IMPROVEMENTS IN TELEGRAPH OR TELEPHONE CONDUCTORS
Year: 1881

page_text: LETTERS PATENT to John Imray, of No. 28, Southampton Buildings, in the
County of Middlesex, for an Invention of "IMPROVEMENTS IN TELEGRAPH
OR TELEPHONE CONDUCTORS." A communication from abroad by John
Milton Stearns, junior, of Brooklyn, in the United States of America.
PROVISIONAL SPECIFICATION left by the said John Imray at the Office
of the Commissioners of Patents on the 14th December 1881.
JOHN IMRAY, of No. 28, Southampton Buildings, in the County of Middlesex.
"IMPROVEMENTS IN TELEGRAPH OR TELEPHONE CONDUCTORS." [A communication
from abroad by John Milton Stearns, junior, of Brooklyn, in the United States of
America.]
This Invention relates to the construction and arrangement of cables or grouped
conductors for telegraphs or telephones, in such a manner as to prevent the
interferences resulting from induction which the passage of an electric current
along any one of the group causes in others of the group lying closely adjacent to
it. For this purpose a thin sheet of metal such as copper, having high conductivity,
is folded up along with the insulated conductors in a zig-zag manner, so that
portions of this metal are everywhere interposed between each insulated conductor
and those next to it. This metal sheet being at numerous points connected
electrically to earth or other discharging conductor, or to the metal pipe in which
such cables are often enclosed, carries off induced currents so that the passage of
electricity through any of the grouped conductors does not induce currents in
others of the group. Sometimes the insulated conductors are carried in parallel
lines along the wall; in such a case the metal sheet can be folded to and fro and
passed either in single or in double folds between each adjacent pair and partly
round each, and finally over the whole. When the conductors are grouped so as
to form a cable, the sheet can in like manner be so undulated or zig-zagged as to
form a series of loops each enclosing one of the conductors which is thus separated
by metal from those adjacent to it.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Imray in the Great Seal Patent Office on the 5th June
1882.
JOHN IMRAY, of. No. 28, Southampton Buildings, in the County of Middlesex.
"IMPROVEMENTS IN TELEGRAPH.OR TELEPHONE CONDUCTORS." A communication
from abroad by John Milton Stearns, junior, of Brooklyn, in the United States of
Ainerica.
This Invention relates to the construction and arrangement of cables or grouped
conductors for telegraphs or telephones in such a manner as to prevent the
interferences resulting from induction, which the passage of an electric current
along any one of the group causes in others of the group lying closely adjacent .to
it. For this purpose a thin sheet of metal such as copper, having high conductivity,
is folded up along with the insulated conductors in a zig-zag manner, so that
portions of this metal are everywhere interposed between each insulated conductor
and those next to it. This metal sheet being at numerous points connected
electrically to earth or other discharging conductor, or to the metal pipe in which
such cables-are-often-enclosed, carries-off-induced-currents-so-that-the-passage-of-
electricity through any of the grouped conductors does not induce currents in others
of the group.
Sometimes the insulated conductors are carried in parallel lines
along a wall; in such a case the metal sheet can be folded to and fro and passed
either in single or in double folds between each adjacent pair and partly round each,
and finally over the whole. When the conductors are grouped so as to form a
cable, the sheet can in like manner be so undulated or zig-zagged as to form a
series of loops, each enclosing one of the conductors which is thus separated by
metal from those adjacent to it.
The accompanying Drawings shew diagrammatically to an enlarged scale some
of the various ways in which the metallic sheet may be folded along with conductors
for the purposes of this Invention. In Fig 1, shewing 4 conductors, A, B, C, and D,
arranged side by side, the metal sheet Al is undulated so as to interpose itself
between each successive pair; Fig. 2 illustrates the undulatory folding of the
sheet M to interpose between conductors A, B, C, &c., circularly arranged. When
the conductors are arranged in a vertical row along a wall, the sheet M may be
folded as illustrated by Figs. 3 and 4. When the conductors are grouped to form a
cable within an enclosing pipe, the sheet M may be folded as illustrated by Fig. 5.
It is of advantage to carry the sheet round so as to enclose the whole, as indicated
in Figs. 4 and 5.
Having thus described the nature of the said Invention, and in what manner
the same is to be performed, as communicated to me by my foreign correspondent,
I hereby declare that. I make no general claim to the use of external metal
coverings in connection with grouped insulated conductors, but I claim,--
The combination with a number of grouped insulated conductors of a metal
sheet folded with and among them, so as to interpose itself between those that are
adjacent to each other, and connected to earth or an equivalent discharge, so as to
carry off induced currents, substantially as herein described.
In witness whereof, I, the said John Imray, have hereunto set my hand
and seal, this Fifth day of June, in the year of our Lord One thousand
cight hundred and eighty two.