Improved Means for Electrically Signalling and Operating Crossing Gates on Railways.
Year: 1889

page_text: Date of Application 1st Mar, 1889
Complete Specification Left, 19th. Mar., 1889
Complete Specification Accepted, 1st June, 1889
PROVISIONAL SPECIFICATION.
Improved Means for Electrically Signalling and Operating Crossing
Gates on Railways.
1, THEODORE AL BURTIS PUTNAM, of No. 57 Lexington Avenue, in the City of
New York, United States of America, Electrician, do hereby declare the nature of
this invention to be as follows:-
This invention relates chiefly to electric railway signals of that class wherein an
alarm is given in case of danger by mechanism carried by the locomotive engine, and
arranged preferably in the cab. Signals of this character have the advantage over
semaphores or visual signals located on the track that the danger signal is forced
upon the attention of the engine driver and is not liable to be overlooked by him in
consequence of darkness, fog or storm.
The invention relates particularly to signaling systems in which the rails of the
railway-track are used as a part of the electric circuit, and the electric current is
supplied by a dynamo electric machine or a galvanic battery carried by the locomotive
engine. Signal-receiving and transmitting points are provided at intervals along the
line, and from each signal transmitting point electric circuit wires are extended along
the railway track to one or more signal-receiving points, where electro-magnets or
other devices are provided for receiving the signals.
This invention introduces the use of induction coils at the signal-transmitting
points arranged to receive a momentary electric current through the primary wire
and the secondary wire of each coil being connected with an electric circuit extending
thence to the remote signal receiving point.
Fig. 1 of the accompanying drawings is an elevation of a portion of a locomotive
engine and its tender showing the preferred arrangement of electrical apparatus and
circuits carried by the locomotive.
The locomotive engine carries a dynamo G (or a galvanic battery or other generator
of electricity), one terminal of which is connected electrically with one of the
wheels B of the locomotive, and the other terminal is connected with one of the
wheels W of the tender, thus constituting a partial circuit c c. The wheels B and W,
which are insulated from each other, thus constitute the terminals of this partial
circuit, the circuit being normally closed and completed through the wheels and the
rail R, as shown by the dotted lines c¹. In this partial circuit c c is included an
electro-magnet A which operates the danger alarm or signal in the cab. The danger

page_text: signal shown consists of a whistle & supplied with steam by a pipe i leading from the
boiler and controlled by a valvej which is normally held closed by the armature k
which is attracted by the magnet A and which is mounted on a lever connected to
the valve. Either a retracting spring m or the steam-pressure on the valve j, or both,
tends to draw the armature away from the magnet A, but so long as the circuit c
remains closed so that an electric current flows through the magnet A the latter
continues to attract its armature and the signal is restrained from sounding.
A relay magnet R is arranged in a shunt-circuit d d of high resistance extending
from one terminal of the dynamo & to the other. For example, if the resistance of
the circuit cc, including the magnet A, is two ohms, the resistance of the shunt-
circuit dd, including the relay R, may be approximately 10 ohms. This resistance is
peferably attained by introducing a rheostat r. Normally the current traversing the
relay R is insufficient to attract its armature-lever e against the tension of its retracting
spring g so that the lever e remains in contact with a stop-screw f and the circuit c²
to the magnet A remains closed.
The
The railway track is provided at intervals with an insulation y between two
successive track rails. When the locomotive engine runs over this insulation so that
for a moment the wheels B W are on opposite sides thereof, the circuit c c cannot be
completed through the rails but will normally be broken by the insulation y.
cessation of current in the magnet A releases its armature k, the valve j is opened and
steam enters the whistle h, whereby the alarm is given to the engine driver. It
y is
sometimes occurs, however, especially in wet weather, that the insulation at
imperfect, so that instead of the circuit being broken there is a leakage around the
insulation, as indicated by the dotted line a, which has the effect of introducing a
resistance into the partial circuit cc which varies according to circumstances. In
practice it will usually exceed 10 ohms. In such case the resistance of the circuit ee
is increased, for example from 2 ohms to 12 ohms while the resistance of the shunt dd
remains at 10 ohms. Hence the current flowing through the shunt increases from
two-twelfths of the total current to six-elevenths thereof. This increase is sufficient, to
attract the armature-levere and break contact with the spring f, whereby the partial
circuit ccc is positively broken and the alarm magnet A is forced to release its
armature and give the alarm. Thus the giving of the alarm is ensured under all
circumstances notwithstanding the existence of defective insulation at y, or leakage
caused by wet weather, etc.
