IMPROVEMENTS IN TELEGRAPHIC APPARATUS
Year: 1873

page_text: LETTERS PATENT to Robert Coddington, of No. 3, Bedford Place,
Russell Square, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN TELEGRAPHIC APPARATUS." -A communication from
abroad by Merritt Gally, of Rochester, New York, United States of
America.
Sealed the 2nd September 1873, and dated the 17th April 1873.
PROVISIONAL SPECIFICATION left by the said Robert Coddington, at
the Office of the Commissioners of Patents, with his Petition, on
the 17th April 1873.
FI, ROBERT CODDINGTON, of No. 3, Bedford Place, Russell Square, in
the County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN TELEGRAPHIC APPARATUS," (a communi-
cation to me from abroad by Merritt Gally, of Rochester, New York,
United States of America,) to be as follows:-

page_text: GENERAL DESCRIPTION.
I am aware that pendulums having simply a vibratory movement
have been used in connection with telegraphic instruments with an
attempt to secure unison thereby, but they have been comparatively
inoperative especially where very rapid pulsations have been required.
In their results they have been deficient for many reasons, prominent
among which are the facts that their vibrations have been comparatively
slow, and their speed different in different portions of their arc of vibra-
tion. The latter of these defects I partially overcame by constructing
upon the are a number of conducting faces varying in distance from
cach other in proportion to the variation of movement, and when
necessary varying also in breadth of face, but the results not being
fully satisfactory I brought into use the revolving pendulum. The
movement of such a pendulum remains equal in speed at all points
in the circle of its motion. On such a circle a great number of con
ducting faces may be placed; and as the pendulum can be revolved very
rapidly great accuracy can be attained in producing rapid timed
|´impulses.

page_text: I use the revolving pendulum in connection with a conducting pile of
peculiar construction, although it may be used with good results with
other kinds of repeating conductors. This pile is placed under the
revolving pendulum, and is made up of a number of rings or plates,
each having a conducting bar. The rings 'mentioned are first piled t
with intervening non-conducting substance, and then covered with a
ring or plate made up of a number of conducting and non-conducting
sections.
Within the pile is a solid ring. This ring may have an entire con-
ducting face, but to avoid any possibility of mixing impulses it is :
divided into as many conducting and non-conducting faces and intervals
as the upper plate of the pile.
Connected with the conducting pile described is another pile of con-
ducting plates of equal number. With this pile the operating keys make
the circuit connections; therefore the plates must equal in number the
characters of the type wheel, and these plates inust connect with as
many rings of the first described pile, and as many conducting bars
must cach connect with one of the conducting sections of the upper
plate of the conducting pile. There may be a greater number of the
conducting sections as will be herein-after explained for the purpose of,
adjustment.
Upon the shaft which revolves with the pendulum is a metalic
circuit connector. The gear of said shaft connects with the shaft of the
type wheel, and by means of such device two or more instruments may
be kept in unison without the use of an escapement; for example, let a
number of telegraphic instruments having the revolving pendulums
attached be connected to a telegraphic line; let a key representing a
particular letter of the alphabet be agreed upon by which the several
machines are to be tested as to unison. Now, as we have said. previously,
the key will close the circuit with the instrument for this letter by con-
necting the circuit wire with one of the plates of the external. pile. As
there is also another division of the circuit between the circular con-
ducting pile and the internal solid ring, this division will be connected
when the revolving circuit closer connects a conducting face of the
internal ring with a conducting face of the circular pile, corresponding
with the plate of the-pile which has been made to connect with the
circuit wire by the working of the key. The internal ring of the
circular pile is attached to or has a connection with the circuit wire.

