Improvements in and relating to Apparatus for Signalling on Railways, and for Opening and Closing the Gates of Level Crossings and the like.
Year: 1890

page_text: Date of Application, 18th Nov., 1890-Accepted, 20th Dec., 1890
'LETE SP
ICATION.
Improvements in and relating to Apparatus for Signalling on
Railways, and for Opening and Closing the Gates of Level
Crossings and the like.
I, WILLIAM DART SHELDON, of 218 Washington Street, in the City of Providence,
County of Providence, State of Rhode Island, United States of America, Electrical
Engineer, do hereby declare the nature of my invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :-
My invention has reference to a new and useful improvement in train signals for
railroads, and I hereby declare that the following is a full, clear and exact description
of the same; reference being had to the accompanying drawings forming part of this
Specification.
The object of this invention is to control the signals, along the line of a railroad,
automatically by the passing train, and so construct the system that a train is signalled
at all times day or night by a signal in front of the train and a signal in its rear.
Another object of this invention is to light the road-bed in front of a train by
successively lighting electric lamps in advance of a moving train.
The invention consists in providing a number of electric switches, to be operated
by the passing of the train, to connect and disconnect the electric current with the
electric lamps.
The invention further consists in providing a number of electric switches, constructed
to be operated automatically by the passing train, by which the electric current is
connected with and disconnected from a series of electro-motors connected with and
operating a semaphore or other signal; and the invention further consists in connecting
any gates, along the line of the railroad, with electro-motors and automatic switches,
so that the passing of the train automatically closes and opens the gate, as will be more
fully set forth hereinafter.
To enable others skilled in the art to clearly understand the nature of my invention
and the manner in which the same is to be carried into effect and operated, I will
describe the automatic lighting first, and the signal system, as also the gate-operating
devices, after.
On each side of the road, at such distances apart as experience and the situation of
the road may require, electric lamps are placed; these are connected with one of the
wires forming an electric circuit, which circuit is connected with a generator. Thus
along a railroad the wires of the circuit may be connected with the dynamos of the
electric plants of the towns or stations on or near the road or with any other source of
electric energy.
All the lamps on each circuit are connected with the positive conductor-wire, while
the negative conductor-wire is, at each lamp, connected with a switch normally open,
from the switch the wire extends to a lamp, so that by closing the switch the circuit
for one lamp will be closed and the lamp lighted. An electric lamp is thus auto-
matically lighted at any desired point in front of the train and is extinguished after
the train hus passed the lamp. A train may thus continuously signal its approach at
night and light up the road-bed in advance.
Figure 1 is a perspective view of a double-track railroad showing the electric-lamps,
the semaphore-signals, and gates at the railroad crossings as operated by the passing
of a train.
Figure 2 is a plan view showing the connections of the circuit wires with the
switches and the lamps for lighting the road-bed.
Figure 3 is a plan view showing a railroad car on which a storage battery or other
source of electric energy is carried and connected by means of trolleys or contact-arms
with the two conductors of a circuit connected at each end with a lamp, so that a lamp

page_text: my invention.
Figure 4 is a vertical cross section,
Figure 5 a vertical longitudinal section, and
Figure 6 a horizontal section of the switch-box and operating arm placed parallel
with the rail so that the wheels of a passing train will automatically operate the
same.
Figure 7 is a view, partly in section, of the contact-arm or trolley used in
connection with the modified system for lighting shown in Figure 3.
Figure 8 is a sectional view of my improved automatic signal showing the switch
operated by the passing train; the electro-motor, the semaphore, operating mechanism
and the conductor-wires. The post on which the signal apparatus is supported is
shown as partly broken away.
Figure 9 is a plan view, and
Figure 10 is a sectional view of the signal-operating mechanism.
Figure 11 is a view of a modified form of a signal-operating mechanism, provided
with an electric-lamp, showing the automatic switch for connecting and disconnecting
the electric-lamp.
Figure 12 is a view of a modified form of signal showing the electric-lamp.
Figure 13 is an enlarged view of the automatic switch by which the lamp is
connected and disconnected.
Figure 14 is a skeleton view showing the connections between the main circuit
wires, the switches and the signal or gate-operating mechanism.
Figure 15 is a sectional view of the automatic switch showing the conductor-wires
as carried through a tube or pipe.
Figure 16 is a vertical sectional view of the automatic gate-hox showing the
mechanism for operating the gate-arms.
Figure 17 is a sectional view of the gate-operating mechanism at right angle to the
view shown in Figure 16.
Similar letters and numbers of reference indicate corresponding parts.
Referring to Figure 2 the letter a indicates the first wheel of a railroad train
moving in the direction indicated by the arrow, bis the first switch. (The con-
struction of the switches may be varied to suit the conditions under which they are
to be operated. The essential elements of each switch are an arm or spring actuated
by the passing train, a contact-lever operated by the arm to close the circuit and
provided with an armature, and an electro-magnet the wire of which is connected
with one arm of the main circuit and with the contact point of the next or some other
switch. The particular construction of the different switches shown in the drawings
will be more fully described hereinafter.) c is the second switch, d indicates the
source of electric energy, e one arm of the electric circuit, preferably the positive,
and the other arm or negative conductor, g and g' the electric lamps. The solid line
arrows indicate the connection of the conductor e with the lamp g and from the
lamp g to the contact-arm 19 of the switch 6. This switch is shown in its normal
condition as open, when the wheel depresses now the arm 14 and by means of the
connecting arm, against the resistance of the coiled spring, depresses the contact-
arm 19 to close the circuit, contact is made with the point 26 which is connected_by
the conductor with the arm f of the circuit, as is shown by the solid line arrow.
lamp g is now in the circuit and lighted. The wheel a, of the train, traversing the
distance between the switch band the switch c, depresses the arm 14 and contact-
arni 19 closing the circuit in switch e; the direction of the electric current in this
condition of the switch c is indicated by the broken line arrows.
C
The conductor e is
connected with the lamp g' and extends from the lamp to the contact-arm 19, the
current passes through the same to the contact-point 26 of the switch c and from this
to one end of the wire of the spool of the electro magnet 24 in the switch b, the other
end of the wire of the spool is connected by a conductor wire with the conductor of
the main circuit. The lamp g' is therefore in the closed circuit and lighted. The
electric energy, passing through the spool of the electro magnet 24 in the switch b,
The

