post

Abstract

A post being elongate and having a proximal end and a distal end, the post comprising a web section extending along a longitudinal axis of the post and four flange sections extending outwardly from and along opposite sides of the web section, wherein the web and flange sections are arranged so that the post has a substantially X-shaped cross-section.

Description

POSTTECHNICAL FIELD

[0001] The present invention relates to a post, and more specifically, but not exclusively, to a post for use in fencing applications.BACKGROUND

[0002] Posts are typically long, sturdy pieces of metal, plastic or timber that can be set upright in the ground and used as supports or markers. In rural applications, such as farming and agriculture, posts are commonly used in fences that delineate fields, paddocks, and properties, and can also contain or segregate livestock. Wire and wire-mesh fences are particularly common in these applications because they are relatively cost effective and straightforward to install and uninstall.

[0003] Most posts used in such applications are made of steel and are roll-formed or extruded to have a Y-shaped profile (i.e., in end view). These posts are typically provided with a pointed end for driving into the ground and a series of spaced holes along one of the three flanges to enable fencing wire to be secured to the post. Such Y-shaped posts may also be referred to as star pickets, star posts, and steelies.

[0004] In use, posts are required to withstand forces, such as those applied by tensioned wire and livestock, without buckling or otherwise failing. The ability of conventional Y-posts to withstand these forces is dependent on the orientation of the post. For example, Y-posts may be installed with the holed flange on the ‘inside’ of the fence, or, alternatively with the holed flange on the ‘outside’ of the fence. When a post is orientated so that the holed flange is on the outside of the fence, the post may have adequate bending strength in response to being pushed by a cow, but may have inadequate strength for responding to a force applied in the opposite direction by a connected tensioned wire, for example.

[0005] Because the loads applied to agricultural fences are variable, there is no agreed upon orientation amongst fence installers that provides optimum strength. This can lead to posts being installed with irregular orientations, which detracts from the integrity and / or visual appearance of the finished fence.

[0006] To address this problem, some installers use ‘maxi-posts’, which are Y-shaped posts that are twice the size of regular Y-shaped posts. Maxi-posts can be used intermittently along afence, or in high-pressure areas, to increase the strength of a fence. Indeed, fences constructed entirely with maxi-posts are strong, but can also be expensive since maxi-posts cost about three times that of a regular Y-post. In addition, maxi-posts still have a Y-profile and therefore suffer from the same limitations as regular Y-posts such as uncertainty about the best orientation and susceptibility to bending.

[0007] The present invention seeks to address or alleviate one or more of the abovementioned problems / limitations of conventional fence posts, or to at least offer a useful alternative.SUMMARY

[0008] In a first aspect, the invention provides a post being elongate and having a proximal end and a distal end, the post comprising a web section extending along a longitudinal axis of the post and four flange sections extending outwardly from and along opposite sides of the web section, wherein the web and flange sections are arranged so that the post has a substantially X-shaped cross-section.

[0009] In some embodiments, the flange sections are provided in the form of a pair of diametrically opposed V-shaped wings that extend along opposite sides of the web section.

[0010] In a second aspect, the invention provides a post being elongate and having a proximal end and a distal end, the post comprising a central web section extending along a longitudinal axis of the post and two diametrically opposed V-shaped flanges extending along opposed sides of the central web section.

[0011] In some embodiments, the web section is substantially planar.

[0012] In some embodiments, the post includes a plurality of apertures. The apertures may be provided along the web section of the post. In some embodiments, the apertures are equally spaced along an upper portion of the web section. In other embodiments, the apertures are unequally spaced along an upper portion of the web section. There may be fourteen apertures along the post. The apertures may be generally circular. In some embodiments, the apertures have a diameter of substantially 10 millimetres.

[0013] In some embodiments, the lowermost of the apertures is spaced away from the distal end of the post. The lowermost of the apertures may be disposed substantially 485 millimetres from the distal end of the post.

[0014] In some embodiments, the web section comprises a notch at the proximal end of the post.

[0015] In some embodiments, the post includes a lower portion provided at the distal end of the post, the lower portion being adapted to pierce and secure the post within a ground surface. The post may further comprise a pointed end for inserting into ground in-use. The pointed end may have an internal angle of substantially 40 degrees.

