AU2020299807A1 - Agricultural fencing - Google Patents

Abstract

A hollow blank 910 for a hollow fence post 920 is disclosed. In addition, a fence post extender 40, 140, 240, 340, 540, 740, 840 is disclosed. A joiner bracket 1342 for a fence post extender is also disclosed. The fence post extenders are provided with an open mouth slot 45 which is able to slide over the ears 113, 114 and part of the stem 112 of a conventional star picket 11 without disrupting the upper wires 17, 22 of a conventional inclusion agricultural fence. The fence post extenders enable conventional waist high inclusion fencing to be converted into head high exclusion fencing including high wires 412, 413, 414.

Description

Agricultural Fencing

Field of the Invention

The present invention relates to agricultural fencing and, in particular, to agricultural fence posts and extensions for agricultural fence posts.

Background Art

In Australia, traditional agricultural fencing has been concerned with retaining domestic stock, primarily cattle and sheep, within the property upon which these animals graze. Such a fence is approximately waist high and has generally been formed from both steel fence posts (termed“star pickets”) and wooden fence posts. Between each pair of wooden fence posts are typically 4 or 5 star pickets. At the end of each fence line is a much heavier wooden post termed a strainer post. Also included within most fences is a gate to enable access to, and egress from, a paddock enclosed by the fence. Such fencing is now referred to as inclusion fencing.

In recent years a new type of fencing, referred to as exclusion fencing, has been developed. Such fencing uses mesh which extends to approximately 2 meters in height. Exclusion fencing is intended to exclude kangaroos, wallabies and feral deer which are able to jump over traditional fencing. In addition, exclusion fencing is intended to exclude burrowing animals such as feral pigs and wombats. Although kangaroos and wallabies are capable of jumping over an inclusion fence, normally this is only done in extremis and, as a rule, kangaroos and wallabies normally burrow under, or push their way through, a traditional fence.

There is a very significant and substantial investment in traditional inclusion fencing. The cost of exclusion fencing is high (both in terms of material costs and installation costs) and so many property owners baulk at the expense of such exclusion fencing. Accordingly, it would be desirable to achieve most of the benefits of exclusion fencing by modifying existing traditional inclusion fencing.

Fence posts have traditionally been made from timber or steel. Both of these materials suffer from various problems. Timber, and particularly pine, is not particularly strong. Timber is also likely to suffer attacks from bush fires, borers, fungus, mould, termites and the like. In addition, timber is not homogenous and so suffers from weak points at locations where there are knots, or other imperfections.

Similarly, steel suffers from corrosion generally as it rusts in the atmosphere. However, in some localities there are acidic soils which can rapidly corrode steel fence posts, particularly when such soils are moist. For this reason it is known to galvanise steel posts, however, this is a relatively expensive manufacturing step.

Furthermore, on many farms horses are retained within fenced paddocks. If steel posts are used in the fencing for such paddocks, then horses are liable to damage themselves against such steel posts, particularly if they take fright as a consequence of lightning, for example.

Genesis of the Invention

The Genesis of the present invention is a desire to improve agricultural fencing and agricultural fence posts so as to, at least to some extent, ameliorate the above- mentioned problems.

Summary of the Invention

In accordance with a first aspect of the present invention there is disclosed an elongate fence post, or an elongate fence post extender, having an upper end and a lower end with a hollow interior extending between said ends, said upper end being adapted to be connected with a fence wire, and said hollow interior being of an at least partially Y-shaped configuration.

Preferably the elongate fence post, or elongate fence post extender, has an exterior surface which is substantially Y-shaped.

Preferably the elongate fence post extender is for extending the height of a star picket fence post having a substantially Y-shaped cross sectional shape formed by a stem and a pair of arms having a substantially V-shaped configuration, and the elongate fence post extender has the lower end which is provided with a longitudinally extending open mouth slot dimensioned to pass over the star picket arms with the open mouth receiving a portion of the stem adjacent said arms.

Preferably be open mouth slot does not extend into the upper end.

Preferably be open mouth slot has a substantially V-shaped configuration.

Preferably be upper end has at least one transverse aperture shaped to receive a fencing wire or a tie wire for a fencing wire.

In accordance with a second aspect of the present invention there is disclosed a fence post extension for extending the height of a star picket fence post having a substantially Y-shaped cross sectional shape formed by a stem and a pair of arms having a substantially V-shaped configuration, said fence post extension comprising an elongate member having two ends, one of said ends being adapted to be connected with a fence wire and the other of said ends having a longitudinally extending open mouth slot dimensioned to pass over said star picket arms with said open mouth receiving a portion of said stem adjacent said arms.

Preferably the open mouth slot does not extend into the one end.

