An Electric Fence Insulator

Abstract

Electric fencing networks typically include insulators positioned between the fence wire and end posts, to which the wire is to be anchored, in order to avoid short circuiting of the wire through the post. Known insulators can be susceptible to electrical breakdown, reducing the effectiveness of the insulator. An insulator for use in an electric fence is described herein. The insulator includes a body which is manufactured as a unitary part having a first end and a second end. The body includes a first wire attachment portion located at the first end of the body, configured to support a first loop of wire; and a second wire attachment portion located at the second end of the body, configured to support a second loop of wire. The body includes an open framework portion between the first wire attachment portion and the second wire attachment portion.

Description

STATEMENT OF CORRESPONDING APPLICATIONSThe This application is based on the provisional specification filed in relation to New Zealand Patent Application No. 736690, the entire contents of which are incorporated herein by reference.TECHNICAL FIELDThe present invention relates to an insulator for an electric fence, more particularly an insulator for connection between two lengths of wire.BACKGROUNDElectric fencing is known for use in a number of industries, where a current is applied to a fence line to provide an electric shock to any objects that come in contact with it. In agricultural settings, it is widely used for controlling movement of livestock.Typically, electric fencing is provided by a plurality of posts along a fence line with fencing wire, or another filamentous fencing material, supported by the posts to create a barrier. The fencing wire is also conductively connected to energisers which provide the electrical current passing through the wire.Such fences may extend in networks in the order of kilometers in length - requiring a substantial amount of labour (and therefore cost) to install and maintain. As a result, there are a wide range of products, such as connectors and brackets, available to allow the user to securely, safely, and quickly attach fencing wire and other accessories such as energisers to posts, fencing standards or any other object to which the fencing wire is to be secured. While some degradation over time is to be expected given the exposure to the elements and subjugation to high voltage, such products need to be robust in order to reliably function for long periods of time without replacement.For example, insulators are typically positioned between the wire and the end post, to which the wire is to be anchored, in order to avoid short circuiting of the wire through the post. This necessitates connection of the fence wire to the insulator, and a further connection (often another length of wire) between the insulator and the end post.One common insulator design results in loops of the wires overlapping while being separated by insulating material of the insulator. One potential issue with this arrangement is the distance between the point of connection to one wire and that of the other needs to be sufficient to avoid the likelihood of electrical breakdown (i.e. tracking) occurring to produce a conductive pathway between the wires. The resulting size - particularly thickness - of the insulator introduces a higher likelihood of voids being produced during manufacture.The failure load of 2.5mm high tensile fencing wire can be in excess of 600 kilogram-force (kgf). However, in practice there are little controls on how much tension a fence installer applies to the wire, so there is a possibility the insulator may be subjected to higher loads from time to time. Under this level of tension, the presence of voids may promote the formation of stress cracks.As well as being generally undesirable for the purposes of structural integrity, such stress cracks can also compromise electrical insulation by producing tracking paths between the wires. Further, the proximity of voids to the high voltage of the electric fence can result in a partial discharge beginning within the void. The surrounding insulator material can be eroded as a result, eventually forming a tracking path through the insulating material.It is an object of the present invention to address one or more of the foregoing problems or at least to provide the public with a useful choice.All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.Throughout this specification, the word "comprise", or variations thereof such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.According to one aspect of the present disclosure there is provided an insulator for use in an electric fence. It is envisaged that exemplary embodiments of the insulator may be configured for use in a high tensile fence, in which fencing wire secured to the insulator may have a breaking strength of approximately 600 kilogram-force (kgf). In such embodiments, it is envisaged that the insulator may be configured to resist forces greater than the breaking strength of the wire, for example at least 1 and a half times the breaking strength of the wire, for example substantially twice the breaking strength of the wire.According to one aspect of the present disclosure there is provided an insulator for use in an electric fence, including:a body having a first end and a second end, including:a first wire attachment portion located at the first end of the body, configured to support a first loop of wire;a second wire attachment portion located at the second end of the body, configured