page_text: raises the contact-arm 19 and thus, by breaking the circuit indicated by the solid-line
arrows, extinguishes the light. The arrows having a circle on the shaft indicate
the connection of the conductor from the switch in advance of the switch c with
the electro-magnet 24 of switch and with the conductor of the main circuit.
It will, therefore, be seen that ench switch, when operated by a passing train, closes
the circuit connected with one lamp and opens the circuit connected with another
lamp, so that each switch lights one lanp and extinguishes another.
The electric lighting of the road-bed may be accomplished by carrying a dynamo,
a storage battery, or any other convenient source of electric energy on the train, as
is shown in Figure 3. The conductor wires e and are shown connected with the
lamp g. The wires are placed on poles along the line of the road, the source of
electric energy on the car may now be connected with the wires e and by the
trolleys or contact-arms and instantly the lamp in advance of the train will be
lighted. The lamp will, in case of an accident, or delay, light the road-bed and act
as a signal to approaching, trains.
By arranging a succession of these circuits each provided with a lamp and using
such a trolley as is shown in Figure 7, the train carrying the source of electric
energy d will, as long as contact is maintained, have a lamp lighted in front of
the train.
The switch, shown in Figures 4, 5 and 6, is a modified form of the switch shown in
Figure 2 and differs from the same as also from the switch shown in Figures 8 and 15
by having the contact-arm placed so as to move horizontally instead of vertically;
the arm 14 is provided with a beveled cam by which the contact-arm 19 is moved
laterally to close the circuit, while the electro-magnet, when energized, will draw the
contact-arm away from the contact point or clip, as is shown in Figures 4 and 6.
The day signals I operate by the mechanism shown in Figures 8, 9, 10 and 11
through a switch, clearly shown in Figures 8, 14 and 15, the operation of which is
as follows:-On one side of the rail 13 the arm 14 consisting of a stiff curved
spring hinged at one end and bearing against the abutment 16, the other end
resting on the plate 17, so that on the passing of a train the wheels will depress the
upper curved portion of the arm, the free end sliding on the plate 17. The curved-
arm 14 is shown as placed on the outside of the track for the sole reason that the
connections can be more clearly shown with the oporating switch. In practice the
arm 14 may be placed on either side of the track or between the rails.
The switch proper, as shown in Figures 8, 14 and 15, consists of the lever 19
pivoted on the standard 20. The projecting end of the lever is connected with a
bracket extending from the standard 20 by the spring 21 holding the lover in the
raised position, the short end of the lever resting on the screw 22 forming an
adjustable stop for the lever. The lever 19 is provided with the armature 23, the
electro-magnet 4 is secured to the base 25, the spring contact-points 26 are mounted
on the insulated support 27, the conductor-wire 28 is connected with the spring
contact-points 26 and forms one arm of an electric circuit, the conductor-wire 29
forming the other arm of the circuit, is connected with one end of the wire of the
spool of the electro-magnet 24 and from the other end of the wire extends to the
base 25, the current passing through the base 25, the standard 20 and lever 19.
If now a passing train depresses the arm 14 the lever 19 is forced between the
spring contacts 26 making a wiping frictional contact by which the conductor-wire 28
of one arm of the circuit is connected through the contact-points 26, the lever 19,
standard 20, electro-magnet 24, and base 25 with the conductor-wire 29, the current
passing through the wire of the spool energizes the magnet 24 and holds the lever 19
by means of the armature 23 in this position so long as the circuit remains closed.
Mounted on the post 34 is the practically water-tight case 35 and in the same is
secured the electro-motor 36. The end of the driving shaft of the motor is provided
with the pinion 37 which gears with the gear-wheel 38 secured to the shaft 39,
which shaft is supported in suitable hearings and is provided with the worm 40 which
drives the worm-gear 41 sccured to the shaft 42, which shaft is supported in suitable
bearings. One end of the shaft 42 extends through the case and has secured to it,

