IMPROVEMENTS IN ELECTRIC PRINTING TELEGRAPHS."
Year: 1874

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane,
in the County of Middlesex, Patent Agent, for the Invention of
"IMPROVEMENTS IN ELECTRIC PRINTING TELEGRAPHS."-A communication
from abroad by Ludovic Charles Adrien Joseph Guyot d'Arlincourt,
of Paris, France.
Sealed the 9th March 1875, and dated the 22nd September 1874.

page_text: Patent bearing date January 25, 1873, 255. The principle of this
electro-magnet consists as specified in the above mentioned Letters
Patent in the complete reversal of the magnetism produced by the
current on the breaking of this current by placing the armature or
pallet at the butt end. With this object I apply to an electro-magnet &
two pallets, the one at the pole end and the other at the butt end or
back piece, whereby the two pallets are caused to move symmetrically
during the passage of alternate currents, and on the breaking of any one
of these currents they assume a dissymetrical position.
2ndly. The Invention consists in the application of a second armature
placed at the butt end of the electro-magnet, having the same functions
as the one with which it is combined, and both operating by the
same pole of an electro-magnet to facilitate the adjustment of the
impression.
Figures 1 and 2 of the accompanying Drawings show front and edge
views of this electro-magnet for receiver with two armatures at the butt
end. a, a, a¹, a¹, coils of the electro-magnet; b, armature at free ends of
the limbs; c, d, armatures at the butt end.
3rdly. The Invention consists in the employment of two supplementary
coils a, a, placed on the other side of the armature b, whereby an
electro-magnet having great rapidity of action is obtained since the
residuary magnetism acting on the armature 6 is completely neutralized.
4thly. The Invention consists of an improvement in transmitters of
the kind shown in face view Figure 3, with the object of obtaining
continuous currents along the line. It is known that in a transmitter
with the ordinary reversing action at the instant that the contact springs
pass from the positive current to the negatve current there is a dead
point, that is to say, a cessation of the current. To avoid this I cause
the contact lever e to vibrate by sharp sudden jerks, so that the dead
point becomes nil since the contacts f, f, always touch on one side or a
the other. For this purpose instead of keying the sinuous wheel g on
the spindle of the manipulator h as usual, I allow a little play of the
axis i of the handle on which the wheel g is keyed, the latter being
serrated, as shown at the circumference at j, against which runs a
friction roller k fixed at the extremity of a spring blade l. By this
means when the handle is turned the roller k will first be forced back
by the inclined side of a tooth, as shown in Figure 4, and then when the

page_text: roller has arrived at the apex of the tooth the spring blade will press
the roller against the other inclined side of the same tooth, and the
roller with thus instantaneously force forward the sinuous wheel ga
certain distance in advance of the rotary movement of the handle h, as
indicated in dotted lines Figure 5, thus avoiding any breaking of contact
of the springs on either side.
5thly. The Invention consists of improvements hereafter described in
printing telegraphs used in a special system of telegraphy employed for
short distances. In this case two and even three wires have been used,
the one serving specially to actuate the receivers the second for actuating
the printing mechanism, and the third for bringing the instruments to
the ☑or stop.
The improvement consists in the means of controlling by one of the
wires the action of all the receivers connected with the other wire. As
an example, I will take an apparatus with two wires, of which one
serves for the printing and the other for actuating the receivers.
A, A¹, A, A1, Figure 6, are metal discs fixed on the axis of the
type wheels of the receivers; R, R', R", R¹¹¹, are contact springs which,
on touching the discs A, A', A", A, close the circuit of the electro-
printers E, E, E", E. Thus it will be seen that so long as springs R,
R, R, R, touch the discs A, A', A", A, the printing may be effected
by depressing the handle of the transmitter M, which by this means sends
the current of battery P simultaneously through the electros E, E¹,
E", E. Now if the handle M be raised in order to move it round to
another letter on the dial this transmitter is so arranged that the
current of the printing battery P is broken and the current of the small
battery is introduced in the same circuit, and before passing to the
electros it passes through and actuates an alarm s, although it is not of
sufficient strength to actuate the electros and produce an impression.
On each of the discs A, A', A", A", is a small insulated part a, a¹,
a", a, corresponding to the ☑or stop.
or stop. The printing circuit is thus
broken simultaneously at cach point when the springs R, R', R", R¹¹¹,
touch the insulated parts a, a, a¹¹, a¹¹¹, At this moment the alarm bell
is sounded once. It will thus be readily understood that if one of these
receivers becomes disarranged, and the interruption a of the first
receiver does not correspond with that of the second or any other one,
the printing circuit will be broken and the alarm will sound during the

