IMPROVEMENTS IN ELECTRIC SIGNALLING APPARATUS FOR RAILWAYS
Year: 1879

page_text: LETTERS PATENT to William Robinson, Electrical Engineer, of Boston, in the
State of Massachusetts, United States of America, now in London, for the
Invention of "IMPROVEMENTS IN ELECTRIC SIGNALLING APPARATUS FOR
RAILWAYS."
Sealed the 18th November 1879, and dated the 29th August 1879.
PROVISIONAL SPECIFICATION left by the said William Robinson at the
Office of the Commissioners of Patents on the 29th August 1879.
WILLIAM ROBINSON, Electrical Engineer, of Boston, in the State of Massachusetts,
United States of America, now in London. "IMPROVEMENTS IN ELECTRIC SIG-
NALLING APPARATUS FOR RAILWAYS."
This Invention has for its object, chiefly, the automatic operation of electric
signals on railways by means of passing trains, the rails of the track being used as
principal conductors of the electric current.
The first part of my Invention relates to the operation of block and station
signals, and consists in various novel combinations and material improvements
hereinafter described, the whole forming an automatic block signalling apparatus
superior to any heretofore produced.
.
In operating this part of my Invention I divide the track into sections, a mile,
more or less, in length, the sections being insulated from each other. The battery
has its poles connected to the opposite rails of the track at one end of the section,
the magnet which controls the operation of the signal being similarly connected at
the opposite end of the section. The current from the battery keeps the magnet
magnetized until a train comes on the section, when the wheels and axles by short-
circuiting cut off the battery current from the magnet, which is thus demagnetized,
and the position of the signal thereby changed, thus indicating to a following train
the danger ahead. The circuit it will be observed is constant..
For use on a single track road a line wire is used in connection with the rail
circuit, and a signal is placed at each end of the section, whereby the train is
guarded from collision both front and rear. One or more line wires may also be
used to operate additional signals, for instance, to indicate at a station the approach
of a train, or to indicate when the block signal has changed.

page_text: The tearing up of a rail or displacement of a switch or drawbridge will interrupt
the circuit and thereby also indicate the danger. The signal may also be operated
by a hand key, from any station, when desired.
The first part of my Invention embodies an electro-mechanical signal of such
construction as to be controlled readily by an electro-magnet with very little
battery power, no matter how heavy the signal and its mechanism may be; to this
end a series of detents is used, one pressing upon the other near its fulcrum in such
manner that the pressure of the one resting against the armature lever shall be
very slight and the escape easy, however 'much direct power may be required to
move the signal.
This part of the Invention also embodies the combination of an electro mechan-
ical signal, audible or visual, with a constant metallic circuit.
The Invention 'also embraces a method of insulating the rail sections from each
other by using a "truss" joint, upon which the ends of the rails to be insulated
from each other rest, an insulating material being used between the ends of the
rails, and between the rails and the joint.
My Invention also embraces a method of insuring good electrical connection
between the adjacent rails of the signal section, however defective in this respect
the ordinary splicing may be. For this purpose I bore small holes in the flanges of
the rails near the ends, and drive a wire or rivet soldered to a wire securely into
these holes, thus insuring good electrical connection between the adjacent rails.
In a similar manner the battery and other wires are preferably connected to the
rails.
The Invention also embraces a connection for switches and drawbridges, whereby
the displacement of a switch or of a drawbridge bolt in the slightest dangerous
degree will control the circuit and indicate the danger. For this purpose elastic
wires or springs are used; said springs are in the circuit, and are connected or
disconnected by a metallic plug attached to the switch, switch bar, or drawbridge
bolt, whereby the movement of said plug will operate the signal by short-circuiting
or by opening the circuit, either or both. The lock of the switch or drawbridge
may be so connected to the signal mechanism as to expose the danger signal by
controlling the circuit when the switch or 'drawbridge is left unlocked.
In this Invention the signal mechanism is operated by a weight or spring, said
mechanism being released or controlled in its action by an electro magnet.
A battery changing attachment is sometimes made to the electro mechanical
signal mechanism, whereby each change of the signal will act upon a spring switch
and throw one section of battery out of circuit and another in, thus prolonging the
duration of the battery by allowing sections of it to alternately rest and work. An
electro mechanical battery changer may be made, when necessary, independent of
the signal mechanism.
The peculiar arrangement of detents described is suitable for operating'other
tlian signal mechanism; for instance, it may also be used to release heavy fire-
alarm or other telegraph mechanism.
The second part of my Invention is a modification of the first. In this a section
of rails is used as before; the battery has one pole connected to one of the rails and
the other pole connected to earth, while the magnet has one electrode connected
to the other rail and the other electrode to earth. The train will by its wheels and
axles close the circuit between the rails, and thus operate the 'signal.
