IMPROVEMENTS IN ELECTRIC DANGER ALARMS OR SIGNALS,, AND OTHER SAFETY APPLIANCES FOR RAILWAYS
Year: 1881

page_text: LETTERS PATENT to Theodore Al Burtis Putnam, of the City of New York, in
the State of New York and United States of America, Electrician, for an
Invention of "IMPROVEMENTS IN ELECTRIC DANGER ALARMS OR SIGNALS,
PROVISIONAL SPECIFICATION left by the said Theodore Al Burtis Putnam
at the Office of the Commissioners of Patents on the 21st June 1881.
THEODORE AL BURTIS PUTNAM, of the City of New York, in the State of New
York and United States of America, Electrician. "IMPROVEMENTS IN ELECTRIC
DANGER ALARMS OR SIGNALS, AND OTHER SAFETY APPLIANCES FOR RAILWAYS."
The object of my Invention is to warn the engineer or engine driver of a train
when there is danger ahead. I provide for this purpose an automatic electric alarm
on the locomotive which shall operate whenever the train is following too closely
after its leader, whenever it is approaching an open draw or misplaced switch or
other source of danger, whenever it is approaching another train on a single track,
or whenever there is a defect in any of the electric circuits employed.
I arrange on the locomotive or engine a partial electric circuit, including a
generator of electricity and the electro magnet which controls an alarm, and
terminating in two conductors which are arranged in electrical contact with the
track rail. The generator may be a battery or a magneto-electric machine run by
suitable power. The alarm may be an oral alarm, as a gong or whistle, or it may
be a visual signal, and it is normally restrained by operating by the armature of
said magnet, which. is normally attracted to the magnet, but which when the
magnet ceases to attract it is drawn back by a spring, and so renders the alarm
apparatus froe to act.
This partial locomotivo circuit is normally completed through the rail, the rail
conductors being respectively one of the wheels of the locomotive, and a brush or
other conductor. One of these conductors is placed in advance of the other. At
every point or location on the line where it is desired that a sigual be given to the

page_text: engineer in case of danger, two adjoining rails are insulated from each other and
connected by a partial circuit, which includes a circuit breaking or closing-device.
When this partial circuit is broken at this device and the locomotive reaches the
signaling-point with one of its rail conductors on each side of the insulation, the
circuit on the locomotive is broken, the alarm apparatus is released, and the
engineer is warned of danger. But if the partial track circuit is closed at
the circuit breaking device, then when the locomotive rail conductors reach
opposite sides of the insulation, the partial circuit on the locomotive and the
partial circuit on the track will be merged together, and the current from the
generator will flow through both without interruption, so that the alarm will not
bo released.
I also provide means for operating the said circuit breaking device to break the
partial track circuit in case of danger ahead, as will be presently described.
For block signals to prevent one train from following too closely after another,
I insulate one rail from both adjoining rails at each signaling point between the
sections. I will refer to these insulated rails as the first, second, and third, the
intermediate rail being the second. The partial track circuit abovo described
connects the first and second rails, and is broken or closed by a double acting relay,
consisting of two alternately-acting_electro-magnets arranged to act oppositely on
the contact lever. These magnets I will call the "danger" and the "safety
magnets. The danger magnet when excited draws the contact lever away from
the contact stop and breaks the circuit, so that a danger alarm will be given to a
passing train. The safety magnet draws the contact lever against the stop and
closes the circuit. The second and third rails are connected by a partial circuit,
which includes the danger magnet of the relay at their own signaling point and
the safety magnet at a signaling point in the rear. Thus the locomotive when its
conductors connect with the first and second rails will receive an alarm if the first
partial track-circuit be broken, and immediately afterwards when its conductors
connect with the second and third rails its partial circuit is merged with the
second partial track circuit, and a current flows through the latter, thereby setting
the adjacent relay to danger and the one in the rear to safety. If the next
following locomotive reaches the first and second rails at the signaling point in the
rear before this leading locomotive has passed the second and third rails at the
signaling point just described, and consequently before it has telegraphed back and
set the relay in the rear to safety, the following locomotive will receive the danger
alarm.
On single tracks I provide for telegraphing ahead to warn trains approaching
each other from opposite directions of their danger. Each locomotive has its rail
conductors arranged to connect with (for instance) only the right hand rail of the
truck, the other rail being used by locomotives running in the opposito direction.
