IMPROVEMENTS IN .. TELEGRAPH CABLES AND OTHER ELECTRICAL CONDUCTORS."
Year: 1881

page_text: LETTERS PATENT to William Thomas Henley, of Plaistow, in the County
of Essex, Telegraph Engineer, for an Invention of "IMPROVEMENTS IN
.. TELEGRAPH CABLES AND OTHER ELECTRICAL CONDUCTORS."
PROVISIONAL SPECIFICATION left by the said William Thomas Henley at
the Office of the Commissioners of Patents on the 30th April 1881.
WILLIAM THOMAS HENLEY, of Plaistow, in the County of Essex, Telegraph
Engineer. "IMPROVEMENTS IN TELEGRAPH CABLES AND OTHER ELECTRICAL
CONDUCTORS."
According to this Invention I construct combined telephone conductors with
alternate copper and galvanized or tinned steel wires, so that the current in one
direction is conveyed by the steel wire, and the current in the opposite direction
completing the circuit by the copper wire. I thus add very materially to the
tensile strength of the cable, and at same time prevent its stretching, keeping
the copper wire from exposure to any undue strain, and rendering it at the same
time possible to suspend such conductors from. house to house or on poles with
safety for considerable distances; the copper and steel wires forming a complete
circuit prevents the induction from wire to wire interfering with the working of
the telephone. Complete metallic circuits were used for telegraphing before it was
discovered that the earth could be used for the return circuit, but in this present
Invention the steel wires serve the double purpose of conveying the return current
and of strengthening the conductor or cable.
In some cases I purpose using ropes or cables of a round form, such for instance
as shown in Figures 1, 2, and 3, where the wires are insulated separately, and
copper wires and steel wires laid up alternately in the form of a rope, Figure 1
showing a single row of wires, and Figures 2 and 3 a double row for telephonic
purposes; but in Figure 3 the steel wires are not insulated, but are used for the
return circuit in general of the copper wires.
Figures 4, 5, 6, and 7. show a further improvement in insulating the wires; in
these cases the wires are by means of rollers or dies enclosed in the insulating
material. In Figure 8 I have shown a band in which there is a wider interval
.

