IMPROVEMENTS IN THE MANUFACTURE OF CABLES FOR TELEGRAPHIC AND PROVISIONAL SPECIFICATION
Year: 1880

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, Engineer, for an Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF CABLES FOR TELEGRAPHIC AND
PROVISIONAL SPECIFICATION left by the said Edouard Berthoud and
François Borel at the Office of the Commissioners of Patents on the 6th
December 1880.
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 CABLES
FOR TELEGRAPHIC AND TELEPHONIC PURPOSES, AND IN APPARATUS EMPLOYED
THEREIN."
Our Invention has for its object improvements in the manufacture of cables for
telegraphic and telephonic purposes, such as described in the Specification of our
British Letters Patent, No. 4346, dated 29th October 1878, and means for such
manufacture.
The cables constructed according to this Invention have their various parts
so arranged and combined that all induction between the several conductors
forming one cable is obviated, and they can therefore be advantageously used for
telegraphic lines of great length and for telephonic purposes.
The principle on which this Invention is based is the following:-Given an
insulated wire, placed beside another wire, it is known that the moment a current
is established in one of the wires an instantaneous current of inverse direction is
produced in the adjacent wire. The moment the current is interrupted in the
first wire an instantaneous current is produced in the second one, which will be in
the same direction as was the current which had been interrupted in the first wire.
As these induced currents exist, whatever be the insulating material employed,
they can only be annulled by a special arrangement which would set up a second
induced current in the contrary direction and of the same intensity. Therefore
the most complete proceeding would consist in sending in an inverse direction a

page_text: current through the wire in which the transmitting current is passing. This
however being impossible as two currents of contrary directions and of the same
intensity cannot simultaneously exist in the same wire, we have solved the problem
in the following manner :-
Around the conductor we place a second conductor whose section is a regular
figure, annular, round, square, triangular, or the like, and in the centre of which is
the transmitting wire. Now if a positive current is caused to pass through the
central wire and the negative current through the hollow conductor surrounding
it, the effect of the induction produced by the current passing through the exterior
conductor is exactly the same as would be that produced by a current passing
through the centre of the figure. As this induced current is of the same intensity
as but of opposite direction to that of the central wire, it is evident that the new
current would completely neutralize the effect of the former.
To obtain this result in a perfect manner the resistance of both conductors must
be the same. Practically they would approach each other as much as possible.
Therefore to obtain this result in an economical manner we manufacture such
cables as follows:-
We take (as for ordinary telegraph cables) a conducting wire, usually of copper,
and cover the same with several layers of cotton. We immerse this wire in a bath
of insulating material raised to a high temperature in order to carry off the
dampness of the wire and to impregnate it with the insulating material, which
may be resin, tar, paraffine, or the like; we then cover it with a leaden sheathing
by means of the lead pipe press, such as used in accordance with Claim 4 of the
Specification of the Letters Patent herein before recited, or by any other suitable
press, such, for instance, as that hereinafter described, or with a strip or ribbon of
lend or other metal wound spirally around it, and we then cover the said leaden
sheathing with one or more layers of cotton or like material.
We next unite a suitable number of the conductors thus prepared and submit
them to a fresh bath, and we then protect the whole by means of a leaden pipe or
tube.
To render the cable more durable we in some cases employ the following 'mode
of manufacture :-
The cable prepared as hereinbefore specified is covered with a fresh sheathing
of lead, which is separated from the first one by a layer of gas tar or other
impermeable material introduced between said leaden sheathing as fast as the
cable is manufactured. Thus the vital parts of the cable are protected by a first
or interior leaden sheathing, covered with a layer of gas tar, maintained by
a second leaden sheathing which forms the second or exterior sheathing or
envelope.
A convenient apparatus, or lead pipe press, to be used in the manufacture of
these cables consists of a heated chamber or receptacle containing melted insulating
material, below which chamber is a ram or plunger worked by a hydraulic press
and causing the lead to flow into a tube or pipe around a suitably arranged
spindle or mandrel which forms the hollow of the tube. The copper conductor
surrounded by cotton, impregnated with insulating material as above stated,
passes through the said spindle or mandrel, which has a passage or way for this
purpose; this spindle at the same time allows passage to the insulating material in
the receptacle, so that the same fills the space between the conductor and the
interior walls of the leaden tube or pipe.
For the purpose of obviating the deviation to which the spindle or mandrel is
liable when attached in the manner hitherto in use, we firmly connect the same
with the ram or plunger above described, and provide a suitable number of arms
for ensuring a better working.

