IMPROVEMENTS IN THE MANUFACTURE OF TELEGRAPH CABLES.
Year: 1878

page_text: LETTERS PATENT to Edouard Berthoud, of Cortaillod, in the Canton of
Neuchâtel, in Switzerland, Manufacturer, and François Borel, of Boudry, in
the said Canton of Neuchâtel, in Switzerland, Engincer, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF TELEGRAPH CABLES.",
Sealed the 22nd April 1879, and dated the 29th October 1878.
PROVISIONAL SPECIFICATION left by the said Edouard Berthoud and.
François Borel at the Office of the Commissioners of Patents on the 29th
October 1878.
EDOUARD BERTHOUD, of Cortaillod, in the Canton of Neuchâtel, in Switzerland,
Manufacturer, and FRANÇOIS BOREL, of Boudry, in the said Canton of Neuchâtel,
in Switzerland, Engineer. "IMPROVEMENTS IN THE MANUFACTURE OF TELEGRAPH
CABLES."
This Invention relates to improvements in the manufacture of telegraph cables,
and has for object to apply the property of lengthening or drawing out possessed
by a heterogeneous ingot submitted to rolling or to drawing through the draw-
plate without changing quantities or relative positions of the different substances
of which it is composed, and to apply this property to the manufacture of telegraph
cables in which the insulation of the conductor is produced by means of substances
which were until now unemployed for this use.
For the manufacture of these cables a primitive ingot is prepared, the different
substances of which should be in order and quantities proportional to those of the
final cable to be obtained.
This cable must necessarily have for outer covering or envelope a hollow metal
cylinder, which protects the insulating material and the conductor, which are inside
the said cylinder.
The ingot thus prepared is rolled or drawn until it is reduced to the desired
diameter, which would take place when it be lengthened or drawn out to one
hundred times its original length.

page_text: The materials used to produce insulation can be fusible or in powder (if in
powder it must be rammed into the space between the conductor and the tube).
Amongst the former materials we may cite resin or colophony, sulphur, gumlac:
amongst the latter pulverized glass, pulverized silicious stones, asbestos, as-well-as
-the-mixtures-of these different substances.
These-cables can also be constructed in such manner as to obtain several con-
centric conductors. For this purpose we prepare a primitive ingot, made of several
metal tubes, placed one within the other, and separated one from the other by a
layer or coating of insulating material.-
These cables offer particular advantages for the phenomena of induction.
We reserve to ourselves the manufacture of cables formed of an outer envelope
or covering of soft metal, such as lead or tin, and having-as-conductor.copper, iron,
or other hard metal, the insulation of which would be produced by means of
melted or powdered materials, which could not be utilized without metallic tube
protector.
This manufacture is effected in the following manner:-As fast as the leaden
tube is made by the ordinary process, the conducting wire is introduced into the
empty space of the tube, and the insulating material in its liquid or powdered state
is introduced at the same time through lateral openings. If the insulating material
be in a liquid state the tube on leaving the machine in which it is made should
pass through a bath of cold water, so as to solidify the insulating material before
winding the cable on a drum.
These cables can also be made with several conductors by placing in the primitive
ingot several cylinders of the metal composing the conductor, and separated one
from the other by a layer or coating of insulating material, but in this case the
conductors being parallel they would suffer much when wound around a small
diameter.
A process of preservation consists in fixing at certain distances on the leaden
tube masses of iron or zine, which would produce with the lead an electric element,
and prevent oxidation of the latter.
The outer protective covering or envelope of these cables being of lead they are
very flexible, and they can be kept warehoused from any length of time.
When made of certain insulating materials they can be exposed to the rays of
the sun without injury; they can also be employed in field telegraphy and with
the telephone, which requires an excellent insulation of the conductor.
The metallic envelope or covering can be used as a return wire.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edouard Berthoud and François Borel in the Great Seal Patent
Office on the 25th April 1879.
EDOUARD BERTHOUD, of Cortaillod, in the Canton of Neuchâtel, in Switzerland,
Manufacturer, and FRANÇOIS BOREL, of Boudry, in the said Canton of Neuchâtel,
in Switzerland, Engineer. "IMPROVEMENTS IN THE MANUFACTURE OF TELEGRAPH
CABLES."
This Invention relates to improvements in the manufacture of telegraph cables,
and consists in applying the property possessed by a heterogeneous ingot submitted
to a rolling or to a drawing through the draw plate of being lengthened without
changing the quantities or relative positions of the different materials of which it
is composed, and in applying this property to the manufacture of telegraph cables,
in which the insulation of the conductor is produced by means of substances which
were, up to the present, impossible to be employed for this purpose.
For the manufacture of these cables we prepare a primitive ingot, the different
materials of which are in order and quantities proportional to those of the final
cable to be obtained.
These cables must necessarily have for outer envelope or covering a hollow metal
cylinder to protect the insulating material as well as the conductor, both of which
are inside thereof.
We will render this brief description more clear by giving the following example:
Suppose that a cable is to be manufactured having 8mm (about inch) outside
diameter, 1/m (about inch) thickness of metal forming the protective envelope
or covering, 2 (about inch) thickness of the insulating material, and the rest
2m (about 3 inch) for diameter of the conductor, then to obtain a telegraph
cable, as shewn on enlarged scale and in cross section, Figure 1, and having these
dimensions, it would be necessary to take an ingot having, for example, the
following dimensions:-
1st. The protective tube made of the chosen metal for the outer envelope or
covering should be 80mm (3's inches) outside diameter, with a thickness of 10m/m
(about inch).
2ndly. The cylinder of soft metal chosen for the conductor should have a diameter
of 20/ (about 18 inch); and
3rdly, and Lastly. The unoccupied space between the conductor and the pro-
tective tube should be filled by the insulating material selected, which if in powder
must be ramined in.
The ingot thus prepared is passed through a rolling mill or through a draw
plate until it be reduced to the fixed diameter of 8mm (about inch), which
would take place when it be lengthened to one hundred times its primitive
length.
The materials employed for insulation may be fusible or in powder. Amongst
the former materials we would cite resin or colophony, sulphur, and gumlac; and
amongst the latter pulverized glass, pulverized silicious stones, and asbestos, as well
as the mixtures of these different materials.
These cables may also be constructed in such manner as to obtain several con-
centric conductors, as seen in cross section at Figure 2. For this purpose a primi-
tive ingot is formed of several metal pipes or tubes placed one within the other,
and separated from each other by a layer or stratum of insulating material. These
cables offer particular advantages for the phenomena of induction.
We also manufacture cables composed of an outer envelope or covering of soft
metal, such as lead or tin, and having as conductor copper, iron, or any other hard
metal, the insulation of which would be effected by means of materials melted or
in powder, which could not be utilized without metallic protective tube.
This manufacture is effected in the following manner:-As fast as the leaden
tube is made by the usual processes (lead pipe press) the conducting wire is intro-

