US3749820A

US3749820A - Electric fence insulator

Info

Publication number: US3749820A
Application number: US00271990A
Authority: US
Inventors: H Langlie; A Berg
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-07-14
Filing date: 1972-07-14
Publication date: 1973-07-31
Anticipated expiration: 1990-07-31
Also published as: CA979088A

Abstract

Our all plastic insulator includes a body having two upwardly facing and forwardly projecting hook-shaped members with a sufficiently resilient central tongue therebetween so that the tongue can be flexed upwardly to permit insertion of the electric fence wire into the two hooks, the tongue thereafter preventing undesired removal of the wire. A threaded barrel extends rearwardly from the body and by reason of an elongated slot tapered at its forward end various diameters of fence posts can be accommodated, a nut on the threaded barrel providing the clamping action. The body is structured so as to shed water effectively and also to provide a relatively long non-conductive path between the charged fence wire and grounded post.

Description

United States Patent Langlie et a1.

1 ELECTRIC FENCE INSULATOR [76] Inventors: Howard Langlie; Albert T. Berg, Jr.,

both of Ellendale, Minn. 56026 [22] Filed: July 14, 1972 [21] Appl. No.: 271,990

[51] Int. Cl. 1101b 17/16, AOlk 3/00 [58] Field of Search 174/158 F, 161 F, 174/163 F, 168,170,174, 175, 211; 24/73 HR, 73 SA, 73 AP, 115 R, 115 G, 115 11,129

R, 129 B, 129 D, 237, 255 C, 255 SL; 248/74 [451 July 31 1973 754,049 8/1956 Great Britain 174/158 F 769,610 3/1957 Great Britain 174/146 781,933 8/1957 Great Britain 174/158 F 1,016,302 Great Britain 174/163 F Primary Examiner-Jammie E. Askin AttorneyStuart R. Peterson [5 7] ABSTRACT our all plastic insulator includes a body having twoupwardly facing and forwardly projecting hook-shaped members with a sufliciently resilient central tongue therebetween so that the tongue can be flexed upwardly to permit insertion of the electric fence wire into the two hooks, the tongue thereafter preventing undesired removal of the wire. A threaded barrel extends rearwardly from the body and by reason of an elongated slot tapered at its forward end various diame ters of fence posts can be accommodated, a nut on the threaded barrel providing the clamping action. The body is structured so as to shed water effectively and also to provide a relatively long non-conductive path between the charged fence wire and grounded post.

17 Claims, 5 Drawing Figures ELECTRIC FENCE INSULATOR BACKGROUND OF THE INVENTION This invention relates generally to electric fence insulators, and pertains more particularly to an insulator of this type having no metallic parts.

SUMMARY OF THE INVENTION One object of the invention is to provide an all plastic electric fence insulator so that any arcing from the fence wire to a portion of the insulator is obviated by reason of the lack of any metal contained in the insulator.

Another object is to minimize the likelihood of arcing between the fence wire and the fence post, an insulator constructed in accordance with the teachings of out invention providing a relatively long dielectric path between the wire and post.

Not only is it an aim of the invention to avoid the use of any metallic parts in the construction of our insula tor, thereby contributing to the insulating characteristics thereof, but the lack of any parts of a ferrous nature eliminates all chances of rusting.

Although the invention has for an object the minimizing of arcing possibilities by providing a tortuous and lengthy path, it is a still further object to provide a compact insulator of relatively small dimensions.

A further object of the invention is to provide an insulator that will readily shed moisture, the insulator being configured so as to provide an effective run-off of any water, which moisture, if allowed to collect, would provide a conductive path from the wire to the post.

Yet another object is to provide an insulator that can be easily and quickly attached to a fence post, the insulator being capable of being mounted at virtually any elevation thereon without the use of any metallic fasteners.

Still further, an object is to provide an insulator that will accommodate various sizes of posts, yet permit the secure clamping of the insulator thereto. Also, it is an aim of the invention to accommodate all wire sizes normally used in electric fence installations, including twostrand barbed wire.

Further, the invention has for an object an insulator involving simplified molding techniques. I

An additional object is to provide an insulator that will permit the installer to attach an already tightened fence wire, yet effectively prevent its inadvertent re lease.

A further object is to provide a fence insulator that can be attached to a fence post without tools and in which the fence wire can in turn be attached to the insulator without tools.

