WO1998032328A2

WO1998032328A2 - Improvements in and relating to fencing apparatus

Info

Publication number: WO1998032328A2
Application number: PCT/NZ1998/000004
Authority: WO
Inventors: Richmond Balcombe Spencer; Paul Clifford Reid
Original assignee: Gallagher Group Limited
Priority date: 1997-01-29
Filing date: 1998-01-22
Publication date: 1998-07-30
Also published as: ZA98536B; WO1998032328A3; AU5783198A

Abstract

The present invention uses an electric fence support (1) which includes at least one indentation (2) located along the length of the fence support (1), and an insulator (20) including a locator and a wire retainer, wherein the insulator includes one or more lugs (12) adapted to cooperate with one or more indentations (2) in an electric fence support (1). A method of constructing a security system is also disclosed.

Description

IMPROVEMENTS IN AND RELATING TO FENCING APPARATUS

TECHNICAL FIELD

This invention relates to improvements in electric fencing apparatus. Specifically the invention may be applied to electric fences installed for security reasons.

Reference throughout this specification will be made to the fencing apparatus as being applied to electric fences used for security purposes. However, it should be appreciated that the invention can be applied to other electric fences, not necessarily electric fences employed in security applications.

BACKGROUND ART

Electrified fences have proven very popular and effective in many applications. They provide an effective barrier which may be used, for example to retain livestock or captive persons within a region. Alternatively, electric fencing may be used as a barrier to prevent unauthorised persons from entering a region.

Electric fencing has proven popular in these applications because of the limited amount of materials required to construct an effective barrier. The fence constructed need not be overly robust or strong, as the voltage applied to the fence wires discourages contact with the fence through delivery of a painful shock.

In most instances the supporting rods of an electric fence need to be resilient enough to resist tampering by an intruder, and be able to spring back into its original position after an applied force has been removed from the fence.

Electric fences also employ insulating devices located on supporting fence posts or rods. The insulating devices attach and retain a fence wire to a support rod, while electrically insulating the support rod from the fence wire. Electric fence insulators also act to retain the fence wires a certain distance apart from one another to ensure the wires are positioned evenly at regular intervals. An important feature of an insulator is its ability to retain the fence wire a set distance from the other fence wires. The insulator must resist forces which may displace the fence wire up or down the support rod, whether these forces result from wind and weather conditions, livestock or an intruder trying to displace fence wires enough to negotiate the fence.

Presently a number of electric fence insulators and associated fence supports have been developed.

Several types of electric fencing systems have been developed which fix an insulator to the body of a supporting rod via a pin or bolt driven through holes in the rod. This pin or bolt may then be secured to the opposite side of the rod with, for example wing nuts, retaining pins or clips.

Several problems are associated with this design of insulator and fence rod.

The method of attaching the insulator to the rod requires holes to be driven through the rod. This makes the fence rod difficult and expensive to manufacture as well as weakening in the rod slightly. In addition, low grade steel, such as mild steel, is used to construct the fence post. Mild steel is used in the main because stronger grades of steel make it extremely difficult to machine or punch the pin or bolt holes into the post.

A large amount of mild steel is also used to construct a fence post than would normally be required when stronger steel is used. More steel must be used to ensure the fence post possesses the required resilience and strength for security fence applications.

An alternative to the above insulator and post electric fence system is a clamp on insulator which is attached to a solid metallic rod. This system provides the required resilience and strength to the fence rod while allowing high grades of steel to be used to construct a compact rod. Clamping insulators may be attached to the fence rod via an enveloping sleeve which has its outer edges pulled tightly together by a screw, or nut and bolt arrangement, or by the inbuilt shape of the insulator. As with the first fencing system use of the clamped fence insulator and rod cause a number of problems.

The insulator used is highly susceptible to slipping movement ups and down the fence rod. This allows the fence wires to spread unevenly up and down the length of the rod, possibly creating large gaps in the fence structure. An intruder may also take advantage of this weakness by pushing fence wires apart and passing through the fence without contacting a live electric fence wire.

Another electric fence system currently used is the kinked fence rod and corresponding insulator employed in the agricultural industry. The kinked fence rod is substantially straight but shaped with kinks along its length. An insulator may be clamped onto the kinked rod with the clamping portion of the insulator shaped to fit around one kink in the rod. One or two retaining lug pins are used on the clamp to and hold both sides of the clamp together around a rod held in the insulator.