Preferably the open mouth slot has a substantially V-shaped configuration.

Preferably the one end is substantially solid.

Preferably be one end has a generally Y-shaped configuration with a stem and a pair of arms.

Preferably the stem of the one end has one or more apertures shaped to receive fencing wire.

Preferably the open mouth slot extends between the ends. Preferably be open mouth slot extends the length of said extension.

Preferably be one end is hollow.

Preferably be one end does not have any enclosed cavity.

Preferably the one end has a substantially Y-shaped configuration with a stem and a pair of arms.

Preferably the stem of the one end has one or more apertures shaped to receive fencing wire.

Preferably the extension is substantially a hollow cylinder.

Preferably the open mouth slot is formed by a rolled sheet metal bracket connected to the one end.

Preferably the extension is fabricated from a material selected from the class consisting of steel, aluminium and plastics.

Preferably the extension is fabricated by extruding or moulding.

Preferably the extension is truncated and is preferably coloured to assist sighting by horses.

In accordance with another aspect of the presentation there is disclosed a fence post for an agricultural fence, the fence post having a conventional Y-shaped

configuration, being fabricated from plastics material, and having a hollow interior.

Preferably the hollow interior is also substantially Y-shaped.

Preferably the hollow interior has a substantially constant wall thickness. Preferably the fence post has a pointed lower end.

Preferably the pointed lower end is formed by cutting the fence post at an angle to its longitudinal axis.

Alternatively, the fence post has its pointed lower end is formed by a separate component joined to the fence post.

Preferably the separate component is moulded and has a tip at one end and a stem at the other end, said stem being engageable with the hollow interior of said fence post.

Preferably the fence post has a plurality of apertures extending transversely therethrough.

In accordance with a still further aspect of the present invention there is disclosed a fence formed from one or more of the above fence posts or the above fence post extensions.

In addition, there is also disclosed a method of fabricating an elongate fence post, or an elongate fence post extender, the method comprising the step of extruding a hollow substantially Y-shaped fence post or fence post extender.

Also disclosed is a method of attaching a fence post extension to a star picket fence post having a substantially Y-shaped cross-sectional shape formed by a stem and a pair of arms having a substantially V-shaped configuration, said method comprising the step of sliding an open mouth slot of said fence post extension over said star picket arms and engaging said open mouth with a portion of said stem adjacent said arms.

Brief Description of the Drawings

Several embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Fig. 1 is a long distance perspective view of a conventional prior art fence having metal“star picket” fence posts intermediate wooden fence posts,

Fig. 2 is a close range perspective view of the conventional prior art fence of

Fig. 1,

Fig. 3 is a perspective view of an extruded plastics blank from which the fence post of a first embodiment is fabricated,

Fig. 4 is a truncated perspective view of the fence post of a first embodiment, Fig. 5 is a truncated side elevation of the fence post of Fig. 4,

Fig. 6 is a truncated plan view of the fence post of Fig. 4,

Fig. 7 is a truncated inverted plan view of the fence post of Fig. 4,

Fig. 8 is a bottom end view of the fence post of Fig. 4,

Fig. 9 is a top end view of the fence post of Fig. 4,

Fig. 10 is a cross-sectional view taken along the line X - X of Fig. 5,

Fig. 11 is a perspective view from above of a moulded tip for a fence post of a second embodiment,

Fig. 12 is a perspective view from below of the tip of Fig. 11,

Fig. 13 is a truncated perspective view of the lower end of the fence post of the second embodiment incorporating the tip of Figs. 11 and 12,

Fig. 14 is a side elevational view of a fence post of a third embodiment incorporating slide in transverse apertures,

Fig. 15 is a perspective view from above of the fence post of Fig. 14,

Fig. 16 is an exploded schematic perspective view of a prior art fence post extension arrangement,

Fig. 17 is a view similar to Fig. 2 but illustrating a further embodiment of the present invention,

Fig. 18 is a plan view of the extended fence post of Fig. 17,

Fig. 19 is a truncated side elevation of the fence post extension of Fig. 17,

Fig. 20 is a plan view of the slotted lower end of the fence post extension of

Fig. 17,

Fig. 21 is an inverted perspective view of the slotted lower end of the fence post extension of Fig. 17,

Fig. 22 is an end view of the slotted lower end of the fence post extension of

Fig. 17, Fig. 23 is a perspective view of a fence post extension of another embodiment mounted on a smaller size star picket,

Fig. 24 is a similar perspective view of the fence post extension of the second embodiment mounted on a larger size star picket,

Fig. 25 is a plan view in the direction A of Fig. 23,

Fig. 26 is a similar plan view but in the direction B of Fig. 24,

Fig. 27 is a truncated perspective view of an extrusion from which the fence post extension of Fig. 23 can be fabricated,

