Improvements in Multiple Electric Conductors or Cables for Telegraphic, Telephonic, and other Purposes, and in Processes апа
Year: 1886

page_text: Improvements in Multiple Electric Conductors or Cables for
Telegraphic, Telephonic, and other Purposes, and in Processes
апа
I BENJAMIN JOSEPH BARNARD MILLS of the firm of Harris and Mills of
23 Southampton Buildings in the County of Middlesex, Patent Agent, do hereby
declare the nature of this invention, a communication to me from abroad by
John Joseph Charles Smith and Michael Smith, both of Passaic, in the State of
New Jersey, United States of America, Insulated wire and cable manufacturers,
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :—
This invention has for its object the construction of insulated conductors and
cables for underground, submarine and aerial uses.
The invention relates in part to improvements in methods and appliances
employed for the vulcanization of the insulating coverings of conducting wires.
The object of these improvements is to prevent the dislocation of the inetallic
conductor from the centre of the rubber or other covering during vulcanization.
After a wire has been covered with rubber composition or other vulcanizable
compound for insulation, much difficulty exists in keeping the conducting wire in
its proper position in the centre of the insulating cover during the process of
vulcanization: The first effect of the heat required to accomplish vulcanization is.
to soften the compound so much that the weight of the wire will cause it to settle
or sink in the plastic covering and thus dislocate it from its proper central position.
This difficulty is greatly enhanced when a continuous length of several hundred
feet is to be operated on and it results in serious imperfection in the insulation.
pans.
One common expedient to partially overcome this difficulty is to pack the
covered wire closely in dry soapstone powder or like material in large metallic
This is however a laborious and troublesome process i
Another common
expedient is to make the vulcanizable composition very stiff by a large admix-
ture of oxides and other materials to prevent its softening by heat; but this is
injurious to good insulation.
In order to prevent the dislocation of the wire during vulcanization, while using
a compound possessing the best insulating properties the present improvement in

page_text: the vulcanizing process consists essentially in keeping the covered wire in motion
during vulcanization so that it cannot settle toward the surface in any direction.
The wire being covered with insulating composition by any of the known modes,
the covered wire is coiled on a large metallic reel or drum in regular spirals so that
two or three layers may be applied, care being observed that it is laid in loose coils
without tension. The reel is mounted in a carriage by which when charged it is
run into the vulcanizer, and the reel shaft has a clutch connection with external
gearing by which a constant rotary motion is communicated to the reel and its
charge of covered wire during the vulcanizing operation.
The improved cable is made up of any desirable number of conducting wires
permanently insulated from each other and from external influences and so
effectually protected against mechanical injury that the cable may be laid under-
ground with entire safety without a containing tube or conduit. ·
In order to secure the effective and permanent insulation of the conductors, the
necessary flexibility of the cable and its protection from injury, it is made as
follows;
A hollow core is first formed of tightly coiled wire and is covered with a
braided envelope of cotton. On this any desired number of covered conducting
wires are wound in long spirals and in one or more layers, according to the capacity
or the number of conductors required in the cable.
The covering of the individual wires may be of rubber vulcanized to prevent
cohesion between the different wires but a more economical covering for the wires
for cable purposes is made by braiding cotton around them, this braided cover
being adapted to be permeated by fusible insulating material which is forced, hot,
into the interior of the cable after it is made up as hereinafter described, and per-
mitting the ready separation of the wires if it ever become necessary. A covering
of tape coated on the outside with raw rubber composition is then tightly would
over the covered conductors, the bare side of the tape being on the inside so
as to prevent cohesion to the covered wires. This is then covered with an
impervious envelope of vulcanizable compound surrounded with tin foil and this
with crossed layers of tape coated with the raw rubber or like compound after
which the covered cable is coiled on a reel and placed in a vulcanizer and the
envelope vulcanized, care being taken to prevent any ingress of steam within the
hollow core. A hollow cable is thus produced with a seamless vulcanized covering,
air and water tight. This is then covered with protective armour formed of a
layer of wire of moderate size wound in long spirals and an outer layer of larger
wire wound in very short spirals. The interior of the cable is then connected with
pipes and pumps or other suitable apparatus by which its whole interior is first
heated by forcing hot paraffine oil into and through it and is then filled with melted
paraffine or like fusible non-conducting material which displaces the oil and com-
pletely fills the interstices between the covered wires and core and the hollow
core itself and permeates the meshes of the cotton envelopes around and between
them.
In the accompanying drawings Figure 1 is a transverse section of a cable
illustrating the invention. Figure 2 is a longitudinal section of the same on the
line II-II, Figure 1.
