Improvements in or relating to Electric Cables.
Year: 1892

page_text: Date of Application, 13th Dec., 1892
Complete Specification Left, 17th June, 1893-Accepted, 12th Aug., 1893
PROVISIONAL SPECIFICATION.
Improvements in or relating to Electric Cables.
I, SEBASTIAN ZIANI DE FERRANTI of Charter House Square, London, E.C.,
in the County of Middlesex, Electrician, do hereby declare the nature of this
invention to be as follows:-
My invention consists of improvements in electric conductors where more than a
single conductor is formed into the same cable.
It most commonly applies to cables made up of two conductors for the ordinary
system of distribution of electric energy, and to cables made up of three conductors
used for what is commonly known as the three wire system, but of course the
invention is applicable to cables formed of more than three conductors.
My invention refers both to cables in which the conductors are rigid and are
contained within a rigid protecting tube of iron or other metal, and also to cables
which are flexible and which may be coiled on a drum so that they can be
manufactured in fairly long lengths, according to ordinary well known practice.
To form a cable of my rigid conductors, I prefer to make the conductors of
segmental pieces of copper of such a size that, when they are insulated and laid
together, the combination forms a circle. I am aware that copper of the above
section has been used to form rigid electrical cables. In my invention, however, I
make the conductors 20 or 30 feet in length, and wind each one with paper or
other insulating fabric the full length of the conductor, wound upon itself a number
of times until the requisite thickness is obtained. The paper, for instance, can be
of ordinary five feet width and cut in lengths equal to that of the cable, and
throughout this Specification the word " paper must be read to include any
flexible sheet tough insulating material.
I immerse this paper in oil, earth, wax or other suitable insulator, in order to
render it a better insulator, and preferably wind it on to the conductor hot, keeping
the conductor and insulation in a liquid insulating bath.
When the two conductors are placed together and with their insulation form a
circle, 1 prefer to roll them round with a further number of layers of paper, as
above explained. They are then drawn into an iron tube which is either drawn
down upon them by passing through a drawbench, or else wax or some insulator
which sets firm is forced in to hold them in position.
Where three conductors are to be used to form a single rigid cable, I may make
them in several different forms.
According to one method, I take a rod of copper of the desired section, and from
20 to 30 feet long. I roll this with paper as above explained. Upon this I lay
two semi-circular pieces of copper, but which are of such dimensions that, when
they are laid upon the insulation of the first conductor, they have a small clearance
between their respective edges. This clearance or space I fill with jute or some
vegetable fibre or other suitable insulator. The combination then forms a circle,
and this circle of copper and insulation I wind preferably with a number of layers
ol paper treated as above explained. This may be placed in a wrought iron or
other suitable protecting tube.
Another method by which I carry out this part of my invention is to have two
segmental conductors and one flat one between them: all of which, when wound
with a small thickness of insulation, as above explained, will form themselves, when
put together, in the form of a circle, which circle I may wind with more paper and
protect as above explained.
Another method of carrying out my invention is to have three segmental

page_text: conductors, each of which occupies nearly one-third of the circle, and which, when
each one is separately wound with paper and the three are laid together, form
approximately a circle, and which may be treated with more layers of paper or
insulating material and protected as above explained.
The last named arrangement may be advantageously constructed as follows:-
I may take the three segmental pieces of copper and lay them together to form
a circle with cut strips of paper laid in between each, so that two of these pieces
come between each conductor, the edges of the paper standing out to a considerable
distance. I may then spread out this paper by means of suitable apparatus, such
as drawing through a die or mould, so that laps round the outside of the
segmental conductors and so protects them. may even arrange it in such a
manner that the sheets overlap so that there may be no butt joint. I may then
take the conductors so insulated and wrap them with paper and protect them in a
metal tube, as above explained.
I
Where there are more than three conductors, I prefer to make the separate
conductors in the form of segments of a circle. In some cases, it is desirable to
start the basis of the cable in the form of a circular conductor of the necessary
section insulated by wrapping with paper. The separate segmental conductors
round about it are then separately wrapped with paper placed round about the
central conductor, and the whole is then wrapped and protected as above explained.