Fig. 28 is a truncated perspective view of a length of the extrusion of Fig. 27 modified so as to form the fence post extension of Fig. 23,

Fig. 29 is a view of a pulldown tool used to assist in the application of the fence post extension to the star picket,

Fig. 30 is a perspective view showing the use of a tool handle such as a screwdriver handle in the removal of the fence post extension from a star picket,

Fig. 31 is a perspective view of a fence post extension of a still further embodiment mounted on a smaller size star picket,

Fig. 32 is a similar perspective view of the fence post extension of Fig. 31 mounted on a larger size star picket,

Fig. 33 is a transverse cross-sectional view through the extrusion used to form the fence post extension of Fig. 31,

Fig. 34 is a plan view in the direction C of Fig. 31,

Fig. 35 is a similar plan view but in the direction D of Fig. 32,

Fig. 36 is a truncated perspective view of an extrusion from which the fence post extension of Fig. 31 can be fabricated,

Fig. 37 is a truncated perspective view of a length of the extrusion of Fig. 36 modified so as to form the fence post extension of Fig. 31,

Fig. 38 is a perspective view of a fence post extension of yet another embodiment mounted on a star picket,

Fig. 39 is a similar perspective view of the fence post extension of Fig. 38 embodiment mounted on the star picket,

Fig. 40 is a plan view in the direction E of Fig. 38,

Fig. 41 is a similar plan view of the unattached rolled sheet steel bracket, Fig. 42 is a truncated perspective view of the unattached rolled sheet steel bracket of Fig. 41,

Fig. 43 is a perspective view of a fence post extension of a still further embodiment mounted on a star picket,

Fig. 44 is a similar perspective view of the fence post extension of Fig. 43 mounted on the star picket,

Fig. 45 is a plan view in the direction F of Fig. 43,

Fig. 46 is a truncated perspective view of the fence post extension of Fig. 43, Fig. 47 is a perspective view showing the mounting of a fence post extension onto a wooden post,

Fig. 48 is a perspective view of another mechanism for mounting a fence post extension onto a wooden post,

Fig 49 is a plan view of the mechanism of Fig. 48,

Fig 50 is a perspective view of the connector plate illustrated in Figs. 48 and 49,

Fig. 51 is an end view of the connector plate of Fig. 50,

Fig. 52 is a side elevation of a vertically extended fence fabricated from a waist high fence using the fence post extensions of Fig. 28,

Fig. 53 is a perspective view of a curved fence post extension of a still further embodiment,

Fig. 54 is a similar perspective view of a fence post extension curved in the opposite sense,

Figs. 55-58 correspond to Figs. 38-41 but illustrate a joiner bracket of a still further embodiment,

Fig. 59 is a truncated plan view of a sheet of galvanise steel from which a fence post extender of another embodiment is rolled,

Fig. 60 is a transverse cross-sectional view through the rolled fence post extender made from the blank of Fig. 59,

Fig. 61 is a perspective view from above of the rolled fence post extender made from the blank of Fig. 59, and

Figs. 62 and 63 are each a perspective view from a different angle of the rolled fence post extender of Fig. 61. Detailed Description

As seen in Figs. 1 and 2, a traditional inclusion fence 10 generally takes the form of 4 or 5 metal star picket posts 11 which are spaced apart along the fence line between a pair of wooden posts 20. As best seen in Fig. 2, the star picket 11 has a generally Y- shaped configuration formed from a stem 12 and a pair of V-shaped arms 13, 14. At the very top of the star picket stem 12 is a tang 15 formed by a U-shaped slot 16. Below the slot 16 are a series of through holes located approximately centrally in the stem 12.

The most common traditional arrangement is for the uppermost wire 17 to be barbed wire 18. This wire passes through the slot 16 and is held in position by a tie wire 19 which passes through the uppermost hole 21 and is wrapped around the uppermost wire 17 on either side of the slot 16.

The next wire, which can conveniently be termed the penultimate wire 22, passes through the penultimate hole 23 and is a plain wire.

Next comes a second barbed wire 24 which passes to one side or the other of the star picket 11 since the barbs of the barbed wire 24 will not permit the barbed wire to be passed through the corresponding hole 25. Instead, another tie wire 29 passes through the corresponding hole 25 and has either end wrapped around the barbed wire 24. This tie wire 29 holds the second barbed wire 24 in position against the star picket 11 at the desired height from the ground.

Next comes the top wire 27 which passes through its corresponding hole 28. Netting 30 (which can take various forms such as hinged wires, locked wire mesh and rabbit netting) is positioned to one side or the other of the star picket 11 and is secured to the top wire 27 by means of netting clips 31.