page_text: rotation of the manipulator handle as many times as there are receivers
disarranged. Thus the operator will be informed at each rotation and
at each instant of the disarrangement of any one of the apparatus
connected with the wire of the receiver.
Whenever one of the apparatus is disarranged they are all made to set
themselves to the or stop which is effected without the aid of a
third wire in the following manner:-The manipulator handle M is
turned three times round the dial without printing, that is to say,
without being dropped into any of the notches, whereby the type wheel
will be turned three times. This type wheel I, Figure 7, after being
thus thrice rotated is arrested by a finger d corresponding to the
stop being caught by the catch c which is fixed on a lever N, O, P,
oscillating on an axis at O in the direction of the arrow f at each
impression. Thus when the printer acts, the part P, c, is raised suddenly
and releases the finger d. The pinion V will turn freely in the teeth of
wheel x, in its upward movement, but is prevented from dropping by
the spring pawl u which will not allow it to turn in the contrary
direction, so that it is the wheel × which gradually allows the
part O, P, and c, to drop until the first impression takes place, since
the latter is raised each time to its maximum height. This gradual
descent of pinion V is so calculated that the finger d will only be
arrested after three turns, and as in operating the printer acts at least
once for each turn it will be seen that the finger d will never be arrested
whilst transmitting, but only when it is desired to bring the instruments
21.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Melville Clark in the Great Seal Patent
Office on the 19th March 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex, 3
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of September, in the year

page_text: of our Lord One thousand eight hundred and seventy-four, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Alexander Melville Clark, Her special
licence, that I, the said Alexander Melville Clark, my executors,
administrators, and assigns, or such others as I, the said Alexander
Melville Clark, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Inven-
tion for "IMPROVEMENTS IN ELECTRIC PRINTING TELEGRAPHS," a communication
to me from abroad by Ludovic Charles Adrien Joseph Guyot d'Arlincourt,
of Paris, France, upon the condition (amongst others) that I, the said
Alexander Melville Clark, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Alexander Melville Clark, do
hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the two
Sheets of Drawings hereunto annexed, and to the letters and figures
marked thereon (that is to say) :—
This Invention relates to improvements in printing telegraphs, and
consists,-
1st. In the particular application to dial printing telegraphs of the
principle of the electro-magnet relay, for which I obtained Letters
Patent bearing date January 25th, 1872, No. 255. The principle of
this electro-magnet consists, as specified in the above mentioned Letters
Patent, in the complete reversal of the magnetism produced by the
current on the breaking of this current by disposing the armature or
pallet at the end opposed to the poles, which I term the butt end.
For
this purpose I provide an electro-magnet with two pallets, the one at
the pole end, and the other at the opposite or butt end; and these two
pallets are thus caused to move symmetrically during the passage of

page_text: alternate currents, and on the breaking of any one of these currents they
assume a dissymetrical position.
2ndly. The Invention consists in the application of a second armature
or pallet at the butt end of the electro-magnet having the same functions
as the one with which it is combined, and both actuated by the
same pole of an electro-magnet to facilitate the adjustment of the
impression.
Figures 1 and 2 of the accompanying Drawings show front and edge
views of this magnet for receiver provided with two armatures at the
butt end. a, a, a¹, a¹, coils of the electro-magnet; b, armature at the
poles; c, d, armatures at the opposite end of the magnet.
3rdly. The Invention consists in the employment of two supple-
mentary coils a¹, a¹, placed on the other side of the armature of the
receiver, whereby an electro-magnet having great rapidity of action is
obtained, since the residuary magnetism acting on the armature 6 is
completely neutralized.
4th. The Invention relates to transmitters of the kind shown in
face view, Figure 3, and consists in a modification having for object
to obtain continuous currents along the line. It is known that in a
transmitter with the ordinary reversing action, at the instant that the
contact springs pass from the positive current to the negative current
there is a dead point, that is to say, a cessation of the current. To avoid
this I cause the contact lever e to vibrate by sharp sudden jerks, so that
the dead point becomes nil, since the contacts f, f, always touch on one
side or the other. For this purpose instead of keying the sinuous wheel g
on the spindle of the transmitter h as usual, I allow a little play of the
axis of the handle on which the wheel g is keyed, the latter being
serrated, as shown at the circumference at j, against which runs a friction
roller k fixed at the extremity of a spring blade 1. By this means when
the handle is turned the roller k will first be forced back by the inclined
side of a tooth, as shown in Figure 4, and then when the roller has
arrived at the apex of the tooth the spring blade will press the roller
against the other inclined side of the same tooth, and the roller will
thus instantaneously force forward the sinuous wheel g a certain distance
in advance of the rotary movement of the handle h, as indicated in
dotted lines, Figure 5, thus avoiding any breaking of contact of the
springs fon either side.

