US2304204A - Electrical insulator - Google Patents

Description

Dec. 8, 1942.

ELECTRICAL INSULATOR` Filed June 13. 1941 ATTORNEY B. B. RATZMAN 2,304,204 y ductors Patented Dec. 8, 1942 UNITED STATES l'ATlEIlNlT.OFFICEi ELECTRICAL INSULATOR Borah B. Ratzman, Buttzville, N. J. Application June 13, 1941, Serial No. 397,833

3 Claims.

This invention relates to an insulator of the knob type for supporting electrical wire con- It is especially applicable for use in installations of electrical Wire fences where the practice now is to use barbed wire, even though the wire is electrified by a suitable current which has a sting to it when touched by an animal within the fence enclosure.

The usual practice in setting up electrically charged Wire fences is to use a knob type of insulator having an external circular groove near one end of the insulator and to hold the barbed wire in the groove by a suitable tie-wire. Unless one of the barbs, which are usually spaced several inches apart, comes immediately adjacent the insulator and the tie-Wire, no pull strain is applied to the stake to which the insulator is fastened, and several stakes may be missed by the barbs in this manner, thereby allowing an undue amount of sag in the fence wire and transmitting more strain to some stakes than to others,

I have found, from experience, that barbs are not necessary in an electrical fence for the reason that the moment an animal touches the electried Wire, it immediately backs away from it. By way of illustration, I had a cow that would leap over a four or five-foot fence as easily as a deer and no ordinary fences would keep her within bounds. As soon as I installed an electric fence and the cow came in contact with it, she forgot her fence-jumping propensites and kept a proper distance from the Wire. The use of a plain, bare Wire materially reduces the first cost of building the fence, as Well as increases the speed with which the fence may be put up and removes the danger to the fence builder of getting scratched by the barbs. In certain localities, the position of the fences is changed quite frequently to give different pasturage, and

the use of the plain wire and the insulator to be' described herein materially cheapens not only the first cost, but the cost of installing and setting up and changing the fence. Furthermore, by using my insulator, the strain due to the Wire is substantially evenly distributed ony each post. In other words, each post does its share of sustaining the wire It is therefore the principal object of my invention to provide an insulator which will allow al1 the advantages just pointed out to be attained.

Other and ancillary objects will be discerned from a reading of the following specification,

taken in connection with the drawing, wherein: 65

Figure 1 is a plan view looking down on a section of an electrical fence utilizing my insulator.

Figure 2 is a side elevation of Figure 1.

Figure 3 is a sectional View through the insulator and part of the post or support carrying it, showing one method of attaching the insulator to the support.

Figure 4 is a View on the line 4--4 of Figure 3.

Figure 5 is a view on the line 5-5 of the sliding bar member shown in Figure 4, but with the side of the bar in reverse position.

Figure 6 is a view similar to Figure 3 but showing a modified form of attaching the insulator to its support, Y l

Figure 7 is a View similar to Figure 3, but showing a still further modified form of attaching the insulator to a support.

Figure 8 shows the use of the insulator in the general application for supporting an electrical conductor for any purpose Where the knob type of insulator may be used.

In the various views wherein like numbers refer to corresponding parts, I illustrates supports to which is attached my improved form of insulator 2 by any one of the methods shown in Figures 3, 6 and '7. In Figure 3, the free end 3 of the irsulator, or that end away from the support, has a dovetail cross-channel 4 which is open at the end of the body portion of the insulator 2. The bottom of the channel 4 has an angular groove 5 therein to receive part of a wire conductor 6. The body 2 has a centrally located counter-bore 1 therein to receive the head 8 of a nail 9 which is driven into the support I by a punch placed in engagement with the head 8. Preferably a Washer IIJ is used under the head 8 of the nail, the washer I0 being preferably of some compressible material such as fibre. r'Ihe body 2 of the insulator can be made of any suitable insulating material such as lime glass, boro-silicate glass, porcelain or any other suitable insulating material, but for fence purposes I prefer to use lime glass as it will stand considerable abuse.

Fitting in the dovetail channel 4, is a slidable bar II which has tapered sides to fit closely within the dovetail channel. The inner face of the bar II has a groove I2 to` receive a part of the rwire 6. The groove I2 is preferably tapered along its length and breadth as illustrated in Figures 4 and 5 so that as' the bar II is forced into the channel 4, it will continuously increase its grip on the wire. The length of the bar II, as shown in the drawing, is approximately the same as the diameter of the knob 2 which is shown to be circular, although it may have a different shape. The bar II may, however, be longer than the diameter of the body of the insulator 2, in which case it is more readily moved to releasing position by taps on the advancing end of the bar which projects beyond the contour of the body 2I As shown in Figure 6, the insulator 2 has a depression I3 in the side to receive the nail 9 for fastening it to the support I.

In Figure '7 a screw I4, having a square shank I5 and head I6, is molded directly into the insulator 2 so that the same may be attached to the support I by screwing it directly thereto, but in all cases the wire may be attached to the body 2 of the insulator without disturbing the fastening means to its support.

In Figures 3 and 6 I have shown the bar II as of insulating material, but it may be of some suitable metal, as illustrated in Figure 7, such as Zamak which is a composition of zinc and aluminum and will not rust. Furthermore, while I have shown bare wire in connection with the insulator, the insulator is adaptable for use in Stringing insulated conductors as usually used in household wiring and other places, in which case the bar I I would preferably be made of insulating material.

While certain of the details of the body of the insulator and the sliding bar may be varied, these variations are believed to come within the scope of the appended claims.

What I claim is:

l. An electrical insulator for a wire conducto-1' comprising a body member of suitable insulating material and having a transverse channel opening in one end, the sides of the channel being tapered for a substantial distance to provide a large gripping surface with the narrow part at the end surface of the said body, the bottom of the channel having a tapered groove therein to receive a part of the diameter of the wire, a slidable locking bar having tapered sides to t substantially the entire tapered sides in the body in interlocking relationship and a tapered groove in the inner face of the bar to receive a part of the diameter of the wire, the small end of the taper being at the channelentering end oi the locking bar whereby when the slide is forced into locking position in the channel, the wire is securely clamped in a continuously increasing grip to the insulator, and means in the body for fastening the insulator to a support.

2. An insulator for a wire conductor comprising a body portion having means for attaching it to a support and means for attaching and detaching a conductor laterally to the body without disturbing the mounting of the body on the support, said last-mentioned means comprising a dovetail-shaped cross-channel in the end of the insulator and a slidable bar to snugly t the dovetail channel, the bar and bottom of the channel having cooperative grooves to continuously increase the grip around the wire when the bar is forced into locking position and to free the wire when the bar is forced out of the channel.

3. An insulator for a wire conductor having means for mounting it on a support and also having means for making an easy and quick attachment of the wire to the insulator, said secondmentioned means comprising a dovetail crosschannel opening in the free end of the insulator with a groove in the bottom of the channel to position the wire when passed lat rally through the open side of the channel, and a slidable bar to iit within the channel in full engagement with the side walls thereof, providing a secure interlock and having a groove in its inner face to increasingly grip the wire in cooperation with the channel groove as the bar is forced within the channel.

BORAH B. RATZMAN.

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