferred embodiments a junction between the web and one flange of one post element makes contact with a junction of the web and one flange of the other post element when the elements are in said at least partly outof-register relationship.

In one form, one post element makes substantially line contact with the other post element. In another form, the junctions between the web and the one flange of the post elements are chamfered, each chamfer forming an abutment surface with the abutment surface of one post element being in contact with the abutment surface of the other post element when the elements are in the at least partly out-of-register relationship.

In a second of said preferred embodiments the webs of the post elements are partly overlapping when the elements are in said at least partly out-of-register relationship.

In a third of said preferred embodiments a flange of one of the post elements partly overlaps a flange of the other post element when the elements are in said at least partly out-of-register relationship.

In a fourth of said preferred embodiments in accordance with said third preferred embodiment, at least the partly overlapping flanges are shaped to form interlocking formations resisting relative movement of the post elements in the direction of the fence line.

48401 7 In one embodiment, a guide is associated with at least one post element and is arranged to assist in estimating the extent the post elements are in out-ofregister relationship. In the arrangement where the post elements are formed from a metal channel, preferably the guide is disposed on the web of the at least one post element. The guide may take various forms, such as notches or markings on the web which are located at equal spacing across the web.

In another form, the web of the fence posts are shaped to form interlocking formations which provide means to interlock the post elements so that they resist relative movement transversely with respect to the fence line.

Further when in this interlocked position, the elements are in the out-of-register relationship. More preferably the web is shaped with the interlocking formations to enable the post elements to be interlocked in a plurality of positions all of which cause the post elements to be in out-of-register relationship.

In a preferred form, the interlocking formation's are formed on the web as a plurality of ribs or corrugations which extend in the direction of the channel.

In a further aspect, the invention relates to a post element for use in a fence post in any of the forms described above.

In a further aspect, the invention is directed to a fence post system which includes; two post elements respectively furnished with oppositely directed locating means for respective engagement with end portions of barrier panels extending in substantially opposite directions from the post, the post elements being configured so that in use, the post elements are able to be secured in at least partly-out-of-register relationship when viewed in the direction of a fence line intercepting the posts, and data providing information on at least one performance characteristic of the fence post when the post elements are secured together in at least one predetermined position, and when in that position, the post elements are in at least partly out-of-register relationship.

48401 8 Preferably the data provides information on the fence post when the post elements are in a plurality of positions each having the post elements in at least partly out-of-register relationship.

Preferably in one form the data may be stored and accessed electronically or may be provided as a printed document. More preferably the data is in the form of a technical data sheet which provided with the post elements.

Brief Description of the Drawings.

As stated earlier, Figures 1 and 2 illustrate a prior art fence post.

By way of example, embodiments of the invention are described in more detail hereinafter with reference to Figures 3 to 9f the accompanying drawings.

Figure 3 is a view similar to figure 2 of a post according to a first embodiment of the invention.

Figure 4 is a view similar to figure 2 of a post according to a second embodiment of the invention.

Figure 5 is a view similar to figure 2 of a post according to a third embodiment of the invention.

Figure 6 is a view similar to figure 2 of a post according to a fourth embodiment of the invention.

Figure 7 is a view similar to figure 2 of a post according to a fifth embodiment of the invention.

Figure 8 is a view similar to figure 2 of a post according to a sixth embodiment of the invention.

Figure 9 is a view similar to figure 2 of a post according to a seventh embodiment of the invention.

48401 Best Mode of putting the Invention into effect.

Those components of the exemplary embodiments illustrated by figure 3 inclusive that are individually the same as components of the prior art post of figures 1 and 2 bear corresponding reference numerals and are not further described below.

The post illustrated by figure 3 comprises two channel sectioned post elements 7. The post elements of this embodiment are fully out-of-register, in that there is no significant overlap of the elements when viewed in the direction of a fence line (indicated by the arrow FL in this and the following figures).

Rather, as is clear from the figure, a junction between the web and one flange of one element 7 makes substantially line contact with a junction of the web and one flange of the other element 7.

In this instance the two post elements may be secured together by an upright row of spaced apart fasteners extending through the posts' line of contact, as indicated by a centreline 12 of the uppermost fastener. Each fastener is preferably a self-drilling, self-tapping screw, but may be a nut and bolt, rivet or other conventional fastening means.

The post illustrated by figure 4 is an example of an embodiment wherein the post elements are partly out-of-register. As is clear from the figure, the webs of the elements 7 are partly overlapping. The two post elements may be secured together by two vertical rows of fasteners indicated by the centre lines 13.