In addition it is preferable to provide on the locomotive an additional shunt-
circuit extending directly from the dynamo to the wheel B, and cutting out the
This shunt c³ includes a rheostat or
relay-lever e, stop, and alarm-magnet A.
resistance considerably in excess of the resistance of the magnet A, say, for
example, about 10 ohms. The purpose of this shunt will be presently described. It
is omitted from Figs. 3 and 4.
In practically applying this system of signaling to a railway the lino is divided into
blocks or sections by means of signal points arranged at any suitable distance apart,
say, for example, every mile. Fig. 5 is a diagram of a portion of a double-track
railway showing four of these signalling points marked respectively L, M, N and O.
At each such point one length of rail is insulated at its opposite ends from the
preceding and following rails. Thus at each signaling point each of the two tracks is
provided with a break or insulation y (Fig. 1) constituting a signal-receiving point
marked Rc and with a signal transmitting point Tr. From each signal point an
electric signaling circuit extends from T back to Rc at the second preceding signal
point, as indicated by the several arrows nn in Fig. 5. For example, the circuit
extends from Tat Point N back to Re at Point L, and from Trat Point O back to
Rc at Point M.
7"
Fig. 2 is a diagram showing the preferred circuit connection between Tr and R c.
An induction coil P is arranged near the track at each signal point and the terminals
of its primary coil are connected by wires pp to the rails R' on opposite sides of an
insulation or break y so that during the instant that a locomotive engine is passing
over this insulation the current from its dynamo G will flow from wheel B through

page_text: wires
P
to the primary of the induction coil and the two rails back to the wheel W.
Thus the insulation y is bridged across by the wires p p and the primary coil so that
the circuit c c on the locomotive engine is not interrupted and no danger alarm is
given. The secondary coil of the induction coil P has its terminals connected by
wires ss leading to a magnet S at a distant signal point. The momentary current
through the primary of the induction coil induces currents in the secondary coil
which traverse the wires s and excite the magnet S, causing it to attract its armature
and give the signal at Rc.
The manner in which this signal is given may be best understood from Figs. 3
and 4. These views are diagrams showing two locomotive engines passing
respectively the signal points L and N in Fig. 5. The locomotive in Fig. 3 is at the
signal receiving position and in Fig. 4 in the signal transmitting position.
In these figures I is the insulated rail, H is the preceding rail and J the following
rail. The primary of the induction coil P is connected by the wires p p to the rails
and J respectively. The rails H and I are connected by a conducting bridge con-
sisting of wires 5 and 6 terminating in a contact-stop a and a contact-lever b, so that
when the lever touches the contact the insulation is bridged across by the
conducting wires 5-6 and no danger signal is given, this being the condition of
"Safety, but when the lever bis out of contact with a the signal receiving point is
Danger," and when next a locomotive passes this point its magnet A will
operate and give the danger signal. The contact-lever is operated by two electro-
magnets D and S, which attract an armature carried by this lever. The magnet D is
connected with the secondary of the induction coil P at the same signaling point,
while the magnet S is connected by the wire s with the secondary of the induction
coil P at the second signaling point in advance.
set to "
A locomotive engine running on the track in the direction of the arrow in Figs: 3
and 4 reaches first the signal receiving point Re, and if the lever b stands at
Danger" the partial circuit c c will be broken and the alarm-magnet A will release
its armature and the relay-magnet R will attract its armature, all as shown in Fig. 3,
thus giving the engineer the danger signal. The engineer will thus know that the
preceding train has not yet passed beyond the second signalling point in advance, and
The next
he will know that he must stop or run ahead slowly and with great care.
instant_the_locomotive reaches the signal transmitting position T and sends its
current through the primary wire of the induction coil P, as shown in Fig. 4. The
current in the secondary coil traverses the magnet D at the same signaling point and
sets the lever to "Danger (if it be not already so set), and also Hows back
through the wires to the safety magnet S at the second point in the rear, so that this
Safety."
magnet S attracts the lever band sets it to "
Thus each locomotive engine
first receives a danger signal if there be one to receive, and then sets the signal it has
just passed over to "Danger" and sets a signalling point at a sufficient distance in
the rear to "Safety."