to support a second loop of wire;an open framework portion between the first wire attachment portion and the second wire attachment portion.While reference will be made throughout the specification to the insulator being for use with wire in an electric fence, it should be appreciated that this is not intended to limit use to single solid core lengths of metal, but encompasses other filamentous barrier members known in the art - such as stranded or braided wire, or fibrous rope-like material woven with fine conducting wires (known as 'poly-wire' in the field of electric fencing).To assist with understanding of the present disclosure, the body may be described herein as having a longitudinal axis between the first end and the second end. A tensile axis may also be described, extending between the first wire attachment portion and the second wire attachment portion, and being the axis along which tensile loads are predominantly applied to the body. In use, as the first and second wires are tensioned, stress is concentrated at the points of connection to the body (i.e. the first wire attachment portion and the second wire attachment portion). It is envisaged that the tensile axis may be collinear with the longitudinal axis, although it should be appreciated that embodiments are contemplated in which the tensile axis and the longitudinal axis are not collinear.The basic function of an insulator in an electric fence system is to prevent short circuiting of the wires. As such, insulators need to have sufficient creepage distance between the points of connection to the first wire attachment portion and the second wire attachment portion to prevent arcing. However, this should be balanced with keeping the overall size of the insulator compact, whether this be for ergonomic factors, cost of materials, or speed of manufacture.In an exemplary embodiment, it is envisaged that the creepage distance along the surface of the body of the insulator between wire bearing surfaces of the first wire attachment portion and the second wire attachment portion may be at least 32 mm. In an exemplary embodiment, the creepage distance may be at least 60 mm. In an exemplary embodiment, the creepage distance may be at least 90 mm. In doing so, it is envisaged that the likelihood of tracking between the first and second wires may be reduced.It should be appreciated that the minimum creepage distance and clearance distance may be dependent on the material type used for manufacture, the type of fence, the output of the energiser the insulator is intended for use with. By way of example, in a long highly conductive fence wire, higher voltages than those that occur at the output of an energiser may result from resonance effects of a fence line. Sometimes up to double the voltage of the energiser output can occur at various location along the fence where insulators are positioned. In the case of an 8 KV pulse output, this may result in a peak of 16 KV. Approximating the surface tracking of plastic materials at about 0.5 KV / mm results in the minimum 32 mm creepage distance being required. However, it is envisaged that exemplary embodiments of the body of the present disclosure may enable a tracking distance of about 95mm or greater to be achieved in a relatively compact form having a clearance distance of about 60 mm. Means by which these distances may be achieved is described further below.In exemplary embodiments, the insulator may be made of any electrically insulating material deemed to be suitable by a person skilled in the art. For example, the insulating material may be a plastics material. By way of example, the inventors envisage that the insulator may be made of polycarbonate, nylon, or polybutylene terephthalate (PBT) - being electrically insulating while having material properties suitable for use in fencing applications in terms of toughness. It should be appreciated that this is not intended to be limiting, and other exemplary materials may include polyester, polypropylene, high density polyethylene (HDPE), or acrylonitrile butadiene styrene (ABS), and fibre-reinforced variants of these materials.In an exemplary embodiment, the body - including the first wire attachment portion, the second wire attachment portion, and the open framework portion - may be manufactured as a unitary part. It is envisaged that the insulator as a whole may be manufactured as a unitary part. For example, the body may be manufactured in a single mould, machined as a single piece, or produced as a single part by an additive manufacturing process. However, it should be appreciated that in exemplary embodiments one or more of the features of the insulator may be manufactured as a separate part and attached to the remaining features by any suitable means known in the art.Reference to an open framework should be understood to mean a structure made of a number of structural members such as beams, strips, bars, girders, or the like, which are contacting, crossing or overlapping in a regular or irregular pattern to produce at least one framework aperture. It is envisaged that the open framework may include longitudinal structural members extending between the first wire attachment portion and the second wire attachment portion, and transverse structural members across at least one of the longitudinal structural members. The structural members may have a straight shape, but may also have a curved shape. Such a structure may be understood as being lattice-like, although it should be understood that unless expressly stated in relation to an exemplary embodiment this is