IMPROVEMENTS IN AND RELATING TO INSULATED WIRES AND CABLES AND IN THE METHODS OF INSULATING, FIXING, AND LAYING THE SAME FOR TELEGRAPHIC AND OTHER PURPOSES
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by Walker Moseley at the Office of the
Commissioners of Patents on the 23rd July 1879.
WALKER MOSELEY, of Liverpool, in the County of Lancaster. "IMPROVEMENTS
IN AND RELATING TO INSULATED WIRES AND CABLES AND IN THE METHODS OF
INSULATING, FIXING, AND LAYING THE SAME FOR TELEGRAPHIC AND OTHER
PURPOSES."
The object of this Invention is to obtain more perfect and permanent insulation
in electro conductors, to facilitate their being fixed or laid in position, and in many
cases to reduce their expense. Up to the present time it is found that insulated
wires fixed on land, whether the insulator be gutta percha, india rubber, or any
nonconducting compound, become so much deteriorated by various atmospheric
changes and pollution that the defects in the nonconducting substance expose the
wire to the effects of dampness, in which case the electric current, whenever it
meets with a "return" (whether by "earth or otherwise) acts through the water
to the dissolution of the wire until complete rupture takes place.
"
In the case of submarine cables it is found that gutta percha loses its virtue as
an insulator and contracts during the process, whilst india rubber does so by
increasing in bulk through its absorption of water; submarine insects are also found
to attack and penetrate the gutta percha. The various compounds that have been
tried have also failed to retain their insulating properties. The materials hitherto
adopted to insulate the conducting wires offering very little resistance to pressure
or tension have required great support and protection which has been generally
effected by surrounding the core with tape, fibre, iron and steel wire, etcetrea. This
has led to the adoption of cables of bulky construction without effecting sufficient
protection; it is found that comparatively light cables are quite as effective and
durable as the heavier ones.
My experience of all the pliable nonconductors is that they will not resist the
action of air and water, but since adopting the method described in my Patent No.
2926, 1873, for the protection of the positive wire in electric plant, I have found
that the insulation remains quite perfect in ships fitted five years ago. I have
now devised means for obtaining the same object in relation to "line" wires. I
am aware that the protection of insulated wires by metal or other tubes, etcetera, is
old, but my Invention is designed to overcome all the difficulties and objections
that have attended every attempt to adopt them. In my Invention I abandon the

page_text: idea that the insulating material must necessarily be waterproof. Any fibre that
has good strength and good insulating properties will answer the purpose, but I
prefer horse hair as having the best combination of desirable properties, viz., a
perfect insulator, great tensile strength, very unyielding to any blow or pressure,
very pliable and strong elasticity. I propose to surround the wire or cable with
twisted strands of this material, then to saturate the whole with melted resin or
gum with a little oil to toughen it. I then enclose it in a double sheathing of
copper or other metal with tin or composition between the double sheath, but the
melting point of the soldering metal must not be so great as to injure the hair.
The method I propose to adopt which is one part of my Invention is as follows:-
The size of copper conductor being given and the thickness of the insulation being
determined,
procure sufficient lengths of copper tape of such width as will
envelope the circumference. I then tie both sides by passing the whole through
molten tin in a bath provided with a wiper at each end, the one at its entrance
being supplied with powdered resin, and the one at the exit to wipe off all surplus
metal adhering. I provide also equal lengths of tin tape, or a softer metal alloy if
desired, and another series of copper tape of three thicknesses wider than the other
copper tape. I then proceed to pass the insulated wire along with the first tape
through hollow edged rollers thus folding the tape longitudinally round the covered
wire. I then apply the tin tape in the same way with the joint reversed to the
opposite side. I then apply the second copper tape in the same way and at the
same time I follow this operation by causing the triple tape covered wire to pass
through a block of iron with the hole wider at the entrance than at the exit; a
thermometer being inserted in a hole made for the purpose, the block of iron will
be kept heated to about 450°; as the covered wire is drawn through this block the
two copper tapes will be soldered together forming a solid metal sheath of equal
thickness all round.
If the average supply of horse hair be found to suffer any injury when subjected
to a heat of 450° it will be desirable to alloy the tin with bismuth, but my
experiments indicate that pure tin in a molten state deteriorates neither the
elasticity nor tensile strength of horse hair.
For submarine cables I may corrugate the metal sheathing with annular
corrugations for the purpose of making it more pliable, but I do not consider this
necessary. I may also cover the metal sheathed cable with strands of fibre and
wire, but I doubt its desirability except for the shore ends.
By this method as briefly described I obtain perfect insulation and strength for
telephone conductors and like purposes, by using about one pound weight of hair to
thirty yards of wire, and for submarine cables about one pound of hair to three
yards of wire. I may also employ other fibre in combination with the hair.
In order to relieve these light cables more effectually from any sudden strain
from the ship rising suddenly in rough water (a difficulty which I believe does not
arise with the ordinary cables) I propose to cradle a pulley at the end of a long arm,
say twenty feet long, the said arm to be counterbalanced so that an extra strain of
say two hundred weight is needed to pull it over. The cable being made to pass
over this pulley at the end of the arm, which in its normal position shall be upright
and thence over a pulley at the ship's bows, it will follow that a sudden rise of the
ship will overtake the speed of the paying out machinery, and the long arm will
be pulled over; the paying out machine may then be accelerated either by the
automatic action of a spur at the bottom of the long arm gearing into the machine
or else by a man constantly standing by.