In the arrangement illustrated, both the second barbed wire 24 and the netting 30 pass on the stem side of the star picket 11. It is possible for either or both of these wires to pass on the opposite side of the star picket 11. In one common modification, not illustrated, shorter star pickets can also be used, in which case the penultimate wire 22 is not used and instead the penultimate wire is the barbed wire 24. That is to say, there are two barbed wires above the top wire 27 and no penultimate plain wire 22.

The star picket 11 suffers from several disadvantages including its susceptibility to rust and corrosion, and its inherent weight, being fabricated from steel. In order to at least ameliorate these disadvantages, as seen in Fig. 3, a generally Y-shaped hollow plastic extrusion 910 is preferably formed from PVC, polypropylene, glass filled nylon, and the like. The extrusion 910 forms a blank from which the fence post 920 of a first embodiment illustrated in Fig. 4 is fabricated.

After the initial extruding step, the plastic extrusion 910 is cut to length and then cut so as to form a point at its lower end 921. In addition, a slot 923 is preferably formed in the post’s upper end 922. In addition, the fence post 920 is preferably provided with a series of spaced apart apertures 925 through which wire, or wire retaining clips, can be inserted. As best seen in Figs. 8-10, the fence post 920 has a hollow interior 928 which reduces the weight and the amount of plastic in the fence post 920 and which, by virtue of its shape, contributes to the overall strength of the fence post 920.

In particular, the fence post 920 has excellent strength in resisting longitudinal torsional forces and bending forces. It is capable of being rammed into soil using a fence post driver suitable for conventional steel star pickets. In addition, because it is fabricated from plastics, it is a good insulator and is therefore useful as a fence post for electric fencing. Such fence posts 920 cannot rust or be corroded. In addition, it can be coloured in any colour and so can be coloured white, for example, so is to be easily sighted by horses. Finally, the plastic can include an appreciable percentage of recycled material thereby reducing the cost of the fence post 920 and also contributing to recycling for the benefit of the wider community.

In another embodiment illustrated in Figs. 11-13, an injection moulded tip 950 is provided with a stem 951 which is shaped generally in the manner of a star picket and thus easily mates with the hollow interior 928 of the post 920. In this way, rather than having the lower end of the post 920 cut to form a sharp point, instead the moulded tip 950 can be inserted, preferably with a glue or other adhesive, into the lower end of the extruded fence post 920.

Turning now to Figs. 14 and 15, if desired the fence post 920 can be provided with a plurality of shaped transverse apertures 960 which have a narrow opening 961 which enables a wire to be passed through the opening 961 and thereby retained in the aperture 960.

As seen in Fig. 16, it is known in Australia to extend the height of star pickets 11 by means of a rarely used arrangement 33 of the general type disclosed in Australian Patent No 705,040 (11413/95). This arrangement 33 takes the form of a Y-shaped hollow steel sleeve 34 and a short length of substantially conventional star picket 35. The upper end of the sleeve 34 is crimped or welded to the lower end of the star pickets 35 so as to join the two components in a permanent connection (not illustrated).

In addition, the sleeve 34 has two holes in the form of an upper sleeve hole 37 and a lower sleeve hole 38 which are spaced apart by a distance corresponding to the distance between the holes 21 and 23 of the star picket 11 of Fig. 2.

In use, the arrangement of Fig. 16 has to be secured to the top of each of the star pickets 11 in the traditional fence. In order to do this, firstly the penultimate wire 22 is completely removed. Next the tie wire 19 is undone and the barbed wire 18 moved away from the star picket 11. Next the sleeve 34 is slid over the upper end of the star picket. Then a new tie wire 19 is passed through the holes 21 and 37 and secured to the barbed wire 18 in the usual fashion. Also a new penultimate wire 22 is passed through the holes 23 and 38 so as to re-fashion the traditional fence. This activity secures the sleeve 34 to the star picket 11. Thereafter, further wires as desired, are passed through the star pickets 35, or connected to the star pickets 35. The result is a fence which extends to a height of approximately 2 meters. However, the connection of the sleeve 34 to the star picket 11 is labour intensive and cumbersome. A further disadvantage of this arrangement is that the tang 15 of the star picket 11 is often bent out of the vertical (as illustrated in Fig. 2 and as illustrated in broken lines in Fig. 16). This hinders the ability of the sleeve 34 to be slid over the top of the star picket 11. In particular, the tang 15 is often deformed by a sledgehammer if the star picket 11 has been driven by the sledgehammer rather than a post driver. This deformation results in the tang 15 being work hardened and so it is very difficult to straighten the tang 15.

