AN IMPROVED SYSTEM OF A DOUBLE TELEGRAPHIC TRANSMISSION
Year: 1877

page_text: LETTERS PATENT to Jules Xavier Eugène Sieur, of Provins (Se. et M.) France,
Electrician Engineer, for the Invention of "AN IMPROVED SYSTEM OF A
DOUBLE TELEGRAPHIC TRANSMISSION."
Sealed the 19th March 1878, and dated the 19th November 1877.
PROVISIONAL SPECIFICATION left by the said Jules Xavier Eugène Sieur
at the Office of the Commissioners of Patents on the 19th November 1877.
JULES XAVIER EUGÈNE SIEUR, of Provins (So. et Mo.), France, Electrician
Engineer. "AN IMPROVED SYSTEM OF A DOUBLE TELEGRAPHIC TRANSMISSION."
My Invention relates to a system of arranging and working electrical sending and
receiving instruments in connection with a line wire, such that the one wire is made
to serve for the transmission of two sets of messages or signals sent by two separate
operators working at the same time, and by combining this system with arrange-
ments for duplex telegraphing, the one line wire is rendered capable of quadruplex
working, that is to say, of conveying two sets of signals sent simultaneously from
each terminal station.
The principle on which my system is based will be best understood by description
of an arrangement of apparatus suitable for carrying it into operation. A cam,
eccentric, or its equivalent connected to earth, is caused by clockwork or other
suitable motor to revolve rapidly between two spring contact levers, the one of
which is connected to the positive and the other to the negative pole of a battery.
These levers are thus caused to oscillate rapidly to and from their respective con-
tacts, the one of which is connected to a contact for one operating key or sending
instrument, and the other to a contact for another such key or sending instrument.
Both these keys or senders are connected to the one line wire, which is thus made
to receive only positive currents from the one key or sender, and only negative
currents from the other, such currents being in each case intermittent, but suc-
ceeding each other rapidly. The line wire leads to a coil having a pair of polarised
armatures, or to a pair of polarised relays, the one of which is actuated by positive

page_text: currents and the other by negative currents, each operating a local battery in con-
nection with a receiving instrument. Thus the one receiving instrument being
affected only by positive currents imparts the signals transmitted from one of the
senders, and the other imparts those transmitted from the other sender.
As the positive and negative currents alternate, the one set of signals does not
interfere with the other set, and as the succession of impulses of either sign is rapid
the effect on each receiver does not practically differ from that produced by a con-
tinued current of the sign for which the receiver is adapted.
The sending and receiving instruments may be made to act as above described
when impulses are transmitted, or by suitable modification of the connections, sub-
stituting the breaking of circuit for the making of circuit, and vice versa, they may
be made to act by cessation of impulses. Also the motion for alternation, instead
of being introduced between the battery and the senders, may be introduced
between the senders and the line, the one sender being in connection with the
positive pole of a battery, and the other with the negative pole of another
battery.
By providing at the one end of a line an alternating motion with senders and
polarised relays, as I have described, and providing at the other end similar relays
and an arrangement of senders and connections similar to those employed for duplex
telegraphy, I am enabled to operate with the one line wire in quadruplex manner,
that is to say, to work the line as duplex for positive currents, and also as duplex for
negative currents, these separate operations being prevented from interfering with
one another by the alternation of the impulses, causing the complete suppression of
an impulse of the one sign, while an impulse of the other sign is being transmitted,
whilst yet the impulses of each sign succeed each other so rapidly that their alter-
nate suppression does not practically act as a cessation.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Jules Xavier Eugène Sieur in the Great Seal Patent Office on the 18th
May 1878.
JULES XAVIER EUGÈNE SIEUR, of Provins (Se. et M.), France, Electrician
Engineer. "AN IMPROVED SYSTEM OF A DOUBLE TELEGRAPHIC TRANSMISSION."