[0016] In some embodiments, the post is substantially 1650 millimetres in length. A width of the web section may be substantially 18 millimetres.

[0017] In some embodiments, the post formed from steel. The post may include a bitumen dip coating. The post may additionally or alternatively include a paint coating.

[0018] In a third aspect, the invention provides a fence assembly, including at least two posts, wherein each post is a post as described herein, and a wire extending between the posts.

[0019] In a fourth aspect, the invention provides a method of manufacturing a post as described herein, including providing a length of steel and extruding the steel through a die to form the post.

[0020] In some embodiments, the method may additionally include dipping the post in a bitumen coating.BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The invention will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:Figure 1 is an upper perspective view of a conventional Y-post from the prior art;Figure 2 is a top view of the post in Figure 1;Figure 3 is an upper perspective view of a post according to an embodiment of the present invention, the post is shown in-situ;Figure 4 is a lower perspective view of the post in Figure 3;Figure 5 is a first side perspective view of a post according to an embodiment of the present invention, the figure includes break lines illustrating the indefinite dimensions of the post;Figure 6 is a second side perspective view of the post in Figure 5;Figure 7 is a first side view of the post in Figure 5;Figure 8 is a second side view of the post in Figure 7;Figure 9 is a top view of the post in Figure 3;Figure 10 is a bottom view of the post in Figure 3;Figure 11 is a manufacturing diagram showing a side view of a post according to a preferred embodiment of the present invention, the figure shows measurements and dimensions in millimetres;Figure 12 is a top view of the post in Figure 11;Figure 13 is an environmental view of a fence assembly according to an embodiment of the present invention;Figures 14 and 15 are schematic drawings of an I-beam and a T-beam, respectively;Figures 16 and 17 illustrate side load in-line load test conditions of an FEA analysis undertaken on the post of Figure 1; andFigure 18 is a flowchart that schematically outlines a method of manufacturing a post according to an embodiment of the present invention.DETAILED DESCRIPTION

[0022] In the following description, reference is made to accompanying drawings which form a part of the detailed description. It will be readily understood that the aspects of the present disclosure, as generally described herein and illustrated in the drawings may be arranged, substituted, combined, separated and designed in a wide variety of different configurations, all of which are contemplated in this disclosure.

[0023] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, a limited number of the example methods and materials are described herein.

[0024] In addition, certain directional terminology may be used which, unless the context clearly requires otherwise, should be considered with reference to a post as ordinarily installed as part of a fence assembly.

[0025] In general terms, the invention is directed to a post that is elongate and extends between a proximal end and a distal end. The post comprises a web section that extends along a longitudinal axis of the post, and four flange sections extending outwardly from and along opposite sides of the web section. The web and flange sections are arranged so that the post has a substantially X-shaped cross-section. The cross-section may also be considered to resemble a ‘cross’.

[0026] Figures 1 and 2 show an example of a conventional Y-post 50 from the prior art. Conventional Y-posts 50 include three flanges 51a-c, one of which (51a) comprises a plurality of apertures. When being used to construct a fence, Y-posts can be installed with flanges 51b and 51c directed towards the ‘inside’ of a fence, or towards the ‘outside’ of a fence. Since there is no agreed upon orientation amongst fence installers, the orientation of posts may vary along a fence, which decreases the structural and / or visual integrity of the fence. In Figure 2, it can be seen that the cross-section of Y-posts has one plane of symmetry only.

[0027] In stark contrast, posts according to embodiments of the present invention, referred to collectively herein as “X-posts”, provide several advantages when compared to conventional Y-posts from the prior art. For example, since the cross-section of X-posts has two planes of symmetry, rather than one for a conventional Y-post, there is no doubt about how a post should be orientated when installing a fence. Therefore, fences constructed with X-posts have more uniform structural integrity and visual appearance than fences constructed with Y-posts. In addition, because of the additional flanges, X-posts have the same, or similar, bending strength in at least two directions. In other words, X-posts can withstand greater pushing (e.g., from a cow or other large livestock) and pulling (e.g., from a tensioned wire) forces applied to either side of the post when compared to Y-posts. Because of the increased strength of a fence constructed with X-posts, it is understood that the use of expensive maxi-posts may not be obviated.