22
After the danger signal has been given the engineer will pull back the lever / with
his hand, thereby setting the alarm ready for receiving the next signal. Any suitable
means may be provided for setting back the levere of the relay R by the same
manipulation. This means may consist of a switch for short-circuiting the relay R
so that the spring g may pull off its lever e..
While the alarm signal is sounding the circuit c c² is broken, and if at this moment
the locomotive should reach the signal transmitting position T it would send no
current through the induction coil P. To prevent this occurrence the shunt circuit c³
and rheostat is provided. If this rheostat has a resistance of 4 ohms, the magnet A
tohms and the shunt d d 10 ohms, then normally the current will divide in the
proportion of two-twelfths through the relay R, five-twelfths through the alarm-
imagnet A and five-twelfths through the rheostat Q. On reaching the receiving position
the
and receiving the danger signal with a leakage of 10 ohms across the insulation
current will divide in the proportion of twelve-twenty-seconds through the relay R,
five twenty-seconds through the magnet A and five twenty-seconds through the
rheostat Q, thus increasing the current through R more than three times and causing

page_text: it to act and shunt out the magnet A. At the next instant, having passed the
receiving position, the current will flow four-fourteenths, 4, through the relay Rand
ten-fourteenths, 10, through the rheostat Q. If now the transmitting position is
reached and the primary of the induction coil has a resistance of, say, 4 ohms, ten-
eighteenths of the current will still flow through the circuit c c and shunt and
through the primary of the induction coil, which will be sufficient to operate 'the
induction coil and send a signal back through the wire s.
Fig. 6 shows the preferred construction of the receiving instrument for operating
the contact-lever 6. This lever is niounited between two electro-magnets U and S
'carrying the armatures thereof and vibrates between two screw-stops. Its end when
in the position shewn makes a rubbing contact with a leaf-spring which is adjusted
by a screw t and has a stop u to prevent its end descending too low. When' the lever
s in either position it might be liable to be thrown over to the opposite position by
jarring or vibration. To prevent this it is formed with a knife-edge which bears
against a disk w carried by a spring w¹. As the lever moves toward the center it
lifts this disk against the tension of the spring w¹ and in moving beyond the center the
tension of the spring tends to throw it over and hold it there. Instead of the disk w
a toggle-link may be used to the same effect.
To
The induction coil P might be omitted and the wires ss joined directly to the rails R
on opposite sides of the insulation y, but in this case it would be necessary to use
coarse wire of low resistance in order that the resistance of the circuit ss and its
magnet S should be less than the minimum resistance of the leak in Fig. 1, as
otherwise the alarm would be given when crossing the transmitting point Tr.
make the circuit s which extends to a considerable distance (for instance two miles)
of sufficiently coarse wire would be very expensive, and is avoided by the use of the
induction coil P. However, in the application of my system of signals to switches or
shunting points and to draw bridges (in which cases it is desirable to signal the
switchman or the bridge attendant of the approach of a train, as well as to give a
danger signal to the engine driver if the switch is wrongly set or the draw is open) I
omit the induction coil P and construct the circuit ss of coarse wire, and provide at
the switch or draw a circuit-breaker adapted to open the circuit s s in case of danger,
so that if the switch or draw is open the engine driver will receive a danger signal,
while on the contrary, if the switch or draw is properly set the engine driver will
receive no signal, but the attendant at the switch or draw will receive a signal so that
he will know that a train is approaching.
My system of signaling is applicable to the ringing of bells in railway stations, or
at road crossings or in tunnels to announce the approach of a train, also for the
automatic operation of gates or signals at road crossings. It is also applicable to
single-track railways instead of double-track ones, in which case, however, each signal
point L, M, N, etc., should be connected not only to a signal point in the rear, but also
to a signal point in advance in order to warn the drivers of two approaching engines
and prevent their collision.
