IMPROVE- MENTS IN ELECTRIC TELEGRAPH APPARATUS
Year: 1879

page_text: LETTERS PATENT to Charles Denton Abel, of No. 28, Southampton Buildings,
Chancery Lane, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN ELECTRIC TELEGRAPH APPARATUS.” A communication from abroad
by Ernst George, of Berlin, in the German Empire.
Sealed the 4th May 1880, and dated the 10th November 1879.
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel at the
Office of the Commissioners of Patents on the 10th November 1879.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex. "IMPROVEMENTS IN ELECTRIC TELEGRAPH APPARATUS."
[A communication from abroad by Ernst George, of Berlin, in the German
Empire.]
This Invention relates to an improved construction of electric telegraph
apparatus wherein a dial or step by step instrument is combined with a type
printing apparatus.
In the instrument of this nature invented by Dr. P. Dujardin a type wheel was
attached to the crank spindle of a dial or step by step sending instrument; on
depressing the crank handle a corresponding type was pressed upon a paper strip,
and this was moved forward a step by means of a pair of feed rollers actuated by a
lever receiving its motion from a rod passing through the hollow axis of and con-
nected to the crank handle. With this apparatus the message could also be printed
at the receiving station if the operator followed the motion of the pointer of the
dial with the crank handle, pressing the latter down at the divisions corresponding
to those where the pointer stopped. This operation was, however, very inconvenient
on account of the pointer and the crank handle being situated on two separate dials.
The construction of apparatus to which the present Invention relates obviates this
inconvenience, and at the same time has the advantage that the driving or clock-
work mechanism that moves the pointer is wound up automatically, and that
the apparatus is of simpler and cheaper construction.
For this purpose there is provided below the alphabet dial a toothed ring, each
of the teeth of which projects over a letter thereof. This ring, which is supported
on rollers, is slightly turned on its centre if the crank handle is depressed as one of

page_text: the divisions owing to an incline on the crank pushing against the corresponding
tooth of the ring. This motion is utilised for effecting the impressing of the cor-
responding type and also for moving the paper strip forward. On lifting the crank
the toothed ring is moved back to its original position by the action of a spring.
The motion of the toothed ring might be effected by an electro magnet, by causing
the depression of the crank to close a local electric circuit. The pointer which is
actuated from the distant station can have its axis passing through the hollow axis
of the crank, and the driving mechanism of the receiving instrument, which is
thus combined with the sending instrument, can by this means be automatically
wound up.
If the commutator on the crank spindle is put in gear at both stations, the
operations at the receiving station can be controlled from the sending station; in
this case however two line wires must be used, or the apparatus must be arranged
for duplex telegraphy.
The type wheel can however be arrested by the pointer itself, by agency of an
electro-magnet, by applying to the type wheel a contact arrangement which closes
or opens a local circuit whenever it is touched by the pointer. The apparatus for
this purpose might be advantageously arranged as follows:-The type wheels at
both stations receive approximately synchronous motion by clock-work mechanism,
which in addition actuates a commutator of which, however, that of the receiving
instrument is out of gear.
To the spindle of the type wheel is connected the one end of a coiled spring, the
other end of which is attached to a spindle forming a continuation of the first
named one, but without being fixed thereto.
This spindle carries a pointer and an escapement wheel having as many teeth as
the commutator; an electro magnet permits the step by step motion of this spindle
as long as it is actuated by currents sent by the commutator of the sending instru-
ment. If the driving mechanisms of both stations have synchronous motion the
pointer must always stand on the same point of the type wheel, and the spiral
spring will have the same tension. By this means the sychronism can be readily
regulated either by the operator, or automatically by the pointer, by causing at the
same time an electro-magnet acting as a break to be put in action.
