Improvements in Electrical Cables.
Year: 1891

page_text: Date of Application, 4th Mar., 1891
Complete Specification Left, 4th Dec., 1891-Accepted, 9th Jan., 1892
PROVISIONAL SPECIFICATION.
Improvements in Electrical Cables.
WALTER TWISS GLOVER, of Bridgewater Street, Salford, Electric Cable
Manufacturer, and GEORGE EDWARD PREECE, Springfield Lane, Salford, in the
County of Lancaster, Electrician do hereby declare the nature of this invention to
be as follows:-
Our invention relates to the construction and manufacture of those electrical
cables specially used for telephonic circuits. In those cables which are used for
single wire circuits only, various methods have been adopted for the neutralisation
of the effects of induction, due to internal and external causes, but in those cables
where a metallic circuit (or double wires) is employed, the effects of induction have
been overcome or neutralised by twisting the wires and forming pairs.
At the present time, when it is desirable to use only a single wire for each
separate circuit, but at the same time to have provision made for the future working
of circuits by metallic circuits (double wires), the employment of either one form
or other of these cabies does not enable the working of both systems to be carried
out satisfactorily, inasmuch as if a cable with single wire protected against induc-
tion be used, it is not applicable in the future to working metallic circuits, and on
the other hand if a cable be employed which is made of wires twisted in pairs, the
induction between wire and wire is too great to admit of its being worked for single
wire circuits beyond a certain limited distance.
We therefore have designed and constructed a combination form of electric
cable, which whilst admitting all or any number of the wires being worked as
single wire circuits, will permit of all or any number of wires being used as metallic
circuits. That is to say, that in a cable consisting of 100 wires, all of the 100 wires
can be used to work 100 single wire circuits without any ill effects from induction ;
or 50 metallic circuits can be used by looping the wires in pairs; or that 50 wires
can be used as single wire circuits, and the remaining 50 wires looped into 25 pairs
or metallic circuits.
:-
We construct our improved cable of-say-100 wires in the following manner :-
Around a centre or core of hemp, jute or other material which may or may not be
covered with metallic foil, are caused to be laid 4 (four) pairs of insulated
conductors, each pair being of a distinct color or shade. The insulated conductors
of one pair being protected with specially proofed black tape, the next or alternate
pair being protected with white felt or grey tape. Special reversible tape being
used for this purpose.
In this layer of 8 wires (four pairs) 'the 1st and 3rd pairs
will be of grey or white and the 2nd and 4th of black tape, thus forming pairs of
alternating and easily distinguishable color. The first wire of the first pair has
however, in this lay and in all the subsequent layers, an extra covering in the form
of metallic foil which serves a double purpose.
Over this series of 8 wires or 4 pairs are laid in succession 14 wires or 7 pairs of
insulated conductors taped alternately as before, with the first wire as stated
further distinguished by a coating of metallic foil.
Over this second series is laid in succession a third series of 20 wires or 10 pairs
of insulated conductors taped alternately as before, and over the third series a
fourth series of 26 wires or 13 pairs, and again over that a fifth series of 32 wires
or 16 pairs, thus building up a cable of 100 wires in alternate pairs of white or
grey, and black, in each of which layers the first wire of the first pair (grey) is
further distinguished by a covering of metallic foil.
Between each of the several layers, that is between the 1st and 2nd, between the
2nd and 3rd, between the 3rd and 4th, and between the 4th and 5th series a coating

page_text: of metallic foil is lapped or otherwise served in a direction opposite to the lay of the
wires. It is to be understood that each layer or series of pairs is placed in an
opposite direction to the preceding series. The cable thus formed is then covered
with one or more coatings of metallic foil, and then strongly braided & served with
preservative and weather-resisting compounds in the usual manner.