page_text: .
The other part of the circuit wire connects with the pivot of the con-
nector operated by the key. The ends of both parts of the wire
mentioned forming a connection with the main line completes the
circuit. Now, if the pendulum of the several instruments be set in
motion, and the standard key of each instrument be depressed, if only
a single impulse passes the circuit at each revolution of the pendulum
the several instruments will be in unison, but if no impulse passes or a
number at each revolution of the pendulum the instruments will not be
in unison.
To adjust the instruments to unison the circular pile is made to turn
upon its axis by means of the handle working in connection therewith.
This will affect only the position of the conducting faces of the circular
pile in respect to the revolving circuit connector without affecting the
relation of the plates of the external pile and the conducting surface of
the circular pile, because the rings of the circular pile form at their
circumference a continuous unchangeable connection with the corrc-
sponding plates of the external pile.
To increase the speed of operation I use single keys representing a
number of separate letters of the type wheel which may be printed
during a single revolution of the type wheel by a single stroke of the
key. The key may indicate a number of characters representing a letter
or combination of letters if representative characters are employed.
This is accomplished by making the key circuit connector of such keys
form a connection with a number of the plates of the external pile or
a number of conducting faces of the circuit closer corresponding with
the characters to be given by sound or priut.
When the characters are to be printed with an ordinary type wheel in
order to secure the desired result with a single revolution of the wheel,
and to secure a large number of such keys representing many frequently
recurring words, sylables, and combinations, I first arrange the letters
of the type wheel out of an alphabetic order and in such a way as to be
able to spell as many words, sylables, and combinations with the letters
while passing in one direction around the type wheel.
✔
1. V
In order to further facilitate the manipulation of the keys I place
them in classified groups. The key movement is in most respects
similar to that described in my Patent of Great Brittain, No. 2481,
Aug. 21st, 1872. I will therefore state only the manner of connecting

page_text: it with the instruments herein described. The key circuit closer is made
to connect with its number of conducting points by the movement of
the key which acts in connection therewith.
The electric impulses which cause the printing of the characters act
upon the impression apparatus by means of an electro-magnet which.
brings type and paper into connection at the proper time to produce the
characters indicated by the stroke of the key or keys operated. The
type wheel is hung in reciprocating journal bearings when it is desirable
to make the contact of type and paper without an impression movement
of the paper holder, and as the printing impulses pass the circuit the
type wheel is brought into contact with the paper. In order to secure
sufficient time for the operator to depress a key and secure the proper
connections I make the returning shifter which returns the keys to
place in two parts, one part to act upon the keys which indicate the
numerals and the other part upon the keys which represent the letters.
As the letters and numerals are in separate groups on the face of the
type wheel the keys of the letters may be depressed during the time
in which the numerals are passing a given point, and the keys for the
numerals may be depressed while the letters are passing a given point.
A cam wheel revolves under a latch lever and lifts it relieving the
shifter and allowing the depression of the keys connecting with the
shifter while the lifting cam is passing under the lever latch.
lifting cam occupies that portion of the circumference of the cam wheel
which corresponds to the part of the face of the type wheel occupied by
the letters or numerals as the case may be.
.
The
The cam wheel revolves at equal speed with the type wheel. Thus it
will be seen that two cams will be necessary and also two lover latches
connecting with the shifters of their respective set of keys.
Having constructed the transmitting instruments so as to secure speed
and facility of operation, the next part of my Invention has reference
to increasing the transmitting capacity of the line.
Duplicate instruments have already been employed simultaneously
upon a single telegraphic line, but such a limited increase of capacity
does not answer the demand, and I have therefore constructed my instru-
ments with a view to the employment of more than two instruments
simultaneously upon a single line so that a number of messages may be
sent in either or both directions without conflict. For this purpose I

page_text: :
leave sufficient space. between. the letters of the-type wheels to allow a
number of impulses. to. pass through the magnet and depress the type
wheel during its movement, without making impressions upon the paper,
or I turn the shaft of the type wheel with a partial gear in such manner
as to allow a number of impulses to pass the line to act upon other
type wheels while the one under consideration is inoperative..
Eset the type wheels or gear of their shafts of several instruments of
the line in such a relative position in respect to their material for
printing as to secure to cach the printing: of the several wheels by
different impulses..
I set the circular pile of each. instrument to correspond with. the
relative position of its type wheel or gear and the number of instru-
ments are prepared for usc..
:
If each instrument is provided with its revolving pendulum, and
the several pendulums are revolving in unison it will be seen that all
the instruments may be simultaneously employed printing successively
by succeeding impulses, and that no impulses will be necessary to pass
the circuit except one for cach printed letter. If, however; it is desir-
able to do away with the use of so many revolving pendulums I remove
them from the instruments and employ but one, with connections on
the main line. It is not necessary that this should. be a strictly time
keeping instrument, but any rapid pulsator with a comparatively steady
*movement may be employed. I, however, use the revolving pendulum
as the best means of producing a regular and rapid pulsator. In order
to employ a number of instruments simultaneously with this arrange-
ment of devices I use the pulsator of the main line for controlling the
several instruments of the line by means of a succession of impulses
between which the printing impulses of the instruments are produced.
in their proper order. Although in such case the revolving pendulums
may be removed from the transmitting or receiving, instruments the
circular piles and circuit closers are retained together with the motor.
I set the relative printing positions of the type wheels or gear of the
several instruments as in the previous case. I make the conducting
faces of the pile connected with the revolving, pendulum of the main
line to differ from those of the piles of the instruments as to relativo
.position, making them to correspond with the non-conducting intervals
of the instrument piles. I make the pulsations of thic line pulsator to