The post illustrated by figure 5 is another example of an embodiment wherein the post elements are fully out-of-register. As is clear from the figure, a flange of one of the elements 7 partly overlaps a flange of the other element 7.

The two post elements may be secured together by two vertical rows of fasteners indicated by the centrelines 14.

The post illustrated by figure 6 is similar to the embodiment of figure except in that its channel-sectioned post elements comprise webs 16 that are somewhat wider than the webs of elements 7 and its flanges 17 are stiffened by 48401 inwardly directed roll-formed ribs 18. Thus, root portions of each of those flanges 17 that are in contact may enter the rib 18 of each of the other of those flanges to provide for an interlock therebetween when the elements are secured together by fasteners indicated by the centrelines 19.

The post illustrated by figure 7, is similar to the embodiment of figure 3.

However in this embodiment, the junction of the web and each flanges of the respective post elements includes a chamfer 20. These chamfers form abutment surfaces with the abutment surface of one element 7 making contact with the abutment surface of the other element. Therefore in contrast to the embodiment of figure 3 where a substantially line contact is provided, in the embodiment of figure 7, contact is made across the chamfered surfaces. This enables the post to post elements to be secured together by two vertical rows of fasteners as indicated by centre lines 22. To incorporate the chamfer 20, the web 23 and flanges 24 are shortened relative to the embodiment to figure 3.

Figure 8 shows a further embodiment of the post. In this embodiment, the web 25 of the post elements 7 are profiled to form a plurality of outwardly directing ribs and troughs 26, 27 respectively). In the illustrated form, the web is generally corrugated however it is to be appreciated that other rib formations may be used. The profiled webs 25 enable the post elements to interlock in a plurality of out-of-register positions and when so interlocked, the post elements are restrained from relative movement in a direction transverse to the fence line.

The advantage of this arrangement is that the fence post 7 can be located accurately in any one of the out-of-register positions provided by the interlocking of various ones of the ribs and troughs in the respective corrugated profiles of the webs 25. As in the earlier embodiments, the post elements 7 are secured together by fasteners as indicated by centrelines 28.

Figure 9 illustrates yet a further embodiment of the post. This embodiment is very similar to that disclosed in figure 4 where the post elements are partly out-of-register with the webs 29 of the element 7 partly overlapping.

48401 11 In the embodiment of figure 9, the webs include markings 30, which in the illustrated form comprise shallow grooves which extend along the length of the 29. These markings provide a guide for aligning the elements 7 in their partly out-of-register relationship. This is achieved by aligning the markings 30 with the flange 31 of the post elements 7. It is to be appreciated that the markings could take any other appropriate form such as notches or surface lines and may be designed to extend the length of the channel or only extend along intermittent sections of that length.

It will be appreciated in respect of all of the illustrated and other embodiments of the invention that the widths of the posts transversely of the fence line are greater than the width of prior art posts by the extent to which the post elements are out-of-register. This repositioning of the material of the post coupled with the fact that the two post elements are united by the fastening means increases the stiffness of the post as a beam in respect of loads, such as wind loads, applied to it in the direction transverse to the fence line.

In conjunction with the post elements 7, data may be generated that provides information on performance characteristics of the fence posts when the post elements are secured together in at least one, but preferably more, predetermined at least partly out-of-register positions. This data may be stored electronically, or may be a printed document. In the preferred format, the data is in the form of a technical data sheet, which is supplied with the post elements.

Using the data, a person erecting the fence will typically first establish the design wind loading for the fence posts and then move the post elements out of register to increase the stiffness of the post by an amount that is required to accommodate the design wind loading. In calculating the amount that is required, reference can be made to the data to obtain the information on the relevant performance characteristic of the fence post corresponding to the post elements being in various at least partly out-of-register relationships.

48401 It will be apparent from the drawings that posts according to the invention are necessarily right and left handed. A post of one hand becomes a post of the other hand if and when it is inverted. This handedness presents no problem when, as is preferred, the method of the invention is effected by on-site assemblers using simple lengths of channel-sectioned material as starting components. However if it is desired to provide the site assembler with more fully pre-fabricated fence components, for example post elements that have been pre-drilled to take the fasteners, or furnished with rail anchorage lugs within the channel grooves, then those components may have to be designed with a degree of redundancy in respect of those details, so that either end of the component may be used equally well as the in-ground end or the top end in the finished fence. If such redundancy is considered undesirable, for example, if the site assembler is provided with post elements, or fully pre-fabricated posts, with dedicated in-ground and top ends, then it would be necessary to provide the site assembler with stocks of right and left handed items.