page_text: between each pair of wires for the purpose of further decreasing the induction
effects.
In constructing these belts of insulated wires I may make them of any number
from two, as shown in Figure 7, up to any reasonable number, so that the band bet
not too broad. Figure 4 shows ten copper conductors made up into one band
suitable for telegraphic purposes; and Figures 8 and 9, alternate copper and steel
wires made up into a band for telephonic purposes. I do not confine myself to any
particular kind of insulating material.
In Figure 9 a number of the flat insulated bands are shown superposed and
placed in an iron trough, and in a wooden trough at Figure 10; the latter
should be creosoted, and may have wooden or galvanized iron lid. As shown in
Figure 9, the bands are separated from each other by a layer of felt or other
suitable material, for still further reducing the effects of induction. This arrange-
ment of superposed bands offers great facility for finding any particular wire at
any point for repairing, as the bands may be named A, B, C, D, and so on, and the
wires numbered 1, 2, 3, 4, 5, and so on, reading, say, from left to right. The lid
may be taken off and the trough dropped away from the bands when the ground
is opened sufficiently to raise the trough a little. The lids of both troughs may
be secured by galvanized, wrought, or cast iron sockets, with top sliding in
grooves.
In the arrangement shown in Figure 10 for belts of wires for underground
telegraph wires in a wooden trough, the conductor is larger and the steel wires not
used, as the induction does not perceptibly affect the working of the telegraph
instruments, so that each wire may be part of a separate circuit, and the earth,
forming the return. The advantage here gained is that a great number of insulated
telegraph wires may be laid in one trough at a very moderate expense, while the
wires are readily known and distinguished from each other at any spot. I may
thus, for instance, place about 100 separately insulated wires in a space of about
2 inches square... Instead of wood or iron troughs I may use earthenware
troughs.
Figure 11 shows the belt with alternate copper and steel wires as laid together
and arranged for suspension in the air. The combined system of wires is here
shown covered over with hemp or other similar or suitable substance.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Thomas Henley in the Great Seal Patent Office on the
29th October 1881.
WILLIAM THOMAS HENLEY, of Plaistow, in the County of Essex, Telegraph,
Engineer. "IMPROVEMENTS IN TELEGRAPH CABLES AND OTHER ELECTRICAL
CONDUCTORS."
According to this Invention I construct combined conductors for telephonic,
telegraphic, and other purposes as hereinafter described, by which means I obtain
additional strength and security, and obviate the disturbing effects produced by
induction from wire to wire. I make the insulated wires with, any suitable
material, but prefer the "ozokerited" india rubber. I enclose the wires by means
of rollers or dies in the insulating material in pairs, or any further number, as
shewn by the accompanying Drawings. Figure 1 shows a single pair; Figure 2,
three pairs united, the spaces between each pair being greater than between the
wires of each pair; this is to prevent the induction when using the metallic circuit
for telephone purposes, as that is found to be much better than using the earth for
the return circuit, although there is nothing new in using the complete metallic
circuit, as that plan was used in telegraphy before the use of the earth for the
return circuit. The metallic circuit is found to reduce the effects of induction
considerably, but by my present improvements it will be diminished very much
more, and the distances capable of being worked very much increased, also the
tensile strength of the ropes, bands, and cables much increased. To obtain the
latter effect I make one wire of each pair of steel, by preference galvanized or zinc
coated; this should be as much larger than the copper wire in same circuit, as its
electrical resistance is greater, so that the electrical conductivity of the pair of
wires, steel and copper, should be as nearly as possible equal. Figure 1 of the
accompanying Drawings shews a pair of wires thus constructed; and Figure 3, a
band of wires similarly made, with wider intervals between each pair; and Figure 4
shews several such bands superposed, with tarred felt or other suitable material
between each layer to keep the wires a suitable distance apart to counteract the
inductive effects. These may be deposited in an iron or wood trough, or may be
made up into a combined belt to be suspended from point to point, or laid along
the roofs of houses. When laid underground in pipes or troughs, the wires may be
all copper, as shewn in Figures 5 and 6, as so much tensile strength is not required,
and for telegraph purposes the belts or bands may be made as shewn in Figure 7,
or a number combined in a trough, as in Figure 8, where one hundred wires are
shewn in a wooden trough covered with an iron lid, forming one hundred separato
telegraphic circuits, as the metallic circuit is not required for the telegraph, neither
does the induction interfere, as the telegraph instruments are not so sensitive as
the telephone. Figure 9 shews some of the twin circuits for the telephone laid up
spirally round a central steel strand covered with yarn, and each pair is kept farther
apart by an intervening tarred cord; Figure 10 shews the same with a second row
or layer of the wires kept a certain distance from the other by tarred hemp or
other suitable material. The whole is then covered with "compounded " tape or
braided hemp; this furnishes a very strong rope either for suspension or putting
into pipes. These insulated wires may be single instead of being made in pairs;
but for telephonic purposes each two wires should be separated by a space from the
next two wires, as here shewn. Figure 11 shews the wires of copper and steel
insulated, laid up in pairs round a central core of hemp or other suitable material.
In this case the insulated steel wires, whilst forming part of the circuit, give the
necessary tensile strength without the central steel strand; Figure 12 shews a

page_text: .
double row according to same plan; Figure 13 shews insulated wires laid up round
a central cord of suitable material, with insulated steel wires laid up spirally, also
with tarred cords of hemp or other suitable material to keep the steel wires from
injuring the cores. These cores and steel wires may be laid up in a double row, as
shewn. The steel wires will be found to give great strength to the rope for the
purposes of suspension or otherwise, and may be used for the return circuit,
especially for telegraph purposes.
Having now described the nature of the said Invention, and in what manner the
same is to be performed, I declare that I claim,—
First. The construction of combined double or multiple conductors for telephonic,
telegraph, electric light, or other purposes, in the form of bands or belts of insulating
material, in which the conducting wires are embedded, substantially as set forth.
Second. The arrangement of pairs of wires, with a greater space between cach
pair than between the wires of each pair to obviate the effects of induction when
used for telephones, the insulated wires being either constructed on the twin
system, as shewn, or single insulated wires, so long as the plan is adhered to of
having the wires of each pair nearer together than to any of the other wires. In
this arrangement the metallic circuit system is to be employed.
Thirdly: The construction of. ropes or bands of insulated wires, in which steel
wires, also insulated, are employed for the return circuit, such wires answering the
double purpose of conducting the current and giving tensile strength to the ropes
or bands, substantially as set forth.
Fourthly. The construction of ropes or bands constructed with insulated copper
wires and steel wires not insulated, the latter to be used both as conductors and to
give tensile strength, as set forth in the accompanying Specification..
In witness whereof, I, the said William Thomas Henley, have hereunto set
my hand and seal, this Twenty eighth day of October, in the year of our
Lord One thousand eight hundred and eighty one.