Improvements in the Insulation and Laying of Electrical Conductors and in Apparatus for that Purpose.
Year: 1887

page_text: Date of Application, 11th May, 1887
Complete Left, 9th Feb., 1888
Complete Accepted, 9th Mar., 1888
Improvements in the Insulation and Laying of Electrical Conductors
and in Apparatus for that Purpose.
I, DONALD NICOLL of Buckingham Street, Strand in the City of Westminster,
Civil Engineer do hereby declare the nature of this invention to be as follows:-
For effecting the insulation of electrical conductors I form a compound of gas pitch
and cotton foots pitch in about equal quantities, or, for economy's sake a larger pro-
portion of the gas pitch may be used, when great flexibility is not required. I
incorporate these ingredients at a uniform and moderate temperature, for which
purpose I prefer to employ a bath or cauldron having a jacket containing steam or
heated air. The bath may contain revolving stirrers that may be driven from a hot
air engine, the waste hot air from which may be utilised for heating the wire
conductors before coating.
The hot compound thus produced is introduced into a cylinder where it is subjected
to pressure by a piston or plunger so as to force it through a tube of small
diameter, while at the same time the wire to be coated is passed in a tightly stretched
condition through the cylinder and tube, so that the wire issues from the end of such
tube with a coating of the insulating compound thereon. The wire may be con-
veniently passed through the tubular rod of the said piston and through a guide fixed
in the cylinder so as to ensure its passing into the tube in a central position. The
tube through which the wire and compound pass is by preference enclosed in a
refrigerator or tank through which a current of cold water is caused to flow, so that.
the coating will have become more or less solid as it issued with the wire from the
tube. In some cases I also provide the wire with an outer coating of powdered mica
as it passes through the tube, for which purpose two or more conduits may be made
to enter the tube just below where it joins the cylinder containing the compound,
such conduits leading up through the refrigerating tank and being connected to
hoppers containing the powdered mica, which is discharged in regulated quantities
into the tube by means of revolving scoop wheels or other suitable known
contrivances.
The coated wire on issuing from the tube is then led, if necessary, through a
cooling chamber in order to further solidify the coating, and then wound upon a

page_text: drum rotated by power so
as to draw the wire through the above described
coating apparatus, the speed of the wire being made to correspond with the speed
at which the compound is forced through the tube by the piston.
When the coated wire requires to be taped, this is effected in the usual way while
the wire is passing from the coating apparatus to the winding drum; when the
wires are to be covered with jute fibre I by preference heat these before applying
them, so as to cause them to adhere to the compound.
When treating long lengths of wires that are to be used for less permanent
purposes, the above described coating apparatus may be dispensed with and the wire
be passed directly through the bath containing the compound, from which it is led to
a cooling chamber, and when the coating is sufficiently solid I twist over it heated
jute. This will usually suffice when the conductors are to be laid in sandy soils, but
to protect the conductors from, damp or when placed in wooden troughs, I imbed
them in a compound which I call Nicholls Compound No. 2, consisting of about four
parts by weight of the first described compound mixed with about two parts of
resinous oil, one part of crude petroleum, one part of gas tar and one part of mica;
but I do not bind myself to these proportions as they may vary according to the
quality of the ingredients used.
Or according to another arrangement I employ vertically placed slabs of brick-
earth or other suitable material, having horizontal grooves and placed side by side, so
that the meeting grooves form closed channels in which are contained the conductors,
introduced in proper positions between the slabs before these are placed close together,
the slabs being by preference coated on their meeting surfaces with the above
described compound so as to be united together thereby and form continuous
impervious conduits.
At any required points these conduits are interrupted and "tapping" boxes
inserted, of sufficient length to allow of such an amount of slack to the conductors
being contained therein as may be required for conveniently "tapping" the con-
ductors, or forming branch conductors thereon, leading into dwellings or other
localities that require to be supplied with the electric current. Those " tapping
boxes are closed air-tight, and may be filled with Nicolls compound No. 2 or crude
petroleum oil.
Dead this 11th of M. 1007
وو