The single wire of the first pair in each layer which is coated with metallic foil,
in the first place distinguishes that particular wire as No. 1 in that layer, and
serves the purpose of carrying out a sequential method of numbering the wires
throughout the cable and in the second place it forms a good metallic connection
between the coating of metallic foil above it and that below it, so that all of the
metallic foils throughout the cable are in perfect metallic and electrical connection,
in such a way that if the cable be "carthed" at one or both ends or at any inter-
mediate points, the whole of the cable is permeated with an earth connection of
large surface and of low resistance preventing any induced currents internal or
external from disturbing the working of any single wire. With this form of cable
it will be seen that each individual wire has an earth conducting surface both above
and below it for the interception of any induced currents, whilst being worked as
single and simple telephone circuits.
The insulated conductors being made up into pairs of a distinguishing color, it is
only necessary to select any pair of the same color or type and loop them at their
ends to form a metallic circuit; as the two wires forming each pair have a twist
round each other, owing to the method of construction and are throughout their
length closely contiguous, in fact touching, and in contact, the effects of induction
are in them quite neutralised, as in a cable in which the wires are simply twisted in
the ordinary manner.
A second method of joining up the wires in pairs may be adopted which is also
of a novel character, that is, by joining up the separate wires in each layer to those
immediately opposite to them, that is to say in the first layer of eight wires to join
No. 1 to No. 5, 2 to 6, 3 to 7, and 4 to 8, and similarly with cach layer or series,
the first half of the wires to be joined to the second half seriatim and sequentially,
as for example in the third layer, join 1, 2, 3, 4, 5, 6, 7, 8, 9, 10—to 11, 12, 13, 14,
15, 16, 17, 18, 19, 20. In this manner the two wires so joined are throughout the
entire length of the cable not only exactly equidistant but are also twisting round
each other at very short intervals. Of these methods of joining up and of working
experimental proofs have been obtained of their success.
We have thus described the cable as being of 100 wires, but the same plan and
design may be carried out and is equally applicable-to cables consisting of a
greater or lesser number of wires; the essential arrangement being that each layer
or series of wires consists of an even number, divisible into pairs of a distinguishing
color or mark, one wire only being coated with metallic foil, and also that each
layer be covered by a coating of metallic foil. The wires for working a metallic
circuit to be joined up in one or other of the methods described.
Dated this 3rd day of March 1891.
WALTER TWISS GLOVER.
GEO. E. PREECE.
COMPLETE SPECIFICATION.
Improvements in Electrical Cables.
We WALTER TWISS GLOVER of Bridgwater Street Salford in the County of
Lancaster Electric Cable Manufacturer and GEORGE EDWARD PREECE of Spring-
field Lane Salford aforesaid Electrician do hereby declare the nature of our said
invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:-
Our invention relates more especially to the construction and manufacture of
electrical cables such as are used for telephone circuits.
In such cables which are

page_text: used for single wire circuits only various methods have been adapted for the
neutralization of the effects of induction due to internal and external causes but
in those cables where a metallic circuit for double wires is employed, the effects of
induction have been overcome or neutralised by twisting the wires and forming
pairs.
At the present time when it is desirable to use only a single wire for cach
separate circuit, but at the same time to have provision made for the future
working of circuits by metallic circuits (double wires) the employment of either
form or other of these cables does not enable the working on both systems to be
carried out satisfactorily, inasmuch as if a cable with single wires protected against
induction be used, it is not applicable in the future to working metallic circuits,
and on the other hand, if a cable be employed which is made of wires twisted in
pairs, the induction between wire and wire is too great to permit of its being
worked for single wire circuits beyond a certain limited distance.
We therefore have designed and constructed a combination form of electric cable,
which whilst admitting of all or any number of the wires being worked as single
wire circuits will permit of all or any number of the wires being used as metallic
circuits. That is to say, for example, that in a cable consisting of 100 wires, all the
100 wires can be used to work 100 single wire circuits without any ill effects from
induction; or 50 metallic circuits can be used by looping the wires in pairs; or
50 wires can be used as single wire circuits, and the remaining 50 wires be looped
into 25 pairs or metallic circuits.