The insulator is held in place by the kinked shape of the rod as the kink cannot be forced past either of the retaining pins or the kinked cradling section of the clamp base.

However, the fence rod and cradling insulator again involves a number of disadvantages for the fence system manufacture and end user. The kinks in the fence rod are manufactured by stamping or pressing the required shape into an initially straight rod. However, the forces applied during the stamping process act to bend the rod from its initially straight shape. Rods manufactured using this process may acquire a bend in their overall shape, with the amount of deviation varying from rod to rod.

As the kinked fence rods are not homogeneous in shape it is difficult to ensure that fence wires are retained at regular intervals along a fence line. The variable bend in each rod ensures a degree of variation occurs in a positioning of fence wires along the length of the fence.

Experimentation in the materials used as electric fence support rods has also been conducted. Several materials other than steel have been employed as electric fence support rods. For example a number of different alloys of metal, fibreglass and other composite materials as well as varying grades of steel have been trialed as electric fence rods.

However, for security applications the resilience and strength of the rod is an extremely important factor. In most cases only high grade steel is suitable as the material used to construct to the fence rod, due to its high resilience and strength.

One problem associated with high grade steels is the strength of the steel, which makes manufacturing of appropriately shaped rods very difficult. Expensive tools are regularly broken or damaged when attempts are made to punch holes in a high strength steel rod.

It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.

Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

DISCLOSURE OF INVENTION

According to one aspect of the present invention there is provided an electric fence support for supporting one or more electric fence insulators,

characterised in that the fence support includes indentations located along the length of the support.

According to another aspect of the present invention there is provided an insulator capable of attachment to an electric fence support substantially as described above, wherein the insulator includes a locator and a wire retainer,

characterised in that the insulator includes one or more lugs that can cooperate with one or more indentations in an electric fence support.

According to another aspect of the present invention there is provided a method of manufacturing an electric fence support substantially as described above, characterised in that material is removed from the support to form indentations in the support.

According to another aspect of the present invention there is provided a security system including electric fence supports and insulators substantially as described above,

characterised in that the fence supports have indentations located along the length of the support, and

the insulators include one or more lugs that can cooperate with indentations in the electric fence supports.

According to another aspect of the present invention there is provided a method of constructing a security system including at least one electric fence support with indentations located along the length of the support,

one or more electric fence wires,

and at least one insulator including a locator, a wire retainer and one or more lugs capable of cooperating with one or more indentations in the electric fence support,

the method of constructing a security system including the steps of:

a) securing one or more fence supports perpendicular to a surface, and

b) locating at least one insulator on one or more fence support using lugs on the insulator cooperating with indentations in the electric fence support, and

c) retaining an electric fence wire within an insulator wire retainer,

In a preferred embodiment of the present invention an electric fence support may be a solid rod which extends to the height required for an electric fence. A solid rod may be easily manufactured and provides a strong resilient fence support. However it should be appreciated that other embodiments of the present invention may not use solid rods as fence supports. For example any length of material of any particular cross-section may be used in conjunction with the invention as a fence support.

Reference throughout the specification shall now be made to the fence support as being a fence rod. However, this should in no way be seen as limiting, as the invention may be constructed using other forms of fence support, not necessarily solid rods.

In a preferred embodiment of the present invention the fence rod may be constructed from spring steel. Spring steel is a high grade steel which is very strong and resilient. A spring steel fence rod will spring back into its original position after a force is applied to the rod, where in most instances, a rod constructed from lower grade steel would be deformed or bent out of place.

Alternative embodiments of the present invention may not employ spring steel to construct the fence rod. For example, other embodiments may employ lower grades of steel, fibreglass, or other composite materials to form a fence rod.

Reference throughout the specification shall now be made to the fence rod as being constructed from spring steel. However, it should be appreciated by those skilled in the art that this should in no way be seen as limiting the types of materials which can be used to construct the fence rods.

In a preferred embodiment of the present invention indentations may be formed in a fence rod by material being removed from the fence rod rather than reshaping the rod. Removing material from the fence rod ensures that the indentations in the rod are manufactured quickly and precisely. Removing material also ensures that the bending or twisting effect occurring when a rod is stamped, pressed or bent is reduced.

