IMPROVEMENTS IN AUTOMATIC ELECTRIC RAILWAY-SIGNALLING APPARATUS
Year: 1881

page_text: LETTERS PATENT to William Morgan-Brown, of 38, Southampton Buildings,
Chancery Lane, London, Patent Agent, for an Invention of "IMPROVEMENTS
IN AUTOMATIC ELECTRIC RAILWAY-SIGNALLING APPARATUS." A communi-
cation from abroad by Oscar Gassett and Israel Fisher, both of Pittsburgh,
Pennsylvania United States of Ainerica.
COMPLETE SPECIFICATION filed by the said William Morgan-Brown at the
Office of the Commissioners of Patents on the 30th August 1881...
WILLIAM MORGAN-BROWN, of 38, Southampton Buildings, Chancery Lane,
London, Patent Agent. IMPROVEMENTS IN AUTOMATIC ELECTRIC RAILWAY-
SIGNALLING APPARATUS." A communication from abroad by Oscar Gassett and
Israel Fisher, both of Pittsburgh, Pennyslyvania, United States of America.
This Invention relates to that system of automatic electric railway signalling
apparatus which consists in dividing the whole or the portion of the length of a
line of railway in signal sections of any required or convenient length (which length
corresponds to the minimum interval of space which it is desired to preserve
between trains moving upon the same track), and in guarding each of said sections
by a signal placed at or near the entrance of such section, which signal is actuated
or controlled by electro-magnets included in electric circuits extending the entire
length of the signal section to which it appertains, said electro magnets being in
turn controlled through the electric circuit by a moveable circuit closer attached to
the train.
By this means the passage of a train over each successive signal section causes a
danger signal to be exhibited at the entrance of such section from the time that
the train enters it at one end until it leaves it at the opposite end, when the danger
signal is withdrawn or discontinued, leaving the way clear for the next succeeding
train.
It has been found in practice that it is frequently desirable and necessary to
continue a given dauger signal in action after the train which sets it in action has

page_text: passed off from the section which the signal is designed to guard, and until such
train has passed over the next section in advance or a certain portion thereof, by
which an additional security is provided, especially upon dangerous portions of the
road, such as sharp curves or descending grades.
This Invention consists partly in a combination of electric circuits and apparatus
in which the several circuits appertaining to the different signal sections, instead of
being entirely independent of each other, as in the ordinary arrangement, are made
to act to a certain extent dependently, so that while each signal is, as heretofore,
under the direct control of a train which is traversing the section appertaining
thereto, it is also under the indirect control of the same train through the agency
of the next signal circuit in the series during the time in which the said train is
traversing a certain portion of the next signal section.
It also consists in combination of a series of normally closed railway signalling
circuits, each of said circuits including a battery, an electro magnet, and a section
of insulated railway track forming part of said circuit between the battery and the
electro magnet, with circuit breakers placed in each alternate circuit of the series
and not in the intermediate circuits, oach of which circuit breakers is controlled by
an electro magnet included in the adjacent intermediate circuit.
Also in the combination of a series of normally closed railway signalling circuits
a circuit breaker placed in each alternate circuit of the series, which is controlled
by an electro magnet included in the adjacent intermediate circuit and a series of
electro magnets for actuating signals, each of which is under the control of three
successive signalling circuits.
Also in the combination of a secondary circuit for actuating an electro magnet
controlling the movements of a signal, two independent circuit breakers placed in
said secondary circuit, and two independent primary signaling circuits respectively
controlling the action of the said circuit breakers, which primary circuits are
themselves actuated successively by a train which traversing the signal section
protected by said signals.
Also in the combination of two independent primary signaling circuits which are
acted upon successively by a train while traversing a signal section, two inde-
pendent circuit breakers controlled respectively by the said primary circuits when
so acted upon by the train, an electro magnet for actuating a signal which is
included in a secondary circuit under the control of both of said circuit breakers,
and an electro magnet for actuating the signal of an adjoining signal section which
is included in a secondary circuit under the control of one of said circuit breakers,
but not under the control of the other.
This Invention also consists in a novel form of signal controlled-by-the-electric-
currents in the signalling circuits controlled by the trains or by the movement of
switches, draw bridge bolts, and so forth, the said signal consisting in a motor to
set the signal in different positions, and the detent mechanism therefore consisting
of the following elements, viz., the detent arms and stops therefor combined with
detaching arms, one to disengage each of the said stops, and the electro magnet
and its armature adapted to engage and arrest the movement of one only of the
said detaching arms when attracted, and the other of the said arms only when
unattracted.
Also in a motor and its safety and danger detent arms and two stops, one to
engage the said safety and the other to engage the said danger detent arms,
combined with two detaching arms and an electro magnet and its armature to
control them, it being adapted to hold only one of the said arms at one time,
the said devices being arranged to operate as described, whereby when the
condition of the magnet is changed one of the said detaching arms is released to
detach one of the stops and allow the motor to move and change the position of
the signal.
Also in a motor and detent shaft and detent arms thereon and two stops, each to
engage an alternate pair of the said arms, combined with two detaching arins, one
to disengage one and the other to disengage the other of the said stops from its