Briefly, our invention envisages the employment of a threaded clamping means that enables the user to adjust the insulator vertically on a round post of any conventional size, the insulator being capable of accommodating posts of different cross sections. The body of the insulator is configured so as to provide sloping surfaces which readily shed water, thereby minimizing the chances of moisture collecting on the surfaces of the insulator. Extending forwardly from the body are two hook-shaped jaws and an intermediate resilient tongue t for receiving the fence wire therein. The intermediate tongue, which faces downwardly, is sufficiently resilient so that it can be flexed upwardly to permit the insertion of the wire; More specifically, curved surfaces 1 on the two jaw members permit an upward camming of the tongue when the fence wire is forced thereagainst.

BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE PREFERRED EMBODIMENT The perspective view constituting FIG. 1 shows our electric fence insulator in its entirety, the insulator having been generally denoted by the reference numeral 10. The insulator 10 is pictured as being clamped at a preferred elevation to the upper portion of a round post 12 and a section of fence wire 14 is shown as being held or gripped by the insulator. Although shown as a single unbarbed strand, it will be appreciated that it may be double-stranded barbed wire; also it may be of any conventional gauge.

Prior to describing the insulator 10 in detail, it is to be understood that the entire insulator is fabricated from plastic, preferably linear polyethylene. In other words, the insulator 10 includes no metallic parts whatsoever, the only metallic or conductive elements being the post 12 and wire 14.

Describing the insulator 10 with greater particularity, it will be noted that the insulator 10 comprises a vertical panel 16 at the front of a body 17. Projecting from the vertical panel 16 are three

members

18, 20 and 22. These

members

18, 20 and 22 are molded integrally with the face plate or panel 16.

The

members

18, 22 constitute hook-shaped jaws which face upwardly, having semicircular grooves 24 therein which cradle the wire 14. Attention is also directed to curved surfaces 26 on the forward or freeends of the jaws l8 and 22. The intermediate or central member 20 is in the form of a tongue havinga shank,

28 which is fairly resilient. It will also be observed that the tongue 20 has a sloping end 30. As best viewed in FIGS. 3 and 5, it will be discernedthat the sloping end 30 of the tongue 20 extends to an elevation somewhat lower than the upper portions of the curved ends 26 of the

jaws

18, 22, thereby forming a dog or latching portion at 31 (FIG. 5). The tongue 20 also projects beyond the curved ends 26 of the

jaws

18, 22.

Owing to the convergence or tapering configuration of the

ends

26 and 30, the wire 14 can simply-be forced Once inserted, the wire 14 is held captive by the three

members

18, 20 and 22. Obviously, if the wire 14 is to be intentionally withdrawn, one can simply force the tongue 20 upwardly with ones fingers and the wire 14 can be retracted past the thus raised dog 31. However, any inadvertent detachment by cattle is made most difficult, especially when the wire is charged, and therefore the wire 14 is secured gripped for all intents and purposes.

The vertical wall 16 functions as a face plate for the body 17. It will be noted that the body 17 comprises two

top panels

32 and 34, these panels inclining upwardly and rearwardly to form apeak or ridge 36 therebetween. The peak or ridge 36 is in alignment with the intermediate member or tongue 20. The

panels

32 and 34 also slope downwardly to either side from the peak 36. Extending downwardly from the edges thereof which are remote from the peak 36 are

side panels

38 and 40 which have their forward vertical edges generally aligned with the

jaws

18 and 22. The

side panels

38, 40 reside in vertical but rearwardly diverging planes. The body 18, formed by the

panels

32, 34, 38 and 40 has a hollow interior which is open at the bottom as best understood from FIGS. 4 and 5. The hollow interior has been given the reference numeral 42 in these figures.

The rear edges of the

panels

32, 34, 38 and 40 connect integrally with a rear wall 44 composed of two

panels

46 and 48 which angle outwardly and rearwadly from the rear end of the previously mentioned peak 36. It will be noted that the front panel 16 extends upwardly above the

top panels

32 and 34 and also extends past the

side panels

38 and 40 as well as slightly beneath the lower edges of the side panels 38, 40 (see the relation appearing in FIG. with respect to panel 40). Somewhat similarly, the

rear panels

46 and 48 extend above the

top panels

32, 34 and also beneath the

side panels

38, 40. It is important to recognize that any path that leakage current from the highly charged wire 14 might traverse is quite lengthy, being rather tortuous in view of the panel construction that has just been alluded to. While contributing to an effective nonconductive path, it will also be appreciated that the box-like configuration imparted to the body 17 renders it quite strong, the panels all coacting to form a highly rigid body 17.