My Invention relates to a system of arranging and working electrical sending and
receiving instruments in connection with a line wire, such that the one wire is
made to serve for the transmission of two sets of messages or signals sent by two
separate operators working at the same time, and by combining this system with
arrangements for duplex telegraphing, the one line wire is rendered capable of
quadruplex working, that is to say, of conveying two sets of signals sent simulta-
neously from each terminal station.
The principle on which my system is based will be best understood by description
of an arrangement of apparatus suitable for carrying it into operation. A cam,
eccentric, or its equivalent, connected to earth, is caused by clockwork or other
suitable motor to revolve rapidly between two spring contact levers, the one of
which is connected to the positive and the other to the negative pole of a battery.
These levers are thus caused to oscillate rapidly to and from their respective con-
tacts, the one of which is connected to a contact for one operating key or sending
instrument, and the other to a contact for another such key or sending instrument.
Both these keys or senders are connected to the one line wire, which is thus made
to receive only positive currents from the one key or sender, and only negative
currents from the other, such currents being in each case intermittent, but succeeding
each other rapidly. The line wire leads to a coil having a pair of polarised arma-
tures, or to a pair of polarised relays, the one of which is actuated by positive
currents and the other by negative currents, each operating a local battery in
connection with a receiving instrument. Thus the one receiving instrument being
affected only by positive currents imparts the signals transmitted from one of the
senders, and the other imparts those transmitted from the other sender.
As the positive and negative currents alternate, the one set of signals does not
interfere with the other set, and as the succession of impulses of either sign is rapid,
the effect on each receiver does not practically differ from that produced by a con-
tinued current of the sign for which the receiver is adapted.
The sending and receiving instruments may be made to act as above described
when impulses are transmitted, or by suitable modification of the connections sub-
stituting the breaking of circuit for the making of circuit, and vice versa, they may
be made to act by cessation of impulses. Also the motion for alternation, instead
of being introduced between the battery and the senders, may be introduced
between the senders and the line, the one sender being in connection with the
positive pole of a battery, and the other with the negative pole of another
battery.
By providing at the one end of a line an alternating motion with senders and
polarised relays, as I have described, and providing at the other end similar relays
and an arrangement of senders and connections similar to those employed for duplex
telegraphy, I am enabled to operate with the one line wire in quadruplex manner,
that is to say, to work the line as duplex for positive currents, and also as duplex
for negative currents, these separate operations being prevented from interfering
with one another by the alternation of the impulses, causing the complete suppres-
sion of an impulse of the one sign, while an impulse of the other sign is being trans-
mitted, whilst yet the impulses of each sign succeed each other so rapidly that their
alternate suppression does not practically act as a cessation.

page_text: 40
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other convenient motor to revolve rapidly between the two blades or spring levers
C and Z, which are connected respectively to the + and - poles of the battery
or other source of electricity X, whilst K is connected to earth. The velocity with
which K. revolves may be varied, but for convenience of explanation I will suppose
it to make 20 revolutions per second. During 1/40th of a second the cam K will
push aside the lever C, putting the + pole to earth, and will allow Z to rest on the
contact B³, so putting the pole in communication with the contact P¹ of the key
B. During the next 1/10th of a second the pole will through Z be put to earth,
while the pole will communicate through C and A³ with P, the contact of the
key A, and so on alternately. In the receiving instrument there is a polarised relay
having two armatures, the one A' actuated by + currents and the other B¹ by
currents. To this might be substituted two polarised relays, with one armature.
If only the A key be worked the line will convey + currents, succeeding each
other every 1/40 of a second, the armature B¹ in that case resting against its upper
contact, and so closing without resistance the circuit of the local battery Y¹, which
under those conditions does not affect the coil of B². Meanwhile the armature A¹
being attracted by the action of the successive + currents, will by its lower contact
at each vibration bring the coil A2 into action, and these vibrations succeed each
other so rapidly that the effect on A² will be practically equivalent to that of a
constant current. In like manner if the key B be worked alone, the coil B2 will be
affected. If both keys A and B be worked the line will convey a series of alter-
nating + and
impulses, those of each sign affecting only its own receiver.
