Year: 1888

page_text: Date of Application, 28th Mar., 1888
Complete Left, 20th June, 1888
Complete Accepted, 27th July, 1888
R
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake and Co., Patent Agents
Southampton Buildings, in the County of Middlesex do hereby declaro 'the nature
of the said Invention to be as follows:-
This Invention is embodied in a transmitter or instrument for governing the-
transmission of electric impulses over a circuit for the purpose of operating individual
signalling instruments or other apparatus of a similar nature.
•
The transmitter is especially intended for operating individual signalling instruments
one at each of the different stations on a single line and each instrument having an
electro magnet and actuating armaturo operated by successive electric impulses of
proper strength and duration to actuate a step by step device and the said magnet also
controlling a unisoning armature held in position to arrest the step by step device
while the actuating currents are being applied and being retained by residual
magnetism between the successive actuating currents which cause the actuating
armature to vibrate.
The said unisoning armature is so adjusted as to be released or retracted upon the
application of rapidly alternating currents such as are produced by a magneto electric
generator, or by a very feeble current of short duration and of opposito polarity to
those employed for actuating the step-by-step devices, and the signalling instrument
which is placed in circuit by the step-by-step controlling device at the desired station
is also actuated by the alternating or magneto electric currents which are however,
not powerful enough to move the step by step actuating armature.
The transmitting instrument forming the subject of this invention is adapted to
automatically transmit a number of actuating currents or impulses by which the step
by step dovices of all the signal controlling instruments on the circuit are moved far
enough to bring them to the unison position at which they are arrested by the

page_text: unisoning armature, immediately after which the transmitting instrument causes an
alternating magneto current or feeble battery current of opposite polarity to the
actuating currents to be sent over the line for a moment and thus effects the release of
all the step by stop devices by the unisoning armatures, after which the transmitting
instrument sends a definite number of actuating impulses by which all the stop by
step devices are advanced a certain number of steps requisite to place the signalling
instruments at the station to be called in operative condition, the said number of steps
placing but one such instrument in circuit at a time, after the manner well known to
those familiar with individual signalling apparatus.
All these currents are caused to be transmitted in the proper number and proper
order by a single movement of the operator who merely turns a crank about once
around a dial and stops it opposite the number on the dial corresponding to the station
to be called the said movement of the crank actuating and controlling the mechanism
of the motor by which the required currents are transmitted, and the whole operation
of sending the call being very quickly performed.
It is desirable for the host operation of signalling instruments that currents of about
the same strength should always be used and as the different lines of a telephone
exchange are likely to vary widely in resistance the currents from the same generators
or batteries would vary widely in strength in accordance with the well known laws
unless means were provided for preventing such variation.
The transmitting instrument forming the subject of this invention contains appliances
for equalizing the resistance of the different lines with which the instrument may be
used as follows;
The signalling instruments and current generators are properly proportioned to
operate with lines of the greatest resistance in the exchange.
The transmitting instrument has several resistance coils which just before the
transmitting part of the instrument is operated are all in the circuit.
The act of turning the crank to set the transmitter in operation first moves a switch
or circuit changer by which portions of said resistance are successively removed from
the circuit thereby increasing the strength of a current which is then put on the
line.
An electro magnet is included in the said circuit and its armature is properly
adjusted to be attracted when the current reaches the proper strength for oporating
the instruments.
The lever of the armature of the said magnet when thus attracted arrests the circuit
changing device by which the resistance coils are being cut out and thus retains the
proper amount of resistance in circuit until after the signalling currents have been
transmitted.
The Invention also consists in many combinations and details of construction which
will be hereinafter described, contributing to the certainty and efficiency of operation
of the instruments.
The various operative parts are supported on frame work consisting of a series of
plates connected by rods or pillars.
The rear plates are smaller than the front plate and may receive a cylindrical casing
to enclose the working parts.
For convenienco in reference it may be stated that the devices that directly control
the circuit are mainly between the first and second plates and the mechanism that
regulates or governs the movement of the said devices is mainly between the second
and third plates and the devices for automatically equalizing the resistance of the
different lines with which the instrument may be used are mainly between the third
and fourth plates it being understood that each operator at the central office of the
telephone exchange is provided with one of these instruments which is switched into
or connected with any subscribers circuit on which a call is to be made in the usual
manner.
The front plate or dial has a portion of its surface graduated and numbered, the
numbers corresponding to the numbers of the stations in any one circuit; and the
whole instrument is controlled and operated by a crank which is turned practically

page_text: once around in the direction of the arrow and brought to the number of the station to
be called where it may be left until another call is to be sent.
The said crank is fixed upon a shaft extending from the front plate to the third
plate and at present the mechanism between the third and fourth plates need not be
referred to.
The said shaft has fixed upon it a disc provided with ratchet teeth located and
spaced with relation to the crank to correspond with the numbers on the dial and being
controlled by a pawl pivoted on the front plate.
Thus when the crank is turned around to any number on the dial, the pawl prevents
the roverse rotation of the said crank and its shaft.
The said shaft has loose upon it a sleeve which extends through the second plate
and at the front of the said plate has attached to it the main circuit controlling disc
or wheel and at the rear of the said plate the sleeve has connected with it a gear
meshing with a train of wheel-work terminating in a regulating device the purpose of
which train is merely to retard and control the speed of movement of the disc when
actuated, as will now be described.
The regulating device consists of an arm on the most rapidly moving arbor of the
retarding train, the said arm having at one or both ends a weight pivoted or hung to
swing outward under centrifugal force which may if desired be resisted by a spring.
The weight turns in a cylinder and as the speed increases the said weight is thrown
outward by centrifugal force and thus has more friction on the cylinder which prevents
further increase in spoed.
The shaft is connected with one end of a spring the other end of which is connected
with the rear disc so that the rotation of the shaft by the crank as before stated strains
the said spring which then tends to rotate the disc in the same direction, the speed
of rotation of the said disc being controlled by the train as before stated, and the
pawl in connection with the disc retains the shaft as before stated with the spring
strained so that the rotation of the shaft may be as rapid as desired while the rear
disc will follow it at a speed controlled by its regulating train.
It will be understood that the tension of the spring tends to rotate the crank and its
shaft in the opposite direction and if the said crank should be released by the operator
before the disc was engaged by the pawl the said crank would fly back rapidly and
might injure the instrument.
To prevent this action the shaft is provided with a gear meshing with a pinion the
arbor of which is provided with a retarding device or governor similar to the one
controlling the train before described.
This governor perunits the shaft and crank to bo turned as rapidly as the operator
readily can by hand but the said governor retards the crank in case it should fly
back in the reverse direction by the action of the spring sufficiently to prevent injury
to the ratchet teeth and pawl or other parts of the instrument.
The rear disc is arrested at,a definite point after it has been turned by the spring
by a locking device consisting of a pawl or hook that engages a pin on the disc
preventing the rotation of the said disc when the said hook is in position to engage
the said pin.
Below the pin ongaging shoulder the hook has a cam face which is engaged by a
projection on the disc when the operator turns the crank once around from any
position in which it may be held by the pawl the said projection striking the cam
face and lifting the book, and thus releasing the disc which immediately begins to
rotate under the stress of the spring in the same direction that the operator is rotating
the crank, but at a slower speed owing to the action of the retarding train.
The disc is thus caused to make one complete rotation after the crank has been
turned once around wholly irrespective of the particular point on the dial at which
the crank is stopped.
The rear stop hook has a second or front stop hook connected with it, that
co-operates with a stop pin on the disc as follows :-
When the rear stop hook is engaged with its pin the front hook is retained high
enough to permit the pin to pass beneath it but after the rear hook has been raised