A barrel 50 having threads 52 thereon extends rearwardly from the wall 44. From FIGS. 3 and 4, it can be seen that the barrel 50 has a vertically oriented slot 54. The forward end of the slot 54, this being the end thereof nearer the wall 44, tapers in the direction of the wall 44. The tapered wall portions or surfaces of the slot 54 have been labeled 54a and 54b. A nut 56 that need have only a single thread therein has diametrically projecting cars 58 which can be easily grasped by a person's hand when the nut 56 is to be tightened (or possibly loosened if the insulator is to be removed from the post 12). From FIGS. 3 and 4 it will be appreciated that a three-point clamping action is produced, this being at approximately 120 angularly spaced locations by reason of the taper or angularity given to the wall surfaces 54a and 54b of the slot 54.

While a fence post 12 having a relatively large diameter has been pictured, it will be appreciated that a smaller cross section post can readily be accommodated in the slot 54 owing to the angularity of the wall surfaces 54a and 54b. All that is required is that the nut 56 be advanced farther along the barrel 50 to engage a smaller cross section fence post.

Although the foregoing description is believed adequate to provide a full comprehension of the benefits to be derived when practicing our invention, nonetheless a brief review of what is involved might be of some additional help. Therefore, with the nut 56 eitherremoved from the barrel 50 or at least loosened sufficiently to enable the insulator 10 to be placed over the upper end of the post 12, the insulator 10 can be lowered to the proper elevation that is required. When the correct positioning is achieved, then the nut 56 is manually tightened to hold the insulator 10 in place. g

Although the wire 14 can be tightened or pulled taut after it is engaged and held by the

members

18, 20 and 22, it is advantageous to have an insulator that will re ceive a previously tightened wire. Therefore, assuming that the wire 14 has been pulled taut, then it need be only brought into juxtaposition with the curved surfaces 26 on the

jaws

18, 22 and the sloping surface 30 on the tongue 20. The notch 33 shown in FIG. 2 has already been alluded to and readily accommodatesall conventional wire sizes, including double-strand barbed wire. It is believed obvious that the

surfaces

26 and 30 enable a camming or flexing of the tongue 20 to take place, the sloping end 30 being forced upwardly by pressing thewire horizontally against the surfaces 26 of the more

rigid hooks

18, 22. The additional length imparted to the tongue 20 provides an overhang that enables the installer to readily effect the insertion, for he can initially raise the wire 14 somewhat so that it abuts the underside of the sloping end 30. Having done this, he then pushes the wire 14 inwardly to produce the aforesaid camming, the wire reactively riding over the curved surfaces 26 in the process.

When the tongue 20 has been flexed upwardly enough, the wire 14 simply snaps into place and the sloping end 30 springs back to its normal or wireretaining relationship. This wire-retaining relationship is such that the sloping end 30, more specifically the dog 31 thereon, functions as a detent which prevents any inadvertent detachment of the now held wire 14. Consequently, the wire 14 is held captive within the notches 24 of the

jaws

18 and 22. If for any reason, the wire 14 is to be released, the tongue 20 can be forced manually upwardly to raise the sloping surface 30 sufficiently so that the wire 14 can be withdrawn.

It might also be pointed out that the insulator 10, if not accurately positioned initially on the post 12, can be raised or lowered as circumstances require to obtain the proper elevation for the wire 14 without detaching the wire from the

jaws

18, 22 and the tongue 20. Loosening of the nut 56 is all that is needed.

It is very important to appreciate that the only metallic members are the posts 12 and the wire 14 which are not part of the insulator 10. The insulator 10 has no metallic parts as has been necessary in some of the prior art insulator arrangements with which we are acquainted. Consequently, there can never be any arcing from the wire 14 to a metallic part of the insulator 10 (for no metallic parts are employed). The only possible path is from the wire 14 to the post 12. However, an exceedingly lengthy and tortuous route must be traversed in order to provide any leakage or shorting. First, the current would have to flow from the wire over a portion or portions of the

members

18, 20, 22 to the vertical panel or face plate 16, then over the upper or lower edges (or the side edges) to the

various panels

32, 34, 38 and 40. After flowing over the full fore-to-aft dimension of these panels, there would still be an additional electric hurdle by reason of the wall 44 composed of the

panels

46 and 48. The current flow would have to be over the upper edge of the wall 44 (or down beneath the lower edge or past one of the side edges) in order to reach the barrel 50. Still further, it is necessary that the current flow over a curved'portion of the barrel before it reaches the post 12.

