Specification forming part of Letters Patent No. 48,906, dated July 25, 1865.

To all whom it may concern:

Be it known that I, LOUIS A. CAUVET, of No. 75 1/2 New street, in the city, county, and State of New York, have invented a new and useful Improvement in Insulators for Telegraphic Wires; and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to make and rise the same, reference being had to the accompanying drawings, forming a part of this specification, in which -

Figure 1 represents two insulators constructed after my invention arranged in a horizontal position upon a telegraphic pole, one of said insulators being shown in section. Fig.2 shows another mode of arranging said insulators on a pole.

Similar letters of reference indicate like parts.

This invention consists in constructing glass insulator, for use on telegraph-poles in such a way as that they can be secured to the poles in any position without the use of metallic or other attachments.

A, Fig. 1, represents a pole erected to sustain a line of telegraph-wire.

B is a wooden rod, upon each end of which a screw-thread, e, is cut.

C is a collar left on the rod when it is turned out.

The post A is perforated near its top to receive the rod B, which is passed through it until the collar C abuts against the side of the post.

The roll is secured to tile post by weans of the nut D, which is tightened against that side of the post which is opposite to the collar.

The insulator J is made of glass molded to any suitable shape as to its exterior, but having always one or more grooves, f, formed on its circumference, to enable a conducting wire to be wound about it.

The base or broad part g of the insulator is here shown to be a plane surface near its edge, with a recess about its center. I propose also to form the base g, of a convex shape, instead of partly flat or plane and partly sunken. When it is made convex it will shed rain with more facility,

especially when my insulators are fixed vertically, as shown in Fig. 2, the lower ones having their bases turned upward.

My insulator is made of glass, molded according to the art of the glass-molder, with a hole partly through it in the line of its axis, a screw-thread being formed in said hole in the process of molding. I do not, here claim an improvement in the art of moulding glass; but tile subject of my invention in this application is in the insulator made as aforesaid.

The insulator having been molded to the desired form, with an internal screw-thread formed in all axial perforation, as above explained, it is screwed upon one of the ends of the rod B, where it is retained by means of the articulation of the screw-threads.

When the rod is passed through the pole, as shown in Fig. 1, two insulators can be secured in horizontal positions.

In cases where it is desired to sustain several wires upon the sane pole at nearly the same elevations, I secure a rod, B, at or near each end of a cross - bar, A', which is then to be bolted to the post A. :More than two bars B may, if desired, be secured upon the cross-bar A'.

My improvement in insulators enables me to affix and secure them upon bars and pins with the rise of their screw-threads alone, by means of which they are sustained upon telegraph-poles by simply screwing them upon threads formed upon such bars or pins, and thereby to avoid the use of cement and fastenings of metallic hooks or wire, wherewith insulators have hitherto been fastened to their bearing- pins.

Having thus described in y invention, I claim as new and desire to secure by Letters Patent -

Constructing glass insulators for telegraph wires with all internal screw-thread, and securing them thereby to the bearings, bars, or pins of telegraph-posts, substantially as above, set forth.