Electric fence insulator

Abstract

An insulator for an electric fence, an electric fence system using the insulator, and a method of installing same are disclosed herein. The insulator includes a body having a first end and a second end, and a wire attachment portion positioned at the first end of the body. A passage passes through the wire attachment portion, the passage including a first open end, a second open end, and a waist region between the first open end and the second open end. The diameter of the passage at the first open end and the diameter of the second open end are both greater than at the waist region.

Claims

1. An insulator for an electric fence having at least one wire, the insulator including: a body having a first end and a second end; a wire attachment portion positioned at the first end of the body; and a post connector portion at the second end of the body operable for connecting the insulator to a fence post, wherein the wire attachment portion includes a passage passing through the wire attachment portion, the passage including a first open end, a second open end, and a narrow central waist region between the first open end and the second open end, wherein the diameter of the passage at the first open end and the diameter of the second open end are both greater than at the narrow central waist region, and wherein the passage flares outwardly from the narrow central waist region to the first open end and the second open end, in a curved flare, wherein the body, the wire attachment portion and the post connector portion are made of an electrically insulating material, and wherein the insulator is molded as a unitary part, wherein the wire attachment portion includes a wall having an interior surface defining the passage, and an exterior surface, wherein at least a portion of the exterior surface of the wall between the passage and the body of the insulator is shaped to approximate a shape of the interior surface of the wall, and wherein the body is connected to the exterior surface at the narrow central waist region such that an electrical creepage path, from the passage to the fence post to which the insulator is connected, passes along the exterior surface and across the body.

2. The insulator of claim 1, wherein the cross section of the passage is substantially circular in shape along its length.

3. The insulator of claim 1, wherein the passage is substantially in the shape of a hyperboloid.

4. The insulator of claim 1, wherein the diameter of the passage at the first open end and the second open end is about 40 mm to 50 mm.

5. The insulator of claim 1, wherein the length of the passage between the first open end and the second open end is about 40 mm to 50 mm.

6. The insulator of claim 1, wherein the thickness of at least a portion of the exterior surface of the wall between the passage and the body of the insulator is less than about 3 mm.

7. The insulator of claim 6, wherein the thickness of at least a portion of the exterior surface of the wall between the passage and the body of the insulator is less than about 1 mm.

8. The insulator of claim 1, wherein the passage has a first longitudinal axis between the first open end and the second open end, and the wire attachment portion includes a second passage having a second longitudinal axis transverse to the first longitudinal axis.

9. The insulator of claim 8, wherein the second passage is located at a position distal from the body relative to the passage having the first longitudinal axis.

10. The insulator of claim 1, wherein the wire attachment portion includes a cross member on an exterior surface of the wire attachment portion distal from the body, the cross member extending between the first open end and the second open end of the passage.

11. The insulator of claim 1, wherein the wire attachment portion is made of an electrically insulating material.

12. The insulator of claim 1, wherein at least the body and the wire attachment portion are manufactured as a unitary part.

13. The insulator of claim 12, wherein the insulator as a whole is manufactured as a unitary part.

14. An electric fence system, including: at least one fence post; at least one insulator to be secured to the fence post, wherein the at least one insulator includes: a body having a first end and a second end; a wire attachment portion positioned at the first end of the body; and a post connector portion at the second end of the body operable for connecting the insulator to a fence post, wherein the wire attachment portion includes a passage passing through the wire attachment portion, the passage including a first open end, a second open end, and a narrow central waist region between the first open end and the second open end, wherein the diameter of the passage at the first open end and the diameter of the second open end are both greater than at the narrow central waist region, and wherein the passage flares outwardly from the narrow central waist region to the first open end and the second open end in a curved flare, wherein the body, the wire attachment portion and the post connector portion are made of an electrically insulating material, and wherein the insulator is molded as a unitary part, wherein the wire attachment portion includes a wall having an interior surface defining the passage, and an exterior surface, wherein at least a portion of the exterior surface of the wall between the passage and the body of the insulator is shaped to approximate a shape of the interior surface of the wall, and wherein the body is connected to the exterior surface at the narrow central waist region such that an electrical creepage path, from the passage to the fence post to which the insulator is connected, passes along the exterior surface and across the body; and at least one fence line, provided to pass through the passage of the wire attachment portion of the insulator.

