Im- PROVEMENTS IN TELEGRAPHY
Year: 1874

page_text: LETTERS PATENT to Robert Coddington, of 3, Bedford Place, Russell
Square, in the County of Middlesex, for the Invention of "Im-
PROVEMENTS IN TELEGRAPHY."-A communication from abroad by
Merritt Gally, of Rochester, State of New York, United States of
North America.
COMPLETE SPECIFICATION filed by the said Robert Coddington at the
Office of the Commissioners of Patents, with his Petition and
Declaration, on the 25th September 1874, pursuant to the 9th
Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
CODDINGTON, of 3, Bedford Place, Russell Square, in the County of
Middlesex, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
TELEGRAPHY," and have petitioned Her Majesty to grant unto me, my
0 executors, administrators, and assigns, Her Royal Letters Patent for

page_text: the same, and have made solemn Declaration that it has been com-
municated to me from abroad by Merritt Gally, of Rochester, State of
New York, United States of North America.
NOW KNOW YE, that I, the said Robert Coddington, do hereby declare
that the following Complete Specification, under my hand and scal,
fully describes and ascertains the nature of the said Invention and
in what manner the same is to be performed in and by the following
statement:-
The automatic system of telegraphy by which messages are transmitted
having first been prepared by punching the representative message in a
strip of paper has never been extensively adopted on account of its
many disadvantages, among which are the facts that too many persons
are required to successfully accomplish the work, and that too much
time is wasted in making ready the different parts to be performed; for.
example, one person must be employed in punching the strip; it is then
usually taken by a second person and arranged on a bobbin for the
transmitter. It must then be taken to the transmitting operator and
adjusted to his instrument, and finally it is ready for transmission.
Unless the message be a lengthy one it could during the time of pre-
paration have been transmitted two or three times by the common
process of direct transmission. As a large majority of business and
private messages are very short, each one destined to a particular
station, and cannot be sent with others in mass, the defects of the
common "automatic system" are apparent. In order to overcome such
defects, and also those common to other methods I have invented what I
term an “accumulative system," which may be successfully used either
in single or "multiplex" telegraphy, and for either signal or code
receiving.
In the accompanying Drawings Fig. 1 represents an instrument
which may be used either as transmitter or receiving recorder, in which
the "punched strip" is used for transmitting, but which strip is pre-
pared by the transmitting instrument itself and requires no rehandling
or service of any other person than the transmitting operator.
A is a transverse section of a sliding bar, which is furnished with a
number of punches arranged in groups corresponding to different letters
or characters, which are moved to place by sliding the bar until the
proper group takes its position above the follower and die, which is

page_text: furnished with holes enough to accommodate the largest group, and
therefore accommodating any of the different groups on the slide. I
will not further describe the punching apparatus as any suitable
apparatus can be used in the instrument for this purpose.
The message strip passes from the puncher over the wheel M, and is
accumulated below the wheel, as shewn, in quantity more or less, as the
case may, until such time as the operater wishes the matter to be
transmitted.
By using electro-chemical or other very rapid recorders the time of
transmission will occupy only a small portion of the time occupied for
manipulating, so that the line may be used a large portion of the time
for transmitting the messages of other operators without interrupting
the operator first mentioned.
If the operator at any time finds the line occupied he goes on with
his manipulation which produces and accumulates the message matter
until the way is open, when without ceasing his manipulation the
operator ejects as it were the accumulated matter into the line and then
again leaves it unoccupied for anotlier operator.
The message strip passes between the transmitting wheels C, D, the
wheel D being driven by the motor wheel a. The lever F is operated
by means of two sets of electro-maguets G and H. The wheel D is
pivotted to a rocking support E, and when in contact with wheel C
causes it to revolve by means of friction. The cam R of lever Facts
upon the support E and separates or brings the wheels into contact as
required. To set the strip Bin motion for transmitting the accumulated
matter an electric circuit through the binding posts L, L, is closed, and
the wheels C, D, revolving together give motion to the strip until the
strip is drawn taut in the direction of the dotted line from M. to C. A
light wheel N pivoted to a rocking arm P rests upon the strip and is
lifted a short distance by the strip becoming taut. This closes an
electric circuit to the magnet G, and by the action of armature lever F
separates the wheel C, D, and interrupts the movement of the strip B,
which again begins to accumulate. The transmitting circuit K, K,
connects through the styles Q and wheel C in the usual manner.
The instrument is used for receiver by simply substituting chemically
prepared paper for the strip B. The wheel a is driven by clockwork or
other motive power. To still further improve upon this plan I construct