Figure 3-is an exterior view, on.a.smaller scale with parts of the cable separated.
Figure 4 is a side elevation of a reel and carriage suitable for the reception of
covered wire for vulcanization.
Figure 5 is a front view of the vulcanizing vessel and the reel within it with
the cover of the vulcanizer removed.
Figure 6 is a longitudinal section of the vulcanizing vessel and reel in position
for operation.
Figure 7 is an illustration of an apparatus suitable for filling the hollow cable
with paraffine, showing parts of the cable, in position for filling.
In Figures 1, 2, 3, 1 represents a flexible hollow core made by winding a No 14
wire to a close spiral, continuing this to any length desired for the cable. Instead
of this the core may be formed of a perforated lead pipe, but it is preferred to use

page_text: a spiral hollow core formed of wire, as first specified. This hollow core is covered
with a layer of cotton thread 2, by braiding.
Any desired number of copper wires 3, which are to form the conductors,
covered with two or more layers of cotton thread 4, one layer by winding, the
next by braiding, are then laid around the covered flexible core 1, 2, by means of a
cabling machine so as to fully surround and cover the flexible tube.
In order to insure uniform flexibility in the cable the covered conducting wires
are laid in a long winding spiral, as is usual in laying électric conductors around
a core.
The first layer of cotton covered wire is followed by a second wound around the
centre in the opposite direction and the second may be followed by a third and so
on according to the number of conductors required in the cable. When the
desired number of conductors are thus laid up in the cable the whole body-of
covered conducting wires is surrounded and firmly bound together with a layer of
tape 5, made from cotton cloth rubbed over, on one side, with rubber composition.
This tape is applied with the cloth face, on the inside, next to the cotton covered
wires and the rubber covered side on the exterior.
The cable thus far formed, is. next covered with a layer of insulating rubber
compound 6, about one sixteenth of an inch thick. This rubber compound is best
applied in the form of a longitudinal strip in the same manner and with a machine
similar to that employed in applying a rubber covering to a single conductor, as
described in Letters Patent granted to J. J. C. Smith dated the seventh day of
October 1882 No 4768 with a sheet of tin or other metal foil 7, outside the rubber'
composition as described in Patent No 5828 of 1885. The metal foil is left in
position on the outside of the insulating rubber compound and covered a
İnyer of cotton tape, 8 rubbed over on both sides with rubber compound. he
tape is wound spirally around the cable and is followed by a second layer 9-1' a
similar tape wound in the opposite direction, so as to cross the joints.
When these two layers of tape are applied the formation of the cable is far
enough advanced to be ready for a partial vulcanization of the insulating rubber
cover. To effect this the cable is wound on a large drum and its ends hermetically
closed to prevent the entrance of the steam within the impervious insulating cover,
which would have the deleterious effect of moistening the cotton around the wires..
The drum with its charge of cable is then placed in a proper vulcanizing vessel.
The drum is slowly revolved during vulcanization in order that the desired effect
may be produced upon all parts of the cable and especially to prevent any unequal
settling of the parts by gravity, which might impair the symmetry of the cable,
and produce inequalities in thickness in the insulating covering of the body of
conducting wires. The heat is produced by steam at a temperature of 250 degrees
Fahrenheit for forty minutes.
A suitable apparatus for reeling the cable or single covered wire for vulcanizing,
the envelope is represented in Figures 4, 5 and 6.
This apparatus is constructed with a reel 21, of light wrought iron, of such size,
as the quantity of covered wire or cable to be treated at once, may require.
A reel twelve feet long and four feet in diameter will hold about two miles of
wire, laid on in three courses.
A shaft 22, extends through the rear end 23 of the vulcanizing vessel 24 which
is provided with a stuffing box 25. The shaft 22, has on the inside of the vessel a
clutch 26, and is provided on the outside with gearing 27, by means of which a
slow rotary motion may be given to the shaft.
The shaft 28 of the reel 21 is also provided with a clutch 29, at the end. When,
the reel is charged with a desired quantity of covered conductor or cable C, it is
placed in the vulcanizing vessel 24.
To facilitate the introduction and removal of the reel and its rotation while in
the vulcanizing vessel it is mounted in bearings in a carriage 31 having small
wheels or rollers 32 running on corresponding rails 33 in the vessel.

page_text: The clutches 26 and 29, on the shafts 22 and 28 lock together when they meet.
The door or cover 34 of the vessel is closed, and the reel inside is set in rotary
motion by means of the shaft 22 and its gearing. The reel should make only three
or four revolutions per minute.