page_text: :
preserve the proper order of printing or sounding of a a number of trans-
mitting or receiving instruments upon the line by means of escapements
or other appropriate devices which secure certain and accurate move-
ments by succeeding impulses. I set the pulsator of the main line in
motion and the wheels of the several instruments to be employed are
allowed to revolve but are kept in unison by the line pulsator.
Now as the impulses caused by working the keys of the transmittors
can occur only between the impulses from the pulsator of the line, it is
apparent that all the several instruments may be employed on a single
line without conflict when transmitting the same message. Now if the
type wheels or gear of each of the several instruments be set so that
their printing or sounding movements must occupy different portions of
the intervals between the pulsations of the line pulsator, it will be seen
that all may be opperated on different messages without conflict, each
transmitting its own message in either direction over the line. As a
single telegraphic wire can transmit as many distinct electric impulses
as can be employed by a large number of operators, it is evident that
with such an adjustment a large number of operators may be constantly
employed upon a single line without conflicting in their operations. In
order to read by the ear the message which is being printed, or one
message while another is being printed, or a sound message transmitted
by means of keys which represent entire letters or combinations of
letters, I attach to the instrument an additional conducting ring or
equivalent and divide the large conductors corresponding to the con-
ductors of printing device into dots and dashes representing the sound
alphabet. I make a connection between this sound conductor and a
common "sounder," and the message passing through the instrument
upon the interval to which the sound conductor or circuit closer is set
may be read by the ear.
The paper upon which the message is to be printed I place upon a
cylinder which turns with the type wheel at such times as the types are
in contact with the paper; the line of printing is thus formed around the
cylinder. When a line is completed the cylinder is suddenly moved the
space of a line. The next line of printing is immediately begun, and so
on until the face of the cylinder has been printed over.
In order that the printing may still go on uninterruptedly I use two
or more cylinders. The position of the cylinders is changed immediately
upon the completion of the printing upon one, so that the other comes

page_text: :
To keep
into printing position, and allows time for removing the printed page.
from the first, while the printing is going on upon the other.
the cylinders: constantly supplied with paper I make them hollow, and
upon the internal spindle I. place a roll of paper, the end of the paper
being passed through an opening in the side of the cylinder, and having
been passed around its circumference is clamped by a spring clamp. To
remove the printed paper it is only necessary to draw out the paper,
unwinding the roll, and tearing off the printed part. This leaves the
cylinder freshly covered..
By clamping both ends of a sheet which simply covers the cylinder
single sheets may be used instead of the roll.
The paper used either in rolls or sheets may have upon it the usual
printed headings, &c., but for printing the headings or frequently
recurring portions of the work I attach to the instrument a form wheel
which is placed upon a rocking bearing, and may be brought into
contact with the paper upon one of the cylinders. By working a lever
or other convenient device the form wheel and cylinder are brought into
contact, and ink having been applied to the wheel a single turn of the
wheel will print the form upon the paper of the cylinder. A number of
marking spurs or creasing wheels are also brought into contact with the
paper of the cylinder during its revolution which prepares it for easily
folding for delivery.
By examining the operating key movement of former Patent referred
to it will be seen that by combining such key movement with the
transmitting instruments herein described a number of keys representing
different letters may be struck simultaneously by a single stroke, and
without holding the keys the several letters will be transmitted in their
proper order, as the keys are brought back to place only after the proper
work has been accomplished by each. This enables. an operator to select
a second combination of keys, and have his fingers placed in readiness to
strike them, while the first set struck are accomplishing their work,
thus greatly facilitating the operation of the instrument.
By properly arranging the letters of the type wheel a large number of
combinations may be made. At each revolution of the wheel one of
the combinations may be entirely printed. The number of combinations
may be greatly increased by duplicating the often recurring double
letters E and O and L. With the numerals I place three ciphers upon

