Year: 1888

page_text: A communication from abroad by THE PENNSYLVANIA STEEL COMPANY, of Steelton,
Pennsylvania, United States of America.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester, both in
the County of Lancaster, and 323, High Holborn, in the County of Middlesex, Civil
Engineer, do hereby declare the nature of this invention to be as follows:-
The invention consists in an automatic block signal system as a whole, and in an
improved signal instrument which is adapted for use not only in the block system but
also in other places as will hereinafter appear.
The signal instrument embraces as its fundamental features a semaphoric or visual
signal, an electric motor, intermediate gearing through which the motor operates the
signal in a positive manner, and an automatic switch by which the current through
the motor is arrested when the signal reaches its limit of movement in either
direction.
A railway track is divided into imaginary lengths or sections, commonly known
as "blocks." At each junction of the adjacent blocks a semaphoric or similar visual
signal of any suitable form adapted to be seen by engineers or others controlling the
trains is placed. To the respective signals are connected by intermediate gearing,
suitable electric motors, by means of which they are positively moved to each of their
required positions. The motors may be of any appropriate type known in the art.
Each motor is also geared to and operates an automatic rotary switch controlling the
course of the current, and determining which of the signals shall be operated and the
direction of the movement, as hereinafter recited in detail.
At the end of the respective blocks are located magneto-electric generators or
lynamo-electric generators, each provided with suitable track connections, commonly
known in the art as *
track-levers," of which there are many forms in existence,
through which the generator is actuated or set for automatic action by passing trains.

page_text: so as to produce a prolonged current or succession of currents. Each generator is
connected by suitablo conductors with the motor of the adjacent signal through the
automatic switch of the latter, and from the switch of each signal conductors are also
extended to the next signal to the rear at the opposite end of the block. The arrange-
ment, presently to be recited, is such that the current from each generator is applied
to the motor of the adjacent signal to set the same at "danger" and also applied,
preferably at a later moment, to actuate the motor at the rear of the block to set its
signal to "safety."
The operation is as follows:-
"
Assume that a train moves to the left over the road, and that a train is upon the
right hand block. At this time the signal at the end of the block in rear of the train
stands at "danger" to prevent another train from entering the block at the same time,
and, if the next section ahead is clear its rear signals in front of the train will stand
at safety." As the train-enters the middle block; it sets its generator in motion,
and the current from the latter is immediately applied through a switch to a motor,
which turns the middle signal to the "danger" position. During this action the
automatic switch is turned, and when the signal reaches the "danger" position the
current is diverted from the motor to the distant or rearmost motor which moves
the rear signal to "safety," thus informing the following train that the first train has
passed from the right hand block to the middle block, and that the former is clear.
This operation is repeated at the end of each block, each train setting the danger
signal as it enters a block, and setting the safety signal at the rear end of the block
as it leaves the same at the opposite-end.
"
In certain cases where trains are very long, or the blocks very short, the front end
of the train acting upon the generator will set the signal at the rear of the block at
'safety," while the rear end of the train is still in dangerous proximity thereto. To
avoid this difficulty supplemental devices are provided, which serve to open and keep
open the circuit leading to the signal in rear of, the train until the rear end of the
train has left that block or section. This effectually prevents the signal at the rear
end of the block from being set to "safety" until the train has passed from the
opposite end of the block.
In this form of apparatus the blocks or sections of track are insulated from each
other and the two rails at the rear end of each section connected with each other by
a conductor, through a battery. At the opposite ends the respective rails are con-
nected by conductors leading to an electro-magnet, which attracts an armature,
forming or operating a switch through which the current passes to the rear signal.
When the section clear, that is to say, without trains upon it, the circuit is com-
pleted through the battery at the rear, the two rails, and conductors in front to the
armature, which keeps the signal circuit closed at the magnet. When, however, a
train or any portion of a train stands upon the section, the battery is short-circuited
through the wheels and axles of the train from one rail to the other, so that the
magnet is discharged and the armature retracted by springs so that the circuit to the
rear signal is opened and kept open in such manner that although the generator may
be set in action and the switch of the middle signal properly turned, the rear signal
cannot be set to "safety" until the rear end. of the train leaves the section and allows
the magnet to again close the circuit. A like arrangement is used in each block or
section.
Having now described the general organization and operation of the system, the
details of the generator, signal and switch, will be described as far as may be necessary
for present purposes.
The generators, signals and switches are constructed in duplicate. Each generator
consists, primarily, of a Siemens armature, revolving between the poles of stationary
magnets. The armature is connected through intermediate gear with a fly-wheel, to
prolong its operations and continue the same after its driving devices have ceased their
action.
$
The intermediate driving gear embraces a spur wheel, mounted on and connected
by a ratchet or friction.clutch: to a shaft, said shaft being encircled by a strong spring,

