Embodiments described herein relate to fencing apparatus and methods, including electric fencing insulators and methods of manufacture thereof.
Fencing materials and methods have developed over hundreds and thousands of years and continue to evolve. Fencing is used to contain livestock, to maintain a separation between species, to exclude livestock and other animals from crops, etc. Fence posts and fencing material between posts may be constructed of a variety of materials including wood, steel, composites, and others. A combination often-used in modern farm and ranching operations is steel fence posts supporting various types and numbers of strands of wire strung between posts. Straight or barbed wire may be used, for example. Barbed wire may deter animal crossing as it is sharp and may be painful for an animal attempting to cross a barbed-wire fence. Another technique that may be effective using a small number of strands is electric fencing. One or more electrically conductive strands are energized at a high voltage but are current-limited to create a strong electric shock without harming an animal attempting to cross. One complicating factor with electric fencing is the need to electrically insulate each energized strand of wire and any conductive retaining wires used to fasten the energized strand at each fence post to prevent current leakage to ground through the fence post.
The steel t-post is a fence post designed for wire fencing.
Some t-post designs may also have a series of nubs (e.g., the nub 150) protruding from the cross member 120 on the side of the cross member 120 opposite the junction 130 of the vertical member 110 and the cross member 120. Some t-posts may be designed with extensions 120A and 120B of the cross member 120 extending from the flat vertical member 110 at an angle other than 90 degrees. Other t-posts may be designed with the extensions 120A and 120B curved slightly toward the nubs 150, forming a concave area populated by the nubs 150 along the length of the t-post. Each of several fencing wires is generally positioned at the bottom of an appropriate nub. The fencing wire is fastened at that position along the length 140 using a separate retaining wire wrapped around the fence wire and the edges of the vertical member 110 and the two edges of the cross member 120. The nubs in conjunction with the retaining wire thus alleviate vertical slippage of the fencing wire along the length of the t-post.
In some cases, t-posts are used to implement electric fences. In that case, an insulator is required to be fitted to each section oft-post at points touched by an electric fence wire to be energized and/or by a conductive retaining wire wrapped around the fencing wire and the fence post. Insulators may be fabricated from various electrically insulating materials including glass and plastic. Plastic insulators are known which snap around the two edges of the extensions 120A and 120B of the cross member 120 and extend outward from the wire surface side 170 of the t-post 100. Such insulators thus form a lever arm outward from the t-post surface 170. Livestock may come into contact with and dislodge such “extension type” insulators from the t-post due to the lever arm effect.
“Sleeve” type insulators are also known. Such insulators slide down from the top of the fence post during installation and prior to fastening the fencing wires to the fence post.
Apparatus and methods described herein provide electrical insulation between an electrically energized fencing wire and a point of contact of the wire with a grounded fence post. Insulators disclosed herein form a band of electrically insulating material with a lateral opening to position around a periphery of the fence post and along a length of the fence post as determined by the length of the insulator. Embodiments of the disclosed apparatus include a fastener at the opening. The fastener is snapped to a secure closed position using a simple clipping motion after the insulator is positioned around the fence post at a selected height along the fence post length. Embodiments of the disclosed electric fence insulator thus form a minimal lever arm between the fence post and the energized wire and are more mechanically secure than prior-art devices as a result.
Additionally, disclosed embodiments of the insulator may be retrofitted to existing installations with fencing wire already installed. It may be advantageous to install a fence post insulator without the need to access the length of the fence post from the top of the post to the section requiring electrical insulation. For example, an electric fence requiring repair may simply need an insulator replaced at a wire other than the top wire. Wires and other hardware above the point of repair may prevent sliding an insulator onto the fence post from the top of the fence post.
Some embodiments described herein, or portions of such embodiments, may be fabricated from a stretchable band of electrically insulating material such that, when fastened around a section of a fence post as described above, may contact only convex portions of the fence post cross section and leave a gap between the fence post and the band of insulating material along concave portions of the fence post as viewed in cross-section.
Some examples described and illustrated herein refer to embodiments used with t-post types of fence posts. However, embodiments of the invention are not limited to use with t-posts. The invented insulator may be formed in any shape to conform to or be positioned around the cross-sectional shape of any fence post, whether metallic, wooden, composite, or fabricated from some other material.
However, it is noted that embodiments of the insulator apparatus 200 are each fabricated as a band of electrically insulating material to surround a section of fence post and thus to conform to the number and shapes of the sides of the fence post along a section of the fence post corresponding to the height of the insulating band. Thus, the insulator apparatus 200 may vary in shape and size according to the shape and size of the fence post. In the case of a round cross-sectional shaped fence post, for example, the band of the insulator apparatus 200 is formed in a rounded cross section to surround and grasp the round cross-sectional shaped fence post along a longitudinal section of the fence post.
The insulator apparatus 200 may be manufactured in various lengths, the length being the drawing dimension orthogonal to the drawing sheet surface and continuing downward from the drawing sheet surface. The insulator apparatus 200 is constructed as a band of electrically insulating material to position around a longitudinal section of a fence post such as to electrically insulate one or more conductive fencing wires 208 positioned perpendicular to the longitudinal section of the fence post to be insulated from the fencing wire(s) 208.