15. The electric fence system of claim 14, wherein: the passage of the at least one insulator has a first longitudinal axis between the first open end and the second open end, and the wire attachment portion includes a second passage having a second longitudinal axis transverse to the first longitudinal axis, and the electric fence system includes a second fence line provided to pass through the second passage.

16. A method of installing an electric fence system, including the steps of: securing at least one insulator to a fence post, wherein the at least one insulator includes a body having a first end and a second end, a wire attachment portion positioned at the first end of the body, and a post connector portion at the second end of the body for securing the at least one insulator to the fence post, wherein the wire attachment portion includes a passage passing through the wire attachment portion, the passage including a first open end, a second open end, and a narrow central waist region between the first open end and the second open end, wherein the diameter of the passage at the first open end and the diameter of the second open end are both greater than at the narrow central waist region, and wherein the passage flares outwardly from of the narrow central waist region to the first open end and the second open end in a curved flare, wherein the body, the wire attachment portion and the post connector portion are made of an electrically insulating material, and wherein the insulator is molded as a unitary part, wherein the wire attachment portion includes a wall having an interior surface defining the passage, and an exterior surface, wherein at least a portion of the exterior surface of the wall between the passage and the body of the insulator is shaped to approximate a shape of the interior surface of the wall, and wherein the body is connected to the exterior surface at the narrow central waist region such that an electrical creepage path, from the passage to the fence post to which the insulator is secured, passes along the exterior surface and across the body; and supporting at least one fence line at the wire attachment portion of the insulator by passing the fence line through the passage.

17. The method of claim 16, wherein the passage of the at least one insulator has a first longitudinal axis between the first open end and the second open end, and the wire attachment portion includes a second passage having a second longitudinal axis transverse to the first longitudinal axis, and the method includes passing a second fence line through the second passage to form a vertical fence element of the fence system.

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 a perspective view of an exemplary insulator;

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

(4) FIG. 2A is a top view of the exemplary insulator positioned on an exemplary fence post;

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

(6) FIG. 3A is a perspective view of a section of an exemplary fence system, and

(7) FIG. 3B is a top view of the section of the exemplary fence system.

DETAILED DESCRIPTION

(8) FIG. 1A illustrates an exemplary insulator 10 for an electric fence. The insulator 10 includes a body 12, having a wire attachment portion 14 at a first end and a post connector portion 16 at its second end. In this embodiment the insulator 10 is moulded as a unitary part of an electrically insulating material such as high density polyethylene (HDPE)—although it should be appreciated that other materials may be used.

(9) The wire attachment portion 14 includes a passage wall 18 defining a first passage 20. The first passage 20 has a first longitudinal axis 22 extending between a first open end 24 and a second open end 26 of the first passage 20.

(10) In the exemplary embodiment illustrated, a crossmember 28 spans the space between the first open end 24 and the second open end 26 of the first passage 20 on the side of the passage wall 18 distal from the body 12. A second passage 30 is defined by a wire retention member in the form of an archway 32, located at a position on the crossmember 28 equidistant from the first open end 24 and the second open end 26 of the first passage 20. The second passage 30 has a second longitudinal axis 34, which is substantially orthogonal to the first longitudinal axis 22 in orientation.

(11) Referring to FIG. 1B, the passage wall 18 has an interior surface 36 defining the shape of the passage 20, and an exterior surface 38 defining the creepage distance from the first open end 24 and the second open end 26 of the first passage 20 to the body 12.

(12) In this exemplary embodiment, the interior surface 36 defining the passage 20 is substantially in the shape of a circular hyperboloid, in which the passage 20 flares out from a narrow central waist region towards the first open end 24 and the second open end 26.