The third part of my Invention relates to the operation of a bell or other signal
on a locomotive or train when the track ahead is clear and safe. To this end ta
section of track is used as before, a battery being connected to the opposite rails at
one end of the section. At the other end of the section is placed an extra rail or
metallic platform, electrically connected to one rail of 'the section. The magnet
controlling the bell or signal on the engine has one'electrode in electrical connection
with the wheels, and the other in 'connection with an insulated metal brush or
other suitable device on the engine. When the engine approaches the section, the

page_text: wheels connect with one rail of the same, and the metallic brush with the extra
rail, whereby the circuit is completed, through the magnet of the signal on the
engine, thus notifying the engineer if the track, say, within a mile or two ahead, is
clear and safe. If it be occupied by a train or pair of wheels, or if a rail be torn
up, the electric current will be, cut off, and the engineer will thus, in the absence of
a positive signal of safety, know of danger ahead.
By the term "constant circuit" I mean a circuit in which the magnet is con-
trolled without actually opening the circuit, as by short circuiting.
By the term "electro mechanical signal" meant a signal moved mechanically,
as by a weight or spring, the mechanism being released or controlled by means of
an electro-magnet.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robinson in the Great Seal Patent Office on the 21st
November 1879.
WILLIAM ROBINSON, Electrical Engineer, of Boston, in the State of Massachusetts,
United States of America, now in London. "IMPROVEMENTS IN ELECTRIC SIG-
NALLING APPARATUS FOR RAILWAYS."
This Invention has for its object chiefly the automatic operation of electric signals
on railways by means of passing trains, the rails of the track being used as prin-
cipal conductors of the electric current.
The first part of my Invention relates to the operation of block and station
signals, and consists in various novel combinations and material improvements
hereinafter described, the whole forming an automatic block signalling apparatus
superior to any heretofore produced.
In operating this part of my Invention I divide the track into sections, a mile,
more or less, in length, the sections being insulated from each other. The battery
has its poles connected to the opposite rails of the track at one end of the section,
the magnet which controls the operation of the signal being similarly connected at
the opposite end of the section. The current from the battery, keeps the magnet
magnetized until a train comes on the section, when the wheels and axles by short
circuiting, cut off the battery current from the magnet, which is thus demagnetized,
and the position of the signal thereby changed, thus indicating to a following train
the danger ahead. The circuit, it will be observed, is constant. For use on a single
track road a line wire is, used in connection with the rail circuit, and a danger signal
is placed at each end of the section, whereby the train is guarded from collision
both front and rear. One or more line wires may also be used to operate additional
signals, for instance, to indicate at a station the approach of a train, or to indicate
when the block signal has changed. The tearing up of a rail or displacement of a
switch or drawbridge will interrupt the circuit and thereby also indicate the
danger. The, signal, may also be operated by a band key, from any station when
desired;

page_text: The first part of my Invention embodies an electro-mechanical signal of such
construction as to be controlled readily by an electro minagnet, with very little
battery power, no matter how lieavy the signal and its mechanism may be. To this
end a series of detents is used, one pressing upon the other near its fulcrum in such
manner that the pressure of the one resting against the armature lever shall be very
slight and the escape easy, however much direct power may be required to move
the signal.
This part of the Invention also embodies the combination of an electro mechanical
signal, audible or visual, with a constant metallic circuit.
The Invention also embraces a method of insulating the rail sections from each
other by using a "truss" joint, upon which the ends of the rails to be insulated*
from each other rest, an insulating material being used between the ends of the
rails and between the rails and the joint.
My Invention also embraces a method of insuring good electrical connection
between the adjacent rails of the signal section, however defective in this respect
the ordinary splicing may be. For this purpose I bore small holes in the flanges of
the rails near the ends, and drive a wire or rivets soldered to a wire securely into
In
these holes, thus insuring good electrical connection between the adjacent rails.
a similar manner the battery and other wires are preferably connected to the
rails.
The Invention also embraces a.connection for switches and drawbridges whereby
the displacement of a switch or of a drawbridge bolt in the slightest dangerous
degree will control the circuit and indicate the danger. For this purpose elastic
wires or springs are used; said springs are in the circuit and are connected or
disconnected by a metallic plug attached to the switch, switch bar, or drawbridge
bolt, whereby the movement of said plug will operate the signal by short circuiting
or by opening the circuit, either or both. The lock of the switch or drawbridge
may be so connected to the signal mechanism as to expose the danger signal by
controlling the circuit when the switch or drawbridge is left unlocked.
In this Invention the signal mechanism is operated by a weight or spring, said
mechanism being released or controlled in its action by an electro-magnet.
A battery changing attachment is sometimes made to the electro mechanical
signal mechanism whereby each complete change of the signal will act upon a spring
switch, and throw one section of battery out of circuit and another in, thus pro-
longing the duration of the battery by allowing sections of it to alternately rest and
work. An electro mechanical battery changer may be made when necessary inde-
pendent of the signal mechanism.