The danger signal on the locomotive engine may be an electric bell or a visual
"signal instead of the whistle h. Any other means may be provided for attracting the
attention of the engine driver, such as by sending an electric shock through his person.
The rear terminal W of the partial circuit c c might be the wheels of the last
'carriage or car of the train instead of the wheels of the tender.
In this case any
"accidental breaking or uncoupling of the train will break the circuit c c and cause an
alarm to be given to the engine driver.
Dated the 1st day of March. 1889
J.C.
MEWBURN,
55 & 56, Chancery 'Lane, London,
Patent' Agent.

page_text: Improved Means for Electrically Signalling and Operating Crossing
Gates on Railways.
1, THEODORE AL BURTIS PUTNAM, of No. 57 Lexington Avenue, in the City of
New York, United States of America, Electrician, do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-—
This invention relates chiefly to electric railway signals of that class wherein an
alarm is given in case of danger by mechanism carried by the locomotive engine,
and arranged preferably in the cab. Signals of this character have the advantage
over semaphores or visual signals located on the track that the danger signal is forced
upon the attention of the engine driver and is not liable to be overlooked by him in
consequence of darkness, fog or storm.
The invention relates particularly to signalling systems in which the rails of the
railway-track are used as a part of the electric circuit, and the electric current is
supplied by a dynamo electric machine or a galvanic battery carried by the locomo-
tive engine. Signal receiving and transmitting points are provided at intervals
along the line and from each signal transmitting point electric circuit wires are
extended along the railway track to one or more signal receiving points, where
electro-magnets or other devices are provided for receiving the signals.
This invention introduces the use of induction coils at the signal-transmitting
points arranged to receive a momentary electric current through the primary wire,
and the secondary wire of each coil being connected with an electric circuit extending
thence to a remote signal receiving point.
Figure 1 of the accompanying drawings is an elevation of a portion of a locomo
tive engine and its tender showing the preferred arrangement of electrical apparatus
and circuits carried by the locomotive.
The locomotive engine carries a dynamo G (or a galvanic battery or other
generator of electricity) one terminal of which is connected electrically with one of
the wheels B of the locomotive, and the other terminal is connected with one of the
wheels W of the tender, thus constituting a partial circuit c c. The wheels B and W.
which are insulated from each other, thus constitute the terminals of this partial
circuit, the circuit being normally closed and completed through the wheels and the
rail R', as shown by the dotted lines c'. In this partial circuit c c is included an
electro-magnet A which operates the danger alarm or signal in the cab. The danger
signal shown consists of a whistle h supplied with steam by a pipe leading from
the boiler and controlled by a valve j which is normally held closed by the armature k
which is attracted by the magnet. A and which is mounted on a lever / connected to
the valve. Either a retracting spring m or the steam-pressure on the valve j, or
both, tends to draw the armature away from the magnet A, but so long as the
circuit c remains closed so that an electric current flows through the magnet A the
latter continues to attract its armature and the signal is restrained from sounding.
A relay magnet R is arranged in a shunt-circuit d d of high resistance extending
from one terminal of the dynamo G to the other. For example, if the resistance of
the circuit cc, including the magnet A, is two ohms, the resistance of the shunt-
circuit d d, including the relay R, may be approximately 10 ohms. This resistance
is preferably attained by introducing a rheostat r. Normally the current traversing
the relay is insufficient to attract its armature-lever e against the tension of its

page_text: a
retracting spring so that the levere remains in contact with a stop-screw ƒ and
the circuit c to the magnet A remains closed.
According to one construction or system of signals the railway track is provided
When the
at intervals with an insulation y between two successive track rails.
locomotive engine runs over this insulation so that for a moment the wheels B W
are on opposite sides thereof, the circuit c c cannot be completed through the rails
but will normally be broken by the insulation y. The cessation of current in the
magnet A releases its armature k, the valve jis opened and steam enters the whistle h,
whereby the alarm is given to the engine driver. It sometimes occurs, however,
especially in wet weather, that the insulation at y is imperfect, so that instead of
the circuit being broken there is a leakage around the insulation, as indicated by
the dotted line, which has the effect of introducing a resistance into the partial
circuit cc which varies according to circumstances. In practice it will usually
exceed 10 ohms. In such case the resistance of the circuit c¸c is increased, for
example from 2 ohms to 12 ohms while the resistance of the shunt d d remains at
10 ohms. Hence the current flowing through the shunt increases from two-twelfths
of the total current to six-elevenths thereof. This increase is sufficient to attract the
armature-levere and break contact with the spring, whereby the partial circuit ce c²
is positively broken and the alarm magnet A is forced to release its armature k and
give the alarm. Thus the giving of the alarm is ensured under all circumstances
notwithstanding the existence of defective insulation at y, or leakage caused by wet
weather, etc.