page_text: and the pin passed it, both hooks fall in nearer to the centre of the disc so that if
the crank were accidentally turned beyond the numbered part of the dial so as to begin
a second revolution the pin on the disc would be arrested by the front hook thus
preventing a second revolution of the crank until after the disc has made one complete
revolution and been arrested in its normal position.
When the disc has nearly finished its revolution from the normal starting point
the pin engages the under part of the rear hook and lifts both hooks before it is
arrested by the shoulder on the rear hook and thus provides for the next operation
of the crank.
In order to further prevent danger of over winding the spring, or of running down
the said spring in case the shaft and parts upon it should be removed from the frame
work and consequently from the control of the pawl and locking devices an arm is
pivoted loosely on the shaft at the side of the rear disc and has its movement with
relation to said disc limited by stops to about a quarter of a turn.
The end of the arm also stands in the path of the projection on the rear disc
in such a manner as to permit about one turn and a quarter of the rear disc with
relation to the other disc but if in any way the shaft should be turned further, the
pin would engage the arm and carry it forward until arrested by the stop when
the shaft would be prevented from turning any further without positively carrying
the rear disc with it.
If on the other hand, the front disc were in any way removed from the control
of the pawl the spring would tend to rotate the shaft backward with relation to the
rear disc but in such backward movement the pin would engage the arm and carry
it along until arrested by the stop when the shaft could not move back any further
with relation to the rear disc and consequently the spring will not be unwound upon
such disengagement of the pawl.
The rear disc is the direct current controlling part of the instrument and is
provided with certain projections which in the rotation of the said disc co-operate with
circuit controlling springs or keys to transmit the requisite currents to line.
The actuating currents or impulses by which the step by step devices of the signal
controlling instruments are moved are governed by a key or circuit controlling
device consisting of a pivoted lever provided with a contact that co-operates with a
stationary contact insulated from the frame work of the machine. The lever is
impelled in the direction to close the contacts by a spring but is moved in the
direction to separate the contacts by the projecting parts of the periphery of the
rear disc.
The said disc is provided with a high projection that stands under the short arm
of the lover when the said disc is arrested in its normal position and which then holds
the lover in its most remote position from the contact and brings another contact
spring connected with the said lever into engagement with a contact insulated from
the frame work of the machine the purpose of which contacts will be hereinafter
explained.
When the rear disc begins to rotate from its normal position the lever drops off
from the high projection and is acted upon by a number of small alternate notches
and projections which vibrate the lover with considerable rapidity and thus by the
contacts transmit a number of actuating impulses that bring all the step by step
devices controlled by the circuit to the unison point. Beyond the notched part is a
plain part which keeps the lover with the contacts separated and while this part of
the disc is in engagement with the lever the projection passes over the spring which
transmits the current by which the unisoning armature is operated to release the step
by step device.
After the projection has passed the spring and the plain part of the disc has passed
the lever a number of large notches and projections arrive in position to actuate the
lever and contacts by which a number of comparatively slow impulses are transmitted,
that actuate the step by step devices in unison with great certainty thus advancing
them to the desired, point to place the instrument at the station to be called in operative
condition,

page_text: A sufficient number of large notches are provided to advance the step by step
device as far as may be required to bring the signalling instrument at any station into
operative condition, but only a certain number of said notches are permitted to operate
on the key at any time, the said number being determined in accordance with the
position to which the lover was turned on the dial as follows:-
A loose cam segment is pivotally connected with the roar disc and has its other
end controlled by a pin on the said disc, which permits the movement of the said
segment between the extreme positions.
In the one position the said segment permits the notches to act on the lever but in
the other position the said segment engages the lever which is wide enough for this
purpose and thus retains the said lever stationary in the same position that it is held
by the unnotched part of the periphery of the rear disc.
This segment is controlled by the pin on the front disc which raises the segment
to one position shortly after its pivoted end has passed the said pin and thus the
position of the pin which depends on the position to which the crank is turned and
held by the pawl determines the time in the rotation of the disc that the segment is
thrown out and the lever removed from control of the teeth.
For example the crank is stoppad opposite the number 6 on the dial and in this
position 6 of the notches will pass by the lever and cause six vibrations thereof
before the segment is thrown out by the pin and the vibration of the lever thus
stopped.
If the crank bad been stopped opposite number 1 the segment would have been
thus thrown out after the first notch had passed and acted on the lever, and so on.
Beyond the large notches the rear disc has a plain portion which retains the key
with the contacts separated and at this time a number of projections at the rear side
of the disc co-operate with a spring which the circuit is closed between the line and a
grounded branch containing the magneto generator, and the magneto electric currents
thus transmitted which ring the bell in that station in which the said bell has been
placed in circuit by the step by step device.
After the plain part has passed the key and the projections have passed the spring
another series of small notches act on the lever producing another series of actuating
impulses by which the step by step devices are again brought to the unison point
thus removing the signalling instruments at all stations from the circuit although
these notches are not depended upon for unisoning the step by step devices the next
time a signal is to bo transmitted.
After the notches have passed the key the projection comes to rest under the said
key leaving the contacts normally separated, and the other contacts connected together
this being the only time that such contacts are connected.
The subscribers line grounded at its outer end passing through the various sub-
scribers stations is connected with the transmitting instrument by the devices
commonly employed at the central office of telephone exchanges, the said connection
being made with any line on which a station is to be called.
The connector by which the instrument is connected with a subscribers line is itself
connected in circuit with the metallic frame work of the instrument including the
shaft, disc, key, and the contacts theroof.
The contact insulated from the frame work as before stated is connected with a
branch wire containing a battery and connected with the ground the said battery
being strong enough to produce the requisite actuating currents in subscribers circuits
of maximum resistance.
The spring is either connected by a branch circuit through resistance with one
terminal of the generator the other terminal of which is grounded, or is connected
by another branch with one pole of a battery the other pole of which is grounded, the
said battery being much smaller than the battery above mentioned and having its
opposite pole connected to the spring from that of the battery connected with the
contact. It is very desirable to provide for connecting either the generator or the
battery with the spring and to change such connection from time to time.