In the common mode of embedding covered wire in soapstone during vulcaniza-
tion the wire is not only subject to dislocation by the effect of gravity but the
longitudinal expansion of the conductor by heat during vulcanization is an
additional and very serious cause of dislocation of the conductor from the centre
of the covering.
With the present improvement the covered conductor is by the rotation of the
reel continually changed in its position so far as the weight or gravity of the
conductor is concerned.
"
Hence the weight of the conductor on its soft covering cannot gradually press it
aside as if it rested quietly; because the rotation of the reel brings the conductor
in a different position by every inch of rotary motion.
Furthermore, the metallic conductor has freedom for longitudinal expansion;
being spirally and loosely wound on a reel which is kept in motion in the same
direction as the conductor is wound; the expansion is thus gradually taken up by
the slow rotary motion of the reel, as the heat lengthens the conductor...
The drum, with the cable coiled upon it being removed from the vulcanizer we
have a cable combining two valuable features to wit; (I) a hollow flexible centre
with.numerous openings in its walls, and (II) a number of conducting wires each
separated from the rest by cotton, but all of them surrounded and firmly held
together by an envelope which serves not only as an outside insulator for the
conductors but also as an exceedingly flexible and absolutely waterproof covering
made still more impervious by a layer of metal foil which surrounds and tightly
envelops it, and it is further protected by a double layer of tape.
The next step in the process is to cover the cable with a metal armour to protect
it against mechanical injury and to prevent any rupture or distortion of the
insulating envelope around the body of conducting wires in the operation of
introducing insulating material in a melted state and under high pressure, as
hereinafter explained.
. The metal armour is made double in two layers of wire of different thicknesses
applied in the following manner, specially devised to combine flexibility with
effectual protection. The first shield or armour 10, consists of a number of wires,
say about No 14 Stubb's gauge, all wound at once spirally round the cable making
one turn to about every foot, laid closely enough to cover the surface of the cable
completely. The first armour is succeeded by a second one 11, consisting of two
heavier wires of about one-eighth of an inch in diameter. These two wires are
wound side by side, over the first armour in regular spiral turns, covering the
cable solidly and completely, but nevertheless making a very flexible cable. This
double armour serves two very important purposes, as stated above.
When the cable is armoured, the interior space left between the wires, cotton
and covering is filled with a good insulating material 12 which will become fluid
by heat and congeal at a temperature of about 140° Fahrenheit.
For this filling, paraffine or ozocerite or-rosin may be used, a good-mixture-for
the purpose consists of two parts ozocerite with two parts rosin, and one part
india rubber dissolved in benzine and mixed with the ozocerite and rosin when
melted.
The filling of the cable with said mixture is accomplished in the following
manner. The cable C, is wound on a large drum D, as illustrated in Figure 7 and
one end of the cable is provided with a proper metallic coupling 13.
The coupling 13 is so arranged as to quickly and perfectly connect the hollow
core of the cable with a nozzle 14 and thus with either of the supply pipes 15, 16
from two force pumps 17, 18 the first being for oil and the other for the liquid
insulating material. The other end of the cable is arranged to discharge into the
tank 19 containing oil heated to at least 250° Fahrenheit.

page_text: The hot ou is forced through the hollow cable to heat up the wires and cotton
and carry off all air and moisture.
This is kept up for about half an hour, then the oil is shut off. The pipe 16 is
then opened and the force pump 18 which is connected with a vessel 20 containing
a supply of melted wax or fusible insulating compound is put in operation and the
interior of the cable is completely filled with the melted insulating material.
Pressure is applied to the melted material by means of the force pump which may
be brought to about 200 lbs. to the square inch so as to make sure that the melted
material will penetrate into every interstice and pore which may exist between
the wires, threads of cotton and the outside covering. For this purpose a
coupling 13 and nozzle with a cock 13b may be applied to the discharge end of
the cable. The cable is then allowed to cool off to solidify the wax or other
insulating body and is ready for use.
If the cable be designed for aerial use, where lightness is a desideratum, a strong
hemp cover is substituted for the metal armour for the purpose of preventing the
bursting of the rubber envelope by internal pressure and protecting the cable from
external injury;
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
:
1. The combination of the hollow spiral core, 1, insulated conducting wires 3
impervious envelope 6, and a filling of wax or other fusible insulating material.
2. The combination of a flexible hollow core adapted to permit the passage of
melted insulating material, covered wires surrounding the said core and an
envelope composed of insulating and fibrous material, and sheet metal, the fibrous
material being united to the insulating envelope in process of vulcanization and
preventing cohesion between the same and the covers of the individual wires.
3. The protecting armour consisting of diversely wound spiral wires 10, 11, as
explained, in combination with the hollow core 1, covered wires 3 and insulating
envelope 6 as and for the purposes set forth.