If the driving mechanism at the sending station be arrested at a particular letter
by the depression of a key the currents are intercepted and the pointer of the
receiving apparatus stands still; its driving mechanism, however, moves a little
longer, namely, until the before mentioned contact point of the type wheel comes
in contact with the pointer. By this means an electro magnet is put in action
which stops the driving mechanism, whereupon the printing apparatus is brought
into action. As soon as the driving mechanism of the sending station is released
again the currents are again sent, the pointer turns, and its contact with the type
wheel is intercepted, and consequently the driving mechanism of the receiving
instrument is also liberated again. The advantage of this type printing instrument
consists principally in that the mechanism, the step by step motion of which is
controlled from the distant station, has very little momentum, so that rapid
telegraphing is possible. The clockwork of the sending station can however be
stopped and released automatically instead of by the sending keys. For this purpose
the telegram could be perforated in a paper strip, and this could be caused to close
a local circuit through its perforations in such manner that an electro-magnet
included therein only comes into operation so as to stop the clock work when the
letter is to be printed.
By this method of automatic sending all line currents are sent by the commutator,
which gives reliable contacts, while the perforations of the paper strip only effect
the closing of the local circuit. The perforation is also very simple, as it can be
effected by means of a key instrument similar to the ordinary dial telegraph
manipulator.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Denton Abel in the Great Seal Patent Office on the 8th
May 1880.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex. "IMPROVEMENTS IN ELECTRIC TELEGRAPH APPARATUS."
A communication from abroad by Ernst George, of Berlin, in the German
Empire.
'
This Invention relates to an improved construction of electric telegraph
appparatus wherein a dial or step by step instrument is combined with a type
printing apparatus.
In the instrument of this nature invented by Dr. P. Dujardin a type wheel was
attached to the crank spindle of a dial or step by step sending instrument; on
depressing the crank handle a corresponding type was pressed upon a paper strip,
and this was moved forward a step by means of a pair of feed rollers actuated by a
lever receiving its motion from a rod passing through the hollow axis of and con-
nected to the crank handle. With this apparatus the message could also be printed
at the receiving station if the operator followed the motion of the pointer of the
dial with the crank handle, pressing the latter down at the divisions corresponding
to those where the pointer stopped. This operation was however very inconvenient
on account of the pointer and the crank handle being situated on two separate
dials.
In the improved construction of such apparatus, now to be described, this incon-
venience is obviated by arranging the type printing mechanism directly in
combination with the receiving instrument, which arrangement also gives the
following advantages:-It admits of a quicker transmission of messages, the whole
arrangement can be made simpler, more compendious, and cheaper, the driving
spring which tends to rotate the index spindle can be automatically wound up
again by the manipulator, and, lastly, the type printing mechanism can when
applied to the receiver be automatically actuated by the latter.
I will first describe a suitable construction of a simple apparatus, in which the
type wheel is turned by the operator at the receiving station by means of a crank
handle in accordance with the index.
Fig. 1 shews a plan of the apparatus; Fig. 2 shows an underside plan of the
manipulator with the printing mechanism; Fig. 3 shews a plan of the receiver
with alarum; Fig. 4 shews a vertical section of the entire apparatus, manipulator,
with receiver.
Figs. 5 to 15 shew diagrams and details.
The printing manipulator shewn in Fig. 2 in constructed as follows:—
The hollow crank spindle a which runs in the plate b carrying the letter disc
and in the arm c carries a circuit closer d with its contact lever d¹ and pawl d",
a type wheel e, and an oval disc f. The crank handle 9 is fixed by
two screws h to the end of the spindle a projecting above the latter dial,
so that the spindle is rotated by turning the crank handle. On depressing the
handle it turns upon the screws h. The depression can bowever only be effected
accurately in the middle of each division, because the pin i attached thereto can
only then enter the notches in the plate 61; an incline on the block j of the handle
then acts on a corresponding tooth of the toothed ring k running on rollers l, and
pushes this somewhat to one side. By this motion the spring pawl m fixed to the
toothed ring is caused to move the ratchet wheel of a pair of rollers n that feed
the paper strip forward by one tooth, while the screw o also fixed to the toothed
ring shortly afterwards presses the printing lever p against the type wheel. The
printing may be effected by means of a coloured strip, which is led together
with the white strip between the type wheel and printing lever. In order to

page_text: enable a fresh strip to be introduced at any time without removing the plate b,
an endless band may be passed through the apparatus to which the paper strips
can be attached. On raising the handle the spring 9 draws the toothed ring k
back against the stop q¹, and the printing lever p is at the same time brought back
into its original position again by a spring. The tooth p¹ of the lever has for its
object to move the type wheel e half a division forwards or backwards when it
is desired to pass from letters to numerals or punctuations, the 56 symbals engraved
on the type wheel being so arranged that letters alternate with numerals or
punctuations. In this case, namely, the crank handle is pressed down in such a
position that one of the blocks with inclined face fixed on the type wheel comes
within the range of the tooth p¹, by which means the shifting motion is effected.