Turning now to Figs. 17 - 22, a first embodiment of a fence post extension 40 is illustrated which is preferably moulded or extruded from plastics materials such as PVC, polypropylene, or glass reinforced nylon but can also be fabricated from metal such as aluminium.

As best seen in Fig. 17, the fence post extension 40 of the first embodiment has an upper end 41 which generally mimics the upper end of a conventional star picket, and a lower end 42 which is slotted and is able to slide onto the conventional star picket 11.

The upper end 41 has a stem 112 and two V-shaped arms 113 and 114. It also has a slot 116 and a series of holes 121, 123, 125, 128, etc. As seen in Figs. 17 and 18, the upper end 41 lies above the star picket 11.

As best seen in Fig. 21, the lower end 42 has an open mouth 44 which leads into a V- shaped slot 45. The open mouth 44 is dimensioned to receive that portion of the stem 12 of the star picket 11 which is close to the V-shaped arms 13, 14. Similarly, the slot 45 is dimensioned to receive the V-shaped arms 13, 14. As a consequence, the lower end 42 is able to be slid onto the star picket 11 by engaging the V-shaped arms 13, 14 and a portion only of the stem 12.

As best seen in Figs 17, 19 and 21, the lower end 42 is able to be slid onto the star picket 11 so that the lower end of the stem 112 engages the upper end of the star picket 11. Preferably this engagement results in mild deformation of the sides of the slot 45. As a consequence, there is a friction fit between the lower end 42 and the star picket 11. If desired, this friction fit can be increased by the provision of protrusions 47 (Fig. 20) on the interior surfaces of the slot 45.

It will be apparent to those skilled in the fencing arts that the lower end 42 of the fence post extension 40 is able to be slid into position as illustrated in Fig. 17 without having to undo or rearrange any of the wires of the traditional inclusion fence. Also, whether the tang 15 is bent, or not, is irrelevant. Once the fence post extension 40 is in the position illustrated in Fig. 17, one or more wires are able to be positioned on the upper end 41 so as to create a fence (illustrated in Fig. 52) having a height in the vicinity of 2 meters. Since both domestic stock and wild animals are not tall enough to push against these elevated wire(s), it or they can be plain wire(s) rather than barbed wire(s). In addition, these elevated wire is 412, 413, 414 etc. are able to be electrified but need not be.

In respect of animals such as deer, it is desirable to have a plurality of wires at a height above that of the traditional fence since the intention is that the fence jumping deer be“caught” and elastically re-bounded by the fence. However, in respect of animals such as kangaroos, it can be desirable to have only a single wire at a height above that of the traditional fence. Under these circumstances, the kangaroo attempting to jump over the fence has a centre of gravity above the single wire, but its “feet” pass below the single wire. As a result, its“ankles” are restrained by the wire and the motion of the kangaroo rotates the kangaroo about the“ankles” often resulting in a broken neck or similar fatal injury. In both cases, in most instances, the extended fence provides the necessary visual deterrent to jumping.

Turning now to Figs. 23 - 30, a hollow fence post extension 140 of a second embodiment of the present invention is illustrated. The fence post extension 140 is extruded from plastics or aluminium and is then cut to length. In addition, the extrusion is docked at its lower end so as to form an open mouth 144 to a slot 145 both of which extend along only the lower length of the extension. It will be seen from Figs. 25 and 26 that the slot 145 is provided with a plurality of inwardly projecting longitudinally extending fins or ribs 147. The star pickets on Australian farms have been produced by various manufacturers over the years and thus are not all exactly the same size even though they are of substantially similar dimensions. It will be seen that the truncated star picket 11 A of Figs. 23 and 25 is slightly smaller than the star picket 1 IB of Figs. 24 and 26. Whilst the shape of the slot 145 closely follows the profile of the star picket 1 IB, the profile of the star picket 11 A is slightly different. However, the presence of the open mouth 144 enables the fence post extension 140 to flex and accommodate the shape of the star picket. In addition, protrusions in the form of the ribs 147 are able to be deformed by coming into contact with the star pickets and thus ensuring a good frictional fit between the fence extension 140 and the star picket, notwithstanding variations in its shape and dimensions.

Fig. 27 illustrates the extrusion 910 of Fig. 3 from which the fence post extension 140 can be fabricated. Firstly the extruded material is cut to length. Then, as seen in Fig. 28, each length is docked so as to form the open mouth 144 and slot 145, and punched so as to form the slot 116 and holes 121, 123, 125 and 128. This results in the finished fence post extension 140 as illustrated in Figs. 24 and 28.