page_text: 5thly. The Invention consists of improvements, hereafter described, in
printing telegraphs used in a special system of telegraphy generally
employed for short distances, and in which a number of apparatus are
employed, all controlled by the same transmitter. In this case, two, and
even three, wires have been used, the one serving especially to actuate
the receivers, the second for actuating the printing mechanism, and the
third for bringing the instruments to the zero or starting point.
The improvement consists in the means of controlling by one of the
wires the action of all the receivers connected with the other wire. As
an example I will take an apparatus with two wires, of which one serves
for the printing, and the other for actuating the receivers.
A, A', A", A, Figure 6, are metal discs fixed on the axes of the type
wheels of the receivers; R, R¹, R¹, R¹¹, are contact springs, which, on
touching the discs A, A', A", A", close the circuit of the electro-
printers E, E', E", E". Thus it will be seen that so long as springs
R, R¹, R", R, touch the discs A, A', A", A", the printing may be
effected by depressing the handle of the transmitter M, which by this
means sends the current of battery P simultaneously through the
electros E, E¹, E", E". Now if the handle M be raised in order to move
it round to another letter on the dial this transmitter is so arranged that
the current of the printing battery P is broken and the current of the
small battery is introduced in the same circuit, and before passing to
the electros it passes through and actuates an alarum S; but it is not of
sufficient strength to actuate the electros and produce an impression.
On each of the discs A, A', A", A, is a small insulated part a, a¹,
a, a, corresponding to the zero point. The printing circuit is thus
broken simultaneously at each disc when the springs R, R', R", R¹¹¹,
touch the insulated parts a, a¹, a", a¹¹¹. At this moment the bell is
sounded once. It will thus be readily understood that if one of these
receivers becomes disarranged, and the interruption a of the first
receiver does not correspond with that of the second or any other one,
the printing circuit will be broken and the alarm will sound as many
times during one turn of the manipulator handle as there are receivers
disarranged. Thus the operator will be informed at each turn, and at
each instant, of the disarrangement of any one of the apparatus con-
nected with the wire of the receiver.
Whenever one of the apparatus is disarranged they are all made to
set themselves to the zero or common starting point, which is effected

page_text: the transmitter handle three times round the dial without printing in
order to set the instruments to zero.
The worm n which moves arm o horizontally is of such a pitch that
after three turns of the transmitter bandle (or of the type wheel), the
stop 8 of said arm will be in the path of the arm c (at which moment
also the zero of type wheel a will be opposite the printing roller e), and
the said finger c will abut against said stop s, and the motion of type
wheel will be arrested as well as that of shaft m and its worm n. In
order to return arm o to its original position and allow of the type wheel
turning, it is only necessary to bring up the printing lever fas if for the
purpose of printing a letter. The lever in rising pushes upwards pin 7,
thereby oscillating shaft n and disengaging arm o from the thread of
worm n, whereupon the said arm is drawn back by spring t against the
shoulder 1, and the type wheel is free to turn. As in practice the
instrument prints at least once in every revolution of the transmitter,
and the worm is calculated to stop the type wheel only after three turns
without printing, it is evident that the arm c will never be arrested
during the transmission of a message, as the arm o is returned to its
first position each time a letter is printed. Thus perfect synchronism
may be obtained between the transmitter and receiver, as both instru-
ments may be brought simultaneously to the starting point.
In describing the apparatus illustrated in Figure 6 of the Drawings, it
was stated that the second circuit for actuating the printing electro-
magnets E, E", E", passed through the springs R, R', and metal discs
A, A', and was interrupted at the starting point by the insulated parts
A, A', and it has also been explained how on this interruption of the
current the bell S indicates that all the instruments are in synchronism
by sounding once only at a revolution of the transmitter handle, whereas
if one or more of the instruments were not synchronous with the others
the bell would be sounded two or more times at each turn according to
the number of instruments out of order.
The following relates to an improvement or modification of the above
apparatus, enabling the same result to be obtained by the passage of the
current instead of by its interruption. In this case the parts a, a¹, form
metallic contacts, while the rest of the surface of the discs A, A', is
insulated. This modified arrangement, which is illustrated in Figure 10
of the Drawing, possesses the advantage-1st. Of avoiding the resistance