page_text: duced into the empty space of the tube by piercing a small central opening, and
the insulating material in its liquid or powdered state is introduced at the same
-time through lateral openings. If the insulating material be in a liquid state care
must be taken to pass the tube-coming-out-of-the-press or machine in which it is
-made-into-a bath of cold water, so as to solidify the insulating material before
-winding_the_cable on to a core or drum.
These cables can also be constructed with several conductors by placing in the
primative ingot several cylinders of metal which compose the conductor, and which
would be separated one from the other by a layer or stratum of insulating material,
but in this case the conductors being paralleled they would suffer much when
wound around a small diameter.
A process of preservation consists in fixing at certain distances on the leaden
tube masses of iron or zinc, which would produce with the lead an electric element,
and prevent oxidation of the lead.
The exterior protective envelope or covering of these cables being of lead they
are very flexible, and can be kept warehoused for any length of time.
Being made of certain insulating materials they can be exposed to the rays of the
sun without injury. They can also render great service in field telegraphy. They
can also be employed with the telephone, which requires an excellent insulation of
the conductor, an insulation which is very costly to obtain by means of the existing
gutta percha cables.
By having a metallic envelope or covering the same can always be used as
return wire, which is of great use in many cases.
When necessary we can envelope or cover these cables with suitable sheathings,
according to the circumstance in which they would be placed.
Having now described the nature of the said Invention, and in what manner the
same may be performed, we declare that we claim,―
First. A telegraph cable composed of a conducting wire, of an insulating envelope
or covering, and of a second protective envelope or covering in homogeneous metal,
substantially as herein described, the whole being able to compete advantageously
in respect of insulation with all telegraph cables now constructed, while being much
cheaper.
Second. The utilization of the property possessed by a heterogeneous ingot, of
being lengthened on being passed through a rolling mill or draw plate without
changing quantities or relative positions in the manufacture of telegraph cables
containing a conductor of soft metal, as set forth.
Third. The manufacture of telegraph cables containing several concentric con-
ductors according to the same system, substantially as herein described.
Fourth. The manufacture of telegraph cables, such as mentioned in the first
claim, and containing a conductor of hard metal by means of an ordinary press or
machine for making lead pipes or tubes by introducing the conducting wire and
the insulating-material into the homogeneous protective metal tube as fast as it is
made, the insulating material being either in powder or in fusion, substantially as
herein described.
In witness whereof, we, the said Edouard Berthoud and François Borel, have
hereunto set our hands and seals, this Eighteenth day of April, in the
year of our Lord One thousand eight hundred and seventy-nine.