page_text: Improvements in the Insulation and Laying of Electrical Conductors
and in Apparatus for that Purpose.
I, DONALD NICOLL of Buckingham Street, Strand, in the City of Westminster,
Civil 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 :-
For effecting the insulation of electrical conductors, I form a compound of gas
pitch and Cotton Foots Pitch, in about equal quantities, or for economy's sake a
larger proportion of the Gas Pitch may be used when great flexibility is not required,
but when it is required, especially for electric lighting in dwellings and sharp angles
have to be passed by my conductors, 1 then use in suitable proportions, some one, or
more than one, of the substances or liquids described in the Specifications of my
Previous Patents viz. 15th Feb. 1866 No. 480, 11th March 1867 No. 694, 31st August
1867 No. 2480, 25th January 1887 No. 1199.
I incorporate these ingredients at a uniform and moderate temperature, for which
purpose I prefer to employ a bath or cauldron having a jacket containing heated
water and steam, or heated air, to the said bath I attach revolving stirrers, that may
be driven from a hot air engine, the waste hot air from which may be utilised for
heating the wire conductors and for other purposes. I prefer to use these cauldrons
or baths with stirring apparatus moved by hand and the whole to be in a portable
form and I prefer to heat the water to form steam by creosote or petroleum oil lamps,
the heat from which is intensified by blasts of compressed air, the said baths or
cauldrons having safety valves which are closed when the apparatus is removed from
the lamps or fire for the purpose of spreading the molten compound round conductors
or wires either in the course of insulating or for covering them when insulated and
placed in continuous troughs as described in my Patent No. 480 dated 15th Feb. 1866.
The use of apparatus thus constructed prevents the insulating compound or conductors
from charring when the latter are laid in troughs or in slabs as hereinafter described
or in slabs or in troughs or in blocks of asphalte as described in my Patent dated
15th February 1866 No. 480 and as the several substances used for insulation are
melted separately, they will blend more easily by being continuously stirred before
being used.
Before heating the wires intended to be insulated I prefer to form a conductor by
a continuous helical coil of one wire wound round another or main wire, in the manner
shewn by the drawing accompanying the Specification of my Patent No. 1199 dated

page_text: 25th January 1887. The application of the said helical coil to the entire length of
my conductors enables me to produce a thicker and more even covering upon the
wire as the convolutions hold the compound in larger quantities than is possible by
using ordinary or smooth wires.
This helical coil largely increases the strength of a conductor when under a great
strain and also its conductivity for any
electrical purpose.
The hot compound produced as above described is into a cylinder where it is
subjected to pressure by a piston or plunger so as to force it through a tube of small
diameter, while at the same time the wire to be coated is passed in a tightly
stretched condition through the cylinder and tube, so that the wire issues from the
end of such tube with a coating of the insulating compound thereon. Fig. 1 of the
accompanying drawings. shews a vertical section of this apparatus, and Fig. 2 a
section on line X X.
The wire may be conveniently passed through the tubular rod C₁ of the weighted
piston Cand through a guide Afixed in the jacketted cylinder A so as to ensure its
passing into the tube G¹ in a central position The tube through which the wire and
compound pass, is by preferonce enclosed in a refrigerator or tank D through which
a current of cold water is caused to flow by pipes D₁ so that the coating will have
become more or less solid as it issues with the wire from the tube. In some cases I
also provide the wire with an outer coating of powdered mica as it passes through the
tube, for which purpose two or more conduits I, I. may be made to enter a chamber G
surrounding the tube G¹ just below where it joins the cylinder containing the com-
pound, such conduits leading up, through the refrigerating tank, and being connected
to a hopper E containing the powdered mica, which is discharged in regulated
quantities into the conduits I and chamber G by means of either revolving scoop
wheels or other suitable known contrivances such as a circulating current of air
produced by a fun F' drawing air from the chamber G through pipe F and propelling
it through pipe F2 into the conduits I. The tube G¹ has slits as shewn through which
the mica in the chamber G can pass on to the surface of the coated wire passing
through.
The coated wire on issuing from the tube is then led, if necessary, through a cooling
chamber in order to further solidify the coating, and then wound upon a drum rotated
by power so as to draw the wire through the above described coating apparatus, the
speed of the wire being made to correspond with the speed at which the compound is
forced through the tube by the piston.
Some part of the foregoing process may be omitted, where a factory is of sufficient
height to allow the molten compound to descend and surround the wire by gravitation
and for it to pass through chambers kept cool by revolving fans. The tubes through
which the wires would thus descend, may be served at two or more stages with fresh
quantities of the molten compound, so as to form a gradually increased coating
which for underground conductors is of importance as tending to diminish induc-
tion and with this object the diameter of the tubes will be gradually enlarged, and
the descent of wires through the tubes be assisted by two grooved wheels moved
usually by band power and placed so as to grasp and gauge the descending wire
between them, a strain thercon being effected by the said wheels revolving in
contrary direction, the revolving drum carrying the wires at the top floor of the
factory will be partially restrained by india rubber bands or other means which will
keep the descending wires in a straight and taut condition.
When the coated wire requires to be taped, this is effected in the usual way while
the wire is passing from the coating apparatus, the coated wires may be covered with
jute fibre or cotton. I by preference heat these before applying them, so as to cause
then to adhere to the compound and I prefer to use a plaiting machine of the nature
described in a drawing accompanying my Specification of 11th March 1867 No. 694
and the conductors may then be coiled for future service.
When treating long lengths of wires to be used for less permanent purposes, the
-above described coating apparatus may be dispensed with and the wire be passed

