IMPROVEMENTS IN ELECTRICAL INSULATED WIRES AND CONDUCTORS, AND IN THE MEANS OF INSULATION OF THE SAME."
Year: 1881

page_text: LETTERS PATENT to Samuel Joseph Mackie, of Linden Grove, Peckham, in the
County of Surrey, Civil Engineer, for an Invention of "IMPROVEMENTS IN
ELECTRICAL INSULATED WIRES AND CONDUCTORS, AND IN THE MEANS OF
INSULATION OF THE SAME."
PROVISIONAL SPECIFICATION left by the said Samuel Joseph Mackie at
the Office of the Commissioners of Patents on the 11th June 1881.
SAMUEL JOSEPH MACKIE, of Linden Grove, Peckham, in the County of Surrey,
Civil Engineer. "IMPROVEMENTS IN ELECTRICAL INSULATED WIRES AND
CONDUCTORS, AND IN THE MEANS OF INSULATION OF THE SAME."
Hitherto conducting wires have been insulated by covering them with gutta-
percha and other more or less elastic substances, or as in the case of small wires for
instruments and indoor service, by winding round them fine cords of silk or cotton
only in close short lays. In rough underground work and other exposed services
the gutta-percha and such like coverings are liable to be cut and abraded, and by
perishing to shrivel and crack, whereby the insulation of the wires is injured or
destroyed. The wires of large cables have been armoured by the strands of the
actual cables of which they form the cores.
Now my Invention applies more particularly to single wires, double wires, and
cores of small dimensions, although it is applicable also to cores of larger or of any
dimensions. It consists in insulating the wire or wires by serving it or them with
flat servings of jute, hemp, or other yarns, and saturating and combining the fibres
of the same with the insulating material or compound so that the insulating
coatings become so intimately combined together as to form a practically homo-
geneous substance. Wires so protected may be taped with one or more internal or
structural tapings, and with a final external taping, and all these or any of them
may be combined with the insulating material or compound; or the exterior taping
or surface of the external juting may be waterproofed or insulated by some other
special material.
By combining the fibres of the yarn servings and the tapings with the insulating
material or compound, the insulating covering is most materially strengthened and

page_text: toughened, and the cracking and shrivelling prevented, especially cutting by stones
and abrasion by rough surfaces is well resisted, strength being also given to the
entire cord which enables it to endure greater strains without extension or
fracture.
For electrical firing wires and other purposes the insulated wires prepared as
above may be partially covered with simple jute or other yarn servings to protect
the wires still further and cheaply from the cuttings by stones or otherwise in
stemming charges in the bore-holes, and for field telegraphs and other similar
services where traffic may take place over the wires similar servings of jute or
other servings may be made over the insulated wire-core.
The jutings or other yarn-coverings and tapings are put over the wire or wires
of the metallic conductor with tho insulating material or compound in the following
way: The wire or metallic core is wound on a drum, it is thence passed through
an iron tank containing the insulating material or compound which is melted by a
gas-flamo beneath the tank. The wire or metallic conductor is thus itself first
coated with the insulating material or compound; it passes now into the yarn-
covering and taping machine by an orifice in a disc carrying a number of bobbins
on which the jute or other fibrous yarn is wound. This disc revolves with its
bobbins and so covers the wire or metallic conductor as it passes with a flat serving.