page_text: one end of which is fixed to the shaft and the other to a stationary support, when thố
The outer end.
shaft is turned the spring constantly tends to bring it back to zero.
to zero.
of the shaft carries a depending arm, acted upon by a spring also tending to bring it
The arm is turned backward and the springs compressed by another arm,
on a rock-shaft. This rock-shaft extends to a point near the track rail, and is there
connected by a link, with a track lever, pivoted at one end to a stationary support and
lying parallel with the rail in position to be depressed by the car wheels passing
thereover. Through the intermediate parts the wheel causes one arm to force back
the other, and compress the springs, which in re-acting turn the shaft and spur wheel,
thereby setting the generator in motion. Conducting wires suitably connected; at
the generator in a manner familiar to every person skilled in the art, lead the current
therefrom.. Commonly that form of generator may be used which transmits over the
conductors successive impulses or.currents of alternate polarity.
Referring to the signal; two semaphoric arms are fixed rigidly to opposite ends of
a horizontal shaft, mounted in a suitable frame at the top of a post or other support.
This shaft has a crank-arm, connected by a link, to a second crank, on the driving
shaft. This driving shaft is connected by intermediate gear with a shaft carrying an
obliquely notched hub. The hub is encircled by a ring, and contains a series of
rollers, seated in the notches of the hub, these parts serving jointly as a friction clutch
through which the hub and its connections are turned in one direction as the outside
ring turns to and fro. The rings are connected by pitmen with a vibrating pivoted
electro-magnet forming part of the motor. This magnet vibrates under the influenco
of an alternating current, between the pole pieces of permanent magnets. The
operation of the motor causes the clutch, through the intermediate parts, to turn the
crank on the horizontal shaft always in the same direction, half a revolution at a time
the effect being to swing the signal from the "safety" position upward to that of
danger," and vice versa. The action of the current upon the motor is automatically
arrested as the signal reaches either extreme of its movement by the automatic
switch.
"
The contained switch consists of a non-conducting hub fixed upon its shaft, the
periphery of this hub being divided into two semi-circular eccentric portions covered
respectively with conducting strips, set out of line and out of contact at their adjacent
ends. Four conducting fingers are arranged to bear upon the conducting surfaces
of the switch, two upon each surface., Under this arrangement the switch at all
times couples the conducting fingers together in two-pairs, but as the switch revolves
a quarter of a revolution at a time it changes the connections, and thus automatically
makes, breaks, or diverts the currents. Suitable conducting wires are taken from
these fingers and coupled with the various portions and parts of the apparatus, in a
manner to give the described result.
In the modified apparatus for long trains the circuit-closing magnet switch is
introduced into its proper conductor.
In practice the current from the middle generator say, causes the operation of the
motor and lifts the signal to "danger," at the same time turning the switch. As the
signal reaches the "danger" position the switch assumes an altered position, where-
upon the current from the generator is diverted from the motor and pursues the
course back to the rear signal. In this manner the current from the middle
generator is caused to operate the distant rear motor and restore the rear signal to
safety."
68
In practice the signals should be arranged at such distance beyond the generators
which set them to "danger," that the engineer may observe their inovement or failure
to move in passing them.
While those details of construction and arrangement have been described which
are found in practice to be best adapted for general use, it is to be understood that
the details of the gonerator, track connection, signal motor and switch may be
variously modified within the range of mechanical skill, and that either of said
elements may be replaced in the system by any known equivalent.
;

page_text: My correspondents are aware that magneto-electric generators have been provided
with track-levers so called by which they were actuated or set for automatic action by
passing trains also that signals have been combined with weighted gear trains which
were unlatched and permitted to operate by electro magnets controlled from a distant
point also that signals have been variously controlled by battery currents and
currents from magneto-generators. The invention resides not in the individual
elements or members of the apparatus but in the combinations hereinbefore referred
to, and which will be more particularly specified in the Complete Specification and
claims attached thereto.
Dated this 5th day of N 1000

