IM- PROVED ELECTRIC RAILWAY SIGNALLING APPARATUS
Year: 1875

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for the Invention of "IM-
PROVED ELECTRIC RAILWAY SIGNALLING APPARATUS."-A communication
from abroad by David Rousseau, of the City, County, and State of
COMPLETE SPECIFICATION filed by the said William Clark at the
Office of the Commissioners of Patents, with his Petition and
Declaration, on the 4th August 1875, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CLARK, of 53, Chancery Lane, in the County of Middlesex, Patent
Agent, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVED
ELECTRIC RAILWAY SIGNALLING APPARATUS," and have petitioned Her
Majesty to grant unto me, my executors, administrators, and assigns,

page_text: Declaration that it has been communicated to me from abroad by
David Rousseau, of the City, County, and State of New York, United
States of America.
NOW KNOW YE, that I, the said William Clark, do hereby declare
that the following Complete Specification, under my hand and seal, fully
describes and ascertains the nature of the said Invention, and in what
manner the same is to be performed in and by the following statement,
reference being had to the accompanying Sheet of Drawings, and to the
letters and figures marked thereon (that is to say) :-
This Invention relates to a new electric apparatus for operating rail-
road signals from two or more different points by means of a single
electro-magnet, so that when the circuit is established through said
electro-magnet by an approaching train or otherwise the same will
attract its armature and cause the signal to be displayed, while when
the circuit is again established by the same train after it shall have
passed the signal and reached the second instrument, or otherwise, the
electro-magnet will once more attract its armature and thereby cause
the signal to be moved out of sight.
The Invention is equally applicable to audible and visible signals.
As far as the portion of mechanism above referred to is concerned the
Invention consists, first, in providing the rotary signal stem or shaft with
projecting cams or pins, and in placing near the same two springs, which
are respectively connected with the two instruments at opposite sides of
the line in such manner that when one of these springs is in contact
with its cam of the stem the other spring will invariably be out of
contact, and vice versa.
The Invention also consists in placing on the metallic frame of the
signal, or at least in metallic connection with the signal and stem, an
electro-magnet whose one wire is connected with the battery from which
the power is derived. The armature of this electro-magnet serves as a
lock for projecting arms of the signal stem, clockwork being employed
to turn said stem whenever the lock is withdrawn from the said arms.
By this arrangement, of which the operation will be herein-after more
fully described, but one electro-magnet and one battery need be used to
operate the signal by approaching and receding trains from opposite

page_text: sides, or by other means, and the power of the battery may be
economized though insuring invariably the most perfect operation.
Another feature of the Invention has reference to the placing and
securing of the lamp in front of the signal, and consists in so locking
5 the frame or guard by which the lamp is confined to the signal support
that said frame cannot be opened or detached to allow the inscrtion or
removal of the lamp without first causing the winding up of the clock-
work by which the signal is operated. By such an arrangement the
proper operation of the clockwork is insured, as the lamp will have to be
removed at least once each day, and the clockwork therefore wound up
once during the same period. In order to effect this object various
means can be employed, but it is preferred to apply a gear wheel to the
clockwork, which when turned by the winding-up movement will carry
a pin against a lever that locks the lamp holder, and so swing said lever
as to permit the opening of the holder.
Another object of this Invention is to produce an instrument which
will enable the superintendent at a railroad station or depot to properly
control the movement of trains without being obliged to leave his
station or keep each train bodily in view. At stations where large
numbers of trains enter and leave a control of the movements of such
trains within a certain distance is absolutely necessary in order to pre-
vent collisions and delay, aside from the desirability of keeping a record
of the time kept by each train, and of its position at any one time. In.
this regard the Invention is based upon the proper utilization of the
oircuit closing devices, already applied to first-class railroads for auto-
matically setting the signals, by which the engineer of cach train
regulates his movements, but is also applicable to roads that do not
have such or other electric signals.
The principal feature of this part of the Invention is the application of
a vibrating index clapper to and between two gongs, so that said clapper
will by its position indicate the condition of a given section of the line,
while it will by contact with one of the gongs give notice of every
change of its position, and consequent change of the condition of the
line.
Another important feature of this part of the Invention has reference
to the mechanism for imparting motion to the index clapper by the
armature of an electro-megnet, which is composed of a lever suspended

