IMPROVE- MENTS IN ELECTRIC TELEGRAPHS
Year: 1879

page_text: LETTERS PATENT to Edward Alfred Cowper, of No. 6, Great George Street,
Westminster, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN ELECTRIC TELEGRAPHS."
Sealed the 12th September 1879, and dated the 28th March 1879.
PROVISIONAL SPECIFICATION left by the said Edward Alfred Cowper at
the Office of the Commissioners of Patents on the 28th March 1879.
EDWARD ALFRED COWPER, of No. 6, Great George Street, Westminster, in the
County of Middlesex. "IMPROVEMENTS IN ELECTRIC TELEGRAPHS."
My Invention relates to the method of transmitting telegraphic signals for which
Lettors Patent were granted to me on the 15th June 1878, No. 2385.
According to this method the movements of a pen or style at the sending station
were caused to introduce varying resistances into two electric circuits connected
with the receiving station so that the varying currents in acting upon two electro-
magnets at the latter station caused these to impart movements in two directions at
an angle to each other to the receiving pen or style whereby this was made to repro-
duce the writing or characters produced by the sending pen. According to my
present Invention instead of making the movements of the style or pen introduce
varying resistances into the line circuit I cause them to produce greater or less
strength of current by bringing into the circuit a greater or less number of battery
cells or parts thereof; or instead of employing the direct currents from the batteries
or other sources of electricity I employ for the line circuit induced currents, varied
in strength by the movements of the style or pen, for which purpose it may be
connected to iron cores sliding longitudinally within solenoids, or to solenoids
sliding over fixed cores. The variation in the strength of currents sent into the line
circuit may also be effected by combining various numbers of battery cells with
various resistances in the following manner :-The contact bars worked by the
sending pen or style besides passing over successive plates connected through
various resistances to the line wire, as described in the Specification referred to, also

page_text: pass over successive plates respectively connected to various numbers of battery
cells, these two sets of plates being so arranged that at the one extreme of its stroke
the contact bar makes connection from the smallest number of cells to the greatest
resistance, and conversely. In the arrangement described in the Specification
referred to the receiving pen was connected by a system of threads or wires to two
horizontal soft iron cores or bars mounted on axes within fixed coils through which
the varying currents were passed, and situated between the poles of fixed magnets,
or the varying currents were passed through the coils of fixed electro-magnets so
that the varying movements of the said cores or bars were imparted through the
threads to the pen.
According to one of my present improvements I employ in place of this arrange-
ment a single moveable soft iron bar, tube, or needle which is connected directly to
and is in line with or parallel to the pen or style, being suspended between two fixed
electro-magnets or two sets of such magnets situated at a right or other angle to
each other, through the coils of which electro magnets the varying currents of the
two circuits are made to pass. The needle being connected to two springs acting
upon it in opposite directions to those in which the two sets of magnets act upon it
it will be seen that varying currents passing through the one magnet or set of
magnets will produce varying movements in the one direction in the needle, while
the varying currents passed through the other magnet or set of magnets will pro-
duce varying motions in the other direction at a right or other angle to the first,
and these motions being imparted directly to the pen or style will cause this to
reproduce the characters written by the sending pen. The suspension of the needle
Bo as to enable it to move in every-direction may either be effected by resting it on
a point or on a universal joint at any part of its length, or it may be suspended
from a spring or from a flexible thread or wire. It may be either rigidly fixed to
the pen or style, or the latter may be supported independently of the needle and be
so connected thereto that the pen is caused to reproduce the motions of the needle
in a more or less magnified manner. In order to render the cores of the fixed
electro-magnete as sensitive as possible to slight variations in the current I make
them of bundles of fine wires on thin plates in a manner well known. Instead of
employing a separate needle or separate needles, to which the pen is connected, the
pen itself may be pivotted or suspended vertically over the paper and have fixed on
it a piece of iron exposed to the varying attraction of electro-magnets in the two
directions, acting in opposition to springs pulling it in the opposite directions. The
elasticity of the pen itself may serve instead of such springs. In order that the pen
when it is pivotted may more easily traverse the surface of the paper it is of
advantage to give the paper, at the place where the pen moves over it, a concave
form coinciding nearly with the circular path in which the point of the pen moves
round its pivot. For this purpose I pass the paper under a bent plate with a hole
through it of sufficient size to allow of the largest excursions of the pen, the bend
of the plate giving the paper a certain amount of concave curvature at the place
where the pen moves over it. In order to secure the pen to the rods, strings,
needle, or bar which gives it motion I insert its lower end in a light spring clip, so
that it can be readily withdrawn therefrom when required, but is firmly held
thereby when in use. This clip may be made as a hole or slot in a light spring
admitting of a small amount of vertical motion so as to allow the pen to give to
inequalities of the paper. According to another improvement, which has for its
object to raise the pen from the paper when it ceases to write, and which is
applicable either to the above described arrangement or to that described in the
Specification of my previous Patent, I apply to the pen or style a spring acted on
by an electro-magnet or magnets, through the coils of which the currents of the two
circuits are made to pass, so that on the passing of such currents the pen is allowed
to descend by the action of the electro-magnets in opposition to the spring so as to
come in contact with the paper strip, while when the currents are caused to cease
by raising the sending pen on the completion of the word or character transmitted

page_text: the spring raises the pen out of contact with the paper, thereby causing each word
or character transmitted to be written separate from the other or others adjoining
it, as in ordinary writing. In place of raising and lowering the pen for the
above described purpose the surface over which the paper strip travels may be
made to rise and fall slightly, together with the paper, by the action of the
electro-magnet and spring.