In a preferred embodiment of the present invention, where the fence rod is constructed from spring steel, material removed from the rod forming an indentation may be removed with use of specially hardened cutting tools. These tools are specifically adapted to cut through spring steel to form an indentation where normally tools used with lower grades of steel would easily break or chip.

In a preferred embodiment of the present invention an indentation formed in a fence rod may be substantially rectangular in shape. In a further preferred embodiment of the present invention the top edge of the rectangular indentation formed may be angled with respect to the bottom edge of the indentation.

This angling of one indentation edge reduces the stress forces applied to the manufacturing tool when the indentation is formed. The top edge of the tool used is angled to a shape corresponding to that of the indentation required. This allows transmission of stress away from the top corner of the tool during the manufacturing process, reducing the chance of the tool breaking when used.

In a preferred embodiment indentations may be located along the entire length of a fence rod, on both sides of the fence rod. Locating indentations in this manner allows the manufacturing process to form multiple indentations at the same time, thereby balancing the cutting forces applied to either side and end of the rod. This balancing of applied forces reduces the bending effect that indentation manufacturing may have on the fence rod.

In this way 'groups' or 'sets' of indentations may be formed along the length of a rod.

Insulators are provided on electric fence systems to retain an electrified fence wire in a certain position relative to a supporting fence rod or post. The insulator ensures that the electrical current carried by the fence wire does not leak down through the fence support into the ground, reducing the effectiveness of the electric fence. Consequently electric fence insulators are constructed from electrically insulating materials, and are configured to physically displace the fence wire from the fence support, but still retain the fence wire in position on the fence support.

In a preferred embodiment of the present invention the electric fence insulator may be constructed from insulating plastic material. Using plastics material allows the insulator to be manufactured using mass production technology. Plastic materials may be used to form the insulator using injection moulding techniques, ensuring the insulator is manufactured at low cost with high uniformity and reproducibility.

Alternative embodiments of the present invention may not employ plastics materials to construct the insulator. For example, any electrically insulating material may be used to construct the insulator provided the material is physically strong enough to retain a wire in place against a fence rod.

In a preferred embodiment of the present invention the insulator includes a wire retainer. A wire retainer acts to hold an electric fence wire in place against the insulator and fence rod. In a further preferred embodiment of the present invention the wire retainer included in the insulator may consist of two hooked arms positioned side by side, with one arm inverted relative to the other. This configuration of wire retainer allows a fence wire to be threaded through the two arms, where one arm prevents upwards movement of the wire and the other arm prevents downward movement of a wire.

It is envisioned this embodiment of the wire retainer may be used to attach to fence wire in the middle of a fence, where the fence wire continues on either side of the insulator.

The person assembling the fence system may easily thread a wire between the two retaining arms to limit movement of the wire up and down the fence rod.

An alternative embodiment of the present invention the wire retainer may be a loop of material terminating against the body of the insulator. A fence wire may be threaded through the retaining loop with one end of the wire being wound around the other side of the wire and fixed in place. The other side of the wire may then be pulled tight and threaded through insulators located on other fence rods. It is envisioned this embodiment of the wire retainer may be used where the fence line is to be terminated. However, other embodiments may not employ either of the wire retainer designs disclosed above. It should be appreciated by one skilled in the art that many different types of wire retaining devices may be used, with the invention not necessarily being limited to the embodiments disclosed above.

In a preferred embodiment of the present invention the insulator includes a locator to attach the insulator to a fence rod and prevent the insulator from sliding up and down the fence rod. In a further preferred embodiment of the present invention the locator may consist of a U-shaped sleeve which fits around a fence rod, with each edge of the sleeve tapering inwards on the open end of the sleeve. A fence rod may be pushed into the sleeve by forcing apart the other sleeve edges slightly and seating the rod against the inner walls of the sleeve.

In a further preferred embodiment of the present invention there may be provided a locking device to ensure the fence rod cannot be shifted out of the locator once inserted. Such a locking device may be for example a pin or nut and bolt arrangement passed through the outer edges of the sleeve, or a threaded clamping arrangement which may be tightened to pull the two edges of the sleeve closer together.

Reference throughout the specification shall now be made to the locator as being a U- shaped sleeve employing a split pin pushed through holes in either edge of the sleeve to lock a fence rod into the sleeve. However it should be appreciated by those skilled in the art that many different types of locator may be used in conjunction with the invention, and should not necessarily be limited to those disclosed above.