page_text: directly through the bath containing the compound from which it is led to a cooling
chamber and when the coating is sufficiently solid I gange it and twist over it heated
jute. This will usually suffice when the conductors are to be laid in sandy soils, but
to protect the conductors from damp or when placed in troughs I embed them in a
compound which I call Nicolls' compound No. 2 consisting of about four parts by
weight of the first described compound, mixed with about two parts of resinous
oil, one part of crude petroleum, one part of gas tar and one part of mica, but I do
not bind myself to these proportions as they may vary according to the quality of
the ingredients used.
Or according to another arrangement I employ vertically placed slabs of vitrified
brick earth or other suitable material, by preference asphalte having horizontal
grooves and placed side by side so that the meeting grooves form closed channels in
which are contained the conductors, introduced in proper positions between the slabs,
before these are placed close together, the slabs being by preference coated on their
meeting surfaces with the above described compound so as to be united together
thereby and form continuous conduits.
For laying long lengths of a small number of conductors I prefer to use rectangular
shaped troughs of metal or wood as described in my Patent of 15th February 1866
No. 480 but previously dipped in either of the aforesaid molten compounds and for
the several lengths to be dovetailed into each other so as to receive the said wires in
continuous lengths, and to hold around the same molten compound prepared in the
manner described, and I prefer to cause the conductors before laying same to pass
through a bath of the compound while uncoiling the conductors.
For laying torpedo conductors or submarine mines, or deep sea cables I do the like
and prefer to use Nicoll's compound No. 2 as I find the mica used therein will
preserve the cable from the attacks of the teredo, also on shore, the presence of mica
in a cable will preserve it from attacks of the white ant and in places where a cable is
liable to abrasion I cover it with a helical coil of steel or iron wire as I find it not
only lessens the cost of cables intended to be protected from abrasion by wire covering
in the ordinary way but it is less rigid and is laid with greater case and security.
In laying conductors for temporary purposes beneath roads with small traffic I
prefer to use one or other of the methods described in my Patent of 11th March 1867
No. 2480.
"
At any required points some of these conduits may be interrupted and "tapping
boxes inserted of sufficient length to allow of such an amount of slack to the con-
ductors being contained therein as may be required for conveniently "tapping" the
conductors, or forming branch conductors thereon leading into dwelling or other
localities that require to be supplied with the electric current especially for lighting
or telephonic purposes. These tapping boxes are closed air tight and may be filled
with Nicoll's compound No. 2.
Fig. 3 of the drawings shews a vertical section of the herein before described portable
jacketted cauldron for heating and mixing the insulating compounds either for coating
and filling the troughs in which they are laid. a is the jacketted cauldron carried in
a framing mounted on wheels and having at bottom a fire c which is by preference
a creosote lamp fed through a pipe c' the heat being intensified by blasts of com-
pressed air. d is a safety valve for the steam jacket, e is the stirrer of known
construction having two sets of loops rotated in contrary directions by gearing at f
rotated by a crank handle. The cauldron is closed at top by a removeable cover g
made in two halves.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim is
1. The use for insulating and protecting electrical conductors and their receptacles
of the herein described compound called Nicoll's compound No. 2."
6+
2. The use for preparing and heating compounds for insulating and laying
electrical conductors of jacketted mixing and heating cauldrons constructed and

page_text: operating substantially as herein described whereby the said compounds are prevented
from becoming charred.
3. Constructing continuous conduits for electrical conductors of slabs of brick
material wholly or partially with vitrified surfaces or other suitable material, fitted
together end to end and side by side, the slabs having longitudinal semicircular
grooves in their meeting sides forming together closed channels in which are
contained the coated conducting wires, substantially as herein described.
Dated this 9th day of February 1888.
ABEL & IMRAY,
Agents for the Applicant.