IMPROVEMENTS IN PRINTING TELEGRAPHS
Year: 1872

page_text: LETTERS PATENT to Thomas Alva Edison, of Newark, in the State
of New Jersey, United States of America, for the Invention of
"IMPROVEMENTS IN PRINTING TELEGRAPHS.”
Sealed the 24th September 1872, and dated the 13th May 1872.
PROVISIONAL SPECIFICATION left by the said Thomas Alva Edison at
the Office of the Commissioners of Patents, with his Petition, on
the 18th May 1872.
I, Thomas Alva EDISON, of Newark, in the State of New Jersey,
United States of America, do hereby declare the nature of the said In-
vention for "IMPROVEMENTS IN PRINTING TELEGRAPHS," to be as follows:-
-
These improvements relate to the mechanism for moving the several
type wheels of different printing telegraphs in unison, and giving the
impression.
The type wheel is mounted upon a shaft, and revolved by a step-by-
step motion by a lever and armature acted upon by an electro-magnet,
the core of which is grooved upon one side longitudinally, which I find

page_text: is preferable in printing telegraphs, because greater speed can be
obtained.
Where two line wires are used, one to the type-wheel magnet, the
other to the printing magnet, the ratchet wheel of the step-by-step
movement has half as many teeth as there are types and spaces on the
type wheel, and one letter is printed on the open circuit and the next on
the closed circuit, and this type wheel is on a sleeve and moved by a
lever acted on by the printing lever. The type wheel can be turned
around the extent of one letter, so as to print the alternate letters that
had previously been out of position for printing. This same turning
movement of the type wheel on its shaft is sometimes communicated
by a V shaped wedge and holding dog, acted upon by the printing lever.
The type wheels are stopped at unison by the continued rotation of
the type wheel bringing an arm into the path of a stop on the type-
wheel shaft, and this is liberated by operating the printing lever.
In cases where the unison can be operated most conveniently by the
printing lever, it is effected by a wedge thereon acting against inclined
teeth on a wheel upon the type-wheel shaft. The absence of one tooth
in this wheel prevents the further action of the wedge at the unison
point.
The printing lever is provided with a weight that prevents it being
easily moved by the electro-magnet, but when moved its inertia effects
the impression. This can be used on one line wire instruments, the
impression being given after the type wheel is set by keeping the circuit
closed. An air cylinder with a piston also is employed to prevent the 2
printing lever moving, except by keeping the circuit closed a sufficient
time.
The paper is drawn along by a swinging claw or tooth pressed upon
the paper by a toggle or spring, and then moving with a swinging
segment or a roller, and a holding pawl keeps the paper from drawing 3
back.
Where two type wheels are used, and an end movement is given upon
the shaft to bring one into action and remove the other from action, the
said end movement is given either by an electro-magnet and polarized
armature that will be held in contact with the cores or repelled according 3
to the polarity of the current, or the printing may be from one type

page_text: wheel with an open circuit and from the other with a closed circuit, or
else the endwise movement is given from the printing lever by lever or
wedge acting connections operating upon radially slotted wheels.
It is to be understood that the printing instruments before described
are located at the places or stations distant from the sending or trans-
mitting station, and that they are operated by electric pulsations given
from the said transmitting station. I now describe the pulsator to be
used at said transmitting station to send these electric pulsations :-A
motor made of a shaft and armature revolved by stationary electro-
magnets gives motion by a friction clutch to a circuit breaker made of
alternate conducting and non-conducting material. The type wheel at
the distant station is moved around by these pulsations in unison with
a revolving arm at the transmitter (actuated by gearing from the pul-
sator), and when this arm is stopped by depressing one of a range of
finger keys the pulsator is stopped, also the type wheel, and the printing
circuit brought into action. The speed of the pulsator shaft is regulated
by a governor, that acts as a circuit breaker to the electro-magnets of the
motor, or "cuts out" those magnets by closing a shunt or more direct
circuit.
Where many printing telegraphs are worked in several circuits by one
transmitter or pulsator, it is often preferable to employ short relay
magnets with slotted cores and relay circuits between the transmitting
and printing instruments.
SPECIFICATION filed in pursuance of the conditions of the Letters
Patent, and of an Order of the Lord Chancellor, by the said
Thomas Alva Edison in the Great Seal Patent Office on the 15th
November 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
ALVA EDISON, of Newark, in the State of New Jersey, United States of
America, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of May, in the year of
our Lord One thousand eight hundred and seventy-two, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give