Not only do all of the panels provide an extremely long electrical path that must be followed, but the slope of these panels is such as to effectively shed any water that might otherwise collect and contribute to the shorting or leakage action. When it is appreciated that a large number of insulators are usually used in conjunction with an electrical fence, it becomes highly desirable that no individual insulator create a leakage path, for a number of leakage paths in parallel will provide an undue drain on the electrical charging system, which obviously is to be avoided if a high electrical potential is to be maintained between the wire 14 and ground; each fence post 12 being of metal is, of course, grounded.

Not only are the electrical insulating characteristics superb with our insulator 10, but for the compact size thereof it is exceptionally sturdy and rugged, thereby resisting breakage by virtue of any impact loads that our insulator might be subjected to. Therefore, the insulator is not only efficient but exceedingly long lasting as well. Still further, out insulator 10 can be held at any desired height on the fence post 12. Furthermore, the cross section of the fence post 12 is not critical because the barrel S0 is structured so as to accommodate a reasonable range of post diameters.

We claim:

1. An electric fence insulator comprising dielectric body means adapted to be attached to a fence post, a pair of integral dielectric hook-shaped jaw members projecting generally horizontally from said body means at one elevation for receiving a fence wire therein, the forward ends of said jaw members sloping in one direction, and an intermediate resilient tongue member of plastic material projecting horizontally from said body means at a different elevation from said jaw members for retaining said wire in said jaw members, the forward end of said tongue member sloping in an opposite direction to the one direction in which the forward ends of said jaw members slope to form a dog portion, said tongue member being vertically thinner between said dog portion and the end thereof connected to said body means.

2. An electric fence insulator in accordance with claim 1 in which said tongue member projects farther from said body'means than said jaw members.

3. An electric fence insulator in accordance with claim 1 in which said one elevation is below said different elevation and said jaw members are provided with horizontally aligned upwardly facing notches between said body means and their said sloping ends, said sloping ends sloping upwardly to form the upper edges of said upwardly facing notches, and the dog portion of said tongue member being horizontally aligned with said upper edges and said tongue member having an elongated shank curving upwardly to cause said tongue member to be vertically thinner between said dog portion and the end thereof connected to said body means,

thereby rendering said tongue member sufficiently resilient so that the sloping end of said tongue member which is normally at said different elevation can be cammed upwardly by the fence wire to permit the reception thereof in the notches of said jaw members.

4. An electric fence insulator in accordance with claim 1 in which said body means includes a vertical panel of plastic material having an upwardly projecting marginal portion, said tongue member being integral with said upwardly extending marginal portion, said jaw members projecting forwardly from said panel, said one elevation being lower than said different elevation. 5. An electric 'fence insulator in accordance with claim "4 in which said body means includesadditional panels extending rearwardly from said vertical panel.

6. An electric fence insulator in accordance with claim 5 in which said additional panels include a pair of top panels inclining upwardly and rearwardly from said vertical panel.

7. An electric fence insulator in accordance with claim 6 in which the adjacent edges of said top panels form a peak orridge'inclining rearwardly in a generally fore and aft alignment with said tongue member.

8. An electric fence insulator in accordance with claim 7 in which said additional panels further include a pair of said panels extending rearwardly from said vertical, panel. I i

9. An electric fence insulator in accordance with claim 8 in which saidside panels have their forward edges in general alignment with said pair of jaw members and their rear edges spaced farther apart to provide a pair of rearwardly diverging panels.

10. An electric fence insulator in accordance with claim 9 in which the upper'edges of said diverging side panels are joined to the edges of said top panels remote from said peak.

11. An electric fence insulator in accordance with claim 10 including a dielectric vertical rear-wall joined to the rear edges of said top panels and to the rear edges of said side panels, said rear wall extending above the rear edges of said top panels.

12. An electric fence insulator in accordance with claim 11 in which said vertical wall includes a pair of panels angling rearwardly from the rear end of said peak.

13. An electric fence insulator in accordance with claim 11 including a threaded barrel projecting rearwardly from said rear wall at an elevation beneath the upper edge of said rear wall, said barrel having a vertical slot therein for the accomodation of the fence post.

14. An electric fence insulator in accordance with claim 13 in which the forward end of said slot tapers toward said wall so that said rear wall is spaced forwardly from a fence post having a circular cross section.