Both the rails have insulations at each signaling point. The partial circuit between
the first and second insulated rails is before described. That between the second
and third rails includes the safety magnet of the adjacent relay for the opposite
rail of the track, and extends thence ahead to the danger magnet of a remote relay
for said rail. Thus the locomotive sots the relays ahead to danger, and as it
passes them it sets them to safety.
The relay hereinbefore referred to consists by preference of two electro magnets
facing each other, with an armature placed between them mounted on the contact
lever with a light spring to draw it towards the contact stop and the safoty
magnet. This lover carries a projection, which when the lever is attracted toward
the danger magnet is grasped by one or more stationary leaf springs with
sufficient force to hold it against the pull of the first named spring, but not with
suflicient force to prevent its withdrawal when the attraction of the safety maguet
is added to that pull.
I provide means for giving the aların on a locomotive in case it is approaching a
misplaced switch, and also for displaying a signal at the switch in case it is not
isplaced, notifying the switch man that a traiu is approaching. On the track

page_text: remoto from the switch two rails are insulated from each other and connected by a
partial circuit which extends to the switch and includes a circuit breaking device
which is operated mechanically by the shifting of the switch, and also a danger
electro-magnet. If the switch is misplaced this circuit is broken, and an
approaching locomotive receives the alarm, but if the switch is correctly set the
current from the locomotive excites said danger magnet, whereupon the motion of
its armature releases a signal plate or semaphore which flies up in the way of the
switch shifting lever, so that should the switch man attempt to shift the switch ho
will encounter this plate, and must see it. When the locomotive reaches the
switch it passes over two other insulated rails whose connecting partial circuit
includes a safety magnet, which when charged draws down the signal to safety.
For drawbridges I provide a similar arrangement. The circuit from the two
remote insulated rails is broken at the draw, except when the latter is closed and
bolted. A contact lover is forced against a stop to close the circuit by the thrusting
of the bolt. At the draw are the danger and safety magnets in circuit respectively
with the remote and adjacent insulated rails. When the draw is open, or even
unbolted, an approaching locomotive will receive the alarm. When closed and
bolted the current from the locomotive excites the danger magnet and releases a
semaphore, which flies into sight and stands in the way of the bolt handle. As the
locomotive reaches the draw the safety magnet is excited, thereby drawing back
the semaphore.
The
The alarm apparatus on the locomotive is constructed preferably as follows :—
The armaturo of its controlling electro magnet is mounted on a lever which carries
the hammer of a gong. A spring tends to pull the armature away from the
magnet and the hammer toward the gong. When the circuit is broken the magnet
releases the armature, and the spring causes the hammer to strike the gong.
armature lever is then caught by a reciprocating rod or lover, which receives
motion from some moving part of the locomotive, as the valve rod, and the hammer
is thereby drawn back from the gong, whereupon the armature lever slips past
this reciprocating rod or lever, and the hammer flies forward and strikes the gong
again. On the return stroke of the reciprocating rod or lever it moves past a
spring pawl or click on the armature lever. Thus the gong is struck once for cach
revolution of the locomotive driving wheels. The gong will continue to ring until
the engineer moves the armature lever back against the electro magnet, where it
will be held if the current be flowing, but if the circuit be still broken, as by any
defect or imperfect connection, the armature will not be held and the gong will
resume its ringing.
I also provide means for registering the number and time of the alarms given to
the engineer. A strip of paper marked with the hours is drawn slowly between
rollers which are revolved by clockwork. This strip moves past a marking point
or pencil mounted on a lever. When the armature is attracted to the magnet this
point is drawn back from the strip, but when the armature is released the point
springs against the paper and marks it.
My Invention may be applied to other uses on railways in addition to those
herein before stated, as, for instance, for dropping gates across cross roads in advance
of a train, and for signalling the approach of a train at a station or depot.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Theodore Al Burtis Putnam in the Great Seal Patent Office on the
20th December 1881.
THEODORE AL BURTIS PUTNAM, of the City of New York, in the State of New
York, one of the United States of America, Electrician. "IMPROVEMENTS IN
ELECTRIC DANGER ALARMS AND SIGNALS, AND OTHER SAFETY APPLIANCES FOR
RAILWAYS."
The object of my Invention is to warn the engineer or ongino driver of a train
when there is danger ahead. I provide for this purpose an automatic electric alarm
on the locomotive which shall operate whenever the train is following too closely
after its leader, whenever it is approaching an open draw or misplaced switch or
other source of danger, whenever it is approaching another train on a single track,
or whenever there is a defect in any of the electric circuits employed.