[0028] Other advantages of the present invention include that X-posts can be formed from a similar amount of material as Y-posts, and can be manufactured using similar manufacturing methods. Therefore, the unit cost of manufacturing X-posts is understood to be similar to the cost of manufacturing Y-posts.

[0029] The X-post will now be described in detail with reference to the accompanying drawings.

[0030] As shown in Figures 3 and 4, a post 10 according to an embodiment of the present invention includes a proximal end 12, a distal end 14, a central web section 16, and flange sections 18a-d. As shown in the Figures, in some embodiments, the flange sections 18a-d are provided in the form of a pair of diametrically opposed V-shaped wings that extend along opposite sides of the web section 16. It is understood that, in other embodiments, the flange sections may be formed differently. The central section, or web section 16 is substantially planar. It is understood that other embodiments may include a web that is non-planar (e.g., cylindrical) while still achieving the advantages of the present invention.

[0031] The post 10 includes a plurality of apertures 20. As shown in the Figures, in preferred embodiments, the apertures 20 are provided along the web section 16 of the post 10. These apertures may be used to thread wire through, or otherwise attach wire to the posts 10, when installing a fence. It is also contemplated, that, in other embodiments, hooks and / or other forms of attachment means may be provided in addition to or in place of apertures 20. The post 10 may also include a notch 26 in the web section 16 at the proximal end 12. This notch is useful when installing a fence, for example it can be used to line up posts along a guide wire, or for easy installation of a barbed-wire line across the top of the fence.

[0032] As shown in Figures 5 to 8, the post 10 includes an upper portion 22 extending from the proximal end 12, and a lower portion 24 extending from the distal end 14. In preferred embodiments, the apertures 20 are provided along the upper portion 22 so that the lowermost aperture 21 is spaced away from the distal end 14 of the post. The apertures 20 may be equally spaced along the upper portion 22 of the web section 16. Alternatively, as shown in the Figures, the apertures 20 may be unequally spaced along the upper portion 22 of the web section 16.

[0033] The lower portion 24 of the post may be adapted to pierce and secure the post within a ground surface. This may include a pointed end 28 for inserting the post into the ground in-use.

[0034] As shown in Figures 7 and 8, the longitudinal axis LA of the post 10 is centrally located and extends along the length of the post 10.

[0035] Figures 9 and 10 are end views of the post 10, when viewed from the proximal end 12 and the distal end 14, respectively. It can be seen that the cross-section includes two planes of symmetry — with both planes extending along the longitudinal axis LA and one being in a vertical direction and one in a horizontal direction.

[0036] Figures 11 and 12 illustrate a preferred embodiment of post 10, which Figures include dimensions in millimetres. As shown, the post 10 includes fourteen apertures 20 (including the lowermost aperture 21), each of which is generally circular with a diameter of 10 millimetres. It isunderstood that, in other embodiments, the apertures 20 need not be circular and, may, for example, be generally elongate in a direction of the longitudinal axis of the post 10. The lowermost aperture 21 is disposed substantially 485 millimetres from a distal end 14 of the post 10. Also shown in the Figures, the pointed end 28 has an internal angle of substantially 40 degrees. The thickness of the flanged sections 18a-d is 3 millimetres and the central web section 16 has a thickness of 5 millimetres and a width of 18 millimetres. The overall length of the post is substantially 1650 millimetres.

[0037] It is to be understood that various embodiments having different dimensions to those shown in Figures 11 and 12 are possible and may still achieve the advantages of the invention. For example, embodiments with a web section 16 that is longer than 18 millimetres, such that the post no longer has an X-shaped cross-section, may still be within the scope of the invention. Moreover, the overall length of the post and the spacing and number of apertures may vary.

[0038] As shown, the post 10 is formed from steel. It is understood that the post 10 may also include a bitumen dip coating and / or a paint coating. Such coatings can be used to provide protection to the steel post, for example to prevent rust. Paint coatings may be used to enhance the visibility of the posts for certain conditions. Paint coatings may be applied to only a portion of the post as a guide, for example to show a preferred depth for inserting the post into the ground, or to provide an installer with a marker for how high they can raise an insertion tool (e.g., a driver) while inserting a post into the ground. The post 10 may also be formed from other materials such as plastics or metal alloys. The material may be chosen based on the desired mechanical properties of the post, which in turn, will depend on the end application of the post. For example, a post designed for use in a fence may require greater strength than a post used as a marker or for holding a sign.