page_text: corresponding detent arm and restoring devices operated by the motor in its
movements, whereby when one of the said detaching arms is restored to the
position from which it can operate to again release the motor and permit it to move.
Also in a railway signal apparatus the signal hammer or disc and motor to set
it in different positions, and electro magnet to control the said motor, combined
with a circuit controller in circuit with the said magnet operated by the said
motor when nearly run down, whereby the magnet is retained in one condition
and the danger signal remains permanently displayed until the motor is wound up.
Also in a detent shaft turning uniformly with the signal shaft and having detent
arms corresponding to the safety and danger position of the signal, the said arms
being provided with stop pins, those of the safety arms being on the side thereof
opposite to those of the danger arms, combined with safety and danger stops to engage
the said safety and danger pins respectively, and detaching arms to disengage them
therefrom, each of the said detaching arins being held by the armature of the
electro magnet, while the corresponding stop is engaging its pin in position to operate
upon and disengage the said stop as soon as the condition of the magnet is changed.
Also in the main winding shaft of the motor screw threaded and provided with
a nut and a device to prevent the said nut from rotating with the said shaft,
combined with an electro magnet to control the operation of the said motor and
circuit closing springs in circuit therewith, and adapted to be separated by the.
said nut to break the circuit when the nut is near the end of its movement along
the mainshaft caused by the rotation of the said shaft in actuating the machine.
Also in the combination and a mechanically moved signal of a detent or stop
therefore, and a cushioning device interposed between it and the framework,
whereby the signal is gradually stopped without shock to the parts.
The Invention also embodies interlocking apparatus for the signal and a switch,
whereby the switch rails cannot be moved until the signal is properly set, and
consists in the combination of the movable rails of a switch, a rigid bar or rod
connecting the same with each other, a lever for moving said rails, movable toes
situated between the. movable rails for locking said connecting bar and rails in
their normal position, and independent mechanism for moving said toes for the
purpose of locking and unlocking the switch rails.
Also in the combination of the moveable rails of a switch, a rigid bar or rod
connecting the same with each other, a lever for moving said rails, moveable toes
situated between the moveable rails for locking said connecting bar and rails in
their normal position, an independent lever for moving said toes, and a connection
from said independent lever to the distant signal, whereby the latter is operated.
Also in the combination of the moveable rails of a switch, a rigid bar or rod con-
necting the same, a lever for moving said rails, moveable toes for locking said con-
necting bar and rails in their normal position, an independent lever for moving said
toes, a connection for operating a distant signal, and a bolt for securing said indepen-
dent lever, which is actuated by the switch lever when fastened in its normal position.
This Invention also embodies a form of signal to be actuated by the magnetic
force produced by the electric current instead of mechanically actuated and merely
controlled by electricity, and consists in the combination of an electro magnet and
an armature which moves towards and from its poles in a plane perpendicular to
the axis of the cores, and parallel to the face of the poles of said electro magnet,
and which presents an inclined or helical surface to the said poles.
Also in the combination of an electro magnet an armature which moves towards
and from its poles in a plane perpendicular to the axis of the cores and parallel to
the face of the poles of said electro magnet, and which is horizontally tapered so as
present a surface of constantly increasing breadth to the pole as it moves towards
it and across the magnetic field.
Also in the armature of an electro magnet constructed substantially as herein after
set forth, consisting of two wings or blades rotating upon an axis parallel to the cores
of the electro magnet, which present an inclined or helical surface to the respective
poles of said electro magnet.

page_text: Also in the armature of an electro magnet constructed substantially as herein
after set forth, consisting of two wings or blades rotating upon an axis parallel to
the cores of the electro magnet, each of said wings forming a section of a disc of
which said axis is the centre.
Also in the combination of an electro magnet an armature which moves toward
and from its poles in a plane perpendicular to the axis of the cores and parallel to
the face of the poles of said electro magnet, a detent controlled by an independent
armature which normally locks the first mentioned armature in its position of rest,
but is withdrawn by the action of the same electric current which is employed to
effect the movement of the first mentioned armature.
Also in the combination of an electro-magnet an armature which moves towards
and from its poles in a plane perpendicular to the axis of the cores parallel to the
face of the poles of said electro magnet, a detent controlled by an independent
armature, which is held in position to lock the first mentioned armature by the
action of the same electric current which effects the movement of the said armature,
and a spring which withdraws the locking detent from the first armature when the
second armature is released.
Also in the combination of an electro magnet, an armature, a signal disc
mechanically connected to and moved by said armature, a battery for actuating
said electro magnet, which battery is composed of two sections, and a circuit
changer actuated by the movement of said armature, which disconnects one section
of said battery from the electro magnet just before the signal disc has been brought
to its displayed position.
Figure 1 is a diagram illustrating the application of my Invention to a railway
track, showing one complete signal section with its accompanying electric circuits
and apparatus in a normal position of rest; Figure 2 shews the same in the act of
being operated by the passage of a locomotive or train; Figure 3 is a front eleva-
tion of one of the signal machines, the parts being shown in the position assumed
when the controlling electro magnet is vitalized, the signal then indicating safety;
Figure 4, a similar view of a portion of the devices shewn in Figure 1, but with
the magnet demagnetized and the parts in position to give the danger signal;
Figure 5 is a top view, and Figure 6 an end elevation of the apparatus in the
position shewn in Figure 1.; Figure 7, a rear view of one of the detaching arms,
illustrating its operation when brought into engagement with the armature lever;
Figures 8 and 9, a side elevation and top view of the automatic circuit breaking
mechanism for breaking the main circuit, and thereby giving a danger signal and
-preventing-further-movement-of_the_parts_when_the_weight needs to be removed;
Figures 10 and 11, elevations of the signal proper in its two different positions on
a reduced scale; Figure 12, a top view thereof; Figure 13, a detail of the
cushioning device; Figure 14, a modification thereof; Figure 15 is a vertical
elevation of a switch operating mechanism provided with interlocking mechanism
for its corresponding signal; Figure 16 is a plan view of the same; Figures 17, 18,
and 19 are detached and enlarged views, partly in section, of certain portions of
the mechanism; Figure 20 is a front elevation of the signal operating mechanism
and visual signal actuated by the electric currents; and Figures 21 and 22 are plan
views of the same showing the mechanism in two different positions, respectively
adapted to display or conceal the signal disc.
In Figure 1, A2, A3, represents one of the series of signal sections in which the
railway is divided.
These sections are usually in practice from one to two miles in length.
A portion of one of adjacent signal sections in each direction is shown at A', A³.
At the entrance of each signal section with reference to the direction in which
the trains move, as indicated by the arrow, is placed a signal as 'at S², S³.
These signals and their operative mechanism may be of any of the well known
frames employed for such purposes, one of novel and efficient construction being
herein after described, in which the signal consists of two vanes or wings crossing
one another at right angles at their middle, where they are supported on a vertical