I have described my method of transmitting telegraphic signals as being
worked by two separate electrical circuits, but it will be evident that by the appli-
cation of the well known "duplex" system a single circuit may be used for the
purpose, also that instead of using the currents from the line wire or wires direct
these may be made to operate relays at the receiving instrument in a well known
manner.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Alfred Cowper in the Great Seal Patent Office on the 26th
September 1879.
EDWARD ALFRED CowPER, of No. 6, Great George Street, Westminster, in the
County of Middlesex. "IMPROVEMENTS IN ELECTRIC TELEGRAPHS."
My Invention relates to the method of transmitting telegraphic signals for which
Letters Patent were granted to me on the 15th June 1878, No. 1385.
According to this method the movements of a pen or style at the sending station
were caused to introduce varying resistances into two electric circuits connected
with the receiving station, so that the varying currents in acting upon two electro-
magnets at the latter station caused these to impart movements in two directions
at an angle to each other to the receiving pen or style, whereby this was made to
reproduce the writing or characters produced by the sending pen. According to
my present Invention instead of making the movements of the style or pen
introduce varying resistances into the line circuit I cause them to produce greater
or less strength of current by bringing into the circuit a greater or less number of
battery cells or parts thereof. Or, instead of employing the direct currents from
the batteries or other sources of electricity, I employ for the line circuit induced
currents varied in strength by the movements of the style or pen, for which purpose
it may be connected to iron cores sliding longitudinally within solenoids or to
solenoids sliding over fixed cores. The variation in the strength of currents sent
into the line circuit may also be effected by combining various numbers of battery
cells with various resistances in the following manner. The contact bars worked
by the sending pen or style besides passing over successive plates connected through
various resistances to the line wire, as described in the Specification referred to, also
pass over successive plates respectively connected to various numbers of battery
cells, these two sets of plates being so arranged that at the one extreme of its
stroke the contact bar makes connection from the smallest number of cells to the
greatest resistance, and conversely. Each contact bar may be made to slide in
guides and have two projections on its under side, one sliding over a set of contact
plates connected to the resistance coils, and the other projection sliding over a set
of contact plates connected to the battery cells, and the pencil being connected to
each by a connecting rod, so that ns the operator writes battery cells are added and
resistance coils left out of the circuit when greater power is wanted; or battery
cells are left out and resistance coils are taken into the circuit when less power is
wanted. In the arrangement described in the Specification referred to the receiving
pen was connected by a system of threads or wires to two horizontal soft iron cores
or bars mounted on axes within fixed coils through which the varying currents
were passed and situated between the poles of fixed magnets; or the varying
currents were passed through the coils of fixed electro-magnets, so that the varying
movements of the said cores or bars were imparted through the threads to the
pen.
According to one of my present improvements I employ in place of this arrange-
ment a single moveable soft iron bar, tube, or needle which is connected directly to
and is in line with or parallel to the pen or style, being suspended between two
fixed electro-magnets or two sets of such magnets situated at a right or other angle
to each other, through the coils of which electro-magnets the varying currents of
the two circuits are made to pass. The needle being connected to two springs
acting upon it in opposite directions to those in which the two sets of magnets act
upon it, it will be seen that varying currents passing through the one magnet or
set of magnets will produce varying movements in the one direction in the needle,
while the varying currents passed through the other magnet or set of magnets will
produce varying motions in the other direction at a right or other angle to the first,
and these motions being imparted directly to the pen or style will cause this to

page_text: reproduce the characters written by the sending pen. The suspension of the needle
so as to enable it to move in every direction may either be effected by resting it on
a point or on a universal joint at any part of its length, or it may be suspended
from a spring or from a flexible thread or wire. It may be either rigidly fixed to
the pen or style, or the latter may be supported independently of the needle and be
80 connected thereto that the pen is caused to reproduce the motions of the needle
in a more or less magnified manner. In order to render the cores of the fixed
electro-magnets as sensitive as possible to slight variations in the current I make
them of bundles of fine wires or thin plates in a manner well known. Instead of
employing a separate needle or separate needles to which the pen is connected the
pen itself may be pivotted or suspended vertically over the paper and have fixed
on it a piece of iron exposed to the varying attraction of electro-magnets in the
two directions acting in opposition to springs pulling it in the opposite directions.