We construct our improved cables in the following manner: We will take 100
wires as our example but we do not limit ourselves to that number: Around a
centre or core of hemp, jute or other material which may or may not be covered
with metallic foil, are laid four pairs of insulated conductors, each alternate pair
being readily distinguishable from the other pairs by a distinguishing mark as by
making them of a distinct colour or shade. The insulated conductors of one pair
are protected with specially prepared tape, the next or alternate pair being protected
with say white felt or grey tape. Special reversible tape may be used for this
purpose, that is tape colored differently on either side. In this layer of 8 wires
(four pairs) the 1st and 3rd pairs will be covered with say grey or white and
the 2nd and 4th pairs with say black tape, thus forming pairs of alternating colours
easily distinguishable from each other. The first wire of the first pair has how-
ever in this layer and in all the subsequent layers, an extra covering in the form of
metallic foil which serves a double purpose.
Over this series of 8 wires (4 pairs) are laid in succession 14 wires (7 pairs) of
insulated conductors taped alternately as before described with the first wire as
stated further distinguishable by a coating of metallic foil.
Over this second series is laid in succession a third series of 20 wires (10 pairs)
of insulated conductors taped alternately as before described and over the third
series, a fourth series of 26 wires (13 pairs) and again over that a fifth series
of 32 wires (16 pairs) thus building up a cable of 100 wires in alternate pairs of
different colours (say white or grey, and black) in each of which layers the first
wire of the first pair (grey) is further distinguished by a covering of metallic foil.
Between each of the several layers that is between the 1st and 2nd between
the 2nd and 3rd 'between the 3rd and 4th and between the 4th and 5th series a
coating of metallic foil is lapped or otherwise served in a direction opposite to the
lay of the wires. It is to be understood that each layer or series of pairs is placed
in a direction opposite to that in which the preceding layer or series is placed.
The cable thus formed is then covered with one or more coatings of metallic foil,
and then strongly braided and served with preservative and weather resisting com-
pound which may be done in the usual manner.
The single wire of the first pair in each layer which is coated with metallic foil,
in the first place distinguishes that particular wire as No. 1 in that layer, and
serves the purpose of carrying out a sequential method of numbering the wires
throughout the cable; and in the second place it forms a good metallic connection

page_text: between the coating of metallic foil above it and that below it, so that all of the
metallic foils throughout the cable are in perfect metallic and electrical connection,
in such a way that if the cable be "earthed" at one or both ends or at any inter-
mediate points the whole of the cable is permeated with an earth connection of
large surface and of low resistance preventing any induced currents internal or
external from disturbing the working of any single wire. With this form of cable
it will be seen that each individual wire has an earth conducting surface both
above and below it, for the interception of any induced currents whilst being
worked as single and simple telephone circuits.
The insulated conductors being made up into pairs of a distinguishing colour, it
is only necessary to select any pair (two wires) of the same colour or type and
connect them at their ends to form a metallic circuit as the two wires forming each
pair have a twist round each other owing to the method of construction and are
throughout their length contiguous or close together, the effects of induction are in
them quite neutralised as in a cable in which the wires are simply twisted in the
ordinary manner.
.
A second method of joining up the wires in pairs may be adopted which is also
of a novel character, that is by joining up the separate wires in each layer to those
immediately opposite to them, that is to say, in the first layer of eight wires to
join No. 1 to No. 5, No. 2 to No. 6, No. 3 to No. 7 and No. 4 to No. 8 and
similarly with each layer or series, the first half of the wires to be joined to the
second half seriatim and sequentially, as for example in the third layer: join 1, 2,
3, 4, 5, 6, 7, 8, 9, 10 to 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 respectively.
In this manner the two wires so joined are throughout the entire length of the
cable not only exactly equidistant but are also twisting round each other at very
short intervals.