page_text: from the index clapper over an arm of the armature, as herein-after
more fully described.
A further prominent feature of this Invention consists in the appli-
cation of projections or wings to the index clapper, which said wings
serve to close contact with the wires through which the currents that
cause the clapper to move are passed; thus the clapper after each
motion makes contact with a wire through which its position will be
reversed as soon as the current passes through such wire. In other
words the body of the index clapper is made part of the conductor of
cach current that affects the position of the clapper.
In the accompanying Drawings Figure 1 represents a side elevation,
partly in section, of the improved signal and block; Figure 2 is a top
view, partly in section, of the same.
Figure 3 is a detail face view of the wheel which moves the lamp
locking lever.
Figure 4 is a face view of the improved electric signal; Figure 5 is
a side view thereof; Figure 6, a top view of the same.
Figure 7 a detail top view of the armature attachment; and Figure 8
a detail side view showing the mechanism for locking the signal at the
danger position when any part of the apparatus is out of order.
Figure 9 is a face view of the improved station signal; Figure 10 is
a side view of the same.
Figure 11 is a vertical cross section of the same; and Figure 12, a
detail cross section of part of the index clapper and its attachments.
Similar letters of reference indicate corresponding parts in all the
Figures.
The letter A in the Drawing, with special reference to Figures 1, 2,
and 3, represents a stationary frame, on which the signal B is supported.
This frame is by preference placed on a post or pillar at such height
that the signal will be properly displayed at the requisite distances.
The signal B is mounted upon a vertical shaft or stem C which has its
bearings in the frame A, and which, by means of bevelled gear wheels a,
or otherwise, is in connection with a drum D, upon which a weighted
cord or rope E is wound, so that such drum, or an equivalent spring,
will have the tendency when wound up to rotate the signal on and with

page_text: its vertical shaft. This rotation is prevented by one of four more or less
radially projecting arms of the shaft C striking a lug d that projects
from the outer face of armature lever F. The armature is by means
of the spring e held away from its electro-magnet G and in such position
as to bring its lug d in the way of one of the arms of the shaft C.
Upon the shaft C are further mounted two projecting cams or ears
f and g. A non-conducting platform H, which is placed near the
shaft C, serves to support two springs h and i, which reach so near to
the shaft C, and are so placed that when the signal is in its hidden or
non-displayed position, which is shown in Figure 1, the spring h will be
in contact with the cam g, while the spring i will be away from the
cam f, as shown in Figure 2. When however the signal is turned to be
displayed the cam f will be in contact with the spring i, and the cam g
away from the spring h. The spring his by a wire ; connected with
an instrument which is placed at a suitable distance from the signal,
near the railroad track, in that direction from which the train which is
to operate the signal approaches the same. The spring is by a wire
connected with a similar instrument at the opposite side of the signal,
that is to say, on that side toward which the train recedes from the
signal. The electro-magnet G is by a wire m connected with the battery
from which the power for moving the armature F is to be derived. The
same battery is also connected with the two operating instruments
placed near the track.
Wherever a train approaches the signal it will upon reaching that
instrument, toward which the wire j is conducted by suitable mechanism
or means provided on that instrument or train, or both, close the circuit
through the wire j, instrument battery wire m, electro-magnet G,
metallic frame A, stem C, cam g, and spring h, so that by such closing
of the circuit the electro-magnet will be charged, the armature F
attracted, and the clockwork or drum D thereby liberated to partly
rotate the signal. As soon as, during such rotation, the cam g has left
the spring the circuit is broken and the armature immediately with-
drawn from the electro-magnet by the spring e, so that the next arm b
of the stem C will be retained by the lug d of the armature. In this
position then the signal will be displayed to the approaching train, or
to parties who are to be advised of the approach of such train. In this
position furthermore the cam f will be in contact with the spring i.
After the train has passed the signal and reached the second instrument