page_text: instruments, to the extent of hundreds, and in case of defect in any one
local circuit the other circuits will not be disarranged.
The third part of this Invention relates to the printing telegraph
instruments themselves, with the modifications in construction adapted
to various uses, and the appliances that are employed in or with such
instruments for effecting the various operations or for preventing diffi-
culties that may arise under different circumstances.
In the Drawings, Fig. 1 is a plan of the transmitter, and a diagram is
also shown representing the circuits to the relay magnets and printing
instruments, in which two wires are employed, one wire and circuit to
the type wheel magnets, the other to the printing magnets; in Fig. 2 a
diagram is shown of the transmitter and circuits to printing telegraph
instruments operated by one wire and electric circuit; and Fig. 3 repre-
sents the transmitting instrument by a vertical section.
The shaft a of the transmitting instrument is preferably revolved by -
magnetism. For this purpose two stationary magnets are used, one of
which a¹ is seen in Fig. 3, and there are three armatures 2, 2, 2; and
upon the shaft a is a circuit breaker 3 of alternate conducting and non-
conducting material that opens and closes the circuit to the magnets a¹
alternately, so as to attract the armatures successively and revolve the.
shaft a. The battery a' operates this motor, the wires being connected
at 4 to the bed b of the machine, and at 5 to the insulated binder, and
from that to the magnets a' and to the lever and roller 6 of the
respective pulsators, thence through the shaft a and bed 6 to 4. Upon
the shaft a are governor balls b' that rise by increased speed and bring
the flange 7 of the sliding sleeve into contact with the adjustable insu-
lated arm 18, Fig. 8, and the friction will check the speed, but it is
preferable to connect therewith a wire 95, so that the electricity will be
"short circuited," passing through 4, b, a, 7, 18, and 95 to 5 instead of
going through the electro-magnets a', thus lessening the power and the
speed and maintaining uniformity in the revolution of the motor.
If the governor balls act to connect a circuit through the magnets a¹, a',
the slight electro-magnetism remaining in the cores of the motor magnets
will act to detain the armature in revolving, and thereby lessen the
speed; and if the pin is below the flange 7, and the circuit to the motor
magnets passes that way, then the power will be checked when tho

page_text: maximum speed is attained by opening the circuit to said motor
magnets.
By a suitable connection such as the gearing 8, 9, 10, the shaft c is
revolved with the desired speed. It has two arms c', c³, on opposite
sides, one above the other, and these act in connection with two semi- 5
circular ranges of finger keys d, ď³. Beneath the bed 6 these finger keys
have arms d³, d³, converging towards the center of c, and when one of
the keys d is depressed its arm ³ stops the arm c³, shaft c, and
gears 8, 9, 10. The gear 8 is driven by friction, hence the motor and
shaft a continue to revolve, but connected with the gear 8 is a pulsator e 1
made of alternate conducting and non-conducting surfaces, and theso
open and close the circuits to the distant printing instruments or to the
relay magnets.
1
.
By bearing in mind that the parts are made so that the pulsator e
transmits the necessary number of pulsations to make a complete 18
revolution of the type wheels (at the distant instruments by a step-by-
step movement), each complete revolution of the shaft c, it will be
understood that the shaft c and the type wheels revolve in harmony, and
that when the shaft c is stopped by one of the keys d, or d³, the type.
wheels of the distant instruments are stopped, and the position of the 20
characters on the type wheels must be in harmony with the arrangement
of the keys d, ♫³, and when the key is liberated, the shaft c and pulsator e
resume their revolution and the distant type wheels also resume the
synchronous movement.
'
The printing telegraph machines illustrated at A, A, are operated by 25
two wires, those shown at B, B, Fig. 2, are operated by one wire; hence
with two wire instruments two ranges of relay magnets e¹, e¹, and e³, eª,
will be required, while only the range e¹ of relay magnets will be needed
with one wire instruments.
When two ranges of relay magnets are used, there are two rollers or 30
contact sprines 12 and 13. on insulated spring levers.
•
one is connected

