IMPROVEMENTS IN INSULATORS OR APPARATUS " FOR CARRYING OVER-HEAD ELECTRIC TELEGRAPH OR OTHER WIRES
Year: 1883

page_text: LETTERS PATENT to Joseph Slater Lewis of Birkenhead in the county of
Chester for an Invention of IMPROVEMENTS IN INSULATORS OR APPARATUS
"
FOR CARRYING OVER-HEAD ELECTRIC TELEGRAPH OR OTHER WIRES
PROVISIONAL SPECIFICATION left by the said Joseph Slater Lewis at the
Office of the Commissioners of Patents on the 26th April 1883.
JOSEPH SLATER. LEWIS of Birkenhead in the county of Chester
MENTS IN INSULATORS OR APPARATUS FOR CARRYING OVER-HEAD
TELEGRAPH OR OTHER WIRES
"
IMPROVE-
ELECTRIC
This invention has for its object the simplification of Telegraphic Insulators,
and making them more serviceable and convenient for repair and removal, and,
what is still more important, so that iron bolts with iron nuts, which in course of
time become iron bound and rust tight, shall be dispensed with; and so that
Insulators shall not crack or burst this expansion of the bolt from rust and
corrosion.
First (1) As regards Terminal Insulators, these have been mostly made hitherto
with a bolt through the centre to which the shackle straps have been attached
and the line wire looped round the groove formed between the two sheds, or
inverts of the insulator, and as patented by Sir Charles Tilston Bright in 1858'
No 2601-This latter arrangement prevents the cleansing action of rain, and large
metallic deposits from rust of the straps and bolts soon cover the Insulator, and
consequently the Insulating surface is considerably deteriorated. Besides the flat
straps serve to cause lodgements of snow. Now instead of the hole through the
centre of the Insulator being straight, or slightly cone-shaped, I make it with
rounded funnel shaped ends with a groove cut therein, in which the line-wire
rests, so as to prevent lateral away or friction, and I bring the line wire round
through it and form a vertical loop, and I attach the two shackle straps round the
horizontal centre. They are preferably of iron, round in cross section, and' are
formed so as to fit closely in the central groove. The functions of the two ends
facing the line wire, is effected either by a link or hook and eye arrangement.
The other ends of the shackles I prefer to form somewhat Z-shaped, and I insert
CDC11

page_text: them into a hole, or holes of dimensions just large enough to receive the said ends
in a horizontal plate, bolted to a support. The shackle or terminal insulator by
this means stands out horizontally of itself, and at the same time is as firmly
attached to its supporting plate, as if the ends had been in a hooked form. The
invert cap insulator when formed with an inner screw and fitted with an iron
bolt, which screws therein, is apt to burst in time it is alleged by the bolt rusting
tight in it. To obviate this I altogether prevent the damp getting in to rust the
bolt by making the screw thread on the upper end of the bolt sufficiently long to
allow an india rubber washer to be placed between an iron nut, or iron washer,
and the collar on the bolt, or its equivalent, hereafter described, and the Insulator.
The nut or Insulator is screwed down till it bulges out the India rubber sufficiently
to entirely close the space between it and the bolt, and it and the Insulator.
I prefer however to split the bolt into four segments, with 2 open saw-slots cut in
the centre at right angles. These can be filled with India Rubber, or other
yielding substance, but they may be left open. This cannot burst the Insulator,
as the rust only tends to close the slots, and the bolt readily adjusts itself to any
Binuosities or other defects which may have been caused in the manufacture of the
porcelain or earthenware screw inside the cup. I find that after some years it is
almost impossible to remove the nuts from the bolts, and consequently in taking
down or removing a fractured Insulator, or bolt, either the Insulator, the bolt, or
the arm, is often damaged by the workman, and considerable loss of time ensues.
I therefore prefer to do without nuts for attaching the Insulator bolt to the
telegraph arm or bracket altogether, except the nut that compresses the aforesaid
India rubber washer when used. In place of the present bolt, I use an ordinary
beaded bolt, with threads cut at. the opposite end to the head, for engaging the
threads formed in the porcelain; and when an India rubber or other yielding
washer is not used, then the bolt is split as here before described. This bolt ĭ
insert up the hole in the supporting arm, or bracket, till the head comes against
the wood, or iron. The bolt then receives a pedestal washer, or sleeve, of malleable
or other iron, glass, or earthenware, or an iron tube with a washer at each end, or
its equivalent. The insulator is then screwed down on the top of the pedestal
and the attachment to the supporting arm or bracket is firm and complete,
Though not so efficient, I place on the top of the end of the pedestal an India
rubber or other yielding washer, and then a nut, or iron washer, I then screw the
bolt tight into the Insulator until the India rubber is bulged out as herebefore
described, and the rust is prevented from reaching the threads of the bolts for the
purpose set forth herein. The Insulator can be of the ordinary type with an inner
screw, or that patented by me in 1882, N° 1017
To prevent the bolt becoming unscrewed by vibration, I use a long washer of
ordinary galvanized hoop iron. When the bolt is screwed home one end of the
washer is bent against one side of the head of the bolt, and the other is bent
against the supporting arm or bracket. Where the India rubber washer is
dispensed with, this arrangement is not necessary, as the bolt is made square
underneath the head. With drop, or suspended Insulators, I form the inverted
cup with an internal female screw, cut in the clay whilst in a plastic state. The
line wire is then engaged with an iron tongue piece, hooked at the lower end, and
with a male screw for screwing into the female screw. On turning the Insulator
round the tongue piece with the wire is drawn up into the cup of the Insulator,
and the said wire is consequently held tightly in position. This tongue piece can
have a solid collar, or pedestal washer, or sleeve, an India rubber washer to close
the internal chamber, so as to prevent the screw rusting, or the tongue piece can be
split for the same purpose as before mentioned-In order to prevent damage to the
edges of the earthenware, a round iron cap, or washer may be used, through which
the tongue piece is put and the line wire presses.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent and
of an Order of the Lord Chancellor filed by the said Joseph Slater Lewis in
the Great Seal Patent Office on the 7th November 1883.