page_text: it will, by the mechanism there provided, close the circuit through such
instrument, battery wire m, electro-magnet G, frame A, shaft C, cam f,
spring i, and wire 1, and cause thereby the further attraction of the
armature, the further rotation of the signal, and the final placing of the
signal out of view.
The position reached after the motion last described will be the same
as that shown in Figure 2, with the exception only that the cam f will
then be in contact with the spring i, and the cam in the position
occupied by the cam fin Figure 2.
5
It is evident that the features of the Invention above described are 1
applicable to various kinds of signals, and I do not confine myself in
their use to the rotary signal herein described.
I is a frame or guard, by which a lamp that is used at night to show
the signal is held to the frame A. This guard I is removable to permit
the insertion and removal of the lamp, or if not removable is at least so 1
attached to the frame A. that it can be swung open and closed. When
closed a hook shaped projection n enters through an opening in the
frame A from said guard, and is locked by a lever J, which is clearly
shown in Figure 1. The lever J is so balanced on its pivot that it will
by its own weight lock into the hook n, as shown. The inner end of 2
the lever J is near the face of a toothed wheel O, which is in gear with
another toothed wheel p that is mounted upon the winding shaft L of
the drum D or clockwork. Every revolution of the shaft L causes the
single tooth of the wheel p to partially turn the wheel O, and while the
clockwork is operating the signal such rotation will cause a projecting 2
pin of the wheel O to be carried further and further away from the
inner end of the lever J.
Whenever it is desired to open the guard I it is necessary so to turn
the wheel O as to bring its pin » under the inner end of the lever J,
thereby to raise the inner end of said lever, and carry its outer end out a
of the hook n. To effect this it is necessary to apply the winding key M
to the shaft L through a keyhole provided for that purpose. When the
shaft L has been by means of said key turned so far as to completely
wind up the rope E the pin r will arrive under the inner end of the
lever J, and so swing it as to open the guard. In this manner therefore
the desired object of making the removal and insertion of a lamp
impossible without first winding up the signal operating clockwork is

page_text: completely effccted. Other means for reaching the said object may
however be used. Thus the hinge of the swinging guard I may be so
constructed that by opening the guard the clockwork will be wound up,
or the key M may be so constructed that in a certain position it will
open the guard without requiring the use of the wheel O and the pin r.
In fact I do not confine myself to any special mechanism for carrying
that feature of the Invention, which relates to the combination of the
lock guard I with the clockwork D or key M, into effect.
A modification of the mechanism above described is illustrated in
Figures 4, 5, 6, 7, and 8 of the Drawing, and contains several features of
improvement, more particularly a means for causing the signal to show
the red or danger side to a train whenever any part of the signal-
operating mechanism is out of order. With special reference to these
Figures the letter A represents the stationary frame on which the
signal B is supported, and also all the mechanism for operating said
signal. The signal B is mounted upon a vertical shaft C², which has
its bearings in the frame A², and which by means of bevelled gear
wheels a, or otherwise, is in connection with a drum D², upon which a
weighted cord or rope E² is wound, so that such cord or an equivalent
spring will have the tendency when wound up to rotate the signal on
and with its vertical shaft. This rotation is prevented from being con-
tinuous by one of four, more or less, radially projecting arms be of the
shaft C striking a lug & that projects from the end of an armature
lever F. The armature of said lever is by a spring e² held away from
its electro-magnet G in such way as to bring the lug & in the way of
the arms of the shaft C³, substantially as indicated in Figure 6.
The shaft C when under the influence of the weighted cord rotates in
the direction of the arrow 1, shown in Figure 6. To the armature lever
is also pivoted a trigger f, which yields to the arm bª on its way to the
lug d, but which when the arm strikes said lug swings on its pivot to
elevate the end nearest such arm 6, which prevents the arm b² from
being turned backwards. Thus the trigger constitutes a very reliable
pawl or detent to prevent all backward motion of the shaft C and of the
signal.
As thus far described the apparatus is substantially the same as that
illustrated in Figures 1 and 2, excepting the addition of the trigger f³,
which is an important additional feature. ²² are two arms that