The elasticity of the pen itself or the needle which carries it may serve instead of
such springs. In order that the pen when it is pivotted may more easily traverse
the surface of the paper it is of advantage to give the paper at the place where the
pen moves over it a concave form coinciding nearly with the circular path in which
the point of the pen moves round its pivot. For this purpose I pass the paper
under a bent plate with a hole through it of sufficient size to allow of the largest
excursions of the pen, the bend of the plate giving the paper a certain amount of
concave curvature at the place where the pen moves over it. In order to secure
the pen to the rods, strings, needle, or bar which gives it motion I insert its lower
end in a light spring clip, so that it can be readily withdrawn therefrom when
required, but is firmly held thereby when in use. This clip may be made as a hole
or slot in a light spring admitting of a small amount of vertical motion so as to
allow the pen to give to inequalities of the paper. According to another improve-
ment, which has for its object to raise the pen from the paper when it ceases to
write, and which is applicable either to the above described arrangement or to that
described in the Specification of my previous Patent, I apply to the pen or style a
spring acted on by an electro-magnet or magnets through the coils of which the
currents of the two circuits are made to pass, so that on the passing of such currents
the pen is allowed to descend by the action of the electro-magnets in opposition to
the spring so as to come in contact with the paper strip, while when the currents
are caused to cease by raising the sending pen on the completion of the word or
character transmitted the spring raises the pen out of contact with the paper,
thereby causing each word or character transmitted to be written separate from the
other or others adjoining it, as in ordinary writing. In place of raising and
lowering the pen for the above described purpose the surface over which the paper
strip travels may be made to rise and fall slightly together with the paper by the
action of the electro-magnet and spring.
I have described my method of transmitting telegraphic signals as being worked
by two separate electrical circuits, but it will be evident that by the application of
the well known "duplex" system a single circuit may be used for the purpose;
also that instead of using the currents from the line wire or wires direct these may
be made to operate relays at the receiving instrument in a well known manner.
For example, by rapid alternations of current a single line wire may be arranged
to convey only positive impulses from one of the contact rods of the sending pen
to excite one of the electro-magnets of the receiving pen, the same wire being
arranged to convey only negative impulses from the other contact rod of the
sending pen to the other electro-magnet of the receiving pen. Or, according to a
known method depending on the correspondence of vibrations of tuning forks or
springs, each of the two electro-magnets may be made to receive the impulses only
from one of the bars of the sending pen. Although in the above description I
have referred to batteries as the source of electricity employed in the apparatus it
is to be understood that electricity from other sources, such as that produced by
magneto-electric or dynamo-electric machines may be applied to operate as set
forth.

page_text: DESCRIPTION OF THE DRAWINGS.
Fig. 1, Sheet I., is a plan, and Fig. 2, Sheet II., an elevation of an instrument
constructed according to my present Invention. a is the glass syphon receiving
pen suspended by a spring; b is a thin disc of soft iron, having a central hole, into
which is inserted a plug of cork or other suitable material c. The pen a fits into a
central hole in the plug c, and its lower end projects a short distance below the said
plug. The pen may fit the hole in the cork plug with sufficient friction to support
the weight of the plug and disc, and retain them in their proper position on the pen.
Or the pen may be a loose fit in the hole, and be retained in position by wax or
any suitable cement. d, e, are electro-magnets placed at right angles to each other,
each capable of moving the pen by attracting the disc b, which acts as an armature
to both. Each of these magnets is connected with one of the line wires. f. f. are
the fine springs, which supply the necessary resistance to the pen against the
pull of the magnets, the pen being connected to those springs by the threads f¹, ƒ³¹,
fff, f, the last two of which are attached to the post f'; g is the travelling
slip of paper, upon which the message is written by the syphon pen. It is driven
by clockwork or other suitable mechanical means at a uniform relative speed to the
paper in the sending instrument.
The sending apparatus shewn is similar in its construction to that described in
my former Specification above referred to. The currents from the two batteries
instead of being conveyed through wires fixed to the connecting rods attached to
the pencil are conveyed to the springs A', As, which bear upon the ends of the said
connecting rods respectively. A³3, A4, are small portions of insulating material, such
as wood or vulcanite. The resistance coils are formed of long continuous wires
wound on long bobbins h, Fig. 2, Sheet II. Connections are made by other short
wires from the long ends or tails of the contact plates to loops i formed on the
said continuous wires, and projecting at the suitable intervals.