of jute or other yarns, generally from four to eight or more at a time, like the
woof of a tape without the weft. The wire or metallic conductor so served is next
passed through another disc carrying a number of bobbins which serve the wire or
metallic conductor with a second serving of jute or other fibrous yarns, this serving
being flat similarly to the first serving, but put on in a contrary direction so as to
cross the spirals of the servings over each other. The lay or ply of the servings I
prefer to have made as long as desirable, the general variation being from one turn
in half an inch to one turn in four and a half inches. The cord now consisting of
its central wire or metallic conductor with its several servings of jute or other
yarn is next passed through a tank with a long iron tube attached to it containing
melted insulating material or compound, and the fibrous servings are thus com-
pletely saturated with the insulating material or compound. This cord is next
passed through another disc with a central slotted barrel. The disc carries a
bobbin wound with tape upon an adjustable arm. The tape is passed by a guide
through the slot and attached to the wire-cord or metallic conductor-cord, and then
by the revolution of the disc and barrel the cord is covered by the taping. This
taping may be left as it is for the external covering, or it may be again passed
through the insulating material or compound, or be covered by other coverings of
jute or other yarns and other tapings either passed through the insulating material
or compound or not according to requirements. At each stage of its progress the
cord is passed through dies hot or cold, fixed or revolving, as best adapted to
secure equality of diameter, firmness of structure, and homogeneity of substance by
squeezing the whole body of the materials compactly together. Grooved rolls may
also be used instead of dies. At its final stage the cord is passed through powdered
glass or other suitable material in order to solidify the insulating material or
compound, or otherwise harden its surface and prevent adhesion of the coils when
the cord is wound off, or otherwise in handling.
Powdered glass is sometimes mixed with the insulating material to give solidity
to its mass and also to cheapen the insulating material. Lamp black and other
coloring matters may be likewise used, as also sulphur, cement, and the like.
In saturating the jute or other servings and tapings I prefer to keep the
insulating material especially if of the nature of gutta-percha or other plastic or
semifluid compounds under pressure, and I do so by forcing the insulating
compound into the saturating tubes or otherwise by two wheel-like drums working
into each other, and within a sufficiently closed chamber or receptacle connected
with the tank containing the insulating compound, and to close the end of the
return pipe, bringing back the unused excess of compound by a weighted valve
like the safety-valve of a steam boiler or other suitable means. In cases when the

page_text: insulating composition is fluid I prefer to use ordinary force pumps for putting
pressure upon it. I also prefer in some cases to varnish the exterior of the
conductor cord or rope with shell-lac varnish, collodion, or gelatine saturated with
chromate or bi-chromate of potash with or without alum or other materials.
For the tapings there may be substituted wrappings of metal foil, or thin metal,
or metal gauze, and in some cases I prefer to substitute braiding for taping either
entirely or in part, using a braiding machine for covering the jute or other servings
instead of the taping machine as above described.
For the insulating material a very good compound may be made of gutta-percha,
Stockholm-tar, and rosin, or of shellac varnish with or without lamp-black or other
materials, or of collodion with or without other materials, or of gelatine with
lamp-black or other materials rendered waterproof by chromate of potash or
otherwise.
For the further protection of the insulated conductors they may be placed in my
C-shaped or ordinary iron or other tubes, and compositions of powdered glass and
sulphur, cement, plaster of Paris or bitumen with or without powdered glass
or lamp-black or other suitable material run in the tubes around the conductors.
Compound insulated taped or braided conductor-cords consisting of two separate
insulated wires or cores bound together in one cord or of many separate wires can
be made by the means above described, or for electrical firing or other purposes
one insulated wire or core and one uninsulated wire or core, or several insulated
wires or cores and several uninsulated wires or cores can be similarly combined in
one cord.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Samuel Joseph Mackie in the Groat Seal Patent Office on the
10th December 1881.
SAMUEL JOSEPH MACKIE, of Linden Grove, Peckham, in the County of
Surrey, Civil Enginoer. "IMPROVEMENTS IN ELECTRICAL INSULATED WIRES AND
CONDUCTORS, AND IN THE MEANS OF INSULATION OF THE SAME."
Hitherto electrical conducting wires or cores have been insulated by coating
them with gutta-percha, india-rubber, and other more or less elastic substances or
compounds; or as in the case of small wires for instruments and for indoor services,
by winding round them fine cords of silk or cotton in close short lays. In rough
underground work and other exposed services the gutta-percha and such like
coatings are liable to be cut and abraded, and by perishing to shrivel and crack,
whereby the insulation of the wires is injured or destroyed. The wires of largo
cables have been armoured by the strands of the actual cables of which they form
the cores.