page_text: the wheel. This allows me to make numbers. with tens,. hundreds, or
thousands at a single stroke.
In order to secure a greater number of magnetic impulses from the
electric pulsations or transmissions over a single wire I construct a
magnet and its attachments in such a. manner as to cause the magnet 5
to be very sensative, or the action of the instrument indicated by the
impulse of the magnet secured by a very slight magnetic power without
giving the magnet time to become fully charged..
In order to secure a very sensative electro-magnet instead of using
the large thick core as in common magnets I make the magnet up of 1
a number of electro-magnets with comparatively thin core, or a core of
equal amount of material to a large core but spread out in a thin body,
so that the entire body of the core or cores will be quickly affected
by the passage of the electric current through the helices.
In order to use a much shorter duration of currents to secure a 1
magnetic movement than is usually employed, I omit the usual spring
connected with the lever of the armature, and construct the lever so
that it will be slightly more than counterpoised to hold it free from the
magnet when having no magnetic power. The very slight magnetic
power of the magnet caused by a current of very short duration will 2
be sufficient to bring down the lever. The instrument being influenced
in its character of movements by the lever, and being driven by other
power than that of the magnet requires no force from the movement
of the lever but only a change of position. The movement of the
power driven instrument brings back immediately to place the lever, 2
and it is again set free for another magnetic action.
Two advantages are gained by such construction, first, the speed of
the magnetic pulsations as to number is greatly augmented, and secondly,
only slight electric power is necessary, being substituted by cheaper
power. I construct the printing devices of the telegraphic apparatus
herein described, so that it may be operated upon by means of operating
keys, or automatically operated by means of previously prepared forms, and
still secure a perfect printed telegram. The perforated strips prepared for
the common automatic register may be used by making the perforations
to correspon with the intervals of movement required in the receiving a
instrument to print the given message, and by then passing the prepared
strip between conductors connecting with the line the strip being moved
at an equal speed with that of the receiving instrument..

page_text: I make an improved form of strip for automatic registers and printers
by printing upon the strip in such manner as to produce conducting
and non-conducting surfaces, over which pass two conducting connectors
which acting together make the circuit closer. As a convenient form
of construction for such connectors I employ wheels which always
ensure conducting contact without the movement usually required for
connectors to drop into perforations. Thus great speed of automatic
action is attained.
In order that a prepared message of either of the kinds mentioned
may be easily read to ascertain its character or correctness, I print on the
strip opposite the perforations or conducting faces the letters indicated
by such marks or perforations.
The advantage of securing automatic operation of printing telegraphs
is apparent in the fact that labor of copying the messages of a common
register is thus obviated.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Coddington in the Great Seal Patent Office
on the 17th October 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
CODDINGTON, of No. 3, Bedford Place, Russell Square, in the County
of Middlesex, send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of April, in the year
of our Lord One thousand eight hundred and seventy-three, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto the said Robert Coddington, Her special licence
that I, the said Robert Coddington, my exccutors, administrators, and
assigns, or such others as I, the said Robert Coddington, 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 Invention for "IMPROVEMENTS IN
TELEGRAPHIC APPARATUS," a communication to me from abroad by Merritt
Gally, of Rochester, New York, United States of America, upon the

page_text: My Invention has particular reference to "multiplex telegraphy," or
the employment of a number of operators sending without conflict a
number of different messages upon a single wire, but many of the
devices are equally well adapted to other systems and instruments, and
I do not therefore mean to limit myself to their application or use. The
devices are also subject to various modifications, and I do not mean
therefore by their particular description to limit myself to what is
particularly shewn, but shall claim broadly that in which lies the gist
of the Invention.
It has long been known that the capacity of a single wire as to the
number of electric impulses which it may transmit is exceedingly great,
and that a large number of operators might be employed on different
messages in using such capacity, if conflict in their operations could
be avoided. The only attempt to accomplish this result has been to
construct a number of instruments in such manner as to limit cach to a
certain interval of divided time, each instrument differing as to its
interval, and to place one of these instruments at cach-station. One of
the leading objections to such a system is that the number of stations on
a line are thus limited to the number of intervals into which a given
time is divided, and also that each instrument is able to use only the
interval alloted to it in its construction. The instruments upon some of
the intervals would be seldom used, and therefore great loss of time
would be occasioned. The construction of such instruments also
involves the use of automatic circuit closers, occupying different
segments of a circle, the number of segments being equal to the number
of intervals into which the time is divided. It is evident that with
the use of electro-chemical registers a large number of intervals might
be employed, but if their corresponding segments are made to represent
in each circuit connections enough to correspond to the number of
types of a type wheel, or the required number of connections to represent
any letter of the common telegraphic "dot and dash" alphabet, such a
circuit closer would be immense, and necessarily slow or inoperative.
My Invention provides, firstly, for the use of any number of instru-
ments on a line whether the number of "intervals" be great or small,
for the safe and accurate unison of all instruments in the circuit, for
to the immediate ascertaining by any operator of 'knowledge as to
whether any "interval" is employed or unemployed, and for the adjust-
ment of any instrument on the line to any unemployed interval.

