IMPROVEMENTS IN THE TRANSMITTING AND RECEIVING PROVISIONAL SPECIFICATION
Year: 1880

page_text: LETTERS PATENT to Henry Van Hoevenbergh, of 135, Broadway, New York,
United States of America, and of Ludgate Circus, in the City of London,
for an Invention of "IMPROVEMENTS IN THE TRANSMITTING AND RECEIVING
PROVISIONAL SPECIFICATION left by the said Henry Van Hoevenbergh at
the Office of the Commissioners of Patents on the 10th December 1880.
HENRY VAN HOEVENBERGH, of 135, Broadway, New York, United States of
America, and of Ludgate Circus, in the City of London. "IMPROVEMENTS IN
THE TRANSMITTING AND RECEIVING APPARATUS OF PRINTING TELEGRAPHS."
This Invention has for its object improvements in the transmitting and receiving
apparatus of printing telegraphs.
My Invention relates especially to that class of printing telegraphs which are
designed to be operated automatically by means of electric pulsations proceeding
from a suitable transmitter situated at a point more or less distant. The general
object of the Invention is to increase the rapidity and certainty of operation of
such an apparatus, and to provide improved means of maintaining the synchronism
between the transmitting cylinder at the sending station and the type wheel at
the receiving station or stations, by causing the same to be regulated or adjusted
automatically once during each revolution, instead of at irregular intervals and
at the will of the transmitting operator, as in the apparatus beretofore in
general use.
The receiving apparatus which I will first describe may be said to consist of
three sets of mechanism, the first of which produces and controls the intermittent
rotation of the type-wheel, the second produces the impression of the proper letter
upon the paper and moves the paper forward to the type wheel as required, and
the third controls the synchronism of the type wheel with the transmitting
apparatus at the distant station, and restores the same to its proper position or
relation when it is thrown out of correspondence by accident or otherwise.
The type wheel is mounted upon an arbor, to which is also fixed a scape-wheel.
The type wheel and scape wheel tend to rotate continuously impelled by a train of

page_text: wheel work. The type-wheel is held in check by an anchor escapement, whose
pallets engage alternately with opposite teeth of the scape-wheel. The escapement
is fixed to a rock shaft from which projects an arm carrying an armature.
Two electro-magnets are arranged with their poles facing towards each other
upon opposite sides of the armature. The yoke or back armature of each of these
electro-magnets, instead of being made of soft iron in the usual manner, consists of
a permanent steel magnet of horse-shoe shape, into the opposite poles of which the
respective cores of the electro-magnets are firmly screwed or otherwise secured.
The permanent magnet induces corresponding polarity in the soft iron cores
attached to its poles, and thus they are rendered in effect permanently magnetic,
but of opposite polarity.
I prefer to arrange the electro-magnets with their similar poles facing each other,
in which case the armature being a neutral piece of soft-iron will be attracted
indifferently by either pair of cores when no current passing. The helices or
coils are so arranged that the direction of the current through them in reference to
the normal magnetism of the cores will produce an opposite effect in the two
electro-magnets, and strengthen the normal magnetism of the one, and partially or
wholly neutralize that of the other. Thus by transmitting alternate pulsations of
positive and negative electricity through both electro-magnets (these being
included in the same circuit) the armature may be made to vibrate to and fro
with great rapidity.
The printing mechanism consists of a lever fixed upon an arbor or shaft, which
carries a cylindrical pad or platen and a paper feeding mechanism of the usual con-
struction, by means of which a paper, ribbon, or tape is drawn forward to receive
the impression of the succesive characters as required. An electro-magnet actuates
the printing lever by direct action upon its armature, which is attached to the axis
of the printing lever by means of an adjustable device. The armature is mounted
upon an arm loose upon the shaft and having a downward projection.
Parallel to this latter is another arm which is rigidly attached to the axis. The
arms may be adjusted towards or from each other by means of screws.
The printing magnet is included in the same circuit with the magnets which
control the movement of the type-wheel, and is actuated when required simply by
increasing the strength of the current by which the final movement of the type-
wheel was effected, the ordinary pulsations which are of sufficient strength to
operate the type-wheel armature being altogether insufficient to actuate the
printing devices.
The unison mechanism consists of a detent affixed to one end of a rock-shaft, and
which by means of an adjustable spring is normally held in a position directly in
the path of a pin or stop which is inserted into the type-wheel and revolves with
it. When the pin in its revolution comes in contact with the end of the detent,
the type-wheel is arrested at the zero or starting point and there held, notwith-
standing the action of the escapement and wheel-work, until the detent is
withdrawn. If the type-wheel is moving in unison with the transmitting
cylinder, a pulsation of considerably more than the normal strength of current,
which is sent through the line by the transmitter at the moment of passing the zero
point, withdraws the detent or stop and allows the pin to pass by, consequently
the progressive movement of the type-wheel is not arrested; but in case the
type-wheel is thrown out of correspondence with the transmitter by reason of any
disarrangement of the conductors or the mechanism, or other cause, so as to fall one
or more steps behind the transmitter, the pin will not reach the stop in time to
pass by it at the moment of its withdrawal, and the type-wheel will therefore be
arrested and held by the detent until the latter is withdrawn by the action of the
transmitter in the next succeeding revolution, when the type-wheel will necessarily
start in unison with the transmitter. Thus the position of the type-wheel is
automatically corrected if found wrong upon reaching the zero point in each
revolution.
The withdrawal of the detent from the path of the pin is effected by a device

page_text: which will now be described. The motion in each direction of the armature, which
carries with it the escapement, is limited by a pendulum arm which is fixed upon
the same axis and vibrates between two adjustable stops. One stop is secured
permanently to the frame of the instrument, but the other is mounted upon a short
arm secured to the rock shaft which carries the detent.
The tension of the detent spring is sufficient to hold the moveable stop in
position, except when a pulsation of increased strength is sent, when the tension
of the spring is overcome and the stop yields slightly, falling back against a
stationary block, and at the same time withdrawing the detent from the path of
the pin on the type-wheel.
The pendulum arm although rigidly attached to the axis of the escapement is
not in itself entirely rigid, but is preferably constructed of steel and of such a
thickness as to be capable of bending slightly under the force exerted upon it by
the armature after it comes in contact with one or the other of the stops. This
construction gives the arm a certain degree of resiliency, by virtue of which when
the armature is released by the electro-magnet on either side the recoil of the arm
aids materially in accellerating the movements of the armature towards the opposite
electro-magnet, and greatly enhances the rapidity of vibration which it is
possible to impart to the armature by the alternate action of the electro-magnets.
As the printing mechanism, as well as the mechanism for correcting the type-
wheel, are both set in action by a pulsation of increased strength, it is necessary
to make provision for preventing the impression device from operating whenever a
pulsation is sent forth for the purpose of withdrawing the unison stop. This is
effected by means of a rotating contact-point upon the type wheel, which touches
an insulated spring during each revolution at the instant the pin is passing the
unison stop. This closes a shunt circuit around the printing magnet, and momentarily
cuts it out of circuit while the unison device is being operated, and thus prevents
the printing mechanism from operating. Another important function of this
circuit-closer and shunt is that it reduces the resistance of the main circuit by the
amount of the resistance of the printing magnet, and to that extent increases the
strength of the current in the line at the moment the unison mechanism is to be
operated. This in many cases is sufficient to effect the release of the unison-stop
without the employment of additional cells of battery at the transmitting station
for this purpose.
Thus it will be understood that the three principal working parts of the apparatus
are operated by three different strengths of current. The normal strength of
current, which is also the weakest, is sufficient to actuate the escapement controlling
the type wheel by reversals of polarity, but not sufficient to effect the printing, or
to withdraw the unison-stop. A certain additional strength is sufficient to effect
the printing also, but not to withdraw the unison-stop, which can only be done by
the aid of a still stronger current, and this last is prevented from operating the
printing-magnet by the shunting device hereinbefore described.
The action of the printing and unison devices is of course wholly independent of
the polarity of the current.
I will now proceed to describe the transmitting apparatus.
The complete transmitting apparatus may conveniently be regarded as composed
of three divisions, the first of which controls the transmission of the positive and
negative pulsations by which the intermittent rotation of the type wheel of the
receiving instrument is effected, the second produces the impression of the required
character after the type wheel has been brought into position, and the third
controls synchronism of the type wheel at the receiving station and keeps it in
correspondence with the transmitting cylinder at the sending station.
The first part of the apparatus consists of the cylinder mounted upon a driving
shaft which is driven by a pulley, the connection between the pulley and the
shaft being effected through the agency of a peculiar clutch, the construction and
operation of which will hereinafter be more particularly described. The cylinder
s placed directly beneath the key board, which may be constructed of any required