page_text: The relay magnets will not respond, although the circuit is closed
by the roller 13, because the springs of the armatures of the electro-
magnets are under considerable tension, and the pulsator contact
points are small and send but a very short impulse, but when the
pulsator e is stopped by depressing one of the keys, the roller 12 rests
upon a non-conducting surface breaking the circuit through e', and the
roller 13 resting on a conductor closes the circuit through the relays e³,
causing them to close the circuits at 17 of the batteries e³, hence they
act in the distant instruments A. in the electro-magnets that effect tho
printing. The pulsatore when employed with the single range of relay
magnets e, as in Fig. 2, causes the pulsations to be repeated at 16
from the batteries e' to the distant instrument, and when the printing
is effected by a pause on a closed circuit the pulsator e is stopped with
the roller 12 in contact with the metallic portion of the pulsator, but if
the printing is effected by a pause upon an open circuit the roller 12 is
in contact with a non-conducting portion of the pulsator e.
I have shown the battery e³ in three sections connected with the
respective relay magnets and with three circuits, in each of which
circuits there may be any desired number of printing telegraph instru-
ments, and the circuits are completed through the ground connections.
The circuits to the transmitting instrument and the relay magnets
may be disconnected by a switch at es that may be turned around to
throw both batteries out of action, and the circuits from the batteries e*
will also be broken at the relay magnets.
It is preferable to employ slotted cores in the relay magnets and to
make these cores short, say not over two centimetres in length, and it is
preferable to employ a detached layer of wire around the outside of each
electro-magnet helix, which in practice will be found to lessen the sparks
at and the burning of the contact points without decreasing the power
of the electro-magnet. This extra layer or layers of wire should be put
upon the outside of each magnet in the printing instruments to lessen
the spark due to the discharge of the induced magnetism from the iron
cores.
-
The printing telegraph instruments and the appliances connected
with them form the third part of this Invention.
Figs. 5, 6, & 7 are vertical sections of the printing instruments;
Figs. 8 and 9 are elevations endwise of the printing lever; and Fig. 10

page_text: is a plan of the instrument. The base f of the instrument is of metal
with frames f¹ that support the type wheel shaft 9, upon which is the
type wheel or wheels (, ) and the electro-magnet is employed to
move a lever A³, and by a step-by-step movement from pawls or wedge-
acting teeth i operating upon a toothed wheel k the type wheel will be
moved around progressively by the electrical pulsations aforesaid acting
in the magnet h.
The electro-magnet m actuates the printing lever m² to give the
impression, and this electro-magnet m is energized when the type wheel
has been turned, and the proper letter or character brought into position
for printing.
n
The arms 20 extend up sufficiently to carry a reel with the strip of
paper, and the types on the wheel are inked by a roller 21. A spring 22,
Figs. 5 & 8, may be used to press the ink roller upon the types.
Wherever the before described parts are shown in the various figures
the same letters of reference are applied.
The magnets m and h are adjustable vertically by screws 23, 24, that
pass through the bed and act upon the cross bars carrying the magnets,
and the soft iron cores of the electro-magnets are by preference made
with a longitudinal slot, as seen in Fig. 4, so that the residual magnetism
will be freely discharged, and the helix are preferable when made of fine
wire without insulating covering wound by machinery, and with a layer
of paper between one layer of wire and the next. The line wires
of the electric circuits are connected with the binding screws 26 for
the magnet h, and with the binders 27 for the magnet m.
The improvements in the printing instrument divide themselves into
the following features:—
First. Means for printing from one of two type wheels while the
other type wheel is not being printed from.
Second. Means for bringing all the type wheels in the various printing :
instruments into unison by turning them around to a unison or stopping
point and then liberating them all at once, so that all start together, and
thus errors in printing are avoided.
Jn
Third. Means for moving the strip of paper along. The type wheels
Biog 7 0 and 10 Ara 115An л cleane 42-4

