IMPROVEMENTS IN MANUFACTURE OF INSULATED ELECTRIC CONDUCTORS
Year: 1868

page_text: LETTERS PATENT to Matthew Gray, of Highbury, in the County of
Middlesex, Engineer, for the Invention of "IMPROVEMENTS IN
MANUFACTURE OF INSULATED ELECTRIC CONDUCTORS."
Sealed the 9th October 1868, and dated the 27th May 1868.
PROVISIONAL SPECIFICATION left by the said Matthew Gray at the
Office of the Commissioners of Patents, with his Petition, on the
27th May 1868.
I, MATTHEW GRAY, of Highbury, in the County of Middlesex,
Engineer, do hereby declare the nature of the said Invention for "IM-
PROVEMENTS IN THE MANUFACTURE OF INSULATED ELECTRIC CONDUCTORS," to be
as follows:-
My Invention relates more particularly to submarine or subterranean
electric conductors which are covered with some insulating composition,
such as vulcanized india-rubber or its compounds.
The object of the Invention is to facilitate the junction of lengths of
cable, which operation as at present performed is somewhat difficult,
owing to the non-adhesive property of vulcanized rubber which forms
the insulating covering of the wire or electric conductor. It is well

page_text: known that although vulcanized rubber cannot be easily joined the
prepared rubber before the curing operation has been performed thereon
unites with the greatest facility and forms a perfect joint.
The present Invention consists in curing or vulcanizing the applied
insulating compound in such a manner that while the main body of the
insulating substance throughout the length of the cable is cured or
vulcanized in the ordinary manner, a short piece, say from one to two
feet, of the end of the conductor is left uncured and unchanged, so that
the next length can be joined on without difficulty. To this end the
vessel in which the curing or vulcanizing process is carried on is
provided with openings, through which the ends of the conductor may
be allowed to project, so that those portions may not be operated on by
the curing process. By this means the entire length of the insulating
covering of the electric conductor (with the exception of a few inches
at the ends) will be cured or vulcanized, while the ends will remain
unchanged. The vulcanizing process having been thus far completed
the cable is to be removed from the vulcanizing vessel and the uncured
end joined on to the end of another length, which may then be cured in
the same manner.
When it is required to join two ends that are covered with vulcanized
rubber, as will be the case when a fault has to be cut out of the cable,
I first cut away the insulating compound for a few inches from the
extremity of each of the ends that require to be joined; the wires are
then to be soldered and covered with uncured rubber compound in the
usual manner. This uncured part of the insulating compound is then
to be placed in a small vulcanizing vessel, through the sides of which
the cable will project, and hot steam being admitted to the interior
of the vessel the change called vulcanization will then be effected.
It will be understood from the above description that the object I
have in view is to remove the ends of the cable from the influence of
the vulcanizing process, and this I do by causing the end to project
out of the vulcanizing vessel, but as the change in the rubber can only
be effected by the influence of heat. it will be evident that, if by any
means I can cover up the end and protect it from the heat to which
the other part of the cable is to be subjected I shall effect the object I
have in view. This may be done by placing the end (that is to be left
uncured) in a box or vessel surrounded by some bad conductor of heat,
such as sand, charcoal, or asbestos; or the end of the cable may be

page_text: surrounded by water, which if allowed to flow slowly through the pro-
tecting box or vessel will carry off the heat from the cable and prevent
that part (which is protected) from undergoing the change of vulcani-
zation.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Matthew Gray in the Great Seal Patent Office on
the 27th November 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MATTHEW
GRAY, of Highbury, in the County of Middlesex, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-seventh day of May, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Matthew Gray, Her special licence that
I, the said Matthew Gray, my executors, administrators, and assigns,
or such others as I, the said Matthew Gray, my executors, adminis-
trators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE MANU-
FACTURE OF INSULATED ELECTRIC CONDUCTORS," upon the condition (amongst
others) that I, the said Matthew Gray, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Matthew Gray, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Drawing hereunto
annexed, and to the letters and figures marked thereon (that is to
say):