15. An electric fence insulator in accordance with claim 14 including a nut threadedly carried on said barrel for engaging said post and pulling the tapered ends of said slot against said post.

16. An electric fence insulator of plastic material comprising a relatively thin vertical panel, integral body means extending rearwardly from the lower portion of the rear side of said vertical panel so as to provide said vertical panel with an upstanding marginal portion extending above said body'means, a resilient tongue member projecting forwardly from the front side of said marginal portion, and a pair of hook-shaped jaw members projecting forwardly from the lower portion of the front side of said vertical panel, said jaw members being substantially at the said elevation as the rearwardly projecting body means, said tongue member having a downwardly sloping surface extending from its foremost edge in the direction of said vertical panel and said jaw members having surfaces sloping upwardly toward said vertical panel to form a notch with the sloping surface on said tongue member so that a wire can be forced into said notch to cause said tongue member to be flexed upwardly.

17. An electric fence insulator in accordance with claim 16 in which the integrally connected end of said tongue member extends vertically throughout the height of said marginal portion, said tongue member curving upwardly away from said connected portion and then downwardly to form a downwardly facing notch, said tongue member having a dog portion between said downwardly facing notch and said downwardly sloping surface, and said jaw members having connected portions having a height corresponding to the height of said rearwardly projecting body means, said notches curving downwardly from the upper edge of the connected portion and then curving fowardly and upwardly to said upwardly sloping surfaces on the jaw members to provide upper edges which are in horizontal alignment with said dog portion and over which the wire rides when a wire causes said tongue member to be flexed upwardly, said upward flexing being caused by the wire camming against said dog portion.

Claims

2. An electric fence insulator in accordance with claim 1 in which said tongue member projects farther from said body means than said jaw members.

3. An electric fence insulator in accordance with claim 1 in which said one elevation is below said different elevation and said jaw members are provided with horizontally aligned upwardly facing notches between said body means and their said sloping ends, said sloping ends sloping upwardly to form the upper edges of said upwardly facing notches, and the dog portion of said tongue member being horizontally aligned with said upper edges and said tongue member having an elongated shank curving upwardly to cause said tongue member to be vertically thinner between said dog portion and the end thereof connected to said body means, thereby rendering said tongue member sufficiently resilient so that the sloping end of said tongue member which is normally at said different elevation can be cammed upwardly by the fence wire to permit the reception thereof in the notches of said jaw members.

4. An electric fence insulator in accordance with claim 1 in which said body means includes a vertical panel of plastic material having an upwardly projecting marginal portion, said tongue member being integral with said upwardly extending marginal portion, said jaw members projecting forwardly from said panel, said one elevation being lower than said different elevation.

5. An electric fence insulator in accordance with claim 4 in which said body means includes additional panels extending rearwardly from said vertical panel.

7. An electric fence insulator in accordance with claim 6 in which the adjacent edges of said top panels form a peak or ridge inclining rearwardly in a generally fore and aft alignment with said tongue member.

8. An electric fence insulator in accordance with claim 7 in which said additional panels further include a pair of said panels extending rearwardly from said vertical panel.

9. An electric fence insulator in accordance with claim 8 in which said side panels have their forward edges in general alignMent with said pair of jaw members and their rear edges spaced farther apart to provide a pair of rearwardly diverging panels.

10. An electric fence insulator in accordance with claim 9 in which the upper edges of said diverging side panels are joined to the edges of said top panels remote from said peak.

11. An electric fence insulator in accordance with claim 10 including a dielectric vertical rear wall joined to the rear edges of said top panels and to the rear edges of said side panels, said rear wall extending above the rear edges of said top panels.

16. An electric fence insulator of plastic material comprising a relatively thin vertical panel, integral body means extending rearwardly from the lower portion of the rear side of said vertical panel so as to provide said vertical panel with an upstanding marginal portion extending above said body means, a resilient tongue member projecting forwardly from the front side of said marginal portion, and a pair of hook-shaped jaw members projecting forwardly from the lower portion of the front side of said vertical panel, said jaw members being substantially at the said elevation as the rearwardly projecting body means, said tongue member having a downwardly sloping surface extending from its foremost edge in the direction of said vertical panel and said jaw members having surfaces sloping upwardly toward said vertical panel to form a notch with the sloping surface on said tongue member so that a wire can be forced into said notch to cause said tongue member to be flexed upwardly.