page_text: number of keys somewhat similar to those of a piano or other musical
instrument.
Two spiral rows of metallic pins or stops are inserted in the cylinder. Upon
the under side of each key is a pin or stud, which when the key is depressed
projects into the path of the corresponding pin or stop upon the cylinder, and thus 5
arrests its forward motion. It will be understood therefore that each one of the
series of keys when depressed will arrest the motion of the cylinder at a determinate
point in its revolution. So long as none of the keys are depressed the cylinder
turns with a continuous and uniform motion, being driven by any suitable or
convenient source of power.
In order to disconnect the cylinder from the pulley whenever the former is
arrested by the depression of one of the keys I make use of an electro-magnetic
clutch, the construction and operation of which will now be explained.
A disc or plate of soft iron is rigidly fixed to the axis of the cylinder, and
revolves with it. An electro magnet, preferably having four poles together, with
the driving pulley is rigidly attached to a shaft, which turns in suitable bearings
in line with the shaft upon which the cylinder is mounted. The electro magnet is
so adjusted that its four poles revolve in contact with the plane surface of the soft
iron plate or disc. The effect of this arrangement is, that when the electro magnet
is rendered powerfully magnetic, the attraction exerted by it upon the soft iron
disc is so great, that the latter together with the shaft is compelled to revolve with
it, and by this means the motion of the revolving electro magnet is communicated
to the shaft and cylinder. The disconnection takes place instantly upon the
demagntization of the electro magnet. The cylinder, which is preferably composed
of non conducting material, such as hard rubber, is not attached rigidly to the shaft
upon which it is mounted. The mechanical connection between the cylinder and
shaft is a yielding one, and consists of a spiral spring, one end of which is attached
to a hook inserted in the end of the cylinder, while the other end is attached to an
arm rigidly attached to the shaft. At the opposite end of the shaft is another
similar arm, which by virtue of the tension of the spring normally rests against an
arm projecting from the cylinder.
These arms are provided with electrical contact points. When these points are
pressed together an electrical circuit from a local battery traverses the coils of the
electro magnet.
It will therefore be understood that when the cylinder revolves freely, the arms
will be maintained in contact with each other by the action of the spring, and that
the current of the local battery will traverse the coils of the electro magnet and
keep the same constantly magnetized, thereby coupling the pulley to the cylinder,
but if one of the keys is depressed by the operator the cylinder is arrested while
the shaft moves forward, and thus breaks the local circuit, which instantly
demagnetizes the electro magnet. The latter, however, continues to revolve freely
with the driving pulley. A ratchet wheel provided with a spring click serves to
prevent any retrograde movement of the shaft after the cylinder has been arrested
by the depression of the key and the motor shaft disconnected. When the key
is released by the operator the cylinder is left free to revolve, the local circuit
between is again closed, and the apparatus moves forward as before until arrested
in a similar manner by the depression of some other key.
In order to actuate the escapement which controls the movements of the type
wheel of the receiving instrument, it is necessary, that say, thirty six electrical
pulsations should be transmitted over the lines during each complete revolution of
the cylinder. These pulsations are transmitted alternately from the positive and
negative poles of the battery by means of a commutator of peculiar construction,
which is termed a pole-changer, and consisting of a rocking shaft upon which is
fixed a piece of hard rubber or like insulating material. In this are inserted four
metallic pins. Upon these pins rest two metallic springs, and each spring as the shaft
rocks bears first on one pin and then on the other of the two pins beneath it.
The springs are connected with a battery, and the pins with the line and earth.
1

page_text: Thus it will be understood that if the shaft be caused to oscillate or rock
backwards and forwards, alternate positive and negative pulsation from the battery
will be transmitted over the line. In practice, any required number of separate
and independent lines may be operated from one key board and transmitter
by making use of as many separate commutators or pole changers as there are
single lines to be operated, and mounting them all upon a single shaft.
All the four contact points are upon the upper surface of the insulating block
which supports them; and by this mode of construction a very important advantage
is gained, inasmuch as the adjustment of the contact points with reference to each
other and to the contact springs which work upon them is much more easily
performed, for the reason that all four of the contacts are visible to the eye and
are conveniently accessible at the same time.
The oscillation of the rock shaft is effected by means of the hereinafter described
mechanism :-
Upon the end of the shaft which carries the cylinder is fixed a wheel, having
its periphery formed into alternate recesses and projections of a wave like form.
Directly above and in the same plane with this wheel is mounted another precisely
similar wheel.
The number of projections and recesses upon each of these wheels, taken together,
is equal to the number of pins upon the cylinder, and also to the number of
characters and spaces upon the type wheel of the receiving instrument. The
wheels are connected to each other by means of toothed wheels, having each a like
number of teeth. The wheels are so mounted with reference to each other that
the projections of one wheel are precisely opposite to the recesses of the other. The
space between the wheels is just sufficient to admit a pin, which is inserted in the
arm of a right angled or bell cranked lever, the other arm of which is connected by
a rod with an arm fixed upon a rock shaft.
It will be understood therefore that as the wheels revolves an oscillatory motion
will be communicated to the rock shaft upon which the pole changers are mounted.
The amplitude of the oscillations of the pole changers is capable of being adjusted
within the necessary limits by lengthening and shortening the vertical arm of the
bell crank lever, which is made in two parts clamped together by screws, in order
to facilitate such adjustment.
In order to render the mechanism beneath the key board conveniently accessible
for purposes of inspection, repairs, or adjustment, I have mounted the key board in
such a manner that it may readily be turned back out of the way when necessary.
Each of the keys is attached to a flat spring extending rearward therefrom, and
secured by screws or otherwise to a longitudinal wooden support. This support is
secured to the base upon which it rests at its lower rear corner by hinges, and is
preferably held in position by a moveable catch. By this arrangement the operator
is enabled to turn the key board and its support backwards, and thus to obtain
ready and convenient access to the mechanism beneath. The cover which protects
the mechanism in front is hinged in a like manner so as to be capable of being
turned forward out of the way.
Another part of the mechanism has the office of bringing the printing mechanism
of the receiving instrument into action, which is effected by augmenting the normal
strength of the actuating current after the type wheel has been brought into
position without reference to the polarity of the final pulsation, whether positive or
negative.
The
An electro-magnet of the usual construction provided with an armature and
lever is interposed between the sending battery and the pole changer.
armature lever oscillates between contact stops, the whole, in fact, constituting a
relay of the ordinary and well known construction, with the exception that the
lever makes electrical contact with its rear stop as well as with its front stop. The
coil of this electro magnet is included in the circuit of the local battery, which
controls the electro magnetic clutch herein before described. The armature lever
of the relay magnet, when in contact with its front stop, brings but half of the

