IMPROVEMENTS IN PRINTING TELEGRAPHS
Year: 1854

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, and of Glasgow, North Britain, Gentleman,
for the Invention of "IMPROVEMENTS IN PRINTING TELEGRAPHS."-A
communication from Meinrad Theiler, a resident abroad.
Sealed the 27th October 1854, and dated the 18th May 1854.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, ou
the 18th May 1854.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of Glasgow, North Britain, Gentleman, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN PRINTING TELEGRAPHS,"
a communication from Meinrad Theiler, a resident abroad, to be as
follows:-
This Invention relates to an improved construction and arrangement of
mechanism for transmitting and printing messages or dispatches by electro-
magnetic agency, and consists in the employment of wheels situated at each of
the corresponding stations, which wheels are caused to revolve at the same
speed. The difficulty which has hitherto presented itself in the employment
of telegraphs based on this principle has been obviated by the improvenients
herein-after described, whereby the uniformity of movement of the wheels is
required only for a very short space of time, at the most for only half a second.

page_text: A series of keys with the requisite letters or characters marked thereon are
employed for conveying the intelligence; a revolving shaft is fitted beneath the
keys, and a series of tappets or arms are arranged thereon in a spiral form,
each tappet being acted upon by a distinct key, the under side of the keys
being fitted with a projecting catch, which holds the respective tappet on the
depression of the key. At the end of the shaft is fitted another tappet
(distinct from those already mentioned), which serves to hold the shaft
stationary, by means of a spring lever which hooks on to it; this lever is,
however, released, and the shaft allowed to revolve; whenever any one of the
keys are depressed the shaft continues to revolve, until the particular tappet
corresponding to that key comes in contact with its under catch, before
mentioned. This has the effect of stopping the revolution of the shaft and
establishing the electric current through it. The apparatus for breaking and
establishing the current consists of an escapement wheel, which revolves upon
the end of the shaft before mentioned. This wheel is driven by clock-work,
and is insulated at the part where it turns upon the shaft, and is fitted with a
blade spring, which is attached to the side of the escapement wheel by an
insulated junction, the other end being connected to an arm on the end of the
shaft carrying the tappets. A small stud is fitted to one side of the escapement
wheel, and the arm, before mentioned, is kept just out of contact with the stud
on the wheel, but when the stud and arm are brought into contact with each
other (which occurs, firstly, at the moment a key is pressed upon, and,
secondly, when the shaft is stopped by the catch on the under side of the key),
a communication is formed and a current established; it will thus be seen
that the spring has the effect of breaking the communication between the
wheel and the tappet shaft during the rotation of the latter so long as the
keys are left untouched. The current passes through the two shafts and on to
the next station, and returns by another wire, which is attached to a piece of
copper at the other end of the key board, where is situated the negative pole
of the battery. A square piece of metal presses upon a piece of ivory let into
the copper, and is so arranged that when the key board is at rest, the metal
rests upon the ivory, and the current is broken; but the moment-a-key-is-
depressed, the metal slides off the ivory on to the copper, and establishes a
communication. Thus, as the contact between the copper and metal arm
commences before the release of the shaft, and before the stud in the wheel
before mentioned has had time to become disconnected from the arm onl
the shaft, an electric current is established for an instant merely, or during the
striking of a key, and occurs again when one of the tappets comes in contact
with its corresponding key. The printing mechanism is actuated by clock-