I vary the arrangement in the following manner, when it is desirable that the
conductor shall be of the flexible type:
:-
Where 1 desire to use two conductors to form one cable, I may lay up wires to
form two nearly semi-circular sections of copper. These wires I hold in position
during manufacture by passing through a die, and I twist them together with
insulation between their flat opposing surfaces, so as to form an approximately
circular body. These may be insulated on the outside with a paper wrapping, or
in any other suitable way, and may be then finished with a lead pipe for purposes
of protection.
. By one method, I make the insulating diaphragm between the two conductors of
paper and of sufficient width that the edges of the paper sticking out on each side
of the conductors may be turned over so as to wrap round the sides of the
conductors, and so, insulate them, as explained in relation to the solid conductors.
According to another method, I do not form the conductors simply of a bundle
of wires arranged to form a segment of a circle, but I form them either of a bundle
or strands of wires, and then, by means of either drawing through dies or rollers or
compressing into a mould, forming them into a laminated conductor, but which is
segmental in section and contains nearly the same weight of copper as a rigid bar
of the same external section. These I twist together and insulate as above
described.
According to another method, I make up these segmental conductors out of a
number of approximately radial sided segmental pieces, which, when put together,
form the necessary segmental shape, so that, when separated by insulation, they form
a circle. By this means, conductors of segmental form are obtained, which contain
practically as much copper as solid conductors, and yet which are flexible. These,
if desired, can be separated by sheets of paper, two between each strand, and
projecting out beyond the circumference; they are then twisted together and rolled
to a circular shape at the same time and the extra paper flaps rolled over them.
The object of making them of this form is so that each conductor should present a
portion of its surface to the outside circle to facilitate soldering on connections
which should make contact over every part of the conductors as a whole. The
insulation may be carried out according to any of the methods above described.
These opposing conductors may be twisted together with insulation, as above
explained, to form a fairly flexible cable.
carry out this part of my invention in another way by forming my segmental
conductors by wires of square or other shaped section, which, when put together,
form approximately half a circle. These pass through dies to lay them up together

page_text: in their respective positions. They may then be twisted together and treated
generally as above described.
Where three conductors are required to form a single flexible cable, I prefer to
make my first conductor of stranded copper of circular section. I wrap this with
insulating paper. Around this I strand a number of separate wires of segmental
section, half of which touch each other to form one conductor and the other half of
which touch each other to form the remaining third conductor. In between the
segments thus formed round the circle, I strand jute or vegetable fibre or other
insulating material to keep them apart, and to make them up a complete circle.
This circle of copper and insulation, I then wrap round separately with paper,
which is afterwards impregnated with oil, wax, or other insulating material, either
before the process of manufacture, in stages during the manufacture, or after the
whole of the insulating material has been applied, and the cable made up save and
except its protecting lead sheath.
In place of making the cable entirely as above described, I may make the two
conductors, which form nearly semi-circular layers of copper round the insulation
of the first conductor, of wires simply stranded round with the jute or other
fibre, separating them in two places to form two separate conductors, as above
described.
According to another method, I bunch three sets of conductors, each set to form
nearly the third of a circle, but which, when stranded up together with insulation
in between them, form three separate spiral conductors of approximately circular
section as a whole. These may be insulated as above described for solid conductors,
or may be separated in the same way and finished with a spiral wrapping of paper
and a tube of lead.
This may be slightly modified by obtaining the above sections by drawing the
above mentioned conductors through a die or rollers or pressing them in moulds, as
before, before they are twisted up to form a circle, so that they may form a more
definite section and more copper may be got into the space, or the twisting and
rolling can be accomplished simultaneously.
I may obtain three conductors in one cable, cach one of the sections described
above, by taking a larger number of segmental shaped conductors, several of which
are laid together to make up each separately insulated conductor, and these
conductors may be twisted together with their insulation, and dealt with as above
described.