In the accompanying Drawings Figure 1 is a side elevation showing a portion
of the track with two locomotives passing in the same direction, the electrical
devices being shown in diagram; Figure 2 is a plan of a single track railway with
electrical devices shown in diagram; Figure 3 is a side elevation of the alarm on
the locomotive on a large scale; Figure 4 is a fragmentary view showing a
modification thereof; Figure 5 is a fragmentary side elevation of the front of the
locomotive on a large scale; Figure 6 is a side elevation of the locomotivo on a
reduced scale showing a modification; Figure 7 is a side clevation of one of the
danger signal transmitters or relays along tho track; Figure 8 is a plan of a switch
showing the electrical appliances in diagram; Figure 9 is a vertical mid section
of a switch shifting mechanism provided with my electric safety appliances; and
Figuro 10 is a diagram showing in plan the track and electrical appliances
connected with a draw bridge.
In all the Figures like letters and numbers of reference designate like parts.
Referring first to Figure 1 let T designate the railway track, which I will
assume to be one track of a double track road, on which trains run in the direction
of arrow 1; L, L, are locomotives or engines thereon; G is an electric current
generator on cach locomotive, which may be, as shown, a magneto-electric machine
run by a donkey engine or other power, or it may be a battery; A is an alarm
apparatus in the cab of the locomotive, which is adapted to give a visual or audible
signal of danger to the engineer, and which tends constantly to give such signal,
but is normally restrained therefrom by the armature of an electro magnet C which
is normally attracted by said magnet; B is a metallic or conducting brush carried
by the locomotive and arranged to sweep the rail in advance of the forward wheel,
or following the rear wheel as preferred. This brush serves to form an electric
connection with the rail, and is insulated from the locomotive. It is best hung as
shown in Figure 5, it being fixed on a lever E and pressed against the rail by a
spring E. A wheel pressed into constant contact with the rail may be substituted
for the brush, as shown in Figure 6. A still better plan in some cases is to make
the rear wheel on the locomotive the forward rail-connection, and the forward
wheels of the tender or of the front car the rear connection, the said wheels being
insulated from the locomotive. I will however assume that a brush is used at the
front of the locomotive. A wire 2 (Figure 1) connects the brush B with the
magnet C, another wire 3 connects said magnet with the generator G, and another
wire or other conductor 4 connects said generator with the wheel R of the
locomotive. In ordinary running (as shown at the left hand or following locomotive
in Figure 1) a closed electric circuit is maintained on the locomotive, the current
flowing from C through 3, C, 2, B, the rail R, and 4, back to the generator (or in

page_text: the contrary direction). Only one of the rails may be used as a part of this circuit.
So long as this closed circuit is maintained the alarm A is restrained from denoting
danger, but whenever the circuit is broken or the current ceases flowing the
alarm is no longer restrained, and it at once acts and the engineer is warned of
danger.
Figure 1 shows the track provided with means for "block signalling" in order
that a train may receive warning in case it is following too closely after a preceding
train. The track is divided into sections or blocks, the dividing points of which I
have marked "point A," "point B," clc. At each of these points I place an
insulated section of rail I between the ends of adjacent rails H and J of the
track T. From the rail H a wire 5 extends to a contact point or screw a, and
from the rail I a wire 6 leads to a contact lever or key b. When b is in contact
with a the circuit I, 6, b, a, 5, H, is completed with the exception of the
break between rails H and I, and when the locomotive reaches the right hand
position in Figure 1 with its brush B on the soil I and its wheel R on the rail H,
the current from generator G passes through 3, C, 2, B, I, 6, b, a, 5, H, R, and 4,
and the circuit is not brokon, but if b is away from a then such circuit is broken
at a, b, and when the locomotive reaches said position (which I call the "signal
receiving position") with its conductors R, B, straddling or bridging the break
between H and I and then the circuit is broken, the magnet C releases the alarm A
and the danger alarm is given to the engineer.
if
The lever b is acted upon by two electro magnets D and S, which constitute a
signaling apparatus or relay K; D is the danger magnet," being the one which
sets the apparatus to danger, that is, when it is charged it draws the lever b out of
contact with the point a, so that the danger alarm will be given to the engineer.
S is the "safety magnet," which when excited draws the lover b into contact with
the point a, so that a passing locomotive shall receive no signal. A wiro 7 leads
from rail I to magnet D, a wire s leads thence back to the magnet S at the
preceding point and another wire 9 leads thence forward again to the rail J at the
starting point, as clearly shown. An earth circuit may be substituted for either
8 or 9.