The type wheel is loose on the shaft a, and can turn on the same to the extent of
one half of a letter division, the extent of such motion being limited by a slot 8,
into which passes a stud 8¹, on the circuit closer, while a spring 811 holds the type
wheel stationary in both positions; t are standards that connect the entire
apparatus with the receiver, which is shewn in Fig. 3. The escapement spindle U
carrying the index passes through the hollow spindle a, as shewn at Fig. 4. The
driving spring has its one end fixed to its drum or casing, and its other end to the
spindle v, carrying a ratchet wheel v₁, which is moved forward one tooth every
time the lever w having the pawl w' moves to and fro through a certain angle
on the spindle v. By this means the spring is wound up; the to and fro motion of
the lever wis effected by the rotation of the oval disc f against the action of the
spring x. When the driving spring is wound up to a certain tension the spring
cannot draw the lever w back, and the further rotation of the crank has then no
remontoir action. The electro magnet armature y effects by means of the usual
Breguet escapement the step by step rotation of the index spindle u.
The set
screw y¹ serves to regulate the spring for breaking contact. The last wheel but
one of the driving gear has pins, which on its rotation actuate the striker z of a
bell z, the striker being moved out of gear with the pins by a slide 2", when it is
desired to stop the alarum. In order to wind up the spring without rotating the
crank handle, the lever w may be provided with a projecting arm wll, so that it can
be actuated by hand for rotating the ratchet wheel v¹. It is well understood that
with a receiver actuated by clockwork driving mechanism, this may be so arranged
that the index moves at once to the required starting point on moving a lever
extending beyond the instrument; in Fig. 17 such an arrangement is shown. This
lever can in that case be used also for stopping the escapement spindle at will; it
may in that case be advantageously so arranged that it remains stationary in each
of its two positions. Of course the receiver could be actuated without clockwork
mechanism, directly by the lever of the electro magnet in a well known manner.
By means of the contacts produced by turning the crank handle, the index of the
instrument at the sending station can be rotated, and thus each letter be controlled.
In arranging the apparatus for this purpose it will have to be considered whether.
the crank handle is to be rotated while the index is moving, or only when this has
completed its motion. In the first case two line wires must be employed, or the
apparatus must be arranged for duplex telegraphy. Fig. 5 shews the arrangement
of two apparatus for working with two line wires, and by breaking circuit of a
continuous current; a is the contact arrangement of the commutator; b is the electro
magnet; c, the battery; and d the earth plate; the arrangement is otherwise well
understood. The letters a, b, c, and d, indicate generally the above named parts in
all the arrangements to be described. Fig. 6 shews an arrangement of two
apparatus working with two line wires, and with closing circuit of an interrupted
current. If several stations are to be included in one circuit, the electromagnet b
will have to be put in the circuit of wire 1, and the contact mechanism a in the
circuit of wire 2, see also Figs. 7 and 8, which shew respectively arrangements for
working by breaking circuit of a continuous current, and by closing circuit of an
interrupted current. The calling station must by means of a shunt put the
electro-magnet b in the circuit of line wire 2, and the contact apparatus a in the

page_text: circuit of line wire 1, whereupon the signalling can commence.
With the arrange-
ment for working by breaking circuit, as at Fig. 7, care must be taken that during
the shunting operation the circuit is not broken. Fig. 9 shews a shunt which fulfills
this requirement. On the shaft o of insulating material, and provided with a
crank handle p, bear eight springs connected with the line wires and apparatus.