According to another method, where I wish to make a cable of three conductors,
I make two of them as already described of nearly semi-circular section, and the
third one a flat strip in between. These sections may be made up of square or
irregular shaped wires, which, when placed together, will form the section, or they
may be made of round wires, either made up in their natural form, or else pressed,
rolled or drawn together to form a nearly solid but flexible section. These
conductors insulate by paper diaphragms and wrappings, and they may, when
put together to form a circle with their insulation, be wrapped round again spirally
with paper.
In some cases,
I wrap each segmental paper with a spiral cutting of paper several
layers deep. It is not possible to burnish down the paper in the ordinary way upon
these conductors, and I therefore lay my paper so that it does not overlap, but so
that it comes butt jointed. I form several layers in this way, which break joint
with each other and so give a good insulation.
In making up some of the conductors above described, I use machinery which
carries reels of the conductor and also reels of insulating material: all these being
fed into the machine longitudinally, where they are twisted together and, in some
cases, have the edges of the insulating material turned down over the conductor.
In some cases, I draw the cable off the drum in the ordinary way, rotating the
conductors and insulation which go to form the cables. In another case, I féed
these in longitudinally from their drums, and rotate the taking off drum at right
angles to its axis of rotation for winding up the cable.
2

page_text: Where I have mentioned paper, I may use every suitable insulating material for
insulating the conductors. For example, the conductors of 20 or 30 feet long may
be wrapped with linen or calico, or some fibrous manufactured material or other
suitable insulation of this nature, and which is of the full width equal to the length
of the conductors. This may be obtained by taking strips of the insulating cloth
and cutting them to a length equal to the length of a conductor and then wrapping
them edgeways on to the conductor.
In some cases, I may take rigid conductors, insulated as described in the
Specification, and cover them with a tube of lead drawn down on to the insulation,
in some cases, pure indiarubber or indiarubber sheet or indiarubber tube may be
used for the purpose of insulation. I do not confine myself to the nature of the
insulation, as many different materials may be suitable for each particular
purpose.
I do not confine myself to making all the wires in any of the above described
conductors of equal section. It is specially desirable in the case of the three wire
conductors to have one of the wires, which is preferably the centre one, of a smaller
section than the others.
Where it is desired to make a three wire cable in which the centre wire is
earthed, I prefer to make up the lead and return in the form of segmental
conductors, to insulate these as described, and to either strand or place round
about this insulation the metal forming what is termed the "middle conductor" in
the three wire system. This may be insulated along its length and protected in
the ordinary way and put to earth at any desired position, or it may be exposed
to the earth all the way along so as to make contact naturally.
In making up electric cables of segmental section, I may wind the conductors
with jute or other vegetable fibre which may be impregnated with oil or insulating
compound before being covered with lead or other protection.
Or I may proceed as above described with segmental conductors insulated or
wrapped with cotton, jute or other vegetable fibre and draw them into pipes
or conduits laid in the ground and filled with oil or other liquid or plastic
insulator.
Or I may separately insulate the segmental conductors by passing through a
die and squirting on the insulation which may be bitumen (afterwards vulcanised)
or gutta percha or other material suitable to working in this way.
Or I may so form the die that I pass the several segmental or one circular and,
say, two segmental conductors through it and squirt the insulation around and
between them, so as to make up the conductors and the insulation at one or
successive operations. This cable may then be lead covered tape braided or (and)
armoured according to the work it has to do and the exact nature of the insulation
used.
Small segmental conductors may be made up with each wire of the full section
required and in one piece insulated and lead covered and the several conductors
twisted together as above explained. They will be sufficiently flexible without
lamination of the conductors.
Where segmental sections are twisted together, they must be made of such a
section that, after twisting with their insulation, they come to form the desired
circular section.
Where I wish to joint three wire segmental conductors, I spray out the con-
ductors and bend them so that the sides of the conductors from each cable to be
jointed lie flat together. These may be bound and soldered or brazed, or they may
be slipped into segmental tubes or pieces. Or they may be cramped together with
or without branch wires by suitable wedge-shaped cramps.