"
When the locomotive has advanced shortly beyond the signal receiving
position" it reaches the "signal transmitting position," shown in dotted lines in
Figure 1, wherein the conductors B, R, bridge the break between rails J and I. In
this position the current flows through 3, C, 2, B, J, 9 (back to preceding point) S, 8,
(forward again), D, 7, I, R, and 4. In so doing it excites magnet D at (for instance)
point C, thereby setting the relay K there to "danger," and it also excites
magnet S at the preceding point (for instance, "point B"), thereby setting the
relay K there to "safety." Thus the locomotive in its passage first assumes &
position to receive a danger signal if there be one to receive, and it then assumes a
position to set the relay K, which it has just passed, to "danger," and the one at
the preceding point to safety.
Instead of setting the circuit breaking device a, b, to danger by the oxciting of
the magnet D it may be done mechanically by similar means to those shown in
the English Patont of John Clayton Mewburn, No. 1125, dated March 16th,
1$80.
If the following locomotive reaches the receiving position at the preceding point
before the advance locomotive reaches the transmitting position at the next
succeeding point it receives the danger alarm, otherwise it receives no alarm.
In practice I alternate the signal points, that is to say, I place a point C¹ between
points C and D and a point B' between points C and B, and establish the electrical
connection between points B' and C³ that I havo already described between
points B and C.. I have omitted this arrangement from Figure 1 to avoid
complicating the diagrams there and because it forms no novel part of my
Invention.
Figure 2 shows the arrangement employed on a single track to warn trains
when they are approaching each other and prevent collisions. In this case the

page_text: same relay K is used at the signal points and the same arrangement of rails H, I, J,
is employed, except that both are duplicated, each of the two track rails (the upper
and lower rails in Figure 2) being thus provided. The locomotive conductors B, R,
are arranged to connect with only the right hand rail in whichever direction the
locomotive is moving, as shown by arrows 10 and 11. The circuit connections are
somewhat different, owing to the necessity for telegraphing to the signal point
ahead to set the relay K for the opposite rail to "danger," and then when that
signal point is reached to set said relay to "safety."
I will assume that a train is travelling in the direction of arrow 10 in Figure 2.
When its conductors R, B, bridge lower rails H, I, at "point B" it is in position to
receive the danger alarm, which it will receive if another train is approaching it
and has passed "point C," but not otherwise. I will assume that no alarm is
received. When conductors R, B, bridge lower rails I, J, and "point B" tho
current flows from locomotive through brush B, lower rail J, wire 9, to magnet S
at the relay K for the upper (opposite) rail at "point B," thereby setting that relay
to" safety," thenco through wire 8 to magnet D at the relay for said upper rail at
"point C" ahead, thereby setting that relay to "danger," thence through wire 7,
upper rail I (at "point C₁"), wire 12 (which may be an earth circuit), lower rail I
at (point B), and back to locomotive through wheel R. If now a train approaches
point O" in the direction of arrow 11 it will receive an alarm and it will set the
lower relay K at "point B" to danger.
"
In practice two intermediate points "B" and "B"1" are interposed between points
B and C, the several points B¹, C', D', etc., being in electrical connection with each
other, and the several points B, C, D, etc. being also electrically connected. I
have indicated the location of theso points in Figure 2, but for the sake of clearness
I have omitted their electrical provisions which are the same as those shown.
Two locomotives approaching each other will thus both receive the aların when
they are at least as far apart as the length of two blocks or sections, so that each
will have one section to stop in. In practice I shall combine the electrical arrange-
ments shown in Figures 1 and 2, so that a train shall telegraph both forward for
the opposite rail and backward for its own; but to avoid complexity in the diagrams
I have omitted from Figure 2 the provisions shown in Figure 1.
Figure 7 shows the preferred construction of the relay K. The magnets D, S,
are set face to face with the lever b bearing the armature e placed between them.
A spring & tends to draw the lever b against contact screw a, but when the lever
is in the position shown the tendency is resisted by the action of leaf springs e, e,
which grasp a projection on the lever b. The spring d is not strong enough to
pull the projection faway from the springs c, c, until tho magnet S is excited, when
their joint pull releases the projection fand draws the lever b against the screw u.
Then the exciting of the magnet D will draw the lever b back to the position shown.