4. The electric cable herein described consisting of the hollow flexible core 1
adapted to permit the passage of melted insulating material, the covered wires 3,
surrounding said core, the impervious envelope 6, 7, 8 surrounding said wires, the
flexible armour 10, 11, and the fusible non-conducting filling 12, as and for the
purposes set forth.
.
5. The apparatus for vulcanizing insulating envelopes of electrical conductors
or cables, consisting essentially of a vulcanizing chamber, a reol for carrying the
covered conductor and gearing for rotating the reel and its charge during the
process of vulcanization, as explained.
6. The combination of a vulcanizing vessel having a shaft and gearing for
rotating said shaft and a reel mounted on a carriage and provided with a clutch
for connecting it with the shaft and gearing so as to receive rotation therefrom as
explained.
7. The process of vulcanizing the insulating envelope of electric conductors or
cables, the same consisting in winding the covered conductor or cable on a reel or
drum and slowly rotating the same while in the vulcanizing vessel and during the
process of vulcanization, substantially as set forth.
8. The process of making an electric conducting cable, the same consisting in
laying the conducting wires around a hollow core adapted for the forcing through
it of insulating material in a melted state, covering the said wires with an
impervious envelope of insulating material and subsequently filling the interstices
between the conducting wires, envelope and core with insulating material forced
in in a melted state as explained.
9. The process of making an electric conducting cable, the same consisting in
laying the conducting wires around a hollow core adapted for the forcing through
it of insulating material in a melted state, covering the said wires with an envelope

page_text: of vulcanizable material, vulcanizing or partially vulcanizing the envelope by moist
heat applied to the outside only and excluded from the interior, and then forcing
into the core a body of insulating material in a melted state to fill the interstices,
substantially as set forth.
10. The process of making an electric conducting cable, the same consisting in
laying covered conducting wires around a hollow core adapted for the passing
through its walls of material in a melted or semi-liquid state, enveloping the coil
or body of conducting wires with vulcanizable material separated from them by
fibrous material to prevent cohesion, then vulcanizing or partially vulcanizing the
envelope and subsequently filling the interstices between the covered wires,
envelope and core with material forced in, in a melted or semi-liquid state through
the hollow core.
11. The process of making an electric conducting cable, the same consisting in
laying conducting wires around a central hollow core adapted to permit the
passage through its walls of liquid or semi-liquid matter, covering the body of
conducting wires with an impervious envelope, surrounding this with a spiral
armour of wire for the purposes of protecting the cable against mechanical injury
and resisting internal pressure, and then forcing into the hollow core and out
through the walls. thereof melted or semi-liquid matter to fill the interstices
between the conducting wires, envelope and core.
12. The process of making an electric conducting cable, the, same consisting in
wrapping insulated conducting wires around a hollow core, enveloping the body of
wires in a sheet of vulcanizable material, and subsequently vulcanizing the same
by moist heat applied to the outside only and excluded from the interior..
13. The process of making electric cables substantially as herein described, the
same consisting in laying any desirable number of conducting wires with fibrous
coverings around a hollow core having passages in its walls, enveloping the said
body of conductors in an impervious envelope, forcing heated liquid through the
cable to remove the air and heat the interior, and subsequently forcing in
insulating material in a melted state to fill the interstices between the conducting
wires.
14. The process herein described for insulating wires in electric cables, the same
consisting in forcing through a hollow cable a current of heated oil to heat the
interior and expel air therefrom, and then forcing in a body of melted insulating
material to displace the oil, as explained.
15. The apparatus for filling hollow electric cables, consisting of one or more
forcing pumps, separate tanks for containing heated oil and melted insulating wax
or like material and suitable pipe connections, couplings and stop cocks to permit
the injection of hot oil and melted wax, successively, as explained.
16. The combination of the reel D, a cable C coiled thercon, a forcing pump 18
tanks 19 and 20, respectively for oil and wax or the like and suitable pipe
connections and stop cocks to enable the successive injection of oil and insulating
material into the cable as explained.
17. The combination of the tanks 19 and 20, pumps 17 and 18 and pipes 14,
15, 16, provided with suitable stop cocks and couplings, substantially as and for
the purposes set forth.

page_text: This Specification was, upon the 30th day of August 1887, amended under
Sections 18 to 21 of the Patents, Designs, and Trade Marks Act, 1883.
[Communicated from abroad by John Joseph Charles Smith and Michael Smith,
both of Passaic, in the State of New Jersey, United States of America,
Insulated Wire and Cable Manufacturers.]