not intended to require a particular geometric shape of the framework aperture(s), nor regularity of those apertures.It is envisaged that the open framework may assist in the shedding of water, allowing water to drain through the framework apertures rather than pooling, while assisting in achieving a necessary strength in tension for use in high tension fences. Pooling of water might otherwise compromise the electrically insulating properties of the insulator. While it should be appreciated that the dimensions of the framework apertures required to prevent the retention of water droplets will be at least partially dependent on the type of material and surface finish, it is envisaged by the inventors that the frame work apertures may have a minimum diameter of 6 mm to reduce the likelihood of water droplet retention.In an exemplary embodiment of the present application, the longitudinal structural members of the open frame work may collectively have a cross sectional area of at least 200 mm at right angles to the tensile axis. In an exemplary embodiment, the cross sectional area may be in the range of about 220 mm to about 250 mm. In an exemplary embodiment, the cross sectional area may be in the range of about 225 mm to about 235 mm. It should be appreciated that this is not intended to be limiting to all embodiments of the present disclosure, as this characteristic may be determined by selected materials for manufacture and tensile strength requirements of a particular embodiment.In an exemplary embodiment, the open framework may include two or more longitudinal structural members extending between the first wire attachment portion and the second wire attachment portion. In an exemplary embodiment, the open frame work may include two outer longitudinal structural members, and at least one inner longitudinal structural member. In an exemplary embodiment, the open framework may include two outer longitudinal structural members, and at least two inner longitudinal structural members.In an exemplary embodiment, the open framework may include at least one shield in an orientation transverse to the longitudinal structural members. Reference to a shield should be understood to mean a flange-like structure, broader in a radial direction than its thickness along the longitudinal axis. It is known to include protrusions on the surface of an insulator dedicated to increasing the creepage distance (also known in the art of electric fencing as tracking fins, creepage flanges, or flashguards). It is envisaged that the at least one shield may assist in increasing creepage distance over the surface of the body to reduce the likelihood of electrical breakdown (i.e. tracking) occurring and leading to short-circuiting between the first and second wires.In an exemplary embodiment, the at least one shield may intersect each of the longitudinal structural members.In an exemplary embodiment, the at least one shield may extend radially beyond the at least one inner longitudinal structural member. In doing so, tracking along the inner longitudinal structural member is required to pass over the at least one shield in order to ensure that a minimum tracking distance is achieved.In an exemplary embodiment, each wire attachment portion may include a wire bearing member about which a wire may be looped around back onto itself.In an exemplary embodiment, each wire attachment portion may include opposing arms with a space therebetween, having a bridging portion therebetween. In an exemplary embodiment, the open framework portion of the insulator may connect to the bridging portions of the respective wire attachment portions.In an exemplary embodiment, each wire attachment portion may include the wire bearing member between the opposing arms, having a wire aperture between the wire bearing member and the bridging portion through which a wire may be passed. Orientation of a wire attachment portions may herein be described with reference to an axis through the wire bearing member - a "bearing axis".In an exemplary embodiment, the first wire attachment portion may be oriented relative to the second wire attachment portion such that the bearing axes are substantially parallel. It is envisaged that in exemplary embodiments, the greatest width of the wire attachment portion (i.e. the distance between the outwardly facing surfaces of the opposing arms) may be less than the greatest height of the wire attachment portion (for example, the distance between upper and lower edges of the bridging portion).By aligning the orientation of the first wire attachment portion with that of the second wire attachment portion, it is envisaged that one or more effects may be achieved. For example, it is envisaged that this may assist in a providing a more consistent peripheral shape for ergonomic factors such as gripping of the insulator in the hand. As another example, the wire apertures may both be in the same orientation for consistency in draining water. As another example, less material may be used to manufacture the insulator in comparison with an embodiment in which the bearing axes are perpendicular, would require additional features or size to achieve the same creepage paths.In an exemplary embodiment, the orientation of the at least one framework aperture of the open frame work wire may be aligned with the orientation of the wire apertures. For example, where the insulator is configured for use such that the wire apertures are vertical relative to ground, the at least one framework aperture may also be vertically oriented, such that water is drawn by gravity to