page_text: battery into circuit, but when it rests against its back contact the whole of the
battery is on. It will be readily understood therefore that when the circuit of the
local battery is broken (and this occurs each time that the motion of the cylinder
is arrested by the depression of the key) the armature lever falls on its back
contact, thus momentarily throwing the current of the whole battery upon the
main line during the time of the pause in the movement of the cylinder, as herein
before described.
The unison mechanism in the receiving instrument is controlled by single
pulsations of considerably more than the normal strength of the current which is
required to effect the printing, which pulsations are sent through the line by the
transmitter at the instant of passing the zero point in each revolution of the
cylinder and its corresponding type wheel. I prefer to effect this by short circuiting
or shunting an artificial resistance placed in the main line circuit. This shunt
circuit is closed by a contact point and metallic spring. Whenever the spring
touches the contact point the resistance is cut out and the strength of the current
on the main line thereby augmented. This is effected momentarily once in each
revolution at the required point by means of a pin on the cylinder which engages
with a cam shaped projection on the spring, and thus throws the latter momentarily
into contact with the point.
When the transmitting apparatus is at rest and in readiness to commence the
transmission of a message of communication it is necessary that the cylinder should
always stand at the zero point. I therefore provide a small right angled lever or
cam having a suitable handle which is pivotted to the frame of the instrument
just above the zero key at the extreme left of the key board. When the handle is
in an horizontal position, the short end of the lever presses against a cam shaped
projection on the upper surface of the zero key, and thus depress it so that the type
wheel is arrested by the action of the zero key in the usual manner. When it is
desired to commence the transmission of a communication, a slight touch of the
operator's finger upon the zero key frees it.
It is obvious that numerous changes may be made in the arrangement of the
circuits at the transmitting station, by means of which the required results are
produced at the receiving station. For example, the increase of strength which is
required to actuate the printing mechanism might be obtained by shunting a
normal resistance instead of making use of an auxiliary battery. On the other
hand, an auxiliary battery might be employed to actuate the unison mechanism
instead of the devices which I have described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Henry Van Hoevenbergh in the Great Seal Patent Office on the
10th June 1881.
HENRY VAN HOEVENBERGH, of 135, Broadway, New York, United States of
America, and of Ludgate Circus, in the City of London. "IMPROVEMENTS IN
THE TRANSMITTING AND RECEIVING APPARATUS OF PRINTING TELEGRAPHS."
This Invention has for its object improvements in the transmitting and receiving
apparatus of printing telegraphs.
My Invention relates especially to that class of printing telegraphs which are
designed to be operated automatically by means of electric pulsations proceeding
from a suitable transmitter situated at a point more or less distant. The general
object of the Invention is to increase the rapidity and certainty of operation of
such an apparatus, and to provide improved means of maintaining the synchronism
between the transmitting cylinder at the sending station and the type wheel at
the receiving station or stations, by causing the same to be regulated or adjusted
automatically once during each revolution, instead of at irregular intervals and at
the will of the transmitting operator, as in the apparatus heretofore in general
use.
To this end my improvements in receiving apparatus consist,-
First. In controlling the type wheel by a non-polarized armature common to
two or more electro-magnets, each of which electro-magnets has its two cores
normally polarized oppositely to each other by a permanent magnet, these electro-
magnets being arranged with poles respectively facing each other upon opposite
sides of said armature in combination with coils or helices upon the cores of said
electro-magnets, which are connected together in the same circuit in such a manner
that a positive current traversing them tends to neutralize the normal magnetism
of the electro-magnet on one side of the armature, and to increase that of the
electro-magnet on the other side thereof, while a negative current will tend to
reverse the said action, whereby the to and fro vibration of a non-polarized
armature is effected by alternate electric pulsations.
Second. In making use of an electro-magnet or magnets for controlling the
movement of the type wheel, together with an independent electro-magnet in the same
circuit for controlling the impression device in combination with a shunt or branch
circuit around the impression magnet, which is momentarily closed at a given point
once in each revolution of the type wheel by a device moving synchronously with
the type wheel, whereby the unison device may be operated by means of an
increased current without effecting the printing mechanisın.
Third. In the combination of a type wheel, an electro-magnet or magnets for
controlling the same, and a unison stop which automatically locks the type wheel
at the zero point, and releases it by the action of the said electro-magnet when
traversed by a current of increased strength, whereby the said unison-stop may be
operated from the type wheel magnet.
Fourth. In the combination of an electro-magnet or magnets for controlling the
movements of a type wheel with a yielding stop, which limits the arc of vibration
of the armature of said electro-magnet, so long as the said armature is under the
influence of a normal current, and a unison stop upon the type wheel, which is
controlled through the said yielding stop by varying the normal strength of current
traversing the type wheel magnets.
Fifth. In the combination of an electro-magnet or magnets for controlling the
movements of a type wheel, a yielding stop which limits the arc of vibration of the
armature of said electro-magnet or magnets, when under the influence of a current

page_text: of normal strength, with a unison detent or stop normally resting in the path of
the type wheel and adapted to arrest the same at the zero point, and a connection
from said yielding stop to the unison detent, which withdraws the same and releases
the type wheel whenever the normal strength of current through the type wheel
magnet is increased.
Sixth. In the combination of a rotating type wheel a unison stop arranged to
arrest the rotation of said type wheel at the zero point, and electro-magnet which
withdraws said stop and releases the type wheel when the normal strength of the
current traversing its coils is increased, with a circuit closer revolving synchronously
with said type wheel, and a unison stop acting to momentarily increase the strength
of the current in said electro-magnet simultaneously with the arrest of the type
wheel by the unison stop, whereby the cutting out of the resistance of the printing
magnet assists in strengthening the current for operating the unison mechanism.
Seventh. In the combination of a type wheel, an electro-magnet or magnets, an
armature, a yielding stop for limiting the arc of vibration of said armature, and a
rock shaft, upon which the said yielding shaft and unison detent are mounted.
Eighth. In the combination with a type wheel of a movable impression lever
constructed in two parts, the platen being mounted upon one part and the armature
of the actuating electro-magnet upon the other, and an adjustable joint or con-
nection between the two parts of the lever.
Ninth. In combination of a vibrating armature actuated by one or more electro-
magnets, a resilient arm having one of its ends rigidly secured to the axis of said
armature, and stops which limits the vibrations of the free end of said resilient arm
in each direction, whereby the recoil of said arm is utilized to enhance the
rapidity of the vibrations of the type wheel.
In the accompanying Drawings Figure 1 is a front elevation of a printing tele-
graph instrument embodying my improvements; Figure 2 is a vertical transverse
section of the same; Figure 3 is a detached view in elevation of a portion of the
mechanism; Figure 4 is a skeleton view, illustrating the electrical connections of
the apparatus; and Figure 5 is a detached view in the perspective of certain details
of the mechanism; Figure 6 shews a modification of the unison mechanism.
The complete apparatus may be said to consist of three sets of mechanism, the
first of which produces and controls the intermittent rotation of the type wheel,
the second produces the impression of the proper letter upon the paper, and moves
the paper forward to the type wheel as required, and the third controls the
synchronism of the type wheel with the transmitting apparatus at the distant
station, and restores the same to its proper position or relation when it is thrown
out of correspondence by accident or otherwise.
The first part of the apparatus consists of a type wheel A having any required
letters, figures, or other characters engraved upon its periphery. The type wheel
is mounted upon an arbor a, to which is also fixed a scape wheel B. The type
wheel and scape wheel tend to rotate continuously in the direction of the arrow in
Figure 1, impelled by a train of wheel-work C, Č, which receives its motion from
the barrel c and cord c¹, to which a weight is attached, and which may be wound
up as required by applying a key to the post c". The type wheel is held in check
by an anchor escapement D, whose pallets engage alternately with opposite teeth
of the scape wheel B. The escapement D is fixed to a rock shaft d, from which
projects an arm e carrying an armature E.
The herein before described mechanism is old and well known, and by itself
forms no part of my Invention, but I make use of a novel construction and arrange-
ment of electro-magnets for producing the vibration of the armature E, by which
the step by step advance of the type wheel A is produced through the agency of
the escapement B.
Two electro-magnets F and F¹ are arranged with their poles facing towards each
other upon opposite sides of the armature E, as best seen in Figures 3 and 4. The
yoke or back armature of each of these electro-magnets, instead of being made of
soft iron in the usual manner, consists of a permanent steel magnet of horse-shoe