page_text: The spring is connected by another branch with one polo of the generator the other
pole of which is grounded as before stated.
The contact connects with a branch grounded through the telephonic instrument.
The operation is as follows:-
In the normal position the subscribers line is connected by connectors and contacts
and wire through the telephone with the ground.
When the disc is rotated by the devices before described the telephone branch
is first disconnected from the line and the notches of the disc causes a number of
impulses to be transmitted from the battery over circuit rapidly actuating the step
by step devices at the stations.
Then the battery branch is disconnected from the line while the blank part of the
disc passes the key and at this time the projection on the said disc makes contact
with the spring thus sending the current from the generator and resistance or from
the battery as may be most desirable from the said spring to the disc and circuit.
1
The weak current of the battery or the alternating current of the generator 1
weakened by the resistance will act to completely neutralize the magnetism of the
step by step magnets at the stations and will thus release their unisoning stops as
before stated.
Then the large notches will again actuate the key controlling the circuit of the battery
as before stated sending a number of comparatively slow impulses of the said battery 2
which number is determined by the position of the crank and offect of the pin on
the sogmont as before described, and after a sufficient movement to permit the
maximum number of notches that will be required to act, the other projections will
co-operate with the spring while the key is hold open by the blank part of the disc
thus sending the currents from the generator over the circuit to actuate the signalling 2
instrument at that station where such signalling instrument has been put in circuit by
the step by step devices.
It may in many cases be necessary or desirable to render the resistance in circuit
about enough so that the battery and generator currents will act with about the same
strength on the signalling instruments in the different circuits of the exchange.
Such equalizing of the resistance of the circuit is automatically effected by devices
which will now be described being mainly those included between the third and fourth
frame plates together with certain other devices.
These devices comprise a number of different resistance coils which may be wound
on spools and are connected together in series but provided with contact points 3
arranged in an are on an intermediate frame plate.
The rear shaft has its bearings in the fourth and intermediate plates and is in lino
with but disconnected from the unain shaft.
The said shaft carries an arın having a yielding contact which as the said arm
is rotated makes contact with the studs interposed between the different parts of the 4
resistance.
The said arm thus constitutes a switch which when rotated successively cuts out tho
different portions of the resistance included between the studs.
The said arm has a projection engaged by a yielding projection carried by the main
shaft so that when the said shaft is first rotated and before the disc is released as before 4
described the said projection engages with the projection and turns the switch arm in
the direction to cut out the various parts of the resistance.
The spring tube of the contact and the projection pass through a curved opening in
the third plate that permits about a quarter turn of the said parts.
An electro magnet is included in the circuit and its armature is so adjusted as to be 5
attracted when the current, which is gradually being strongthened by removal of the
resistance reaches the normal strength at which the instruments are to be operated.
The armature has an arm which when attracted engages a toothed piece on the
shaft and thus prevents further movement of the said shaft and of the switch arm the
moment the magnet is energized, thus preventing further removal of resistance by 5
the movement of said switch arm.

page_text: When the switch arm is thus positively arrested the projection by which it has
been turned and which is as before stated made yielding, yields and permits the main
shaft to continue its rotary movement.
The switch arin also has a toothed arc which is engaged by a pawl preventing the
said arm from returning to its original position towards which it is impelled by a spring
and at which it is arrested by a stop.
It is necessary that the current of the actuating battery should be on the circuit
during the movement of the switch arm by which the resistance of the line is adjusted
in order that its current may he affected by said resistance and that the magnet may
be operated when the current reaches the proper strongth.
For this purpose the gear or any other part carried by the shaft is provided with a
contact plate that co-operates with a spring to connect the battery to line through the
switch and resistance during that portion of the rotation of the crank in which the
switch arm accompanies it.
As the magnet is in circuit during the subsequent transinission by the disc its
arinature would respond to the impulses transmitted by the said disc.
This would not effect the operation of any part, but in order to prevent the rattling
noise that would ensue, a stopping device is provided that bears against the armature
and prevents it from being retracted as the circuit is broken.
It is necessary however, for the co-operation of said armature with the notched
piece that said armature should be free while the switch arm is making its movement.
For this purpose the said stop is connected, with an arm acted upon by a cam on the
main shaft which turns said stop away from the armature just before the yielding
projection engages the projection of the switch arm and said cam retains tho stop
away from the armature long enough to permit the arm to make its maximum
movement.
It is necessary that the switch arm should start from its original position in which
all the resistance is in circuit each time that these devices are set in operation.
To insure this result the pawl is connected with the rock shaft having an arm
engaged by a pin on the gear connected with the shaft before the yielding projection
reaches the projection of the switch arm. All these operations take place in the
movement of the crank outside of the graduated part of the dial at some point in
which it is held by the pawl after it is turned, and during this part of the movement
of the crank the rear disc remains stationary as it is not released by the pin acting on
the hook until the crank arrives at or nearly at the graduated part of the dial.
The operation of the devices thus far described for automatically adjusting the
resistance of the line in which the subscribers circuit is connected with one terminal
of the magnet, the other terminal of which is connected with the resistance while the
switch arm as well as the contact plate are in electrical connection with the frame
work of the machine.
This spring that co-operates with the contact plate is connected by wire with the
battery which during the entire operation of adjusting the resistance is otherwise
disconnected from the framework of the instrument.
.
When the crank is turned the projection on the gear first engages the arm of the
rock shaft and trips the pawl thereon, permitting the switch arm to be turned back to
its normal position by the spring.
In this position the contact of the said switch arm rests on the stud and the whole
of the resistance is in circuit. Immediately after this the contact reaches the spring
and connects the battery with the frame work of the machine including the switch arm
and thence through the resistance to the subscribers circuit.
At the same time the cam ongages the arm and releases the armature which unless
the circuit is one of maximum resistance will fall back owing to the resistance.
At the same moment the yielding projection will engage the projection and begin
to move the switch arm in the direction to cut out the successive portions of resistance
between the different studs and when by such graded reduction of the resistance the
current arrives at the desired strength, the magnet will attract its armature and will