JOSEPH SLATER LEWIS, of Birkenhead in the County of Chester, " IMPROVE-
MENTS IN INSULATORS OR APPARATUS FOR CARRYING OVER-HEAD ELECTRIC-
TELEGRAPH OR OTHER WIRES."
This invention has for its object the simplification of Telegraphic Insulators, and
making them more serviceable and convenient for repair and removal, and, what is
still more important, so that iron bolts with iron nuts, which in course of time
become iron-bound and rust-tight, shall as far as possible be dispensed with.
In terminal insulators, or in insulators at points where the line wire takes a
sharp turn, a different form of insulator is used. Hitherto a glass, porcelain, or
earthenware insulator similar to the one I have shown in the drawings has been
used, but the central hole has been made straight, with sharp square-edged ends
for a bolt to pass through, and the shackle straps carrying the insulator have been
attached by the said bolt, while the liue wire has been looped round the body of
the insulator in a groove formed between the two sheds or inverts, on the plan
patented in England in 1858 by Sir Charles T. Bright No. 2601. Now it has been
found that this arrangement is not cleanly, and that large deposits of rust from tbe
straps and bolt soon cover the insulator, and consequently the insulating surface is
considerably deteriorated. Besides this there is often great difficulty in unscrewing
the nut off the bolt, and the flat straps serve to cause lodgments of snow.
In the drawings, Fig. 1' is a sectional elevation, and Fig. 2 a sectional plan of
insulator and shackle as improved by me.
In these, A is the insulator. B line wire. C shackles. D stationary support fixed
to post or other stationary object by bolt through bolt hole G. It will be seen
that instead of the straight square-edged hole through the insulator there is a hole
with trumpet or rounded mouths-and in some cases I may make the entire hole
(in longitudinal section) of curved contour, the two curves at the end being joined
by a long flatter curve so as to make the hole lesser in diameter at the middle and
gradually increasing in diameter at each end; for nearly all purposes however the
section as shown is to be preferred. The line wire passes through this hole in a
vertical loop. The two ends of the shackle straps C are passed round the centre
and linked up by a metal ring or binding wire H. Insulating lips E E' above and
below the said shackle straps prevent electrical contact in rainy weather. The
shackles C are made as shown with ends bent to a double or Z-shaped contour, Bo
as to fit into the hole in the support D and bind fast in it. In erecting, the
support is placed somewhat obliquely to the pull on the wire, the shackle is placed
round and ringed or bound at H, the Z-shaped shackle ends are then inserted in
the hole I resting on the end of support D and placed in position; the wire is then
attached in a vertical loop, and the weight of insulator and wire locks the insulator
in position and prevents the Z-shaped ends of the shackle from rising and being
drawn out of their position.
The present form of line insulator support almost universal in England is a
double-ended bolt with two collars; one end is passed through the wooden telegraph
pole arm until the collar rests on the wood, and is fastened with a not and washer, the
other is screwed into the insulator with sometimes an india-rubber washer between
it and the insulator.
Now there are some serious defects in this arrangement; first, the nut is liable
to rust fast on the bolt, consequently when the insulator has to be taken off great
inconvenience is experienced and often considerable damage done and. time wasted

page_text: to release it; second, the bolt having two collars on and two screwed ends, is more
difficult and costly to make than an ordinary bolt with a head and one screwed
end such as I use.
This part of my invention is best described by the accompanying drawing,
Fig. 3, which is a sectional elevation of the device. In it A is the insulator
preferably of my patent screw head variety, patented in 1882 N° 1017. B is an
ordinary bolt preferably made square at the base of the shank, as shown or with
a feather to prevent it turning in its support, and also split into four segments at
the screwed end by two gaw grooves or slots coat right angles to each other and
extending to below the point at which the screw enters the female screw of the
insulator. D wooden arm. E pedestal or long washer of iron, earthenware, or
other suitable material. F rubber or other yielding washer, and G nut; either of
these or both can be dispensed with if desired.