page_text: project from the shaft C³, standing by preference diametrically opposite
each other, as indicated in Figure 6. These arms come in contact
alternately with metal springs i, j, that are mounted upon the frame A²,
and connected by wires l³, m², respectively with the circuit closing
instruments from which the signal is to be affected. The shaft C³
carrying the arms g³, h³, is in metallic connection by wire n², or otherwise
with the electro-magnet G², which in turn communicates by wire o³ with
the ground. Or if but one battery is to be used for the two circuit
closers, by which the instrument is to be operated, such battery may
connect by the wire o² with the electro-magnet, in which case the
wire 1, m², will lead from the springs, j, to the respective circuit
closers, and thence to the ground.
As far as now described the instrument will operate whenever that
one of the circuit closers which connects metallically with the shaft C³
is closed, while any action upon that circuit closer which is not metalli-
cally connected with the shaft C₁ for the time being will not affect the
position of the signal. If for example the circuit closer which connects
with the spring & should be in any way affected by a train or otherwise,
while such spring is not in contact with one of the metal arms on the
shaft C, the signal will of course remain unaffected by such action, but
if the other circuit closer which connects with the spring is properly
affected by a train passing over it while such spring, as in Figure 6, is
in contact with the arm ² a current will be created through the electro-
magnet, and the armature thereby attracted, and the lug & thereby
carried out of the way of the arm b² that rested against it, and the shaft
thereby liberated, as in Figure 7, to revolve in the direction of the
arrow 1, but immediately upon commencing to rotate the arm ³ leaves
the spring, and the current is therefore interrupted and the magnetism
of the electro-magnet terminated, and the armature lever brought under
the influence of the spring e², which carries the lug d² into the way
again of the next succeeding arm 6 to lock the signal in the new
position. Therefore if the signal first showed white its next position
will show red, and vice versa. The lug & after having left contact with
the spring jarrives in contact with the spring 2, and will therefore
serve as a conductor for the current that is created at the next instru-
ment with which the spring connects so as to aid in moving the signal
again as soon as the instrument connected with the spring
by a train or otherwise in the requisite manner.
is affected

page_text: To the supporting frame are or may also be secured a series of metal
tongues p, q, r², 82, which though insulated from the frame A² are by
proper conductors p*, q*, **, s*, joined to instruments which are also
to be operated by the action of the rotating signal B². A wire t² extends
from a local battery into connection with metallic springs pª, qª, 7ª, 8ª,
that are placed respectively opposite to but not in contact with the
tongues p², q², 1³, 82. The springs p^, qª, are about, beneath, or above the
spring, as shown in Figure 4, and the springs r³, sª, are about, beneath,
or above the spring, as shown in the same Figure.
The shaft c² carries beneath or above the arm ga projecting friction
roller ², and beneath or above the arm ² a projecting friction roller v².
Whenever the arm ³ reaches contact with the spring the roller v² also
comes in contact with the springs 7ª, 8ª, and presses said springs against
the tongues ³, s, thereby closing circuits through said tongues and their
respective conductors, and causing distant signals to be operated or
alarms to be sounded, as may be required, so also when the arm ² comes
in contact with the spring its roller v presses the springs p", q^, against
the tongues p, q, thereby closing the circuit at those places, causing
their instruments to show that the signal is in a certain position, the same
action being also obtained from the friction roller u², which is below or
above the arm g².
In practice it will be preferable to use two such instruments at the
ends of a section of line which is to be controlled or protected by the
same, one instrument at the commencement of the section and the other
at the end of the same, both instruments to be so adjusted with reference
to each other that when the first shows white, that is, shows its section
of the track to be clear, the second will show red, that is, show the
section of track to be blocked, yet the first instrument by electric con-
nection with the second causes the second signal to be set, while as soon
as the train reaches the first and as the train reaches the second instru-
ment it will reset the same at red, and thereby by connection of the two
instruments cause the first to be reset at white. If by any chance the
second instrument should be out of order the first will remain red, to
caution an approaching train, and if from any cause the two circuit
closers of both instruments should be accidentally closed at the same
time there would be danger that the signal of the first instrument would
revolve continuously, continuous circuit being established as one of its
arms reaches first the spring ³, then the spring , the other then