The band of the insulator apparatus 200 is fabricated from a plastic, composite, or other mechanically conformal and electrically insulating material of sufficient insulating strength to substantially prevent current flow from the charged fencing wire 208 through the fence post and to ground. The insulator apparatus 200 includes a lateral opening 210 along its length so that the flexible band of the insulator apparatus 200 may be bent open to install around the fence post prior to fastening as described below. Some embodiments of the insulator apparatus 200 may be hinged with one or of more hinges 213 positioned at one or more positions along the periphery 214 of the insulating band of the insulator apparatus 200. An axis of such hinge lies perpendicular to the periphery 214 of the band and facilitates installation around a fence post of large cross-sectional area to avoid excessively deforming or breaking the insulator apparatus 200 during installation.
Embodiments of the insulator apparatus 200 include one or more fastener(s) 215 to secure the insulator apparatus 200 at a selected longitudinal position along the length of the fence post. The fastener 215 may be of various types, including a hooked clip fabricated along one vertical edge of the insulator apparatus 200 to slide into a recess or around a raised edge fabricated at a matching position along the opposite vertical edge of the insulator apparatus 200. In some embodiments, the fastener 215 may include matching convex-shaped hooks fabricated along matching vertical edges of the insulating band forming the apparatus 200 as shown in
Embodiments of the insulator sheet 300 may include various types of fastener devices as previously mentioned, including but not limited to clip-into-recess fasteners 310A/315A and 310B/315B as shown. Although two fasteners are shown in the example insulator sheet 300, various embodiments of the insulator sheet 300 may include an appropriate number of fasteners as determined by the longitudinal length 320 of the insulator sheet 300 and the strength of each fastener as designed to appropriately secure the insulator apparatus 200 to the fence post.
In the case of embodiments of an insulator apparatus for use with a t-post, upon installation the insulator apparatus will cover, insulate and make unavailable nubs 150 formed on the t-post as previously described. In replacement, nubs (e.g. the nub 325) may be formed at a surface of the insulator sheet 300. Said nubs 325 may be formed during the extrusion process or during a post process operation. The nubs 320 may be formed from the same plastic as the insulator apparatus 200 or may be formed from a different material and later affixed to or molded into the insulator sheet 300. The nubs 325 provide a surface against which a fencing wire may rest or be pulled tight, as was described for the nubs 150 associated with the t-post 100.
The extruded t-post insulator sheet 300 is cut to the length 320 corresponding to the desired longitudinal length of the insulator apparatus 200. Before or after cutting to length, the insulator sheet 300 flows through a forming device. The forming device makes the appropriate bends at the crease lines and stabilizes the bend angles as appropriate to the cross-sectional shape of the fence post. Stabilization may be achieved using cement, melting material along the crease lines, plastic welding, etc.
Some embodiments of the insulator apparatus 400 include hook-shaped perimeter ends 415A and 415B at the previously-mentioned lateral opening 210. The hook-shaped perimeter ends 415A and 415B form an embodiment of the fastener 215 described with reference to
Longer-length embodiments may result in higher materials cost, however. Some embodiments of the insulator apparatus 400 may include lateral retaining slots (e.g., the lateral retaining slots 515A and 515B) fabricated into a portion of the thickness of the insulator apparatus 400. The retaining slots may be fabricated at convex extension areas of the insulator apparatus 400 at positions where the fencing wire 208 and/or the above-described retaining wire (e.g., retaining wire section 520) are anticipated to contact the insulator apparatus 400 when the fencing wire 208 and the retaining wire are tensioned. The retaining slots may improve the trade-off between reliability of maintaining the energized wires on the electrically insulating apparatus 400 and increased materials cost resulting from a longer length dimension 510.
Various embodiments of the insulator apparatus (e.g., the embodiments 200 and 400) may be fabricated according to various methods, including injection molding or extrusion followed by slicing a longer extruded product into shorter sections.
The apparatus of various embodiments may be useful in applications other than providing electrical insulation of fencing and/or retaining wires from grounded fence posts used in electric fence applications. Thus, various embodiments of the invention are not to be so limited. The illustrations of the insulating apparatus 200 and 400 and of the intermediate product of manufacture 300 are intended to provide a general understanding of the structure of various embodiments. They are not intended to serve as a complete description of all the elements and features of apparatus and systems that might make use of the structures described herein. The novel apparatus of various embodiments may be incorporated into various systems and methods of fencing.
It is noted that activities described herein may be executed in an order other than the order described. The various activities described with respect to methods identified herein may also be executed in repetitive, serial, and/or parallel fashion.
Apparatus and methods described herein surround a longitudinal section of a grounded fence post with a band-shaped insulator apparatus with a lateral opening and a fastener at the opening. The insulator apparatus electrically insulates fencing wire and/or retaining wire positioned at the longitudinal section from the grounded fence post supporting the wire. Increased durability and reliability may result from the absence of or shortened length of a lever arm between the insulator and the fence post.
By way of illustration and not of limitation, the accompanying figures show specific embodiments in which the subject matter may be practiced. The embodiments illustrated are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other embodiments may be used and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. This Detailed Description, therefore, is not to be taken in a limiting sense. The breadth of various embodiments is defined by the appended claims and the full range of equivalents to which such claims are entitled.
Such embodiments of the inventive subject matter may be referred to herein individually or collectively by the term “invention” merely for convenience and without intending to voluntarily limit this application to any single invention or inventive concept, if more than one is in fact disclosed. Thus, although specific embodiments have been illustrated and described herein, any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments and other embodiments not specifically described herein will be apparent to those of skill in the art upon reviewing the above description.
This application claims the benefit of priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/801,655 titled “T-Post Insulator Apparatus and Methods” filed on Mar. 15, 2013 and incorporated herein by reference in its entirety.
Number | Date | Country | |
---|---|---|---|
61801655 | Mar 2013 | US |