page_text: shaft intermittingly rotated one fourth a revolution to prevent the face of one or
the other of the said plates, which indicate safety and danger respectively.
The said plates are elongated in a horizontal direction, and are of different color
to enable them to be distinguished from one another; they are also preferably
somewhat different in form as a further distinction, one, for example, having large
circular openings at each end.
By means of an organization of electric circuits, which will be herein after
explained, a locomotive or train entering upon the signal section A at the end
nearest the signal S, causes the said signal to assume a position with its colored
vane (signifying danger) at right angles to the line of the track, and the signal
will remain in this position as long as the train occupies any portion of the
signal section.
The action of the signal is also continued by means of special devices for that
purpose, while the train is passing over a certain portion of the next adjacent
section ahead.
Therefore if any accident should occur which should stop a train just after it had
entered upon a signal section, a following train will be warned, not alone by the
signal of that section which may be too near to enable the following train to be
stopped in time, but in addition by the signal at the entrance of the first named
section a mile or more farther back.
The manner in which this result is affected will be explained by reference to the
diagrams Figures 1 and 2, and it may be stated that the apparatus about to be
described in connection with one signal section is similar to that upon all the other
signal sections, and that the same arrangement is duplicated for a double track rail
road.
The signals S and Ss may be constructed in the manner herein before referred
to, or they may be of any other suitable or convenient construction.
The signals may be actuated directly by the armatures a² and a³ of the electro
magnets M2 and M³, or by trains of wheels driven by weights or springs and
controlled by the armatures, as herein after described, or in any other well known
manner, the only essential condition being that the mechanism shall be so con-
trolled by the electro magnet as to exhibit a safety signal whenever the said
magnet is in a magnetic condition, and a danger signal whenever the same is
demagnetized.
The pair of opposite lines of the rails of the signal section A2, A2, are insulated
from those of the adjacent sections at each end thereof, by means of suitable
insulated splices C and C³, the construction and arrangement of which are well
understood, and need no detailed description in this place.
Additional insulated splices D are inserted in both lines of rails at some suitable
intermediate point of the signal section, whereby each signal section is divided
into two sub-sections constituting two complete circuits, which are electrically
independent of each other.
At the left hand or forward end of the signal section A2, A2, is placed a battery B²,
the opposite poles of which are connected by conductors 2, 3, with the respective
lines of rails 4 and 5, while at the other or rear end of the forward sub section the
terminals 6, 7, of the electro magnet M¹ are connected with the respective lines of
rails in a similar manner.
Each line of rails is connected together at the joints so as to form a continuous
electric conductor extending from one end to the other of each sub-section.
The corresponding battery of the adjacent signal section is shewn at B¹ arranged
in the same way.
A circuit breaker E, controlled by an electro magnet M4, is placed in the circuit
of one of the conductors connecting the battery B2 with the lines of rails 4 and 5.
The remaining sub section of the signal section A2, A3, is also provided with a
battery B connected to the opposite lines of rails 8, 9, at the rear end of the
sub section, while at the forward end thereof the terminals of the electro
magnet M5 are connected with the said respective lines of raile, so as to form a

page_text: continuous and unbroken circuit at all times through both rails of the subsection
from the battery B³ to and including the electro magnet M5.
The circuit breaker E of the section A is kept closed by an electro magnet M*,
which is itself controlled in like manner by the apparatus of the adjacent signal
section A³.
In like manner the circuit breaker E¹ of section A¹ is controlled by the electro
magnet M, which is itself controlled by the apparatus of section A² in a manner
which will now be explained in detail.
A voltaic battery B¹ of sufficient power to actuate or control the signal by means
of the electro magnet M² has one pole (for example, the negative pole), connected
by the wire 10 with a circuit breaker F, which is kept closed so long as the
magnet M5 is in a magnetic condition.
From the circuit breaker F a branch wire 11 leads to the wire 12, which is
connected with one terminal of the electro magnet M. The other terminal of this
magnet is connected by wire 13 with the other pole of the battery B.
Another branch 14 leads from the wire 12 to the circuit breaker G, which is kept
closed by the electro magnet M' when the latter is in a magnetized condition; and
from this circuit breaker G the wire 15 leads to one terminal of the electro
-magnet M², the other terminal of the latter being connected by a wire 16 to the
positive pole of the same battery B'.
The corresponding battery B³ of the adjacent section is arranged in a similar
manner.
When the apparatus is in its normal condition and no train is on either of these
signal sections, as shown in Figure 1, each subdivision of the signal section A forms
a continuously closed circuit.
The electro magnet M' is charged by a current from the battery B³ which passes.
over the wire 2 through the line of rails 4 and wire 7 to electro magnet M², thenco
by wire 6, line of rails 5, wire 3, circuit breaker E, and wire 17 to the other pole
of the battery B³.
In like manner a constant current from the battery B2 traverses the wire 18,
line of rails 9, wire 19, clectro magnet M³, wire 20, line of rails 8, and wire 21.
Thus the electro magnets M and M are normally kept in a continuously
magnetic condition, hence the circuit breakers F and G are kept closed, and con-
sequently both the secondary branch circuits from the battery B, which respectively
include the electro magnets M³ and Mº, are also kept closed.
The effect of this arrangement is that the signal S² is maintained in a position
indicating safety-by-the-electro-magnet-M³,-while-tho-circuit-breaker_EL_is_also_
closed, thus maintaining the continuity of the circuit on the adjacent section A¹.
The circuit of the battery B2 of the section under consideration is closed in like
manner by the electro magnet M' of the succeeding section, and so on throughout
the entire series of signal-sections.
This arrangement therefore constitutes a series or chain of normally closed
signalling circuits, each circuit covering one sub-section.
There are two sub sections in each signal section, and therefore there as twice as
many signalling circuits as signal sections.
A circuit breaker is placed in each alternate signalling circuit of the series as at
F and E, and these circuit breakers are placed under the control of electro magnets
included in the adjacent intermediate signalling circuit.
Thus the circuit breaker E' is controlled by the electro magnet M5 of the
adjacent circuit, and the circuit breaker E by the electro magnet of the next
circuit of the series not shewn in the Figure.
Thus it will be understood that an interruption of the constant current of either
the batteries B2, B3, B4, will cause the electro magnet M³ to be demagnitized, and
the signal S' to be placed in a position denoting danger.
Such interruption might occur from a failure of one of the batteries to act
properly, or from the breakage of a wire or one of the rails of the track, the
removal or displacement of a rail, or any similar cause.