page_text: arrest the switch arm by engagement of the notched piece and the arm of the armature
and thus prevent the further reduction of resistance.
The yielding projection will spring past its projection and the shaft continue its
further onward movement unaccompanied by the shaft and switch arm.
Shortly after, the cam will disengage the arm and the lock will be brought up by its
spring to engage the armature and prevent it responding to the currents.
After this the crank will be carried on to the number on the dial of the station to be
called having released the disc just before it arrives at the numbered part of the dial
so that the said disc begins its movement before the crank comes to rest at the proper
number on the dial.
If the operator should by accident carry the crank beyond the desired number on
the dial it cannot be turned back and the operator might attempt to carry it wholly
around again.
This would be provented by the stop and the crank when released would fall back
and be hold by the pawl opposite the zero point on the dial.
This would cause the step by step device of the signalling instrument to be turned
wholly around before the generator current was applied by the spring and consequently
no station signal would be in circuit and no false alarm given.
The operator would consequently have to wait until the disc had finished its rotation
and thus raised the stop hook so that the crank could be again operated and this time
stopped at the proper point.
In actual practice it does not require over ton seconds for a complete rotation of the
disc so that but little time is thus lost.
Soveral of the devices herein described are not absolutely essential to the operation
of the transmitter but all contribute to render the instrument convenient and efficient
in operation and it is to be understood that the omission of non-essential devices or
variations in their construction not changing the essential mode of oporation is not a
substantial departure from the invention herein described.
The main shaft is the actuating and controlling shaft for the entire instrument and
the disc is the circuit controlling part, and its various notchos and projections con-
stitute the signalling surface which in conjunction with the contact keys and springs
co-operating with it, determine the character of the current and of the interruptions of
the current by which the required effect is produced on the signal receiving instru-
ments, and it is obvious that the mechanical construction of these parts might be
varied and equivalent devices employed without departing from the invention.
Dated this 28th day of March 1888

page_text: 1 HENRY HARRIS LAKE, of the firm of Haseltino Lake & Co. Patent Agents,
Southampton Buildings in the County of Middlesex do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention is shown embodied in a transmitter or instrument for governing
the transmission of electric impulses over a circuit for the purpose of operating
individual signalling instruments or other apparatus of a similar nature.
"
The transmitter is especially intended for operating individual signalling instruments
one at each of the different stations on a single line and each instrument having an
electro magnet and actuating armature operated by successive electric impulses of
proper strength and duration to actuate a step by step device and said magnet also
controlling a unisoning armature held in position to arrest the step by step device
while the actuating currents are being applied; and being retained by residual
magnetisin between the successive actuating currents which cause the actuating
armature to vibrate.
The said unisoning armature is so adjusted as to be released or retracted upon the
application of rapidly alternating currents such as produced by a magneto electric
generator, or by a very feeble current of short duration and of opposito polarity to
those 'employed for actuating the step by step devices and the signalling instrument
which is placed in circuit by the step by step controlling device at the desired station
is also actuated by the alternating or magneto electric-currents which are however not
powerful enough to move the step by step actuating armaturo.
The transmitting instrument forming the subject of this invention is adapted to
automatically transmit a number of actuating currents or impulses by which the step
by stop devices of all the signal controlling instruments on the circuit are moved far
enough to bring them to the unison position at which they are arrested by the unison-
ing armature immediately after which the transmitting instrument causes an alternating
magneto current or feeble battery current of opposite polaratiy to the actuating
currents to be sent over the line for a moment and thus effects the release of all the
step by step devices by the unisoning armatures after which the transmitting
instrument sends a definite number of actuating impulses by which all the stop by
step devices are advanced a certain number of steps requisite to place the signalling
instruments at the station to be called in operative condition, the said number of
steps placing but one such instrument in circuit at a time, after the manner well
known to those familiar with individual signalling apparatus.
All these currents are caused to be transmitted in the proper number and proper
order by a single movement of the operator who merely turns a crank about once
around a dial and stops it opposite the number on the dial corresponding to the
B