In order to assist in engagement of the fence post extension 140 with the star picket 11, a pulldown tool 151 as seen in Fig. 29 is provided which is bent from steel wire or rod so as to form two arms 152 and a pair of handles 153. Located between the arms 152 is a crosspiece 154 which is dimensioned to engage with the slot 116 of the fence post extension 140. With the crosspiece 154 engaged with the slot 116, the fencer pulls downwardly on the handles 153 so as to force the fence post extension 140 into engagement with the star picket 11, thereby deforming the protrusions 147 and creating a friction fit.

On occasion, it may be necessary to remove a fence post extension 140 from a star picket 11. This can be done using the handle of a conventional screwdriver as illustrated in Fig. 30. A shoulder of the handle is engaged with the lowermost end of the fence post extension 140. A hammer, or other object, is then used to tap the end of the handle upwardly and thereby drive the fence post extension 140 upwardly. This disengages the fence post extension 140 from the star picket 11. Turning now to Figs. 31 - 37, another hollow fence post extension 240 of a further embodiment of the present invention is illustrated. The fence post extension 240 has an open mouth 244 which extends along the entire length of the extension. In addition, the fence post extension 240 has a hollow cavity or slot 245 which also extends along the entire length of the extrusion. That is, although the extension 240 is hollow, it does not have any enclosed cavity. As a consequence, the extension 240 is able to be extruded as illustrated in Fig. 36 and cut to length as illustrated in Fig. 37. During the cutting process, a portion of the stem 212 is docked and the transverse apertures are punched. The extension 240 is preferably extruded from either plastics material or aluminium. In addition, the slot 245 is preferably provided with a plurality of inwardly projecting longitudinally extending fins or ribs 247.

As before, it will be seen that the truncated star picket 11 A of Figs. 31 and 34 is slightly smaller than the star picket 11B of Figs. 32 and 35. Whilst the shape of the slot 245 closely follows the profile of the star picket 1 IB, the profile of the star picket 11 A is slightly different. However, the presence of the open mouth 244 enables the fence post extension 240 to flex and accommodate the shape of the star picket. In addition, protrusions in the form of the ribs 247 are able to be deformed by coming into contact with the star pickets and thus ensuring a good frictional fit between the fence extension 240 and the star picket, notwithstanding variations in its shape and dimensions.

Turning now to Figs. 38-42, a fence post extension 340 of another embodiment is illustrated. This is formed from a short piece of conventional steel star picket 341 which is connected to a rolled sheet steel bracket 342 by a pair of rivets 343. As best seen in Figs. 41 and 42, the bracket 342 forms a slot 345 having an open mouth 344. If desired, the bracket 342 can be connected to the steel star picket 341 by means of welding, such as spot welding. A further variation of this embodiment is illustrated in Figs 55-58.

As illustrated in Figs. 43 - 46, a fence post extension 540 of yet another embodiment fabricated from extruded irrigation pipe such as high density polyethylene pipe, is illustrated. The pipe is extruded and cut to length. During the cutting operation an upper slot 516 is created to receive the top wire of the modified fence. In a separate stamping operation, an open mouth 544 is formed which is able to receive the stem 12 of the star picket 11. As illustrated in Fig. 45, the internal diameter of the fence post extension 540 is arranged to form a friction fit with the extremities of the arms 13, 14 of the star picket 11. Preferably, holes 521, 523, etc are also drilled in the fence post extension 540.

Since the fence 10 as illustrated in Fig. 1 only contains few wooden posts 20 relative to the many star pickets 11, it is possible for the additional wires as illustrated in Figs. 6 and 52 to be supported only by fence post extensions 40, 140, 240, 340, 540 located above a star picket. In this arrangement, the additional wires above a wooden post 20 would hang slightly lower than above a star picket 11. In practice this does not make any significant difference.

However, as illustrated in Fig. 47, it is also possible to connect a fence post extension 40, 140 for example, to each of the wooden posts 20 by means of a pair of tech screws 50, for example. The tech screws 50 pass through the open mouth 44 and through the back of the slot 45. The arms 113, 114 bear against the wooden post 20.

An alternative arrangement to that illustrated in Fig. 47 is illustrated in Figs. 48 - 51.

A wooden post 120 is provided with a fence post extension in the form of a short length of conventional star picket 11. This is held in place by means of a generally V- shaped connector plate 55. The connector plate 55 is provided with a first series of apertures 56 through which tech screws 50 can pass in order to secure the plate 55 to the post 120. In addition, the plate 55 has a second series of apertures 57 which are able to be aligned with the holes 58 in the star picket 11. When so aligned, a holding mechanism in the form of a pin or tie wire 59 is used to secure the star picket 11 to the plate 55. As best seen in Fig. 49, the star picket 11 is a snug fit within the aperture formed by the wooden post 120 and the plate 55.

