Improvements in Flexibly Insulated Conductors, and Methods of, and Apparatus for Making the same and other Continuously Coated Extended Lengths of Material.
Year: 1897

page_text: Date of Application, 20th July, 1897-Accepted, 11th Sept.,
1897
"
COMPLETE SPECIFICATION.
Improvements in Flexibly Insulated Conductors, and Methods of, and
Apparatus for Making the same and other Continuously Coated
Extended Lengths of Material.
'
I, JOHN HALL KELMAN of Pittsfield, in the County of Berkshire, and State
of Massachusetts, United States of America, Mechanical Engineer, 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 improvement in Conductors relates to the art of electrical conductors used
in systems for the transmission of electrical energy, and in apparatus for the
It has for its object
generation, transformation and conversion of such energy.
to furnish a safe and reliable insulated conductor, on which the insulation is of
little bulk, of high ohmic resistance, and of high dielectric strengtli, and which
is particularly useful in the construction of generators, transformers, and motors
and devices generally, in which insulated conductors are used in similar relation.
My improvements in methods and apparatus relate to the art of manufacturing
electrical conductors and other continuous extended lengths of material having
insulated coatings, and has for its object to provide an efficient and convenient
means and methods of making and applying such coatings.
The following is a description of my improvements, reference being had to the
accompanying drawings.
of
or
other
Heretofore it has been customary to form coils of flexibly insulated conductors
cotton
a covering of
or silk fibre,
by weaving upon the conductor
a covering
fibrous material,
or by applying
paper..
sometimes saturated with paint or parafine or intermingled with a rubber, which
is subsequently vulcanized. Of these insulated conductors all have their various
objectionable features. The insulation upon all of them is bulky and of compara-
tively low ohmic resistance and dielectric strength, is full of faults which lessen
the dielectric strength and permit deterioration, and cannot be advantageously
applied to conductors of all shapes. Furthermore, when cotton or silk is used
in direct contact with the wire, there is apt to be some salt or acid present, which,
when copper is used as the conductor, as is ordinarily the case, attacks the metal,
forming salts of copper which penetrates the covering and reduces its insulating
powers.
It has also been customary to form insulated coils or conductors where the con-
ductor is coiled before it is insulated, and then to have the coil and the parts
thereof covered by a pyroinsulation such as vitreous enamel which surrounds
and embeds the conductor, making it an integral and inflexible mass, a coil of
flexibly insulated conductor, and not a coil of flexible conductor.
In contradistinction to the coil of insulated conductor above referred to, the
insulated conductor of my invention has none of the disadvantages which I have
mentioned, but furnishes a conductor with a flexible insulation which is uniform
and of little bulk, and is of high ohmic resistance and dielectric strength, and
which has practically none of the "faults," and can be easily and advantageously

page_text: Fig. 1, represents a coil of flexibly insulated electrical conductor, embodying my
invention in conductors.
Fig. 2, represents a part of a single coil of the same on an enlarged scale, partly
in section.
The remaining figures show an apparatus for carrying out the method by which
I make coils embodying my invention in conductors.
Fig. 3, is a section of the apparatus showing its various parts somewhat
diagrammatical.
Fig. 4, is a vertical section of the ozone generator S on the line 1-1, showing
its interior plates.
Referring more specifically to the drawings, A represents a coil of flexibly
insulated conductor embodying my invention. B represents the metallic portion
of a part of the same on an enlarged scale. Crepresents a coating of tin applied
to the copper surface of the portion B, and C represents the insulating covering
upon the same. In its preferred form the insulated conductor consists of a copper
or similar metallic conductor having a tinned surface covered by an ozone
hardened coating of linseed oil or other similar linseed oil varnish.
The material I prefer to use for the covering C² consists of ordinary boiled
linseed oil, the oil can be thinned by turpentine, if necessary. I have also used a
baking japan, having boiled linseed oil as its base. A formula for making such
a baking japan is as follows: 100 pounds of asphaltum, gum, 10 Gallons of boiled
linseed oil, 5 pounds of gum anime, 15 gallons of turpentine, and additional
turpentine sufficient to keep the mixture at the necessary thickness for the desired
coat. Any commercial linseed oil baking japan can however be used. The more
flexible and tough when hardened, the better. Pure linseed oil, or other baking
linseed oil varnishes, such as japan, I shall hereafter refer to as linseed oil
varnishes.
I apply this covering in the manner and by the apparatus hereinafter described.
In ne drawing, Fig. 3, D represents a continuous length of the electrical con-
ductor or other material to be coated, mounted upon a reel E. In case it consists
of a copper conductor, it is preferably tinned and passes as a wire I)¹ from the
coil around a pulley F in a closed chamber O and up through an orifice g in a
plug or projection G as the bottom of the vessel G containing a bath of the
material for the insulating covering, and preferably having a cover g! It then
passes through the orifice H into a hardening chamber I. This chamber I is
built to retain heat and to keep out as much light, either natural or artificial
as possible, since, by my process, the best insulation is made when all light is
absent from both the hardening chamber I and the chamber 0. In this chamber I,
which is the heated hardening chamber, the wire D' after being coated by passing
through the bath in the vessel G is subjected to the action of ozone or heat, or
both, which hardens the material adhering to the wire after its passages through the
bath. It then passes through the orifice J and over the pulley K, after which
it passes over the idle pulley L to the reel M. The pulley is encircled part
way by the wire, and has a friction brake N which makes the pulley F act as