page_text: work, and an escapement wheel, similar to. the telegraph, driven at the same
speed also. The wheel containing the signs or characters in relief is carried on
the same arbre as the escapement wheel; it is kept in contact with an inking
roller, which is made hollow, and carries the color inside. The surface of the
roller is covered with gutta percha, which is pierced with a number of very
small holes, to allow the color to ooze out. The characters on the wheel
correspond in order to the characters on the keys, and when a key is dépressed
the wheel stops with that particular character downwards, and the paper, which
is cut into a long tape or strip, is pressed against it by a lever and magnet each
time a letter is to be printed. A blank key is fitted in the key board, to
produce the spaces between the words on the dispatch. In many cases it will
be found necessary to employ two printing wheels, either one or the other being
actuated at pleasure by reversing the direction of the current; for this
purpose certain modifications will be requisite. The key board will be composed
of two ranges of keys, similar to a pianoforte. Each set of keys acts upon a
separate rod, and each rod is fitted with the same mechanism for establishing
and breaking the current, as described above. The printing apparatus in this
case will also be modified. Two maguets are employed, one of which repels
whilst the other attracts. For this purpose each magnet has a permanent
magnet for an armature, or one magnet alone may be used.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office on
the 4th November 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
and of Glasgow, North Britain, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighteenth day of May, in the year of our Lord
One thousand eight hundred and fifty-four, in the seventeenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said John Henry Johnson, Her special license that I, the said John Henry
Johnson, my executors, administrators, and assigns, or such others as I, the
said John Henry Johnson, my executors, administrators, or 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

page_text: Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN PRINTING TELEGRAPHS," a communication from Meinrad. Theiler,
a resident abroad, upon the condition (amongst others) that I, the said John
Henry Johnson, by an instrument in writing under my hand and seal, should
particularly describe and ascertain the nature of the said Invention, and in 5
what manner the same was to be performed, and cause the same to be filed in
the Great Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent..
NOW KNOW YE, that I, the said John Henry Johnson, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say:-
The said Invention relates to an improved construction and arrangement of
mechanism for transmitting and printing dispatches or messages by electro-
magnetic agency, and consists in the employment of wheels situated at each of
the corresponding stations, which wheels are caused to revolve at the same
speed; a series of keys with the requisite letters or characters marked thereon
are employed for conveying the intelligence. The apparatus for breaking and
establishing the circuit of the current consists of aif escapement wheel driven
by clock-work, and insulated at the part connected with its carrying shaft.
The printing mechanism is actuated by clockwork, and an escapement wheel
similar to the telegraph, and driven at the same speed also. The wheel
containing the signs or characters in relief is carried on the same arbor as the
escapement wheel; it is kept in contact with an inking roller, which is made
hollow, and carries the color inside. The surface of the roller is covered with
gutta percha, which is pierced with a number of very small holes, to allow
the color to ooze out. And in order that the said Invention may be more
readily understood, I shall now proceed to describe the several Figures on the
Sheets of Drawings hereunto annexed.
Fig. 1 on Sheet 1 of the Drawings represents a sectional plan of the key
board; Fig. 2-is-a-transverse-vertical-section-of-the-same, taken along the
line 1, 2, in Fig. 1; and Fig. 3 is an end elevation of the left hand side
of Fig. 2.
An escapement wheel 6 (Figs. 5 and 6) is fitted to the spindle a, an escape
movement being employed for regulating its motion.
A small tappet c (Fig. 2) is fixed to the axle a, and after each revolution of
the shaft or axle is caught by a hooked lever d. The keys have all the same
function, namely, of raising or elevating the horizontal shaft e; they disengage

