IMPROVE- MENTS IN OR CONNECTED WITH ELECTRIC CABLES
Year: 1882

page_text: LETTERS PATENT to Thomas John Handford, of 42, Southampton Buildings,
in the County of Middlesex, Patent Agent, for an Invention of " IMPROVE-
MENTS IN OR CONNECTED WITH ELECTRIC CABLES." A communication from
abroad by Patrick Bernard Delany, of the City County and State of New
York United States of America.
PROVISIONAL SPECIFICATION left by the said Thomas John Handford at
the Office of the Commissioners of Patents on the 23rd January 1882.
THOMAS JOHN HANDFORD of 42 'Southampton Buildings in the County of
Middlesex Patent Agent. "IMPROVEMENTS IN OR CONNECTED WITH ELECTRIC
CABLES." A communication from abroad by Patrick Bernard Delany of the
City County and State of New York United States of America.
This Invention relates to that class of Electric Cables in which provision is
made for obviating the effects of induction by the wires upon each other.
A Cable has heretofore been composed of a number of insulated wires braided or
plaited together so that they will cross and recross each other at short intervals
thus destroying the parallelism upon which depends in a great measure the
induction of conductors upon each other but even in a cable so constructed there
are short spaces at short intervals where some of the wires approximate to
parallelism and therefore inductive impulses will be felt by the wires.
These impulses although slight seperately will in a cable of moderate length
produce an aggregate effect more or less retarding to the direct currents over the
wires. For instance if upon one of the wires is used a strong battery current and
upon another a weak magneto current such as are ordinarily used upon Telephone
wires the strong current will by induction very materially interfere with the
weaker.
It is well understood that when a third conductor is interposed between two
other parallel or approximately parallel conductors upon which currents are
flowing the intermediate conductor will intercept the induction of the outside
Conductors towards each other so that their currents will be unaffected thereby.
--
.

page_text: It is the object of this Invention to interpose a continuous conductor into the
meshes between the wires of a plaited or braided Cable and thus eliminate from
this class of Cables the last vestige of induction.
The Invention consists in an electric cable composed of a number of braided or
plaited insulated wires enclosed in a metallic tube and having a conducting
substance in the meshes between the wires and in contact with the tube whereby
an intermediate Conductor is secured between any two wires of the Cable at all
points where they are parallel or nearly so this intermediate Conductor intercepting
the intermittant inductive impulses which the wires would otherwise exert upon
each other.
In practice I prefer to weave the insulated wires loosely into a flat braid or plait
so that they will cross and recross each other at short intervals but have open
meshes between them. This plait I introduce into a flat pipe of lead or other
ductile or pliable metal and then pass the tube Hatwise between compression
rollers producing upon it a strong compression which will force the inner surfaces
of the tube together through the meshes between the wires.
I do not confine myself however to this method of forming the Cable as the
braid or plait of wires may have the tube or pipe cast around it and into its
meshes as for instance by passing the braid or plait thro' a hollow mandril and
properly shaped mould or die of a lead pipe Machine..

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas John Handford in the Great Seal Patent Office on the
21st July 1882.
THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex, Patent Agent. "IMPROVEMENTS IN OR CONNECTED WITH ELECTRIC
CABLES." A communication from abroad by Patrick Bernard Delany of the City,
County, and State of New York, United States of America.
The said Invention relates to that class of electric cables in which provision is
made for obviating the effects of induction by the wires upon each other.
A cable has previously been constructed composed of a number of insulated
wires braided or plaited together so that they will cross and recross each other at
short intervals, thus destroying the parallelism upon which depends in a great
measure the induction of conductors upon each other, but even in a cablo so con-
structed there are short spaces at short intervals where some of the wires
approximate to parallelism, and therefore inductive impulses will be felt by the
wires.
These impulses although slight separately will in a cable of moderate length
produce an aggregate effect more or less retarding to the direct currents over the
wires. For instance if upon one of the wires is used a strong battery current and
upon another a weak magneto current such as are ordinarily used upon Telephone
wires, the strong current will by induction very materially interfere with the
weaker.
It is well understood that when a third conductor is interposed between two
other parallel or approximately parallel conductors upon which currents are
flowing the intermediate conductor will intercept the induction of the outside
conductors towards each other so that their currents will be unaffected thereby.
It is the object of this Invention to interpose a continuous conductor into the
meshes between the wires of a plaited or braided cable, and thus eliminate from
this class of cables the last vestige of induction.
The invention consists of an electric cable composed of a number of braided or
plaited insulated wires enclosed in a metallic tubo and having a conducting sub-
stance in the meshes between the wires and in contact with the tube whereby an
intermediate conductor is secured between any two wires of the cable at all points
where they are parallel or nearly so, this intermediate conductor intercepting the
intermittant inductive impulses which the wires would otherwise exert upon each
other.
In practice it is preferred to weave the insulated wires loosely into a flat braid
or plait, so that they will cross and recross each other at short intervals but have
open meshes between them. This plait is introduced into a flat pipe of lead or
other ductile or pliable metal and the tube is then passed flatwise between com-
pression rollers, producing upon it a strong compression which will force the inner
surfaces of the tube together through the meshes between the wires.
I do not confine myself however to this method of forming the cable as the braid
or plait of wires may have the tube or pipe cast around it and into its meshes, as
for instance by passing the braid or plait through a hollow mandril and properly
shaped mould or die of a lead pipe machine.
In the accompanying drawing Figure 1 is a view partly in section of a cable
constructed according to the said Invention. Figures 2, and 3, are cross sections
of the same taken along the lines x, x and y, y respectively in Figure 1. Figure 4,
is a view of the plait or braid of insulated wires before it is introduced into the
tube. The insulated wires are indicated by the letter a. It will be observed that

page_text: they cross and recross each other at short intervals, but at certain points as shown
at a some of the wires will be nearly parallel with each other and it is at these
points that they would exert inductive impulses upon each other, were not a con-
ductor interposed between them as before explained. The letter b indicates the
enclosing pipe the sides of which are so compressed together that their inner
surfaces protrude and meet between the wires. Or the pipe may be so cast on the
braid as before explained that the metallic portions in the meshes will connect the
sides of the pipe integrally.
Having now described and particularly ascertained the nature of the said
Invention and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that I do not claim broadly as of the present
Invention a flat electric cable composed of insulated wires laid side by side and
enclosed by a metal covering compressed upon the wires and filling the interstices
between them, nor constructing such a cable in sections, the wires in which are
parallel throughout each section, but at the joints of the sections are crossed and
take different positions relatively to each other, as such arrangements are described
in the specification to Letters Patent granted to George Edward Gouraud dated
the 10th day of June 1881. No. 2532 but what I consider to be novel and original
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is
In an electric cable the combination with a number of insulated wires in a flat
braid or plait, and crossing and recrossing each other at short intervals, of a flat
flexible metallic tube enclosing the said braid or plait and having its opposite inner
surfaces metallically connected through the meshes of the said braid or plait
substantially as herein before described.
-In-witness whereof I the said Thomas John Handford have hereunto set my
hand and seal this Thirteenth day of June in the year of our Lord One
thousand eight hundred and eighty two.