Electric fence insulator

Abstract

An insulator for an electric fence having at least one wire is described. The insulator includes a body having a first end and a second end, a post connector portion at the first end of the body for connecting the insulator to a fence post, a wire attachment portion at the second end of the body, and at least one shield surrounding and extending outwardly from the body at a position away from the connector portion towards the second end, the shield including lateral portions on either side of the body. The lateral portions of the shield angle away from the second end of the body towards the first end of the body, such that when installed a straight section of the wire cannot bear against respective edges of both lateral portions simultaneously, and pass along their entire lengths, without contacting the fence post.

Claims

1. An insulator for an electric fence having at least one wire, including: a body having a first end and a second end; a post connector portion at the first end of the body, for connecting the insulator to a fence post; a wire attachment portion at the second end of the body; and a plurality of substantially parallel arcuate shields, each of the shields surrounding and extending outwardly from the body at a position away from the post connector portion towards the second end, each of the shields including lateral portions on either side of the body, wherein the lateral portions of each of the shields are angled away from the second end of the body towards the first end of the body, such that when installed a straight section of the wire cannot bear against respective edges of both lateral portions simultaneously, and pass along their entire lengths, without contacting the fence post.

2. An insulator as claimed in claim 1, wherein: the post connector portion includes a post bearing surface facing away from the second end of the body; and the lateral portions of at least one of the shields come within at least a distance less than the diameter of the wire of the electric fence of intersecting a transverse plane located on a longitudinal axis of the body and intersecting a portion of the post bearing surface closest to the second end of the body.

3. An insulator as claimed in claim 2, wherein the transverse plane is substantially perpendicular with the longitudinal axis.

4. An insulator as claimed in claim 2, wherein the transverse plane is substantially perpendicular to the longitudinal axis in only one dimension.

5. An insulator as claimed in claim 2, wherein the lateral portions of at least one of the shields intersect the transverse plane.

6. An insulator as claimed in claim 1, wherein an outer edge of at least one of the shields is curved.

7. An insulator as claimed in claim 6, wherein the outer edge of at least one of the shields is curved towards a lateral plane intersecting the longitudinal axis along its length.

8. An insulator as claimed in claim 1, wherein at least one of the shields is substantially in the shape of a cylindrical paraboloid with rounded corners.

9. An insulator as claimed in claim 1, wherein a radial distance by which each of the shields extends outwardly from the body may be less than that of the next shield closer to the second end.

10. An electric fence system, including: at least one fence post; at least one insulator as claimed in claim 1; at least one fence line, to be supported by the wire attachment portion of the insulator.

11. A method of installing an electric fence system, including the steps of: securing at least one insulator, as claimed in claim 1, to a fence post using the post connector portion of the insulator; and supporting at least wire one wire at the wire attachment portion of the insulator.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further 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:

(2) FIG. 1A is an isometric view of an exemplary insulator;

(3) FIG. 1B is a top view of the exemplary insulator;

(4) FIG. 1C is a side view of the exemplary insulator;

(5) FIG. 1D is a front view of the exemplary insulator;

(6) FIG. 2A is a top view of another exemplary insulator;

(7) FIG. 2B is a side view of the other exemplary insulator;

(8) FIG. 3A is a top view of a further exemplary insulator;

(9) FIG. 3B is a side view of the further exemplary insulator, and

(10) FIG. 4 is a perspective view of a section of an exemplary fence system.

DETAILED DESCRIPTION

(11) FIG. 1A illustrates an insulator 10 for an electric fence. The insulator includes a body 12, having a first end 14 and a second end 16.

(12) A wire attachment portion 18 is located at the second end 16, including a first claw 20a and a second claw 20b, between which a wire may be placed in order to secure it relative to the insulator 10. It should be appreciated that other means for securing the wire could readily be used in place of the wire attachment portion 18.

(13) A post connector portion 22 is located at the first end 14 of the body 12, having two opposing arms 24a and 24b. Fastener apertures 26a and 26b pass through the arms 24a and 24b respectively. Between the arms 24a and 24b, at the same location indicated by arrow 14, is a post bearing surface facing away from the second end 16 of the body 12.

(14) The insulator 10 includes a primary shield 28, located at the second end 16 and surrounding and extending outwardly from the body 12. A secondary shield 30 is located between the first shield 28 and the first end 14. In the illustrated embodiment, the secondary shield 30 has smaller dimensions than the primary shield 28, such that it does not project beyond the primary shield when viewed from the side, or the second end 16as seen in FIGS. 1C and 1D respectively. It should be appreciated that this is not intended to be limiting, and that in embodiments the secondary shield 30 may project beyond the primary shield 28particularly towards the first end 14while still achieving the functionality described in further detail below.

(15) Referring to FIG. 1B, the body 12 includes a longitudinal axis 32, along which the first and second shields 28, 30 are located. The primary shield 28 includes first and second primary lateral portions 34a and 34b on either side of the body 12. The secondary shield 30 is similarly configured, including first and second secondary lateral portions 36a and 36b. Each of the lateral portions 34a, 34b, 36a, 36b angle away from the second end 16 towards the first end 14.

(16) The insulator 10 may be connected to a fencepost 38, by inserting a fastener (for example, a rivet, or bolt 40 or a pin) through the apertures 26a and 26bthe apertures 26a and 26b being more clearly illustrated in FIG. 1Aof the arms 24a and 24b and corresponding apertures (not illustrated) in the post 38. The post 38 bears against the first end 14 of the body 12, and the interior of the arms 24a and 24b collectively provide a post bearing surface to maintain the orientation of the insulator 10 relative to the post 38.