page_text: danger.
uny
sigual is necessarily assume a position indicating
The manner in which the signals are successively actuated by a moving train is
as follows:
Referring to Figure 2, let it be assumed that a train has entered upon the signal
section A2 A2, and occupies the position indicated by the dotted lines at H, or any
position between the insulated spices C and D.
'
The wheels and axles of the train constitute a moveable circuit closer, which has
practically no electric resistance, and which forms a connection between the two
opposite lines of rails of the tract.
.
The current of the battery B³ will now be diverted from the electro magnet Ms,
and will pass across at H from the rail 8 to the rail 9, the electro magnet M5 will be
demagnetized, breaking the circuit of the electro magnet M². at F, which will
thereupon become demagnetized and a danger signal exhibited at S2, as shown in
Figure 2, thus guarding the entrance to the section A2 in the rear of the train.
The circuit of the electro magnet M is also interrupted at the same instant by
the circuit breaker E, thus releasing the circuit breaker E¹ and breaking the signal
circuit of the rearward section, and exhibiting a danger signal at the entrance of
that section also.
This latter signal will continue to be exhibited until the train H has passed
wholly beyond the insulated splices D, as indicated by the dotted line H', when a
connection will be formed in the manner hereinbefore described between the.
rails 4 and 5.
The current of the battery B³ will now be diverted from the electro magnet M!,
which will become demagnetized and release the circuit breaker G, thus inter-
rupting the circuit of the electro maguet M² at the point G before it is closed at
the point F, which latter operation cannot take place until the entire train has
passed beyond the point D.
:
The closing of the circuit at F actuates the electro magnet Me, and thus restores
the safety signal at the entrance of the rearward section.
By a repetition of the above described series of operations upon the succeeding
signal section A³, the danger signal at S2 will continue to be exhibited in like
manner until the advancing train has reached the point corresponding to D on the*
advance signal section A³, when it will be restored to a position indicating safety.
Thus it will be understood that the danger signal of each signal is automatically
exhibited during the passage of a train over that section by reason of the
successive shunting and the consequent demagnetization of the electro magnets
M5 M6, and that the exhibition of a danger signal is continued during the passage
of the same train over a certain portion, viz., the adjacent sub section of the next
signal section ahead, in consequence of the interruption of the circuit by means
of a circuit breaker controlled by the train while traversing the last named sub
section.
The insulating splice D may be placed at any desired point between A² and A³,
according to circumstances.
In practice it is usually preferable to place it at a distance from the point C
at the entrance of the section, which is equal to the maximum distance required
in order to stop a train which has passed the signal S2 at full speed, and therefore
the proper distance will necessary be determined by the circumstances of the
particular location.
The spirals S S³, and so forth, are preferably operated by a mechanical motor,
such as illustrated in Figures 3 to 14 inclusive, it consisting essentially of a train
of wheel work actuated by a weight or spring to turn a shaft upon which the
signal disks are placed.
The movement of this shaft is regulated to cause the proper indications to be
given by an electro magnet M corresponding to the ones marked M² M³ herein
before described.
The blow of the moving parts of the signal when stopped after a change of
•

page_text: position is properly combined to prevent too great a shock, and the stops by which
the movement is arrested and permitted to again take place are not controlled
directly by the electromagnet, but by detaching devices controlled thereby and
arranged to have but slight force in acting upon the armature lever, but to
develop a greater force in their movement when released thereby, and before
reaching and acting upon the said stops.
The signal indicates danger when the magnet is demagnetized, and mechanism is
provided which operates automatically to show and retain the signal at danger
when the motor needs rewinding.
It consists of a circuit breaker in the main circuit connected with the actuating
mechanism, and operated thereby to open the circuit, demagnatize the magnet, and
set the signal to danger before the actuating power is quite exhausted or run
down, the circuit thereafter remaining open, and the signal indicating danger
until the actuating mechanism is again wound up.
Referring to the Drawings, Figures 3 to 14, the main driving shaft b, provided
with a pin b¹ to be. engaged by a key, and with a chain pulley b² to be engaged
by a chain passing over it and sustaining at one end, the actuating weight has
secured upon it a ratchet 63, the teeth of which engage a pawl connected with the
driving gear bloose on the main shaft 6, thus causing the said gear to turn with
the said shaft in its movement produced by the weight in descending, but allowing
the said shaft to be turned by the key to wind up or raise the said.weight without
turning the gear b in the usual manner.
The gear meshes with a pinion on a horizontal shaft c provided with a
bevel pinion c¹, engaging a bevel gear d with an equal number of teeth on a
vertical shaft, provided with a socket d², see Figure 3, to receive the stem d³ of
the signal proper S.
It will be seen that the horizontal shaft C and the vertical or signal carrying
shaft d' thus have an equal angular movement, and the former shaft c is provided with
four detent arms e, i, d², ds, which are adapted to be stopped in succession by the
detent mechanism hereinafter described, the shafts c, d, turning a quarter revolution
after one of the said arms is released, and then being stopped by the engagement
of the following arm.
The vertical or signal shaft d¹ is also provided with four arms & inclined at
their under sides, as shewn at 22, one of which at the end of each movement in
the direction of the arrow, Figure 5, passes over the projection 23 of the spring
catch, which engages the rear side of the said arms and prevent any backward
-rotation-or-recoil-of-the-signal-at-the-end-of-its-movement,-and-since-the-forward-
movement of the signal is prevented by one of the stops that engage the detent
arms, as hereinafter described, the signal is positively locked and prevented from
being turned by any outside agency, such as the pressure of the wind.
The detent mechanism by which the horizontal or detent shaft c is stopped at
the end of each quarter revolution in which the signal has been turned to present
a new face, is controlled by the electro magnet M and its armature a mounted on
the armature lever A, pivoted at 24, and provided, with two projections 25, 26, one
on either side of the said lever, to engage catches 27, 28, on the detaching arms
g, g', pivoted at 29 on the framework.
The armature lever lies in about the same plane with the detent arms, and there
are two corresponding sets of devices, one set to permit the signal to move from
the safety to the danger position, and the other set to permit the movement from
the danger to the safety position, the corresponding devices of the two sets being
situated on the opposite faces (front and rear) of the said armature lever and
detent arms.
When the armature is in one position as attracted to the poles of its magnet, as
in Figure 3, the projection 26 is in position to engage the catch 28 of the safety
detaching arm g¹, holding its weight nearly vertically above its pivotted point 29,
as shown in Figure 3, while the projection 25 is not in position to engage the
catch 27 of the danger detaching arm g, which is thus allowed to turn on its