(13) In this exemplary embodiment, the length 40 of the first passage 20 is about 45 mm. It is envisaged that this may allow for the production of external corners in a fence line (as will be described below with reference to FIG. 3A and FIG. 3B) while maintaining a suitable air gap of about 20 mm between the wire and a post (not illustrated in FIG. 1B) having a width of about 50 mm. It should be appreciated that this is not intended to be limiting, and that the length 40 may be modified depending on the width or configuration of the post it is intended to be used with.

(14) The diameter 42 of the first open end 24 and the second open end 26 is about 44 mm, while the diameter 44 at the waist region is substantially 7 mm. The resulting curvature of the interior surface 36 along the first passage 20 accommodates the entry and exit of a wire at a wide range of angles, while ensuring the wire is not bent beyond a minimum radius of curvature within the first passage 20.

(15) In the exemplary embodiment illustrated, this configuration is intended to achieve an angle of wire being not more than about 45 degrees exiting from either side of the passage—giving a total of about 90 degrees of change in direction. There is an about 62.5 degree angle before a wire will hit the outer edge of the passage—at which point kinking may occur. This means the wire will always be resting on a smooth radius inside the passage—within that about 45 degree operational limit. It should be appreciated that the angles described are exemplary, and is not intended to be limiting to all embodiments unless expressly stated.

(16) The exterior surface 38 of the passage wall 18 is shaped to approximate the shape of the interior surface 36. This results in relatively thin wall structure curved to increase the creepage distance to the body 12, and ultimately the post connection portion 16. For example, if a wire (not illustrated) bears against the passage 20 at point 46, dashed line 48 illustrates the creepage path across the exterior surface 38 of the passage wall 18 and body 12. This is significantly greater than if the exterior surface 38 extended straight across to the body 12.

(17) The post connector portion 16 includes a first arm 50 and a second arm 52, separated by a post receiving space 54. The first arm 50 includes a threaded aperture 56, while the second arm 53 includes a stepped aperture 58. In order to secure the insulator 10 to a post (not illustrated in FIG. 1B), a fastener 60 having a threaded shank 62 is inserted through the stepped aperture 58, and through one or more apertures in the post to reach the threaded aperture 56. A fastener engaging member 64 having external threads 66 is screwed into the threaded aperture 56. The threaded shank 62 is in turn screwed into a bore 68 of the fastener engaging member 64, securing the insulator 10 to the post.

(18) FIG. 2A illustrates the exemplary insulator 10 positioned on a conductive fence post 200, with a first wire 202 passing through the first passage 20 (not illustrated in FIG. 2A, but as seen in FIG. 1A and FIG. 1B) of the insulator 10.

(19) As the result of the configuration of the passage 20 as described above, the wire 202 can enter and exit the insulator 10 from any angle within the zone designated ‘a’ without resulting in bending of the wire 202 beyond a radius of curvature set by the passage.

(20) FIG. 2A illustrates the exemplary insulator 10 positioned on a conductive fence post 200, with a second wire 204 passing through the second passage 30 (not illustrated in FIG. 2B, but as seen in FIG. 1A and FIG. 1B) of the insulator 10 in a vertical orientation.

(21) It may be seen that with the second wire 204 being held at substantially the front of the insulator 10, the second wire 204 restricts access to the space 206 between the wire 204 and the leading edge 208 of the post 200. The upper side of the insulator 10 might otherwise be used as a platform for attempting to scale the fence, or the insulator 10 used as an anchor point for hooking horizontal wires (not illustrated) from above, or below.

(22) FIG. 3A illustrates an electric fence system 300, including a series of vertical fence posts 200. A plurality of insulators 10 are secured to each fence post 200. Wires 202 are passed through the first passage 20 (not clearly seen in FIG. 3A, but as illustrated in FIG. 1A and FIG. 1B) of each insulator 10 to provide a series of spaced wires 202 which form a barrier.

(23) FIG. 3B illustrates the electric fence system 300 from a birds-eye view, from which it may be seen that the insulators 10 have been able to accommodate both an internal corner (designated by dashed area 302) and an external corner (designated by dashed area 304) while ensuring that all of the fence posts are located on a first side 306 of the fence system 300 with the wire 202 on the other side 308.

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

(25) 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.

(26) 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.

(27) 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.

(28) 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.

(29) 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.