In any of these cases, if each segmental conductor is made up of several pieces,
they may be inter-placed or alternated one with another to give the best contact.
Where I wish to join a flexible three wire cable, one of the wires being a stranded
conductor and the other two each made of several segmental sections laid side by
side, I may solder the two ends of the central conductors into a tube. The

page_text: outer conductors may be joined to the corresponding ends of the other cable by
being soldered in between each other in a binding or U-shaped piece. I prefer
to give each conductor in one of the cables a half twist, as, when the segmental
pieces are then laid together, they form a solid mass nearly rectangular, and each
surface fits accurately.
Most of these joints can be made in metal chambers, lead soldered or cast iron
jointed, and run up with oil or other plastic or easily fusible insulator.
Where I have mentioned lead as a flexible waterproof protector, I may cover
the cable with a flexible metallic covering with packing in between the joints, so
that it both protects and waterproofs the cable, or I may use any other suitable
material or arrangement for protecting and waterproofing any one of the cables
above described.
Deted this 19th day of December 1892.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or relating to Electric Cables.
I, SEBASTIAN ZIANI DE FERRANTI of Charter House Square, London E.C. in
the County of Middlesex, Electrician, 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:-
My invention consists of improvements in electric conductors where more than a
single conductor is formed into the same cable.
It most commonly applies to cables made up of two conductors for the ordinary
system of distribution of electric energy, and to cables made up of three conductors
used for what is commonly known as the three wire system, but of course the
invention is applicable to cables formed of more than three conductors.
My invention refers both to cables in which the conductors are rigid and are
contained within a rigid protecting tube of iron or other metal, and also to cables
which are flexible and which may be coiled on a drum so that they can be
manufactured in fairly long lengths, according to ordinary well known practice.
The invention is best described by aid of the accompanying drawings in which
fifteen modifications of my invention are shown. These are given as illustrations
merely, and not as exhausting the subject. In these, the thick black portions are
insulation.
One distinguishing point in my invention, and which I claim as novel and very
useful though not necessary in all instances, is the building up of the conductor of a
series of segments unitedly forming the conductor with practically no air space
between.
This is shown especially in Figures 9, 10, 13, 14 and 15, and, as far as regards
the outer conductors, in Figure 11.
To form a cable of my rigid conductors, I prefer to make the conductors of
segmental pieces of copper of such a size that, when they are insulated and laid
together, the combination forms a circle or part of a circle. This is shown in
Figure 15 as a complete circle: and Figures 9, 10, 11, 13 and 14, as segments of
circles or cylinders built up of smaller segments. I am aware that cylinders of
copper have been used to form rigid electrical cables. In my invention, however,
I make such cables and their conductors in lengths of 20 or 30 feet, and wind each
one with paper or other insulating fabric the full length of the conductor, wound
itself a number of times until the requisite thickness is obtained. The paper,
for instance, can be of ordinary five feet width and cut in lengths equal to that of
the cable, and throughout this Specification the word "paper" must be read to
include any flexible sheet tough insulating material.
upon
I immerse this paper in oil, earth, wax or other suitable insulator, in order to

page_text: render it a better insulator, and preferably wind it on to the conductor not, keeping
the conductor and insulation in a liquid insulating bath.
When the two conductors are placed together and, with their insulation, form a
circle, prefer to roll them round with a further number of layers of paper, as
above explained. They are then drawn into an iron tube, which is either drawn
down upon them by passing through a drawbench, or else wax or some insulator
which sets firm is forced in to hold them in position.
Where three conductors are to be used to form a single rigid cable, I may make
them in several different forms.
Thus, as illustrated in Figure 1, I take a rod of copper, A, of the desired section,
and from 20 to 30 feet long. I roll this with paper as above explained. Upon
this I lay two semi-circular pieces of copper, B C, but which are of such dimensions
that, when they are laid upon the insulation of the first conductor, they have a
small clearance between their respective edges. This clearance or space I fill
with jute or some vegetable fibre or other suitable insulator. The combination then
forms a circle, and this circle of copper and insulation I wind preferably with a
number of layers of paper treated as above explained. This may be placed in a
wrought iron or other suitable protecting tube D.