page_text: station to be called, said movement of the crank actuating and controlling the
mechanism of the motor by which the required currents are transmitted, and the whole
operation of sending the call being very quickly performed.
It is desirable for the best operation of signalling instruments that currents of
about the same strength should always be used and as the different lines of a telephone
exchange are likely to vary widely in resistance the curronts from the same generators
or batteries would vary widely in strength in accordance with the well known laws
unless means were provided for preventing such variation.
The transmitting instrument forming tho subject of this invention contains appliances
for evening up the resistance of the different lines with which the instrument may be
used, as follows:-
The signalling instruments and current generators are properly proportioned to.
operate with linos of the greatest resistance in the exchange.
The transmitting instrument has several resistance coils which just before the trans-
mitting part of the instrument is operated are all in the circuit.
The act of turning the crank to set the transmitter in operation first moves a switch
or circuit changer by which portions of said resistance are successively removed
from the circuit thereby increasing the strength of a current which is then put on
the line.
An electro magnet is included in said circuit and its armature is properly adjusted
to be attracted whon tho current reaches the proper strength for operating the
instruments.
The lever of the armature of the said magnet when thus attracted arrests the circuit
changing device by which the resistance coils are being cut out and thus rotains tho
proper amount of resistance in circuit until after the signalling currants have been
transmitted.
The invention also consists in many combinations and details of construction which
will be hereinafter described contributing to the certainty and efficiency of operation
of the instruments.
Figure 1 is a front elevation of a transmitting instrument ombodying this invention,
a portion of the dial or front frame plate being broken away to show the parts
immediately at the rear of it.
Figure 2a sido clevation of the instrument with a portion of the framo work brokon
away to better show the parts of the rear.
Figure 3 a perspective view of the main shaft of the instrument and parts directly
connected therewith.
Figures 4 to 8 various details to be referred to, and
Figuro 9 a diagram showing the circuits, current generators, and various instruments
for controlling the circuit and transmission of currents thereof.
The various operative parts are supported on frame work consisting of
plates a, a¹, a², a³ connected by rods or pillars at a portion of which are broken away
in Figure 2.
The rear plates a³, a², a³ are smaller than the front plate a and may receive a
cylindrical casing indicated in dotted lines at a Figure 2, to enclose the working
parts.
For convenience in reference it may be stated that the devices that directly control
the circuit are mainly between the plates a, a¹ and the mechanism that regulates or
governs the movement of said devices is mainly between the plates a¹, a², and the
devicos for automatically evening up the resistance of the different lines with which
the instrument may be used are mainly between the plates a², a³, it being understood
that each operator at the central office of the telephone exchange is provided with
one of these instruments which is switched into or connected with any subscribers
circuit on which a call is to be-made in the usual manner.
The front plate or dial a see Figure 1 has a portion of its surface graduated and
numbered as shown, the numbers corresponding to the numbers of the stations in any
one circuit; and the whole instrument is controlled and operated by a crank b which
is turned practically once around in the direction of the arrow, and brought to the

page_text: number of the station to be called where it may be left until another call is to be
sent.
The said crank b is fixed upon a shaft 6' best shown in Figure 3 extending from tho
front plate a to the plate a³ and at present the mechanism between the plates a³, a*
need not be referred to.
The said shaft & has fixed upon it a disc c provided with ratchet teeth c' located and
spaced with relation to the crank b to correspond with the numbers on the dial a and
being controlled by a pawl c² pivoted on the front plate a as will be understood from
Figures 1 and 2.
Thus when the crank b is turned around in the direction of the arrow, to any number
on the dial, tho pawl c prevents the reverse rotation of said crank and its shaft.
The said shaft & has loose upon it a sleeve which extends through the plate a¹
and at the front of said plate has attached to it the main circuit controlling disc or
wheel e and at the rear of said plate a¹ the siceve a las connected with it a gear d
meshing with a train of wheel-work d³, №³, dª, d³ terminating in a regulating device (l'
the purpose of which train is merely to retard and control the speed of movement of
the disc e when actuated, as will now be described.
The construction of the regulating device is shown in Figure 4 it consisting of an
arin d on the most rapidly moving arbor d of the retarding train, said arm having
at one or both ends a weight pivoted or hung to swing outward under centrifugal
force which may if desired be resisted by a spring do.
The weight a turns in a cylinder 10 and as the speed increases the said weight is
thrown outward by centrifugal force and thus has more friction on the cylinder 10
which prevents further increase in speed.
The shaft is connected with one end of a spring f see Figure 5, the other end of
which is connected with the disc e as shown so that the rotation of the crank b¹ by the
crank bas before stated strains the said spring which then tonds to rotate the disc e
in the same direction, the speed of rotation of said disc boing controlled by the
train d, etc. as before stated, and the pawl c2 in connection with the disc c retains
the shaft as before stated with the spring f strained so that the rotation of the shaft
may be as rapid as desired while the disc e will follow it at a speed controlled by its
regulating train.
'
It will be understood that the tension of the spring tends to rotate the crank band
its shaft in the direction opposite the arrow, and if the said crank should be released
by the operator before the disc c was engaged by the pawl c³ the said crank would fly
back rapidly and might injure the instrument.
To prevent this action the shaft b₁ is provided with a gear 6 imeshing with a
pinion 63 the arbor of which is provided with a retarding device or governor 6* see
Figure 3 similar to the one controlling the train d', d² etc. before described.
This governor permits the shaft and crank b to be turned as rapidly as the
operator readily can by hand but the said governor retards the crank in case it should
fly back in the reverse direction by the action of the spring f sufficiently to prevent
injury to the ratchet teeth c' and pawl 3 or other parts of the instrument.
The disc e is arrested at a definite point, after it has been turned by the spring f,
by a locking device consisting of a pawl or hook g best shown in dotted lines Figure 1,
that engages a pin g' on the disc e preventing the rotation of said disc when said hook
is in position to engage said pin as shown in Figure 1.
Bolow the pin engaging shoulder the hook has a cam face g² which is engaged by a
projection on the disc c when the operator turns the crank b once around from any
position in which it may be held by the pawl c³ said projection 93 striking the cam
face and lifting the hook g, and thus releasing the disc e which immediately begins
to rotate under the stress of the spring f in the same direction that the operator is
rotating the crank b, but at a slower speed owing to the action of the retarding
train d² d² etc.
The disc e is thus caused to make one complete rotation after the crank 6 has been
turned once around wholly irrespective of the particular point on the dial at which the
crank b is stopped.