As seen in Fig. 52, at each end of a run of fence (possibly provided with mesh 114 or netting 416) there is normally a heavy wooden strainer post 420 complete with a stay. Against the strainer post 420 can be positioned an approximately 2 m high metal star picket 411 as used in exclusion fencing. The star picket 411 can be driven in adjacent to, and abutting, the strainer post 420. Preferably the star picket 411 and the strainer post 420 are secured together by means of a tensioned wire loop 421. This tall star picket 411 then becomes available for use as a strainer post for the high wires 412, 413, and 414 which pass through the fence post extensions 40, 140.

Turning now to Figs. 53 and 54, it sometimes happens that a fence is to be extended in height in order to prevent feral cats, dingoes or foxes for example, from passing over the fence. Under these circumstances it is desirable to outwardly curve the upper portions of the fence so that the animal climbing is obliged to climb in an upside down position and thereby falls off the extended fence. In order to meet this requirement, curved fence post extensions 740 and 840 can be fabricated by heating the fence post extension 40 and bending same whilst in a warm condition, for example by bending it around a large diameter tube (not illustrated). It will be apparent from Figs. 53 and 54 that the fence post extension can be bent in either direction. Whether the fence post extension 740, or the fence post extension 840, is selected for a particular fence, will depend upon the orientation of the star pickets 11 of that fence.

Furthermore, irrespective of the nature of the animals to be excluded by the heightened fence, it is possible to suspend rabbit netting, or similar lightweight meshes, from the elevated wires such as 412, 413, 414, etc. supported by the fence post extensions. In general the amount of steel used in such lightweight meshes will be much less than the amount of steel used in a conventional exclusion fence.

A modification to the arrangement illustrated in Figs. 38-42 is illustrated in Figs. 55- 58. In the former drawings, a short piece of conventional star picket 341 was permanently connected to a rolled steel bracket 342 in order to form a fence post extension 340. In the arrangement illustrated in Figs. 55-58, the rolled steel bracket 1342 is supplied to the farmer who then adds the short piece of conventional steel star picket 341. That is, the rolled steel bracket 1342 is a joiner, rather than an extender. Preferably two screws 1345 are positioned extending through the wings 1113, 1114 so as to provide a stop mechanism which correctly positions the joiner bracket 1342 relative to the star picket 11.

The manufacturing technique of rolling sheet steel utilised to form the rolled steel bracket 1342, can also be utilised to form an entire extender as illustrated in Figs. 59- 63. As seen in Fig. 59, a blank 1400 is fabricated from galvanised sheet steel and provided with various punched apertures 1401 and a cutaway notch 1402. Thereafter, the blank 1400 can be rolled so as to form a rolled steel fence extender 1500 as illustrated in Figs. 61-63 and having a transverse cross-sectional shape as illustrated in Fig. 60. The fence extender 1500 has a stem 1512 which does not extend for the entire length of the fence extender 1500 and is preferably provided with an upper slot 1516 and a plurality of spaced apart transverse apertures 1521, 1523, 1525, 1528, etc.

In addition, in common with the embodiment illustrated in Figs 31-35, the fence extender 1500 has an open mouth 1544 which extends along the entire length of the fence extender 1500. The open mouth 1544 leads into a hollow cavity 1545 which has a generally V-shaped interior and which, as illustrated in Figs. 61-63, is capable of engaging with a conventional star picket 11.

Since the stem 1512 lies to one side of the stem 12 of the star picket 11, two screws 1345 are used to provide a stop mechanism which holds the fence extender 1500 in the desired installed position as illustrated in Figs. 61-63. Advantages of the fence extender 1500 include its strength, low weight and ease of manufacture.

The foregoing describes only some embodiments of the present invention and modifications, obvious to those skilled in the fencing arts, can be made thereto without departing from the scope of the present invention. For example, where it is desired to provide additional wires above a conventional gate (not illustrated) it is possible to connect a fence post extension such as 540 to the frame of the gate by means of U-bolts or similar fasteners.

Still further, it is possible to truncate the length of the fence post extensions 40, 140, etc. so as to produce a short length of plastic which is engageable in an easy way with a conventional star picket fence. Such a short length of plastic if coloured white, for example, can be used as a sighting object for horses. Similarly, such a short length of plastic if coloured yellow or orange, for example, can be used as a warning device for humans on construction sites, for example to prevent accidental injury caused by the sharp upper ends of conventional metal star pickets. Still further, the fence post extensions 40, 140, etc. can also be used as extensions for (sometimes short) metal star pickets so as to display signs by, for example, real estate agents.

The term“comprising” (and its grammatical variations) as used herein is used in the inclusive sense of“including” or“having” and not in the exclusive sense of “consisting only of’.