The pins on the shaft are electrically connected together by means of wires in the
manner shewn. The four pins q prevent the interruption of the circuit during the
shunting. If the intermediate stations are to be able at will to signal to the right
or to the left, they must have a second shunt r. It will be well understood that
the intermediate stations can have two signalling instruments.
The
I will now describe the arrangements for duplex telegraphy. Fig. 10 shews the
arrangement for any number of stations, the batteries c¹, and V, are only required
at the end stations; they should be as equal as possible in strength and have
poles of the same names on the line, so that ordinarily there is no current.
contacts of the commutator by its rotation alternately open the circuit between the
two points at 8 and connect on the other hand the three points at t. If this be done for
instance at the station III. the currents of both batteries go to earth at this station,
and will pass through the double coils of the electro magnets 6шI in contrary
directions. In this condition 6III is not in action because both currents are of equal
strength. This is effected by means of resistances uIII and III. On the other hand
the electro magnets of the other stations will operate because the opposite action of
the currents does not occur. If now at the station called for instance station II.,
the crank handle of the printing instrument be moved in accordance with the
index, and thus the contact apparatus be put in action, only two other new contact
positions can occur; 1st., t II. and III. closed and a II. and t III. broken, or 2d,
t II. and t III. closed and s II. and 8 III. broken. In the first case b III. must
signal but not b II. in the last 6 III. and b II. together. It is easily shewn by the
laws that this really takes place. If the lesser of the two resistances u and v (u II.
and vII.) are put in the circuit between t and d, then in place of the greater
resistance (vII. and u III.) the difference between u and v (v II.—u II. and u III.—
v III.) must be introduced. The telegram can only be read at the two corresponding
stations because the currents are rendered quite confused by the duplex systein,
while it is only at the end stations that they are disentangled again. In circular
signalling the contacts of the commutator must be made inoperative before turning
the crank handle. For the arrangement at Fig. 10 the contact apparatus shewn
at Fig. 11 would be suitable. The pawls a and b, Fig. 11, have fixed on them insulated
pieces of metal c and d, to which are attached the springs e and f; the metallic
connecting plates g and h of the springs e and fare fixed in an insulated manner
to the base plate, and are connected to the wires 1 and 2. The lever k of
non-conducting material turns on the screw i and carries a metal piece / provided
with a contact screw, this is put in electrical connection with the wire 3 by means
of the spring m; the spring n on the other hand which presses the lever against
the pawls is in electrical connection with the wire 4. The metal piece terminating
in the spring n has at o a contact point; a spring p fixed to the metal piece c has its
contact point perforated in order that a platinum pin q screwed into the pawl a
can pass through. The platinum pin r is fixed to the metal piece d. The wire 5
is attached to any convenient point of the metal parts of the apparatus. On the
rotation of the commutator s therefore alternately 3 will be connected with 1 and
5, and 4 and 2 be interrupted.
The contact arrangement can be made somewhat simpler if the apparatus be
connected as at Fig. 12. In that case however the electro magnets will not always
be equally excited, because the current sometimes passes through the whole of the
coils and at other times only through half the coils, which would result in uncertain
working.
If the crank handle is only turned when the index has completed its motion a
single line wire is sufficient, even without arrangements for duplex signalling. In
that case however the commutator must send double the number of currents in order

page_text: that the crank handle may be always stopped at a closing or at an opening of
circuit; furthermore the receiver must be thrown out of gear during the sending of
currents of its own commutator. In order to effect this last the clockwork can be
automatically stopped by means of the toothed ring k (Fig. 2) as long as the crank
handle is not depressed. On rotating it its own index will then remain stationary,
even though the electro-magnet be put in action; on depressing the handle on the
other hand the clockwork is released and the index can be put in motion from the
distant station. The throwing out of gear of the receiver during the sending of
the currents of its own commutator can also be effected by suitable contact making.