page_text: also the hook d, and thereby determine or regulate the rotation of the shaft a.
This shaft is fitted with a series of arms, blades, or tappets x, equal in number
to the letters or signs to be telegraphed. The tappets are arranged in the
form of a helix round the circumference of the shaft and along its entire
length, so that during their revolution they press against their respective keys.
In Fig. 1 some of the keys are supposed to be removed in order to shew more
clearly the shaft a and tappet z. Each key is fitted with a small projection f
on its under side, so that when the key is pressed down it stops the rotation of
the shaft a, by coming in contact with its corresponding tappet. When the
keys, however, are left at rest, or released from pressure, the shaft continues its
revolution until the small stop tappet c comes in contact with the hooked
lever d. This apparatus requires only two junctions to establish the electric
current for the reproduction of each letter or sign; the first junction takes place
at the moment the key is depressed, and the second junction occurs when one
of the tappets x comes in contact with the stop f of the depressed key. To
accomplish these junctions the shaft a carries the following mechanism, which
will be readily understood on referring to Fig. 4 of the Drawings, where the
mechanism is represented on an enlarged scale:-The escapement wheel b is
not mounted on its own axis, but is fitted on to an ivory socket g on the end
of the shaft a, round which shaft the socket turns loosely. It will thus be seen
that the shafts a and a' are insulated from each other by the ivory socket,
before referred to. The shaft a', however, is in metallic communication with
the escapement wheel. This wheel carries a pin or stud h, which establishes a
communication with the escapement wheel on coming in contact with the
arm i, fitted on to the tappet shaft a. A weak blade spring k is also fixed to
the escapement wheel, but is insulated therefrom; it acts in either direction
upon the arm i, and always tends to keep it just out of contact with the pin h,
as shewn in Fig. 5, when no pressure is exerted against it; but when the small
stop tappet c, on the other extremity of the shaft a, is caught hold of by the
hooked lever d, the power of the clock-work which actuates the escapement
wheel b, will overcome the 'resistance of the spring k, and force the stud or
pin h in contact with the lever arm, thereby at once establishing a communi-
cation between the shafts a and a¹. The same result is obtained when any one
of the tappets come in contact with the stop piece f, on the corresponding
key. The object of the spring k is to break the communication between the
shafts a and a¹ during the rotation of the shaft a, by which means the shaft a
is allowed to rotate with a continuous movement, whilst the movement of the
escapement wheel 6 is intermittent. This spring also prevents the resistance
of the shaft a having any effect upon the wheel 6, and tends to produce a

page_text: smoothness of motion. The electric current enters at the left hand extremity
of the axle or shaft a, and is then conducted to the shaft a' (when the keys are
not depressed), and thence the current is conducted to the connector m by a
spring, which constantly presses upon the shaft a¹; finally the current is
conducted from the connector m by the telegraph wire to the next station B,
from which it returns by a second wire to another connection n and piece of
'copper o. A metal bar p, which slides freely upon it, presses constantly on the
copper o, against which it is held in contact by the blade spring p¹. The bar
p is connected with the lever g of the spindle e, and by this last with the
connector and negative pole of the battery A. Whilst the set of keys is
untouched the bar p remains in constant contact with a piece of ivory s let into
the copper, so that the current is broken or interrupted at that time; but the
instant that one of the keys is depressed, the lever q, fixed on the spindle e,
causes the bar p to move off the piece of ivory on to the copper. Thus, as the
contact between the bar p and copper o is made before the raised hook d
releases the stop tappet c, and before the stud h has had time to leave the
arm i, it follows, that an electric current will be established for an instant
only; in fact, at the moment of striking the key. This current occurs a
second time, when one of the tappets a comes in contact with the pro-
jection of its corresponding depressed key. t represents the working centre
of the keys; u, the working centre of the lever arms q; and v, the working
centre of the hooked lever a. A modification of the arrangement herein-
before described is represented in transverse vertical section at Fig. 7. The
sliding bar p is kept in contact with the pieces o and s by a weight, and is
attached to the vertical lever arm 9 of the bell crank, which, instead of its
horizontal arm being a single lever, it is formed like a fork g', in which fork
works the end of the arm q. which carries at one end the working centre ',
and is fitted at the extremity to the moveable spindle or shaft e.
The lever 1
is therefore not connected to the rod or shaft e. When any one of the keys
is depressed, the lever 92, on the spindle e comes in contact with the upper
branch of the fork q', and causes the point which forms the upper extremity of
the lever to pass the point or incline w' on the end of the blade spring w,
the inclines_on_the_lever 9 and spring w causing the bar p to advance;
when the key is released, however, it is drawn back again by a lateral or other
spring, and the weight of the spindle e, acting on the lower arm of the fork g',
brings the lever q on to the other side of the double incline w', and brings the
the bar p on the ivory s. The object of this arrangement is to regulate the
duration of the current, whatever may be the pressure exerted upon the keys.
The printing mechanism which I shall now proceed to describe is illustrated