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 2nd June 1881.
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 CABLES
FOR TELEGRAPHIC AND TELEPHONIC PURPOSES, AND IN APPARATUS EMPLOYED
THEREIN.
"
The first part of our Invention relates to the manufacture of cables for telegraphic
and telephonic purposes, such as described in the Specification of our British Letters
Patent, No. 4346, dated 29 October 1878, and the second part thereof, to means or
apparatus to be employed for such manufacture.
The cables constructed according to this Invention have their various parts so
arranged and combined that all induction between the several conductors forming
one cable is obviated, and they can therefore be advantageously used for telegraphic
lines of great length and for telephonic purposes.
The principle upon which our Invention is based is the following:-Given an
insulated wire placed beside another wire, it is known that the moment a current
is established in one of the wires an instantaneous current of inverse direction is
produced in the adjacent wire. The moment the current is interrupted in the first
wire an instantaneous current is produced in the second one which will be in the
same direction, as was the current which had been interrupted in the first wire.
As these induced currents exist, whatever be the insulating material employed, they
can only be annulled by a special arrangement which would set up a second induced
current in the contrary direction and of the same intensity. Therefore the most
complete proceeding would consist in sending in an inverse direction a current
through the wire in which the transmitting current is passing. This however being
impossible, as two currents of contrary direction and of the same intensity cannot
simultaneously exist in the same wire, we have solved the problem in the following
manner:-
Around the conductor we place a second conductor whose section is a regular
figure, annular, round, square, triangular, or the like, and in the centre of which is
the transmitting wire. Now, if a positive current be caused to pass through the
central wire, and the negative current through the hollow conductor surrounding
it, the effect of the induction produced by the current passing through the exterior
conductor is exactly the same as would be that produced by a current passing
through the centre of the figure. As this induced current is of the same intensity
as but of opposite direction to that of the central wire, it is evident that the new
current would completely neutralize the effect of the former.
To obtain this result in a perfect manner, the resistance of both conductors must
be the same. Practically they would approach each other as much as possible.
Therefore to obtain this result in an economical manner, we manufacture such
cables as follows:-
We take as for ordinary telegraph cables or wires a conducting wire, usually of
copper, and cover the same with several layers of cotton. We immerse this wire
in a bath of insulating material raised to a high temperature in order to carry off
the dampness of the wire and to impregnate it with the insulating material, which
may be resin, tar, paraffine, or the like; we then cover it with a leaden sheathing
by means of the apparatus hereinafter described.
Or we cover the insulated wire with a strip or ribbon of lead or other metal
wound spirally around it, and we then cover the said leaden sheathing with one or
more layers of cotton or like material.

page_text: We next unite a suitable number of the conductors thus prepared, and submit
them to a fresh bath, and we then protect the whole by means of a leaden pipe or
tube.
To render this cable more durable we in some cases employ the following mode
of manufacture :-
-
The cable prepared as herein before specified is covered with a fresh sheathing
of lead, which is separated from the first one by a layer of gas tar or other
impermeable material introduced between said leaden sheathings as fast as this
latter is manufactured. Thus the vital parts of the cable are protected by a first
or interior leaden sheathing covered with a layer of gas tar maintained by a second
leaden sheathing which forms a second or exterior sheathing or envelope. The
cable thus arranged and combined is seen in transverse section in Fig. 1.
The second part of our Invention relates to a new or improved apparatus for
manufacturing the insulated cables for telegraphic and telephonic purposes herein-
before described.
In the accompanying Drawings Fig. 2 is a front elevation, partly in section, of
our new or improved apparatus; and Figs. 3 & 4 are detailed views in section
shewing the parts for forming the leaden envelope or sheathing.
A is a cylindrical chamber which is open at bottom, and adapted to receive a
centrally and longitudinally perforated block of lead; it is connected with the
cylinder of a hydraulic press B (but any other kind of press may be used as found
necessary) by means of the columns C, C. This press B contains a piston D.
Upon the top of the piston D a centrally and longitudinally perforated block F
is hinged, and is connected with a crosshead G situated above the chamber A by
means of rods H passing through such chamber. This crosshead G supports a
tube J, the lower end of which is provided with a die or punch I (seen in detailed
view, Fig. 3). The upper end of this tube J supports a tank K containing suitable
insulating material (paraffine by preference). This tank is surrounded by another
tank L containing hot oil or other suitable liquid, or hot air, to keep the insulating
material in a fluid or semi fluid condition. The oil tank L is also surrounded by a
tank M which contains charcoal or other nonconductor of heat to prevent the oil
from cooling. Or the tank L may be covered with nonconducting material in any
other suitable manner.
The oil, or other liquid or gas, is conducted into the tank L through the pipe N,
and passes thence through the pipe O into a jacket or annular chamber P
surrounding the chamber A, and from there is drawn off through the pipe Q.
R and R¹ are glass gauges, by means of which the quantity of liquid in the
tanks L and P can be ascertained. The tank P is also surrounded by some
nonconductor of heat contained in the jacket S.
The tank K is provided with a plug e or like contrivance for drawing off the
remaining insulating material when the operation ceases.
T is a threaded tube which is provided at its lower end with a cone d which
exactly fits into the top of the tube J, and at its upper end with a nut f. This
tube passes through the lid y of the tank K, and is supported thereon by the
nut f.
In order to remedy the evils resulting from the mode of attachment of the punch
or die I with the tube J as hitherto practised for forming the interior diameter of
the leaden envelope or sheathing covering these cables, the following improvements
seen in sectional elevation, Fig. 3, and in horizontal section, Fig. 4, has been
devised.
Instead of leaving the punch or die I free at the end of the tube J, which very
often under the influence of both heat and pressure causes a change of position of
such punch or die and occasions an inequality of thickness of the leaden envelope
or sheathing, the relative positions of the punch or die I and the matrix p are
adjusted, as described below, and thus we obviate all vertical and lateral
deviation.
J is an annular piece, which surrounds the punch or die J, and which is formed