page_text: My Invention relates more particularly to submarine or subterranean
electric conductors which are covered with some insulating composition,
such as vulcanized india-rubber or its compounds.
The object of the Invention is to facilitate the junction of the
lengths of coated wire which go to form a cable. This operation as at
present performed is somewhat difficult, owing to the non-adhesive
property of vulcanized rubber which forms the insulating covering of
the wire or electric conductor. It is well known that although
vulcanized rubber cannot be easily joined the prepared rubber before
the curing or vulcanizing operation has been performed thereon unites
with the greatest facility and forms a perfect joint.
The present Invention consists, firstly, in curing or vulcanizing the
successive lengths of the cable as they are joined up in such a manner
that the free end for, say, from one to two feet of its length will be left
uncured and unchanged, so that the next length can be joined on
without difficulty.
The Invention consists, secondly, in a mode of facilitating the
joining up cured lengths of insulated electric conductors.
In carrying out the first head of the Invention I form in the curing
or vulcanizing vessel two openings, through which the ends of the
conductor when coiled up in the curing vessel are allowed to project, so
that those portions may not be operated on by the curing process.
In the accompanying Drawing, Fig. 1 shews in longitudinal section
and Fig. 2 in front view the curing or vulcanizing vessel charged with a
length of cable laid in three coils. The coils I form by laying the
covered wire in its green state by hand around a conical core, which when
a given length has been laid around it is withdrawn. The coils thus
formed are run into the vessel on a carriage. The vulcanizing vessel is
made somewhat like a steam boiler of any desired size to suit the require-
ments of the manufacturer, and with an open flanged end, which is
closed steam-tight by a hinged flanged door. Across the flanges of the
door and the vessel corresponding half round grooves are formed to
receive the ends thereof and allow the extremities to be exposed to
the atmosphere. When additions are made to the cable the portions
of the coated wire or cable enclosed between the flanges will form the
free end of the coiled cable contained in the vessel, and the connection
of that part of the cable with the cured portion outside the vessel..
When the length of cable is secured in the curing vessel as explained

page_text: and the vessel is closed air-tight steam is admitted thereto, and the
supply kept up until the curing of that portion of the cable submitted
to the action of the steam is effected. On removing the cable from the
curing vessel it will be found that the coated cable has been cured or
vulcanized, while the end or ends protected by exposure in the air from
the heat of the curing vessel remained unchanged. The vulcanizing
process having been thus far completed the uncured end is joined on to
the end of another length, which is then to be cured in the same
manner.
As a modification of the above I propose to place that end of the
cable which it is desired to protect from the action of the steam
heat in a tubular vessel contained in the vulcanizing vessel, as shewn
in the Diagram, Fig. 3, and imbed it in a bad conductor of heat. The
better to protect it I form around the tube a water jacket, through
which I cause a stream of water to circulate, and I then effectually
secure a low temperature around the end of the cable.
covered with
When it is required to join two ends that are
vulcanized rubber, as will be the case when a fault has to be cut out of
the cable, I first cut away the insulating compound for a few inches
from the extremity of each of the ends that require to be joined, and
having coupled the wires by soldering I cover the joint with uncured
rubber compound in the usual manner. This uncured part of the
insulating compound I then place in a small vulcanizing vessel, similar
to that shewn in longitudinal section at Fig. 4, in plan view at Fig. 5,
and in end view at Fig. 6. This vessel consists of a cast-iron box and
cover with broad end flanges which are formed with corresponding half
round grooves to receive the joined cables. These grooves are so
proportioned, both as respects their length and diameter, as to allow of
the cable fitting therein steam-tight. Hot steam being admitted to the
interior of the vessel and maintained a suitable time, the change called
vulcanization will then be effected.
Having now set forth the nature of my Invention of "Improvements
in the Manufacture of Insulated Electric Conductors, and explained the
manner of carrying the same into effect, I wish it to be understood that
under the herein-before in part recited Letters Patent, I claim,—
First. The means described for curing insulated electric conductors
composed of lengths of united coated wire.

page_text: Secondly. The means described for uniting lengths of covered wire
that have undergone the curing process.
In witness whereof, I, the said Matthew Gray, have hereunto
set my hand and seal, the Twenty-seventh day of November, in
the year of our Lord One thousand eight hundred and sixty-
eight.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
MATTHEW GRAY. (L.S.)