page_text: pivot 29 under the action of the weight g* until its heel or short arm 30
engages a pin 31 on the hook shaped stop h, raising it out of the line of
movement of the stop pins 32 on the front face of the danger detent arms e', e³;
the said detaching arm g when thus allowed to fall having raised the stop arm h
from engagement with the pin 32, and allowed the shafts c and d to turn a quarter
of a revolution until one of the stop pins 33 on the rear face of the safety detent
arms is engaged by the safety stop h', as shewn in Figure 3.
In this rotary movement, permitted by the falling of the arm g, as thus
described, a raising pin 34 on the rear face of the danger detent arm e³ engages the
toe 35 of the safety detaching arm g', then in the position shewn in Figure 4, and
raises the said arm to its nearly vertical position, Figure 3,. when the catch 28 will
be engaged by the projection 26 to retain the arm in this position.
The rear end of the armature lever A with its projections 25, 26, is elevated and
placed in line with the catch 28 on the arm g¹ before the said catch is brought by.
the action of the raising pin 34 on the toe 35 of the said arm into engage-
ment with the said projection, and the said catch 28 has to be moved wholly
past the said projection before being engaged thereby to prevent its return
movement.
To do this either the projection 26 or the catch 28 must yield, and the said catch
is pivotted at 36 and turns thereon to allow its engaging end to pass fréely by the
projection 26 in the upward movement of the said arm, and when past the said
projection it drops down under the action of a spring into line therewith, and is
engaged thereby to prevent the backward movement of the said arm.
When the parts are in the position shown in Figure 3, and the magnet is
demagnetized, the armature lever by its own weight drops upon the stop pin 37,
the projection 20 thereon in the said movement being disengaged from the catch 28
of the detaching arm g¹.
The said detaching arm is thus left free to drop under the action of gravity, and
at the end of its movement the heel 38 thereof strikes the pin 39 of the hooked
safety stop h, raising it from the pin 33 projecting from the rear face of the upper
safety detent arm, thus leaving the shaft free to rotate.
In the rotation of the shaft c the raising pin 40 on the front face of the said upper
safety detent arm engages the toe 41 and raises the danger detaching arm g until
its catch 27, passes the projection 25 of the armature lever A, the sides of the
projection and catch that meet in this movement being rounded so that the
projection is readily moved to allow the catch to pass the armature lever being
lifted and then falling when the catch has passed the projection 25, so that when
the arm g is disengaged from the pin 40 and begins to fall back, the squared faces
of the catch and projection engage and stop the said arm until the said armature
lever is again moved by a change in the condition of the magnet.
While the arm g is thus raised its heel 30 is moved away from the pin 31 of
the danger stop h, allowing the said stop to fall upon the pin h2, it being assisted
in this movement by the spring h³, and the hooked end of the said stop is thus
brought in line with the stop pin 32 on the danger detent arm e¹, which strikes the
said hook and is stopped thereby, the shaft c having made a quarter revolution and
the signal S turned to present a different face.
A pin 43, covered with rubber or similar cushioning material, receives the weights
when they first drop, and after the shaft c has made its quarter revolution they
remain at rest with their toes 35, 41, resting against one of the pins 34, 40, as
shewn in Figure 3, ready to be elevated thereby when the machine is released by.
the other weight falling.
It is desirable to have the actuating weight very large in order that the signals
shall be turned very promptly upon the change of condition of the magnet M, and
as the signal arms are of considerable weight the moving parts of the apparatus
have acquired a considerable momentum at the moment when the stop pins 32, 33,
meet their corresponding stops h, h¹, so that if these stops were rigidly connected

page_text: with the frame work, and this momentum suddenly checked, a severe strain would
be brought upon the different parts of their apparatus which would soon wear it
out or destroy its effectiveness.
To obviate this the said stops are connected with the frame work by a cushioning
device by which the momentum is gradually overcome without causing a sudden
shock to the machine.
As herein shown the stops h, h¹, are pivotted at 43 upon the short arm of a lever
i, itself pivotted at 44 to the frame work, and provided at the extremity of its long
arm with a cushioning device shown in Figures 3 and 13 as a spiral spring i¹,
inclosed in a cylinder connected with the said arm, and pressing at one end
against the cylinder and at the other end against a pin 2 moveable in the said
cylinder, and bearing against a projection rigidly connected with the frame
work.
When the pins upon the detent arms strike the stops they cause the lever i to
turn on its pivot 44, moving its lower end towards the projection ³, the pin
being prevented from moving by the said projection, so that the lever i in this
movement bears against and compresses the spring and is gradually stopped
thereby instead of bringing up suddenly against a fixed point.
In Figure 14 a dash pot or air cushion is used instead of the spring, the pin i²
having a piston connected therewith that fits closely in the cylinder at the end
of the lever i, and the air of 45 within the said cylinder performing the function
of the spring previously described.
In order that the actuating power may not become exhausted when the signal is
in its safety position, so that it will not be moved to indicate danger at the proper
time, the circuit of the electro magnet M is in this instance controlled by a circuit
controller operated by the running mechanism to put the said magnet in the
condition to give the danger signal, that is in this instance, to demagnetize it, and
as the said magnet will thereafter be controlled by this circuit controller and not
by any extraneous parts, its condition cannot thereafter be changed to release
the detent arms and allow the mechanism to display a different signal.
The signal will therefore remain indicating danger until the circuit controller is
again operated as by the winding of the machine.
This circuit controller consists of two springs j, j¹, insulated from one another
except at their extremities 46.
The former is connected with the wire 47 and the latter with the wire 48, by
which the circuit is continued from the binding screw / to the coils of the magnet
M, connected at their other terminal by the wire 49 with the binding screw ', so that
when the extremities 46 of those springs are separated from one another the circuit
of the said magnet is broken.
The main winding 6 is screw threaded for a portion of its length, as shewn at 50,
and a nut mounted thereon and prevented from turning by a guide ', fitting a
grove 2 in the said nut, so that as the shaft turns under the action of the weight
actuating the machine or key in winding it the said nut has a longitudinal move-
ment thereon.
A projection of insulating material on the side of the said nut extending out
between the springs j,j, comes at the end of its movement outward from the body
of the machine caused by the machine running down between the ends 46 of the said
springs, thus separating them and breaking the circuit of the magnet which there-
after remains demagnetized, so that after the signal has come to its danger position
corresponding to this condition of the magnet no further movement can take place
until the signal is again wound, when the nut 7 is moved back and the ends 46 of
the springs j, j, again come in contact with one another, closing the circuit at this
point so that the magnet is thereafter controlled by the wheels of the passing train
and other circuit closers outside of the machine in the usual manner until it again
runs down.

