IMPROVEMENTS IN CONDUCTORS OR CABLES FOR TELEPHONIC PURPOSES
Year: 1879

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for the Invention
of "IMPROVEMENTS IN CONDUCTORS OR CABLES FOR TELEPHONIC PURPOSES."
A communication from abroad by Edwin Holmes and Edwin T. Greenfield,
both of Brooklyn, New York, United States of America.
Sealed the 16th April 1880, and dated the 10th November 1879.
PROVISIONAL SPECIFICATION filed by the said William Robert Lake at
the Office of the Commissioners of Patents on the 10th November 1879.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN CONDUCTORS OR CABLES
FOR TELEPHONIC PURPOSES." [A communication from abroad by Edwin Holmes
and Edwin T. Greenfield, both of Brooklyn, New York, United States of
America.]
The object of the present Invention is to prevent or eliminate the effects of
induction in electric conductors that are arranged in near proximity to each other,
and which is one of the principal disturbing influences in the practical working of
ordinary telephonic lines.
It is well known scientifically that the intensity of the induced current depends
largely upon the parallelism between the conductor in which such current is
generated and the primary line, and that such current grows feebler as the
parallelism of the lines is destroyed, and becomes inappreciable when the lines
cross each other at right angles.
It has been proposed to utilize for a telephonic line a metallic circuit, the return
wire of which shall be made to cross and recross repeatedly the main wire of the
circuit, the expectation being that such a line will not be disturbed by induction
from a neighbouring wire through which an electric current is passing. One
practical objection to this construction is that it requires double the length of
wire as compared with a construction which uses an earth connection, and also
is attended with a vastly increased resistance; moreover, it proposes the protection
of a single line only.

page_text: The present Invention provides a more simple and less expensive mode of
utilizing the general fact above noted, and is perfectly adapted to any number
of lines arranged in proximity to each other and following the same general
direction; and it consists simply in weaving the lines in and out among themselves
so that they will repeatedly cross and recross at short intervals, each line having an
earth connection, and consequently no metallic return wire.
The most convenient manner of securing this relative arrangement of the wires
is to braid them together into a cable, for which purpose they must be properly
insulated to prevent contact of the conducting surfaces. By braiding the wires
each one of the system will cross and recross each and every one of the others, and
if the work is carefully done, as with machinery, the construction will be uniform
throughout, the nodes occurring at regular intervals, and the curves rising to
uniform heights from the axial line of the cable, which regularity of construction
will produce the most complete results. By braiding, each wire is made to act as
a support to its neighbours, and while the wires thus serve to support each other
the whole cable can be as readily mounted on poles, or otherwise supported or
submerged, as a single wire can be.
A cable constructed according to this Invention may be composed of three
insulated wires braided together; but manifestly, the same system would apply to
any larger number of wires which equally well might be braided up into a single
cable.
If two wires only were to be used they might be braided into a cable by using
as a third strand a cord of any non conducting material, or they might be secured
by sewing, or in any other available way, to a strip of tape or any other suitable
support. In this case two wires are attached to a narrow strip in such a way as to
cross and recross each other at short intervals and with regular curves.
It is found in practice that when conductors are arranged as above described no
induced current is formed in any one of them by the passage of an electric current
through any of the others, or if formed it is so far modified from what it would
otherwise be as practically not to interfere with the working of any of the lines in
the cable, and the same, measurably, would be true of them with reference to any
other line near by but not included in the same cable.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robert Lake in the Great Seal Patent Office on the
7th May 1880.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN CONDUCTORS OR CABLES
FOR TELEPHONIC PURPOSES." A communication from abroad by Edwin Holmes
and Edwin T. Greenfield, both of Brooklyn, New York, United States of
America.
The object of the present Invention is to prevent or eliminate the effect of
induction in electric conductors that are arranged in close proximity to each other,
induction being one of the principal disturbing influences in the practical working.
of ordinary telephonic lines.
It is well known scientifically that the intensity of the induced current depends
largely upon the parallelism between the conductor in which such current is
generated and the primary line, and that such current grows feebler as the
parallelism of the lines is destroyed, and becomes inappreciable when the lines
cross each other at right angles.
One
It has been proposed to utilize for a telephonic line a metallic circuit, the return
wire of which shall be made to cross and recross repeatedly the main wire of the
circuit, the expectation being that such a line will not be disturbed by induction
from a neighboring wire through which an electric current is passing.
practical objection to this construction is that it requires double the length of wire
as compared with a construction which uses an earth connection, and also is
attended with a vastly increased resistance; moreover, it affords protection to a
single line only.
The present Invention provides a more simple and less expensive mode of
utilizing the general fact above noted, and may be advantageously adapted to any
number of lines arranged in proximity to each other and following the same
general direction; and it consists simply in weaving the lines in and out among
themselves so that they will repeatedly cross and recross at short intervals, each
line having an earth-connection and consequently no metallic return conductor.
The most convenient manner of securing this relative arrangement of the wires
is to braid them together into a cable, for which purpose they must be properly
insulated to prevent contact of the conducting surfaces. By braiding the wires
each one of the system will cross and recross each and every one of the others, and
if the work is carefully done, as for instance, by machinery, the construction will be
uniform throughout, the nodes occurring at regular intervals, and the curves rising
to uniform heights from the axial line of the cable; this regularity of construction
will produce the most advantageous results. By braiding the wires each wire is
made to act as a support to its neighbors, and while the wires thus serve to support
each other the whole cable can be as readily mounted on poles, or otherwise sup-
ported or submerged, as a single wire can be.
Figure 1 of the accompanying Drawing shews a cable composed of three insulated
wires braided together, but it will be readily understood that the same system
would apply to any greater number of wires which may equally well be braided
into a single cable.
If two wires only are to be used they may be braided into a cable by using
as a third strand a cord of any non-conducting material; or they may be secured
by sewing, or in any other available way, to a strip of tape or any other suitable
support, as shewn in Figure 2. In this Figure two wires are shewn as attached
to a narrow strip in such a way as to cross and recross each other at short intervals
and with regular curves.

page_text: It is found in practice that when conductors are arranged as above described no
induced current is formed in any one of them by the passage of an electric current
through any of the others, or if formed it is so far modified as practically not to
interfere with the working of any of the lines in the cable, and the same, measur-
ably, would be true of them with reference to any other line adjacent to but not
included in the same cable.
Having thus fully described the said Invention as communicated to me by my
foreign correspondents, and the manner of performing the same, I wish it understood
that I claim,
First. The arrangement of two or more telephonic conductors with ground-
connections, and so that each conductor crosses and re-crosses each and all of the
others at short intervals, substantially as above set forth and for the purpose
specified.
Second. A cable composed of insulated telephonic conductors having ground-
connections and braided together, substantially as above set forth and for the
purpose specified.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Seventh day of May, in the year of our Lord One
thousand eight hundred and eighty.
W KOB. LAKE. (L.S.)