page_text: the transmitter as shewn in Fig. 4, and by this means entirely obviate
the necessity of using the strip B for transmitting.
Detached parts of the instrument, shewn in Fig. 4, are represented in
Figs. 2 and 3. In Fig. 2 V, V, &c., represent five moveable bars,
which may be moved singly or in numbers to different positions right
and left. One of these bars is shown at V₁, side view, cut to form
inclined cams to be acted upon by the manipulating keys W, X, Y, Z.
Dotted lines 1, 2, 3, shew the different positions to which the end of
the bars may be moved by different keys forming different combinations
from the fire bars in the track of the compound connector S. A simple
connector could be employed by varying the number of the bars. The
compound connector S has two projecting points, one crossing the
dotted line 1 and the other crossing only the line 2. The body of the
connector S crosses the line 3. As the connector S is moved in the
direction of the dotted lines it will be seen that it will make different
connections as to duration of the bars, which position is governed by the
manipulating keys. If a bar is moved to the dotted line 1 the con-
nector S makes only a short contact, the bar touching the longest point
of the connector, and for a moment connecting a circuit, of which the
bar and connector form electrodes, a receiver placed in such circuit
siguals or records a "dot." If a bar is moved to the second dotted linc
it produces two dots as it comes in contact with two points of con-
nector S. If a bar is moved to the third dotted line it forms a long
connection with the body of the connector S and produces a "dash."
Any letter of the Morse "dot and dash" alphabet may be produced
by moving the fire bars V to such positions in respect to the dotted
lines 1, 2, 3, as will form the requisite number and arrangement
of dots and dashes which represent the letter. The connector S makes
successive movements along the track and at each movement makes
connection with whatever combination of bars the manipulating keys a
place in its way.
The instrument Fig. 4 is constructed with keys representing an entire
23

page_text: As so far explained the mechanism is adapted only to single tele-
graphy; the representation in Fig. 4 shows the mechanism with
additions and modifications adapting it to my accumulative system,
cither for single or "multiplex" transmission. A wheel C¹ is placed
between the connector S and the bars V, which wheel is furnished with
a succession of small moveable picces y, the ends of which form contact
points for the contacts which are to be made with the connector S. A
reciprocating slide or other suitable device may take the place of the
wheel C¹ if desired. The wheel C is pivoted at its centre and has a
constant tendency to turn in one direction. This is caused by the action
of the manipulating keys upon the weight f, which is attached to an
arm which is pivoted on the axis of the wheel. A small pawl ŋ takes
hold of notches in the side of the wheel and as a key is struck it
raises the weight a short distance and the pawl catches into a mesh.
which is higher upon the side of the wheel. The wheel is however
prevented from turning by means of the stop U, which comes in contact
with the first of that portion of the small moveable slips y which have
not been acted upon by the bars V. When one of the manipulating
keys is depressed a corresponding letter is represented by such a move-
ment of a part or all of the number of bars V which drive forward to
corresponding position the connecting slips y which lie in their course.
At the stroke of any key, except one, the bar m is also driven slightly
forward to the right and relieves two of the slips y from the stop U in
addition to the combination of slips forming the letter. The movement
of these two additional slips from the space between the letters without
working an extra key for that purpose. There is an additional key
however which operates only on the bar m, which when struck after a
letter forms a second or double space which divides one word from
another, or if struck a number of times in succession forms an extended
blank. When the pressure of the finger is removed from a key that
has been depressed the bars V and m are drawn back to former position
by means of springs, and the wheel C is allowed to turn until the next
unoperated slip y reaches the stop U when the wheel comes to a pause
until another key is depressed.
When the operator does not wish to accumulate his manipulated
message matter. but wishes to transmit each letter as the key is struck
the conductor S is set stationary at r. As soon as the combination for
each letter is formed the wheel turns it back under the connector and
the signals are passed through the wire K, K.