page_text: shape, into the opposite poles n ands of which the respective cores of the electro-
magnets are firmly screwed or otherwise secured. The permanent magnet induces
corresponding polarity in the soft iron cores attached to its poles, and thus they are
rendered in effect permanently magnetic but of opposite polarity.
I prefer to arrange the electro magnets F and F¹ with their similar poles facing
each other, the north pole of F facing the north pole of F¹, and the south poles in
the like manner, in which case the armature E being a neutral piece of soft iron
will be attracted indifferently by either pair of cores when no current is passing.
The helices or coils are so arranged that the direction of the current through them
in reference to the normal magnetism of the cores will produce an opposite effect in
the two electro-magnets. Thus, for example, a positive current will generate an.
electro magnetism which will reinforce and strengthen the normal magnetism of
the electro-magnet F, and partially or wholly neutralize that of the electro-magnet F'.
The armature E will therefore be strongly attracted by F, and slightly, or not at
all, by F¹. A negative current on the contrary will strengthen the normal
magnetism of F¹ and neutralize that of F, causing the armature E to be attracted
in the opposite direction. Thus by transmitting alternate pulsations of positive
and negative electricity through both electro-magnets (these being included in the
same circuit) the armature E may be made to vibrate to and fro with great rapidity.
An important advantage of the arrangement which I have described consists in the
use of a non-polarized armature in lieu of the polarized armature heretofore used,
whereby I am enabled to make this armature exceedingly small and light. This
could not well be done in the case of a polarized armature in consequence of the
danger of de-magnetization when the mass of metal is small, which in practise is
found to be a very serious evil. This objection is entirely overcome by the
arrangement which I have described.
The printing mechanism consists of a lever H fixed upon an arbor or shaft h,
which carries a cylindrical pad or platten I and a paper feeding mechanism J of
the usual construction, by means of which a paper, ribbon, or tape J is drawn
forward to receive the impression of the successive characters as required. K is an
electro magnet which actuates the printing lever by direct action upon its
armature k, which is attached to the axis h of the printing lever H by means of an
adjustable device, which is shown in dotted lines in Figure 1, but will be best
understood by reference to the detail perspective view, Figure 5. The armature k
is mounted upon an arm k'. This arm is loose upon the shaft h, and has a downward
projection or arm k¹¹.
Parallel to this latter is another arm h¹ which is rigidly attached to the axis h.
The arms h¹ and k¹¹ may be adjusted towards or from each other by means of the
screws i and . The screw i passes loosely through the arm ¹¹ and is tapped into
the arm h¹, while the screw is tapped through the arm k" and merely bears
against the arm h¹. By this means the force with which the platen I is pressed
against the type wheel A by the action of the electro-magnet K upon its armature
may be adjusted with great accuracy simply by loosening the screw i and
tightening the screw i', or vice versa, as required.
The printing magnet K is included in the same circuit with the magnets Fand F¹
which control the movement of the type wheel, and is actuated when required
simply by increasing the strength of the current (irrespective of its polarity) by
which the final movement of the type wheel was effected in order to bring the
proper character opposite the platen for printing, the ordinary pulsations which
are of sufficient strength to operate the type wheel armature being altogether
insufficient to actuate the printing devices.
The unison mechanism consists of a detent L affixed to one end of a rock shaft l,
and which, by means of an adjustable spring L2, is normally held in a position
directly in the path of the pin or stop M which is inserted in the type wheel A
and revolves with it. When the pin M in its revolution comes in contact with the
end of the detent L the type wheel is arrested at the zero or starting point and
there held, notwithstanding the action of the escapement and wheel work, until the

page_text: detent is withdrawn. If the type wheel is moving in unison with the transmitting
cylinder a pulsation of considerably more than the normal strength of current
which is sent through the line by the transmitter at the moment of passing the
zero point withdraws the detent or stop L, as hereinafter shown, and allows the
pin M to pass by, consequently the progressive movement of the type wheel is not 5
arrested; but in case the type wheel is thrown out of correspondence with the
transmitter by reason of any disarrangement of the conductors, or the mechanism,
or other cause, so as to fall one or more steps behind the transmitter the pin M
will not reach the stop in time to pass by it at the moment of its withdrawal, and
the type wheel will therefore be arrested and held by the detent L until the latter 1
is withdrawn by the action of the transmitter in the next succeeding revolution,
when the type wheel will necessarily start in unison with the transmitter. Thus
the position of the type wheel is automatically corrected, if found wrong, upon
reaching the zero point in each revolution.
The withdrawal of the detent L from the path of the pin M is effected by a 1
device which will now be described. The motion in each direction of the armature E
which carries with it the escapement is limited by the pendulum arm N (see
Figures 2, 3, and 4) which is fixed upon the same axis d and vibrates between two
adjustable stops O and P. The stop is secured permanently to the frame of the
instrument, but the stop P is mounted upon a short arm p secured to the rock shaft l
which carries the detent L. The tension of the spring L¹ (Figure 1) is sufficient
to hold the stop P in the position shown in the Drawing, except when a pulsation
of increased strength is sent, when the tension of the spring is overcome and the
stop P yields slightly, falling back against the stationary block p¹ and at the same
time withdrawing the detent L from the path of the pin M on the type wheel.
The pendulum arm N although rigidly attached to the axis d is not in itself
entirely rigid, but is preferably constructed of steel and of such a thickness as to
be capable of bending slightly under the force exerted upon it by the armature
after it comes in contact with one or the other of the stops O and P. This
construction gives the arm N a certain degree of resiliency, by virtue of which
when the armature E is released by the electro magnet on either side the recoil of
the arm N aids materially in accelerating the movements of the armature towards
the opposite electro magnet and greatly enhances the rapidity of vibration which it.
is possible to impart to the armature by the alternate action of the electro magnets,
as herein before set forth.
In place of the detent L being moved as above described by the armature E each
time that a pulsation of increased strength is sent, the detent L might, as shewn
by the diagram, Figure 6, be carried by an armature X of an additional electro-
magnet Y, through the coils of which the circuit is also carried. In this case the
armature ✗ may be held away from the magnet by a light spring Z of sufficient
strength to prevent the armature from being drawn to the magnet when a current
of normal strength is passing, but when the current of considerably increased
strength passes the armature is drawn to the magnet and the detent L moved in the
manner previously explained.
When this arrangement is adopted the movement of the armature E may be
limited by stops, both of which are fixed.
As the printing mechanism as well as the mechanism for correcting the type
wheel are both set in action by a pulsation of increased strength it is necessary to
make provision for preventing the impression device from operating whenever a
pulsation is sent forth for the purpose of withdrawing the unison stop; this I effect
by means of a rotating contact point r upon the type wheel which touches an
insulated spring s during each revolution at the instant the pin M is passing the
stop L; this closes a shunt circuit around the printing magnet K, and momentarily
cuts it out of circuit while the unison device is being operated, and thus prevents
the printing mechanism from operating. Another important function of this circuit
closer and shunt is that it reduces the resistance of the main circuit by the amount
of the resistance of the printing magnet K, and to that extent increases the strength