page_text: shaft g; to this is connected a T lever o³, and upon the printing lever
m are two stops or pins 30 & 31, positioned so that when the
type wheels are stopped at one point and the printing lever is moved,
the pin 30 taking one end of the lever o¹ will shift the type wheels in
one direction, and if turned around another notch (of %), the other pin
will act on o', as the printing lever is moved, and shift the type wheels
the other way. Upon the printing lever m² is a shield o' of thin metal
under which the strip of paper passes and in which shield is in an opening
so that one type wheel will print through the opening, the other being
kept from touching the paper; there is a printing pad p' on the printing
lever below the paper at this point.
The person at the transmitting station brings either type wheel into
action by stopping all the type wheels at the proper position and
allowing the printing lever to be moved by closing the circuit through
the printing magnet. As there are but two points where the change
can be made either one way or the other, a disk p is used on the type
wheel sleeve or shaft with a notch, and the cam p' is on either one side
or the other of the disk, so that the parts cannot shake out of place.
The type wheels may be shifted endwise by a magnet 9 and lever q¹,
see Fig 11, acting on the sliding sleeve o. In this case the electric
circuit passes through the magnet h, then through the magnet q and the
toothed wheel k, on the type wheel shaft, g is to be of the character
shown in Fig 7, so that the rotation of g will be half a space (of k),
as the lever h³ is attracted by h, and the other half space as the lever /¹
is drawn back by its spring. If therefore the circuit is kept closed
through and q, the type wheel will be held in position to be printed
from, but if the printing circuit through m is closed when the electric
circuit through h, q, is broken, then the wheel A will be in position for
being printed from, the spring g³ moving the type wheels to the left, Fig
11. The types on 1, 4, in this instance must be positioned so that the
type on one wheel is in line with the space between two types on the
other wheel.
If the armature g³ of the magnet q is permanently magnetized, then it
will either be attracted or repelled, according to the polarity of the
electric current passing through q, therefore by this modification ono
type wheel will be brought to position for printing by a positive current
and the other by a negative current. The same is the case with the

page_text: types on the wheels shown in Figs. 12, 14, but in these Figures the
shifting is accomplished mechanically instead of electrically by lovers or
inclines r,, moved by the printing lever m², and acting against tho
notched wheels. These parts are positioned so that with a closed
electric circuit the lever or incline will press against the side of the
wheel,ª and shift the type wheels to the left to print from the wheel 1,
and the lever or incline ³ will not be operative because it will pass into
the notch in ³, as shown in Figs 13 & 15, but when the printing lever
m² is moved with the electric circuit through open, the lever or incline
will operate on ³, and shift the type wheels the other way, and bring
the type wheel into position for printing from.
h
Where the characters on the type wheels are positioned in two rows as
in Fig 16, with the characters in one row opposite the spaces in the
other row, it is necessary that the type wheel should be turned around
upon its axis a distanco equal to half a space to bring one row of
characters in position for being printed from, and the other row where
there will not be any impression on account of the spaces between the
types.coming over the impression pad. I accomplish this by a T headed
spring bolts that enters one of two notches on an arm 35, that extends
from the sleeve of the type wheel. When this bolts is raised as in Fig
18 by the impression lever m² the type wheel and arm 35 can be turned
by a wedge tooth o³ on the lever m³, acting against one of the inclined
faces of the arm 36. If the type wheel is to be moved the other way
half a space the type wheel is rotated further around so that the wedge
tooth &³ acts the other way on the opposite face of the incline 36.
When the printing lever recedes, as in Fig. 17, the T head of the bolt
8 holds the type wheel in place by falling into the appropriate notch
in 35. A similar movement is given to the type wheel by the device
shown in Fig. 8, wherein the lever o' shifts the cam 36 and turns the
type wheel partially around upon its axis; in this case the movement
may either be an entire letter space so as to print from alternate letters
or characters, one set of characters being in position for impression
when shifted one way, and the intermediate letters or characters being
in position for printing when shifted the other way.
Figs. 19 and 20 are plan views of the machines in which the two
type wheels are employed as before; but instead of moving the type
wheels, the printing levers are made in two parts, with separate im-