page_text: Instead of using a large circuit closer with different segments repre-
senting different intervals, I use a small circuit closer with conductors
only sufficient to represent the different letters of a type wheel, or the
clements from which the "dot and dash" alphabet may be formed as
for an instrument for single transmission. This circuit closer is shown
at C', Figs. 1 and 2. It has fifteen circuit closing conductors which
when made to represent the short strokes of the "dot and dash" alphabet
in common use may be made to form any letter by combining some and
omitting others during a single revolution of the circuit connector D.
The conductors are placed diagonally to the line of the plane of the
circuit closer, and as the connector D makes contact upon a perpendicular
to such plane, it will be seen that unless some of the conductors be cut
out of the circuit the connection would be continuous as the connector
touches one conductor before it leaves another, although the con-
ductors are insulated by separation one from the other. The entire
number of conductors connected together would form a dash as long
as the largest letter of the alphabet. Any one singly would form a dot,.
and any three taken together a dash. Different combinations therefore
from the fifteen will form any letter desired. The circuit closer adapted
to a printing register must either have a sufficient number of conductors
to represent the number of letters of the type wheel or the circuit closer
must be allowed two or more revolutions for each interval.
A few of a set of operating keys A, B, C, are shewn on plan
Fig. 2. The entire number would equal the number of letters of the
alphabet, and each. key is meant to represent its entire letter whether in
print, sound, or representative characters, as dots and dashes, or what-
ever signs are employed. I do not attach the keys directly connected with
the conductors of the circuit closer, which would require the stroke of
a number of keys to produce a single letter, nor do I give to each key
a separate group of the circuit closing conductors, which would greatly
increase the number of conductors of the circuit closer. Both these
plans are common but very defective and wanting in simplicity. In my
instrument I make a break between the keys and the circuit closer,
and a break in the line in the circuit closer itself. I project from the
circuit closer the metallic lines L equalling in number the conductors
of the "closer." I make the key bars A² cach to connect when
depressed with such a combination of these metallic lines as shall produce
through the conductors of the circuit closer C¹ the required number

page_text: 4
of dots and dashes to form the required letter, or to connect with the
metallic line which corresponds to such letter on a type wheel, I project
small spring wires from the metallic lines toward the key bars to ensure
contact with the proper combination as shewn. The combination for
key bar A2, Fig. 3, is the first, third, fourth, and fifth metallic lines.
The conductors of the circuit closer for those lines a dot, short space, and
dash which represents the letter A. The different key bars thus form
the different letters. The metallic lines L directly with the circuit
closer C² or first connect with a number of plates M insulated from cach
other, which plates touch circular plates of the circuit closer as shewn,
the circular plates being each connected with one of the diagonal con-
ductors. This allows the body of the circuit closer to be turned by
means of the winch F for adjustment. For multiplex transmission,
however, I use a self-adjusting unison device which I will hereafter
describe. In either case the instruments of the line are supposed to be
moving synchronously.
The plan Fig. 2 shews the method of setting the circuit closer to any
desired interval for " multiplex transmission," and Fig. 5 shows the
partial gear which with Fig. 4 gives the method of setting the register
to its receiving interval.
1
A group of conductors n, n, &c., represent the intervals to which the.
instrument may be set, which in this case number eight, although they
may be more or less. The group of switches a¹, a³, &c., are the receiving
switches answering also the purpose of connecting the line on all
intervals not employed by the instrument. The switches a¹ connect
through the metallic line x with the main line at N. From the con-
ductors n converge the metallic lines 1, 2, 3, &c., terminating. in points
in the track of a small revolving connector P. These points are reached
in rotation succeeding each other at each revolution of the circuit
closer C¹. This is accomplished, as shewn in Fig. 1, by the spur H
connecting with one of the teeth of pinion J. The pivot of P connects
through line W with other part of the main line at O. The switch bis
the transmitter, and the connectors c, c, &c., are the connectors for the
receiver T through line Z. If all the switches a¹. are turned on to their
conductors n the main line will be constantly closed through the lines x,
w; without effecting the instrument. If any one of the switches a¹ is
turned on to its receiving conductor conc.of every eight revolutions of
the circuit closer will pass the impulses of the line through the receiver