page_text: of the current in the line at the moment the unison mechanism is to be operated;
this in many cases is sufficient to effect the release of the unison stop without the
employment of additional cells of battery at the transmitting station for this
purpose.
The general arrangement of circuits and mechanism which has been herein before
described and explained is clearly shown in Figure 4, in which T and T¹ are the
binding screws for the attachment of the line wires. The normal circuit through
the instrument is from T by wire 1 to electro magnet F, thence by wire 2 to electro
magnet F, thence by wires 3, 4, 5, to printing magnet K, thence by wire 6 to the
other binding screw T. The shunt circuit which cuts out the printing magnet K
starts from the point 4 between the type-wheel magnets F, F, and the printing
magnet K, and goes through the frame of the instrument to the hub of the type
wheel A, and thence through contact-point r, spring 8 (when the latter is in
contact), and wire 8 to the binding post T¹ where it rejoins the main wire.
Thus it will be understood that the three principal working parts of the
apparatus are operated by three different strengths of current. The normal strength
of current, which is also the weakest, is sufficient to actuate the escapement
controlling the type wheel by reversals of polarity, but not sufficient to effect the
printing or to withdraw the unison stop. A certain additional strength is sufficient
to effect the printing also, but not to withdraw the unison stop, which can only be
done by the aid of a still stronger current, and this last is prevented from operating
the printing magnet by the shunting device herein before described. The action of
the printing and unison devices is of course wholly independent of the polarity of
the current.
I claim as regards this part of my Invention,-
First. The combination, substantially as herein before set forth, of a non-polarized
armature common to two electro-magnets, each of which electro-magnets has its
two cores polarized oppositely to each other by a permanent magnet, and which
electro-magnets are arranged with poles respectively facing each other upon
opposite sides of said armature with coils or helices upon the cores of said electro-
magnets connected together in the same circuit in such a manner that a positive
current traversing them tends to neutralize the normal or permanent magnetism of
the electro-magnet on one side of the armature and increase that of the electro-
magnet on the opposite side thereof, while a negative current will tend to produce
the converse of the said action.
Second. The combination, substantially as herein before set forth, of an electro-
magnet or magnets for controlling the movements of a rotating type wheel, an
independent electro-magnet in the same circuit for controlling the printing
mechanism, and a shunt or branch circuit around the printing magnet, which is
momentarily closed at a determinate point once in each revolution of the type-wheel
by a device moving synchronously with the type-wheel.
Third. The combination, substantially as herein before set forth, of a rotating
type wheel, an electro-magnet or magnets for controlling the same, and a unison-
stop which automatically locks the type wheel at the zero point and releases it by
the action of an electro-magnet when the latter is traversed by a current of
increased strength.
Fourth. The combination, substantially as hereinbefore set forth, of an electro-
magnet or magnets for controlling the movements of a rotating type-wheel, a
yielding stop which limits the arc of vibration of the armature of said electro-
magnet while the latter is under the influence of a normal current, and a unison
stop upon the type wheel which is controlled through the yielding stop by
varying the normal strength of current traversing the type wheel magnets.
Fifth. The combination, substantially as herein before set forth, of an electro-
magnet or magnets for controlling the movements of a rotating type wheel, a
yielding stop which limits the are of vibration of the armature of said electro-
magnet or magnets when under the influence of a current of normal strength, a
unison detent or stop normally resting in the path of the type wheel, and adapted

page_text: to arrest the same at the zero point in each revolution, and a connection from the
said yielding stop to the unison detent, which withdraws the same and releases the
type wheel whenever the normal strength of current through the type wheel
magnet is increased.
5
Sixth. The combination, substantially as herein before set forth, of a rotating
type wheel, a unison detent or stop adapted to arrest the rotation of said type
wheel at the zero point in each revolution, an electro magnet which withdraws
said stop and release the type wheel when the normal strength of the current
traversing its coils is increased, and a circuit closer revolving synchronously with
said type wheel, and acting to momentarily increase the strength of current in said 1
electro magnet simultaneously with the arrest of the type wheel by the unison
stop.
Seventh. The combination, substantially as herein before set forth, of a rotating
type wheel, an electro magnet or magnets, an armature, a yielding stop for limiting
the arc of vibration of said armature, and a rock shaft carrying the said yielding
stop, and also a unison detent for locking the type wheel.
Eighth. The combination, substantially as hereinbefore set forth, of a type
wheel, a movable lever constructed in two parts, the platen or impression pad
being mounted upon one part and the armature of the actuating electro-magnet
upon the other, and an adjustable joint or connection between the two parts of the 2
lever.
Ninth. The combination, substantially as herein before set forth, of a vibrating
armature actuated by one or more electro magnets, a resilient arm having one of
its ends rigidly secured to the axis of said armature and stops which limit the
vibration of the free end of said resilient arm in each direction.
I will now proceed to describe the transmitting apparatus.
My improvements in transmitting apparatus consist:-
First. In the combination of a series of pins, mounted upon a revolving shaft, a
series of corresponding keys, each one of which when depressed arrests the motion
of said shaft at a determinate point in its revolution and a commutator actuated
by said shaft, with a second and continuously revolving shaft which is normally
coupled to the commutator shaft, by virtue of the attraction between a charged
• electro magnet and its armature, and a circuit changer which is brought into action
upon the arrest of the commutator shaft by a key, whereby the electro-magnet is
demagnetised and the commutator shaft instantly disconnected from its motor
when so arrested.
Second. In the combination of a series of keys an intermittently revolving shaft
whose movements are controlled by said keys, two wheels provided with wave
shaped projections upon their peripheries, and so mounted that the projections of
one wheel are opposite to the recesses of the other, mechanism for preserving a
constant relation between the revolution of said wheels and that of the shaft and
commutator, and a pin for actuating said commutator, which is caused to oscillate
by the joint action of the said peripheries of said wheels, whereby a positive
oscillatory motion is communicated to the commutator.
Third. In the combination of a series of keys, an intermittently revolving shaft
whose movements are controlled thereby, a rock shaft which performs a determinate
number of oscillations during each revolution of said shaft, and two or more
independent commutators mounted upon said rock shaft, whereby any required
number of separate and independent lines or circuits may be actuated from a single
key board and transmitter.
Fourth. In the combination of a series of pins upon a revolving shaft and a series
of keys, each of which when depressed arrests the motion of said shaft at a
determinate point with a circuit changer, which is actuated by the shaft each time
that its motion is arrested by a key and an auxiliary battery or other means for
increasing the normal strength of current in the main line which is put in action
by said circuit changer, whereby the printing mechanism is actuated at the