In a preferred embodiment of the present invention there are provided lugs on the inside surface of the U-shaped locator sleeve. These lugs are shaped to fit inside corresponding indentations located in a fence rod.

The lugs provided may act to engage indentations in a fence rod to prevent the insulator sliding up or down the rod.

The fence system may be assembled firstly by placing a fence rod in the required position and orientation, then installing insulators at points on the fence rod. The sleeved locators of each insulator may be slid onto a fence rod and the lugs on each side of the sleeve pushed into the corresponding indentations of the fence rod. At this point a pin may be inserted through a hole in the outer edges of the locator sleeve, locking the rod inside the locator.

In this manner movement of the insulator up or down the fence rod is prevent via the lugs engaging with indentations on the fence rod. The locator is also locked on the fence rod with the locking pin, preventing horizontal movement of the insulator.

An intruder may try to apply large forces to an insulator by standing on the insulator, trying to spread fence wires to provide a gap in a fence. The use of lugs and complementary indentations prevents an intruder from gaining passage through a fence, as the lugs and indentations securely lock the insulator in place. As the bottom edge of the fence rod in the preferred embodiment is not angled, downward pressure on the insulator is strongly resisted by the lug and indentation combination.

The invention as disclosed above also prevents the insulator from being twisted in a circular manner. The plastic comprising one entire edge of a lug needs to be compressed significantly before any twisting movement occurs in the insulator.

In a preferred embodiment of the present invention there is provided three lugs per insulator and locating sleeve. These three lugs are configured to engaged three complimentary indentations located at the required positions on a fence rod.

In a further preferred embodiment where three lugs are provided per locator sleeve, two lugs are position on one side of the sleeve, with the third lug being position on the opposite side of the sleeve between the two other lugs. This configuration of lugs ensures the insulator is strongly located in one position on a fence rod and can withstand large applied forces before it begins to shift. In a preferred embodiment of the present invention the surface to which a fence rod is secured may be the top of a fence wall or building roof. This allows a small electric fence to be erected on top an existing barrier to provide extra protection to an enclosed area. An intruder firstly needs to scale a tall obstacle, and then contend with wires electrified with high voltages.

Alternative embodiments of the present invention may not employ walls fence tops, or roofs as the surface to which a fence rod may fixed. For example other embodiments may include fence rods secured to concrete, earthen or wooden surfaces. In another alternative embodiment fence rods may be attached to a vertical surface in a horizontal orientation to protect for example, horizontal windows or skylights.

In a preferred embodiment of the present invention there may be provided additional notches located on the lower end of a fence rod to cooperate with fixing devices used to fix a fence rod to a surface.

For example, in some embodiments fixing devices such as angled brackets or metallic saddles may include locating sleeves and lugs to attach the fixing device to the fence rod, and hence to a surface.

The present invention as disclosed above has many advantages over the prior art. Fence rods as disclosed may be constructed using spring steel to provide strong resilient fence rods which do not require large amounts of material to construct the rod.

The fence rod and insulator system may be easily and cheaply mass produced as well as quickly and simply installed by a fence system user.

The complimentary lug and indentation locating scheme provides a simple and strong method of holding a insulator in one place on a fence rod.

A fencing system composed of the elements disclosed above may be easily installed in most locations where required. It may also be employed as an additional barrier to intruders when situated on top of a fence, wall or building roof. BRIEF DESCRIPTION OF DRAWINGS

Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which:

Figure 1 illustrates a fence support employed in one embodiment of the present invention, and

Figure 2 illustrates a cross-sectional view of a locator sleeve and associated lugs employed in one embodiment of the present invention, and

Figure 3 illustrates a cross-sectional view of a locator sleeve and attached support rod section employed in one embodiment of the present invention.

BEST MODES FOR CARRYING OUT THE INVENTION

Figure 1 illustrates a fence support used in one embodiment of the present invention, shown by fence rod 1.

Fence rod 1 includes indentations 2a, 2b and 2c. The indentations 2 are positioned at different points and alternate sides along the fence rod 1. This ensures the fence rod 1 is not unduly weakened at one point by the combined reduction of its width by two overlapping indentations 2.

The fence rod 1 in this embodiment is eight millimetres in diameter. The proportion of the indentations 2 are arrived at from a compromise between having the indentations 2 too large and weakening the rod 1 and having the indentations 2 too small resulting in poor insulator retention. It should be appreciated that other rod sizes may be used. However, the applicant has found that larger rod diameters can be expensive.