Improvements in Multiple Electric Conductors or Cables for
Telegraphic, Telephonic, and other Purposes, and in Processes
and Apparatus for the Manufacture of Insulated Conductors
and Cables.
I BENJAMIN JOSEPH BARNARD MILLS of the firm of Harris and Mills of
23 Southampton Buildings in the County of Middlesex, Patent Agent, do hereby
declare the nature of this invention, a communication to me from abroad by
John Joseph Charles Smith and Michael Smith, both of Passaic, in the State of
New Jersey, United States of America, Insulated wire and cable manufacturers,
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
--
This invention has for its object the construction of insulated conductors and
cables for underground, submarine and aerial uses.
The invention relates in part to improvements in methods and appliances
employed for the vulcanization of the insulating coverings of conducting wires.
The object of these improvements is appliances being to prevent the dislocation of
the metallic conductor from the centre of the rubber or other covering during
vulcanization.
After a wire has been covered with rubber composition or other vulcanizable
compound for insulation, much difficulty exists in keeping the conducting wire in
its proper position in the centre of the insulating cover during the process of
vulcanization. The first effect of the heat required to accomplish vulcanization is
to soften the compound so much that the weight of the wire will cause it to settle
or sink in the plastic covering and thus dislocate it from its proper central position.
This difficulty is greatly enhanced when a continuous length of several hundred
feet is to be operated on and it results in serious imperfection in the insulation.
015

page_text: One common expedient to partially overcome this difficulty is to pack the
covered wire closely in dry soapstone powder or like material in large metallic
pans.
This is however a laborious and troublesome process Another common
expedient is to make the vulcanizable composition very stiff by a large admix-
ture of oxides and other materials to prevent its softening by heat; but this is
injurious to good insulation.
In order to prevent the dislocation of the wire during vulcanization, while using
a compound possessing the best insulating properties the present improvement in
connected with the vulcanizing process.consists essentially in an improved construction
of apparatus for keeping the covered wire in motion during vulcanization so that
it cannot settle toward the surface in any direction.
The wire being covered with insulating composition by any of the known modes,
the covered wire is coiled on a large metallic reel or drum in regular spirals so that
two or three layers may be applied, care being observed that it is laid in loose coils
without tension. The reel is mounted in a carriage by which when charged it is
run into the vulcanizer, and the reel shaft has a clutch connection with external
gearing by which a constant rotary motion is communicated to the reel and its
charge of covered wire during the vulcanizing operation.
The improved cable is made up of any desirable number of conducting wires
permanently insulated from each other and from external influences and so
effectually protected against mechanical injury that the cable may be laid under-
ground with entire safety without a containing tube or conduit.
In order to secure the effective and permanent insulation of the conductors, the
necessary flexibility of the cable and its protection from injury, it is made as
follows A hollow core is first formed of tightly coiled wire and is covered with a
braided envelope of cotton. On this any desired number of covered conducting
wires are wound in long spirals and in one or more layers, according to the capacity
or the number of conductors required in the cable.
The covering of the individual wires may be of rubber vulcanized to prevent
cohesion between the different wires but a more economical covering for the wires
for cable purposes is made by braiding cotton around them, this braided cover
being adapted to be permeated by fusible insulating material which is forced, hot,
into the interior of the cable after it is made up as hereinafter described, and per-
mitting the ready separation of the wires if it ever become necessary. A covering
of tape coated on the outside with raw rubber composition is then tightly would
wound over the covered conductors, the bare side of the tape being on the inside so
as to prevent cohesion to the covered wires. This is then covered with an
impervious envelope of vulcanizable compound surrounded with tin foil and this
with crossed layers of tape coated with the raw rubber or like compound after
which the covered cable is coiled on a reel and placed in a vulcanizer and the
envelope vulcanized, care being taken to prevent any ingress of steam within the
hollow core. A hollow cable is thus produced with a seamless vulcanized covering,
air and water tight. This is then covered with a protective armour formed of a
layer of wire of moderate size wound in long spirals and an outer layer of larger
wire wound in very short spirals. The interior of the cable is then connected with
pipes and pumps or other suitable apparatus by which its whole interior is first
heated by forcing hot paraffine oil into and through it and is then filled with melted
paraffine or like fusible non-conducting material which displaces the oil and com-
pletely fills the interstices between the covered wires and core and the hollow
core itself and permeates the meshes of the cotton envelopes around and between
them,
In the accompanying drawings Figure 1 is a transverse section of a cable
illustrating the invention. Figure 2 is a longitudinal section of the same on the
line [I-II, Figure 1.
Figure 3 is an exterior view, on a smaller scale with parts of the cable separated.

page_text: Figure 4 is a side elevation of a an improved reel and carriage suitable for the
reception of covered wire for vulcanization.