pass through the apertures and fall to the ground.In an exemplary embodiment, each wire attachment portion may include a lateral wing extending from each side of the wire attachment portion, increasing the creepage distance. It is envisaged that in exemplary embodiments the lateral wings may be generally oriented in a similar manner to the at least one shield.In exemplary embodiments, the insulator may include one or more reinforcing ribs. In an exemplary embodiment, the reinforcing ribs may extend along the outside surfaces of the arms of the wire attachment portions. It is envisaged that this may assist in increasing the strength of the arms to resist deflection when wire tension is applied. In an exemplary embodiment, the one or more reinforcing ribs may extend along the longitudinal axis from the end of the body to the lateral wings.According to an exemplary embodiment there is provided an electric fence system. The electric fence system may include at least one fence post. The electric fence system may include at least one insulator substantially as herein described, to be secured to the fence post by a first wire looping about a first wire attachment portion of the insulator. The electric fence system may include a second fence wire secured to the insulator by looping said second wire about the second wire attachment portion of the insulator.According to an exemplary embodiment there is provided a method of installing an electric fence system. The method may include the step of securing at least one insulator, substantially as herein described, to a first wire by looping said first wire about the first wire attachment portion of the insulator. The method may include the step of securing the insulator to a second wire by looping said second wire about the second wire attachment portion of the insulator.BRIEF DESCRIPTION OF THE DRAWINGSFurther aspects of the present invention will become apparent from the ensuing description which is given by way of example only and with reference to the accompanying drawings in which:FIG. 1 is a perspective view of an exemplary insulator according to an aspect of the present disclosure; FIG. 2 is a top view of the exemplary insulator; FIG. 3 is a side view of the exemplary insulator; FIG. 4 is an end view of the exemplary insulator; FIG. 5 is a cross-sectional view of a portion of the exemplary insulator; FIG. 6-1 is a side view of a second exemplary insulator according to an aspect of the present disclosure; FIG. 6-2 is a top view of the second exemplary insulator; FIG. 7-1 is a side view of a third exemplary insulator according to an aspect of the present disclosure; FIG. 7-2 is a top view of the third exemplary insulator; FIG. 8-1 is a side view of a fourth exemplary insulator according to an aspect of the present disclosure; FIG. 8-2 is a top view of the fourth exemplary insulator; and FIG. 9 is a top view of a fifth exemplary insulator according to an aspect of the present disclosure. DETAILED DESCRIPTION FIG. 1 to FIG. 4 illustrate an exemplary insulator 100 for use in an electric fence according to one aspect of the disclosure. The insulator 100 includes a body having a first wire attachment portion 102-1 at a first end, a second wire attachment portion 102-2 at a second end distal from the first end, and an open framework portion 104 between the first wire attachment portion 102-1 and the second wire attachment portion 102-2.In an exemplary embodiment, the insulator is made of an electrically insulating material such as polycarbonate, nylon, or polybutylene terephthalate (PBT). It should be appreciated that this is not intended to be limiting to all embodiments of the present disclosure, and other exemplary materials may include polyester, polypropylene, high density polyethylene (HDPE), or acrylonitrile butadiene styrene (ABS), and fibre-reinforced variants of these materials.In the exemplary embodiment illustrated, the body of the insulator 100 - including the first wire attachment portion 102-1, the second wire attachment portion 102-2, and the open framework portion 104 - is manufactured as a unitary part. It is envisaged that the insulator 100 may be manufactured by moulding, although it should be appreciated that other manufacturing techniques may be utilized by those skilled in the art.Each of the first wire attachment portion 102-1 and the second wire attachment portion 102-2 includes a first arm 106 and a second arm 108 in a spaced apart relationship, having a bridging portion 110 therebetween at an end of the arms 106, 108 proximate to the open framework portion 104 to provide a generally "U" shaped structure.Each of the first wire attachment portion 102-1 and the second wire attachment portion 102-2 includes a wire bearing member 112 between the opposing arms 106,108, having a wire aperture 114 (not clearly seen in FIG. 1, but see FIG. 2) between the wire bearing member 112 and the bridging portion 110. In use, a wire may be passed through the wire aperture 114, and looped around back onto itself around the wire bearing member, before being secured to maintain the loop (for example by tying off the wire on itself, or crimping the wire to itself). As the wire(s) are tensioned, the wire loop bears primarily against the wire bearing member 112 on the surface facing the bridging portion 110.To assist with understanding of the present disclosure, various elements of the insulator may be described in terms of having a height, or width, or length. It should be appreciated that such terms are relative, and not intended to limit the insulator to use in a particular