page_text: reaching, and so forth. To prevent this a hook-shaped projection 10² is
attached to the armature lever F³, and a projecting stop a to each of those
two arms b³, by which the instrument is locked in danger. The relative
position of the stop a² and hook w² is such that when the signal revolves
and the armature should remain attracted to the electro-magnet the first
arm b which carries the stop will as it arrives over said armature cause
its stop to strike the point of the hook w³, as in Figure 8, and will
then and thereby arrest the arm 6 and the further rotation of the signal,
locking the latter at the position of danger or red; and if thereupon the
armature is withdrawn from the clectro-magnet the hook w² will clear
the stop a and the arm & will be carried against the stop or lug d², tho
same as it would originally have been brought against such stop had
the armature been properly withdrawn originally from the electro-
magnet.
Instead of the special mechanism which has been described with
reference to Figures 1, 2, and 3 for locking the lamp guard so that the
said guard will not be opened without first operating the signal
operating clockwork, a still simpler mechanism is here shown in form of
a slide H, which has a slotted arm y³, through which the weighted
cord E2 passes. A knot Z is formed on said cord E2 below the arm y°.
In winding up the drum D the knot Z³ is finally brought against the
army and raises the same, and with it the slide H³, said slide being by
suitable means connected with a lever that locks the lamp guard,
unlocking it when the slide is raised as aforesaid.
The whole instrument as represented in the Drawing, excepting the
signal, is enclosed in a case, which is held locked by the lever locking the
lamp guard thereto, and the case can therefore not be opened nor the
lamp guard removed unless the rope is first completely wound up to
bring its knot against the slide H, thus insuring the daily winding up of
the clockwork and avoiding danger from neglect.
In Figures 9, 10, 11, and 12 is represented the station master's index
by which he is apprised of the position of the signals above described or
of any other index that may be placed near a track for the purpose above
specified. In these last-mentioned Figures the letter A³ represents a
stationary wall or frame on which the improved instrument is supported.
To this frame or wall is firmly secured a plate B³, to which an electro-
magnet C³ is secured. D³ is the armature of the electro-magnet, its lever