[0039] Figure 13 shows a schematic illustration of a fence assembly 40. The fence assembly 40 includes at least two posts 10 and at least one wire 30 extending between the posts. As can be seen in the figure, the fence assembly may include a plurality of wires 30. Importantly, all posts in the fence assembly are orientated similarly.

[0040] To illustrate the improved bending properties of X-posts compared to conventional Y-posts, Figures 14 and 15 provide schematic diagrams of an I-beam and a T-beam, respectively. For this analysis, the I-beam is used as an approximation for an X-post, and the T-beam is used as an approximation for a Y-post.

[0041] Bending stress, a, which indicates the ability of a beam to withstand bending forces, at a given location along a beam (or post) can be calculated as:where M is the bending moment at the location of interest, I is the area moment of inertia of the beam’s cross-section, and y is the distance from the neutral axis of the beam to the point of interest along the height of the cross-section. From Equation (1), it can be seen that the bending stress, o, is inversely proportional to the area moment of inertia, I (i.e., a <x / -1).

[0042] In the following analysis, the dimensions shown in Figure 12 are adopted for both the I-beam and T-beam cross-section dimensions (i.e., h = 3 mm, / 7= 18 mm, b = 5 mm, and B = 36 mm).

[0043] For an I-beam, the area moment of inertia about the x-axis and y-axis can be calculated using Equations 2 and 3, respectively:Ixx_, = H3b / 12 + 2[h3B / 12 + hB(H + h)2 / 4], (2) Iyy_, = b3H / 12 + 2(B3h / 12). (3)

[0044] Similarly for a T-beam, the area moment of inertia about the x-axis and y-axis can be calculated using Equations 4 and 5, respectively: / H\2 / h IXX-T= bH[yc--} + bH3 / 12 + hB yH + — — ycj + h3B / 12, (4)Iyy-T= b3H / 12 + B3h / 12. (5) where yc= [( / 7 + h / 2)hB + H2b / 2] / A, and A = Bh + bH.

[0045] The values calculated from Equations (2)-(5) are shown in the table below.Second momentI-beam T-beamof areaIxx2.64 x 10“8m40.79 x 10“8m4Iyy 2.35 x 10“8m41.18 x 10“8m4

[0046] It can be seen that:Ixx-j ~3.3IXX-T, andIyy-i ~ - Iyy-T-

[0047] As mentioned above, since o oc / -1, the bending stress is much lower in the I-beam (which approximates the X-post) than in the T-beam (which approximates the Y-post) for a given bending moment, M, and distance from the neutral axis, y. In other words, for an X-post and a Y-post made from similar materials, with similar dimensions and subject to a similar bending force, the bending stress in the X-post is less than in the Y-post. Therefore, the X-post is less likely to fail due to bending.

[0048] Referring now to Figures 16 and 17. Finite element analysis (FEA) models were prepared to compare the strength of the X-post against a conventional Y-post. Two load cases were analysed: (i) side loading designed to simulate bending loads on the post due to force being applied to the side of a fence and (ii) in-line loads design to simulate the bending load on the post due to a force being applied in-line with the fence. The side load condition (Figure 16) may, for example occur if an animal or vehicle pushed on the side of the fence while the in-line load condition (Figure 17), although less common, could occur if a tree or heavy object falls onto the fence from above.

[0049] The finite element analysis modelling, for both the X-post and a conventional Y-post, was performed on a 1.0 m long post section of hot rolled mild steel, with an assumed yield strength of 180 MPa. The base of the post was assumed to be fully fixed (that is 0 degrees of freedom) and a load (F) was applied at the top of the post section. The magnitude of the applied load (F) was increased until the onset of yield was observed.