page_text: The form of signal preferably used is illustrated in Figures 10, 11, and 12, consists
of a strong metal frame piece m, having four arms extending at right angles to one
another, as shewn in Figure 12, upon which are rivetted the wings m', m², the signal
post being placed so that one of the said wings is perpendicular to the line of rail-
way indicated by the arrows m³, Figure 12, when the machine is stopped by the
detent mechanism herein before described, the other of the wings being at this time
parallel to the line of railway so that only its edges is presented to the view of
one approaching the signal along the line of railway, the said wing being so thin
that its edge is not noticeable to the eye.
The discs m, m2, may be distinguished from one another in any usual way, as
by their color, the one indicating danger, being preferably red in color, as is usual
in danger signals.
They are in this instance also further distinguished by their shape, the one m¹
being wider at its ends and having circular openings, therein as at m*, while the
other is narrower and has no such opening.
Figures 16, 17, and 18 represent the interlocking mechanism which is employed
for the purpose of actuating the switches and siguals for indicating the position of
the same to the engineer of an approaching train.
The moveable switch rails are secured in their normal position, that is to say, in
line with the main track, by means of a locking apparatus actuated by a suitable
hand lever which is so arranged with reference to the lever by which the rails of
the switch are moved and to the mechanism for actuating one or more signals as
to render it impossible for the switchman to unlock the moveable rails without first
placing the distant signal or signals guarding the main line in position to indicate
danger to an approaching train, and moreover that, as soon as the switch rails shall
have been moved ever so little out of line with the rails of the main track, it shall
be impossible to restore the said distant signal or signals to a position of safety
until the said rails have been again moved back into line with the main track and
securely locked in that position.
The moveable rails R, R, of the switch are pivotted at one end, as shown at
51, while their opposite ends are free to move upon the chairs or head blocks I, I,
into line with the rails 4, 5, of the main track or the rails R¹, R', of the branch.
track or siding having their ends securely fastened in the said head blocks.
The moveable rails R, R, are held parallel to each other and at a fixed distance
apart by means of a connecting bar or bridle J, which is firmly secured to both of
the rails by bolts or otherwise, as shown in Figure 16.
"
The rails of the track both fixed and moveable are supported upon a series of
cross ties or sleepers.
An upright frame or switch stand K is secured by bolts or otherwise to the said
sleepers and the levers for moving and locking the switch are attached thereto.
The shifting of the moveable rails from the main track to the side track, and
vice versa, is effected by means of a crank lever L, which is provided with a
handle L, and which is secured to an upright shaft L, the latter being secured to
the frame K by mounting it in suitable journals or bearings at its upper and
lower ends.
The short crank arm L³ projects at right angles from the lower end of the
upright shaft L' at a point at or near the horizontal plane of the moveable rails
R, R, and a pitman rod L is pivoted at one end to this crank arm and at the
other to the bar J, see Figure 16.
A lug or staple N is affixed to the switch stand K which enters into and passes
freely through a corresponding slot in the arm L, when the latter is in its normal
position, as shown in Figure 10.
This arrangement enables the lever to be securely fastened in its normal
position by means of a pin or padlock N', which is passed through the eye of the
lug or staple N, as shewn in Figure 16.
The manner in which the switch rails are shifted by means of this mechanism
will be hereinafter explained.

page_text: their normal position, the toes 0 are free to enter into the recesses 52, and thus
lock the switch rails in position.
This latter movement is preferably effected automatically by means of a spring P²
attached to the lever P.
By the same operation the danger signal at the distant point is reversed and
withdrawn so as to denote safety to an approaching train.
It will be understood however that this movement of the signal cannot be effected
until the moveable rails have been locked in their proper position by the toes (2,
for until this operation has taken place the lever cannot be brought to an upright
position.
Owing to the peculiar construction of my improved locking apparatus, it is not
possible for the switch rails to be unlocked, much less moved from their proper
position, without the previous exhibition of a danger signal upon the main line at
a sufficient distance to warn an approaching train of the condition of the track.
If by any accident the switch stand and the apparatus connected therewith should
be entirely carried away or destroyed, as by an accident occurring to a passing
train, the switch rails would still remain locked and the position of the track would
be maintained.
It is obvious that the signal employed in connection with my Invention might
be mechanical instead of electrical.
In such case a chain or cord could be connected with the lever P and extended
to and properly connected with the signal to operate it when the said lever was
moved to lock and unlock the switch rails.
In some instances it is desirable to actuate the signal by the direct action of
magnetic force instead of by a mechanical motor, as herein before described, as in
the case of a small indicating signal, to show to the signal men the condition of
the main signal at a distant point, the said indicating signal being controlled by a
circuit closer operated by the said main signal.
The principal feature of this magnetically actuated signal consists of an electro
magnet provided with a peculiarly constructed armature which is furnished with
one or more wings or blades rotating upon an axis which is parallel to the cores of
the electro magnet and perpendicular to the face of its poles, each of said wings
forming a section of a disc, of which the said axis is the centre, and presenting
an inclined or helical surface to the pole or poles of the electro-magnet.
Each of said wings or blades is also preferably horizontally tapered so as to
present a surface of constantly increasing breadth to the magnetic pole when .
moving towards it and across the magnetic field.
The signal disc is connected to and moved by the said armature, which is provided
with two detents controlled by an independent armature, one of which locks the
armature and signal disc when the latter is in a displayed, and the other when it is
in a concealed position.
The Invention further consists in actuating said electro magnet by a battery
composed of two sections, and in combining with the armature of said electro
magnet a circuit changer actuated by the movements of said armature, which acts
to disconnect one section of the battery from the circuit which passes through the
electro magnet at or before the time when the signal disc has been brought in its
displayed position.
In Figures 20, 21, and 22 of the Drawing, M is an electro magnet of the usual
horse-shoe form, which is preferably mounted in an upright position upon a base W,
as shewn in the Figure.
The parallel cores of the electro magnet M are connected together by a soft iron
yoke mx in the usual manner..
The soft iron armature of the electro magnet M is mounted upon an upright
shaft or axis n, which turns in a step bearing in the yoke m*.
The armature a is of a peculiar form, being composed of a section of a horizontal
disc or plate having the axis n in its centre.