Figure 5 is a front view of the vulcanizing vessel and the reel within it with
the cover of the vulcanizer removed.
Figure 6 is a longitudinal section of the vulcanizing vessel and reel in position
for operation.
Figure 7 is an illustration of an apparatus suitable for filling the hollow cable
with paraffine, showing parts of the cable in position for filling.
In Figures 1, 2, 3, 1 represents a flexible hollow core made by winding a N° 14
wire to a close spiral, continuing this to any length desired for the cable. Instead
of this the core may be formed of a perforated lend pipe, but it is preferred to use
a-spiral-hollow core formed of wire, as first specified. This spiral hollow core is
covered with a layer of cotton thread 2, by braiding,
Any desired number of copper wires 3, which are to form the conductors,
covered with two or more layers of cotton thread 4, one layer by winding, the
next by braiding, are then laid around the covered spiral flexible core 1, 2, by
means of a cabling machine so as to fully surround and cover the flexible tube.
In order to insure uniform flexibility in the cable the covered conducting wires
are laid in a long winding spiral, as is usual in laying electric conductors around
a core.
The first layer of cotton covered wire is followed by a second wound around the
centre in the opposite direction and the second may be followed by a third and so
on according to the number of conductors required in the cable. When the
desired number of conductors are thus laid up in the cable the whole body of
covered conducting wires is surrounded and firmly bound together with a layer of
tape 5, made from cotton cloth rubbed over, on one side, with rubber composition.
This tape is applied with the cloth face, on the inside, next to the cotton covered
wires and the rubber covered side on the exterior.
.
The cable thus far formed, is next covered with a layer of insulating rubber
compound 6, about one sixteenth of an inch thick. This rubber compound is best
applied in the form of a longitudinal strip in the same manner and with a machine
similar to that employed in applying a rubber covering to a single conductor, as
described in Letters Patent granted to J. J. C. Smith dated the seventh day of
October 1882 N° 4768 with a sheet of tin or other metal foil 7, outside the rubber
composition as 'described in Patent No 5828 of 1885. The metal foil is left in
position on the outside of the insulating rubber compound and covered with a
layer of cotton tape, 8 rubbed over on both sides with rubber compound. The
tape is wound spirally around the cable and is followed by a second layer 9, of a
similar tape wound in the opposite direction, so as to cross the joints.
When these two layers of tape are applied the formation of the cable is far
enough advanced to be ready for a partial vulcanization of the insulating rubber
cover. To effect this the cable is wound on a large drum and its ends hermetically
closed to prevent the entrance of the steam within the impervious insulating cover,
which would have the deleterious effect of moistening the cotton around the wires.
The drum with its charge of cable is then placed in a proper vulcanizing vessel.
The drum is slowly revolved during vulcanization in order that the desired effect
may be produced upon all parts of the cable and especially to prevent any unequal
settling of the parts by gravity, which might impair the symmetry of the cable
and produce inequalities in thickness in the insulating covering of the body of
conducting wires. The heat is produced by steam at a temperature of 250 degrees
Fahrenheit for forty minutes.
A suitable An improved apparatus constructed according to the present invention for
reeling the cable or single covered wire for vulcanizing the envelope is represented in
Figures 4, 5 and 6.
This apparatus is constructed with a reel 21, of light wrought iron, of such size
as the quantity of covered wire or cable to be treated at once, may require.

page_text: A reel twelve feet long and four feet in diameter will. hold about two miles of
wire, laid on in three courses.
A shaft 22; extends through the rear end 23 of the vulcanizing, vessel 24 which
is provided with a stuffing box 25. The shaft 22, has on the inside of the vessel a
clutch 26, and is provided on the outside with gearing 27, by means of which a
slow rotary motion may be given to the shaft.
The shaft 28 of the reel 21 is also provided with a clutch 29, at the end. When
the reel is charged with a desired quantity of covered conductor or cable C, it is
placed in the vulcanizing vessel 24.
To facilitate the introduction and removal of the reel and its rotation while in
the vulcanizing vessel it is mounted in bearings in a carriage 31 having small
wheels or rollers 32 running on corresponding rails 33 in the vessel.
The clutches 26 and 29, on the shafts 22 and 28 lock together when they meet.
The door or cover 34 of the vessel is closed, and the reel inside is set in rotary
motion by means of the shaft 22 and its gearing. The reel should make only three
or four revolutions per minute.
In the common mode of embedding covered wire in soapstone during vulcaniza-
tion the wire is not only subject to dislocation by the effect of gravity but the
longitudinal expansion of the conductor by heat during vulcanization is an
additional and very serious cause of dislocation of the conductor from the centre
of the covering.