Instead of employing the transmission of impulses to work the receiving instru-
ment their cessation may be employed in the manner shewn diagrammatically by
Figure 2. In this case the blades C, Z, respectively make connection to the resting
contacts R, R', of the keys A and B, so that while these keys are not worked the
line transmits a succession of alternating impulses, causing the armatures A¹ and B'
to oscillate. But with sufficient speed of reversal and suitable regulation of the
relays, the effect of this can be made practically the same as if the armatures rested
midway between their contacts without influencing A² or B2. If however either or
both of the keys A, B, be worked so as to interrupt the succession of transmitted
impulses, then either or both the armatures A or B₁ rest against their upper con-
tacts, completing circuits for their respective coils A², B².
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The arrangements so far described effect double transmission, but only in the one
direction.
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Figure 3 shews diagrammatically an arrangement whereby each of two
stations 0, U, connected by a single line wire can receive or transmit by
either or both of two sets of apparatus without interference. Station Ohas
the cam arrangement, as in Figure 2, and the coils of the relays Q, Q¹, are so con-
nected by the line that the armatures A¹ and A* are caused to oscillate by + im-
pulses sent from O to U, whilst B' and B are caused to oscillate by impulses
sent from O to U. At U each of the two keys consists of two metallic pieces M, N,
in the one, and M', N¹, in the other, insulated from each other.
When there is no manipulation at O alternate + and impulses are transmitted
by the line to U, and pass there through the coil of Q1, the lever L, contact T, lever L',
and contact T¹ to earth, the armatures A¹, A, B', B*, oscillating without effect on
their receivers.
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Should the key A alone be worked, causing the + impulses to cease, the arma-
tures A, A, rest on their upper contacts, and the receivers A2, A3, are actuated ;
and in like manner if B alone were worked, B2 and B are actuated. If both A
and B be worked at the same time, no impulse being transmitted to and by the
line, all the armatures A¹, A4, B1, B4, rest against their upper contacts, and all the
receivers act. If the key A3 at U be worked for transmission to O, its part M raises
the lever L, and its part N raises the lever R. The current of the battery X¹ passes
by N and R, I¹ and R¹ to a rheostat R, h, and thence to earth, while the + current
of X passing by M and L to the line, meets the alternating currents thereof.
The
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currents from O add to the tension of the + current from U, but the

page_text: rheostat R, h, which is introduced in the circuit is so adjusted as to reduce the
intensity of the resulting current to that of the one battery, and thus the currents
from O continue to act as before, the armatures B¹, B, continuing to oscillate. But
the currents from O being neutralised by those from U, the armatures A¹, A',
cease to oscillate, and the receivers A2, A5, are actuated.
If the key B³ be worked alone its part M raises the lever L³, and N' raises R'.
The current of X¹ passing through M, N₁, and R¹ goes to earth through the
rheostat R, h, while the current from X' passes by M¹, L', T, and L. to line,
meeting the alternating current thereof, and neutralising the currents from O, so
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that B and B are actuated.
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If the two keys at U act at one time the + pole of X' is connected to line by M
and L, but the pole of X being connected to M¹ and L' is insulated from T¹, and
also being connected to N and R is insulated from i¹. There is thus a breach of
circuit, so that the line transmits no impulses, and consequently all the receivers
act.
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If the key A at O be worked at the same time as B³ at U, the former suppresses
the currents from O, the latter sends to line currents which neutralise those
sent from O, consequently the relays Q and Q¹ are not influenced by any currents;
the armatures all rest and actuate all the receivers, and a like result follows when B
at O transmits at the same time as A³ at U. By combining the system of double
transmission, above described; with a known system for duplex telegraphing, the
result is a quadruplex transmission.
The two systems may be variously combined, the relays, for example, may be
arranged as a Wheatstone bridge, or provided with differential coils.