page_text: by Sheet 2 of the Drawings. Fig. 1 on this Sheet represents a detail of the
printing mechanism alone. This apparatus is actuated by clock-work with an
escapement, similar to that shewn in Sheet 1 of the Drawings, and which
moves with the same velocity. On the spindle of the escapement wheel is
fitted a type wheel a, having the several letters and signs fitted on to its cir-
cumference; during its rotation this wheel is in contact with a roller b, which
carries the ink. This roller is hollow, and is covered with gutta percha, which
is pierced with a number of very small holes, and contains the ink inside. On
the spindle of the escapement wheel is fixed a ratchet wheel c, shewn in Fig. 2
of the Drawings. This wheel carries on one of its faces a stud or pin d, which
is in contact with one of the bent extremities of the forked lever d', which is
fitted with an armature e¹ at its lower extremity; this armature being acted
upon by the electro-magnet e. When the electric current takes place the
magnet e attracts the armature e', and the ratchet should be disengaged from
the lever d', and commences to turn. If the current is of any short duration,
the lever d'immediately returns to its place, and the wheel stops when it has
completed a revolution, the stud d again coming in contact with the fork d¹.
When, however, there is a second circulation of the electrio current, before the
wheel has completed a revolution, it is stopped by a catch or tooth in the upper
branch of the fork d' engaging itself into one of the ratchet teeth of the wheel,
thereby stopping it. It will thus be seen that this machine is worked by two
distinct currents of electricity during one revolution of the wheel, and that the
intervals are longer or shorter according to the key which is depressed. If
then the velocity in the wheels in each operation is the same, the number and
order of the keys will correspond to the number and order of the types on the
printing or type wheel, and it is obvious that this wheel may be stopped at any
desired letter or sign; the key which is pressed down must be kept depressed
until the shaft a carrying the tappets a is stationary, which cannot be longer
than half a second, supposing the wheel to rotate at the rate of one hundred
and twenty revolutions per minute. If then the key be released from its
pressure, the two wheels will complete their revolutions, rectifying, if necessary,
any.irregularity of speed. Should any exterior cause prevent the working of the
one or other of the wheels, as soon as that cause is removed they will return
to their original positions. A continuous strip of paper is passed under the
printing wheel and is pressed between a pair of rollers f, f, (Fig. 1); the
upper roller being actuated by clock-work, whilst the lower one is kept in
contact therewith by springs. A barrel spring g is fitted on to the axis of the
upper roller, and may be wound up in the ordinary manner when run down.
A double-branched stop i', which comes in contact with the projections with