page_text: It is formed into two wings or blades p and p', which are preferably horizontally
tapered towards their extremities, as best seen in Figures 21 and 22.
The lower surface of the wings and p is of a helical form, being inclined to
the plane of the horizontal faces of the magnet poles q, q':
The points of the wings are at the greatest vertical distance from the horizontal
plane of the pole, and the central portion of the armature nearest it.
This is best seen at p, p, in Figure 20, which represents the apparatus in the
same position as it is shown in Figure 22.
It will therefore be understood from the above description that when an electric
current traverses the coils of the electro-magnet, its poles q, q', Figures 20 and 21,
become magnetic, and exert their attraction simultaneously upon the extremities
of the wings p and p¹ of the armature a, and tend to cause it to revolve horizontally
upon its vertical axis n in the direction indicated by the arrows, and this effect
will continue so long as the electric current flows, or until the armature a has been
brought into the position in which it is represented in Figure 22.
The strength of the magnetic attraction between the poles q and q¹ and the
wings p, p, of the armature constantly increases as the latter moves across the
magnetic field, for the reason that the mass of the armature which is within
the attractive sphere of each magnetic pole gradually becomes greater as the
broader part of the armature comes into its vicinity, and moreover in consequence
of its inclined form the mass is brought nearer and nearer to the pole of the magnet
as the armature revolves.
By reason of this peculiar form of construction I am enabled to produce a
horizontal rotation of an armature in a plane perpendicular to the axis of the cores
and parallel to the face of the poles by the direct force of magnetic attraction
without any intermediate mechanism, a result which is of great importance in the
application of an electric-magnet to the movement of visual signals, and other
devices of like character.
:
It will be seen that the axis n, upon which the armature a is mounted, moves
through the distance of one fourth of a complete revolution during the operation
which has been described.
When a visual signal is designed to. be operated by this mechanism, a suitable
signal-disc or target S is mounted upon the shaft n, as shown in the Figures.
It will be readily understood that by turning the shaft n through the distance
of one fourth of a revolution the target will be placed at right angles to its former
position so as to give a different indication.
-For-example,-when-employed-as-an-indicating-signal,-the-position-shown-in-
Figure 21 may indicate that the main signal is at " danger," while that shewn
in Figures 20 and: 22 may in like manner indicate that the main signal is at
"safety."
When the apparatus is employed in this manner to operate a visual signal it is
preferable that means should be provided whereby the signal may be securely
locked in each of its two positions.
This is effected by means of a supplementary or independent armature (best
seen in Figure 21) mounted upon a pivot at 53 upon a stationary plate r, which
may be supported by the electro-magnet M or otherwise.
The arm & projects at right angles from the pivot 53, and carries a latch or
detent s¹, which takes hold of a pin s upon the upper surface of the armature a
by virtue of the tension of the spring s³.
Z is another spring detent or latch which is also attached to the supplementary
armature ax, but upon the opposite side of the pivot 53.
It will be understood therefore that when no current is traversing the coils of
the electro-magnet M, the supplementary armature ax and its attachments will
remain in the position shown in Figure 21, the latch or detent s¹ being engaged
with the pin s².
This prevents any motion of the armature a in the direction indicated by the

page_text: arrows, while at the same time its motion in the opposite direction is limited by
the pin 54 on the under side of the armature resting against a fixed stop 8*, which
may be attached to the plate r, as shown.
So soon however as the electric current traverses the electro magnet M, and the
pole q' becomes magnetic, the armature aª is attracted and brought into contact
with it, which withdraws the detent s' and releases the pin 82 on the armature a,
so that the latter becomes free to obey the attraction of the magnet M, and .move
into the position shown in Figure 22.
When it reaches this position, a downward projection t upon the armature
brings up against the pole q of the electro-magnet, and the movement of the
armature is thereby arrested, while at the same time the detent Z, by reason of
its elasticity, drops in behind the rear corner of the armature a, as seen in
Figure 22, and thus securely locks it in its now position.
When the current through the electro-magnet M is interrupted, the detent Z is
withdrawn from the path of the armature a by the action of the spring 9³, and
the armature then becomes free to return to its normal position by the action of a
retracting spring t¹, the tension of which may be adjusted in the usual manner by
means of a suitable adjusting screw or pin t2.
When the armature a and signal target S have been brought by the action of
an electric current of sufficient power into the position represented in Figure 22,
it will be obvious that a much smaller attractive force will be entirely sufficient
to retain the armature and signal in position, it being only necessary that the
attraction should be sufficient to keep the supplementary armature and its detent
from falling back, thus avoiding the unnecessary consumption of battery power
which must otherwise ensue in case the signal is required to be held in position by
a constant current for the greater part of the time, as is frequently the case in
practice.
It is preferable to make use of a device whereby a section of the battery is
disconnected from the electro-magnet which actuates the signal as soon as the same
is brought into position.
This is effected by means of a commutator or switch which is operated by the
armature itself.
u, u, u, are three metallic springs mounted upon suitable supports u³ which
serve to insulate them from each other.
The middle spring u¹ is considerably longer than the other two, and is so adjusted
that when in its normal position of rest it will press against the spring u (as
shown in Figure. 21) by virtue of its own resiliency.
The pin is placed upon the upright shaft n, and is so situated with reference
to the projecting end of the spring u' that when the apparatus moves into the
position shown in Figure 22, the pin will press against the extremity of the
spring u¹ and separate it from contact with the spring u, at the same time pressing
it into contact with the spring u³, whereby the necessary change in the electrical
connections is effected.
The battery connections are shown in Figures 20 and 21 by means of a skeleton
diagram.
The battery B10 is composed of two sections 610 and 61%, and one of its terminals
is connected by the wire 60 with the spring u.
The other terminal of the battery is connected by the wire 61 to a key or other
circuit closer, such, for example, as the one shown at K10 in Figure 21, from which
a wire 62 goes to the binding screw 63 which is connected with one terminal of
the electro-magnet M by means of a wire 64.
The other terminal 65 of the electro magnet goes to the binding screw 66 which
is connected by the wire 67 with the spring u¹.
Finally, the spring us is connected by means of a wire 68 to a point between the
sections 610, 62, of the battery.
The result of this arrangement of circuit is that when the signal armature has
been brought into position (shown in Figure 22) the portion of the battery