page_text: for that interval by turning the connector P to that interval. If any
one of the switches a¹ is turned both off the line and receiving conductor
the line will be broken by the instrument for that interval, and the
switch 6 being turned on to such line connector the operating keys
may close the main line through the circuit; closer C¹, for its transmission
of impulses representing letters which will be received by any instru-
ment having such interval set to its receiver. The switches a¹ should
all be turned on to their line conductors when not employed. To know
whether any interval is being used I turn its swith a¹ on to its
receiving conductor which it will touch before breaking the line, and
therefore not interrupt a passing message, and if the receiver responds
a message is passing on that interval. If so I turn it back on its line
conductor and try another. If.I find an interval unemployed I turn
off its switch a breaking the line and then turn on to the line conductor
for that interval the transmitting switch b, I signal the station with
which I wish to communicate by using one of the intervals which I
have always reserved for "calls," and when ready I begin the message.
A particular interval should be reserved for calls with a call register
connected with each instrument and always set upon its interval. This
keeps all the stations constantly in communication for calls whatever
else may be passing upon the line. A single instrument may thus be
set to any transmitting or receiving interval, or may be set to transmit
on one interval and receive on another, or a number of others if a
number of registers are employed. As the keys affect the circuit only
on the transmitting interval they may be depressed at any time during
the other intervals and will produce no effect until the proper time. A
key being worked depresses bar c³, Fig. 3 brings the catch d' over the
key bar as it descends, drives the end of lever B² under its catch f
which holds the key bar down until the interval has arrived and passed,
and the cam wheel S'then releases the catch and the key bar returns to
place.
I have two methods of setting the register to correspond with the
interval of the instrument, one by causing the spaces between the
letters of the type wheel of one instrument to correspond with the
letters, of another, and that the printing. impulses of one instrument
will not cause the other to print. The other method is by the use
of partial gear, as shewn in Fig. 5. The wheel D³ may be set to any
one of eight positions on its shaft by means of a snap clutch F2, Fig. 4.

page_text: It has connection with the motor as also the wheel G. The relative
velocity of G and D2 is made by proper gearing to be eight to onc.
At each revolution of D² the wheel H² is made to mesh with G2, which
gives by one of its revolutions a single revolution to the type wheel.
The entire number of revolutions of the wheel G³ are equal to the
revolutions of the circuit closer, therefore by means of the clutch F of
Fig. 4 the register may be set to any interval for its movements. For
a marking or clectro-chemical register the partial movement is given
to the paper roller.. For a paper holder I use the hollow cylinder K³,
Figs. 5 and 6, with the paper roll within, the paper passing out through
the slot in one side of the cylinder around the outside, then clamped
at 15. When a message is finished the paper is drawn out under the
clamp, torn off, and the outside of the cylinder is thus supplied with
fresh paper.
The cylinder turns only during printing or marking contact, and the
line of printing is around its circumference. On one end of the cylinder
is a flange which is divided at M² having a diagonal lip. Under the
cylinder is a "grooved bar L³ at each revolution of the cylinder, and at
the end of each line of print the diagonal lip strikes into a succeeding
groove which moves the cylinder longitudinally the space of a single
line. Thus the printing is continuous, line after line, in page form.
For giving equality of movement to the motor I use the revolving
pendulum B', Fig. 1, and to secure unison to all the instruments of the
line I use a line pulsator. Line pulsations have been used heretofore
for controlling instruments, but in an entirely different manner, and
with different results. I place a pulsator upon the line, the pulsations
of which shall be of length equal to the entire duration of one of the
intervals. This allows me to correct the instruments without retarding
the movements during the other intervals. As the correction is required
only occasionally, I use an occasional period of the call interval for the
pulsator. The magnet E is connected with the call interval circuit, and
when an impulse is passed through the line continuing during an entire
interval period, the magnet lever standing in the path of the spur H,
Fig. 1, stops it, and as the lever K is furnished with a lifting cam lifts
the spur, turning it upon its pivot and freeing it from the motor shaft.
The circuit closer is also stopped at this point, but the motor goes on
unimpeded; as soon as the entire interval period has passed the magnet
lever drops and all the circuit closers commence the next interval cor-
33

