US47141A - Improvement in insulators for telegraphs - Google Patents

Description

S. F. VAN CHOATE. Telegraph-WW6 lnsulatorr Patented Aprii 4, 1865.

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UNITED STATES PATENT OFFICE.

S. F. VAN OHOATE, OF NEW YORK, N. Y.

Specification forming part of Letters Patent No. 47,141 dated April 4, 1865.

To all whom it may concern:

Be it known that I, S. F. VAN GHOATE, of the city and State of New York, have invented an Insulator for Telegraphic Purposes; and I do hereby declare that the following, taken in connection with the drawings which accompany and form partof this specification, is a description of my invention sufficient to enable those skilled in the art to practice it.

The great difficulty experienced in transmittin g and receiving telegraphic signals through or by means of long stretches of wire or other conductors in rainy weather or in humid atmospheres arises, not from the fact that the electric fluid passes from the wire-conductor through the substance of the insulator-glass or bone rubber, but it is the fact that the electric current or fluid finds a path to the ground along the surface moisture or film of vapor or other conducting-matter which has condensed or settled upon the outer surfaces of the wire, glass, or bone rubber and the surfaces of the post or other suspending apparatus. This film may not be perceptible to the eye or to the touch, yet it may be sufficient to carry off a portion of the current. These escapes, as in the case of posts, form so many leaks of the current to the ground, and consequently returns of the same to the opposite pole of the battery, (this being the normal tendency of the electric fluid,) so that the supplying battery-force fails to reach the distant instrument with full vigor, or, in other words, fails to complete its circuit through the distant instrument, but turns back at these various escaping-points, forming the difficulty which telegraphers call a ground or return, whereby the distant effect desired to be produced upon the receiving apparatus does not take place. Many devices have been presented with a view to obviate this serious difficulty, and which heretofore has rendered telegraphing so uncertain during rainy or foggy weather. The following is my plan for obviating this difficulty, which is called Van Ohoates Insulator.

In the accompanying drawings, Figure 1 is a perspective view of myinsulator in the shape of a wooden pin-bracket, showing the under side and the cavity A formed in it. This wooden pin is turned out in a common lathe, and is nicely rounding on top, in order to turn the rain ofi'.

The peculiar-shaped cavity, with its angles or grooves, as shown at b b in Figs. 1 and 2, forms the principal feature of this invention. The hub-shaped barrel or cylinder 0 c, Fig. 2, of the cavity-plate is veryimportant. It serves for two purposes. It closes up the large cavity A, so as to prevent the moisture from set tlin g or condensing in the chamber, while the lower projection or lip, (Z (1, forms a drip to prevent the rain from running into the cavityspace. The drawing is made upside down. When the insulator is secured to the post or other support the hook hangs underneath, so as to hold the wire. The cavity-plate is beveled on its outer under edge, and fits tightly in the groove cut into the wood, and is secured in its place by means of two small brads or nails, as at c c.

The object of the peculiar-shaped cavity A and the plate D is that when the whole are combined a dry space is secured between the hook and the outer surfaces of the wooden pin. This dry space prevents the electric current from escaping from the wire to the ground by means of any dampness which might be settled or formed upon the outer surfaces of the wire, hook, bracket, or post. The open space around the stem or neck of the hook at ff,

Fig. 2, is so small, and by means of the cylinder shape of the hub of the plate D the moisture would have to follow up this small space a considerable distance before it could spread on the roof of the cavity around the base of the hook.

The object of the second groove, 1) b, or indentation at the angle of the cavity is to give corners and jambs at various angles to prevent the dampness or moisture from spreading should it get inside of the cavity, while the lower projection of the cylinder of the plate forms a drip to prevent the rain or other water from running into or closing up the open= ing around the neck of the suspending-hook.

Fig. 5 shows a plate with an outer rim or drip, as at g g, which is a double protection against the rain. running into the hollow around the hook.

In order to protect the surfaces of the woo den bracket, as well as the plate and hook, and to prevent the surfaces of the metal from oxidating or absorbing moisture, and also in order to keep insects out of the cavity, particularly to prevent spiders from building their webs inside the cavity or on the bracket or hook, I

coat them over, inside and out, with a composition whose principal base is asphaltum, and whose principal solvent is naphtha. This composition forms a black varnish or paint, which makes the surfaces of the wood and iron impervious to moisture and protects the former from oxidation, while it renders the latter imperishable in the air.

What I claim is- 1. The combination of the cavity A, face-

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