Figure 2 shows two segmental conductors BC and one flat one, A, between
them; all of which, when wound with a small thickness of insulation, as above
explained, will form themselves, when put together, in the form of a circle, which
circle I may wind with more paper and protect as above explained.
Figure 3 shows three segmental conductors, A, B and C, each of which occupies
nearly one-third of the circle, and which, when each one is separately wound with
paper and the three are laid together, form approximately a circle, and which may
be treated with more layers of paper or insulating material and protected as above
explained.
The last described arrangement may be advantageously constructed as-
follows:-
I may take the three segmental pieces of copper and lay them together to form
a circle with cut strips of paper laid in between each, as set forth in Figure 5, so
that two of these pieces come between each conductor, the edges of the paper
standing out to a considerable distance, as shown in the Figure 5. I may then
spread out this paper by means of suitable apparatus, such as drawing through a
die or mould, so that it laps round the outside of the segmental conductors and so
protects them. I may even arrange it in such a manner that the sheets overlap so
that there may be no butt joint. I may then take the conductors so insulated
and wrap them with paper and protect them in a metal tube D, as above explained.
Figure 4 shows a slight variation, where two segmental conductors, BC, are
insulated by sheets of paper placed between them with the ends projecting, and
these pressed over and wound with fresh paper: a third conductor A is then placed
round them, then a fresh insulation, and over that a lead tube D.
Where there are more than three conductors, I prefer to make the separate
conductors in the form of segments of a circle. In some cases, it is desirable to
start the basis of the cable in the form of a circular conductor of the necessary
section insulated by wrapping with paper. The separate segmental conductors
round about it are then separately wrapped with paper placed round about the
central conductor, and the whole is then wrapped and protected as above explained.
This is set forth in Figure 6, where A is a central conductor: B C E F, four
segmental conductors.
I vary the arrangement in the following manner, when it is desirable that the
conductor shall be of the flexible type :-
Where I desire to use two conductors to form one cable, I may lay up wires to
.form two nearly semi-circular sections of copper, as set forth in Figure 7. These
wires I hold in position during manufacture by passing through a die, and I twist
them together with insulation between their flat opposing surfaces, so as to form an
approximately circular body. These may be insulated on the outside with a paper

page_text: wrapping, or in any other suitable way, and may be then finished with a lead pipe D
for purposes of protection.
By one method, I make the insulating diaphragm between the two conductors of
paper and of sufficient width that the edges of the paper sticking out on each side
of the conductors may be turned over so as to wrap round the sides of the conductors,
and so insulate them, as explained in relation to the solid conductors, and as set
forth in Figure 8.
According to another method, I do not form the conductors simply of a bundle of
wires arranged to form a segment of a circle, but I form them either of a bundle or
strands of wires, and then, by means of either drawing through dies or rollers or
compressing into a mould, I form them into a laminated conductor, but which is
segmental in section and contains nearly the same weight of copper as a rigid bar
of the same external section. These I twist together and insulate as above
described.
In Figure 9, these segmental conductors are built up out of a number of
approximately radial sided segmental pieces, which, when put together, form the
necessary segmental shape, so that, when separated by insulation, they form a
circle. By this means, conductors of segmental form are obtained, which contain
practically as much copper as solid conductors, and yet which are flexible. These,
if desired, can be separated by sheets of paper, two between each strand, and
projecting out beyond the circumference; they are then twisted together and rolled
to a circular shape at the same time, and the extra paper flaps rolled over them.
The object of making them of this form is so that each conductor should present a
portion of its surface to the outside circle to facilitate soldering on connections which
should make contact over every part of the conductors as a whole. The insulation
may be carried out according to any of the methods above described. These
opposing conductors may be twisted together with insulation, as above explained,
to form a fairly flexible cable.
Figure 10 shows the segmental conductors built up of wires of square (or they
could be other shaped) section, which, when put together, form approximately half
a circle. These pass through dies to lay them up together in their respective
positions. They may then be twisted together and treated generally as above
described.