Figs. 13 and 14 shew such an arrangement for working respectively by breaking
continuous circuit and by closing an interrupted circuit. In the first arrangement,
Fig. 13, it is assumed that the contact apparatus a breaks the circuit only after the
second contact has already been established, in order that the armature may not
break contact during the turning of its own crank handle; by the aid of a contact
arrangement, such as at Fig. 11, this may easily be accomplished. The throwing
out of gear of the receiver may however also be effected by means of a contact x,
which is made in raising the crank handle of the manipulator; this contact would
best be effected by means of the toothed ring k, Fig. 2.
a
The arrangement first described by F. D. Botto, wherein the same poles of the
line batteries at the end stations are put to the line, can be used for the before
described apparatus, as shewn at Fig. 15; y and z are the resistances by means of
which an equal strength of current is maintained. If this be not required they
may be dispensed with.
The type wheel can, as first above mentioned, be entirely automatically stopped
by the stopping of the index. I will proceed to describe such an automatically
working type printing apparatus in combination with the step by step receiving
instrument. Fig. 16 shews a plan of the apparatus with the top plate removed;
Fig. 17 shews a vertical section; and Figs. 18 and 19 shew details. The armature
a of the polarised electromagnet a¹ (or an ordinary electromagnet may be used)
acts on a lever b, Fig. 17, having a fork c which, on the oscillation of the lever b,
effects the step by step motion of the escapement wheel e on the spindle d, which
also carries the index f and an arm_g. The clockwork imparts motion to the type
wheel h, and this motion is transmitted by the crown wheel i to the wheel k, this
being rotated in the same direction in which the lever b turns the escapement
wheel e. This wheel k, which is rotated with the same speed as the type wheel,
carries a contact lever m (Figs. 17 and 18) on the bracket 7, which lever has a
roller that can strike against the arm g. When this takes place the lever mis
raised from the insulated contact screw o on the wheel k, which screw is connected
by a wire with the contact ring o¹ on which rests the contact spring o" fixed to
but insulated from the cover plate. On breaking the contact at o a local circuit is
interrupted, in which is an electromagnet p, the armature p¹ of which in moving
out of contact stops the clockwork by means of the notched disc q¹ on the flyer
spindle q. By this means a contact is made at r which closes the local current
through the electromagnets 8, the armature 8¹ of which, by its motion, effects
movement and impression of the paper strip in the well known manner. Ordinarily
therefore when the index spindle d is stationary the clockwork is stopped by
movement of the armature away from its electromagnet p. If however currents
are sent from the distant station, the fork c is put in motion and effects the
rotation of the spindle d, the arm g moves away from the roller n, the lever mis
put by the spring m³ in contact with the contact screw o, the local current is closed
through the electro magnets p, the armature of which is attracted, and the clock-
work is thus put in motion, so that the roller n can follow the arm g. If this is
stopped at a certain letter from the distant station the roller n comes in contact
with it again, the contact o is interrupted, the clockwork is stopped, and
the impression is effected. This action is repeated until the message is completed.
The movement of the wheel k is also transmitted by means of a pair of wheels on
the spindle t to the wheel u which has a cap with opening at top. Through this

page_text: opening the index f may be seen, so that the synchronism between the index and
the type wheel may be readily observed and be suitably regulated by means of the
adjusting screw w which presses a break spring w¹ against a dise on the spindle g.
The synchronism need however not be perfect; if the clockwork goes somewhat
slower than the index spindle the type wheel will nevertheless be stopped at the
right point if only the index does not stop for too short a time; if however it
moves too fast, the armature p¹ of the electro magnet p will, from time to time,
effect a momentary breaking or stopping of the clockwork, but the impression is
only effected at the stopping of the index when the clockwork is stopped for a
somewhat longer period. To the spindle d is fixed one end of a spiral spring, the
other end of which is attached to the cap v; the power required for rotating the
index need therefore not be derived solely from the electromagnet. This spring will of
course require to be maintained always at about the same tension. The apparatus can
at any time be put to zero. For this purpose the lever b is arranged so as to be capable
also of some vertical motion on centres; by means of a handle the fork c can be
raised out of the teeth of the escapement wheel e, and the knife edge b¹ be put in
gear with the pin e' corresponding to the zero position. The escapement wheel
then springs at once to zero just as with the Breguet receiver. The same apparatus
serves also as manipulator. For this purpose the spindle x carries also a com-
mutator y and a pin drum z, shewn broken off in Fig. 16. Above this are the keys
by means of which the pin drum and consequently the clockwork can be arrested
at a point corresponding to any desired letter. Ordinarily the contact arrangement
of the commutator is put out of action by a switch, but if a message is to be sent
the contact arrangement at the sending station is put in gear and the zero key is
pressed down. The lever a of the electro magnet a' is then moved a few times to
and fro so as to remove the arm g from the roller n. The contact is thus estab-
lished at a, whereupon the armature p¹ of the electromagnet p releases, the
clock work, which is then only stopped by the depressed zero key. If this be
released the clockwork is put uninterruptedly in motion, the roller n not being able
to touch the arm g because the currents transmitted by the commutator of the
sending station also pass through the line electromagnet of that station and put
the index spindle in motion. The arrangement may also be such that the com-
mutator of the apparatus at the receiving station acts upon the line electromagnet
of the sending station. For this purpose the arrangements at Figs. 5, 6, 7, 8, 10,
and 12 can be used. The arm g therefore is always at the same distance from
from the roller n during the sending of the message.