The peculiar arrangement of detents described is suitable for operating other
than signal mechanism; for instance, it may also be used to release heavy fire alarm
or other telegraph mechanism.
The second part of my Invention is a modification-of-the-first. In this a section
of rails is used as before, the battery has one pole connected to one of the rails and
the other pole connected to earth, while the magnet has one electrode connected to
the other rail and the other electrode to earth. The train will by its wheels and
axles close the circuit between the rails; and thus operate the signal.
The third part of my Invention relates to the operation of a bell or other signal on
a locomotive or train when the track ahead is clear and safe: To this end a section
of track is used as before, a battery being connected to the opposite rails at one
end of the section. At the other end of the section is placed an extra rail or
metallic platform electrically connected to one rail of the section. The magnet
controlling the bell or signal on the engine has one electrode in electrical connection
with the wheels, and the other in connection with an insulated metal brush or other
suitable device on the engine. When the engine approaches the section the wheels
connect with one rail of the same and the metallic brush with the extra rail, whereby
the circuit is completed through the magnet of the signal on the engine, thus
notifying the engineer if the track, say, within a mile or two ahead, is clear and
safe. If it be occupied by a train or pair of wheels, or if a rail be torn up, the

page_text: electric current will be cut off and the engineer will thus, in the absence of a positive
signal of safety, know of danger ahead.
The details. of my Invention will be more fully described hereinafter in
connection with the Drawings. It may be premised however that by the term
"constant-circuit," I mean a circuit in which the magnet is controlled without
actually opening said circuit as by short circuiting.
Also by the term "electro-mechanical signal" is meant a signal moved
mechanically as by a weight or spring, the mechanism being released or controlled
by means of an electro-magnet.
In the accompanying Drawings which form a part of this Specification, Figures
1 to 12 inclusive refer to the first part of my Invention. Similar letters of
reference indicate corresponding parts.
Figure 1 is a plan of the signal section on one track of a double track road;
Figure 2, a plan of the section on a single track road; and Figure 3, a plan of the
signal section including a switch; Figure 4 is a perspective view of the signal
mechanism; Figure 5, an obverse face view of the same showing the arrangement
of detents, and Figure 6 is a section of the mechanism showing an edge view of the
detents; Figure 7 is a battery changer; Figure 8 is a plan of the switch and draw-
bridge connection; Figure 9 shows the wire for connecting adjacent rails together
electrically; and Figure 10 shows an elevation of two rails connected by said wire;
Figure 11 is an elevation, and Figure 12, a cross section showing the mode of
insulating adjacent rails from each other.
l
T is a section of railroad track, a mile, more or less, in length, having electrical
continuity throughout its length, and insulated from adjacent sections at the
joints a, b, c, d. At one end the battery B has its poles connected to the opposite
rails e, f, of the section T by the wires g, h, as shown, while at the other end of the
section, the magnet M has the ends of its coils connected also to the opposite
rails e, f, of the section by the wires i, k, thus preventing a complete metallic circuit
to the electric current, which is thereby kept from passing to earth even during rain,
snow, and slush.
The magnet M. controls the operation of the signal. The signal
disc A on the vertical shaft C is arranged to turn one quarter around and back
again. This is accomplished as follows (see Figures 4, 5, and 6). The toothed
wheel D supported in its frame gears into the pinion on the shaft m.
On one
end of the shaft m is the crank n, which is connected to the post p by the rod o
which is pivoted at p. The crank r on the shaft C is attached to the post p by the
connecting rod q, said connecting rod being pivoted at both ends as shown. The
post p is rigidly attached to the rods 8 and t, which rods slide through the guide
plates u, v on the end of the shaft m opposite n is attached the detent w, which
presses against the detent w' near the pivot of the latter, whereby the pressure of
the detent w against the pin a' of the armature lever E is very slight, however
great the weight used to turn the geared wheels. The weight W is attached by a
cord or chain to the shaft F. The detent w' has one end a little longer than the
other, so that when the armature is away from the magnet the short end c¹ of said
detent engages with the pin a¹ of the lever E; but when the magnet attracts its
armature the pin a' is raised, and the short end c¹ of the detent escapes under said
pin; the detent w³ is now caused by the pressure of the detent w to make a half
revolution, when the long end d' engages with the pin a¹. When the magnet lets
go the armature, the long end d' of the detent w escapes over the pin a¹ of the
arinature lever, and said detent w¹ is caused to make another half turn, thus
having made a complete turn by the alternate magnetizing and demagnetizing of
the magnet M.