In addition it is preferable to provide on the locomotive an additional shunt-
circuit extending directly from the dynamo to the wheel B, and cutting out the
relay-lever e, stopf, and alarm-magnet A. This shunt e³ includes a rheostat or resist-
ance considerably in excess of the resistance of the magnet A, say, for example,
about 10 ohms. The purpose of this shunt will be presently described. It is omitted
from Figs. 3 and 4.
In practically applying this system of signaling to a railway the line is divided
into blocks or sections by means of signal points arranged at any suitable distance
apart, say, for example, every mile. Fig. 5 is a diagram of a portion of a double-
track railway showing four of these signalling points marked respectively L, M, N and O.
At each such point one length of rail is insulated at its opposite ends from the
preceding and following rails. Thus at each signalling point each of the two tracks
is provided with a break or insulation y (Fig. 1) constituting a signal-receiving point
marked Re and with a signal transmitting point Tr. From each signal point an
electric signalling circuit extends from Tr back to Re at the second preceding signal
point, as indicated by the several arrows nn in Fig. 5. For example, the circuit
extends from Tr at Point N hack to Rc at Point L, and from T at Point O back
to Re at Point M.
Fig. 2 is a diagram showing the preferred circuit connection between Trand Rc.
An induction coil P is arranged near the track at each signal point and the terminals
of its primary coil are connected by wires p p to the rails on opposite sides of
an insulation or break y so that during the instant that a locomotive engine is
passing over this insulation the current from its dynamo G will flow from wheel B
through wires to the primary of the induction coil and the two rails back to the
wheel W. Thus the insulation y is bridged across by the wires p p and the primary
coil so that the circuit c c on the locomotive engine is not interrupted and no danger
alarm is given. The secondary coil of the induction coil P has its terminals con-
nected by wires ss leading to a magnet S at a distant signal point. The momentary
current through the primary of the induction coil induces currents in the secondary
coil which traverse the wiress and excite the magnet S, causing it to attract its
armature and give the signal at Rc.
The manner in which this signal is given may be best understood from Figs. 3 and 4.
These views are diagrams showing two locomotive engines passing respectively the
signal points Land N in Fig. 5. The locomotive in Fig. 3 is at the signal receiving
position and in Fig. 4 in. the signal transmitting position.

page_text: 86
.
In these figures I is the insulated rail, H is the preceding rail and J the following
rail. The primary of the induction coil P is connected by the wires p p to the rails
and J respectively. The rails H and I are connected by a conducting bridge
consisting of wires 5 and 6 terminating in a contact-stop a and a contact-lever b, so
that when the lever touches the contact the insulation y is bridged across by the
conducting wires 5-6 and no danger signal is given, this being the condition of
Safety," but when the lever is out of contact with a the signal receiving point is set
to Danger," and when next a locomotive passes this point its magnet A will
operate and give the danger signal. The contact-lever is operated by two electro-
magnets D and S, which attract au armature carried by this lever. The maguet Dis
connected with the secondary of the induction coil Pat the same signalling point,
while the magnet S is connected by the wire s with the secondary of the induction
coil P at the second signalling point in advance.
"
The next
A locomotive engine running on the track in the direction of the arrow in
Figs. 3 and 4 reaches first the signal receiving point Rc, and if the lever 6 stands at
Danger" the partial circuit c c will be broken and the alarm-magnet A will release
its armature and the relay-magnet R will attract its armature, all as shown in Fig. 3,
thus giving the engineer the danger signal. The engineer will thus know that the
preceding train has not yet passed beyond the second signalling point in advance, and
he will know that he must stop or run ahead slowly and with great care.
instant the locomotive reaches the signal transmitting position Tr and sends its
current through the primary wire of the induction coil P, as shown in Fig. 4. The
current in the secondary coil traverses the magnet D at the same signalling point and
sets the lever to "Danger" (if it be not already so set), and also flows back through
the wires to the safety magnet S at the second point in the rear, so that this
magnet S attracts the lever and sets it to Safety." Thus each locomotive engine
first receives a danger signal if there be one to receive, and then sets the signal
it has just passed over to "Danger" and sets a signalling point at a sufficient
distance in the rear to "Safety.'