page_text: receiving station at the moment the type wheel has been brought into its proper
position.
Fifth. In the combination of a series of keys and an intermittently revolving
shaft under control of said keys, with a circuit changer which is actuated by said
shaft to momentarily augment the normal strength of current in the main line at a
determinate point in each and every revolution of the shaft, whereby, through the
agency of suitable mechanism at the receiving station, the type wheel of the
receiving instrument is automatically brought into unison with the transmitter
once during each revolution.
Sixth. In the combination of a series of pins upon a revolving shaft and a series
of keys, each of which when depressed engages with its corresponding pin, and
thereby arrests the motion of the shaft with a yielding mechanical connection
between said shaft and its driving axis, and a stop for limiting the movement of a
yielding connection, whereby the shock which would otherwise result from the
sudden stoppage of the shaft is diminished, and a means is provided for actuating
a circuit changer for effecting the printing at the receiving station.
Seventh. In the combination of a series of pins upon a revolving shaft, a series of
keys, each one of which when depressed engages with its corresponding pin and
thereby arrests the motion of said shaft; a yielding mechanical connection between
said shaft and its driving axis, and a ratchet wheel and click which acts to prevent
a retrograde motion of the driving axis, whereby the same is held in position
after having been disconnected from the driving pulley and until the key is
released.
Eighth. In the combination of a revolving shaft and a key, which when depressed
arrests said shaft at a determined point in its revolution, with a cam which
maintains said key in a position to arrest the shaft, and a spring which automatically
throws said cam out of position and arrests said key when the latter is depressed
by the operator, whereby the transmitting apparatus is automatically started from
the proper point by the act of depressing the zero key.
Ninth. In the combination of a transmitting cylinder, a series of keys mounted
upon a detached support and a hinged connection between said support and the
base on which it rests, whereby the entire series of keys may be thrown back so as
afford convenient access to the transmitting cylinder and its attachments beneath
the key board.
Tenth. In the combination of an oscillating shaft two pairs of insulated contact
points mounted thereupon and having their faces in the same plane with two
insulated contact springs mounted in the same horizontal plane with each other,
and acting alternately upon said pairs of contact points, whereby all the parts
are rendered more accessable and convenient for the purposes of inspection or
adjustment.
In the accompanying Drawings Figure 7 is a plan view of my transmitting
apparatus, with the upper case and keys partly broken away in order to show the
construction of the transmitting cylinder; Figure 8 is a plan view showing the
transmitting cylinder, the electro magnetic clutch, and the mechanism for actuating
the pole changer, the view being partly in section on the line 2, 2, of Figure 9;
Figure 9 is a side elevation of the same, partly in section, on the line 3, 3, of Figure 8;
Figure 10 is a vertical transverse section on the line 4, 4, of Figure 7; Figure 11 is
a similar section on the line 5, 5, of Figure 7; Figure 12 is an end elevation,
partly in section, showing the mechanism for actuating the pole changers;
Figure 13 is a transverse section on the line 7, 7, of Figures 8 and 9; Figure 14
is a plan view of the pole changers; Figure 15 is a side elevation of the same;
Figure 16 is a view, partly in section and partly in elevation, of one of the binding
screws and its key; Figure 17 is a theoretical diagram illustrating the arrange-
ment of the electric circuits and their connection with the mechanical portions of
the apparatus.
The complete transmitting apparatus may conveniently be regarded as composed
of three divisions, the first of which controls the transmission of the positive and

page_text: negative pulsations by which the intermittent rotation of the type wheel of the
receiving instrument is effected; the second produces the impression of the
required character after the type wheel has been brought into position, and
the third controls the sychronism of the type wheel at the receiving station
and keeps it in correspondence with the transmitting cylinder at the sending
station.
The first part of the apparatus consists of the cylinder A (see Figures 7, 8, and 9),
mounted upon the driving shaft A', which is driven by a pulley A, the connection
between the pulley and the shaft being effected through the agency of a peculiar
clutch, the construction and operation of which will hereinafter be more particularly
described. The cylinder A is placed directly beneath the key board B, B, which
may be constructed of any required number of keys somewhat similar to those of
a piano or other musical instrument. I have illustrated a transmitter having
thirty six keys, corresponding in number to the number of characters and
spaces upon the type wheel of the receiving instrument. Two rows of metallic
pins or stops are inserted in the cylinder A perpendicular to its length; each of
these pins projects vertically from the surface of the cylinder in such a position that
a line drawn through any one of them and the axis of the cylinder will form an
angle equal to one thirty sixth part of the circumference with reference to the line
passing through the next following pin and the axis. It will therefore be under-
stood that the eighteen pins in one row form half of a spiral line around the
cylinder, of which the eighteen pins of the other row constitute the remaining half.
Upon the underside of each key B is a pin or stud 61, best seen in Figure 11, which
when the key is depressed projects into the path of the corresponding pin or stop
upon the cylinder A, and thus arrests its forward motion. It will be understood
therefore that each one of the series of keys B, B, when depressed will arrest the
motion of the cylinder A at a determinate point in its revolution; so long as none
of the keys are depressed, the cylinder A turns with a continuous and uniform
motion in the direction indicated by the arrow, being driven as before explained by
the pulley A", around which passes a belt or band connected with any suitable or
convenient source of power.
In order to disconnect the cylinder A from the pulley A" whenever the former
is arrested by the depression of one of the keys B, B, I make use of an electro
magnetic clutch, the construction and operation of which will now be explained.
Referring to Figures 7, 8, and 9, a is a disc or plate of soft iron, which is rigidly
fixed to the axis A¹ of the cylinder A and revolves with it; a' is an electro magnet,
preferably having four poles arranged with reference to each other, as shown in
Figure 13. This electro magnet, together with the pulley A", is rigidly attached
to the shaft a¹¹, which turns in suitable bearings in line with the shaft A' upon
which the cylinder A is mounted. The electro magnet a' is so adjusted that its
four poles revolve in contact with the plane surface of the soft iron plate or disc a.
The effect of this arrangement is that when the electro magnet a¹ is rendered
powerfully magnetic, the attraction exerted by it upon the soft iron disc a is so
great that the latter, together with the shaft A', is compelled to revolve with it,
and by this means the motion of the revolving electro magnet a' is communicated
to the shaft A¹ and cylinder A. The disconnection takes place instantly upon the
demagnitization of the electro magnet a¹. This demagnitization is effected by
means of suitable mechanism, which will be best understood by reference to
Figure 17. The cylinder A, which is preferably composed of non conducting
material, such as hard rubber, is not attached rigidly to the shaft A' upon which
it is mounted but is loose upon it. The mechanical connection between the
cylinder A and shaft A¹ is a yielding one, and consists of a spiral spring c, one end
of which is attached to a hook inserted in the end of the cylinder, while the other
end is attached to the arm c', the latter being rigidly attached to the shaft A'. At
the opposite end of the shaft A¹ is another similar arm c¹¹, which by virtue of the
tension of the spring c' normally rests against an arm c, projecting from the
cylinder A. The arms c¹¹ and care provided with electrical contact points.