The operation of the signal mechanism is as follows:-When the magnet M is
either magnetized or demagnetized the armature lever E is reversed, in the one
case by the direct force of magnetism, and in the other by the retractile force of the
spring b; in either case the pin a' of the armature lever is withdrawn froin the
detent w, which is thus left free to escape; now the weight W acting on the shaft
F turns the wheel D, and this wheel gearing into the pinion turns the shaft m

page_text: with its detent w half way around, and the detent w turns the detent w¹ also half
way around until the other end of said detent w¹ engages with the pin a' of the
armature lever E; and thus stops the further action of the mechanism. When the
shaft m makes a half turn the crank n attached to it also of course makes a half
turn, and this acting through the rod o, post p, aud connecting rod q on the crank r
causes the shaft C to make a quarter turn, whereby the signal disc is caused to
present. a full face or edge view as the case may be. It will be observed that the
connecting rod q is so geared with the crank r that a half turn of the crank n will
cause but a quarter turn of the crank r.
:
When this signal is connected to the track the operation is as follows:-The
current from the battery B passing along the rails e, f, of the section T to the
magnet M keeps the magnet magnetized and the signal concealed or in a position
indicating safety; when however the train approaching, say, in the direction of the
arrow X, enters upon the section, the wheels and axles thereof cut off the current
from the magnet M by short circuiting, because, by reason of their greater mass,
they are better conductors than the small wire of said magnet, the magnet M being
thus demagnetized lets go its armature, and the signal is reversed or thrown into
a position indicating "danger" in the manner already described. The signal it is
evident continues to show "danger" to a following train as long as the first train
or a single car remains on said section. As soon however as the whole train has
passed off the section the current again reaches the magnet M and instantly
reverses the signal, causing it to indicate "all clear" for the next train.
The signal may also be operated by a hand key G at any suitable station when
desired. It will be observed also that if a rail of the section be torn up through
mischief or for repairs, or if it be broken so as to separate the metallic continuity,
the circuit will be interrupted, the magnet thereby discharged, and the danger
signal shown.
In Figure 2 the magnet M is caused to control an additional signal at M' through
the line wire L, whereby signals are simultaneously shown at M and M², one at
each end of the section, so that a train is thereby protected from collision on a
single track road by a signal both front and rear.
The switch connection is shown in Figures 3 and 8; H is a cast iron box placed
on the end of an ordinary sleeper and connected to the switch by its sliding bar N.
The box H contains insulating blocks I, I, and K, K, to which are attached the wire
or metal springs 1, 2, 3, 4. The sliding bar N has two metal blocks or plugs 5, 6,
attached to it; the plug 5 connects the springs 3, 4, electrically; when the bar N is
drawn out, and disconnects said springs when the bar is thrust in, whereas the
plug 6 connects the springs 1, 2, when the bar N is thrust in, and disconnects them
when the bar is drawn out; the plug 6 is insulated from the bar N. The wire 7
from the rail e at one side of the switch is connected electrically with the springs
2 and 4, while the wire 8 from the other side of the switch beyond the insulation a³
is connected to the springs 1; the wire 9 from the rail is connected to the
-springs 3. Now it will be seen that when the bar N is drawn out by displacing
the switch, even in a slight degree, the plug 5 brings the springs 3, 4, into electrical
connection, and thus, through the wires 7 and 9, connects the rails e and f in short
circuit, thus cutting off the current and discharging the magnet M, and thereby
showing the danger signal. At the same time that the plug 5 connects the springs
3, 4, the plug 6 disconnects the springs 1, 2, thereby breaking the electrical con-
tinuity of the rail e; this of itself would be sufficient to demagnetize the magnet
and expose the danger signal, but when we both open the circuit and short circuit
the current the assurance of correct working is absolute. It will be observed that
the plug 5 may be brought in contact with the springs 3, 4, when the switch has
been displaced half an inch if desired, and the contact continues throughout the.
whole throw of the switch and until it is again restored to the main line. At the
same time a slight throw of the switch disconnects the springs 1, 2, which remain
disconnected until the switch is fully restored. The springs 3, 4, &c., consist of a
series of wires placed one above the other, and the series soldered to the metal.

page_text: blocks 11, 12, The crossing rail of the switch is insulated at 6%, and one of the
main line rails may be insulated at each side of the switch a, e, when necessary to
prevent the current being cut off by the switch rods. The wire f is simply to
insure good connection around the switch on the rail f. The switch rails may be
insulated at c, d, and the rail e be connected electrically to the switch rail g², as
shown in dotted outline h²; in this case if a carriage be left on the siding too near
the main track the wheels and axles will cut off the current by short circuit, and
thus expose the danger signal.
For a drawbridge the sliding bar N of the box H is connected to the draw bar of
the bridge, so that moving said draw bar will control the circuit in the manner
already described, and expose the danger signal before the bridge is opened.
When the battery is used on continuously closed circuit it deteriorates more
rapidly than when the circuit is open a part of the time. To obviate this deteriora-
tion I duplicate the battery and use a battery changer, shown in Figures 4 and 7.