page_text: a tension upon, as well as a guide for, the wire D'. The pulley is made to revolve
at a slow rate of speed by power from some convenient source, as P, and draws the
wire D' upward through the chamber I. The reel M is made to revolve sufficiently
fast to take up the wire as it comes to it, being driven through some convenient
source of power as P1, by a friction connection Q, which permits it to adjust its
rotation to the speed of the wire.
Directly below the chamber 1 is the closed chamber O, which in practice is
preferably large enough to permit a man to enter. Within this chamber is the
vessel G containing the bath, a suitable composition for which I have heretofore
mentioned. A bath of ordinary linseed oil makes a very satisfactory insulation.
The orifice through the small plug or projection G is of the size to permit
the free passage of the wire D'. In insulating the conductor, in order to maintain
the bath in proper condition, the temperature of the contents of the vessel G is
maintained at about 200° Fahrenheit. This is preferably done by electric heating
device T3, which also heats the conductor T somewhat before it reaches the bath.
The chamber I when ozone is used is kept saturated or almost so with ozone,
supplied by ducts R' R' from the ozone generator S. This chamber I is kept
heated so that at the bottom the temperature is about 250° Fahrenheit and at
the top about 375°. The chamber is also preferably supplied with ozone by
the ducts R, so that the coating is acted on somewhat before it reaches the higher
temperature of the chamber I. The heating is preferably accomplished by the
joint action of steam heaters T T and electrical heaters T2 T2, which latter as well
as the heater T are controlled by switches, preferably by manual switches W,
together with automatic thermostatic switches W', so as to automatically regulate
the temperature. By this means, if the difference in temperature between the top
and the bottom of the chamber I, due to the tendency of the hot air to ascend,
is not that desired, the heaters at the top can be adjusted so as to make the upper
part of the chamber still hotter. The length of the chamber I is governed by
the length of the conductor to be coated that can be drawn by the pulley K from
the reel E without undue stretching. A greater length of chamber permits greater
speed of the conductor without shortening the time during which it is subjected
to the action in the hardening chamber.
The ozone generator I have used, generates a sufficient quantity of ozone and
consists of a chamber Y, containing two sets of opposing conduction plates u u',
separated by a thin coating of dielectric V, such as a coating of enamel or japan
on their opposing surfaces. The alternate plates are connected respectively to
the terminals of a circuit of high alternating potential.
A fan Z or similar means
is provided for drawing or forcing a current of air between the plates u u¹ and
into the ozone chamber I. The air as it passes between the plates u u¹ is
acted upon by the electrical discharge and part of it converted into ozone. This
ozonized air then passes into the chambers I and O, escaping at the orifices
through which the wire passes, and at other points, if necessary. As shown, the
generator X through the transformers Z Z supplies electricity to the ozone
generator S and the heaters Tº Tº and T³.
wire
The action upon the covering on the wire in the heated ozone chamber is
as follows: The heat soon volatilizes any volatile parts of the coating, while at
the same time the ozone rendered more active by the heat, oxidizes the linseed
oil contained therein, in the absence of any light. This process of oxidation
being of a different nature from evaporation, leaves no pores in the covering,
but on the contrary, makes a covering without pores and of a tough,
Hexible and semi-elastic character. As any portion of the now covered
reaches the
upper portion of the hardening chamber I, it is sub-
jected to an increased temperature which tends to still further
harden the covering. The higher degree of heat at the upper part of the chamber
tends to decompose the ozone, but the circulation in the chamber being upward
keeps the upper part supplied with ozone. If it is desired that the covering be
subjected to the action of heat and ozone for a longer period, the conductor may

