Improvements in Insulators for Electric Wires.
Year: 1891

page_text: Date of Application, 17th Jan., 1891-Accepted, 21st Mar., 1891
COMPLETE SPECIFICATION.
Improvements in Insulators for Electric Wires.
I, FRANK ATHERTON Ross, of Livingston, in the County of Park and State of
Montana, United States of America, Superintendent, Livington Electric Light
Company, do hereby declare the nature of this invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement :-
The object of my invention is to provide an insulator for electric wires, in which
the use of binding wires will be avoided and in which the conductor may be
securely clamped without injury to the insulation or the wire itself.
My invention consists in an insulator threaded internally to receive a supporting
pin and provided with a watershed at its lower end and at its upper end with a
screw-threaded transversely-slotted part for receiving the wire, the insulator at the
bottom of the transverse slot being concaved or corrugated to antagonize a screw
having a similar surface, and a screw adapted to the threaded portion of the
insulator for clamping the wire upon the corrugated surface of the insulator, all as
will be hereinafter more fully described.
Reference is to be had to the accompanying drawings, forming part of this
Specification, in which
Figure 1 is a vertical transverse section, taken on line a Figure 3, of my
improved insulator.
Figure 2 is a side elevation, shewing the internal construction in dotted lines.
Figure 3 is a plan view, with the screw-cap removed.
Figure 4 is a plan view of the completed insulator.
Figure 5 is a vertical transverse section of a modified form of the insulator,
taken on line y-y Figure 7.
Figure 6 is a side elevation, shewing the internal construction in dotted lines.
Figure 7 is a plan view of a modified form, and
Figure 8 is a plan view of the same, with the screw-cap removed.
Similar letters of reference indicate corresponding parts in all the figures.
In the form of insulator shewn in Figures 1 to 4 inclusive, the insulator body A
is provided with a central internally-threaded opening B for receiving an insulator
pin and with a watershed C both of which are of the usual description. The
upper end D of the insulator is of cylindrical form and is furnished with an
external thread a. In the top of the insulator is formed a conical cavity E and a
transverse slot F. The floor of the slot F is concave at the centre of its length
and provided with rounded projections near its ends. To the upper part of the
insulator is fitted an internally-threaded cap G which is provided with a conical
projection H adapted to extend downwardly into the conical cavity E of the upper
part of the insulator.
In the modification shewn in Figures 5 to 8 inclusive, the upper end of the
insulator is bored and threaded internally and a cap G₁ provided with a screw-
threaded extension H' is inserted in the top of the insulator. The lower end of
the extension H₁ is concaved to adapt it to the corrugated floor of the transverse
slot F. In other respects this insulator is like that already described.
The method of using my improved insulator is as follows;-In the form shewn in
Figures to 4 inclusive, the cap G being removed, the wire to be supported is
carried through the slot F and the said cap G is screwed down upon the insulator
top, bringing the conical projection H into contact with the wire between the
projections b, thus slightly bending the wire and giving it a hold upon the insulator,
without in any way injuring the insulation or the wire. The lower edges of the
cap G are corrugated, as indicated in dotted lines in Figure 1 and full lines in

page_text: Figure 2, the object being to bring the edges of the cap into contact with the wire
in such a way as to prevent the cap from unscrewing accidentally. In the modifi-
cation shewn in Figures 5 to 8 inclusive, the wire is held in place in the slot in the
insulator by the screw extension H' of the cap G' which clamps the wire upon the
corrugated floor of the slot in a manner similar to that already described.
The advantages of my improved insulator are that the tie wire commonly used
is dispensed with and the liability of cutting the insulation on the wire, and thus
causing a leakage of the current, is avoided. The insulation of the line is improved
and a more perfect shedding of water is secured by reason of the projection of
the cap over the whole of the insulator. Furthermore, by the use of my improved
insulator, the construction of the line is greatly facilitated.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what I
claim is:-
:-
1. In an insulator, the combination with the insulator body provided with a
transverse slot having a curved or corrugated floor, of a screw-cap fitted to the
insulator and adapted to clamp the wire in the slot, substantially as specified.
2. The combination, with the insulator body A provided with a screw-threaded
upper portion and a transverse slot having a curved or corrugated floor, of a screw-
cap fitted to the insulator body and adapted to clamp the wire in the insulator, the
said cap being furnished with corrugations around its edges for engagement with
the wire, substantially as specified.
F. A. ROSS.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.