Claims (34)

1. An elongate fence post, or an elongate fence post extender, having an upper end and a lower end with a hollow interior extending between said ends, said upper end being adapted to be connected with a fence wire, and said hollow interior being of an at least partially Y-shaped configuration.

2. The elongate fence post, or elongate fence post extender, as claimed in claim 1 and having an exterior surface which is substantially Y-shaped.

3. The elongate fence post extender as claimed in claim 2 and for extending the height of a star picket fence post having a substantially Y-shaped cross sectional shape formed by a stem and a pair of arms having a substantially V- shaped configuration, said elongate fence post extender having said lower end which is provided with a longitudinally extending open mouth slot dimensioned to pass over said star picket arms with said open mouth receiving a portion of said stem adjacent said arms.

4. The elongate fence post extender as claimed in claim 3 wherein said open mouth slot does not extend into said upper end.

5. The elongate fence post extender as claimed in claim 4 wherein said open mouth slot has a substantially V-shaped configuration.

6. The elongate fence post extender as claimed in any one of claims 3-5 wherein said upper end has at least one transverse aperture shaped to receive a fencing wire or a tie wire for a fencing wire.

7. A fence post extension for extending the height of a star picket fence post having a substantially Y-shaped cross sectional shape formed by a stem and a pair of arms having a substantially V-shaped configuration, said fence post extension comprising an elongate member having two ends, one of said ends being adapted to be connected with a fence wire and the other of said ends having a longitudinally extending open mouth slot dimensioned to pass over said star picket arms with said open mouth receiving a portion of said stem adjacent said arms.

8. The extension as claimed in claim 7 wherein said open mouth slot does not extend into said one end.

9. The extension as claimed in claim 8 wherein said open mouth slot has a

substantially V-shaped configuration.

10. The extension as claimed in any one of claims 7-9 wherein said one end is substantially solid.

11. The extension as claimed in claim 10 wherein said one end has a generally Y- shaped configuration with a stem and a pair of arms.

12. The extension as claimed in claim 11 wherein the stem of said one end has one or more apertures shaped to receive fencing wire.

13. The extension as claimed in claim 7 wherein said open mouth slot extends between said ends.

14. The extension as claimed in claim 7 wherein said open mouth slot extends the length of said extension.

15. The extension as claimed in claim 13 or 14 wherein said one end is hollow.

16. The extension as claimed in claim 15 wherein said one end does not have any enclosed cavity.

17. The extension as claimed in any one of claims 13-16 wherein said one end has a substantially Y-shaped configuration with a stem and a pair of arms.

18. The extension as claimed in claim 17 wherein the stem of said one end has one or more apertures shaped to receive fencing wire.

19. The extension as claimed in claim 15 or 16 wherein said extension is

substantially a hollow cylinder.

20. The extension as claimed in any one of claims 7-19 wherein said open mouth slot is formed by a rolled sheet metal bracket connected to said one end.

21. The extension as claimed in any one of claims 7-20 and fabricated from a material selected from the class consisting of steel, aluminium and plastics.

22. The extension as claimed in claim 21 and fabricated by extruding or moulding.

23. The extension as claimed in any one of claims 7-22 and truncated.

24. A fence post for an agricultural fence, said fence post having a conventional Y-shaped configuration, being fabricated from plastics material, and having a hollow interior.

25. The fence post as claimed in claim 24 wherein said hollow interior is also

substantially Y-shaped.

26. The fence post as claimed in claim 25 and having a substantially constant wall thickness.

27. The fence post as claimed in any one of claims 24-26 and having a pointed lower end.

28. The fence post as claimed in claim 27 wherein said pointed lower end is

formed by cutting the fence post at an angle to its longitudinal axis.

29. The fence post as claimed in claim 27 wherein said pointed lower end is formed by a separate component joined to said fence post.

30. The fence post as claimed in claim 29 wherein said separate component is moulded and has a tip at one end and a stem at the other end, said stem being engageable with the hollow interior of said fence post.

31. The fence post as claimed in any one of claims 24-30 and having a plurality of apertures extending transversely therethrough.

32. A fence formed from one or more of the fence posts or fence post extensions as claimed in any one of claims 1-31.

33. A method of fabricating an elongate fence post, or an elongate fence post extender, said method comprising the step of extruding a hollow substantially Y-shaped fence post or fence post extender.

34. A method of attaching a fence post extension to a star picket fence post having a substantially Y-shaped cross-sectional shape formed by a stem and a pair of arms having a substantially V-shaped configuration, said method comprising the step of sliding an open mouth slot of said fence post extension over said star picket arms and engaging said open mouth with a portion of said stem adjacent said arms.