To all whom it may concern:

Be it known that I, ROBERT G. BROWN, of Brooklyn, county of Kings, State of New York, and a citizen of the United States, have invented an Improved insulator for Telegraph and Analogous Line-Wires, of which the following is a full, clear, and exact description, reference being had to the accompanying drawing, forming part of this specification.

My invention relates to an insulator for telegraph and analogous line-wires, and it consists in an insulator having an opening extending centrally longitudinally entirely through it, and with the wall of the opening screw-threaded throughout its entire length, as hereinafter particularly set forth, whereby an insulator is constructed which is particularly adapted for use upon the under or lower side of a cross-arm or similar support.

In the drawing is shown a central longitudinal sectional view of an insulator containing my invention, the pin or support, to which it is especially adapted to be secured on the lower side of a cross-arm, being shown in broken lines.

A is the insulator, which is formed of glass or other non-conducting material.  The insulator is provided with the usual exterior or circumferential groove, a, for seating or attaching to the insulator the line-wire to be hung thereon.

At a' is an opening which extends centrally longitudinally of the insulator, and entirely through it from top to bottom.  The wall of this opening is screw-threaded throughout its length, as shown.

This insulator is especially adapted to be screwed upon a pin or support extending from the lower or under side of a cross-arm on a telegraph-pole or other such support, the pin entering the opening at the rounded or convex top a2 of the insulator, and engaging the thread on the wall of the opening.

The opening a' is desirably somewhat flaring from its lower end toward the top, so as to fit upon the sustaining pin, which is usually tapered at its threaded portion.

It is evident that when this insulator is screwed upon the downwardly projecting pin which is to sustain it upon the cross arm or support-- as, for instance, upon a telegraph pole-- any moisture, as from rain which may fall upon the rounded or convex top a2 will readily flow off, and that in case any moisture should find entrance into the opening a' about the pin its tendency will be to pass downward and flow out or escape through the bottom or lower end of the opening.

What I claim as my invention, and desire to secure by Letters Patent, is--

The described insulator for hanging line wires, having the convex or sloping top end, a2, and a central longitudinal opening, a', extending entirely through its body horn top to bottom and threaded throughout its extent, as and for the purpose specified.

ROBERT G. BROWN.

Witnesses:

A. S. FITCH,

A. G. VERMILYA.