MENTS IN ELECTRIC TELEGRAPH CONDUCTORS AND APPARATUS FOR THEIR MANUFACTURE
Year: 1878

page_text: "
LETTERS PATENT to Charles William Siemens, of No. 12, Queen Anne's Gate,
Westminster, in the County of Middlesex, for the Invention of IMPROVE-
MENTS IN ELECTRIC TELEGRAPH CONDUCTORS AND APPARATUS FOR THEIR
MANUFACTURE."
Sealed the 22nd March 1878, and dated the 19th January 1878.
PROVISIONAL SPECIFICATION left by the said Charles William Siemens at
the Office of the Commissioners of Patents on the 19th January 1878.
CHARLES WILLIAM SIEMENS, of No. 12, Queen Anne's Gate, Westminster, in the
County of Middlesex. "IMPROVEMENTS IN ELECTRIC TELEGRAPH CONDUCTORS AND
APPARATUS FOR THEIR MANUFACTURE'
"
My Invention relates to a method of and apparatus for constructing electric
telegraph conductors in such a manner that the insulating material enclosing the
conducting wire or wires is directly protected by metallic sheathing, the whole
forming a protected insulated conductor, which may be used alone or which may con-
stitute a core to be covered with other protecting and strengthening material, such
as tape, hemp, or wire, twined or plaited thereon, according to any known system
of protecting and strengthening telegraphic conductors for land lines or submarine
cables. For this purpose, after covering the conducting wire or wires with
insulating materials, such as caoutchouc, gutta percha, and like substances in any
known manner, and to any desired thickness, I cause the continuous cylindrical
line thus formed to be drawn through the hollow mandril of a chuck, on which is
mounted a bobbin, or there may be several bobbins, charged with metallic tape,
that is to say, continuous, thin, and flexible strip of metal, such as copper. The
chuck with its bobbin or bobbins being made to revolve while the insulated con-
ductor is drawn onwards, the metallic tape is wound in helical form on the later,
and by suitably adjusting the speed of rotation to that of advance the successive
convolutions of the tape are made to overlap each other to a greater or less extent
as may be desired. The insulated conductor, as it is thus taped with metal, is drawn
[Price 6d.1

page_text: through a smooth die or between grooved pressing rollers, whereby the con-
volutions of the taping are closed firmly down and bedded in the insulating material
so as to constitute a kind of continuous metal tube or sheath for the insulated con-
ductor. The line thus formed may afterwards be taped or twined or plaited with
hemp or other like material and covered with wire in the usual way.
For the purpose of producing the strips of metal to be applied as above described
I employ apparatus of the following kind:-In a suitable framing I mount two
rollers geared together, the surfaces of these rollers being grooved so as to present a
number of circular chisel edges, so arranged that each edge on the one roller some-
what overlaps a corresponding edge on the other roller, these two edges thus con-
stituting a pair of revolving shear blades. At one side of these shearing rollers I
mount three or more plain rollers, between which a thin sheet of the copper or other
sheathing metal is passed, being thereby guided and flatted on its way to the
shearing rollers.
Beyond the latter I provide a number of spindles, on which are bobbins driven
by friction clutches at a speed somewhat exceeding that of the periphery of the
shearing rollers; and in front of these bobbins I provide guide eyes attached to a
slide which is caused to travel to and fro longitudinally by means of a revolving
spindle, on which is a right and left screw thread engaging with a stationary
blade.
The sheet of metal as it passes between the shearing rollers is divided longi-
tudinally into strips, each of which is led through one of the guide eyes above
mentioned to one of the bobbins facing it, on which the strip is wound in suc-
cessive convolutions as it is guided by the to-and-fro movement of the guide eye.
The bobbins thus charged with strip are taken to the sheathing apparatus above
described, whereby the strip is wound helically on the insulated conducting wire or
wires.
Conductors made with a large conducting core, such as is applicable for conveying
dynamo-electric currents to furnish light or power at moderate distances, are
advantageously sheathed as above described, the sheathing being available as the
return conductor.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles William Siemens in the Great Seal Patent Office on the 19th
July 1878.
CHARLES WILLIAM SIEMENS, of No. 12, Queen Anne's Gate, Westminster, in the
County of Middlesex. "IMPROVEMENTS IN ELECTRIC TELEGRAPH CONDUCTORS AND
APPARATUS FOR THEIR MANUFACTURE."
My Invention relates to a method of and apparatus for constructing electric
telegraph conductors in such a manner that the insulating material enclosing the
conducting wire or wires is directly protected by metallic sheathing, the whole
forming a protected insulated conductor, which may be used alone or which may
constitute a core to be covered with other protecting and strengthening materials,
such as tape, hemp, or wire twined or plaited thereon, according to any known
system of protecting and strengthening telegraphic conductors for land lines or
submarine cables. For this purpose after covering the conducting wire or wires
with insulating material, such as caoutchouc, gutta percha, and like substances
in any known manner, and to any desired thickness, I cause the continuous
cylindrical line thus formed to be drawn through the hollow mandril of a chuck,
on which is mounted a bobbin, or there may be several bobbins, charged with
metallic tape, that is to say, continuous, thin, and flexible strips of metal, such as
copper. The chuck with its bobbin or bobbins being made to revolve while the
insulated conductor is drawn onwards, the metallic tape is wound in helical form
on the latter, and by suitably adjusting the speed of rotation to that of advance
the successive convolutions of the tape are made to overlap each other to a greater
or less extent as may be desired. The insulated conductor, as it is thus taped with
metal, is drawn through a smooth die or between pressing rollers, whereby the
convolutions of the taping are closed firmly down and bedded in the insulating
material so as to constitute a kind of continuous metal tube or sheath for
the insulated conductor. The line thus formed may afterwards be taped or twined
or plaited with hemp or other like material and covered with wire in the
usual way.
For the purpose of producing the strips of metal to be applied as above described
I employ apparatus of the following kind:-In a suitable framing mount two
rollers geared together, the surfaces of these rollers being grooved so as to present a
number of circular chisel edges, so arranged that each edge on the one roller some-
what overlaps a corresponding edge on the other roller, these two edges thus con-
stituting a pair of revolving shear blades. At one side of these shearing rollers I
mount three or more plain rollers, between which a thin sheet of the copper or other
sheathing metal is passed, being thereby guided and flatted on its way to the
shearing rollers.
Beyond the latter I provide a number of spindles, on which are bobbins driven
by friction clutches, at a speed somewhat exceeding that of the periphery of the
shearing rollers; and in front of these bobbins I provide guide eyes attached to a
slide which is caused to travel to and fro longitudinally by means of a revolving
spindle, on which is a right and left screw thread engaging with a stationary
blade.
The sheet of metal as it passes between the shearing rollers is divided longi-
tudinally into strips, each of which is led through one of the guide eyes above
mentioned to one of the bobbins facing it, on which the strip is wound in successive
convolutions as it is guided by the to-and-fro movement of the guide eye. The
bobbins thus charged with strips are taken to the sheathing apparatus above
described, whereby the strip is wound helically on the insulated conducting wire or
wires.
Conductors made with a large conducting core, such as is applicable for conveying