page_text: When these points are pressed together an electric circuit from a local battery D
traverses the coils of the electro magnet a¹. The circuit may be traced as follows:-
From one pole of the battery D by the wire d to the insulated spring d¹, which
bears against the end of an insulated conductor d, passing through the interior of
the shaft all, which is made hollow in order to accomodate it. The conductor d
is connected with one terminal of the four connected coils of the electro magnet a¹,
the other terminal of which is connected directly with the metallic frame upon
which the apparatus is mounted. The arm c¹¹ upon the shaft A¹ is necessarily in
conducting connection with the metallic frame through the bearings in which it is
mounted. The arm c¹¹ is connected with a metallic ring D₁11 surrounding the
cylinder A. Upon this ring as it revolves rests a metallic spring D', which is
preferably provided with a friction roller D". The spring D is connected with
the other pole of the battery D by a wire d¹¹. It will therefore be understood that
when the cylinder A revolves freely the arms c¹¹ and c¹ will be maintained in
contact with each other by the action of the spring c, and that the current of the
local battery D will traverse the coils of the electro magnet a' and keep the same
constantly magnetized, thereby coupling the pulley A" to the cylinder A; but if
one of the keys is depressed by the operator, as shown for example at B in
Figure 17, the pin 6' is thrown into the path of the pin C, and the cylinder A is
arrested while the shaft A' moves forward, and thus breaks the local circuit
between the points c¹¹ and c¹¹¹, which instantly demagnetizes the electro magnet a¹.
The latter however continues to revolve freely with the pulley A", but without
carrying with it the shaft A¹ and its attachments. The ratchet wheel E provided
with a spring click e, as best seen in Figure 13, serves to prevent any retrograde
movement of the shaft A¹ after the cylinder A has been arrested by the depression
of the key and the motor shaft disconnected. When the key B released by the
operator the cylinder A is left free to revolve, the local circuit between c" and c¹11
is again closed, and the apparatus moves forward as before until connected in a
similar manner by the depression of some other key.
In order to actuate the escapement which controls the movements of the type
wheel of the receiving instrument it is necessary that thirty six electrical pulsations
should be transmitted over the line during each complete revolution of the
cylinder A. These pulsations are transmitted alternately from the positive and
negative poles of the battery by means of a commutator of peculiar construction,
which is termed a pole changer, the operation of which will be best understood by
reference to the diagram in Figure 17, in which F represents a shaft, upon which
is fixed a piece of hard rubber or like insulating material F¹. In this are inserted
four metallic pins f, f¹, f", f. Upon these pins rest two metallic springs G₁
and G, which are so arranged in reference to the said pins that when the shaft F
is in one position, which is that shown in the Figure, the spring G¹ rests upon the
pin and spring G₁ upon the pin f¹. If however the shaft F be caused to revolve
a short distance in the direction indicated by the arrow the spring G₁ will be
brought into contact with the pin f", and thereby lifted from pin f, and in like
manner the spring G" will rest upon pin f and be lifted from the pin f'.
The spring G" is electrically connected with the earth through the wire g¹,
while the spring G₁ is connected with the line leading to the receiving station or
stations by the wire g¹. The pins fand fill are connected together and with the
copper pole of the battery H by the wires h' and h. The pins and f" are
connected with each other and with the zinc pole of the battery H by the wire h¹.
Thus it will be understood that if the shaft F be caused to oscillate or rock
backwards and forwards alternate positive and negative pulsations from the
battery H will be transmitted over the line. In practice any required number of
separate and independent lines may be operated from one key board and trans-
mitter by making use of as many separate commutators or pole changers as there
are single lines to be operated, and mounting them all upon a single shaft F. I
have shown in Figures 7 and 9 two pole changers thus operated in connection
with the transmitter, and it is obvious that an indefinite number of them may, in

page_text: like manner be operated by the single shaft F which will hereinafter be termed a
rock shaft.
The two
The description which has been given of the construction and mode of operation
of the pole changer is sufficient to illustrate its general principle. Such a pole
changer in principle is not new and in itself forms no part of my present Invention.
I prefer however to construct my pole changers for actual use in an improved
form which will be best understood by reference to Figure 14 and 15.
contact springs G and G" which are connected respectively with the line and with
the earth instead of being placed one above the other as in the diagram, Figure 17,
are placed side by side in the same horizontal plane as in Figure 14.
arrangement I am enabled to place all the four. contact points f, f¹, f¹¹, f¹¹¹, upon
the upper surface of the insulating block F which supports them. By this mode
of construction a very important advantage is gained, inasmuch as the adjustment
of the contact points with reference to each other and to the contact springs which
work upon them is much more easily performed for the reason that all four of the
contacts are visible to the eye, and are conveniently accessable at the same time.
By this
Screws W, W, are also provided on opposite sides of the rock shaft F, which
screws serve the double purpose of securing the support F¹ of the contact points to
the rock shaft F and of enabling the same to be adjusted upon the shaft with
reference to the arm K¹¹¹.
The oscillation of the rock shaft F is effected by means of the hereinafter
described mechanism.
Upon the end of the shaft A¹ which carries the cylinder A is fixed a wheel I
having its periphery formed into alternate recesses and projections of a wave like
form, as best seen in Figure 12. Directly above and in the same plane with the
wheel I is mounted another precisely similar wheel J. The number of projections
and recesses upon each of these wheels taken together is equal to the number of
pins upon the cylinder A, and also to the number of characters and spaces upon
the type wheel of the receiving instrument. The wheels I and J are connected to
each other by means of toothed wheels i, j, having each a like number of teeth, the
wheel being fixed to the shaft A and communicating its motion to the wheel j.
The wheels I and J are so mounted with reference to each other that the projections
of one wheel are precisely opposite to the recesses of the other as they revolve, as
will be best understood by reference to Figure 12. The space between the wheels I
and J is just sufficient to admit a pin k which is inserted in the arm K of a right
angled or bell crank lever K, K.', the other arm of which is connected by a rod K"
with an arm K which is fixed upon the rock shaft F.
It will be understood therefore that as the wheels I and J revolve in the
direction denoted by the arrows, an oscillatory motion will be communicated
through the pin k to the lever K, K¹, and thence to the rock shaft F upon which
the pole changers are mounted, and that the number of oscillations during each
revolution of the cylinder A, will be determined by the number of projections and
recesses upon the wheels I and J.
The amplitude of the oscillations of the pole changers is capable of being
adjusted within the necessary limits by lengthening and shortening the vertical
arm k¹ of the bell crank lever which is made in two parts clamped together by
screws ¹, in order to facilitate such adjustment.
In order to render the mechanism beneath the keyboard conveniently accessible
for purposes of inspection, repairs, or adjustment, I have mounted the keyboard in
such a manner that it may readily be turned back out of the way when necessary.
Each of the keys B, B, is attached to a flat spring b extending rearward therefrom,
and secured by screws or otherwise to a longitudinal wooden support B¹, see
Figure 10. This support B¹ is secured to the base upon which it rests at its lower
rear corner by hinges b", and is preferably held in position by a moveable catch 6¹¹¹
By this arrangement the operator is enabled to turn the key board and its
support B' backwards into the position indicated by the dotted lines in Figure 10,
and thus to obtain ready and convenient access to the mechanism beneath. The