The cam is fixed to the shaft ks, and the spring plates m², n², are alternately
raised from the anvil o² by said cam as it revolves. When the spring plate m
rests against the anvil o², the circuit is complete through said plate and anvil, the
conductors p³, q², 2, 8, 12, the magnet M², and the battery B, but when the cam 2
has made a half turn it raises the spring m from the anvil 02, and allows the
spring n² to press against said anvil; thus the spring m", the conductor t, and the
battery B are switched out of circuit, and the spring n², conductor u², and
battery B are brought into circuit. The cam 2 is so arranged that one battery is
brought into circuit before the other is thrown off, that there may be no interrup-
tion of the current through the magnet. To the shaft m is fixed the toothed
wheel, which gears into the toothed wheel w² on the shaft ²; w has twice as
many teeth as v², whereby one complete revolution of the wheel v² makes only half
a revolution of w aud of the cam 2, that is, one complete exposure and return of
the signal A is necessary to make half a revolution of the cam 2³, and to change
the battery. Simply the principle and manner of changing the battery are here
shown; ordinarily, when signals are used on successive sections, one signal is caused
to change the battery belonging to the next section of track. By changing the
batteries in this way, allowing one to rest and recuperate while the other is in
action, the duration of the batteries is multiplied several fold. A signal battery
will readily last four to six months without cleaning or renewing, and a single
cell of battery will operate a large sheet iron outdoor signal through a mile section
of track without the intervention of a relay and regardless of weather.
Good electrical connection is secured between the adjacent rails, when necessary,
as shown in Figures 9 and 10. A³ is a wire wrapped around the rivets a³, a³, and
soldered thereto; the rivets a³, a³, are then securely driven into small holes drilled
in the flanges of the rails B³, B³, forming a reliable connection as shown.
The battery wires and magnet wires are connected to the wire A³, and thus
securely connected to the rails.
When necessary to repair the track, the rivets a³,.a³, may be drawn out or cut off.
A hole the proper size for the rivets can be drilled through the flange in less than
three minutes.
"
The mode of insulating the rails from each other is shown in elevation in
Figure 11, and in cross section in Figure 12. In Figure 11 the flange (b³, Fig. 12).
is removed for convenience of illustration. C³ is a truss joint resting on the
sleepers F3, F3, as shown; d³ is a sheet of "vulcanized fibre placed between the
joint plate C3 and the bottoms of the rails D³, E3, effectually insulating said
plate from the rails; f³ is a piece of the same material placed between the ends
of the rails; and e³, es, are also pieces of the vulcanized fibres placed between
the flanges of the rails and the forclocks g³, g³. The forelocks g³, g³, which are three
or four inches in, length, press upon the tops of the flanges of the two rails D³, E³, at
their point of junction, but are insulated therefrom by the aforesaid vulcanized
fibre e, e. The forelocks are held in position by a single U bolt Gs passing through-
near the centre of the plate C³ and of the forelocks g³, g; the whole is securely

page_text: screwed together by the nuts, 3. When, necessary thimbles of the vulcanized
fibre are placed around the bolt G3 where it might come in contact with the rails.
The plate C is spiked down to the sleepers, thus it will be seen the two rails D³, E³,
are effectually insulated from each other. Any suitable insulating material may be
used, but I prefer so-called "vulcanized, fibre" because it is exceedingly hard and
durable, and a joint insulated in this way is not only not deteriorated but it is
actually superior to the usual fished joint for ordinary railway uses.
The signal disc A may be of red cloth or glass capable of illumination, and
enclosed in a box with a glass orifice, the whole arranged so that at night the cloth
or glass disk, swinging in front of a lamp,. will give a red light, but when the disk
is removed the light will be white, indicating safety; or the signal disk may be of
sheet iron, swinging in the skeleton frame H³, Figure 13, the signal mechanism
being enclosed in the box 13, and a suitable arrangement being made to give a red
and white light alternately at night. It is evident also that the signal may be of
any shape, and may be in any desired position, as the mechanism is readily adapted
to work it in any case.
Figures 14 to 18 inclusive refer to the second part of my Invention and show
plans of sections of railroad track with batteries and magnets connected to the
sections. In this part of my Invention the signals are operated on a normally open
circuit.
In Figure 14 the battery B has its poles connected to the opposite rails e, f, at
one end of the track section as already described, while at the other end of the rail
line e a ground wire g is attached to said rail line; also the magnet M³ has one
coil attached to the short rail section et by-the wire at, and the other coil connected
to earth by the ground wire 95. When the train approaching the section in the
direction of the arrow crosses the insulated joints d, b, the circuit is completed
through the wheels and axles, rail sections e, f, es, battery B, magnet M³, and
ground wires g', 95, whereby the signal whose norinal condition is " danger" is
changed in the face of the engine driver to "safety;" but as soon as the wheels and
axles have reached and connected the rails e, f, the current is cut off from the
magnet by short circuit, and the signal instantly goes to danger again, from which
it cannot be removed by a following train until the first train has wholly passed off
from the rail sections e, f.