page_text: with arms of any suitable number and shape. It is attached to the tube J, as
seen, but only lies in or is countersunk in the block F, which carries the matrix p;
the deviations to be prevented are therefore those of the tube J (into which is
screwed the die or punch I) and the matrix p (which is screwed into J*); it is thus
quite sufficient if J* and p be screwed together; the piece J* need not be otherwise
affixed to F.
As the block F carrying the matrix p must be rotated on its pivots when a fresh
block of lead is to be placed into the lead chamber A, a shelf h, supported on
brackets i, i, attached to the columns C, and a windlass V on the opposite two
columns, assist in raising this block. The block is shewn rotated in fragmentary
side elevation in Fig. 5.
Z is a pulley, which works in the slot W formed in the upper part of the piston D ;
Y is a pipe, which leads water or oil to the upper end of the piston of the press,
and Z is a pipe which leads the same to the lower end of said piston.
By simply passing the cables through the tank K and the tubes T and J they
may be, if desired, insulated without being covered with lead.
The working of the machine is as follows:-
A cylindrical centrally and longitudinally perforated block of lead is placed into
the lead chamber A, or the lead is melted in the same by means of an opening
formed in the top of the chamber, and the cable or wire, which must be previously
surrounded by a covering of cotton or other fibrous material, is passed through the
tubes T and J. If the tube T is slightly raised the insulating material will flow
through the space between the lower bevelled end of the tube T and the top of the
tube J, and as the cable is in the tube J the insulating material passes into and
around the cable, completely impregnating the same. The cable passes through the
block of lead, which is kept at a very high temperature by the hot oil, or water,
or air in the jacket P, so that all the moisture is removed from the fibrous covering
of the cable. If water is forced in the cylinder of the hydraulic press through the
pipe Z the piston will rise and press the top of the block F against the underside
of the block of lead in the lead chamber A, and the lead is forced to escape in the
shape of a leaden tube, the inside diameter of which is equal to the diameter of the
lower edge of the die or punch I, and the outer diameter of which is equal to the
diameter of the aperture in the matrix p through the central bore X of the block F,
but as the cable has been conducted into this bore by the tube J it is evident that
the so formed tube will snugly surround the cable.
As fast as the tube is produced it draws the cable downwards, which then passes
over the pulley 7 and is wound on to some suitable drum.
The bore X of the block F is greater in diameter than the inner diameter of the
tube J, so that the covered cable can conveniently pass through it. The die or
punch I and the matrix p may be changed for others, so that the thickness of the
leaden tube may be made as desired, and a cable of any desired diameter may be
passed through the tube J. As soon as the entire block of lead has been formed
into a tube, water or other liquid is admitted into the upper part of the cylinder of
the hydraulic press through the tube Y, and acting upon the shoulder of the piston
forces this piston downwards, a cock to let out the liquid below the piston having
been previously opened. The block F is then laid over on the shelf, as shewn in
Fig. 5, and a fresh block of lead is inserted into the lead chamber A.
The insulated cables manufactured by the herein described apparatus are more
perfectly insulated than any other kind of cable; the insulation is absolutely
perfect. The cable cannot be damaged by moisture; it can be conveniently
handled without damaging the insulating envelope, which can be made of any
desired thickness, and finally permits of using numerous materials for insulators
which could not be used for this purpose heretofore, and consequently the cost of
the cable is materially reduced.
Having thus described the nature of our said Invention, and the manner of
carrying same into effect, we declare that we claim,―
First. The manufacture of cables for telegraphic and telephonic purposes, in

page_text: which the conductors are so arranged that the effects of induction produced by one
conductor on the other are readily destroyed, substantially in the manner as herein
described.
Second. The employment of lead tubes of small diameter to form with the
copper wire which is passing through the same a complete electrical circuit, as herein
set forth.
Third. The arrangement of the annular piece J*, connecting together the tube J
and the matrix p in the block F, such piece being provided with arms of any
suitable number and shape for the purpose of preventing lateral and vertical
deviation and obviating any inequalities on the leaden sheathings or envelopes, as
described and substantially as shewn.
In witness whereof, we, the said Edouard Berthoud and François Borel, have
hereunto set our hands and seals, this Thirtieth day of May, in the year
One thousand eight hundred and eighty one.
Witness,
JULES ARMENGAUD, jeune,
EDOUARD BERTHOUD. (L.S.)
FRANÇOIS BOREL. (L.S.)
Of Paris, Boulevard de Strasbourg 23,
Civil Engineer.