The means of distributing the impulses may be placed between the line battery
and the keys, as above described, or between the keys and the line, according to an
arrangement for double transmission, according to my system, shewn diagramatically
at Figure 4. Here the key A is connected to the C blade, and B to the Z blade, the
cam K being connected to line. When not worked A puts C in connection with
the pole of X, and B puts Z in connection with the pole of X¹, so that the
cam in revolving causes a succession of alternating impulses to be sent into line,
producing effects such as have been already described.
Either key when it is worked puts its battery to earth, and so suppresses the
impulses of the one sign. In a similar manner the connections may be arranged so
that the working of either key, instead of causing cessation, causes transmission of
the impulses of the one sign.
From what has preceded it will be seen that double transmission is effected by
causing vibration of two armatures under the influence of two currents of opposite
sign. A like effect can be produced by the influence of currents of one sign inter-
rupted or varied in intensity, as I will now describe, referring to Figure 5.
The armatures may be either polarised or not; I will suppose that they are not
polarised, but that armature A' is so adjusted as to be attracted under the influence
of currents having intensities 1 and 2, and armature B₁ to be attracted under
influence of currents having intensity 2, but not when the intensity is 1. The line
is connected to the cam K and to the keys A and B. When neither key is worked
the cam meeting P puts line in communication with one pole of the battery, and
meeting R puts line to earth through a rheostat R, h. There will thus be trans-
mitted to line a succession of intermittent impulses of high intensity, say 2. The
two armatures will be attracted at each impulse, and therefore will rapidly oscillate
without effecting their respective receivers.
If the key A alone is worked the line is directly connected by it to the battery.
As the cam meets P the line receives a current of intensity 2, but while it bears on
R, the line being also put to earth through the properly regulated rheostat R, h,
receives a current of intensity 1, so that there is thus a succession of currents of the
alternating intensities 2 and 1, those of the one intensity causing the armature B¹ to
be attracted, but the other not; consequently this armature continues to oscillate

page_text: without actuating its receiver. Meanwhile A¹ being attracted when the intensity
is either 1 or 2 actuates its receiver.
If the key B be worked alone the line is put to earth through the rheostat R, h.
When the cam meets P the line receives the weakened current of intensity 1, and
when it meets R the line receives no current. There is thus a succession of inter-
mittent impulses of intensity 1, causing the armature A¹ to oscillate without
actuating its receiver, whilst B¹, not being attracted at all, continues to actuate its
receiver.
When both keys are worked together, putting the line in connection with the
battery, and also through the rheostat to earth, there is a continued current of
intensity 1, and thus the armature A¹ being attracted actuates its receiver, and the
armature B¹ not being attracted also actuates its receiver.
As relay I prefer the arrangement of polarised electro-magnet, shewn in front
view at Figure 6, in plan at Figure 7, and in side view at Figure 8. On the N pole
of the magnet are set two soft iron cores a, a', and on the S pole are mounted the
two soft iron armatures c, c¹, each of which oscillates between contacts i and j, the
one acting under the influence of a + current, or a current of greater intensity, the
other under that of a current, or one of lower intensity. When either touches
the lower contact it closes the local circuit, so transmitting the signal to the
receiver.
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Having thus described the nature of the said Invention and in what manner
the same is to be performed, I claim,-
First. Effecting double telegraphic transmission by means of a rapid succession of
alternating electric impulses of different sign or intensity, those of each kind being
directed by one of two operating keys, substantially as herein described.
Second. Combining the means for double transmission above referred to with
known means for duplex telegraphy, thereby effecting quadruplex transmission.
In witness whereof, I, the said Jules Xavier Eugène Sieur, have hereunto
set my hand and seal, this First day of May, in the year of our Lord One
thousand eight hundred and seventy-eight.
Witness,
CH. ARMENGAUD, JR.,
Civil Engineer,
23, Boulevard de Strasbourg.
J. X. E. SIEUR. (L.S.)