(17) A first transverse plane 42, substantially perpendicular with the longitudinal axis 32, dissects the longitudinal axis 32 and intersects the portion of the post bearing surface closest to the second end 16 of the body 12. The lateral portions 34a, 34b, 36a, 36b of the shields 28 and 30 intersect the first transverse plane 42. In doing so, a straight section of the wire cannot bear against lateral portions 34a, 34b, 36a, 36b on both sides of the longitudinal axis 32 simultaneously, and pass along their entire lengths, without contacting the fence post 38 (as will be described further below with reference to FIG. 1C).

(18) A second transverse plane 44 is shown to demonstrate another configuration the insulator 10 could take. The second transverse plane 44 is longitudinally displaced from the first transverse plane 42 towards the second end 16. In an exemplary embodiment, the lateral portions 34a, 34b, 36a, 36b could be configured to reach the second transverse plane 44, but not extend across the gap between the first and second transverse planes 42, 44where the gap is less than the diameter of the wire to be used in the fence.

(19) FIG. 1C shows the overlap of the primary shield 28 with the post 38 when viewed from the side. The outer edge 46 of the primary shield 28 is curved along its length towards the longitudinal axis 32, such that a wire 48 positioned on the edge 46 will be drawn by its tension and/or by gravity in that direction, and contact the post 38.

(20) Referring to FIG. 1D, the upper and lower portions 46a and 46b of the edge 46 is also curved to assist with this. As the edge of the shield 28 curves in a direction from the wire supporting claws 20a and 20b towards the post (post not illustrated in FIG. 1D, but see post 38 in FIG. 1B) the edge of the shield 28 is also sloped towards a lateral plane through the longitudinal axis 32. This means a wire 48 resting on top of the shield edge 46a will slide down the edge until resting in contact with the post. This will create a short circuit to the post, sensing of which may be registered as an alarm condition by sensing devices well known in the art, and cause an alarm to be raised.

(21) Referring again to FIG. 1A, the secondary shield 30 is similarly shaped. The resulting shape of the primary and secondary shields 28 and 30 is substantially that of a cylindrical paraboloid with rounded cornersproviding a shape which has a long creepage distance across its surfaces, while avoiding creating points on which a wire might be positioned to assist in attempting to breach the fence. It can be seen if a wire was removed from between the claws 20a and 20b, that wire could not be rested or retained between shields 28 and 30 due to the curved shape of the shields and the smaller dimensions of the secondary shield 30 compared to the primary shield 28.

(22) Returning to FIG. 1C, the upwards facing claw 20b includes a structural weakness in the form of notch 50. If an attempt is made to breach the fence by climbing, the claw 20b will fail due to the resulting force applied by the wirewith a high likelihood of the wire subsequently touching the post 38, or an adjacent wire, to trigger an alarm.

(23) The upper surface 52 of the downwards facing claw 20a is sloped downwardly towards the longitudinal axis 32, to avoid presenting a point at which a wire could be held to assist an intrusion attempt.

(24) FIG. 2A and FIG. 2B illustrate another insulator 200 having a body 202 with a post connector portion 204 at a first end, and a wire attachment portion 206 at a second end, with a primary shield 208 and a secondary shield 210 positioned there between. These features of the insulator 200 are generally configured in the manner described with reference to insulator 10 above, with the exception of the shields 208 and 210 not extending back as far as the post connector portion 204.

(25) The insulator 200 includes a plurality of ridges extending between the secondary shield 210 and the post connector portion 204, sloping inwardly from the secondary shield 210: vertical ridges 212a and 212b, and horizontal ridges 214a and 214b. A tensioned wire bearing against the shields 208 or 208 will ride along the edge of the shield onto the ridges 212a, 212b, 214a, 214b, and onwards to the post secured in the post connector portion 204.

(26) FIG. 3A and FIG. 3B illustrate another insulator 300 of a similar configuration to insulator 200replacing the ridges 212a, 212b, 214a, 214b by shaping the body 302 to slope from the secondary shield 304 to the post connector portion 306.

(27) It should be appreciated that while the embodiments illustrated in FIGS. 2A, 2B, 3A, and 3B depict the guide surface as extending to the periphery of the secondary shield, this is not intended to be limiting. In alternative embodiments, the outermost point on the guide surface may be closer to the longitudinal axis of the body than the periphery of the shield.

(28) Also, in exemplary embodiments the guide surface, or at least the inwardly sloping portion towards the post connector portion, may not extend the entire distance from the post connector portion to the shield. Rather, the guide surface may only extend as far as the reach of the shieldi.e. bridging the gap between the point at which the shield ends and the post connector portion. An exemplary embodiment of such an arrangement is illustrated in dashed relief 308 in FIG. 3A.

(29) FIG. 4 illustrates a portion of a fencing system 400, in which first and second insulators 402a and 402b (generally configured in the manner of insulator 10 as previously described) are secured to post 404 in a spaced relationship. A first wire 406a is secured by the first insulator 402a, and a second wire 406b by the second insulator 402b.

(30) The configuration of the insulators 402a and 402b (discussed in greater detail with reference to insulator 10 of FIG. 1A to 1D) accounts for a range of scenarios in which either of the wires 406a and/or 406b may be released and attempt made to hold them in place using the insulators 402a or 402b, for example: pulling the first wire 406a down to hook under the first insulator 402a, or further to the second insulator 402b; pulling the first wire 406a up to hook over the first insulator 402a; pulling the second wire 406b up to hook over the second insulator 402b, or further to the first insulator 402a; or pulling the second wire 406b down to hook under the second insulator 402b.

(31) In each of these cases, the tension in the respective wires 406a and 406b will lead them to slide along the insulators 402a and 402b into contact with the post 404.

(32) The entire disclosures of all applications, patents and publications cited above and below, if any, are herein incorporated by reference.

(33) 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.

(34) 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.

(35) 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.

(36) 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.

(37) 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.