The springs e, e, are adjusted by the screw e'. One spring e will suffice, or three or
more may be used.
Figures 8 and 9 show my electric-safety appliances in connection with a
switch.
P is the ordinary vertical switch shifting shaft having a handle O (Figure 9), a
radial contacting arm b, and a crank P¹, which connects by a rod Q with the switch
rails. One or more contacting springs a, a, are arranged so that the arm b touches
one or another according to how the switch is set. A signal disk V (Figure 9)
mounted on the armature lever S' of a magnet S tends to fly up in the way of the
handle O, as shown in dotted lines. When drawn down by the magnet, as
shown, it is held by a spring catch lever D² which bears the armature of a
magnet D.
In Fig. 8, M, M', is the main track, and N is a branch track. On each track.
M, M, and N some distance from the switch is the signalling point where rails H
and J are insulated from each other. A wire 5 from each rail H leads to the
magnet S, and thence to the projection b. A wire 6 leads from each rail J to the
corresponding spring a, Near the switch is an insulated rail I from which a wire S

page_text: leads to the magnet S, and from that another wire 9 leads back to the adjoining
rail J.
This
With the switch set, as shown in Figure 8, a locomotive approaching the switch
on the track N will receive a danger alarm when its conductors B, K, bridge the
insulation between rails H and J since the partial circuit H, 5, D, 5, b, a, b, J, is
broken at a, b. A locomotive approaching on track M or M will receive no alarm
since the partial circuit from these tracks is not broken, so that the current from
the locomotive flows through H, 5, D, 5, a, b, 6, J, thereby exciting the magnet D
and causing it to withdraw the catch D' and permit the disk V to fly up.
disk now stands in the way of the handle O, so that if the switchman attempts to
shift the switch he encounters this obstacle and knows that a train is approaching.
If he should need to shift the switch he can press down the disk V with his finger.
When the locomotive reaches the rails I, J, a current flows through I, 8, S, 9 and J,
whereby the magnet S is excited which draws down the lever Stand disk V
again.
The
Figure 10 shows the alarm circuit in connection with a draw bridge.
arrangement is such that unless the draw is closed and bolted the alarm will be
given. A lever b is arranged to bo pressed against a contact spring a by contact
of the bolt h when that bolt is thrust home to lock the draw. Lever 6 connects by
wire 6 to rail J, and spring a connects by wire 5 to rail H. The locomotive
receives the alarm when crossing the break or insulation between H and J, as
already described in the other cases.
The wire 5 passes through magnet D, and another magnet S is connected by a
wire 9 with rail J, and by a wire 8 with an insulated rail I; D¹ is the armature
catch lever of magnet D, and S₁ is the armature lever of magnet S bearing signal
plate V on its end. When the locomotive crosses from H to J and receives no
alarm, a current flows through J, G, b, a, 5, D, 5, and H, thereby exciting magnet D,
withdrawing catch D¹ and permitting lever S¹ to spring into the position. shown,
where the plato V stands in the way of the bolt handle O which notifies the bridge
tender that a train is approaching. When the locomotive passes from J to I, a
current flows through magnet S, thereby drawing lever S¹ back and moving plate V
out of the path of handle O.
Figure 3 shows the alarm apparatus on the locomotive. Whenever the mechanism
is released a gong is struck once for each revolution of the driving wheel.
A connecting bar i is linked to the locomotive valve rod so as to reciprocate with
it, and it is coupled to one arm of a lever j, whose other arm connects with a
sliding bar which has a catch or shoulder 7. The armature m of the magnet C
is mounted on a lever n which bears the hammer o and is drawn by the spring p
against a stop q whenever the armature is released by the cessation of the current
through the magnet C. A snap dog or click is jointed to the lever n and kept
pressed up to place by a spring 8. The shoulder in moving from the position shown
in full lines to that shown in dotted lines, 'presses back this dog, which at once
returns to its normal position. Then when the shoulder is making its return
movement (to the right) it catches against the dog and moves the entire lever n
with it, thereby drawing hammer o from gong t. The shoulder & then slips from
under dog r, whereupon spring p draws lever back, causing hammer o to striko
gong t. The alarm when once released will ring until it is set back by the
engineer, which he does by pulling down a rod u until the armaturem is brought up
close to the magnet C again, when it will be attracted and held there if the circuit
be closed again, but if the circuit be still broken it will not be upheld, 'and the
alarm will continue to sound. As the cessation in the locomotive circuit is only
instantaneous while the conductors B, R, are passing over the break between the
rails H, I, or H, J, the engineer, if he cannot set back the alarm, will know that
the circuit on the locomotive is faulty, or that the generator G is not in operation.