page_text: rected. The advantages of such an escapement will be readily seen.
In all unison devices in which the motor is stopped or retarded there
is an irregular movement of the motor, and a consequent irregularity of
the working of the instrument.
To produce speedy magnetic movements I proceed as follows:-The
speed of a magnet as to its capacity for producing pulsations is in pro-
portion to its size, a large magnet being very slow, and a very small
one being very rapid. The small one, however, is proportionately very
weak, I therefore take a group of small quick magnets, and make them
to act upon a common armature, each acts quickly, and all together
give great power. The circuit wire may pass separately to cach one or
from one to another as desired. This is not a single combination magnet
made up of many cores for strong action, and still slow, but a series of
little magnets acting quickly, the power being procured by the number
of distinct actions being in concert.
Such magnets may be used, not only with advantage in connection
with telegraphic apparatus, but wherever speedy magnetic action is
required.
}
In connection with the governor of the instrument I use a safety
circuit which cuts an instrument out of the main line if it is accidentally
stopped, or goes too fast or too slow, thus leaving the line to the other
instruments uninterrupted. The upper arm of the pendulum at 12 has
no contact with anything while the pendulum revolves at a proper
speed, but if it is retarded or accelerated the arm 12 touches the side of
the cavity of the head of the support, and closes a circuit between the
insulated centre bearing and support head, this circuit connecting the
main line as shewn.
CLAIMS.
What I claim as my Invention, and desire to secure by Letters Patent
is,-
First. With a line of instruments arranged for multiplex transmission
by allotting to different instruments different intervals of time for their
operation I claim the combination of a device or devices for changing
such instrument to any unemployed interval.
Second. The operating keys, each having its group of connectors, by
which it selects from a common group of conductors the proper number
and order to produce any letter indicated by such key.

page_text: Third. The combination with an instrument arranged for a multiplex
system of "intervals" of a device for securing one interval to the
transmitter, while another is being used for the receiver.
Fourth. The combination with a multiplex transmitter of an auto-
matic circuit closer with interval circuits cutting out the transmitter
for intervals not allotted to it for transmission, allowing the working
of the keys during the unallotted intervals without affecting the line
circuit.
Also the combination with such instrument of a device for holding
the operated key until the proper interval has arrived in addition to
the time of actual transmission..
Fifth. With a multiplex instrument the combination of an automatic
circuit closer for transmitting, which does not admit through it the
receiving pulsations.
Sixth. The type wheels of a number of multiplex instruments bearing
a different relative position to each other, the spaces of one wheel repre-
senting the letters of another, so that the impulses causing the printing
by one will not cause the others to print.
Seventh. A multiplex register combined with devices for setting its
movements to any interval desired.
Eighth. A paper holding cylinder containing internally the paper to
be supplied to the outside.
Ninth. A paper holding cylinder having its line of printing around
its circumference and a longitudinal movement for placing the position of
the lines.
Tenth. The tripping escapement for correcting the time of the circuit
closers of the instrument without retarding the motors, substantially as
specified.
Eleventh. The combination with an automatic circuit closer of a
revolving pendulum, substantially as specified.
Twelfth. The combination with a line of multiplex instruments of a
line pulsator, the pulsations of which occupy the entire period correspond-
ing to an allotted interval, but not necessarily using all the the periods of
such "interval."

page_text: Thirteenth. The combination with an armature of a group of magnets
acting in connection therewith, substantially as specified.
In witness whereof, I, the said Robert Coddington, have here-
unto set my hand and seal, this Sixteenth day of October, in
the year of our Lord One thousand eight hundred and seventy- &
three.
ROBT. CODDINGTON. (L.S.)