page_text: represented by 610 is disconnected, and only the portion 612 remains in action to
hold the signal in position.
A very efficient apparatus of this kind for some purposes may be constructed
with an electro-magnet having but a single helix and core, in which case the
armature may have but a single wing or blade, or it may be provided with two
wings at opposite ends of the core facing its respective poles.
The principle of operation in these modifications remains the same as in the
apparatus herein before described.
Having now described and particularly set forth the nature of the said Invention.
and the manner of carrying the same into effect, I would have it understood that
what I claim is,---
1st. The combination, substantially as hereinbefore set forth, of a scries of
normally closed railway signaling circuits, each of said circuits including a battery,
an electro-magnet, and a section of insulated railway track forming part of said
circuit between the battery and the electro-magnet, with circuit breakers placed in
each alternate circuit of the series and not in the intermediate circuits, each of
which circuit breakers is controlled by an electro magnet included in the adjacent
intermediate circuit.
2nd. The combination, substantially as herein before set forth, of a series of
normally closed railway signaling circuits, a circuit breaker placed in each
alternate circuit of the series which is controlled by an electro-magnet included
in the adjacent intermediate circuit, and a series of electro-magnets for actuating
signals, each of which is under the control of three successive signalling circuits.
3rd. The combination, substantially as hereiebefore set forth, of a secondary
.circuit for actuating an electro-magnet controlling the movements of a signal, two
independent circuit breakers placed in said secondary circuit, and two independent
primary signaling circuits respectively controlling the action of the said circuit
breakers, which primary circuits are themselves actuated successively by a train
while traversing the signal section protected by said signal.
.
4th. The combination, substantially as hereinbefore set forth, of two independent
primary signalling circuits which are acted upon successively, by a train while
traversing a signal section, two independent circuit breakers controlled respectively
by the said primary circuits when so acted upon by the train, an electro-magnet
for actuating a signal which is included in a secondary circuit under the control of
both of said circuit breakers, and an electro-magnet for actuating the signal of an
adjoining signal-section which is included in a secondary circuit under the control
-of-one-of-said-circuit-breakers,-but-not-under-the.control.of.the.other..
5th. In a railway signal apparatus the motor to set the signal in different
positions and the detent mechanism therefor, consisting of the following elements,
viz., the detent arms and stops therefor combined with detaching arms, one to
disengage each of the said stops, and the electro-magnet and its armature adapted
to engage and arrest the movement of one only of the said detaching arms when
attracted, and the other of the said arms only when unattracted, substantially as
and for the purpose described.
6th. The motor and its safety and danger detent arms and two stops, one to
engage the said safety and the other to engage the said danger detent arms combined
with two detaching arms and an electro magnet and its armature to control them,
it being adapted to hold only one of the said arms at one time, the said devices
being arranged to operate as described, whereby when the condition of the magnet
is changed one of the said detaching arms is released to detach one of the stops and
allow the motor to move and change the position of the signals, substantially as
described.
7th. A motor and detent shaft and detent arms thereon and two stops each to
engage an alternate pair of the said arms combined with two detaching arms, one
to disengage one and the other to disengage the other of the said stops from its
corresponding detent arm, and restoring devices operated by the motor in its
movement, whereby when one of the said detaching arms is operated to allow the

page_text: motor to move, the other of the said arms is restored to the position from which
it can operate to again release the notor and permit it to move, substantially as
described.
8th. In a railway signal apparatus a signal and motor to set it in different
positions, and an electro-magnet to control the said motor, combined with a circuit
controller in circuit with the said magnet operated by the said motor when nearly
run down, whereby the magnet is retained in one condition, and the danger sigual
remains permanently displayed until the motor is wound up, substantially as and
for the purpose described.
9th. In a railway signal apparatus, a detent shaft turning uniformly with
the signal shaft, and having detent arms corresponding to the safety and danger
position of the signal, the said arms being provided with stop pins, those of the
safety arms being on the side thereof opposite to those of the danger arins combined
with safety and danger stops to engage the said safety and danger pins
respectively, and detaching arms to disengage them therefrom, each of the said
detaching arms being held by the armature of the electro-magnet while the corre-
sponding stop is engaging its pin in position to operate upon and disengage
the said stop as soon as the condition of the magnet is changed, substantially as
described.
10th. The main winding shaft of the motor, screw threaded, and provided with
a nut and a device to prevent the said nut from rotating with the said shaft, com-
bined with an electro-magnet to control the operation of the said motor and circuit
closing springs in circuit therewith and adapted to be separated by the said nut to
break the circuit when the nut is near the end of its movement along the main
shaft caused by the rotation of the said shaft in actuating the machine, substantially
as and for the purpose described.
11th. The combination with a mechanically moved signal of a detent or stop
therefor, and a cushioning device interposed between it and the frame work
whereby the signal is gradually stopped without shock to the parts, substantially
as described.
12th. The combination, substantially as hercinbefore set forth, of the movable
rails of a switch, a rigid bar or rod connecting the same with each other, a lever
for moving said rails, movable toes situated between the movable rails for locking
said connecting bar and rails in their normal position, and independent mechanisın
for moving said toes for the purpose of locking and unlocking the switch rails.
13th. The combination, substantially as herein before set forth, of the movable
rails of a switch, a rigid bar or rod connecting the same with each other, a lever for
moving said rails, movable toes situated between the movable rails for locking said
connecting bar and rails in their normal position, an independent lever for moving
said toes, and means operated by the said independent lever to control or operate
the distant signal.
14th. The combination, substantially as hereinbefore set forth, of the movable
rails of a switch, a rigid bar or rod connecting the same, a lever for moving said
rails, movable toes for locking said connecting bar and rails in their normal position,
an independent lever for moving said toes, means for operating or controlling a
distant signal, and a bolt for securing said independent lever which is actuated by
the switch lever when fastened in its normal position.
15th. The combination, substantially as herein before set forth, of an electro-
magnet and an armature which moves towards and from its poles in a plane
perpendicular to the axis of the cores and parallel to the face of the poles of said
clectro magnet, and which is horizontally tapered so as to present a surface of
constantly increasing breadth to the pole as it moves toward it and across the
magnetic field.
16th. The armature of an electro magnet, constructed substantially as herein
before set forth, consisting of two wings or blades rotating upon an axis parallel
to the cores of the electro magnet which present an inclined or helical surface to
the respective poles of said electro magnet.

page_text: 17th. The armature of an electro magnet constructed substantially as herein
before set forth, consisting of two wings or blades rotating upon an axis parallel to
the cores of the electro magnet, each of said wings forming a section of a disc, of
which said axis is the centre.
18th. The combination, substantially as herein before set forth, of an electro
magnet, an armature which moves toward and from its poles in a plane per-
pendicular to the axis of the cores, and parallel to the face of the poles of said
electro magnet, a detent controlled by an independent armature which normally
locks the first mentioned armature in its position of rest, but is withdrawn by the
action of the same electric current which is employed to effect the movement of
the first mentioned armature.
19th. The combination, substantially as herein before set forth, of an electro
magnet, an armature which moves towards and from its poles in a plane per-
pendicular to the axis of the cores and parallel to the face of the poles of said
electro magnet, a detent controlled by an independent armature, which is held in
position to lock the first mentioned armature by the action of the same electric
current which effects the movement of the said armature and a spring which
withdraws the locking detent from the first armature when the second armature is
released.
20th. The combination, substantially as herein before set forth, of an electro
magnet, an armature, a signal disc mechanically connected to and moved by said
armature, a battery for actuating said electro magnet, which battery is composed
of two sections, and a circuit changer actuated by the movement of said armature
which disconnects one section of said battery from the electro magnet just before
the signal disc has been brought to its displayed position.
In witness whereof, I, the said William Morgan-Brown, have hereunto set
my hand and seal, this Twenty sixth day of August, in the year of our
Lord One thousand eight hundred and eighty one.