Where three conductors are required to form a single flexible cable, I prefer to
make my first conductor of stranded copper of circular section. This is shown in
Figure 11, at A. I wrap this with insulating paper. Around this 1 strand a
number of separate wires of segmental section, half of which touch each other to
form one conductor B and the other half of which touch each other to form the
remaining third conductor C. In between the segments thus formed round the
circle, I strand jute or vegetable fibre or other insulating material to keep them
apart, and to make them up a complete circle. This circle of copper and
insulation I then wrap round separately with paper, which is afterwards impreg
nated with oil, wax or other insulating material, either before the process of
manufacture, in stages during the manufacture, or after the whole of the insulating
material has been applied, and the cable made up save and except its protecting
lead sheath D.
In place of making the cable entirely as above described, I may make the two
conductors, which form nearly semi-circular layers of copper round the insulation
of the first conductor, of wires simply stranded round with the jute or other
fibre, separating them in two places to form two separate conductors, as above
described.
I sometimes bunch three sets of conductors, each set to form nearly the third of
a circle, but which, when stranded up together with insulation in between them,
form three separate spiral conductors of approximately circular section as a whole.
These may be insulated as above described for solid conductors, or may be separated
in the same way and finished with a spiral wrapping of paper and a tube of lead D,
as shown in Figure 12.

page_text: This may be slightly modified by obtaining the above sections by drawing the
above mentioned conductors through a die or rollers or pressing them in moulds, as
before, before they are twisted up to form a circle, so that they may form a more
definite section and more copper may be got into the space, or the twisting and
rolling can be accomplished simultaneously.
I may obtain 3 conductors in one cable, each one of the sections described above,
by taking a larger number of segmental shaped conductors, several of which are laid
together to make up each separately insulated conductor, and these conductors may
be twisted together with their insulation, and dealt with as above described. This
is especially shown in Figure 13.
Figure 14 illustrates the case where I wish to make a cable of three conductors,
and I make two of them as already described of nearly semi-circular section, and
the third one a flat strip in between. These sections may be made up of square or
irregular shaped wires, which, when placed together, will form the section, or they
may be made of round wires, either made up in their natural form, or else pressed,
rolled or drawn together to form a nearly solid but flexible section. These
conductors I insulate by paper diaphragms and wrappings, and they may, when put
together to form a circle with their insulation, be wrapped round again spirally with
paper.
Figure 15 shows a slightly different form where conductor A, instead of being
between B and C, is built up round the insulation covering B and. C.
In some cases, I wrap each segmental paper with a spiral cutting of paper several
layers deep. It is not possible to burnish down the paper in the ordinary way upon
these conductors, and I therefore lay my paper so that it does not overlap, but so
that it comes butt jointed. I form several layers in this way, which break joint
with each other and so give a good insulation.
In making up some of the conductors above described, I use machinery which
carries reels of the conductor and also reels of insulating material; all these being
fed into the machine longitudinally, where they are twisted together and, in some
cases, have the edges of the insulating material turned down over the conductor.
In some cases, I draw the cable off the drum in the ordinary way, rotating the
conductors and insulation which go to form the cables. In another case, I feed
these in longitudinally from their drums, and rotate the taking off drum at right
angles to its axis of rotation for winding up the cable. The machinery employed
for the purpose is so well known to cable manufacturers, that it is unnecessary to
give a description of it here, especially as it does not form a part of my present
invention.
Where I have mentioned paper, I may use every suitable insulating material for
insulating the conductors. For example, the conductors of 20 or 30 feet long may
be wrapped with linen or calico, or some fibrous manufactured material or other
suitable insulation of this nature, and which is of the full width equal to the length
of the conductors. This may be obtained by taking strips of the insulating cloth
and cutting them to a length equal to the length of a conductor and then wrapping
them edgeways on to the conductor.
