Year: 1886

page_text: I, WALTER TWISS GLOVER of Bridgewater Street Salford in the County of
Lancaster, Covered Wire Manufacturer do hereby declare the nature of this
invention to be as follows:-
This Invention relates to electric cables and more particularly to cables con-
taining conductors of electro-telephonic circuits and these Improvements have for
their objects the construction of cables in which each of the conductors may be
shielded or protected from the influence or effect of electric currents in any of the
wires or conductors within the cable or in neighbouring conductors and from other
internal or external disturbing influences and further, they have for their object
to dispense where or when desirable with the use of suspending wires in the
erection of the cables.
These Improvements consist in the construction or manufacture of cables having
a central metallic core around which the insulated conductors are laid, these in
their turn being successively overlaid with a metallic coating, insulating material
and protective sheathings or coatings. In some cases a second metallic overlay
may be interposed between the insulating material and the external sheathing or
coating.
The central metallic core may consist of a single wire or of stranded wires of a
sufficient strength to support the cable when erected without the use of suspending
wires and this core may be earthed at each end of the cable or at any convenient
intermediate point or points.
Around the core which may or may not be previously insulated the conducting
wires are laid in the usual or any convenient manner and are then overlaid with a
thin metallic foil or sheathing. Indiarubber gutta percha or other suitable insu-
lating material is next laid or applied upon the metallic foil or sheathing and
over the insulating material there may or may not be laid a second metallic
coating or sheathing.
When a second metallic coating is used the conductors are more effectually
protected or shielded from induction and other electrical influences or disturbances
and the indiarubber gutta-percha or other insulating material is also protected or
shielded from external heat. Upon the insulating material or upon the second
metallic coating as the case may be, there is laid braided or otherwise applied one
or more layers of yarn or other suitable covering.

page_text: Provision may if desired be made during or after the construction or manu-
facture of the cable to enable the metallic coating or coatings to be electrically
connected to earth either in conjunction with or independently of the core and it
or they should be connected to earth at each end of the cable or at some other
convenient point or points.
Cables manufactured or constructed as hereinbefore described may be erected
singly or two or more of them may be laid together before or during erection
alone or in conjunction with one or more single or stranded wires and they may be
suspended by wires or not as may be desirable or convenient.
An advantage of the grouping of the cables is that one or more wires or con-
ductors may be led out without disturbing the insulation of the whole group, or
one of the cables may be led off at any desired point without disturbing the
condition of the others.
I do not bind myself to the herein before described sequence order or arrange-
ment of servings in or upon the cable as these may be considerably varied.
Dated this 10th dow of Fahm
A T. 1906

page_text: improvements in and relating to Electric Cables.
I, WALTER TWISS GLOVEB, of Bridgewater Street, Salford in the County of
Lancaster, Covered Wire Manufacturer, 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 relates to electric cables, and more particularly to cables con-
taining conductors for electro-telephonic circuits, and these Improvements have for
their objects the construction and formation of cables in which each or all of the
conductors contained therein may be shielded or protected from the disturbing
influence or effect of electric currents in other conductors within the same or
contiguous cables or in neighboring wires or conductors as well as from other
disturbing influences; and further, they have for their object to dispense when
and where desirable with the use of suspending wires in the erection of cables for
telephonic and telegraphic purposes.
c
These Improvements consist in the construction and manufacture of cables with
a central metallic core around which the insulated conductors are laid. The
insulated conductors are overlaid with a metallic coating, insulating material and
protective sheathings or coatings. If more than one series or surrounding of
insulating conductors are employed, each following series or surrounding may or
may not be preceded and succeeded by a metallic coating or coatings. In some
cases a second metallic coating or overlay may be interposed between the insulating
material and the external sheathing or coating.
The character and dimensions of the metallic core must in each case be deter-
mined by the character dimensions and destination of the cable. For an ordinary
aerial cable the core may consist of a single wire of galvanized iron or steel or of
similar wires stranded, of a sufficient strength to support the cable when erected
without the use of external suspending wires. For cables which are not required
to be self-suspending a similar core to that herein before described for aerial cables
may be employed, as for example, in cables to be employed underground or under
water but in such cases I generally prefer to employ a lighter core of copper.or
other metal of good conductivity. In either case the core may be insulated, but
to enable the metallic coating or coatings to be electrically connected to earth in
conjunction with the core, it is desirable not to insulate the core, in which case
continuous metallic contact will be made between the core and the metallic
sheathings by means of the metallic coating of the hereinafter described foiled
conductors or foiled minor cables, the core itself being earthed.
Around the insulated or uninsulated core the insulated conducting wires are laid
in the usual or in any convenient manner. In ordinary cases I prefer to proceed in
the following manner :-The conducting wires are first insulated and by preference
with one or more lappings or coatings of india rubber or alternatively, with hemp
jute cotton or other fibrous yarn soaked or prepared with any of the well known
insulating materials or compounds, or with vulcanized india rubber gutta perch or
other suitable insulating material or compound. The insulated conductors are then
laid around the core and built up to the required number, and; are surrounded by.