page_text: which the wheel is furnished, stops the movement of the upper roller f, until
all the types of the printing wheel have passed. When the printing wheel has
regained its original position, a stud or pin with which it is furnished acts upon
the lever ', which allows the wheel h to turn the space of one tooth or stud,
and then falls into its place again; the object of this is to leave an equal
space between each of the letters in the despatch. A small clastic roller k
placed directly under the printing wheel serves as a support for the paper:
this small roller is carried on one of the arms of the bell crank lever l, the
vertical arm of which is fitted with an armature m, belonging to the magnet n.
When the electric current takes place the armature is drawn towards the
magnet n, and the lever / presses the paper against the inked letter or sign
printed by the type wheel; but this movement should not occur until the
second current takes place, for if it occurred during the first current a blot or
smear would be produced. For this purpose a small arm o is fixed on to the
axis of the printing wheel; this arm, when the wheel is stationary, presses upon
a spring p, which conducts the current direct to the printing wheel from the
connector y by a short circuit, without passing through the electro-magnet n.
In order not to be compelled to produce the two currents at very short intervals,
which would require a very strong battery, two or three spaces are left on the
circumference of the wheel. Thus, for example, if twenty-eight signs are to
be lithographed, the wheel is divided into twenty-eight cqual parts.
wheel is stopped on the first space after the letter (Fig. 1). If any letter is
lithographed and the armature be attracted, it has the whole of the time for
leaving the magnet that the tooth or roller A requires to arrive at the lever d';
consequently the spring of the armature e¹ (Fig. 2) does not require to be
stretched so forcibly, and the current itself may be very weak. For great
distances, and when the apparatus is to be driven at a high speed, the space
herein-after referred to may be still further increased. The escapement and
ratchet wheels should of course bave the same number of divisions as the
printing wheel.
The
It is necessary to have a supplementary arrangement, in order that in
printing, a greater space may be left between the words than between the
letters which compose a single word; to obtain this, a blank key, not pro-
vided with a projection f, is situated at the left end of the key board, (Figure
1, Sheet 1,) so that when this key is pressed down it presents no obstacle
to the revolution of the spindle a and tappets a, but only produces the first
momentary current of electricity, which produces an entire revolution of
the printing wheel, and causes the paper to advance without printing a letter
upon it.

page_text: The blue lines in the Figure 1 represent the course of the electric current..
The two escapement wheels are actuated by clock-work, which is put in
motion by weights, suspended by means of double pullies, so that a compensa-
tion is obtained, and the apparatus is not stopped while being wound up.
I have just described the most simple form of telegraph; but in practice this
would not be sufficient, for most cases it will be found necessary to employ
two printing wheels, either one or the other of which can be put in motion at
will by reversing the direction of the current. In order to arrive at the result
it is necessary to employ certain modifications, which I shall now proceed
to describe, reference being made to Figures 9 and 10 of Sheet 1 of the
Drawings, and to Figures 3 and 4 in Sheet 2.
The key board must be so arranged as to allow of the current being
reversed. This is effected in the following manner:-The key board is com-
posed of two ranges of keys, the upper ones of which, painted black, are
arranged between the lower ones, which are white, similar to the black and
white notes of a pianoforte (see plan Figure 8, Sheet 1 of the Drawings).
This arrangement requires two horizontal bars e and e¹, but it is necessary
that one of these bars should remain immoveable while the other is elevated.
The transverse section (Figure 9, Sheet 1,) shows how this result is arrived
at, by diminishing the length of the upper keys, and increasing that of the
lower ones.
Each of the bars or rods is fixed to a lever q. 7. These levers are in-
sulated from one another, and each of them actuated by a sliding bar p, p";
the piece of copper o must also be double, and different from that in the
apparatus herein-before described.
When the apparatus is at rest the two sliding bars press upon a piece of
copper o, but when a key is pressed down, one or other of these bars is made
to advance upon another piece of copper o¹. The two pieces of copper are
separated by an interval filled with a piece of ivory, so as to insulate them one
from another, (see Fig. 9, Sheet 1.)
If one of the white keys be depressed the bar p advances as far as the piece
o'. The electric current is then established between a and a¹; from thence it
flows thro' the spring in the iron wire 1, and arrives at the piece o¹; it
then passes by the sliding bar p, thro' the spring w, and to a connector n,
afterwards turns off to the right by the wire 3. and arrives at the 2nd station..
From this station it returns to the connector m of the apparatus, then by the
wire 2 it arrives at the spring w", passes by the sliding bar p" by the piece of
copper o, and thence to the negative pole of the battery A.
It will be obvious, that if one of the black keys be depressed, the bars p, p";

