May 1, 1883   

#276,839 by Joseph S. Lewis

Dec.25, 1883   

#290,922 by Frank L. Pope

Jan. 1, 1884   

#291,072 by Edward J. Murphy

Oct. 7, 1884   

#306,146 by Lawrence Gray

Oct. 7, 1884   

#306,147 by Lawrence Gray/Joseph Ham

The National Self-Binding Insulator.
   This insulator, which is coming into particular favor with telephone and telegraph people, is now controlled in the United States by Messrs. Lytle & Co., of this City. The American Bell Telephone Company have decided to adopt them for their long line work, and other local companies are using them with very satisfactory results. This Insulator is the invention of J. Slater Lewis, of England. and is being extensively used in Europe. It dispenses entirety with the old and troublesome tie-wire, being so constructed that the line-wire is applied and secured without the use of any tools whatever, and in the shortest possible time. It can be used in any situation, whether on curves, against walls, under bridges. on roofs or wherever a tie-wire can he used. It is remarkably simple, durable and efficient, and may be removed or renewed with the greatest facility. It is constructed with a conical and expanding screw-thread upon the exterior of the upper portion, similar in form and principle to the point of a gimlet. 

The line-wire is attached by means of a rigid wire shackle or clip, formed is the shape of a horseshoe. the curved portion of which is adapted to encircle the body of the insulator at the base of the conical screw portion, while each end of the clip is made into a hook adapted to grasp the line-wire. The bell of the insulator below the point of support of the line is given the form shown by experience to be the best.

Besides the peculiar form of attachment for the wire, the National Insulator is provided with a perfect internal screw. It is formed by newly-invented molding tools of peculiar form; the greater sharpness and accuracy of the thread gives a better hold to the pin, and facilitates the operation of securing the insulator both to the main line and to the support.

The figures 1 and 2 show the position of the clip and line-wire when applied to the insulator. 

The insulator having been screwed on the bracket or pin, give it three complete turns backwards after it has come to its bearing, and hook the clip on the line wire with the ends of the hooks turned upwards, as shown In Fig. 3, then drop the clip and line wire over the top of the insulator as shown In the same figure, after which the insulator must be screwed down on the pin as shown in Fig. 4. Care must be taken to see that the clip goes down the thread of the screw first with the line wire following it, the screwing motion being continued until the insulator comes to its bearing on the pin or bracket, when the attachment will be complete.

It will be seen that the insulator is secured to the pin or bracket, as well as to the line wire, by a single operation. In detaching the line wire this process is exactly reversed, the insulator is turned the other way, the line wire going up by the groove first and the clip following. Some linemen prefer to carry a pocket oil can, and before screwing on the clip they apply a single drop to the point oh the clip, and also on the line wire which rubs against the Insulator; friction is thereby avoided and the work made easier.

To replace a broken or damaged insulator of the common kind, it must be smashed and the pieces taken out. leaving the tie-wire attached to the line as shown in Fig. 5. The new insulator is then screwed on the pin or bracket as before, and the loop placed over the top of it, after which the operation is precisely the same as illustrated in Figs. 3 and 4. After a little practice the attachment may be made with great rapidity.

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In Mr. Duxbury's office I met Mr. Lytle, who was down from Boston on business. He tells me that work on the new insulators at Haverhill is progressing favorably; that the tools for making the new English (Lewis) "screw top" insulators are about ready, ant that they expect to turn out a big lot soon. By the way, a funny thing. Insulators is England are made of earthenware, glazed. They "come high" over there -- not far from sixteen cents each. They are made in a lathe, fired, then glazed, then fired again and are such handsome pieces of pottery that one wonders they are not put up in velvet-lined cases like Sevres cups. Why are they made of earthenware? Because in England, you know, we always use iron pins -- not the wooden things you stick up in this country, don't you see? Now, if we put on glass, the sun shines through it and don't heat it. but it does heat the iron, you know,  expands it, and cracks the glass. But if we use earthenware; don't you see, the sun can't do it. you know. Poor things, it never occurred to them to use opague glass; simply because they never had used opaque glass; but I am of the opinion that when Mr. Lytle gets over there with a few thousand screw-top insulators, made in one motion with a perfect inside thread, and of a beautiful white glass that the sun can't shine through, any more than it can through a piece of iron, and offers them at less than one-half what it costs the  manufacturers over there to turn out their hand-made ceramic specimens, the folks will wake up to the idea that "those blasted Yankees'.' still have an idea or two that they have not as yet had any conception of. By the way, Mr. Duxbury tells me that he has tried some of the new insulators of the "pony" size, and likes them very much indeed.

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