In Figure 15 the magnet M' has one end of its coil connected to the rail line e,
and the other end to the ground wire c', while the battery B' has one pole
connected to the rail line f, and the other pole to earth by the ground wire d'
When a train enters upon the section its wheels and axles close the circuit, and
thereby operate the signal at-M⭑. When the train passes towards the right this
arrangement may be used for block signalling, or when the train passes towards the
left the magnet M* may be used to operate a bell at a station to announce the
approach of a train.
Figures 16 and 17 are modifications of the arrangement shown in Figure 15,
illustrating how a single battery may be used economically to operate several
signals successively or conjointly. The battery is connected as before, one pole to
the ground, and the other pole to the rail section f; but the section f is as long as
several sections e, e, i, of the opposite rail; while to each of these sections e, h, is,
a magnet is connected; in Figure 10 one electrode of the magnets M, M*, M**, is
connected to the rail sections c, h, 2, respectively, while the other electrode is
connected to earth by ground wires, as shown; in Figure 17 the magnets M' and
ML have their electrodes connected respectively to the adjacent rail sections e, h³,
and,, while the magnet M** has one electrode connected to the rail section i*,
and the other to earth by the ground wire. When a train enters upon the section
Figure 16 from the left, it closes the circuit and operates the signals successively at
M** M*, M, leaving them exposed behind as block signals; but if the train run
from the right it will reverse this process, and operate the signals successively in
advance, beginning with M.
A train entering upon the section Figure 17, say from the right, operates the
"

page_text: series of signals simultaneously at different stations in advance as shown. It will
be observed that in connection with Figures 16 and 17 but one battery is used to
operate a series of signals; the battery is on open circuit except when the train or'
a car is present to close the circuit by its wheels and axles bridging the rails.
'
Figure 18 shows a modification suitable for giving a signal to a gate-keeper, or'
at a road crossing on a level in which a train approaching on either track operates
the signal; as before the battery and magnet have one side connected to earth; the
battery has the other side or pole connected to one rail of each of the track sections
T, T', and the magnet has one electrode connected to the other rails of said track'
sections as shown. A train approaching on either section T or T¹ operates the'
signal at M
+
The remaining Figures 19 to 22 inclusive, refer to the third part of my Invention,
operating a signal on a locomotive or train, when the track ahead is clear and safe.
Figure 19 is a perspective view showing this part of my Invention as applied to a'
plain track; Figure 20 is a top view showing it as applied to a single track road,
Figure 21 as applied to a switch, and Figure 22 shows a combination of the block'
and train signal.
[
T is a section of railroad track, a mile, more or less, in length. The rail lines e, f,
of this section have metallic continuity throughout their length, and are separated
from metallic contact with the adjacent sections by the insulated joints a, b, and
c, d. The battery B is connected to the rail lines e, f, at one end of the section by
the wires g, h, as shown. Parallel with the rails of the track, and a short distance.
therefrom, is placed the rail or metallic plate H³ at the other end of the section,
said rail H being electrically connected to the rail line f by the conductor ho. The
end of the rail H³ is preferably opposite, or nearly so, to the opening c in the rail
line e; the opening d in the rail line f being nearly the length of the rail H in
advance of the opening c of the rail line e L represents a locomotive or car on
which is placed the bell N5, operated by the magnet M³, said magnet having one
electrode electrically connected to the axle 05 of said locomotive by the wire 1,
while the other electrode is connected by the wire m³ to the metallic brush P5,
which is attached to the locomotive, but insulated from the axle 05. When the
locomotive is off section T, the circuit from the battery B is open, as shown in
Figure 19; but when the locomotive has reached section T, a complete metallic
circuit is presented as follows:-Battery B, wire g, rail line e, wheels and axles 0,
wire 1, magnet M5, wire m³, brush P5, which comes in contact with rail H³, thence
by rails H, f; and wire h to the battery B, completing the circuit. It will be
observed that the circuit through the magnet M³ will be complete, and the bell No
be rung when the brush P5 is in contact with the rail H³, that is, while the loco-
motive.is passing the rail H5. If there be another train however on the section T,
as at O*, the wheels and axles thereof; by reason of their superior conductivity, will
short circuit the current from the battery B, thus cutting off the current from the
magnet M, and preventing the sounding of the alarm N while the locomotive is
passing the rail H. 'By this arrangement, the engineer of the locomotive L³ always'
receives a positive safety signal when the track ahead is all clear and safe, the
absence of such signal being evidence of danger ahead.