page_text: will change their position, the first coming in contact with o and the second
with o', and the current thus reversed passes to the second station through the
connector m, whilst it will not return by the connector n.
Thus, in this arrangement the bars p, p", are never insulated; on the con-
trary, they continually rest on the pieces of metal; nevertheless these ought to
be insulated one from another.
In the present case it is necessary to make use of an intermediate apparatus,
which I call a "pecker," and which is furnished with two permanent magnets,
of which the one is always repelled while the other is attracted.
For this purpose it is necessary to use two electro-magnets, both of which
have a permanent magnet as an armature; as a slight movement is required
only, the same end may be obtained by employing one electro-magnet.
Figs. 5 and 6 of Sheet 2 represent respectively this apparatus in elevation
and in plan. A, B¹, are the 2 electro-magnets. a, b, are the correspond-
ing permanent steel magnets, which serve as armatures. The 2 permanent
magnets present a pole of the same denomination to the electro-magnets,
which diminishes considerably the attraction exerted by the permanent
magnets; thus, when the electric current is broken, the electro-magnet has
two poles of the same denomination at its extremities, whilst the two other
poles are situated in the centre thereof, thereby a very small amount of force is
obtained. If, on the contrary, the current is made to circulate by means of the
wire which encircles the electro-magnet, the poles are reversed, and the mag-
netic power is considerably increased; the one will forcibly draw its armature,
whilst the other will be as forcibly repelled. As the permanent magnets are
bent at right angles, when one of the two is attracted by the electro-magnet,
its opposite end comes in contact with the point of the screw c"; a wire con-
nects the support d" of the permanent magnets with the "connector "f, and
passes from them to the local battery c. The roller which supports the paper,
lettered in Fig. 1, Sheet 2, cannot be used with a double printing apparatus,
as each time it was elevated it would print two letters; it is therefore replaced
by a fixed piece, and the printing wheels themselves are made to descend for
the purpose of printing a letter or sign. The two wheels work close to each
other, as shewn by the plan Fig. 4, on Sheet 2. There axles are fixed to the
sides of the two adjacent bent levers 7, 7, the other ends of which carry the
armatures s2, s³. tand are the corresponding electro-magnets. From
the positive pole of the local battery c a wire extends to the "connector
g²
of the printing apparatus, Figs. 3 and 4, Sheet 2; this wire first encircles, how-
ever, the electro-magnet e, and is then attached to a piston V, which serves as a
medium for establishing the electric current. When the wheel is at rest the
11

page_text: 66
current takes a short circuit by one of the two springs p, p, which press upon
the finger or tappet o, and thereby arrives at the "connector" or y. From
these connectors wires are carried to the connectors x, y, of the "pecker,"
and thereby establish the electric current when one of the permanent magnets
is attracted and brought in contact with its screw. But it has already been
shewn that this short circuit of the current by the finger or tappeto is broken,
and the circuit caused to make a larger circuit when it is produced a second time.
To the hook V is attached one of the ends of the wires of the electro-magnets t³, t³,
(Fig. 4, Sheet 2,) whilst of their other ends one is attached to the connector
and the other to the connector y³. Thus, each time that the electric current is
established there is only one of the armatures of the "pecker" attracted, and
therefore there is only one printing wheel depressed, which may be either one
or the other, according as the current passes by the armature a² or b² of the
pecker." All the pieces which by their movements serve to establish or
interrupt the electric current, are fitted with pieces of platina. The apparatus
herein-before described may be simplified in practice, as shewn by the Figures
7 to 11, on Sheet 2 of the Drawings. The first of these modifications relate
to the key board, and consists in placing the rod a, (Fig. 1, Sheet 1,) with
tappets thereon above the keys, as in Fig. 7, Sheet 2, in place of below them,
so that on opening the box the whole mechanism may be instantly seen and
any derangement rectified. At the inner end of each key is fitted a bent
tooth 6, against which the rod can rest. By another modification, the first
formation of the current that puts the mechanism in motion is no longer
immediately produced by the depression of a key, but by the action of the stop
wheel. A metal arm c (Fig. 7,) fast on the axis of the stop wheel comes in
contact with the lever d, d, in its rotation, the part at rest being insulated by
the piece of ivory e; this lever rests upon an insulated piece of metal ff,
screwed to one of the plates, and, as will be seen from the Drawing, this junc-
tion will always be of the same duration; thus the complication of the ratchet
is avoided. The rod and tappets may therefore be dispensed with. In that
case each key will act on the lever g, (Figs. 8 and 9,) near which is situated
the stopping instrument n, to stop its action. This instrument assumes a
different position at each key, according as the successive signs require it, as
shewn in the Drawing; by this arrangement the tappets or teeth of the rod
might all be arranged in a line parallel with the axial line of the rod, or may
be placed in two lines, to obtain a better equilibrium. The second modification
and simplification relates to the printing mechanism, and consists in the intro-
duction of a wheel that moves with greater rapidity than the printing wheel.
The number of teeth in this wheel corresponds with its increased speed, and