With apparatus constructed according to the present improvement the covered
conductor is by the rotation of the reel continually changed in its position so far as
the weight or gravity of the conductor is concerned.
Hence the weight of the conductor on its soft covering cannot gradually press it
aside as if it rested quietly; because the rotation of the reel brings the conductor
in a different position by every inch of rotary motion.
Furthermore the metallic conductor has freedom for longitudinal expansion;
being spirally and loosely wound on a reel which is kept in motion in the
same direction as the conductor is wound; the expansion is thus gradually
taken up by the slow rotary motion of the reel, as the heat lengthens the
conductor.
The drum, with the cable coiled upon it being removed from the vulcanizer we
have a cable combining two valuable features to wit; (I) a hollow flexible centre
with numerous openings in its walls, and (II) a number of conducting wires each
separated from the rest by cotton, but all of them surrounded and firmly held
together by an envelope which serves not only as an outside insulator for the
conductors but also as an exceedingly flexible and absolutely waterproof covering
made still more impervious by a layer of metal foil which surrounds and tightly
envelops it, and it is further protected by a double layer of tape.
The next step in the process is to cover the cable with a metal armour to protect
it against mechanical injury and to prevent any rupture or distortion of the
insulating envelope around the body of conducting wires in the operation of
introducing insulating material in a melted state and under high pressure, as
hereinafter explained.
The metal armour is made double in two layers of wire of different thicknesses
applied in the following manner, specially devised to combine flexibility with
effectual protection. The first shield or armour 10, consists of a number of wires,
say about N° 14 Stubb's gauge, all wound at once spirally round the cable making
one turn to about every foot, laid closely enough to cover the surface of the cable
completely. The first armour is succeeded by a second one 11; consisting of two
heavier wires of about one-eighth of an inch in diameter. These two wires are
wound side by side, over the first armour in regular spiral turns, covering the
cable solidly and completely, but nevertheless making a very flexible cable. This
double armour serves two very important purposes, as stated above.
When the cable is armoured, the interior space left between the wires, cotton

page_text: and covering is filled with a good insulating material 12 which will become fluid
by heat and congeal at a temperature of about 140° Fahrenheit..
For this filling paraffine or ozocerite or rosin may be used; a good mixture for
the purpose consists of two parts ozocerite with two parts rosin, and one part.
india rubber dissolved in benzine and mixed with the ozocerite and rosin when melted.
The filling of the cable with said mixture is accomplished in the following
The cable C, is wound on a large drum D, as illustrated in Figure 7 and
one end of the cable is provided with a proper metallic coupling 13.
manner.
The coupling 13 is so arranged as to quickly and perfectly connect the hollow
core of the cable with a nozzle 14 and thus with either of the supply pipes 15, 16
from two force pumps 17, 18 the first being for oil and the other for the liquid
insulating material. The other end of the cable is arranged to discharge into the
tank 19 containing oil heated to at least 250° Fahrenheit.
The hot oil is forced through the hollow cable to heat up the wires and cotton
and carry off all air and moisture.
This is kept up for about half an hour, then the oil is shut off. The pipe 16 is
then opened and the force pump 18 which is connected with a vessel 20 containing
a supply of melted wax or fusible insulating compound is put in operation and the
interior of the cable is completely filled with the melted insulating material.
Pressure is applied to the melted material by means of the force pump which may
be brought to about 200 lbs. to the square inch so as to make sure that the melted
material will penetrate into every interstice and pore which may exist between
the wires, threads of cotton and the outside covering.
For this purpose a
coupling 13 and nozzle with a cock 13b may be applied to the discharge end of
the cable. The cable is then allowed to cool off to solidify the wax or other
insulating body and is ready for use.
If the cable be designed for aerial use, where lightness is a desideratum, a strong
hemp cover is substituted for the metal armour for the purpose of preventing the
bursting of the rubber envelope by internal pressure and protecting the cable from
external injury.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that I make no
claim to the broad feature of winding the insulated cable or conductor upon a reel
to which rotary motion is given during the vulcanizing process nor do I claim broadly
the use of a hollow perforated flexible metallic core for an electric cable nor filling the
same with wax or other insulating material but what I claim is :-
1. The combination of the hollow spiral core, 1, insulated conducting wires 3
impervious envelope 6, and a filling of wax or other fusible insulating material.
2. The combination of a flexible spiral hollow core adapted to permit the passage of
melted insulating material, covered wires surrounding the said core and an
envelope composed of insulating and fibrous material, and sheet metal, the fibrous
material being united to the insulating envelope in process of vulcanization and
preventing cohesion between the same and the covers of the individual wires.