page_text: For accumulative work the connector S is allowed to turn back with
the wheel, the message or part of message being accumulated in front
of the connector. The accumulation may continue if desirable until the
completion of an entire revolution of the wheel, or more properly
speaking until the connector has been carried around to the guard j.
The inclined face of this guard returns the slips y to place after they.
have. been used, so that another accumulation can progress while the
former is being transmitted or after the transmission, as the case may be.
The connector S attached to the wheel by means of a catch /, which is
pivoted at t, and held in contact with the wheel by the spring i. In
the side of the wheel.C is a toothed circle, as shown in Fig. 3 at n. The
catch will therefore take hold of the wheel in any position of the con-
nector S in respect to the wheel, and the connector will be carried
around with the wheel unless the catch is relieved. As the connector S
is carried around its pivot by the movement of wheel C it winds up a
tension spring or weight, which as soon as the catch is relieved from
the wheel turns back to its former position, the connector arm carrying
the connector along the track of the accumulated matter, passing it into
the line K, K. Attached to the catch lever is an armature T, which
may be acted upon by magnet H.
•
Whenever the operator wishes to allow his accumulated matter to pass
into the transmitting line K, K, it is only necessary for him to close a
local circuit which passes to the magnet H through L, L, which will
relieve the catch and allow the return movement of the connector S.
I construct the catch in such manner as when relieved it will not take
hold again of the wheel until it arrives at r, or until such time as the
operator wishes to arrest it.
For multiplex or interval telegraphy my accumulative system is of
even greater importance. For single transmission its advantage is to
allow an operator to accumulate parts of his message while he is not
using the line wire, or if he attends to a number of branch lines may
prepare a message for one branch while the wire is otherwise occupied ;
and then while he is manipulating for another branch can by a touch
set off messages for the different lines as time shall be given for them or
the way is open, and this without interfering with the work on which
he is employed.
For multiplex telegraphy its principal advantages are, first, that it
allows the increase of the intervals from single letters to accumulated

page_text: messages or parts of messages and still preserves perfect regularity to
the intervals. The pulsations which are sent through the line for
governing the intervals of the instruments are therefore very much less
in number, and more perfect accuracy of adjustment can be attained
and much time saved.
For marking the time of the intervals and preserving proper order to
the number of multiplex instruments on a line I use either of two
methods.
First, I connect the circuit wire L, L, with the main line instead
of a local; I then use a polarized magnet and by a reversed current
through the line mark the proper intervals. I make the catch h
so that it will be fully relieved only after a certain number of move-
ments of the armature T. I then set this number in its recurrence to
the number of the interval on which I wish the transmitter to act, and
the instrument is ready for operation. With very rapid recorders a very
large number of operators can be constantly employed on a single line
without ceasing their manipulations, and perfect accuracy be attained.
My second plan for controlling the intervals is to use an additional
line wire with direct or reversed current, this line wire connecting with
the magnet H, to which regular pulsations may be given by an automatic
pulsator.

page_text: Thirteenth. The combination with a main line of an additional line
wire for a circuit to govern the intervals for multiplex telegraphy, inde-
pendent as to the transmitting circuit, substantially as specified.
In witness whereof, I, the said Robert Coddington, have hereunto
set my hand and seal, this Twenty-third day of September, in the
year of our Lord One thousand eight hundred and seventy-
four.
ROB. CODDINGTON. (L.S.)