Improvements in the Manufacture of Cables suitable for the Distribution of Electric Currents.
Year: 1890

page_text: Date of Application, 1st Jan., 1890
Complete Specification Left. 25th Sept., 1890-Accepted, 22nd Nov.. 1890
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Cables suitable for the
Distribution of Electric Currents.
I, WILLOUGHBY STATHAM SMITH the Younger of 18 Wharf Road City Road in the
County of Middlesex, Telegraphic Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention has for its object improvements in the manufacture of cables suitable
for the distribution of electric currents.
For this purpose small strings of hemp, cotton, or other yarn are saturated by
prolonged boiling with solutions of wax resin paraffin ozokerite india rubber or the
like or with an ammoniacal solution of copper to prevent moisture from creeping along
by capillary attraction. These strings are then covered in an ordinary covering
machine with gutta percha or balata or a blending of both with which has been
worked or mixed vulcanizing agents such as are well known in the rubber trade.
Thus I sometimes employ
Gutta Percha
Balata
Whiting
Vegetable black
Sulphur
Gutta percha and balata
or
50 lbs.
50 "
60
6
6
23
"
"
100
"
Golden sulphide of antimony
10 "
For some purposes I prefer to add india rubber to the above in such quantities that
the material is not made too stiff to pass through the dies of the covering machine.
If by the addition of the india rubber the mixture becomes too stiff to pass through
the dies of the covering machine or if india rubber be used by itself the yarns may
be covered by means of an india rubber covering machine.
The
The yarns however covered are next laid closely around the metallic conductor in
numbers varying in accordance with the size of the said conductor and one two or
more layers are used until the desired thickness of insulation is arrived at.
whole is then taped or braided and finally placed in a cure and vulcanized. The time
for vulcanization being, for the mixtures given above, from 4 to 5 hours at a
temperature of about 270° Fahr.
This process ensures the metal conductor remaining quite central within the
insulating material.
The cable may be used as it is or protected from injury by means of external
metallic wires, hemp, or lead tubing.
In order that the cable may be as strong and well protected as possible I prefer to
cover the insulating material, when vulcanized, with strands of yarns which have been
saturated by immersion in carnauba wax alone or a mixture of that wax and resin, the
whole is then covered with lead tubing and warmed to the melting temperature of the
wax whilst hot it is drawn through an ordinary die plate which compresses the lead
and causes the yarns to close tightly together.
The forms of cables may be varied, for instance a metallic conductor can be
surrounded to any desired thickness by one or more layers of the covered strings and
after being served with other wires or strips of metal can be again covered with the
strings and finally vulcanized thus forming a cable consisting of two conductors. Or
metal wires can be surrounded with the cotton string or yarn and then covered with

page_text: the vulcanizing compound being afterwards twisted or laid together in any desired
numbers and vulcanized so as to form one solid mass.
Dated this 30th day of December 1889.
WILLOUGHBY STATHAM SMITH
Improvements in the Manufacture of Cables suitable for the
Distribution of Electric Currents.
I, WILLOUGHBY STATHAM SMITH the Younger, of 18 Wharf Road, City Road, in
the County of Middlesex, Telegraphic 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 :---
This invention has for its object improvements in the manufacture of cables suitable
for the distribution of electric currents.
For this purpose small strings of hemp, flax, cotton, or other yarn are saturated by
prolonged boiling with wax, resin, paraffin, ozokerite, india rubber or the like, the
saturating material being rendered liquid either by the aid of some suitable solvent
such as coal tar naptha benzine etc., or simply by the aid of heat the treatment
depending upon the substance chosen, or the yarns may be treated to prevent moisture
from creeping along by capillary attraction. I have found resin with naptha as a
solvent very suitable for use in preparing the yarns. The boiling is effected in a
closed metallic vessel exposing a considerable surface so that the solvent as it
evaporates recondenses and falls back amongst the yarns. The heat is so regulated
that only a nominal pressure is generated in the closed vessel. The boiling should be
continued for several hours These strings are then thinly covered in an ordinary
covering machine with a plastic composition consisting of gutta percha or balata or a
blending of both with which has been worked or mixed vulcanizing agents such as
are well known in the rubber trade.
Thus I sometimes employ
Gutta percha
Balata
50 lbs.
Whiting
-
Vegetable black
Sulphur
or
Gutta percha and balata
50
"
-
60
"
"
"
->>
100
"
Golden sulphide of antimony
10 "
For some purposes I prefer to add india rubber to the above in such quantities that
the material is not made too stiff to pass through the dies of the covering machine.
If by the addition of the india rubber the mixture becomes too stiff to pass through
the dies of the covering machine or if india rubber be used by itself the yarns may
be covered by means of an india rubber covering machine.
The yarns however covered are next laid closely around the metallic conductor
which is usually a strand of copper wires in number varying in accordance with the
relative dimensions of the said conductor and the covered yarns and one two or more
layers are used until the desired thickness of insulation is arrived at and where more
than one layer is employed the successive layers are laid in opposite directions.
I prefer at the moment of laying these covered yarns or threads round the
conductor to cause them to pass through a viscous solution of india rubber, gutta
percha, or balata, to which has been added vulcanizing material so that the interstices
between the threads may be more completely filled. The whole is then taped or
braided and finally placed in a cure and vulcanized. The time for vulcanization being,
for the mixtures given above, from 4 to 5 hours at a temperature of about 270° Fahr.

page_text: This process ensures the metal conductor remaining quite central within the
insulating material.
The cable may be used as it is or protected from injury by means of external
metallic wires, hemp, or lead tubing.
In order that the cable may be as strong and well protected as possible I prefer to
cover the insulating material, when vulcanized, with strands of yarns which have been
saturated by immersion in carnauba wax alone or a mixture of that wax and resin, the
whole is then covered with lead tubing and warmed to the melting temperature of the
wax-whilst hot it is drawn through an ordinary die plate which compresses the lead
and causes the yarns to close tightly together.
The forms of cables may be varied, for instance a metallic conductor can be
surrounded to any desired thickness by one or more layers of the covered strings and
after being served with other wires or strips of metal can be again covered with the
strings and finally vulcanized thus forming a cable consisting of two conductors. Or
metal wires can be surrounded with the cotton string or yarn and then covered with
the vulcanizing compound being afterwards twisted or laid together in any desired
numbers and vulcanized so as to form one solid mass.
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. In the manufacture of electric cables the use of fibrous strings covered with a
plastic vulcanisable compound, laid around a metallic conductor, then taped or braided
and afterwards vulcanised.
2. An electric cable substantially as herein described.
3. An electric cable substantially as described covered with yarns saturated with
carnauba wax with or without resin and enclosed in a tube of lead drawn down
upon it.
Dated this 22nd day of September 1890.
WILLOUGHBY S. SMITH.