page_text: DESCRIPTION OF THE DRAWINGS.
Fig. 1 shows a sectional side view of the apparatus for applying a metal sheathing
to the insulating covering of the conducting wires, as before described.
The cylindrical insulated conductor A passes through a fixed tube B situated
centrally in the revolving chuck C. This chuck carries one or more bobbins D,
having the metal tape A for the sheathing wound thereon. The tape A¹ is led
from the bobbin over an adjustable guide CI carried by the chuck, and is by the
rotary motion of the latter wound helically on the conductor A as this issues from
the die B' at the end of the tube B. As the tape is laid on the conductor it is
pressed firmly down by pressing blades E carried by adjustable brackets F, which
can slide in radial grooves on the face of the chuck. The outer edges of the brackets
have inclines, against which bear corresponding inclines on a ring G that can be
turned somewhat on the chuck by means of a worm H, so that by turning the ring
the brackets with their pressing blades can be moved inwards against the con-
ductor so as to act as a die pressing firmly thereon the metal sheathing. The
sheathed conductor then passes to a drum K moved by a worm and worm wheel
so as to draw the conductor through the sheathing apparatus at the required:
speed.
Figs. 2 to 5 shew the before described apparatus for cutting the strips of
sheathing metal from the sheet and winding the same on the bobbins; Fig. 2 is a
plan; Fig. 3 is an enlarged view of the two slitting rolls; Fig. 4 is a section
through the frame carrying the same.
The sheet metal L is passed over and under the guide rollers M and between the
slitting rolls N, N, which have a number of circular chisel edges N₁ at distances
apart corresponding to the width required for the metal sheathing tape, the edges
of the one roll overlapping those of the other, as shewn at Fig. 3, so that as the
sheet metal passes between them it is cut into corresponding narrow strips L', L',
which on issuing from the rolls are led to a series of bobbins D, these being the
same bobbins that are subsequently mounted on the sheathing machine before
described. These bobbins are placed loose upon a revolving shaft O, which drives
the bobbins by means of friction clutches P at a speed somewhat exceeding that of
the rolls N, so that the bobbins wind up the metal tape as it passes from the rolls.
Several shafts with their bobbins are arranged above each other and geared together
by spur wheels W so as to revolve at the same speed. The total number of bobbins
corresponds with the greatest number of strips L₁ cut by the slitting rolls. The
tapes on their way to the bobbins pass through guide eyes Q carried by a slide Q',
which is made to travel to and fro on a fixed bar R by means of a spindle S carried
by the slide and driven by a band from the drum H. On this spindle there is a
right and left screw thread S¹ engaging with a stationary pivotted blade S². Thus
the requisite lateral travel is imparted to the tape as it is wound in successive
layers upon the bobbin. Each eye Q carries a hinged arm Q³, having a guiding
loop at its end, through which the tape passes. The arm resting on the tape gives
a slight pressure, causing it to wind closely on the bobbin.
Having thus described the nature of my said Invention and in what manner the
same is to be performed, I claim,―
First. The use for sheathing an insulated electric conductor with metal of pressing
blades, in combination with taping apparatus, substantially as herein described with
reference to Fig. 1 of the accompanying Drawings.
Second. The use for the production of metal tapes for sheathing electric con-
ductors of apparatus wherein sheet metal is cut into narrow strips or tapes by
slitting rolls, from which the tapes are led through traversing guide eyes to bobbins

page_text: driven by friction clutches from shafts, on which they are loosely mounted, sub-
stantially as herein described with reference to Figs. 2 to 5 inclusive of the accom-
panying Drawings.
In witness whereof, I, the said Charles William Siemens, have hereunto set
my hand and seal, this Eighteenth day of July, in the year of our Lord
One thousand eight hundred and seventy-eight.
C. WILLIAM SIEMENS. (L.S.)