Improvements in Autographic Telegraphs.
Year: 1889

page_text: Date of Application, 10th Jan., 1889
Complete Specification Left, 10th Oct., 1889-Accepted, 10th Jan., 1890
PROVISIONAL SPECIFICATION.
Improvements in Autographic Telegraphs.
I, AMBROSE MYALL, of 21 Cockspur Street, in the County of Middlesex, Civil
Engineer, do hereby declare the nature of this invention, which has been
communicated to me from abroad by Walter Judd of Hong Kong, Electrician, to be
as follows:-
In autographic or writing telegraphs, as heretofore ordinarily constructed, that is
to say such telegraphs for example as Cowper's and Robertson's, wherein the hand-
writing of the operator at the transmitting instrument is reproduced by the receiving
instrument, it is necessary to employ a double line wire, and the object of my invention
is to provide a means whereby such telegraphs can be worked upon a single line wire.
To effect such object I employ the harmonic commutator for converting alternating
into continuous currents, as described in my application for Letters Patent, No. 4294
of 20th March 1888.
In the Cowper and Robertson telegraphs there are two sets of resistances connected
with the stylus of the transmitting instrument and two sets of coils connected with the
pen of the receiving instrument. One of these resistances is connected by one line
wire with one of the receiving coils, and the second resistance connected to the second
coil by the second line wire.
In applying my harmonic commutator to instruments of the above class, I send a
constant or solid" current through the first resistance on the transmitter, and a
current of the same potential through the second resistance and through an interrupter,
these two currents are both sent down a single line wire, so that there are a "solid"
and a vibratory current both traversing the line.
At the receiving end both currents pass through the primary coil of a transformer,
or induction coil, and then through the first coil of the receiving instrument to earth.
The secondary coil of the transformer is not affected by the "solid" current, but
alternating currents are produced in it by the vibratory current. These alternating
currents are passed through a harmonic commutator and there converted into a
continuous current, which is caused to operate the second coil of the receiving
instrument. The commutator is set in motion from the vibratory current by means
of electro-magnets inserted in the line wire.
The resistances on the transmitter may be varied in any of the known or other
suitable methods, and the varying currents thus obtained will actuate the receiver in
the same manner as when a double line is employed. The great advantages attendant
on being able to work these instruments upon a single line are quite obvious. In
addition to combining my harmonic commutator with autographic telegraphs, I also
employ, when required, suitable devices which cause the pen of the receiving instrument
to break contact with the paper when the stylus at the transmitter is lifted off the
paper. This arrangement is specially valuable in copying sketches, or in sending
messages in characters which cannot be formed by a continuous line, as for example
Chinese characters. It also enables the words of a message sent in English, or similar
characters, to be detached instead of joined by a line as heretofore.
Dated this 10th day of January 1889.
AMBROSE MYALL,
21, Cockspur Street, London, S.W.

page_text: COMPLETE SPECIFICATION.
Improvements in Autographic Telegraphs.
I, AMBROSE MYALL, of 21 Cockspur Street, in the County of Middlesex, Civil
Engineer, do hereby declare the nature of this invention which has been communi-
cated to me from abroad by Walter Judd, of Hong Kong, Electrician, and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement :-
In autographic, or writing telegraphs, as heretofore ordinarily constructed, that is
'to say, such telegraphs for example as Cowper's and Robertson's, wherein the hand-
writing of the operator at the transmitting instrument, is reproduced by the receiving
instrument, it is necessary to employ a double line wire, and the object of my
invention, is to provide a means whereby such telegraphs can be worked upon a single
line wire. To effect such object, I employ a harmonic commutator, for converting
alternating, into continuous currents, as described in my Letters Patent No. 4294 of
20th March 1888.
In the Cowper, and Robertson, writing telegraphs, there are two sets of resistances
connected with the stylus of the transmitting instrument, and two sets of coils
connected with the pen of the receiving instrument. One of these resistances
is connected by one line wire with one of the receiving coils, and the second resistance
connected to the second coil by the second line wire.
In applying my harmonic commutator to instruments of the above class, I send a
constant or "solid" current through the first resistance on the transmitter, and a
current of the same potential through the second resistance, and through. an
interrupter, these two currents are both sent down a single line wire, so that there are
"solid' and a vibratory current both traversing the line.
a
At the receiving end both currents pass through the primary coil of a transformer,
or induction coil, and then through the first coil of the receiving instrument to
earth.
The secondary coil of the transformer, is not affected by the "solid" current, but
alternating currents are produced in it, by the vibratory current. These alternating
currents, are passed through a harmonic commutator, constructed in accordance with
my aforesaid Letters Patent, and there converted into a continuous current, which is
caused to operate the second coil of the receiving instrument. The commutator is set
in motion from the vibratory current, by means of electro-magnets, inserted in the
line wire.
The resistances on the transmitter, may be varied in any of the known, or other
suitable methods, and the varying currents thus obtained, will actuate the receiver in
the same manner as when a double line is employed.
The accompanying drawing represents diagrammatically the application of my
harmonic commutator, to a writing telegraph
--
Fig. 1 is the transmitting, and Fig. 2 the receiving apparatus. The message to be
sent, is written upon a moving strip of paper B, by a stylus A. The paper is caused
to travel forward, by clockwork, or other suitable means. This stylus, by means of
the rods D D¹, varies the resistances (C. The stylus is connected to earth by the
wire K. By means of the battery L, a constant, or "solid" current, is sent through
the resistance C, and by means of the battery L, a current of the same potential, is
sent through the resistance C, the current through C, goes direct to the single line
wire M, but the current through C, passes first through an interrupter N, and then goes
down to line, so that there are two distinct currents passing down the line M, a
solid," and a vibratory current.
"
At the receiving station, both currents pass through the electro-magnets E E, of
the harmonic commutator R, then through the primary coil of the transformer, or
induction coil T, then through one of the coils H, of the receiving instrument, and to
earth through the wire K'.