page_text: A communication from abroad by THE PENNSYLVANIA STEEL COMPANY, of Steelton,
Pennsylvania, United States of America.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
Patent Solicitors, 6, Lord Street, Liverpool, and G, Bank Street, Manchester, both in the
County of Lancaster, and 323, High Holborn, in the County of Middlesex Civil
Engineer, 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 :-
The invention consists in an automatic block signal system as a whole, and in an
improved signal instrument which is adapted for use not only in the block system,
but also in other places as will hereinafter appear.
The signal instrument embraces as its fundamental features a semaphoric or visual
signal, an electric motor, intermediate gearing through which the motor operates
the signal in a positive manner, and an automatic switch by which the current
through the motor is arrested when the signal reaches its limit of movement in either
direction.
In the accompanying drawings:-
Figure 1 is a diagrammatic view of this system of apparatus in connection with a
railway.
Figure 2 is a like view including supplemental devices to ensure the proper action
when very long trains are employed.
Figure 3 is a top plan view of the magneto generator and its track connections.
Figure 4 is a section of the same on the line y y.
Figure 5 is a side elevation of the signal proper with its motor, driving gear and
automatic switch.
Figure 6 is a section of the same on the line a æ.
Figure 7 is a view illustrating the manner in which the signal instrument may be
used in connection with the manually-operated magneto generator.
In Figure 1 is represented a railway track divided into imaginary lengths or
sections A A' etcetera, commonly known in the art as "blocks."
At each junction
of the adjacent blocks is placed a semaphoric or similar visual signal
B¹ B² etcetera,
of any suitable form adapted to be seen by engineers or others controlling the
trains. To the respective signals are connected by intermediate gearing, electric
motor's CCC etcetera, by means of which they are positively moved to each of
their required positions. The motors may be of any appropriate type known in the
art. Each motor is also geared to and operates an automatic rotary switch D D¹ etcetera,
controlling the course of the current, and determining which of the signals shall be
operated and the direction of the movement, as hereinafter recited in detail.
At the end of the respective blocks are located magneto-electric generators or
lynamo-electric generators E E' etcetera, each provided with suitable track connec-.
tions, commonly known in the art as "track-levers" of which there are many forms in

page_text: existence, through which the generator is actuated or set for automatic action by passing
trains so as to produce a prolonged current or succession of currents.
Each generator
is connected by suitable conductors with the motor of the adjacent signals through the
automatic switch of the latter, and from the switch of each signal, conductors are also
extended to the next signal to the rear at the opposite end of the block. The arrange-
ment, presently to be recited in detail, is such that the current from each generator is
applied to the motor of the adjacent signal to set the same at "danger," and also
applied, preferably at a later moment, to actuate the motor at the rear of the block to
set its signal to "safety."
26
The operation is as follows:-
Assume that the train moves to the left over the road, and that a train is upon the
block A, as shown in Figure 1. At this time the signal B at the end of the block in
rear of the train stands at "danger" to prevent another train from entering the block
at the same time, and, if the next section ahead is clear its signal B', will stand at
safety." As the train enters the block A', it sets generator E' in motion, and the
current from the latter is immediately applied through switch D' to motor ", which
turns the signal B' to the "danger "position. During this action the automatic
switch is turned, and when the signal reaches the "danger" position, the current is
diverted from the motor to the distant motor C which moves the rear signal B-to
safety, thus informing the following train that the first train has passed from
block. A to block A', and that the former is clear. This operation is repeated at the
end of each block, each train setting the danger signal as it enters a block,.and
setting the safety signal at the rear end of the block as it leaves the same at the
opposite end.
In certain cases where trains are very. long or the blocks very short, the front end
of the train acting upon the generator will set the signal at the rear of the block
at "safety," while the rear end of the train is still in dangerous proximity thereto. To
avoid this difficulty, supplemental devices are provided, illustrated in Figure 2,
which serve to open and keep open the circuit leading to the signal in rear of the
train until the rear end of the train has left that block or section. This effectually
prevents the signal at the rear end of the block from being set to " safety
" until
the train has passed from the opposite end of the block.
In this form of apparatus the blocks or sections of track are insulated from each
other; and the two rails at the rear, end of each section connected with each other
by a conductor a, through a battery a. At the opposite ends. the respective rails
are connected by conductors a² a³ with an electro-magnet a', which attracts an
armature a³, forming or operating a switch through which the current passes to
the rear signal. When the section is clear, that is to say, without trains upon it, the
circuit is completed through the battery, the two rails, and conductors a² a³ to the
armature a, which keeps the signal circuit closed at the magnet. When, however, a
train or any portion of a train stands upon the section A, the battery is short
circuited through the wheels and axles of the train from one rail to the other, so
that the magnet a' is discharged and the armature a retracted by springs aº, so
that the circuit to the rear signal is opened and kept open in such manner that
although the generator E may be set in action and the switch B' properly turned,
the rear signal B cannot be set to "safety" until the rear end of the train leaves
the section A, and allows the magnet a to again close the circuit. A like arrangement
is used in each block or section.
Having now described the general organisation and operation of the system, the
details of the generator, signal and switch will be described as far as may be necessary
for present purposes.
The generators, signals, and switches are constructed in duplicate. Each generator
consists, as shown in Figure 3, primarily of a Siemens armature, e, revolving between
the poles of stationary magnets e'. The armature is connected through intermediate
gear with a fly-wheel, e, to prolong its operations and continue the same after its
driving devices have ceased their action.