page_text: The stop hook g has a second stop hook g connected with it, that cooperatos with
a stop ping on the disc c as follows;-
When the stop hook g is engaged with its pin g¹ the hook is retained high enough
to permit the pin g to pass beneath it as will be understood from Figure 1, but after
the hook g has been raised and the pin g' passed it, both hooks g¹, g³ fall in nearer to
the contro of the disc c so that if the crank b were accidentally turned beyond the
numbered part of the dial a so as to begin a second revolution the pin 9 would be
arrested by the hook thus preventing a second revolution of the crank b until
after the disc e had made one complete revolution and been arrosted in its normal
position.
When the disc e has nearly finished its revolution from the normal starting point
shown in figures 1 and 5, the pin g¹ engages the under part of the hook armig and
lifts both hooks 9 91, before it is arrested by the shoulder on tho said hook g and "thus
provides for the next operation of the crank b.
In order to further prevent danger of over winding the spring f, or of running down
the said spring in case the shaft and parts upon it should be removed from the frame
work and consequently from control of the pawl c² and locking devices g', ', an arm h,
see Figure 5 is pivoted loosely on the shaft at the side of the disc e, and has its
movement with relation to said disc limited by stops h³, ², to about a quarter of a turn.
The end of the arm & also stands in the path of the projection ³ on the disc c as
shown in such manner as to permit about one turn and a quarter of the disc c with
relation to the disc e but if in any way the shaft should be turned further, tho pin g³
would engage the arm h and carry it forward until arrested by the stop ³ when the
shaft b can turn no further without positively carrying the disc e with it.
If on the other hand, the disc c were in any way romoved from control of the
pawl the spring of would tend to rotate the shaft & backward with relation to the
disc e, but in such backward movement the pin g³ would engage the arm and carry
it along until arrested by the stop ¹ when the shaft b¹ could move backward no
further with relation to the disc e and consequently the spring f will not be unwound
upon such disengagement of the pawl c².
The disc e best shown in Figure 5 is the direct current controlling part of the
instrument and is provided with certain projections which in the rotation of the said
disc cooperate with circuit controlling springs or keys to transmit the requisite currents
to line.
The actuating currents or impulses by which the step by step devices of the signal
controlling instruments are movod, are governed by a key or circuit controlling
device k, best shown in Figure 5, consisting of a lever pivoted at k³, and provided
with a contact ², that cooperates with a stationary contact ³ insulated from tho
frame work of the machine. The lever k is impelled in the direction to close the
contacts by a spring k but is moved in the direction to separate the contacts by
the projecting parts of the periphery of the disc e.
The said disce is provided with a high projection e¹ that stands under the short
arm of the lever k when the said disc is arrested in its normal position as shown in
figuros 1 and 5 and which then holds the lever k in its most remote position from the
contact and brings another contact spring & connected with said fever into engage-
inent with a contact kº see Figure 1, insulated from the frame work of the machine
the purpose of which contacts ko, k, will bo horeinafter explained.
When the disc e begins to rotate in the direction of the arrow Figure 5, from its
normal position the lever k drops off from the high projection c¹ and is acted upon
by a number of small alternate notches and projections e which vibrate the lever
with considerable rapidity and thus by the contacts k³, k³, transmit a number of
actuating impulses that bring all the step by step dovices controlled by the circuit to
the unison point. Beyond the notched parte is a plain part e³ which keeps the
lever with the contacts k³, k³ separated and while this part of the disc is in engage-
ment with the lever k the projection el passes over the spring m which transmits tho
current by which the unisoning armature is operated to release the step by stop
device.

page_text: After the projection e¹ has passed the spring m and the plain part e³ of the disc has
passed the lever a number of large notches and projections et see Figure 1, arrive
in position to actuate the lever and contacts 2, 3, by which a number of com-
paratively slow impulses are transmitted, that actuate the step by step devices in
unison with great certainty, thus advancing them to the desired point to place the
instrument at the station to be called in operative condition.
A sufficient number of large notches e* are provided to advance the step by step
device as far as may be required to bring the signalling instrument at any station
into operative condition, but only a certain number of said notches et are permitted to
operate on the key k at any time, the said number being determined in accordance
with the position to which the lever was turned on the dial a as follows;---
A loose cam segment n is pivotally connected at n¹ with the disc e and has its other
end controlled by a pin n² on said disc, which permits the movement of said segment n
between the position shown in full and dotted lines Figure 5.
In the dotted line position the said segment n permits the notches e to act on the
lever but in the full line position the said segment n engages the lover k which is
wide enough for this purpose and thus retains the said levor stationary in the same
position that it is held by the unnotched part e³ of the periphery of the disc e.
This segment is controlled by the pin g³ on the disc c which raises the segment to
the full line position shortly after its pivoted end n' has passed the said pin g³ and
thus the position of the pin g³, which depends on the position to which the crank bis
turned and held by the pawl c², determines the time in the rotation of the disc e
that the segment is thrown out and the lever k removed from control of the
teeth ef.
For example as shown in the drawings the crank b is stopped opposite the number 6
on the dial and in this position 6 of the notches et will pass by the levor and cause
six vibrations thereof before the segment n is thrown out by the pin g³ and the
vibration of the lever & thus stopped.
If the crank bhad been stopped opposite number 1 the segment would have been
thus thrown out after the first notch had passed and acted on the lever k, and
so on.
Beyond the large notches et the disce has a plain portion e, which retains the
key with the contacts ³, separated and at this time a number of projections eo,
seo figuro 2, at the roar side of the disc e cooperate with a spring m¹ by which the
circuit is closed between the line and a grounded branch containing the magneto
generator, and the magneto electric currents thus transmitted which ring the bell in
that station in which the said bell has been placed in circuit by the step by step
device.
After the plain parte has passed the key and tho projections have passed the
spring m another series e' of small notches act on the lever & producing another
series of actuating impulses by which the step by step devices are again brought to
the unison point thus removing the signalling instruments at all stations from the
circuit although these notches are not depended upon for unisoning the step by step
devices the next time a signal is to be transmitted.
After the notches e' lavo passed the key & the projection e' come to rest under the
said key, leaving the contacts k², k³, normally separated, and the other contacts k³, kº,
connected together this being the only time that such contacts k³, k, are connected.
The circuit connections, and mode of operation of the devices thus far doscribod,
will be best understood from the diagram Figure 9.
The subscribers line grounded at its outer end as shown at 2 and passing through
the various subscribers stations S², S' is connected with the transmitting instrument
at 3 by the devices commonly employed at the central office of telephone exchanges,
the said connection being made with any line on which a station is to be called.
The connector by which the instrument is connected with a subscriber's line is
itself connected in circuit as shown at 5 with the metallic frame work of the
instrument including the shaft b' disc e key and contacts ², 4 thereof.
The contact insulated from the framo work as before stated is connected with a