page_text: The secondary coil of the transformer, is not affected by the "solid" current, but
alternating currents are produced in it, by the vibratory current. These alternating
currents, pass through the contacts cccc, of the harmonic commutator R, and
are there converted into a continuous current, as described in my aforesaid Letters
Patent No. 4294 of 1888; this continuous current traverses the circuit P, and
operates the second coil H', of the receiving instrument. The coils H H³, by means
of the connections J J', operate the pen Q, so that its movements correspond with
those of the stylus A, and the message is delivered upon the travelling strip of
paper F.
The resistances C C¹, may be of any suitable description, and may be varied by
any of the known, or other suitable methods, and the varying currents thus obtained,
and sent down the single line M, will actuate the receiving coils. H H', in the same
manner, as when a double line is used, with two "solid" currents.
In addition to combining my harmonic commutator, with autographic telegraphs,
I also employ when required suitable devices, which cause the pen of the receiving
instrument to break contact with the paper, when the stylus at the transmitter is lifted
off the paper. This arrangement is specially valuable in copying sketches, or in
sending messages in characters which cannot be formed by a continuous line, as for
example, Chinese characters. It also enables the words of a message sent in English,
or similar characters, to be detached, instead of joined by a line as heretofore.
A
The arrangements which I employ for this purpose are as follows. When the
stylus A is raised from the paper B, currents from only a certain number of the
battery cells go to line, but when the said stylus touches the paper, a contact is made
which increases the current by bringing into action the remainder of the cells.
method of arranging the said contact is by causing the paper B to pass over a hinged
stage, at the point where writing is performed, this stage is ordinarily raised by a
light spring, but the pressure caused by writing depresses the stage, which makes a
contact, joining up the rest of the cells. Any other suitable means may however be
employed for effecting the said contact. The paper at the receiving end passes
over a stage at the writing point, which said stage can be made to rise or fall, by
means of an electro-maguet, thus bringing the paper in, or out of contact with the
pen Q. The line current passes through the said electro-magnet. When the stylus A
is raised out of contact with the paper B, the smaller current passes, as before
explained, and this current is not sufficient to actuate the said electro-magnet, so that
the stage under the paper F, does not rise and the pen Q is consequently out of
contact with the paper F, but when writing commences at B, the stronger current,
which is then put on, actuates the electro-magnet causing it to raise the paper F into
contact with the pen Q.
The stronger current, in addition to raising the paper F, also gives extra power to
the coils HH', enabling them to overcome more readily the friction between the
pen and the paper. If the stylus A be moved out of contact with the paper B, the
smaller current will be sent, and it is obvious therefore that the pen Qwill follow
the movements of the stylus without recording them on the paper F, but when writing
begins at B, the work will be reproduced on the paper F.
For ordinary writing, the strips of paper may be moved by clockwork in the
ordinary way, but for transmitting Chinese characters, sketches, or similar work, both
papers must be capable of remaining stationary or moving forward_synchronously,
step by step, of the will of the operator at the transmitting station. Such a step by
step motion, may be obtained by moving each strip by means of ratchet device, the
ratchets being operated by electro-magnets, which respond to a reversed current to
that used for signalling, or the said electro-magnets may be caused to be operated by
cutting off the signalling current altogether.
It will be understood that the arrangement shewn in the drawing is merely
diagrammatic, and that such an arrangement may be modified in certain details,
without departing from the essential principles of my invention.
I have not shewn in the drawing any device for regulating the speed of the
harmonic commutator, but the solenoid operating a plunger in a cistern of mercury,

page_text: shewn and described in my aforesaid Letters Patent, No. 4294 of 1888 may be
employed, or any other device which will answer the required purpose.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed i declare that what I
claim is :-
1. The combination,.. with an autographic or writing telegraph, of the harmonic
commutator described in my aforesaid Letters Patent No. 4294 of 1888 for enabling
the said telegraph to be worked upon a single line wire, substantially as herein sel
forth.
2. An autographic or writing telegraph, having solid and vibratory currents, both
traversing a single line wire M, the two currents at the receiving station passing
through the coils EE of a harmonic commutator R, the primary coil of a transformer
or induction coil T, and one of the receiving coils H, the vibratory current being
transformed by the harmonic commutator into a continuous current and operating
the other receiving coil H', substantially as herein described and shewn.
3. In an automatic or writing telegraph, the arrangement for causing the paper F
to leave the receiving pen Q when the sending stylus A is lifted from the paper B,
substantially as herein described.
4. In an automatic or writing telegraph, having the arrangement described in the
preceeding claim, the device for giving a step by step motion to the paper at the will
of the operator, substantially as herein set forth.
Dated this 10th day of October 1889.
AMBROSE MYALL,
21, Cockspur Street, S.W.