orientation. For example, the insulator 100 may be described herein as having a longitudinal axis between the first end and the second end, i.e. along its length. Width may be understood as the dimension of an element in a direction perpendicular to the longitudinal axis and parallel with a transverse axis along the wire bearing member 112 between the opposing arms 106, 108. Height may be understood as the dimension of an element in a direction perpendicular to the transverse axis.Each of the first wire attachment portion 102-1 and the second wire attachment portion 102-2 includes a first lateral wing 116 and a second lateral wing 118 extending outwardly from the first arm 106 and the second arm 108 respectively. The lateral wings 116, 118 increase the creepage distance along the surface of the insulator 100 between the wire bearing members 112.In the exemplary embodiment illustrated, each of the first wire attachment portion 102-1 and the second wire attachment portion 102-2 includes a first upper reinforcing rib 120 and a first lower reinforcing rib 122 on the outer surface of the first arm 106, extending between the first lateral wing 116 and the ends of the insulator 100. The first wire attachment portion 102-1 and the second wire attachment portion 102-2 also include a second upper reinforcing rib 124 and a second lower reinforcing rib 126 on the outer surface of the second arm 108, extending between the second lateral wing 118 and the ends of the insulator 100. It is envisaged that these reinforcing ribs may assist in increasing the strength of the arms 106, 108 to resist deflection when wire tension is applied.The open framework portion 104 of the insulator 100 includes a first inner longitudinal structural member 128 and a second inner longitudinal structural member 130. The inner longitudinal structural members 128 and 130 are positioned side by side in a spaced relationship, extending between the bridging portions 110-1 and 110-2 of the first wire attachment portion 102-1 and the second wire attachment portion 102-2.The open framework portion 104 also includes a first outer longitudinal structural member 132 and a second outer longitudinal structural member 134. The first outer longitudinal structural member 132 and the second outer longitudinal structural member 134 are positioned on the outside of the inner longitudinal structural members 128 and 130. The first outer longitudinal structural member 132 and the second outer longitudinal structural member 134 extend between the first lateral wings 116-1 and 116-2, and the second lateral wings 118-1 and 118-2, respectively.As more clearly seen in FIG. 3, the height of the inner longitudinal structural members 128 and 130 is greater than the outer longitudinal structural members 132 and 134. Further, the upper and lower edges of the outer longitudinal structural members 132 and 134 are substantially aligned with the upper and lower reinforcing ribs (ribs 120 and 122, and ribs 124 and 126 respectively). The upper and lower edges of the outer longitudinal structural members 132 and 134 are reinforced, to effectively extend the reinforcing of the ribs the length of the insulator 100.In the exemplary embodiment illustrated, the open framework portion 104 also includes a first shield 136 and a second shield 138. The shields 136 and 138 are generally disk-shaped, and are spaced apart along the longitudinal axis of the insulator 100 between the bridging portions 110-1 and 110-2. The shields 136 and 138 intersect the inner longitudinal structural members 128 and 130, and extend to the outer longitudinal structural members 132 and 134. The shields 136 and 138 project above and below the inner longitudinal structural members 128 and 130. In doing so, the tracking distance along the inner longitudinal structural members passes over the shields 136 and 138 in order to ensure that a minimum tracking distance is achieved.In this exemplary embodiment, the shields 136 and 138 extend to, but not beyond, the outer longitudinal structural members 132 and 134. Also, the height of the shields 136 and 138 is such that the upper and lower edges of the shields 136 and 138 are substantially level with the upper and lower edges of the bridging portions 110-1 and 110-2 proximate the open framework portion 104. These features are envisaged as maintaining a contained overall shape to assist with the ergonomic factors of the insulator, more particular a user's comfort and grip when holding the insulator in a hand.It is also envisaged that orienting the first wire attachment portion 102-1 and the second wire attachment portion 102-2 such that the respective wire apertures 114 are substantially parallel may assist with achieving a profile in which the height of the insulator 100 is greater than its width - as may be seen in FIG. 4 - which is considered to have a desirable ergonomic form for grasping with a hand.With reference to FIG. 3, each of the first wire attachment portion 102-1 and the second wire attachment portion 102-2 includes a recessed portion 140 on the outer surfaces of the second arms 108, with corresponding recessed portions on the outer surfaces of the first arms 106 (not shown in FIG. 3). These recesses are aligned with the wire bearing members 112, to reduce the wall thickness of the wire bearing members 112. In exemplary embodiments in which the insulator 100 is moulded, it is envisaged that this may assist with at least one of: reducing the likelihood of voids in the wire bearing members 112, achieving desirable flow conditions through the mould, reducing cooling time, use