page_text: against these teeth works a detent or stop. The part marked a, in Figures 10
and 11, shews the position of this new wheel; as it requires to turn several
times for one revolution of the printing wheel, a moveable pin in the screw of
the lever c, c, checks or regulates its motion; the lever falls to bring the stop
or detent into action. When the apparatus is not working, the lever c, c, is up,
and remains thus suspended until the printing whcel prints the first letter;
the lever then falls into its lower position, in order to facilitate the working of
the stop or dent c'. When the stop lever b', b, is put in motion it removes
all obstacles, and the wheel is set in motion. A second action of the stop
lever, which occurs before the wheel has made a full revolution and whilst the
lever is below, replaces the obstacles and leaves the wheel at rest; the pressure
of the stop lever will be far less on this wheel than on the printing wheel,
because it must turn more rapidly, and therefore is more easily moved, and
will consequently obey a weaker battery. In order to prevent the stop wheel
from flying back, as might occur by the acelerated movement of the appa-
ratus, through the elasticity of the working parts, another wheel has been fixed
on to the axis of the stop wheel, in which a spring c' catches, and renders its
motion perfectly regular. For the purpose of preventing the shock of the
wheels that press against the stop lever, the axis of the printing wheel is also
fitted with a spring which holds back the stop wheel, so that while the latter
is at rest the others may continue their movements.. The advantages derived
from the improved telegraphic apparatus, herein-before described and illus-
trated by the annexed Sheet of Drawings, are:-The obtainment of an imme-
diate impression of telegraphic despatches in ordinary types or letters.
painting wheels return to their original positions so soon as they have acted.
The apparatus requires only two currents for each letter or sign. The current
has only two points of interruption. The letters are printed at equal distances
from each other. The paper advances regularly by its own mechanism. The
vacant space in the printing wheels affords time for the electro-magnet to be
demagnetized without any time being lost for that purpose. The apparatus
has always two printing wheels at disposal for telegraphic correspondence.
The
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe in conclusion that I-do-not-confine-or_restrict
myself to the precise details or arrangements which I have had occasion to
describe or refer to, as many variations may be made therefrom without
deviating from the principles or main features of the said Invention; but what
I consider to be novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent, is,―

page_text: First, the general construction and arrangement of electro-magnetic printing
telegraphs, as herein-before described.
Second, the peculiar construction and arrangement of key boards and
apparatus connected therewith, as herein-before described.
Third, the peculiar construction and arrangement of single printing
mechanism, as herein-before described.
Fourth, the peculiar construction and arrangement of double printing
apparatus, as herein-before described.
Fifth, the application and use of two successive electric currents for pro-
ducing each letter or sign, the intervals of time between such currents
being regulated by an escapement movement or other apparatus, moving
isochronously with similar apparatus at each of the receiving stations, as
herein-before described.
In witness whereof, I, the said John Henry Johnson, have hereunto
set my hand and seal, this Third day of November, One thousand
eight hundred and fifty-four.
J. HENRY JOHNSON. (L.S.)