page_text: be made to traverse the hardening chamber for a second time. The flexibly
insulated conductor after the coating is sufficiently hardened, is reeled, making
the completed coil. Should it be desired to make the insulation thicker than can
be done by passing the conductor through the bath and chanrber but a single time,
the first operation can be repeated upon the flexibly insulated conductor until the
several coatings make the desired thickness. In case the substance to be coated
is such that it will not be injured by a higher degree of heat than that above
named, I may subject it to as much as 450 Fahrenheit. In such a case since
the ozone would be at once decomposed, I omit the ozone and rely only on the heat
for hardening. I may omit the ozone at lower temperatures, and rely upon the
oxidizing action of the air.
When a copper conductor is used, it should, preferably, be tinned before it is
coated. This assists very materially in obtaining a smooth and even coat, as the
insulating material adheres more readily to the tinned surface than it does to the
copper surface. The tinning is done in the ordinary way by any of the ordinary
apparatus for tinning wire now in use. The apparatus above described, to obtain
the best results should be run continuously twenty-four hours a day, new reels
being supplied and joints soldered while in operation. The speed at which the
wire moves should be such that the coating will be well hardened before it leaves
the hardening chamber.
The drawing shows but one wire passing through the chamber I. In practice,
however, as large a number of wires are run through as can be without inter-
ference, to do which the number of reels, pulleys, baths, &c., is increased
accordingly.
The metallic portions of the conductor may be of almost any shape. In case
the apparatus is to be used for making oiled cloth or oiled tape or applying any
linseed oil composition to other continuous lengths, it is only necessary that the
bath be made with the proper material and kept at the proper thickness for the
desired coating, and that the orifices in the projection G and to permit passage
into and out of the chamber I be made to correspond in shape to a section of the
substance to which the material is to be applied, and that continuous lengths
of fabric or other material suitable for the base of the desired product be passed
through the apparatus coated with the material from the bath and exposed with
its coating in the ozone chamber. The process in such cases is the same as that
above described, with the exception of the tinning which is an auxiliary and
preliminary step which may be and preferably is used in the case of coating
with japan or oil, a continuous length of copper conductor for electrical purposes.
The vertical chamber I and the passing of the lengths through it in a vertical
position have an advantage and are preferred since the coating under such cir-
cumstances distributes itself more evenly and smoothly while being acted upon
by the ozone.
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. A flexibly insulated conductor for electrical purposes, consisting an extended
length of electric conductor and a coating thereon of oxidized oil varnish such
as linseed oil varnish, substantially as described.
2. A flexibly insulated conductor for electrical purposes consisting of an extended
length of tinned copper conductor, and a coating thereon of linseed oil varnish,
substantially as described.
3. A coil of flexibly insulated conductor for electrical purposes consisting of a
coiled copper wire and a flexible and uniform coating of hardened linseed oil
varnish adhering thereto, the coatings of several turns being separate at the points
of contact, substantially as described.
4. A coil of flexibly insulated conductor for electrical purposes consisting of an

page_text: electrical conductor and a coating of ozone ardened seed oil varnish,
substantially as described.
5. A coil of flexibly insulated conductor for electrical purposes consisting of
a coiled copper conductor having a tinned surface, and a coating of ozone hardened
linseed oil, substantially as described..
6. The process of applying and hardening coatings of japan or other materials
having similar drying qualities to articles of extensive lengths consisting in.
continuously passing a continuous length of the article to be coated through a
bath of the material to be applied. and then through a hardening chamber, and
subjecting succeeding portions of the coated article while in said hardening
chamber to the action of heat of continuously increasing temperature, substantially
as described.
7. The process of applying and hardening coatings of japan or other materials
having similar drying qualities to articles of extensive lengths consisting in
continuously passing a continuous length of the article to be coated through a
hath of the material to be applied, and then through a vertical hardening
chamber and subjecting succeeding portions of the coated article while in a
vertical position to the action of heat of continuously increasing temperature,
substantially as described.
8. The process of applying and hardening coatings of japan or other materials
having similar drying qualities to articles of extensive lengths consisting in
continuously passing a continuous length of the article to be coated through a
bath of the material to be applied, and then through a vertical hardening
chamber and subjecting succeeding portions of the coated article while in a
vertical position to the action of heat of continuously increasing temperature
with ozone, substantially as described.
9. The process of applying and hardening coatings of japan or other materials
having similar drying qualities, to extensive lengths of copper or other similar
electrical conductors, which consists in first tinning said conductor, then passing
it through a bath of the material to be applied and then through a hardening
chamber and subjecting succeeding portions of the coated conductor while within
said hardening chamber to the action of heat, substantially as described.
other
10. An Apparatus for applying and hardening coatings of japan or
materials having similar drying qualities, consisting of 'a vertical hardening
chamber, and means for heating the same, a bath of the material to be applied.
and means for continuously passing extended lengths of the article to be coated
through said bath and vertically through said hardening chamber, whereby
successive portions of the article are coated and the coating hardened while
subjected to the action of heat of continuously increasing temperature, substantially
as described.
11. An apparatus for applying and hardening coatings of japan or other materials
having similar drying qualities, consisting of a vertical light proof ozone
chamber, and means for heating the same, an ozone generator supplying ozone
to said chamber, a bath of the material to be applied and means for continuously
passing extended lengths of the article to be coated through said bath
vertically through said ozone chamber, whereby successive portions of the article
are coated and the coating hardened while subjected to the action of ozone and
heat, substantially as described.
and