In some cases, I may take rigid conductors, insulated as described in the Specifica-
tion, and cover them with a tube of lead drawn down on to the insulation, in some
cases, pure indiarubber or indiarubber sheet or indiarubber tube may be used for the
purpose of insulation. I do not confine myself to the nature of the insulation, as
inany different materials may be suitable for each particular purpose.
I do not confine myself to making all the wires in any of the above described
conductors of equal section. It is specially desirable in the case of the three wire
conductors to have one of the wires, which is preferably the centre one, of a smaller
section than the others.
Where it is desired to make a three wire cable in which the centre wire is
earthed, I prefer to make up the lead and return in the form of segmental
conductors, to insulate these as described, and to either strand or place round about
this insulation the metal forming what is termed the "middle conductor" in the

page_text: three wire system. This may be insulated along its length and protected in the
ordinary way and put to earth at any desired position, or it may be exposed to
the earth all the way along so as to make contact naturally. Its manner of building
up is set forth in Figure 15.
In making up electric cables of segmental section, I may wind the conductors
with jute or other vegetable fibre which may be impregnated with oil or insulating
compound before being covered with lead or other protection.
Or I may proceed as above described with segmental conductors insulated or
wrapped with cotton, jute or other vegetable fibre and draw them into pipes or
conduits laid in the ground and filled with oil or other liquid or plastic insulator.
Or I may separately insulate the segmental conductors by passing through a die
and squirting on the insulation which may be bitumen (afterwards vulcanised) or
gutta percha or other material suitable to working in this way.
Or I may so form the die that I pass the several segmental or one circular and,
say, two segmental conductors through it and squirt the insulation around and
between them, so as to make up the conductors and the insulation at one or
successive operations. This cable may then be lead covered taped braided or (and)
armoured according to the work it has to do and the exact nature of the insulation
used.
Small segmental conductors may be made up with each wire of the full section
required and in one piece insulated and lead covered and the several conductors
twisted together as above explained. They will be sufficiently flexible without
lamination of the conductors.
Where segmental sections are twisted together, they must be made of such a
section that, after twisting with their insulation, they come to form the desired
circular section.
Where I wish to joint three wire segmental conductors, I spray out the conductors
and bend them so that the sides of the conductors from each cable to be jointed lie
flat together. These may be bound and soldered or brazed, or they may be slipped
into segmental tubes or pieces; or they may be cramped together with or without
branch wires by suitable wedge-shaped cramps.
In any of these cases, if each segmental conductor is made up of several pieces,
they may be inter-placed or alternated one with another to give the best contact.
Where I wish to join a flexible three wire cable, one of the wires being a stranded
conductor and the other two each made of several segmental sections laid side by
side, I may solder the two ends of the central conductors into a tube. The outer
conductors may be joined to the corresponding ends of the other cable by being
soldered in between each other in a binding or U-shaped piece. I prefer to give
each conductor in one of the cables a half twist, as, when the segmental pieces are
then laid together, they form a solid mass nearly rectangular, and each surface fits
accurately.
Most of these joints can be made in metal chambers, lead soldered or cast iron
jointed, and run up with oil or other plastic or easily fusible insulator.
Where I have mentioned lead as a flexible waterproof protector, I may cover the
cable with a flexible metallic covering with packing in between the joints, so that
it both protects and waterproofs the cable, or I may use any other suitable material
or arrangement for protecting and waterproofing any one of the cables above
described.
In concluding this description, I would point out the following salient points in
my invention. I believe this is the first time that conductors have been formed in
segments of circles in such manner that two or more segmental conductors with
their insulations united form a cylinder, also I believe to be new and original with
me the building up of segmental or other conductors of a number of separate
segmental forms unitedly forming a segmental conductor such as described, but I
do not claim in this application the forming of the conductors in concentric circles
unless those circles be formed in whole or in part of separate segments unitedly
forming a cylinder or segment of a cylinder.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is―
1. The manufacture and also the joining up of electric cables substantially as
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is―
1. The manufacture and also the joining up of electric cables substantially as
herein described.
2. A cable having a cross section substantially similar to any of those set forth
in the drawings.
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Nottingham, and London, Patent Agents.