After the danger signal has been given the engineer will pull back the lever with his
hand, thereby setting the alarm ready for receiving the next signal. Any suitable means
may be provided for setting back the lever-e of the relay-R by the same manipulation.
This means may consist of a Switch for short-circuiting the relay R so that the
spring g may pull off its lever e.
While the alarm signal is sounding the circuit ce² is broken, and if at this moment
the locomotive should reach the signal transmitting position T it would send no
current through the induction coil P. To prevent this occurrence the shunt
circuit 3 and rheostat is provided. If this rheostat has a resistance of 4 ohms,
the magnet A4 ohms and the shunt dd 10 ohins, then normally the current will
divide in the proportion of two-twelfths through the relay R, five-twelfths through the
alarm-magnet A and five-twelfths through the rheostat Q. On reaching the
receiving position and receiving the danger signal with a leakage of 10 ohms across
the insulation y the current will divide in the proportion of twelve-twenty-seconds
through the relay R, five-twenty-seconds through the magnet A and five-twenty-
seconds through the rheostat Q, thus increasing the current through R more
than three times and causing it to act and shunt out the magnet A. At the next
instant, having passed the receiving position, the current will flow four-fourteenths,
through the relay R and ten-fourteenths, 18, through the rheostat Q. If now
the transmitting position is reached and the primary of the induction coil has a
resistance of, say, 4 ohms, ten-eighteenths of the current will still flow through the
circuit cc and shunt and through the primary of the induction coil, which will
be sufficient to operate the induction coil and send a signal back through the wire s.
Fig. 6 shows the preferred construction of the receiving instrument for operating
the contact-lever b. This lever is mounted between two electro-magnets and S
carrying the armatures thereof and vibrates between two screw-stops. Its end when in
the position shown makes a rubbing contact with a leaf-spring a which is adjusted by
When the lever b
a screw and has a stop u to prevent its end descending too low.

page_text: is in either position it might be liable to be thrown over to the opposite position by
jarring or vibration. To prevent this it is formed with a knife-edge which bears.
against a disk w carried by a spring w¹. As the lever moves toward the center
it lifts this disk against the tension of the spring w' and in moving beyond the
center the tension of the spring tends to throw it over and hold it there. Instead of
the disk wa toggle-link may be used to the same effect.
To
The induction coil P might be omitted and the wires ss joined directly to the
rails R on opposite sides of the insulation y, but in this case it would be necessary
to use coarse wire of low resistance in order that the resistance of the circuit s s and
its magnet S should be less than the minimum resistance of the leak a in Fig. 1. as
otherwise the alarm would be given when crossing the transmitting point Tr.
make the circuits which extends to a considerable distance (for instance two miles)
of sufficiently course wire would be very expensive, and is avoided by the use
of the induction coil P. However, in the application of my system of signals
to switches or shunting points and to draw bridges (in which cases it is
desirable to signal the switchman or the bridge attendant of the approach of a train,
as well as to give a danger signal to the engine driver if the switch is wrongly
set or the draw is open) I omit the induction coil P and construct the circuit s s of
coarse wire, and provide at the switch or draw a circuit-breaker adapted to open the
circuit s s in case of danger, so that if the switch or draw is open the engine driver
will receive a danger signal, while on the contrary, if the switch or draw is properly
set the engine driver will receive no signal, but the attendant at the switch or draw
will receive a signal so that he will know that a train is approaching.
The insulation of the rails at the signalling points is sometimes objectionable. In
such cases to avoid insulating the rails I have designed the modification of my system
shown in Fig. 7, which is a diagram similar to Fig. 3. At each signal-receiving and
transmitting position I apply a conducting rail or plate Con or along the track insulated
from the track rails R¹ and preferably arranged between the two rails. The locomotive or
tender carries a lever E the end of which rubs over the contact rails CC in passing.