Figure 21 illustrates the arrangement for signalling when a switch is found
within the signal section. In this case an insulated joint is made at a², a³, each
side of the switch, and also at 62 on the crossing rail, so as to separate the rails e, f,
from metallic connection with each other. A wire from the rail at the left of the
joint a runs to the plate c", and a wire from the plate 5 connects with the rail at
the right of the joint a³. A connection k³ attached to the switch makes electrical
connection between the plates c, d. Thus the switch is cut out, and a wire running
around it connects the rails at each side of it, leaving the circuit ready to operate
the signal on a train reaching H³, as already described. An insulation 66 is made in
the siding rail e* near the head block of the switch, and a wire connects said siding
rail with the plate f³ at the switch. Now when the switch is thrown over to
the siding; the plate ³ leaves the plate d³, and connects with the plate ƒ³, whereby

page_text: that part of the main track to the right of the switch is, thrown out of circuit, and
the siding rails.e*, f*, are brought into circuit, so that a train reaching H
* on the
siding will receive the signal from the battery B, and thereby be notified that the
track ahead beyond the switch is clear, and that the switch is placed for the
siding.
Figure 22 shows a combination of the block signal, described in connection with
the first part of my Invention with the train signal. The magnet M of the block
signal operates as already described. By making the magnet M of the train signal
of equal or less resistance than the magnet M; when the train reaches H³, the
current from the battery B is divided; the magnet M³ draws, off a large proportion
thereof from the magnet N, and thus operates the signal on the train. When
the wheels and axles connect the rails e, f, the magnet M is wholly demagnetized,
and the danger signal exposed. Thus an engineer receives a safety signal on his
engine, and leaves a danger, signal exposed on the road side behind his train.
Figure 20 shows a superior arrangement for signalling on single track roads. In
this arrangement batteries K2, K³, K, are placed at intervals of, say, a mile or two
apart with their poles connected to the opposite rails of the track, as already
described. Near to the batteries are placed the supplemental rails H²*, H³*, H**,
H³*, H, H7, and the rail lines are divided into sections by the openings a²*, 62,
a3ª, 63*, a**, **. The supplemental rails have one end permanently connected to
the regular rails of the track by the conductors h³, while the other end of said.
supplemental rails is connected to an adjacent rail section of the track by a circuit
closer, which, in its normal condition, is closed. To illustrate :-The rail H2* is
permanently connected to the rail section C5 by h³, while the opposite end of H2*
is connected by the circuit closer h6 to the rail section Co. In a similar manner H³*
is permanently connected to B, and connected by the circuit closer h' to B³. The
other supplemental rails are similarly electrically connected to the adjacent sections
of the rail lines. Thus it will be seen that various signal sections are in electrical
connection with each other through the supplemental rails. The mode of operation
is as follows: Let a train approach the signal sections in the direction of the
arrow y; when the wheels and axles reach the point a³, a³, they short circuit the
current of the battery K2, and at the same time the circuit closer his temporarily
opened by the pressure of the wheel, or preferably by the deflection of the rail B³,
or in any suitable manner. Simultaneously the brush P5 of the locomotive comes
in contact with the rail H3*, completing the circuit through rails H3*, B6, battery K³,
rails HC, wheels of the locomotive, magnet M³, and brush Ps aforesaid, thus
ringing the bell on the locomotive. When the train reaches the point a, a, the
battery K³ is cut off by short circuit, the circuit closer 8 opened; and the locomotive
signal operated through a current from the battery K'.
Now suppose the track to be clear and a train to approach from the opposite
direction, moving in the direction of the arrow z. When it reaches the point a', a³,
the battery K is cut off by short circuit, the circuit is opened through the circuit
closer, the brush of the locomotive connects with the supplemental rail He, and
the bell on the locomotive is operated by a current from the battery K³. In like
manner when the locomotive reaches the point as, as, the battery K³ is cut off, the
circuit opened at h*, the brush connects with the rail H**, and the bell is operated
by a current from the battery K. By this arrangement it will be observed that
in whichever direction the engineer may be going he will receive a signal when the
track ahead is clear. It is further evident that should there be a train or, car on
the section, or a rail be torn up, an engineer approaching either end of the section
cannot receive a safety, signal from the opposite end. The circuit closers he, h7, &c.,
are only temporarily opened. They close again automatically when the train has
passed. The supplemental rails H**; H*; &c., may be placed on opposite sides of
the track, as shown, or, on the same side, according to convenience; they will
answer the purpose equally well either way.
Having, thus described my Invention I wish, it, understood, that I do not limit
myself to the exact details of the description. Variations may be made without

page_text: affecting the spirit of the Invention'; thus, where a visual signal is described in
connection with the track an audible signal may be substituted where found
advantageous, and an additional signal, either audible or visual, may be used either
in the same or in an additional circuit. Furthermore, 'the signal mechanism shown
in Figure 4 'may be used to advantage sometimes in a circuit controlled exclusively
by hand, or it may be used in connection with any 'interlocking switch system and
have a repeating attachment to repeat back the exact position of the signal. Other
variations in the details of 'constructing and using 'my signalling apparatus may be
made.