page_text: The intermediate driving gear train embraces a wheel e, connected by a friction
clutch to shaft et, encircled by a strong spring e, one end of which is fixed to a shaft
and the other to a stationary support. The end of the shaft carries a depending
arme (see Figure 4) acted upon by a spring e. The arin is turned backward
and the springs compressed by an arm on a rock shaft, e. This rock shaft
extends to a point near the track rail, and is there connected by a link e" with a
track lever e, pivoted at one end to a stationary support, and lying parallel with
the rail in position to be depressed by the car wheels passing thereover. Through
the intermediate parts, the wheel causes the arm to force back the arme, and
compress the springs, which in re-acting turn the shaft e and wheel e³, thereby
setting the generator in motion. Conducting wires e¹³ and et suitably connected at
the generator in a manner familiar to every person skilled in the art, lead the
current therefrom. Commonly, that form of generator may be used, which transmits
over the conductors successive impulses or currents of alternate polarity.
are
The signal is fully illustrated in Figures 5 and 6. Two seinaphoric arms
fixed rigidly to opposite ends of a horizontal shaft, mounted in a suitable frame.
at the top of a post or other support. The shaft has a crank-arm 62, connected by.
a link to a crank on a driving shaft 65. This shaft is connected by intermediate
gear with a shaft carrying a notched hub . The hub is encircled by a ring 7,
and contains a series of rollers 18, seated in the notches of the hub, these parts
serving jointly as a friction clutch through which the hub and its connections are
turned in one direction as the outside rings turn to and fro. The rings are connected
by pitmen, with the vibrating pivoted electro-magnet e forming part of the
motor. This magnet vibrates under the influence of an alternating current, between
pole pieces of permanent magnets ². The operation of the motor causes the
clutch, through the intermediate parts, to turn the crank always in the same
direction, half a revolution at a time; the effect being to swing the signal from
The action of
the "safety" position upward to that of "danger" and vice versa.
the current upon the motor is automatically arrested as the signal reaches either
extreme of its movement by the automatic switch.
The switch D consists of a non-conducting hub & fixed upon its shaft, the periphery
of this hub being divided into two semi-circular eccentric portions covered
respectively with conducting strips d¹ and d², set out of line and out of contact at
their adjacent ends. Four conducting fingers d³ ³ ³ do, are arranged to bear upon
Under this arrange-
the conducting surfaces of the switch, two upon each surface.
ment the switch at all times couples the conducting fingers together in two pairs,
but as the switch revolves a quarter of a revolution at a time, it changes the
connections in the manner shown in the several signals. Figures 1 and 2, the
fingers and d being coupled together at the same time that and d are coupled,
while on the other hand, d and d' are coupled at the time that and do are connected.
The conductor from the generator leads to finger de; finger ³ is connected by
wire d with the motor magnet from which a conducting wire d leads to wire d
extending to the motor magnet of the next signal. Finger d³ is connected by
wire do with finger d' of the next signal to the rear.
In the modified apparatus shown in Figure 2, the circuit-closing magnet switch a* a³
is introduced into the conductor d¹º.
In detail, the action of these parts is as follows:—
When the signal is at "safety" the switch stands in the position shown at D',
Figure 2. When the adjacent generator E' is operated, the current passes through e¹³, do,
switch surface d', finger d³, wire d', motor magnet c, wire d, and wire e back to the
generator. The generator current, therefore, causes the operation of the motor (", and
lifts the signal to "danger," at the same time turning the switch. As the signal reaches.
the "danger" position, the switch assumes a position similar to that of the switch in
signal B, whereupon the current from generator E' is diverted from the motor C",
and pursues the course indicated by the broken arrows. That is to say, from
generator E, through wire e¹³, finger do, switch surface d', finger d³, wire do, to the
finger d' of the rear signal B, thence through its surface, finger d³, the magnet