The rails C C are placed at such height as to lift the lever against the pressure of a
spring m, thereby moving its end n out of contact with a spring or stop o. The
lever-arm n and contact-spring o are included in the circuit e leading from the
generator g to the wheel w (or to the wheel B if preferred). Normally the current
flows from the generator G through the circuit cc, through contacts no to wheel w,
thence through the rail R¹ to wheel B and thence back to the generator. When,
however, the lever E'is passing over one of the contact rails C this circuit is broken
at no and the current may flow through lever E, plates C, wire 5, contacts a b,
wire 6, rail R¹and wheel B back to the generator. If, however, the circuit is broken at a b
no current will pass and the danger alarm will be given. In passing over the rail C
at Tr, the current flows from the lever E to the rail C, thence through wire p to the
primary of the induction coil P by the wire p¹ to the rail R' and thence through
wheel B back to the generator G. Thus a current is sent through the induction coil
and circuit s s back to the preceding signalling points.
•
It will be seen that the insulated contact-rails. CC at the positions Rc and Tr
serve the same purpose as the insulation of the rails H and J from the rail 1 in
Figs. 3 and 4. Thus the expense and difficulty sometimes attending the insulation of
track rails at their joints may be avoided, without impairing the operation of
my system of signalling.
The use of the induction coil P is not as advantageous with this construction as
with that shown in Figs. 1 to 4. When desired the induction coil may be entirely
omitted and the wires p, p' be joined directly to the circuit-wires s s.
Figs. 8 to 11 show the preferred construction for applying this modification of my
system. The lever E carried by the locomotive is hung in a ball and socket joint
consisting of a half ball or sphere a¹ working in a casing . A square plate d'
shown in plan in Fig. 11 fits over the half ball a¹ and is pressed down by four
springs s¹, as shown in Figs. 8 and 9. A contact-arm e¹ projects from the ball a¹ and
when the lever E is in the normal position the upper end of this arm touches a

page_text: contact-spring o which is connected by a wire c* with the wheel W in Fig. 7.
When
the lever E is tilted as shown in Fig. 8, its arm E¹ breaks contact with spring o which
falls upon a stop o¹. The case is connected by wire c, Fig. 8, with the generator G
shown in Fig. 7.
The contact-rails or plates CC on the track consist each of a fixed plate f¹ and a
movable plate, shown in plan in Fig. 10, the latter being mounted on a lever g¹
and pressed against the plate f¹ by a spring h', as shown in the transverse section
Fig. 9.
The fixed plate is rigidly supported on frames in which the lever g' is
pivoted. These frames are bolted to the wooden cross-ties or sleepers, by which
means the complete structure C is insulated from the track-rails.
The lever blade E enters the flared ends 3 of the plates and presses the
plates slightly apart, sliding through between them, whereby it makes a good
electrical contact with them. The friction of the plates against the lever drags the
latter backward thereby deflecting its contact arme and forcing it out of contact
with spring o, as shown in Fig. 8. This deflection may be in either backward or
forward direction according as the locomotive may be running forward or backward.
The springs ss acting on the ball a' through the plate d' resist any deflection of the
lever E and instantly restore it to its normal position when it has passed beyond the
plates (The lever E is permitted to swing laterally, as indicated by the dotted.
lines in Fig. 9, in order that it may adapt itself to the position of the plates ff² in
entering between thein.
This construction of the track plates insures against their being obstructed by snow
or ice to such extent as to prevent making a good electrical contact with the lever E
in its passage.
The lever E may be otherwise hung so as to be capable of universal motion, both
forward and back and in lateral direction, but the ball-and-socket connection shown is
considered the most simple and effective.
My system of signalling is applicable to the ringing of bells in railway stations, or
at road crossings or in tunnels to announce the approach of a train, also for the
automatic operation of gates or signals at road crossings. It is also applicable to
single-track railways instead of double-track_ones, in which case, however, each
signal point L, M, N etc., should be connected not only to a signal point in the rear,
but also to a sigual point in advance in order to warn the drivers of two approaching
engines and prevent their collision.