page_text: branch wire 6 containing a battery B and connected with the ground at 7, said battery
being strong enough to produce the requisite actuating currents in subscribers circuits
of maximum resistance.
The spring m is either connected by a branch circuit 8 through resistance R with
one terminal of the generator G, the other terminal of which is grounded at 7 or is
connected by another branch 9 with one pole of a battery B¹ the other pole of which
is grounded, the said battery B' heing much smaller than the battery B and having
its opposite pole connected to the spring m from that of the battery B connected with
the contact ³. It is very desirable to provide for connecting either the generator or
the battery B' with the spring m as shown in Figure 9 and to change such connection
from time to time.
The spring m is connected by another branch 10 with one pole of the generator G
the other pole of which is grounded as before stated.
The contact
instrument T.
connects with a branch 100, grounded through the telephonic
The operation is as follows
In the normal position the subscribers line 2, 3, is connected by 4, 5 and
contacts, o, and wire 100 through the telephone T with the ground.
Whon the disc e is rotated by the devices before described the telephone branch 100
is first disconnected from the line at k³, k, and the notches e² of the disc e causes a
number of impulses to be transmitted from the battery B over circuit 7, 6, k³, k³,
5, 4, 3, 2, rapidly actuating the step by stop devices at the stations S, S³.
Then the battery branch 6, 7, is disconnected from the line ³, k³, while the blank
part of the disc passes the key k; and at this time the projection e¹ makes contact
with the spring m thus sending the current from the generator G and resistance Rt or
from the battery B¹, us may be most desirable from the said spring m to the disc e and
circuit 5, 4, 3, 2.
The weak current of the battery B¹ or the alternating current of the generator G
weakoned by the resistance R will act to completely neutralize the magnetism of the
step by step magnets at the stations and will thus release their unisoning stops as
before stated.
k
Then the largo notches e will again actuate the key controlling the circuit of the
hattory B at k², k³, as before stated sending a number of comparatively slow impulses
of said battery which number is determined by the position of the crank band effect
of the pin ga on the segment n as before described, and after a sufficient movement to
permit the maximum number of notches that will ever be required to act, the
projections will cooperate with the sping m¹ while the key is held open by
the blank parte of the disc thus sending the currents from the generator Gover the
circuit to actuate the signalling instrument at that station-whore such signalling
instrument has been put in circuit by the step by step devices.
It may in many cases be necessary or desirable to render the resistance in circuit
about enough so that the battery and generator currents will act with about the same
strength on the signalling instruments in the different circuits of tho exchange.
Such evening up of the resistance of the circuit is automatically effected by devices
which will now be described being mainly those included between the frame
plates a, a, in Figure 2 together with certain other devices best shown in
figure 3.
These devices comprise a number of different resistance coils which may be wound
on spools indicated at Figure 2, and are connected together in series but provided
with contact points 71, 72, etc. see Figures 6 and 7 arranged in an arc on a frame
plate a see Figure 2.
The shaft t has its bearings in the plates a³, a, Figure 2 and is in line with but
disconnected from the shaft b' as shown in Figure 3.
The said shaft t carries an arm t¹ having a yielding contact t² see Figure 7, which
as the said arm t¹ is rotated makes contact with the studs r1, 72, interposed between
the different parts of the resistance r.
The said arm & thus constitutes a switch as will be readily understood from

page_text: Figure 9, which when rotated in the direction of the arrow in said figure suc-
cessively cuts out the different portions of the resistance included between the
studs, etc.
The said arm t' has a projection t³ engaged by a yielding projection see Figures 3
and 8 carried by the shaft & so that when the said shaft is first rotated and before the
disc e is released as before described the said projection t engages the projection ³
and turns the switch arm t¹ in the direction to cut out the various parts of tho
resistanco r.
pass
The spring tube of the contact (see Figure 7,) and the projection
through a curved opening in the plato a that permits about a quarter turn of
said parts.
An electro magnet to one coil only of which is shown in Figure 2 is included in
the circuit and its armature is so adjusted as to be attracted when the current which
is gradually being strengthened by removal of the resistanco, reaches the normal
strength at which the instruments aro to ho oporated.
The armature t has an arm t' which when attracted engages a toothed piece ta on
the shaft and thus provonts further movement of said shaft and of the switch arm ti
the moment the magnet is energized, thus preventing further removal of resistance
by the movement of said switch arm.
When the switch arm is thus positively arrested the projection by which it has
been turned and which is as beforo stated made yiolding, yields and, permits the shaft 6¹
to continue its rotary movement.
The switch arm also has a toothed arc to which is engaged by a pawl 110 as best
shown in figure 3 preventing the said arm from returning to its original position
towards which it is impelled by a spring " and at which it is arrested by a stop (18,
sen Figure 2.
It is necessary that the current of the actuating battery B should be on the circuit
during the movement of the switch arm by which the resistance of the line is adjusted
in order that its current may be affected by said resistanco and that the magnet to may
be operated when the current reaches the proper strength.
For this purpose the gear b² or any other part carried by the shaft is provided
with a contact plate u that cooperates with a spring u' to connect the battery B to lino
through the switch t' and resistance ? during that portion of the rotation of the crank b
in which the switch arm t¹ accompanies it.
As the magnet t is in circuit during the subsequent transmission by the disc e its
armature would respond to the impulsos transmitted by said disc.
This would not effect the operation of any part, but in order to provent the rattling
noise that would ensue a stopping device w is provided that bears against the
armature to as shown in Figure 2, and prevents it from being retracted as the circuit
is broken.
It is necessary, however, for the cooperation of said armature with the notched
piece that said armature should be free while the switch arm t¹ is making its movement.
For this purpose said stop w is connected, as shown in Figure 3, with an arm w¹ acted
upon by a cam w³ on the shaft b¹ which turns said stop w away from the armature to
just before the projection t engages the projection of the switch arm and said cam wo
retains the stop w away from the armature long enough to permit the arm t¹ to make
its maximum movement.
It is necessary that the switch arm should start from its original position in
which all the resistance is in circuit each time that these devices are set in
operation.
To ensure this result the pawl to is connected as best shown in figure 3, with the
rock shaft having an arm ( engaged by a pint on the gear 6 connected with
the shaft b before the projection trenches the projection t. All those operations
take place in the movement of the crank boutside of the graduated part of the dial a,
at some point in which it is held by the pawl c after it is turned, and during this
part of the movement of the armb the disc e remains stationary as it is not released