We have thus described the cable as being of 100 wires, but the same plan and
design it will be evident is applicable to cables consisting of a greater or lesser
number of wires, the essential arrangement being that each layer or series of wires
consists of an even number readily divisible into pairs by a distinguishable colour
or mark, one wire only being coated with metallic foil, and also that each layer be
covered by a coating of metallic foil, so that the wires for working a metallic
circuit can be readily selected and joined up as hereinbefore described.
Although we have hereinbefore described a cable with a core of hemp or other
material, yet we may otherwise arrange it, for example in say a 52 wire cable, the
core or centre is conveniently formed of an even number of conductors say for
instance of four wires (two pairs) of insulated conductors, one pair being distin-
guished by grey tape and the other by black tape around this centre we lap a
layer of lead-foil, and over this we place a layer of insulated conductors consisting
of 10 wires (5 pairs) of alternate grey and black taped conductors, but the first
conductor of the first grey pair has an external lapping of lead-foil, over this layer
is a lapping of lead-foil, and on this we place a layer of insulated conductors con-
sisting of 16 wires (8 pairs) arranged similarly to the preceding layer with
alternate pairs of grey and black taped conductors, in this layer again the first
grey covered conductor is lapped with lead-foil around this layer of conductors
is placed a lapping of lead-foil, and finally over this we place a concluding layer
of 22 conductors arranged in 11 pairs of alternate grey and black.taped conductors,
with the first conductor of the first grey pair lapped with lead-foil, thus bringing
the total numbers of conductors to 52 (26 pairs). The cable so built up may be
lapped with two coatings of lead-foil and braided with two braids and served with
compounds as in the 100 wire cable already described. The lead foil in each layer
serves to designate the number of the wire and also to electrically connect the
several lead-foil lappings into one conducting medium permeating the cable.
Figure 1 of the accompanying drawing shews a section of a 52 wire cable in
which the two colours of the taped conductors (say grey and black) are shewn
respectively by the white or plain, and the shaded or cross hatched circles. In the
centre are the 4 conductors a arranged as two white and two shaded. Over this is

page_text: foil
the lapping of lead-foil, 6 the second layer is shewn consisting of a
conductor c with a circle round it to shew the lead-foil c² next to it, to the right or
"white"
in the direction of the arrow, is another "white" which form the first pair,
"shaded" and "white" conductors follow in pairs to a total of 10 conductors.
Over the second layer is the lapping of lead foil and around this the third layer
of 16 conductors, the first of which, the "white" conductor d has a circle of lead
round it, the wires to the right are arranged as before in pairs of. "shaded
white conductors. Round this third layer is shewn a lapping of lead
foil and over the lead foil the fourth or final layer consisting of 22 conductors,
of which the first "white" conductor e is marked with a circle e to designate the
lead-foil. The succeeding wires are arranged as in the other layers in alternate
pairs of shaded" and "white" conductors. Layers of lead foil (say two) are
lapped over the cable built up as described. The lead foil covered conductors c d e
will be seen to metallically connect the several layers of lead-foil
and
32
together.
By leaving out one pair of conductors in the centre and substituting dummy strands
the 52 wire cable would become a 50 wire cable.
Various other combinations as regards the number of conductors can be formed,
but due attention must be had to the necessity of arranging the several layers in
even numbers, so that pairs are formed of alternately different colours or markings
and that the first wire in each layer be covered with lead-foil in order to metallically
connect the intervening layers of lead foil as well as to facilitate the numbering.
Figure 2 shews a perspective view of a 52 wire cable in which the relative
positions of the layers of lead foil and of insulated conductors may be seen, as well
as the arrangement of the pairs of different colours or shades. At f the braiding
over the completed cable is shewn.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the said electric cables are manufactured and worked
for the purpose of telephonic circuits we declare that what we claim is,--
An electrical cable in which the conductors are arranged and distinguished in
pairs substantially as hereinbefore described and for the purpose of working either
single or metallic circuits separately or jointly substantially as hereinbefore
explained.
Dated this 4th day of December 1891