[0050] The results both load cases are shown in the table below.Y-Post X-PostSide Load Force at yield 120 N 520 NBaseline 100% 433%In-Line Load Force at yield 105 N 250 NBaseline 100% 238%Mass Per unit length 1.43 kg 2.34 kgBaseline 100% 164%

[0051] A method 100 of manufacturing a post 10 will now be described with reference to Figure 18.

[0052] In an initial or providing step 110, a length of steel, which is sometimes known as a blank, is provided. In a further or extruding step 120, the length of steel is extruded through a die to form the post. Other steps may include punching, drilling or otherwise forming the apertures20, 21 and forming the pointed end by cutting or rolling the distal end 14 of the post 10. In a further or dipping step 130, the extruded post may be dipped in a bitumen coating and / or painted to achieve the advantages as mentioned above.

[0053] It is to be understood that a post 10 according to an embodiment of the present invention can, alternatively, be manufactured using other methods, such as roll-forming.

[0054] Summarily, posts described herein provide several advantages and improvements over known, existing posts, and have particular application as fence posts for wire and wire mesh fences. For example, there is no doubt about the orientation in which X-posts should be installed. This saves an installer time and can also improve the structural integrity and visual appearance of a fence. Moreover, because the bending strength of an X-post is improved, when compared to a conventional Y-post, strengthening posts such as maxi-posts may not be required for a given fencing application. Finally, the posts are suitable for use with existing tools that are commonly used for installing and uninstalling fence posts.

[0055] The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavor to which this specification relates.

[0056] Throughout this specification and the claims which follow, unless the context requires otherwise, the word ‘comprise’, and variations such as ‘comprises’ and ‘comprising’, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.LEGEND10 Post12 Proximal end of the post14 Distal end of the post16 Web section18a-d Flange sectionsLA Longitudinal axis20 Apertures21 Lower-most aperture22 Upper portion24 Lower portion26 Notch at top of post28 Pointed end30 Wire40 Fence assembly50 Y-post (prior art)51a-c Flange sections100 Method of manufacturing a post 110 Providing step120 Extruding step130 Dipping step

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A post being elongate and having a proximal end and a distal end, the post comprising a web section extending along a longitudinal axis of the post and four flange sections extending outwardly from and along opposite sides of the web section, wherein the web and flange sections are arranged so that the post has a substantially X-shaped cross-section.

2. The post of claim 1, wherein the flange sections are provided in the form of a pair of diametrically opposed V-shaped wings that extend along opposite sides of the web section.

3. A post being elongate and having a proximal end and a distal end, the post comprising a central web section extending along a longitudinal axis of the post and two diametrically opposed V-shaped flanges extending along opposed sides of the web section.

4. The post of any one of claims 1 to 3, wherein the web section is substantially planar.

5. The post of any one of claims 1 to 4, wherein the post includes a plurality of apertures.

6. The post of claim 5, wherein the apertures are provided along the web section of the post.

7. The post of claim 5 or claim 6, wherein the apertures are equally spaced along an upper portion of the web section.

8. The post of any one of claims 5 to 7, wherein the apertures are generally circular.

9. The post of any one of claims 5 to 8, wherein the lowermost of the apertures is spaced away from the distal end of the post.

10. The post of claim 9, wherein the lowermost of the apertures is disposed substantially 485 millimetres from the distal end of the post.

11. The post of any one of claims 1 to 10, wherein the web section comprises a notch at the proximal end of the post.

12. The post of any one of claims 1 to 11, wherein the post includes a lower portion provided at the distal end of the post, the lower portion being adapted to pierce and secure the post within a ground surface.

13. The post of any one of claims 1 to 12, further comprising a pointed end for inserting into ground in-use.

14. The post of claim 13, wherein the pointed end has an internal angle of substantially 40 degrees.

15. The post of any one of claims 1 to 14, wherein the post formed from steel.

16. The post of any one of claims 1 to 15, wherein the post includes a bitumen dip coating.

17. The post of any one of claims 1 to 16, wherein the post includes a paint coating.

18. A fence assembly, including at least two posts, wherein each post is a post according to any one of claims 1 to 17, and a wire extending between the posts.

19. A method of manufacturing a post according to any one of claims 1 to 17, including providing a length of steel and extruding the steel through a die to form the post.

20. The method of claim 19, further including dipping the post in a bitumen coating.

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