The danger signal on the locomotive engine may be an electric bell or a visual
signal instead of the whistle h. Any other means may be provided for attracting the
attention of the engine driver, such as by sending an electric shock through his person.
The rear terminal W of the partial circuit cc might be the wheels of the last
carriage or car of the train instead of the wheels of the tender.
In this case any
accidental breaking or uncoupling of the train will break the circuit ee and cause an
alarm to be given to the engine driver.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. Providing the locomotive engine with a partial circuit c c terminating in
wheels B W, or other equivalent connections with the rails, and with a shunt-
circuit d d crossing between the poles of the dynamo G, the current in which shunt is
augmented when the circuit c is broken at y or includes a high resistance, as z.
2. Providing a relay R (or other electro-magnet) in the shunt-circuit dd, adapted
to cause or insure that the danger-alarm shall be given when crossing an open
insulation y, or a disconnected contact rail (.
3. Constructing the partial circuit c c c to include an alarm-magnet A and the
armature-lever e and stop f of a relay R, the coils of which are in the shunt dd,
whereby when the current Howing in this shunt is augmented the circuit e' is broken
at ef, and the current is cut off from the magnet A which thus releases its armature
and gives the alarm.

page_text: 4. Constructing the partial circuit cc with two branches, a branch c² including the
alarm-magnet A and relay contacts ef, and a shunt branch c³ including a resistance Q,
so that while an alarm is being given sufficient current will flow through the
shunt and terminals B W (or B and E) to the rails to transmit a signal to a distant
signalling point.
5. Providing the railway track with track or contact-rails, insulated from each
other and an induction-coil P with the terminals of its primary coil connected to
said rails respectively, and the terminals of its secondary coil connected to wires s s
extending to a distant signalling point, either to operate block signals or for signalling
to a station, etc., to announce the approach of a train.
6. The entire track installation consisting of an insulated rail I (or two successive
insulated contact-rails CC) forming signal-receiving and transmitting points Rc and
Tr, with an induction-coil P having its primary coil connected to T and its secondary
connected by wires ss to an adjacent magnet D and a magnet S at a distant signalling
point, and wires 5 and 6 bridging the insulation at R and closed or broken by a
lever moved by oppositely-acting magnets D and S.
7. The specific construction of the circuit-breaking instrument shown in Fig. 6,
consisting of the magnets D S, with the lever b, the rubbing contact-spring a, the
knife-edge, disk w and it spring w', and with suitable means for adjusting the spring a.
8. In a system of signalling such as is herein before described, providing the
Jocomotive engine or train with a current generator and a partial electric circuit
terminating in wheels or electrodes B W and normally completed through the rails,
and with a circuit-breaker, such as a lever E, adapted to break said circuit when it
is displaced by contact with some part located on or near the track, such as rails or
plates C.
9. In a system of signalling such as is hereinbefore described, providing a railway
track with a contact rail or plate at the point Rc insulated from the track-rails R¹,
and with connecting wires 5, 6, and contact-breakers ab for electrically connecting
with R' for
safety " and breaking this connection to give a "danger" alarm in the
locomotive.
10. In a system of signalling such as is herein before described, the track installation
for transmitting signals from the locomotive consisting of a contact-rail or plate Cat
the point T, insulated from the track-rails R, and with circuit wires p s s p
extending from such plate to a distant signalling point, and returning to the rail R¹,
and including a safety magnet S at the distant point and a danger magnet D at an
adjacent point, (with or without the intervention of an induction-coil P).
1
11. In a system of signalling such as is herein before described, the connection of
contact-lever E to the locomotive by a universal connection, whereby it may swing
laterally to adapt itself to the contact rails or plates on the track, and may be deflected
forward or backward to break contact with the spring o, and having springs for
returning it to its normal position.
12. In a system of signalling such as is herein before described, the construction of
contact rails or plates C, each consisting of two plates 2 pressed together by a
spring and adapted to admit the passage between them of a contact-lever or blade E
carried by the locomotive.
13. The application of my new system of signals to switching or shunting points,
drawbridges, signals at stations and crossings, and single-track railways, all substantially
as described.
DAL 1: 10k 1
M
1 1000
J. C. MEWBURN,
5 & 56, Chancery Lane, London,
Patent Agent.