page_text: being pivoted by projecting pins a³, a³, or otherwise in posts b³, 6s,
that
project from the plate B³ or frame A³. The armature lever D³ has a
projecting horizontal arm d³, as shown.
E³ is a metallic rod pivoted at or near its lower ends by a horizontal
pivot in cars f³, f", that project from the plate B³ or frame A³. It is
preferable to hang the rod Es by metallic connection in the projections
of the metallic plate B³, with which one end of the wire of the electro-
magnet C communicates, or else the rod Es by a wire connected with
the plate B3 or with the wire of the electro-magnet.
The upper end of the rod E³ is weighted, as is clearly shown in
Figures 9 and 11, so that when it is brought out of a vertical position it
will fall against one of two gongs F³, G³, or other sounders or audible
devices, that are respectively secured at opposite sides of the rod Es to the
frame A'. The rod E³ is what has been termed the index clapper, as its
weighted upper end constitutes the clapper of the gongs F³, G³, while
it also serves as a visible index to show which position it has last
assumed.
h³ and are two metallic wings or projections on the index clapper j³,
and are two metallic springs or rods so secured to the stationary part
of the apparatus that the clapper will with its wings or pins ³, ¿³, come
in contact with one of said springs when it is swung to one side, and
with the other when swung to the other side. Thus in Figure 9 the pin
or projection is represented as being in contact with the spring, the
clapper being in contact with or near the gong F³. When ⁄³ and j³ are
in contact and ³ are apart, and vice versa invariably.
Now before procceding further it should be understood that by the
term "metal" or "metallic" in this Specification any substance is
meant which is a good conductor of electricity, and that any other
material having the like property will answer the same purpose.
Instead of using the springs ³, 1, and wings or pins h³, 3, the required
metallic contact may be obtained by bodily contact of the index clapper
with the gongs, or by other equivalent means, yet the system of springs
and pins herein described is preferred because it secures more reliable
action.
H³ is a lever pivoted at or near its upper end to the index clapper E³,
as shown in the Drawing, its lower end being suspended over the free
end of the arm d³ of the armature lever.

page_text: The use and operation of the apparatus as thus far described is as
follows: In the station house of the superintendent of a depot, or of any
other proper officer, are secured as many instruments of the kind
described as there are tracks to be watched or controlled. Each
track is supposed to have a circuit closer at each terminus of the
portion to be watched, the wire 13 leading from one of these circuit
closers to the spring, and the wire m³ from the other circuit closer to
the spring. The wire n³ leads from the electro-magnet C³ to the ground,
or if there is to be but one battery it may connect with the electro-
magnet C³, while the wires P, m³, lead to the respective circuit closers,
both of which connect with the ground. Now as long as the portion
of the track to be watched is clear, that is, as long as the same is free
for a train to enter, and while the white signal is displayed, if automatic
signals are used, the clapper rests on or is near one of the gongs, say the
gong G³, which may be marked "clear," as shown, while the other gong
may be marked "blocked," or marks or words of like import may be
used for greater case of ascertaining the true condition of the track.
Pointing thus to "clear" the index clapper causes the electro-magnet to
be in metallic connection through the pin with the spring ³, and wire
m³, the wire m³ leading to that end of the portion of track in question
where an approaching train must enter such portion.
If a train approaches and enters upon the portion of track under
control, the circuit closer is closed at the end of the said portion of the
track by suitable means, either by the weight of the train or otherwise,
and a current immediately created through the wire m³, spring k³, pin ³,
electro-magnet 03, and wire n, thereby the electro-magnet is caused to
attract its armature, and to vibrate the lever or arm d³ and swing it
upwards. The lever H³ while the index clapper is near the gong G³ is
suspended in a vertical position at one side of the pivot e³ of the clapper,
and its lower end is by the motion of the arm d³ struck by said arm which
tends to raise it; but since the lever H³ is pivoted to the index clapper
the upward motion imparted to it by the arm d³ is transmitted to the
pivot of said lever H³ on the clapper, and said pivot consequently raised
i.e., swung with the body of the clapper vertically or nearly so over the
pivot of the clapper. Its inertia carries the weighted clapper beyond
the vertical line and causes it to strike the gong F³. The index clapper
thus attracts the attention of the station master or superintendent by
the sound of the gong F³ to the fact that the track is blocked, and points