page_text: pression pads, as seen in Fig. 21, and notched wheels 7³, ³, are attached
upon the shaft g instead of the sleeves o, as in Figs. 12 & 14, and
although both the printing magnets m, m², are energized only one
printing lever m³ can move because the finger rises in the notch
of the wheel ³, see Figs 19, 21, and 22, and the other lever m¹ is
stopped from rising because its finger - comes in contact with the
projection or tooth of the notched wheel, thus one type wheel Z
will be printed from on the open circuit (through h), and the other
wheel A will be printed from when the circuit through his closed.
In Fig. 20 the separate impression pads and levers are controled
electrically instead of mechanically. In this case the arm 45 on the
axis of the type wheel lever closes the circuit, as seen in Fig. 23, to
the magnet m when the magnet is energized, and on the open
circuit of the magnet, the said arm 45 will close the circuit through
the magnet m', and thereby an impression will be taken when the type
wheels stop rotating from either the wheel 1 or A, according to whether
the wheels are stopped on an open or a closed circuit through h.
It is to be understood that the pulsations in h and the vibrations of 45
are too rapid to allow either magnet m or m³ to be energized until a
pause takes place and the type wheels stop.
In instruments where there is but one wire passing through both the
printing magnet m and the type wheel magnet h, as seen in the small
inverted plan, 24, there will be a movement of the printing lever
each pulsation that is sent for setting the type wheel if there is not a
resistance to the movement of the printing lever that cheeks that move-
ment during the ordinary pulsations; but that resistance is overcome
during a pause sufficient for developing the full power of the printing
magnet. This resistance to the movement of the printing lever may be
a spring, but the weight m³, Figs. 7, 9, and 24, is preferable, as it
prevents by its inertia a sudden movement, and when in motion the
inertia aids the power of the electro-magnet in striking the pad against
the paper with a sufficient blow to make a good impression.
In Fig. 25 this resistance to the movement of the printing lever is
obtained by employing an air cylinder and piston, the latter being con-
nected to the lever m³ by a rod m. In this case the pulsations in the
magnet operate to set the type wheel or by a step-by-step move-
ment; but they do not move the impression lever m² sufficiently for

page_text: printing because the spring m" is acting upon the same, and the air
cushion in the cylinder formed between the piston and the cylinder
arrests any sudden movement, and the spring m¹³ acts between the
pulsations to keep the piston from gradually forcing the air out of the
cylinder; but when the circuit is kept closed at the transmitting station
the printing lever is allowed to move and give the impression, as the
rod m³ moves the piston and displaces the air cushion sufficiently to
allow of this movement. The piston may have a valve to open as the
lever descends so as to allow the printing pad to move rapidly away
from the type wheel.
The next feature of this Invention relates to an automatic device for
bringing all the type wheels to a unison or harmonious starting point.
Ordinarily it is not necessary to rotate the type wheels more than two
revolutions before the required letter will be in position for printing.
The unison is brought into action by giving to the type wheels two
or more revolutions, and in the act of so doing bringing into action
a stop that arrests the further movement of the type wheel, but the
pulsations are continued sufficiently to bring up to that stop any
type wheels that may be out of unison, and then upon operating the
printing lever a movement is given to the unison stop that liberates
the type wheels all at once, and they are then in position for starting
again in unison. The most convenient unison is an arm of with the
end in a screw thread o³ on the shaft g, and a pin 50 that stops
against the end of that arm, and when the printing lever m² is moved
the arm o 'is lifted out of the screw o' by the forked bar 53, and a
spring 51, Figs. 9 & 10, returns it to a normal position. The pin 50
may be in the side of a disk, and a volute groove in the disk take the
place of a screw.
In Figs 5 & 8 an arm o' is shown on the type wheel shaft g, taking
in succession the teeth 54 on the arm o³, and drawing it down into the
path of 50, the stop o' is lifted by the bar 53, as before, when the
printing lever is moved.
In instances where the type wheel is moved half a space on closing
the circuit and the printing takes place on an open circuit, a unison
wheel can be employed, such as shown in Figs. 6 and 26. In this
instance the magnet h draws down the pallets ; and holds the ratchet
wheel and the separate ratchet wheel ' in the position shown in Fig. 26,