Now my Invention has for its purpose to preserve, protect, and cheapen
the insulation of electrical conducting wires or cores, and it applies more
particularly to single wires, double wires, and cores of small dimensions, although
it is applicable also to cores of larger or of any dimensions. It consists in
insulating the wire, wires, or core constituting the electrical conductor by serving or
covering it or them with fat servings of jute, hemp, or other yarns, and saturating
such yarns with insulating materials or compound so that the insulating material,
materials, or compound, and the fibres of the jute or other yarns used in the
coatings or coverings become so intimately combined together as to form a
practically homogeneous substance. Conducting wires and cores thus insulated or
insulated in the ordinary or any other way may be further protected by being
again taped or served with one or more tapings or servings of yarn, and finally
enclosed in an external taping or braiding; and all or any of theso tapings, servings,
or braidings may be combined or not as required with the insulating material or
compound. Or the external coverings or any of them may be waterproofed instead
of saturated with insulating material or compound. By thus combining the fibres
of the yarn servings, the tapings and the braidings, with the insulating material
or compound, the insulating covering of the conducting wire or core is most
materially strengthened and toughened, and cracking and shrivelling is prevented,
and especially cutting by stones, and abrasion by rough surfaces is well resisted,
strength being given to the whole cord which enables it to endure greater strains
without serious extension or fracture. For electrical firing of mines and explosive
charges and other purposes. the insulated wires or cores propared as above may be
further covered for their protection with simple jute or other yarn servings, or by
tapings or braidings. These additional servings or coverings, or any of them, may
be saturated with insulating material or compound to increase the insulation of the
conducting wire or core, or waterproofed by any means, but preferably by gelatine
combined with bichromate of potash or other similar chemical substance.
The mode in which I prefer to manufacture single wire insulated cores or cords
is as follows:-The wire or metallic conducting core is wound on a drum, and one
end is then passed through the operating apparatus to a taking-off pulley, and
afterwards to a receiving drum, upon which the finished article is wound as it is
completed, the conducting wire or core being continuously drawn forward by some
motive power as the work proceeds. The first part of the apparatus is a tank or
receptacle containing the insulating material or compound, which is melted by a
gas-Hame beneath the tank, or by other convenient means, unless a naturally fluid
or plastic material or compound be employed. The conducting wire or coro is

page_text: passed into and out of this receptacle through dies or orifices of dimensions suitable
to the size of the conductor, and is thus coated with the insulating material or
compound. The wire or core thus partially insulated passes next into the yarn-
covering and taping machine by an orifice in a disc, which carries a number of
bobbins on which the jute or other fibrous yarn is wound. The ends of theso
yarns are fastened to the conducting wire or core partly insulated as above, and
being brought through a number of pins with eyes corresponding to the number of
bobbins each yarn is consecutively wound round the wire or core by the rotation
of the disc as the wire or core is drawn continuously forward through the
apparatus. The wire or core so coated with insulating material or compound, and
with one serving of jute or other yarn again passes a second disc similarly provided
with bobbins of yarn, and a circle of pins with eyes for the yarns to pass through
to serve the wire or conducting core with a second serving of yarn. Between thoso
revolving discs a tank of insulating material or compound is provided for the
saturation of the fibres of the yarn sorvings. Each of these discs works in a
direction contrary to the other, so that the spiral directions of the yarns in the two
coverings may cross each other and prevent unravelling. At such stage the cord
formed by the conducting wire or core and its respective coverings is passed
through tanks of insulating material or compound and through dies of suitable
dimensions. The cord in this stage next passes through a disc furnished with a
revolving slotted barrel and an arm for carrying a bobbin of tape. The end of
the tape being secured to the conductor-cord through the slot of the barrel, the
cord is finally covered by an external taping when the disc is revolved. The taped
conductor-cord can be now passed through a tank of insulating material, and then.