of materials having desirable insulating and strength properties.The outward facing surfaces of the outer longitudinal structural members 132 and 134 have beveled recesses (for example beveled recess 142 of the second outer longitudinal structural member 134, as shown in FIG. 3). Referring to FIG. 5, the beveled recess 142 has a vertical surface 144, overhanging surface 146, and lower sloping surface 148. The obtuse angle 150 between the vertical surface 144 and the overhanging surface 146, and the vertical surface 144 lower sloping surface 148, may be in the order of 135°. It is envisaged that this may assist with shedding water from the beveled recess 142, even when the insulator 100 is installed at an angle, to prevent pooling and compromise to the insulating properties of the insulator 100 as a whole.FIG. 6-1 and FIG. 6-2 illustrate another exemplary insulator 600, generally configured in a manner similar to insulator 100 described above. The insulator 600 includes an open framework including upper and lower vertically oriented longitudinal structural members 602-1 and 602-2 extending between first and second bridging portions 604-1 and 604-2. The open framework also includes first and second horizontally oriented longitudinal structural members 606-1 and 606-2 extending between, and across the first and second bridging portions 604-1 and 604-2, and first lateral wings 608-1 and 610-1 and second lateral wings 608-2 and 610-2. First and second shields 612-1 and 612-2 are spaced apart along the longitudinal axis of the insulator 600 between the bridging portions 604-1 and 604-2, intersecting and extending outwardly beyond the longitudinal structural members 602-1, 602-2, 606-1 and 606-2.FIG. 7-1 and FIG. 7-2 illustrate another exemplary insulator 700, generally configured in a manner similar to insulator 100 described above. The insulator 700 includes an open framework including upper and lower vertically oriented longitudinal structural members 702-1 and 702-2 extending between first and second bridging portions 704-1 and 704-2. The open framework also includes a horizontally oriented longitudinal structural member 706 extending between, and across the first and second bridging portions 704-1 and 704-2, and first lateral wings 708-1 and 710-1 and second lateral wings 708-2 and 710-2. First and second shields 712-1 and 712-2 are spaced apart along the longitudinal axis of the insulator 700 between the bridging portions 704-1 and 704-2, intersecting and extending outwardly beyond the longitudinal structural members 702-1, 702-2, and 706-1. The insulator 700 also includes first secondary lateral wings 714-1 and 716-1, and second secondary lateral wings 714-2 and 716-2, offset from the first lateral wings 708-1 and 710-1 and second lateral wings 708-2 and 710-2 along the longitudinal axis towards their respective ends.FIG. 8-1 and FIG. 8-2 illustrate another exemplary insulator 800, generally configured in a manner similar to insulator 100 described above. The insulator 800 includes an open framework including horizontally oriented longitudinal structural members 802-1, 802-2, 802-3, 802-4, 802-5, 802-6 extending between first and second bridging portions 804-1 and 804-2, and across first lateral wings 806-1 and 808-1 and second lateral wings 806-2 and 808-2 to varying extents. First and second shields 810-1 and 810-2 are spaced apart along the longitudinal axis of the insulator 800 between the bridging portions 804-1 and 804-2, intersecting and extending outwardly beyond the longitudinal structural members 802-1 to 802-6.FIG. 9 illustrates another exemplary insulator 900. The insulator 900 includes a body having a first wire attachment portion 902-1 at a first end, a second wire attachment portion 902-2 at a second end distal from the first end. Each of the first wire attachment portion 902-1 and the second wire attachment portion 902-2 includes a wire aperture 904-1 and 904-2 respectively. In this exemplary embodiment, the first wire attachment portion 902-1 and the second wire attachment portion 902-2 are perpendicularly oriented.Each of the first wire attachment portion 902-1 and the second wire attachment portion 902-2 includes a first primary lateral wing 906 and a first secondary lateral wing 908 set back from the first primary lateral wing 906 extending outwardly from the wire attachment portion 902, and a second primary lateral wing 910 and a second secondary lateral wing 912 extending outwardly from the opposing side of the wire attachment portion 902.An open framework portion 914 extends between the first wire attachment portion 902-1 and the second wire attachment portion 902-2. The open framework 914 includes a first longitudinal structural member 916-1 and a second longitudinal structural member 916-2. In the exemplary embodiment illustrated, the open framework portion 914 also includes a first shield 918-1 and a second shield 918-2 spaced apart along the longitudinal axis of the insulator 900 and intersecting the first and second longitudinal structural member 916-1 and 916-2.The entire disclosures of all applications, patents and publications cited above and below, if any, are herein incorporated by reference.Reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in the field of endeavour in any country in the world.The invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features.Where in the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth.It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be included within the present invention.Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims.