page_text: so that the point 60 on the printing lever m³ will act as a wedge and
force around the type wheel 2, and the wheels and one tooth at a
time, as the printing lever is moved by the magnet m, but when the
space (made by removing one tooth in the wheel **, Fig. 26) arrives
at the point 60 the turning of the type wheel will cease because there
is nothing for the point 60 to act against.
The printing pad p" may be a small rubber or elastic roller, so as to
turn and present different sides to the impression.
To move the paper along a pawl u is employed and a roller or
segment . As the impression lever is raised the pawl u is forced upon
the paper, holds the same, and feeds the strip along the required
distance.
The lever o³, Figs. 7, 9, and 10 is moved by a pin on the printing
lever in a slot in the lever o³, and a holding pawl w, Figs. 9 and 10, acts
to prevent the paper drawing back.
In Fig. 5 the pawl & has an arm that is connected by a link 68
to the printing lever m³, so that as the lever rises the paper is first
caught by the pawl u, and then the parts move together as the lever ø²
is swung by the link 62; there is a slight looseness in the joint of the
link 62 that allows the pawl u to be pressed upon the paper before the
other parts move. The pawl may be made to slide and move the paper
along in a shallow trough, and the end of the sliding pawl, coming;
against a stop as the printing lever and pawl are moved, gives the feed
motion to the paper.
What I claim as my Invention and desire to secure by Letters Patent

page_text: Thirteenth. The cam 36 moved by the T lever o' and pins 30, 31, upɔn
the printing lever, in combination with the type wheel and sleeve o,
substantially as and for the purposes set forth.
Fourteenth. The wheels,, Figs. 19, 22, projections r, r, and
levers m³, m, in combination with the type wheels 1,, substantially as
set forth.
Fifteenth. Two separate printing levers and their respective magnets
in the same or branch circuits, in combination with two type wheels
positioned as specified, and mechanism substantially as set forth, for
preventing an impression from one of the type wheels while the other
is being printed from, substantially as set forth.
Sixteenth. The circuit closing arm 45, Figs. 20, 23, and connections
to the respective magnets m, m², in combination with the printing
levers m², m", type wheels 2, A, and actuating mechanism, substantially
as set forth.
Seventeenth. The printing lever and weight m³ in combination with
the type wheel and an electro-magnet, for the purposes and as set forth.
Eighteenth. The combination in one electric circuit of two or more
type wheel magnets, and two or more printing magnets, and two or
more weighted printing levers, substantially as set forth, whereby the
printing will be effected by the same pulsation used to bring the type
wheel to place, but only when the printing magnet has accumulated
sufficient force to give a blow by the weighted printed levers, sub-
stantially as set forth.
Nineteenth. The air cushion, Fig. 25, applied to and combined with
the printing lever and its magnet in a printing telegraph instrument, in
the manner and for the purposes specified.
Twentieth. The arm o' and stop 50 upon the shaft g in combination
with the arm o‘, teeth 54, and forked bar 53, moved by the printing
lever m³, the parts being arranged and operating, substantially as set
forth.
Twenty-first. The wheel and tooth 60, actuated by the printing
lever m'in combination with the type wheel 2, wheel k, and pallets i,
substantially as and for the purposes set forth.
Twenty-second. Adjusting the type wheel to the unison point by the
movement of the printing lever, while the type wheel pallets are in the

page_text: opposite, position to that which they occupy when the type wheel is
being printed from, substantially as set forth.
Twenty-third. The pawl upon the arm', connected by the link 69
with the lever m³ in combination with the slotted link 62, that swings
the lever o' to feed the paper, substantially as specified.
Twenty-fourth. The spring 22, attached to the paper reel arms 20,
and capable of being swung aside, in combination with the inking
roller 21, sustained by arms from the cross bar a³, as set forth.
Twenty-fifth. The electro-magnets, provided with slotted cores, and
applied to a printing telegraph instrument, substantially as and for the
purposes set forth.
In witness whereof, I, the said Thomas Alva Edison, have here-
unto set my hand and seal, this 21st day of October, A.D. 1872.
Witnesses,
THOMAS A. EDISON. (L.S.)
OHA*. E. SMTE, 121, Nassau St., New York, N.Y.
HAROLD SERRELL,
"