through the long iron-pipe connected with the tank, and kept heated by gas flamo
or other convenient means. Finally the cord so far completed is passed through
finishing dies to assure its correct dimensions and the perfect combination of the
constituent materials, and then well dusted with powdered glass by a revolving
barrel it is wound off on the receiving drum. In all cases a sufficient head of tho
insulating compound or material is kept in the tanks to saturate the fibres of the
yarn, or mechanical or other means are applied to insure this end. The insulating
material or compound is also made sufficiently fluid by heat or otherwise to aid this
operation. Pressure by means of the dies or by grooved rollers can be also applied
in all or any of the stages to insure this saturation of the fibres, and the general
combination of the materials of the conductor-cord. Tapings or braidings also may
be substituted for the simple yarn-servings in any of the stages of the production
of the conductor-cord, according as needful for the particular practical service to
which the article produced is to be applied.
For the insulating material a very good compound may be made of gutta-percha,
Stockholm tar, and rosin in equal weights, and mixed with a proportion of
powdered glass according to the degree of solidification required for the purpose
required. Shell-lac varnish with or without lamp-black or other material, or
collodion with or without powdered glass, or gelatine with bichromate of potash
or other like chemical, and with or without powdered glass, may also be well
employed.
Having described the mode in which I prefer to manufacture single wire
conductor-cords, I now describe some of the ways in which I produce double wiro
and compound cores. For double wire conductor-cords I place two single-wire
conductor cords as above together, and serve the two with an external covering or
coverings of tape, or of yarn, or of braiding, or any of these in the way required.
Sometimes I place one single conductor-cord as above, and one uninsulated copper
wire or core beside it, and then tape, braid, or yarn the two together in a similar
way saturating the fibres of the external coverings or covering; in this case, the
same as those in the single wire cords any of the combinations or substitutions of
waterproofing for insulating material or compounds can be made in the composite
cords as in the single conductor-cords. The details of my process for saturating
the fibres of the yarn and consolidating the insulating material or compound with

page_text: them can be performed by separate apparatus for the various stages, instead of
continuously, as described above.
For the protection of the insulated cord-conductors they may be placed in my
C-shaped or in ordinary iron or other tubes and compositions of powdered glass
and sulphur, cement, plaster of Paris, or bitumen, with or without powdered glass
or other substance being run into the tubes around the cord-conductors.
Compound insulated taped, yarned, or braided conductor-cords consisting of
separate insulated wires or cores may be bound together in one cord or rope; or
one cord or rope containing many separate wires or conductors can be made by the
means above described. Cables of large size can also be constructed in these or
other ways.
What I claim is,--
I. The production of a substantially insulated electrical conducting cord by
winding round or serving the conducting wire or core with more or less open and
flat servings of jute or other yarns saturated with insulating material or compound,
and pressed into a practically homogeneous covering, substantially as described.
II. The combination of ordinary tapings and braidings with my process, and the
production of compound cords or ropes of such conducting cords above described,
either combined or not with ordinary tapings or braidings, and which compound
cords or ropes may contain two or more wires, or two or more such cords, or be
formed with one or more conducting insulated cords, and one or more insulated
wires or conductors, the combination being enclosed in a taped, yarned, or braided
external covering insulated or water proofed or otherwise, substantially as
described.
III. The process and apparatus for the production of such insulated conducting
cords, single or compound, substantially as described, and, the various parts and
portions thereof for the purposes of my Invention.
IV. The use of powdered glass as an ingredient in the insulating material or
compound and in my process generally.
V. The protection of my insulated conducting cords and of ordinary cores and
conductors by the servings of jute and other yarns employed in my process and as
for my conducting cords, substantially as described.
In witness whereof, I, the said Samuel Joseph Mackie, have herounto set
my hand and seal, this Tenth day of December, One thousand eight
hundred and eighty one.
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