page_text: 0
of the springs R, R', which made contact more or less perfectly with the
discs A, A¹, whereas by the new arrangement the printing circuit is
always closed directly. 2nd, Of enabling the receivers to be returned
to the standing point electrically by the passage of a reverse current,
since in this case there will be a closed circuit when the instrument is at
the starting point, whereas before it was open; and 3rd, That this
reverse current for returning the receivers to the starting point passes
through the electro-magnet or magnets only of those instruments which
are actually out of order.
The following is the method of controlling the apparatus:-During
the entire revolution of the type wheels keyed as before on the shafts of
the discs A, A¹, the small additional circuits e, R, a, A, u, are broken,
since the springs R, R¹, are in contact with the insulated circumference
of discs A, A', as shown in No. 2 apparatus; therefore when the handle M.
of the transmitter is dropped down into a letter on the dial the current
passes directly through the electro-magnets E, E¹, and the printing of
the corresponding letter takes place. When all the instruments are at
zero, and the springs R, R¹, therefore in contact with the metallic
parts a, a, the circuit will be derived at points c, c¹. As the derived
circuits e, R, a, A, u, have no resistance while on the other hand the
circuit C, E, C, E, passing through the printing electro-magnets has the
resistance of these electro-magnets, no current will pass by C, E, C¹, E³,
and therefore (all the instruments being at the starting point) the whole
circuit will have no resistance, and the current will pass through C, e,
R, α, A, u, C¹, e¹, R, a¹, A¹, u¹, et cætera, and not through the electro-
magnets. I therefore employ this means for controlling the working of
the instruments, and to this end I arrange an alarum to sound only when
there is no resistance in the circuit, and to cease working when there is
the smallest resistance, consequently the bell will not sound when any
one of the apparatus is not in order. Suppose for example this to be the
case with instrument No. 2, as indicated in the Drawing, the spring R¹
being no longer in contact with the metallic part a¹ the derived circuit
is broken and the current passes through the electro-magnet E¹, whose
resistance prevents the bell S sounding, and thus notifying that one or
more of the instruments is not in order. To bring all the instruments to
the starting point by electrical instead of by mechanical means as before
I send by any suitable means whenever one or even several apparatus are
in order a special reverse current, or it may be the printing current

page_text: reversed, which will so act on the electro-magnet or magnets of the one
or more apparatus which may be out of order as to bring these only to
the zero or starting point without affecting the other instruments, since
the current cannot pass through their electro-magnets, these latter
instruments being already at zero. This improved means of bringing
electrically the instruments to the starting point is thus based in
principle on the direct passage of the current employed for the purpose
through the electro-magnet or magnets of those instruments only which
are not in order, and I therefore claim the various means by which
the principle may be applied. By this method the current is only used
to set right those instruments which are not in order, which may be done
instantaneously without being obliged to rotate the handle of the trans-
mitter several times, as in the mechanical arrangements previously
described.
The following are two examples of the mode of carrying out this
principle in practice :-In the first arrangement, shown in Figure 11, in
place of the worm used for bringing arm o opposite arm c of the type
wheel a I employ a fixed piece having two notches M, M', by which the
arm o is held in two positions, it being brought to the upper position on
notch M by the spring t, and to the lower position in notch M¹ by the
electro-magnet N through the medium of the pallet p, which presses the
part o into the stop. Thus it will be seen that the type wheel is arrested
by electrical and not by a mechanical action. The electro-magnet N is
made of the form shown, and has at its poles prolongations A, B, placed
on either side of pallet p to oscillate this pallet from one to the other.
In the one position the pallet presses against the pin f of arm o, while
in the other the arm o being raised by the action of the printing roller e
is set free from the notch M' and is drawn back by spring t on to notch M,
which is its position of rest.
Figure 12 shows another arrangement for effecting the same result by
electrical means. In this case the pallet p of electro-magnet N being of
suitable form itself acts as a stop to the pin c of the type wheel a. When
the reverse current for bringing an instrument to the starting point is
transmitted the pallet remains held against the pole A of the electro-
magnet in the position indicated in dotted lines, so as to bring it within
the path of the pin e and arrest the same. When the current is
interrupted the pallet is attracted by the pole B, and liberates the
pin c.

page_text: Having described the nature of the Invention and the manner of
performing the same, I declare that what I claim as the Invention to be
protected by the herein-before in part recited Letters Patent is,-
1st. The particular application to dial printing telegraphs of an electro-
magnet acting on the principle herein-before referred to, by which the
magnetism is completely reversed after each passage of the current, as
specified.
2ndly. The combination with the said electro-magnet of a second
armature or tongue disposed at the end opposed to the poles of the
electro-magnet, as and for the purpose specified.
3rdly. The employment in combination with the said electro-magnet
of two supplementary coils placed on the other side of the armature of
the receiver for demagnetizing the electro-magnet, as specified.
.
4thly. The employment in dial transmitters of a spring roller pressing
against angular teeth on the periphery of the sinuous wheel and
actuating the same wheel, for the purpose of obtaining a constant current
'on the line, substantially as shown and described.
5thly. In apparatus operated by several wires from the same trans-
mitter, I claim, 1st, controlling the working of the apparatus electrically
by means of the apparatus themselves and an alarum or other signal,
substantially as specified; and 2ndly, returning those apparatus only
which are out of order, to the common starting point by means of the con-
trolling apparatus, substantially as shown and described.
In witness whereof, I, the said Alexander Melville Clark, have
hereunto set my hand and seal, this Nineteenth day of March,
in the year of our Lord One thousand eight hundred and seventy-
five