Claims

CLAIMS1.      An insulator for use in an electric fence, including:a body having a first end and a second end, including:a first wire attachment portion located at the first end of the body, configured to support a first loop of wire;a second wire attachment portion located at the second end of the body, configured to support a second loop of wire;an open framework portion between the first wire attachment portion and the second wire attachment portion.

2. The insulator of claim 1, wherein the body is manufactured as a unitary part.

3. The insulator of claim 1 or claim 2, wherein the creepage distance along the surface of the body of the insulator between wire bearing surfaces of the first wire attachment portion and the second wire attachment portion is at least 32 mm.

4. The insulator of claim 3, wherein the creepage distance is at least 60 mm.

5. The insulator of claim 3, wherein the creepage distance is at least 90 mm.

6. The insulator of any one of claims 1 to 5, wherein the open framework portion includes longitudinal structural members extending between the first wire attachment portion and the second wire attachment portion, and transverse structural members across at least one of the longitudinal structural members.

7. The insulator of claim 6, wherein the body has a tensile axis extending between the first wire attachment portion and the second wire attachment portion, and the longitudinal structural members of the open frame work collectively have a cross sectional area of at least 200 mm at right angles to the tensile axis.

8. The insulator of claim 7, wherein the cross sectional area is in the range of about 220 mm to about 250 mm.

9. The insulator of claim 7, wherein the cross sectional area is in the range of about 225 mm to about 235 mm.

10. The insulator of any one of claims 6 to 9, wherein the open framework portion includes two or more longitudinal structural members extending between the first wire attachment portion and the second wire attachment portion.

11. The insulator of claim 10, wherein the open framework portion includes longitudinal structural members, and at least one inner longitudinal structural member.two outer12.    The insulator of claim 10, wherein the open framework portion includes two outer longitudinal structural members, and at least two inner longitudinal structural members.

13. The insulator of any one of claims 6 to 12, wherein the open framework portion includes at least one shield in an orientation transverse to the longitudinal structural members.

14. The insulator of claim 13, wherein the at least one shield intersects each of the longitudinal structural members.

15. The insulator of claim 13 when dependent on claim 11, wherein the at least one shield extends radially beyond the at least one inner longitudinal structural member.

16. The insulator of any one of claims 1 to 15, wherein each wire attachment portion includes a wire bearing member about which a wire may be looped around back onto itself.

17. The insulator of any one of claims 16, wherein each wire attachment portion includes opposing arms with a space therebetween, having a bridging portion therebetween.

18. The insulator of claim 17, wherein the open framework portion of the insulator connects to the bridging portions of the respective wire attachment portions.

19. The insulator of claim 17 or claim 18, wherein each wire attachment portion includes the wire bearing member between the opposing arms, having a wire aperture between the wire bearing member and the bridging portion through which a wire may be passed.

20. The insulator of claim 19, wherein the orientation of at least one framework aperture of the open framework portion is aligned with the orientation of the wire apertures.

21. The insulator of any one of claims 16 to 20, wherein the first wire attachment portion is oriented relative to the second wire attachment portion such that bearing axes of the respective wire bearing members are substantially parallel.

22. The insulator of any one of claims 1 to 21, wherein each wire attachment portion includes a lateral wing extending from each side of the wire attachment portion.

23. The insulator of any one of claims 1 to 22, the insulator includes one or more reinforcing ribs.

24. The insulator of claim 23, the reinforcing ribs extend along the outside surfaces of the arms of the wire attachment portions.

25. The insulator of claim 23 when dependent on claim 22, wherein each of the one or more reinforcing ribs extend along a longitudinal axis of the body from the end of the body to the lateral wings.

26. An electric fence system, including:at least one fence postat least one insulator as claimed in any one of claims 1 to 25, secured to the fence post by a first wire looping about a first wire attachment portion of the insulator, anda second fence wire secured to the insulator by looping said second wire about the second wire attachment portion of the insulator.

27. A method of installing an electric fence system, including:securing at least one insulator, as claimed in anyone of claims Ito 25, to a first wire by looping said first wire about the first wire attachment portion of the insulator; andsecuring the insulator to a second wire by looping said second wire about the second wire attachment portion of the insulator.Fl108-1   124-1   126-1106-2108-1   110-1110-1124-1126-1

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