Fig. 3, Sheet II., is an elevation, and Fig. 4 a plan of another form of the arma-
ture attached to the pen; is a piece of thin soft sheet iron, the lower end of which
is bent to the form of a right angle, and presents one of two flat faces to each of the
magnets o, p. Above the flat faces is a shank m of a trough like section, in the
hollow of which the pen can be placed. At the top of the shank m is a hole, into
which is inserted the end of the fine spring which supports the whole. At the
bottom is a spring clip to hold the pen in position, and near the top the pen is
steadied in the trough like shank by a ring of wire or string, or by cement.
Fig. 5, Sheet II., is an elevation, and Fig. 6 a plan of another modification of the
armature, the material and the form of the shank being the same as in that last
described. The lower end is in this case formed into a cylinder, from the upper
edge of which two narrow strips or tongues project inwards and downwards, forming
together a pair of clips to hold the pen in the axis of the cylinder. The shank is
bent or cranked just above the cylinder into the line of the pen.
Fig. 7 is an elevation, and Fig. 8 a plan drawn to an enlarged scale of another
form of armature differing from those above described in having no shank, being
supported solely by its attachment to the pen. This consists of a strip of sheet iron
bent into a cylinder, one end of the strip being extended inwards towards the axis
of the cylinder, where it is bent to form a trough like recess r, into which recess
the pen is pressed by a spring tongue or clip & projecting upwards from the lower
edge of the cylinder. In this case the pen itself is hung to the suspending spring
above, and the pressure of the clip is sufficient to sustain the weight of the light
armature. In each of the cases above described threads and springs similar to those
shewn in Figs. 1 and 2 or other convenient means are employed to resist the pull of
the magnets.
Another method of carrying out my Invention is shewn in Figs. 9 and 10,
Sheet II. In this arrangement the syphon
a tubulur section, which I call the needle.
interior of the needle through a hole in the
pen t is held by a bar of soft iron u of
vis a fixed bracket projecting into the
side thereof, and having a small hollow

page_text: at its extremity to receive a steel point fixed in the axis of needle. The neodle
thus supported is free to vibrate in any direction, and to move with it the pen t
which has its longer leg passed in through a hole in the side of the needle, and
projects out through another hole at the lower extremity of the same. The shorter
leg of the syphon dips into the ink reservoir w. x1, x, are stationary coils of wire
surrounding the needle u, of sufficient internal diameter to permit the required
amount of motion of the needle. A current passing through these coils magnetises
the needles.
y, y, y', y', are a set of stationary bar electro-magnets, which being in one circuit
always act together. Their poles are so arranged that when the needle is polarized
they all unite to deflect the needle to an inclined position in the plane in which
they are placed. 2, z, z, z¹, are a set of magnets precisely similar in their arrange-
ment and action, placed in a plane at right angles to the plane of the first set, and
producing a deflection of the needle in their own plane; f, f, are springs; f', f',
f, f, ff, are threads to give the necessary resistance to the needle against
the pull of the magnets, as in Figs. 1 and 2. The one set of stationary magnets
y, y, y', y¹, are connected to one line wire, and the other set 2, 2, 21, 21, to the other,
whilst a local battery is connected to the needle coils x1, x2, to keep the needle con-
stantly magnetised, as in one method of working the two needle instrument con-
structed according to the Specification above referred to.
As will be seen in Fig. 9 the paper g is made to pass under a curved plate gl, so
as to present to the pen a surface approximately corresponding to the arc in which
the point of the pen moves.
Another modification of the arrangement last described consists of a permanently
magnetised steel needle in place of that of soft iron, in which case the coils and the
local battery are not required; or the magnetism may be induced in the needle by
strong permanent magnets in close proximity to it.
Having thus described the nature of the said Invention, and in what manner the
same is to be performed, I claim,-
First. Effecting the variations of the force of the currents according to the move-
ments of the sending style or tracer by means of contact pieces connected thereto
and to the circuit, in such manner that according to the position of the tracer
varying numbers of battery cells or portions of cells are included in or excluded
from the circuit.
Second. Effecting the variations of the force of the currents according to the
movements of the sending style or tracer by means of contact pieces connected
thereto and to the circuit, in such manner that according to the position of the
tracer varying numbers of battery cells or portions of cells, and also varying resis-
tances are included in or excluded from the circuit.
Third. Working the receiving pen by a single needle, bar, or armature, subject to
the action of electro-magnets in the two directions, substantially as herein
described.
Fourth. The use,
for operating in the manner set forth in the preceding claim, of
apparatus constructed and arranged as herein described with reference to the accom-
panying Drawings.
Fifth. Curving the paper as it passes under the pen, substantially as and for the
purposes herein set forth.
In witness whereof, I, the said Edward Alfred Cowper, have hereunto set my
hand and seal, this Twenty sixth day of September, in the year of our
Lord One thousand eight hundred and seventy nine.
E. A. COWPER. (L.S.)