The mode of installation is as follows. The bolt is pushed up through the
telegraph cross arm till the head comes against the under side. The pedestal E is
slipped over the bolt, the rubber or yielding ring F is then placed on and screwed
down by the nut G till it is squeezed out of shape, projecting beyond the nut or
washer to a slightly larger diameter than the hollow of the insulator. The
insulator is now forced down over the rubber ring and screwed onto the bolt B till
it comes down against the nut G.
The rubber ring keeps moisture from entering to corrode the bolt, should
however moisture enter, the splits in the bolt allow for the expansion of the bolt
owing to the rust; sometimes I omit the nut and cut out a part of the insulator at
the commencement of the screw thread, just big enough to hold about half the
substance of the rubber ring, as shown in dotted lines P in the drawing. The
insulator is then screwed home against the ring and pedestal, and the ring squeezed
as much as possible into this cavity. This forins a very good protection for the
bolt, as it, forces the rubbor into the part immediately around the bolt and is much
better than pressing the ring between two flat surfaces. The nut G serves several
purposes; first, it bulges out or squeezes the washer and holds it in place, so as to
shut out all air and damp from the screw; second, it screws down the bolt tight
onto the arm and thus makes it a firm rigid stud to screw the insulator onto,
whereas when there is no nut the operator has to hold both bolt and insulator in
screwing the latter up. In some cases I place a solid collar on the bolt in place of
this nut, and a nut in place of the bolt head. The bolt is then passed through the
pedestal and arm and screwed up.
I can also if desired form the insulator and pedestal in one and place the rubber
washer above the post arm.
°
To prevent the bolt becoming unscrewed by vibration, I use a long washer of
ordinary galvanized hoop iron. When the bolt is screwed home, one end of the
washer is bent against one side of the head of the bolt, and the other is bent
against the supporting arm or bracket. Where the india-rubber washer is dispensed
with this arrangement is not necessary as the bolt is made square underneath the
head.
Drop or suspended insulators I improve in the manner set forth in Fig. 4. I
form the inverted cup A with an internal female screw B cut in the clay whilst in
a plastic state. The line wire E is then engaged with an iron tongue-piece C
hooked at the lower end D and with a male screw for screwing into the female
screw C. On turning the insulator round, the tongue-piece with the line wire E
is drawn up into the cup of the insulator and the said wire is consequently held
tightly in position as shown. This tongue-piece can have a solid collar G or
pedestal washer or sleeve, and an india-rubber washer H to close the internal
chamber so as to prevent the screw rusting, or the tongue-piece can be split for the
same purpose as already described in the case of the bolts for holding ordinary line
pedestals. In order to prevent damage to the edges of the earthenware, a round
iron cap or washer may be used pressing against the lower edge of the cup under
which the line wire passes and through which the tongue piece is put.

page_text: In using my screw-formed insulator patented No 1017 of 1882, I make it not
only with the necessary conical expanding screw upon its exterior, but also with
an interior female screw the groove of which winds in the opposite direction to
that of the exterior screw, and is adapted to turn upon or receive the upper
extremity of a supporting pin provided with a corresponding screw thread. By
means of this improvement the insulator is secured to the pin by the same
movement that serves to attach the conductor. Thus considering the loop to have
been formed on the line wire, the end of the exterior screw to be inserted therein,
and the insulator itself to be placed over a pin by simply turning the insulator
bodily in the required direction, both attachments will be simultaneously made.
This method of attaching the insulator is especially applicable with my present
invention, but care must be taken that both screws are screwed home tight, and
for this purpose I prefer to screw the insulator on tight first of all, then unscrew it
the same number of turns or portions of turns as is required to screw the insulator
fast into the shackle, then screw both screws up together. If desired to give extra
leverage the insulators can be made with a six-sided or square part to screw
them by.
Having now described my invention, I claim as the new manufacture to be
protected under the Letters Patent :-
==
1st. The terminal insulators having a central vertical rounded bearing for the line
wire, and horizontal bearing for the shackle or attaching device, substantially as
described.
2nd. The shackle or attachment device for terminal insulators, substantially as
described.
3rd. The apparatus for carrying overhead wires, consisting of a plain bolt with
or without collar, an insulating or non-insulating pedestal, and an insulator
substantially as described, whether the bolt be solid or split, and whether the
pedestal and insulator be in one, two, or more separate pieces, substantially as and
for the purposes described.
4th. The following several separate parts of the insulating apparatus: (a) the bolt
with the split end, (b) the pedestal, and (c) the insulator with a part cut away as
shown in dotted lines at P, each substantially as and for the purposes described.
5th. The drop insulator with hooked tongue-piece so arranged that by a simple
screwing motion the line wire may be drawn up against the. insulator or other
abutment abutting thereon on each side of the tongue-piece, substantially as
described.
In witness whereof I the said Joseph Slater Lewis have hereunto set my
hand and seal this sixth day of November in the year of our Lord one thousand
eight hundred and eighty three.
J. DLATER LEWIS (L.S.)