What I claim as my Invention 'is,—
First. The combination of a constant 'circuit, 'a 'magnet or magnets operated or
controlled without actually opening the circuit of said magnets, and an electro
mechanical railway signal or signals, substantially as described.
Second. An electro mechanical visual or semaphoric signal in combination with a
constant circuit composed in part of a rail or rails of a railroad track, 'substantially
'as'set forth.
Third. In combination a constant circuit composed in part of a section of railroad
track 'and two electro-mechanical signals placed one at each end of said section,
substantially as and for the purpose described.
Fourth. The key G in combination with the conductors 7, n, the rail sections e, f,
and the stationary battery B connected to said rail sections, whereby the current of
said battery will be short circuited by manipulating said key and thus be prevented
reaching the signal magnet, substantially as described.
Fifth. In an electro mechanical movement, 'the detents wand w¹ so related to
each other as to relieve the pressure upon the armature lever E, substantially as
shown and described.
'Sixth. In an electro mechanical movement 'the cranks n and with the connecting
rods o, q, (either or both) and suitable guides s, t, the whole in 'combination with
the shaft C, substantially as and 'for the purpose described.
Seventh. An electric signal mechanism constructed substantially as described in
connection with Figures 4, 5, and 6.
Eighth. An electro-mechanical battery changer constructed substantially as
described in connection with Figure 7.
Ninth. A switch or drawbridge electrical connection consisting of the series of
springs 1, 2, and 3, 4, (either series or both) with suitable connecting plugs 5, 6, the
whole operating substantially as shown and described in combination with an
electric signal or signals.
Tenth. The wire A³ in combination with the rails B³, B³, and securely fastened
thereto, for the purpose described.
Eleventh. In combination the wire A³, the rails B³, B³, and the rivets a³, a³, the
whole arranged substantially as described for the purpose of securing electrical
continuity between said rails.
Twelfth. In combination the insulating material d³, the truss or base plate C³,
and the rails D, E³, all arranged as described, whereby metallic contact is prevented
between said base plate and the bottoms of said rails.
Thirteenth. In combination the insulating material e³, e³, placed between the
flanges of the rails and the forelocks g³, g³, for the purpose of preventing metallic
contact between said rails and said forelocks, substantially as described.
Fourteenth. In combination the insulating material d³, es, f³, the base plate C³,
the forelocks g³, and the rails DS, E³, the whole arranged substantially as described
for the purpose of securely insulating the rails D³, E³, from each other.
Fifteenth. The method of operating electric signals, substantially as described in
connection with Figure 14.
Sixteenth. The method of operating electric signals, substantially as described in
connection with Figures 15, 16, and 17.
Seventeenth. The method of operating a road crossing or other signal by means

page_text: of a train approaching on. either track, substantially as described in connection with
Figure 18.
Eighteenth. A magnet suitably arranged on board of a locomotive or car for the
purpose of actuating or controlling a signal on said locomotive or car, said magnet
depending for its operating current on a stationary battery connected to a section
of rails, substantially as described.
Nineteenth. The rail or metallic plate H5 electrically connected to the rail
section in combination with said rail section f and the stationary battery B, also
connected to said section f, whereby a current from said battery passing through
said rails and H will actuate or control a signal on board of a locomotive or car
when the latter makes connection with said rail H³, essentially as described.
Twentieth. The rail sections e, f, and the stationary battery B in combination
with the magnet M³ on the locomotive or car L³, the whole arranged so that the
magnet M5 will be actuated by a current passing from said battery through said
rail sections e, f, substantially as described.
Twenty-first. The block or stationary signal actuated or controlled by a current
passing through a circuit formed partly of the rail sections e, f, in combination with
a signal actuated or controlled by the magnet M³ on a locomotive or car, substan-
tially as described.
Twenty-second. A section of railroad track and two batteries placed at opposite
ends thereof and electrically connected thereto, substantially as shown in Figure 20,
in combination with each other and with a signal-operating magnet M on board: of
a locomotive or car, as shown, the whole, arranged in such manner that when said
locomotive. reaches one end of said section of track it will cut off the battery at
that end of the section by short circuiting or by opening the circuit (either or both)
and at the same time receive an electric current through said magnet M5 from the
battery at the opposite end of said section of track, the whole operating substan-
tially as and for the purpose described.
Twenty-third. The supplemental rail or plate H2* permanently connected to the
rail section C5 and portably connected to the rail section C by the circuit closer º,.
essentially as and for the purpose set forth.
In witness whereof, I, the said William Robinson, have hereunto set my hand
and seal, this Nineteenth day of November, A.D..1879.
WILLIAM ROBINSON. (L.S.)
Witness,
JAAZANIAH BASSETT.