page_text: cover L which protects the mechanism in front is hinged in a like manner at l, so
as to be capable of being turned forward out of the way, as also indicated by the
dotted lines in Figure 10.
The next part of my Invention has reference to the method of bringing the
printing mechanism of the receiving instrument into action, which is effected by
augmenting the normal strength of the actuating current after the type wheel has
been brought into position without reference to the polarity of the final pulsation,
whether positive or negative. The particular manner in which this increased
strength of current is made available, in order to actuate the printing mechanism
of the receiving instrument has been fully described and explained.
The manner in which the necessary increase in the strength of the current for
this purpose is brought about by the transmitting apparatus will now be explained;
M is an electro magnet of the usual construction provided with an armature and
lever m.
The armature lever m oscillates between contact stops, as shown in
Figure 17, the whole in fact constituting a relay of the ordinary and well known
construction, with the exception that the lever m makes electrical contact with its
rear stop, as well as with its front stop. The coil of this electro magnet M is
included in the circuit of the local battery D which controls the electro magnetic
clutch hereinbefore described. The armature lever m of the relay magnet M when
in contact with its front stop, the circuit of the local battery D being closed forms
a connection between the wires h¹ and h of the main battery circuit. When the
armature lever m rests against its back contact, the route of the circuit is trans-
ferred from the wire h to the wire h111.
Included in the circuit of the latter wire is an auxiliary main battery H¹
containing such a number of cells as may be required to produce an addition to the
normal current of the battery H, which shall be sufficient to actuate the printing
mechanism at the receiving station. It will be readily understood therefore that
when the circuit of the local battery D is broken (and this occurs each time that
the motion of the cylinder A is arrested by the depression of a key), the armature
lever m falls on its back contact, thus momentarily throwing the current of the:
auxiliary battery H₁ upon the main line during the time of the pause in the
movement of the cylinder A, as herein before described.
The next part of the Invention relates to the method of actuating the unison
mechanism. This mechanism in the receiving instrument is controlled by a series
of single pulsations of considerably more than the normal strength of the current
which is required to effect the printing, which pulsations are sent through the line
by the transmitter at the instant of passing the zero point in each revolution of the
cylinder and its corresponding type wheel. This zero point upon the cylinder and
type wheel corresponds with the white key at the extreme left of the key board,
and the apparatus is so arranged that at the instant the corresponding pin upon
the cylinder in its revolution comes opposite the pin upon the underside of the zero
key (whether the latter be depressed or not) the strength of the current is
momentarily increased. I prefer to effect this by short circuiting or shunting an
artificial resistance P, Figure 17, which may be placed at any convenient point in
the circuit of the main line q¹. This shunt circuit is formed by the wire p¹¹ a
contact point P and metallic spring P¹ and wire p'. Whenever P¹ touches the
contact point p, the resistance P is cut out and the strength of the current on the
main line thereby augumented. This is effected momentarily once in each
revolution at the required point by means of the pin R on the cylinder best seen in
Figure 10, which engages with a cam shaped projection P", on the spring P¹, and
thus throws the latter momentarily into contact with the point p. The manner in
which this pulsation acts upon the receiving instrument to maintain the same in
correspondence with the transmitting cylinder has been hereinbefore described.
When the transmitting apparatus is at rest and in readiness to commence the
transmission of a message of communication, it is necessary that the cylinder A
should always stand at the zero point. I therefore provide a small right angled
ever or cam having a suitable handle S, which is pivoted to the frame of the

page_text: instrument just above the zero key at the extreme left of the key board, as seen
in Figures 7 and 11. When the handle S is in a horizontal position as in
Figure 11 the short ends of the lever presses against the cam shaped projection t
on the upper surface of the zero key, and thus depresses it so that the type wheel
is arrested by the action of the zero key in the usual manner. When it is desired
to commence the transmission of a communication a slight touch of the operator's
finger upon the zero key withdraws the projection t from its contact with the short
arms of the cam lever, whereupon the spring 8¹ throws the handle S into an
upright position, in which it remains until the operator again wishes to lock the
transmitting cylinder at zero when he places the handle in a horizontal position as
before.
It is obvious that numerous changes may be made in the arrangement of the
circuits at the transmitting station, by means of which the required results are
produced at the receiving station. For example, the increase of strength which is
required to actuate the printing mechanism might be obtained by shunting a
normal resistance instead of making use of an auxiliary battery. On the other
hand an auxiliary battery might be employed to actuate the unison mechanism
instead of the devices which I have shewn. The manner of arranging these
modifications will be obvious to those skilled in the art, and will therefore
require no detailed explanation in this place. I prefer to construct the binding
posts for the attachment of the line ground and battery wires in the manner
shown in Figure 16, in which U is the base of the posts, from which projects
the screw u, preferably from the same piece of metal. The connecting wire is
bent into a loop and clamped between the base U and a nut u in a manner
well understood. The upper part of the nut u is made rectangular in form so
as to admit of a key V with a rectangular hole in it, being applied in the
manner of a wrench so as to clamp the nut u forcibly against the wire.
An adjustable resistance may be placed in the circuit of the local battery D, see
Figure 17, for the purpose of regulating the strength of the electro magnet M when
necessary or desirable.
I claim as regards this part of my Invention,-
First. The combination substantially as herein before set forth of a series of pins
or stops mounted upon a revolving shaft, a series of keys corresponding with said
pins, each one of which when depressed engages with its corresponding pin and
thereby arrests the motion of said shaft at a determinate point in its revolution,
a commutator or pole changer actuated by said shaft, a continuously revolving
shaft which is normally coupled to the commutator shaft by the attraction between
an electro magnet mounted upon one of said shafts, and its armature mounted upon
the other, and a circuit breaker which is brought into action by the engagement of
any one of the keys with its corresponding pin upon the commutator shaft, to
demagnetize said electro-magnet, and disconnect the commutator shaft from its
motor.
Second. The combination substantially as hereinbefore set forth of a series of
keys, an intermittently revolving shaft, the movements of which are controlled by
said keys, two wheels having an equal number of wave shaped projections and
recesses upon their peripheries, and so mounted that the projections of one wheel
are opposite to the recesses of the other, mechanism for preserving a constant
relation between the revolutions of said wheels and that of the said shaft, a
commutator or pole changer, and a pin for actuating said commutator, which is
caused to oscillate by the joint action of the wave shaped peripheries of said wheels.
Third. The combination substantially as hereinbefore set forth of a series of keys,
an intermittently revolving shaft, the movements of which are controlled by said
keys; a rock shaft which performs a determinate number of oscillations during
each revolution of said shaft, and two or more commutators for actuating separate
circuits mounted upon said rock shaft.
Fourth. The combination substantially as herein before set forth of a series of
pins or stops mounted upon a revolving shaft, a series of keys corresponding with

page_text: said pins, each one of which when depressed engages with its corresponding pin,
and thereby arrests the motion of said shaft at a determinate point in its revolution,
a circuit changer which is actuated by the shaft each time that its motion is
arrested by a key, and an auxiliary battery or other means for increasing the
normal strength of current in the main line, which is put in action by said circuit
obanger.
Fifth. The combination substantially as hereinbefore set forth of a series of keys,
an intermittently revolving shaft, the movements of which are controlled by said
keys, and a circuit changer which is actuated by said shaft to momentarily augment
the normal strength of current in the main line at a determinate point in each and
every revolution of the shaft.
Sixth. The combination substantially as hereinbefore set forth of a series of pins
or stops mounted upon a revolving shaft, a series of keys corresponding with said
pins, each one of which when depressed engages with its corresponding pin and
thereby arrests the motion of said shaft, a yielding mechanical connection between
said shaft and its driving axis, and a stop for limiting the movement of said yielding
connection.
Seventh. The combination substantially as herein before set forth of a series of
pins or stops mounted upon a revolving shaft, a series of keys corresponding with
said pins, each one of which when depressed engages with its corresponding pin
and thereby arrests the motion of said shaft, a yielding mechanical connection
between said shaft and its driving axis, and a ratchet wheel and click for
preventing a retrograde motion of the driving axis.
Eighth. The combination substantially as hereinbefore set forth of an intermittently
revolving shaft, a key which when depressed arrests said shaft at a determinate
point in its revolution, a cam which acts to maintain said key in a position to
arrest the shaft, and a spring which automatically throws said cam out of position
and releases said key when the latter is depressed by the operator.
Ninth. The combination substantially as herein before set forth of transmitting
cylinder, a series of keys mounted upon a detached support, and a hinged
connection between said support and the base on which it rests.
Tenth. The combination substantially as hereinbefore set forth of an oscillating
shaft, two pairs of insulated contact points mounted thereupon with their faces in
the same plane, and two insulated contact springs mounted in the same horizontal
plane with each other, and acting alternately upon the said pairs of contact
points.
In witness whereof, I, the said Henry Van Hoevenbergh, have hereunto set
my hand and seal, this Nineteenth day of March, in the year of our Lord
One thousand eight hundred and eighty one.
HENRY VAN HOEVENBERGH. (LS.)