page_text: by the pin g³ acting on the hook g until the crank arrives at or nearly at the graduated
part of the dial.
The operation of the devices thus far described for automatically adjusting the
resistance of the line will be readily understood from Figures 3 and 9 in which latter
it is shown that the subscribers circuit 2, 3, is connected with one terminal of the
magnet to the other terminal of which is connected with the resistance while the
switch arm t' as well as the contact plate u are in electrical connection with the frame
work of the machine represented at 5 in the diagram.
This spring u that cooperates with the contact plate u is connected by wire 12 with
the battery B which during the entire operation of adjusting the resistance is otherwise
disconnected from the framo work of the instrument at ², ³.
When the crank b is turned in the direction of the arrow, the projection t¹ first
engages the arm and trips the pawl 10 permitting the switch arm t¹ to bo turned
back to its normal position shown in Figure 3 by the spring ".
In this position the contact t² of said switch arm rests on the stud 1 and the whole
of the resistancer is in circuit.
Immediately after this the contact u reaches the spring u¹ and connects the battery B
by wires 6, 12 with the frame work of the machino including the switch arm t¹ and
thence through the resistaucer to the subscribers circuit.
At the same time the cam w engages the arm w¹ and releases the armature t
which unless the circuit is one of maximum resistance will fall back owing to the
resistance.
At the same moment the projection t will engage the projection to and begin to
move the switch arm t' in the direction to cut out the successive portions of resistance
between the different studs 1, 3, etc. and when by such graded reduction of the
resistance the current arrives at the desired strength, the magnet will attract its
armature and will arrest the switch arm by engagement of 7, 8 and thus prevent tho
further reduction of resistance.
The projection will spring past the projection t and the shaft b¹ continue its
further onward movement unaccompanied by the shaft t and switch arm t.
Shortly after, the cam w³ will disengage the arm w' and the lock w will be brought
up by its spring w³ to engage the armature to and prevent it responding to the
currents.
"
After this the crank 6 will be carried on to the number on the dial a of the station
to be called having released the disce just before it arrives at the numbered part of
the dial so that the said disc begins its movement before the arm & comes to rest at
the proper number on the dial.
If the operator should by accident carry the arm & beyond the desired number on
the dial a it cannot be turned back and the operator might attempt to carry it wholly
around again.
This would be prevented by the stop g', 9, and the crank & when released would
fall back and be held by the pawl e opposite the zero point on the dial.
This would cause the step by step device of the signalling instrument to be turned
wholly around before the generator current was applied by the spring m³ and conse-
quently no station signal would be in circuit and no false alarm given.
The operator would consequently have to wait until the disc e had finished its rota-
tion and thus raised the stop hook g so that the crank b could be again operatod and
this time stopped at the proper point.
In actual practice it does not require over ten seconds for a complete rotation of
the disc e so that but little time is thus lost.
Several of the devices herein described are not absolutely essential to the operation
of the transmitter but all contribute to render the instrument convenient and efficient
in operation, and it is to be understood that the omission of non-essential devices or
variations in their construction not changing the essential mode of operation is not a
substantial departure from the invention herein shown and described.
The shaft 6 is the actuating and controlling shaft for the entire instrument and the

page_text: disc e is the circuit controlling part, and its various notches and projections constitute
the signalling surface which in conjunction with the contact keys and springs
cooperating with it determine the character of the current and of the interruptions of
the current by which the required effect is produced on the signal receiving instru-
ments, and it is obvious that the mechanical construction of these parts might be
varied and equivalent devices employed without departing from the invention.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed as communicated to
me by my foreign correspondents I declare that what I claim is.
First. The controlling shaft movable to and held in different position combined with
a current interruptor controlled by the said shaft and producing a number of electric
impulses dependent on the point at which the said shaft has been stopped, substantially
as described.
Second. The main line and two branch circuits containing sources of different kinds
of electric currents, as for instance, a battery and magneto generator, combined with
a transınitting instrument comprising a movable signalling surface and actuator
therefor, and circuit controlling contacts operated thereby, controlling the connection
of said branches with the main line, substantially as and for the purpose described.
Third. The inain line and three branch circuits, one containing a battery, one a
magneto generator and the third containing a source of currents of opposite polarity
to that of the said battery, combined with a transmitting instrument comprising a
movable signalling surface and actuator therefor, and circuit controlling contacts
operated thereby, by which tho said branches are connected to line. at different times
during a single operation of said signalling surface, substantially as and for the
purpose described.
Fourth. The actuating shaft and wheel having a signalling surface loose thereon,
and actuating spring connecting said shaft and wheel combined with a stop for said
wheel released by said actuating shaft and a second stop connected with said wheel
stop and operated thereby, the second stop being arranged to arrest the actuating shaft
except when the first is engaged with the said wheel, substantially as described.
Fifth. The actuating shaft and transmitting wheel loose thereon, combined with an
actuating spring connecting the said shaft and wheel, an arm loose on said shaft and
stops cooperating with said arm on said wheel and a projection cooperating with
said arm connected with said actuating shaft substantially as and for the purpose
described.
-
Sixth. The actuating shaft and disc fixed thereon having a portion of its periphery
provided with ratchet teeth combined with a pawl to engage said teeth; a circuit
controlling wheel loose on said shaft and an actuating spring connecting said shaft
and wheel, and a stop for said wheel operated to release the wheel by the movement
of the shaft, substantially as described.
Seventh. The actuating shaft movable to and held in different positions combined
with a circuit controlling wheel having a signalling surface and electric contacts
controlled thereby ; a segment connected with said wheel and a projection cooperating
with the said segment connected with the actuating shaft; whereby the said segment
is moved to prevent a portion of the signalling surface from operating the contacts,
substantially as described.
Eighth. The combination of the main circuit and generator of electricity therein
with resistance in said circuit and contact points between different portions of said
resistance, a switch movable, over the said contact points and an electro magnet
included in said circuit and an armature therefor which engages and arrests the said
swtich when the attraction of the magnet overcomes the retractor of the armature,
substantially as described.
Ninth. The combination of the actuating shaft with a movable switch engaged by
said shaft and an electro magnet and its armature that arrests the said switch; a lock
that retains the said switch in the position to which it has been moved, and a releasing

page_text: dovice for said lock operated by said shaft before the latter engages the said switch,
substantially as and for the purpose described.
Tenth. The combination of the actuating shaft with a movable switch engaged by
said shaft and an electro magnet and its armature that arrests the said switch; a
lock that holds the said armature up to its magnet and an actuator for said lock on
said shaft by which the armature is released while the switch is engaged by the shaft,
substantially as and for the purpose described.
Eleventh. The main circuit and branch therefrom containing a telephone instrument
combined with the circuit controlling wheel having a signalling surface one portion
of which cooperates with electric contacts to connect the said telephone branch to
line when the said wheel is arrested in its normal position, substantially as
described.