48401

Claims (19)

1. A method of increasing the stiffness of an intermediate fence post of the kind comprising two overlapping post elements, respectively furnished with oppositely directed locating means for respective engagement with end portions of barrier panels extending in substantially opposite directions from the post, the method comprising the step of displacing the post elements transversely with respects to a fence line intersecting the post so that the post elements are in at least partly out-of-register relationship when viewed in the direction of the fence line, and securing the post elements together in said at least partly out-of-register relationship.

2. A method according to claim 1, further comprising the step of using a guide associated with at least one of the post elements to establish the amount the fence posts are out of register.

3. A method according to claim 1 or 2, further comprising the steps of establishing a design wind loading for the fence post; and increasing the stiffness of the fence post by moving the post elements out of register by an amount that is able to accommodate the design wind loading. 2 o 4. A method according to claim 3, further comprising the steps of; accessing data that provides information on at least one performance characteristic of the fence post when the post elements are secured together in at least one predetermined at least partly out-of-register position; and using the data to establish the amount the post elements need to be out-of-register to accommodate the design wind loading. A fence post of the kind comprising two post elements, respectively furnished with oppositely directed locating means for respective engagement with end portions of barrier panels extending in substantially opposite directions from the post, characterised in that the 48401 post elements are in at least partly out-of-register relationship when viewed in the direction of a fence line intercepting the post, and in that fastening means secure the post elements together in the at least partly out-of-register relationship.

6. A fence post according to claim 5, wherein each post element is a length of channel comprising a channel web and two channel flanges, and wherein the channel flanges serve as the locating means, being adapted to receive end portions of the respective barrier panels between them.

7. A fence post according to claim 6, wherein a junction between the web and one flange of one post element makes contact with a junction of the web and one flange of the other post element when the elements are in the at least partly out-of-register relationship.

8. A fence post according to claim 7, wherein the one post element makes substantially line contact with the other post element.

9. A fence post according to claim 7, wherein the junctions between the web and one flange of the post elements are chamfered, each chamfer forming an abutment surface with the abutment surface of one post element being in contact with the abutment surface of the other post element when the elements are in the at least partly out-of-register relationship. A fence post according to claim 6, wherein the webs of the post elements are partly overlapping when the elements are in the at least partly out-of-register relationship.

11. A fence post according to claim 10, wherein the post element webs are shaped to form interlocking formations that interlock the post elements in at least one position where the elements are at least partly in out-of-register relationship.

12. A fence post according to claim 11, wherein the interlocking 48401 formations are in the form of a plurality of ribs and troughs which extend along the channel web on each of the post elements, and the elements interlock by at least one rib of one element locating within a respective trough on the other element.

13. A fence post according to claim 6, wherein a flange of one of the post elements partly overlaps a flange of the other post element when the elements are in the at least partly out-of-register relationship.

14. A fence post according to claim 13, wherein the at least partly overlapping flanges are shaped to form interlocking formations resisting the relative movement of the post elements in the direction of the fence line. A fence post according to any one of claims 5 to 14, wherein a guide is associated with at least one of the post elements and is arranged to assist in estimating the extent the post elements are in out-of-register relationship.

16. A fence post according to claim 15, when dependent on claim 6, wherein the guide is disposed on the web of the at least one fence post.

17. A fence post according to claim 16, wherein the guide is in the form of markings disposed on the web of the or each post element.

18. A fence post incorporating a fence post according to any one of claims 5 to 17.

19. A post element for use in a fence post according to any one of claims 5 to 17. A fence post system comprising at least two post elements according to claim 19, and data providing information on at least one performance characteristic of the fence post when two post elements are secured together in at lest one predetermined position where the post elements are in at lest partly out-of-register relationship. 48401 16

21. A system according to claim 20, wherein the data provides information on the fence post when the post elements are in a plurality of positions, each having the post elements in at least partly out-of-register relationship.

22. A system according to anyone of claims 20 to 22, wherein the data is provided in a technical data sheet.

23. A fence post substantially as herein described with reference to Figures 3 to 9.

24. A post element substantially as herein described with reference to figures 3 to 9. A fence post system substantially as herein described with reference to figures 3 to 9 Dated this 15T day of January 2003 BHP STEEL LIMITED By their Patent Attorneys GRIFFITH HACK 48401