page_text: of motor C and wire d', wire el to the generator E'. In this manner the current
from generator E is caused to operate the distant motor C, and restore the
signal B to "safety."
In practice, the signals should be arranged at such distance beyond the generators
which set them to "danger," that the engineer may observe their movement or
failure to move in passing them.
While those details of construction and arrangement have been illustrated and
described which are found in practice to be best adapted for general use, it is to be
understood that the details of the generator, track connection, signal motor and
switch may be variously modified within the range of mechanical skill, and that
either of said elements may be replaced in the system by any known equivalent.
My correspondents are aware that magneto-electric generators have been provided
with track-levers so called, by which they were actuated or set for automatic action
by passing trains: also that signals have been combined with weighted gear trains
which were unlatched and permitted to operate by electro-magnets controlled from
a distant point: also that signals have been variously controlled by battery currents
and currents from magneto-generators, but the invention resides, not in the
individual elements or members of the apparatus, but in the combinations specified
in the claims.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, as communicated to
me by my foreign correspondents, I declare that what I claim is :-
1. An automatic block signal system embracing the signal instruments, the motors
applied to positively move the same, the generators and their track connections, and
the conductors and switches when said elements are combined for joint operation, in
substantially the manner herein described.
2. As a means of automatically setting a signal alternately to "danger" and to
"safety" by the action of moving trains, the combination substantially as described,
of a visual signal, an electric motor for operating the same, two widely separated
magneto-generators each provided with track connections to be actuated by passing
trains, conductors leading from the generators to the signal motor, and an automatic
switch connected with the signal and acting to connect the motor with the two
generator circuits alternately as the signal is changed from one position to another.
3. In a railway signal system the combination of two signals widely separated,
and each provided with an electric motor, a magneto-generator provided with track
connections whereby it may be driven from passing trains, conductors from the
generator to one of said signals, a conductor from said signal to the other, and an
automatic switch at the first signal for cutting out its own motor, and directing the
current to the motor of the second signal; whereby a moving train is enabled to set
a forward signal at "danger" and a rear signal at "safety."
4. In a block signal system a series of magneto-generators located at intervals along
the road and each provided with track levers to be operated by passing trains, a
corresponding series of visual signals, an electric motor geared to each signal to
positively move the same, and electrically connected with one of the generators,
electric conductors extending from each signal to the motor of the next signal to
the rear, and an automatic switch in each signal acting to direct the current of the
adjacent generator temporarily through the conductors to the motor of the rear
signal as described whereby an advancing train is enabled to set the adjacent
signals to "danger" and the signals in its rear to "safety."
""
5. In a block signal system in which the moving trains act to set the signals
behind them to "safety," the combination of a visual signal and an electric motor
to actuate the same, a distant magneto-generator in the direction toward which the
trains advance in leaving the signal, track connections for operating said generator,
electric connections between said generator and the signal motor, a voltaic cirenit
including an electro-magnetic switch between the generator and motor to interrupt
their connection, and also including an insulated track section: whereby the

page_text: presence of a train on the said track section will prevent the generator from
operating the signal.
6. The vibratory semaphore, its arm, the crank and pitman to move and hold the
same, the vibratory motor, and the intermediate clutch mechanism for imparting a
rotary motion from the motor to the crank, said parts being combined for joint
operation as described.
7. The vibratory semaphore, the gear train to move the same, the electric motor
for driving the gear train with a prolonged or continuing action,. and the rotary.
magneto-generator adapted to produce a prolonged or continuing current
succession of currents to operate the motor, said elements combined substantially
as described to impart a positive and gradual movement to the semaphore.
Dated this 20th day of December 1888.
or
WM. P. THOMPSON & Co
Agents for the Applicants.