page_text: an envelope or serving of india rubber or other suitable insulating material which
is further surrounded by a metallic sheathing and the cable may finally be finished
by braiding or be otherwise protected.
Some of the wires to be used as conductors may be lapped wrapped or served
with tin lead or other suitable metallic coating after being insulated as hereinbefore
described; these wires are herein called the foiled conductors to distinguish them
from the ordinary insulated conductors. Six or more insulated conductors of which
one or more may be foiled conductors, are laid or wound helically or spirally
around the core and there is then laid upon the cable consisting of the six or more
conductors and the core, a coating of tin lead or other suitable metal which may
be served lapped or wound thereon in such a manner that the whole surface of the
cable is covered with a metallic envelope.
When it is required to include more conductors in the cable than are contained
in the series or surrounding next to the core, a second series or surrounding
of insulated conductors may be laid or wound around the metallic coating and
over the second series or surrounding of insulated conductors there is laid or
applied a second metallic coating similar to the first. Beyond this, as many series
or surroundings of conductors and of metallic coatings may be successively laid or
applied in similar manner as may be required. In each of the series or surrounding
of insulated conductors there may be one or more foiled insulated conductors.
Instead of the insulated conductors being laid in surroundings or series of six
or more helically around the core or around the partly constructed cable as
hereinbefore described, the insulated conductors may be laid up separately in small
cables each of which may consist of or include three five seven or other convenient
number of insulated conductors and six or other convenient number of these small
cables may be wound around the core or around the partly formed cable. When
the small or minor cables are employed each of them may have a central wire or
core as herein before described for the larger cables and one or more for the minor
cables in each layer or series may be metal coated also as herein before described.
It will be understood that the method of constructing a cable with a layer or with
layers or surroundings of grouped cables is substantially the same as hereinbefore
described the chief difference being that small cables are substituted for single
insulated conductors. This multiple or compound form of cable may include fifty
one hundred or other considerable number of insulated conductors in a very
compact form while the method of construction enables the disturbing effects of
currents in neighbouring conductors to be carried off prevented or neutralized.
After the desired number of insulated conductors and layer or layers of metallic
covering have been laid the cable is sheathed armoured or protected in any usual
or convenient manner. For example, the layer or final layer of metallic covering
may have laid upon it or the cable may be served with a waterproof covering of
india rubber or of other insulating or waterproofing material, this may be protected
by lappings or braidings of cotton hemp or other yarn or thread prepared with
water resisting compounds. Instead of or in conjunction with the waterproof
materials or compounds the following method of externally protecting the cable
may be adopted, especially when the cable is to be used under ground with or
without a conduit. One or more coverings of lead to which a small quantity
of tin may be added is or are drawn over the cable in such a manner that the lead
covering or envelope forms a watertight pipe or tube. This lead covering preventa
the entry of moisture of any kind into the cable, maintains the conductors in a
good state of insulation and tends also to lessen induction therein and other effects.
of external electrical influences. Alternatively, strips of brass or copper ribbon or
tape may be wound evenly around the cable when it has to be placed underground
or it may be armoured with galvanized iron wires when required to be placed in
water.
The hereinbefore described method of construction greatly aids in the localization
or identification of any particular wire or conductor, since the foiling of some of
the conductors or minor cables identifies them at either and or at any part of the

page_text: cable and the position of any other conductors or minor cables in relation thereto
must be the same at every part of the cable.
One of the objects of this Invention, that is to say shielding or protecting the
insulated conductors from induction or the influence of external electrical currents
and similar disturbing agencies is attained by means of the core in combination
with the metallic sheathing or sheathings (which may or may not be electrically
connected by means of the foiled insulated conductors) both or all of which must
be adequately earthed in use. This earthing may be effected in the following
or similar manner:-The core and metallic sheathing or sheathings are earthed
at each end of the cable; the final metallic sheathing may also be earthed at
intermediate points as for example at the points of suspension.
In order still further to diminish and neutralize inductive and other electrical
disturbances in the insulated conductors when foiled conductors are not used one
or more covered or uncovered copper or other metallic conductors may be laid up
with the insulated conductors and be electrically connected to earth at each end.
Cables constructed as hereinbefore described may be erected singly or two or
more of them may be laid together before or during erection alone or in combination
with one or more single or stranded wires.
An advantage of this method of erection is that one or more wires or conductors
may be led out of the grouped cables without disturbing the insulation of the.
whole group or one of the cables may be led off at any desired point without
affecting the condition of the others.
I do not bind myself to the hereinbefore described order sequence or arrangement
of servings in or upon the cable as these may be considerably modified without
departing from this Invention.
A metallic core has already been used in cables of telegraphic and telephonic
conductors for anti-induction purposes; I desire it to be understood therefore that
I do not make any claim for the use of a metallic core except as hereinafter set
forth.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is:-
(1) In an electric cable containing insulated telephonic or telegraphic conductors;
the combination of a metallic core with one or more metallic sheathings the core
and the sheathing or sheathings being connected to earth when the cable is in use;
for the purpose of diminishing, or neutralizing the effects of induction, substantially
as hereinbefore described.
(2) An electric cable for telegraphic and telephonic purposes; consisting essentially
of a metallic core, one or more series or surroundings of insulated conductors, a
metallic layer sheathing or coating upon or around each series or surroundings of
insulated conductors, and means for electrically connecting the core and the metallic
sheathing or sheathings with each other and to earth; substantially as and for the
purposes herein before described.