Instead of forming the shoulder on the bar, that bar may be omitted, and
the end of the lever j' may serve as the said shoulder, the position of the lever being

page_text: changed, as shown in Figure 4. The lever ; may receive its motion from any other
constantly moving part of the locomotive instead of from the valve rod.
Instead of ringing the bell the release of the armature m may open a valve and
admit steam to the whistle of [the locomotive, so that whistle will constituto
the alarm. Instead of providing a constantly sounding alarm the means for
constantly ringing may be omitted, and some visual danger signal may be employed
to be brought into view when the armature m is released, as indicated by dotted
lines at F in Figure 3. In this case the gong will ring only once as the signal F
comes into view.
A lever vis arranged adjacent to the magnet C and bears a marking point v',
which may be a pencil, or pen, or a mero sharp point, as shown. A spring forces
the point forward except when the armature m is adhering to the magnet, at
which time the end of the armature lever n deflects the lever vand draws back
the point A strip g of paper marked with the hours is passed slowly across
the point v¹, which when drawn back does not quite touch it, but which when
forward, as shown, indents it. The strip g is drawn slowly from a reel g' by the
revolution of rollers or gripping wheels x, x, which receive their motion from a
clock work contained in box y seen behind the other parts. Whenever the alarm
is released and operates the point marks the strips g, which thus records the
time at which the alarm was given. In case of accident this record will show
whether the engineer disregarded a warning of danger or not.
In addition to the applications of my Invention which are shown in the
Drawings, it may also be used for many other purposes connected with the
operation of railways, as, for instance, for dropping gates at cross roads in advance
of a train, and for signalling the approach of a train to a station or depôt.
Having now described and fully ascertained the nature of my said Invention, I
declare that I claim,―
1. A locomotive provided with a partial closed electric circuit including a
generator, and the electro magnet controlling an alarm and terminating in two
conductors arranged in electrical contact with the rail, whereby the circuit is
normally completed between said conductors through the rail, substantially as set
forth.
2. A railway track having two adjoining rails insulated from each other,
electrical conductors adapted to form an electrical connection between them and
means of breaking and closing said connection in combination with a locomotive
carrying an electric generator and an alarm, both included in an incomplete
circuit, which terminates in two conductors arranged one in advance of the other
and both in contact with the rail, substantially as set forth.
3. A railway track having at each signaling point three successive rails insulated
from each other, a partial circuit connecting the first and second rails and including
a circuit breaking device operated by two oppositely acting and alternately acting
electro magnets, and a partial circuit connecting the second and third rails and
including one of said magnets at its own signaling point, and the other of said
magnets at a remote signaling point.
4. The relay for signaling points constructed to open or close a signal circuit by
the action of two oppositely arranged electro magnets, and provided with the
devices for retaining the circuit open or closed, substantially as described and
shown.
5. A railway switch provided with a circuit breaking apparatus operated by the
shifting of the switch and included in a partial circuit which terminates in two
successive insulated rails at a remote point on the track, arranged and adapted to
operate substantially as shown and described.
G. A railway draw-bridge provided with a circuit breaking apparatus operated
by the bolting of the draw to close a partial circuit which extends to a remote
signalling point and there terminate in two successive insulated rails, all arranged
and adapted to operate substantially as herein before set forth.

page_text: 7. A railway switch or draw-bridge provided with a partial circuit extending to
a remote point on the track and there terminating in two insulated rails, and
including at the switch or draw an electro magnet, which when excited causes a
signal to appear in combination with another magnet, which when excited causes
said signal to return included in another partial circuit which terminates in two
adjacent insulated rails, all constructed and arranged to operate substantially as
set forth.
8. The alarm apparatus on the locomotive whereby a gong is struck at each
revolution of the driving wheels whenever the controlling electro magnet loses its
magnetism by the breaking of the circuit, constructed and arranged substantially
as shown in Figure 3 and as set forth.
9. The recording device for registering the time at which an alarm has been
given to the engineer, constructed and arranged to operate substantially as shown
in Figure 3 and as described.
In witness whereof, I, tho said Theodore Al Burtis Putnam, have hereunto set
my hand and scal, this 29th day of November, in the year of our Lord
1881.
THEODORE AL BURTIS PUTNAM. (L.S.)