The message is now transmitted in the usual way by the depression of the
corresponding keys. If the receiving station requires to interrupt the sending
station it is only necessary to interrupt the line wire; the electromagnet lever of
the sending station then stops, and with it the arm g, the roller n touches the latter,
and the electromagnet lever p¹ stops the clockwork.
In sending a telegram the stopping of the clockwork required for transmitting a
letter can also be effected by the lever p¹ instead of mechanically stopping it by the
depression of a key on the pin drum z. For this purpose the pin drum z should be
so connected to the spindle x that a contact is made as soon as it is endeavoured
to stop the pin drum, and this contact can then put the electromagnet p in action.
Lastly, an arrangement may be mentioned which might be employed in order
that the local current may only be momentarily interrupted. The wheel k, Fig. 18,
has for this purpose a second insulated contact screw o¹ll; the arrangement of this
is shewn at Fig 19. a is the local battery. PI. and P II. are electromagnets between
the poles of which plays the armature p' that stops the clockwork. This remains
in either of the two positions when no current is passing through the electro-
magnets; the armature p¹ then alternately breaks the connection with PI. and P II.
at the contact screws 1 and 2. From the contact screw the wire passes to the
printing electromagnet 8, whose armature s¹ in signalling acts upon a lever 8 II.
which also remains in each position; this interrupts in the one position the circuit
at the contact screw 3, and it only makes this contact again when the clockwork

page_text: resumes its motion, when p¹ touches PII. again. The action of the electromagnet
lever during the signalling will be readily understood from this.
Having thus described the nature of the said Invention and in what manner
the same is to be performed, as communicated to me by my foreign correspondent,
I claim,—
First. The construction of type printing apparatus for dial electric telegraph
receiving instruments, wherein a type wheel actuated by a crank handle is moved
in accordance with the index actuated from the distant station and situated on the
same letter dial as the said crank handle, the impression of the corresponding types
being effected by the lateral motion or shifting of a ring or wheel shaped part,
when the crank handle is made to mark the divisions at which the index stops,
substantially as herein described.
Second. The construction of type printing apparatus for dial electric telegraph
receiving instruments wherein a type wheel, which is rotated in accordance with
the index actuated from the distant station, is automatically stopped at the required
point by the said index by causing a contact device in connection with the type
wheel to touch either the index or a separate arm or pin on the index spindle
when this stops, whereby electromagnets are put in action that effect the stopping
of the type wheel and the impression of the corresponding type, substantially as
herein described.
Third. In combination with the apparatus referred to in the first above
claim, the arrangements herein described and shewn in Figs. 5, 6, 7, 8, 10, 12,
13, 14, and 15 of the Drawings for the purpose of repeating or controlling the
transmitted message.
Fourth. In combination with the apparatus referred to in the second above
claim, the arrangements herein described and shewn in Figs. 5, 6, 7, 8, 10, and
12 of the Drawings for the purpose of repeating or controlling the transmitted
message.
In witness whereof, I, the said Charles Denton Abel, have hereunto set my
hand and seal, this Seventh day of May, in the year of our Lord One
thousand eight hundred and eighty.