Each indentation includes an upper side wall 3 and a lower side wall 4. Each upper side wall 3 is angle with respect to the lower side wall 4. This angling of the upper side wall 3 allows a custom designed press tool to be used to form each indentation 2, reducing the stress applied to the tool tip corners during manufacturing of the fence rod 1. The feed of the rod is PLC controlled for flexibility of spacing.

Figure 2 illustrates a rear view of an insulator generally indicated by arrow 20.

The lugs 12 can be clearly seen protruding from the locator sleeve 13. It can be seen that each lug 12 is positioned so that there is no corresponding overlap of lugs 12 on the opposite side of the locator sleeve 13.

The locator sleeve 13 has an aperture (not clearly shown) through which a pin 14 can pass. The pin 14 in this figure is shown attached to the insulator 20. The pin can be readily detached by twisting the pin 14 and used.

The back of the insulator portion 15 can be seen in Figure 2. In preferred embodiments, there is provided an insulator finger (not shown) on the front of the back 15 for supporting the fence wire.

Figure 3 illustrates a cross-sectional view of a locator and fence rod showing lugs engaging the fence rod indentations.

The fence rod 1 is substantially the same as that disclosed in figure 1, as is the case with the locator 11.

Lugs 12 on either side of the locator 11 act to engage indentations 2 located on either side of the fence rod 1.

When the lugs 12 are engaged in the indentations 2 movement of the locator 11 and hence the entire insulator (not shown) is limited as the lugs 12 catch and hold on the edges of indentations 2.

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

THE CLAIMS DEFINING THE INVENTION ARE;

1. An electric fence support for supporting one or more electric fence insulators, characterised in that the fence support includes at least one indentation located along the length of the fence support.

2. An electric fence support as claimed in claim 1 wherein the fence support is formed from a rod of spring steel.

3. An electric fence support as claimed in either or claims 1 or 2 which includes at least one substantially rectangular shaped indentation along the length of the fence support wherein one edge of an indentation is angled.

4. An electric fence support as claimed in any one of claims 1 to 3 wherein indentations are located along the length of the fence support on both sides of the fence support, with each indentation formed being grouped with at least one indentation on the opposite side of the fence support.

5. An insulator capable of attachment to an electric fence support as claimed in any previous claim wherein the insulator includes a locator and a wire retainer,

characterised in that the insulator includes one or more lugs adapted to cooperate with one or more indentations in an electric fence support.

6. An insulator as claimed in claim 5 wherein the wire retainer includes two hooked arms positioned side by side with one arm being inverted with respect to the second arm.

7. An insulator as claimed in either of claims 5 or 6 which includes a locator shaped as a tapered U-shaped sleeve configured to fit around an electric fence support.

8. An insulator as claimed in any one of claims 5 to 7 wherein the locator includes lugs adapted to fit inside corresponding indentations in and electric fence support.

. An insulator as claimed in claim 8 which includes three lugs with two lugs positioned on one side of the locator and a third lug positioned on the opposite side of the locator between the other two lugs.

10. A method of manufacturing electric fence support characterised in that material is removed from the fence support to form indentations in the fence support.

11. A security system including electric fence supports as claimed in any previous claim, the security system characterised in that the fence supports include insulators located along the length of the support and the insulators include at least one lug adapted to cooperate with at least one indentation in the electric fence support.

12. A method constructing a security system including at least one fence support as claimed in any one of claims 1 to 4, and one or more electric fence wires, and at least one insulator as claimed in any one of claims 5 to 9,

the method of constructing a security system characterised by the steps of;

a) securing one or more fence supports perpendicular to surface, and

b) locating at least one insulator on one or more electric fence support using lugs on the insulator cooperating with indentations on the electric fence support, and

c) retaining an electric fence wire within an insulator wire retainer,

13. An electric fence support substantially as herein described with reference to the accompanying drawings and or examples.

14. An insulator substantially as herein described with reference to the accompanying examples and/or drawings.

15. A method of constructing a security system substantially as herein described with reference to the accompanying drawings and/or examples.

16. A method of manufacturing electric fence support substantially as herein described with reference to the accompanying drawings and/or examples.

17. A security system substantially as herein described with reference to the accompanying drawings and/or examples.