3. The protecting armour consisting of diversely wound spiral wires 10, 11, as
explained, in combination with the hollow spiral core 1, covered wires 3 and insulating
envelope 6 as and for the purposes set forth.
4. The electric cable herein described consisting of the hollow spiral flexible core 1
adapted to permit the passage of melted insulating material, the covered wires 3,
surrounding said core, the impervious envelope 6, 7, 8 surrounding said wires, the
flexible armour 10, 11, and the fusible non-conducting filling 12, as and for the
purposes set forth.
5. The apparatus for vulcanizing insulating envelopes of electrical conductors
or cables, consisting essentially of a vulcanizing chamber, a reel for currying the
covered conductor and-gearing for rotating the reel and its charge during the
✓ process of vulcanization; us explained.

page_text: G. 5. The combination of a vulcanizing vessel having a shaft and gearing for
rotating said shaft and a reel mounted on a carriage and provided with a clutch
for connecting it with the shaft and gearing so as to receive rotation therefrom as
explained.
7. The process of vulcanizing the insulating envelope of electric conductors or
cables, the same consisting in winding the covered conductor or cable on a reel or
drum and slowly rotating the same while in the vulcanizing vessel und during the
process of vulcanization, substantially as set forth.
6. The process of making an electric conducting cable, the same consisting in
laying the conducting wires around a hollow spiral core adapted for the forcing
through it of insulating material in a melted state, covering the said wires with an
impervious envelope of insulating material and subsequently filling the interstices
between the conducting wires, envelope and spiral core with insulating material forced
in in a melted state as explained.
A. 7. The process of making an electric conducting cable, the same consisting in
laying the conducting wires around a hollow spiral core adapted for the forcing
through it of insulating material in a melted state, covering the said wires with an
envelope of vulcanizable material, vulcanizing or partially vulcanizing the envelope
by moist heat applied to the outside only and excluded from the interior, and then
forcing into the hollow spiral core a body of insulating material in a melted state to
fill the interstices, substantially as set forth.
10. S. The process of making an electric conducting cable, the same consisting in
laying covered conducting wires around a hollow spiral core adapted for the
passing through its walls of material in a melted or semi-liquid state, enveloping the
coil or body of conducting wires with vulcanizable material separated from them
by fibrous material to prevent cohesion, then vulcanizing or partially vulcanizing the
envelope and subsequently filling the interstices between the covered wires, envelope
and hollow spiral core with material forced in, in a melted or semi-liquid state
through the hollow spiral core.
19. The process of making an electric conducting cable, the same consisting in
laying conducting wires around a central hollow spiral core adapted to permit the
passage through its walls of liquid or semi-liquid matter, covering the body of
conducting wires with an impervious envelope, surrounding this with a spiral
armour of wire for the purposes of protecting the cable against mechanical injury
and resisting internal pressure, and then forcing into the hollow spiral core and out
through the walls thereof melted or semi-liquid matter to fill the interstices
between the conducting wires, envelope and hollow spiral core.
12. 10. The process of making an electric conducting cable, the same consisting
in wrapping insulated conducting wires around a hollow spiral core, enveloping the
body of wires in a sheet of vulcanizable material, and subsequently vulcanizing
the same by moist heat applied to the outside only and excluded from the interior.
13. 11. The process of making electric cables substantially as herein described, the
same consisting in laying any desirable number of conducting wires with fibrous
coverings around a hollow spiral core having passages in its walls, enveloping the said
body of conductors in an impervious envelope, forcing heated liquid through thes
cable to remove the air and heat the interior, and subsequently forcing in
insulating material in a melted state to fill the interstices between the conducting
wires.
14. 12. The process herein described for insulating wires in electric cables, the same
consisting in forcing through a hollow cable a current of heated oil to heat the
interior and expel air therefrom, and then forcing in a body of melted insulating
material to displace the oil, as explained.
15. 13. The apparatus for filling hollow electric cables, consisting of one or more
forcing pumps, separate tanks for containing heated oil and melted insulating wax
or like material and suitable pipe connections, couplings and stop cocks to permit
the injection of hot oil and melted wax, successively, as explained.

page_text: 16. 14. The combination of the reel D, a cable C coiled thereon, a forcing pump 18
tanks 19 and 20, respectively for oil and wax or the like and suitable pipe
connections and stop cocks to enable the successive injection of oil and insulating
material into the cable as explained.
17. 15. The combination of the tanks 19 and 20, pumps 17 and 18 and pipes 14,
15, 16, provided with suitable stop cocks and couplings, substantially as and for
the purposes set forth.