page_text: also to such gong (which may be marked as already described), while
the track remains blocked.
By the motion of the index clapper last described the connection
between and is interrupted, but connection between the pin h³ and
spring established and the lever H³ carried to that side of the pivot e³
at which the spring j is located. The position of parts is now as
indicated in Figure 9.
When the train leaves the portion of the track which is under control,
it closes the circuit on the wire 13 and causes a current to pass through
the electro-magnet c³, whereby the armature will be again attracted and
the lever or arm d³ vibrated, as above described; but the effect of the
vibration of the arm d³ will now be to throw the index clapper over to
the other side against the gong G³, and to re-establish connection between
the parts and A³ separating that between the parts h³ and j³. Thus the
instrument always shows whether a given portion of railroad track is
clear or occupied, and sounds moreover an alarm whenever occupation
of such portion of the track commences and when it ceases.
When there are many of these instruments in close proximity an
annunciator I may be suspended in the way of the vibrating index-
clapper, said annunciator being by preference in form of a light
pendulum that will oscillate for a while after the index clapper has
struck a gong. The oscillating annunciator will then show which of a
series of instruments did operate.
If it is desired to utilize the index clapper for transmitting the signals
received to other stations or apparatus of suitable kind, it is only
necessary to attach a metallic plate J³ to said index clapper, but insulate
it therefrom by a plate o³ or otherwise, so that it will not interfere with
any of the currents which have already been described. This plate J³
may by a wire p³ be connected with a local battery and close circuit with
as many prongs or spring conductors 1³, 8³, 1³, and u³, v³, w³, as there are
signals to be transmitted, said spring conductors or prongs being
attached to the frame A³ or plate B³, but insulated from the latter, as
shown in positions, that will enable the plate to connect with the springs
us, v³, and w³, whenever the clapper strikes the gong G³, and with the
springs 3, 3, 3, whenever the clapper strikes the gong F³. The circuits.
thus closed may operate suitable signals at other stations or places, the

page_text: springs, s³, t³, u³, v³, w³, &c., connect of course with suitable con-
ductors, as indicated by dotted lines in Figure 9.
Having described the nature of the Invention and the manner of
performing the same, I declare that what I claim as new and desire to
secure by Letters Patent is,-—
1st. The signal stem C provided with arms or projections 6 which lock
it against the armature F, both in its displayed and concealed positions,
as specified.
2nd. The cams or projections ƒ and g on the stem C, arranged in
combination with the springs i and for operation, in the manner set 1
forth.
3rd. The signal connected metallically with one electro-magnet, and
alternately with one of two operating instruments, as specified.
4th. A lamp guard I locked to a signal apparatus so that the said.
guard cannot be opened without the previous winding of the signal 15
operating clockwork, substantially as herein described.
5th. The combination of the rotary pin r with the lever J, hook n,
and guard I, as set forth.
6th. The trigger f' pivoted to the armature lever F and combined
with the lug d² that projects from said armature lever, substantially as 20
and for the purpose shown and described.
7th. The projecting hook w² attached to the armature lever Fin
combination with the projecting stop x² on the arm 6 of the signal,
substantially as and for the purpose specified.
8th. The friction rollers u³, v², combined with the projecting arms 25
g, h, of the signal shaft, and with the springs pª, qª, 1ª, 8ª, &c., sub-
stantially as and for the purpose described.
9th. The slide H carrying the slotted arm y² and combined with the
rope E, which has the knot Z for the purpose of raising said slide, as
specified.
10th. The combined index and clapper E³ arranged between two
gongs or sounders F³ and G³, substantially as and for the purpose herein
shown and described.
30

page_text: 11th. The lever H³ pivoted to the index clapper E³ and combined with
the armature lever to transmit the motion of the armature to the index
clapper, substantially as herein shown and described.
12th. The pins or projections h³ and is applied to the vibrating index
clapper E, and combined with the springs j³ and ³, substantially as
herein shown and described.
13th. The annunciator I³ combined with the vibrating index clapper
E³, and with the gongs or sounders F³, G³, substantially as herein shown
and described.
14th. In combination with the vibrating index clapper E³, the
insulated plate J³, and conductor prongs or springs ³, s³, ³, v³, &c.,
substantially as herein shown and described.
In witness whereof, I the said William Clark, have hereunto set
my hand and seal, this Fourth day of August, in the year of
our Lord One thousand eight hundred and seventy-five.
THE