page_text: outside the case, the arm or semaphore 43. The worm-gear 41 is provided with the
pin 44 projecting from one side of the worm-gear and the pin 45 projecting from the
opposite side of the worm-gear 41. The wire 28, from one of the switches operated
by the passing train, connects with the post or contact-point 46, and the other wire 28,
from another switch operated by a passing train, connects with the post or contact
point 47. The spring arms 48 and 49 extend from the plate 50 over the contact-
points 46, 47, on each side of the worm-gear 41, so that when the said worn-gear is
turned the pins 44 and 45 will at certain predetermined intervals raise the spring
arms one at each time off from the contact-points 46, 47, and break the circuit.
In the normal condition both of the spring arms 48, 49, are in contact with the
posts 46, 47, and the plate 50 is connected with the electro-motor 36 by the
conductor-wire 51.
Considering now the operation of the devices as shown in Figure 14, in which the
electro-motor is connected with two switches constructed to be operated at points on
either side of the signal-oporating mechanism and having the details of the mechanism
shown in Figures 8, 9 and 10 in view, it will be seen that a train passing over the
first switch will close the circuit by connecting the branch conductor-wire 29 con-
nected with the arm 32 of the circuit through the spool of the magnet 24, the base 25,
the standard 20, the lever 19, and contact-springs 26, with the conductor-wire 28, and
by the same, through the post 47, spring-arm 49, and conductor-wire 51, with the
electro-motor 36, which is connected by the branch conductor-wire 31 with the other
arm of the circuit. The electric energy will now operate the notor 36, which, when
placed into the circuit, will revolve and always in the same direction, namely, to the
right. The mechanism will turn the worm-gear 41 and with it the semaphore 43 on
the outer end of the shaft from the vertical position shown in Figure 8 in solid lines
to the horizontal position shown in broken lines, when the pin 15, which is placed at
right angle to the centre of the worm-gear, and the pin 44 will raise the spring-arm 49
off from the contact-post 47 and break the circuit, stopping the motor, demagnetizing
the magnet 24 of the first switch and permitting the spring 21 to raise the lever to
the normal position shown in Figure 8. When now the train reaches the next
switch the arm 14 will be depressed, the lovor 19 will enter between the contact
points 26, the conductor-wire 29 will be connected through the switch with the
conductor-wire 28 and this through the post 46, the spring-arm 48 and wire 51, will
place the electro-motor 36 in the circuit through the branch conductor-wire 31. The
electro-motor will operate, through the mechanism, the arm or semaphore 13 by
turning the same through three-quarters of a circle until the semaphore is in the
vertical position, as shown in solid lines in Figure 8. In this position the pin 44 on
the worm-gear will raise the spring-arm 48 off from the post 46 and, by thus breaking
the circuit, will stop the electro-motor and release the switch. Each switch is con-
nected with two signal-operating devices by the conductor-wires 28 connecting the
contact-springs 26 with the post 46 in one direction, and with the post 47 of another
signal-operating device in the opposite direction. In practice the switches are placed
near each signal-post, but the switch near the post is not connected with that post, but
is connected with the signal on the next post in advance of the switch and with the
signal on the next post in the opposite direction, so that a passing train will on passing
over the arm 14 of any switch connect the circuit with the electro motor in advance
of this switch on the further end of the section or block and thus cause the block
signal to be displayed at this end, while the same switch will also close the circuit
and cause the electro-motor on the rear end of the section over which the train has
just passed to move the block signal to the open or safe signal.
In place of the arm 43 moving in a vertical plane, the signal or semaphore shown
in Figures 11 and 12 turning in a vertical plane may be used, operated by the same
mechanism as is shown in Figures 8, 9 and 10, with the difference that the shaft of
the worm-gear on the outer end of which the signal-arm or semaphore is secured is
placed in a vertical instead of a horizontal position. The electro-motor may be placed
under the signal-operating mechanism for operating either of the two forms of signals,
the same as is shown in Figure 11 for operating the signal turning on a horizontal

page_text: plane, in which a well-known form of signal consisting of a disk and the arms 53
placed at right angle to each other are supported on the end of the shaft 42 above the
case 35. As this signal is designed to turn one-fourth of a circle at each operation,
the worm-wheel is provided with two pins 44 for raising the spring-arm 48, and two
pins 45 on the opposite face of the worm-wheel for raising the spring-arm 49,-these
pins are placed so that a line from one to the other of the two pins 44 will be at right
angle to a line drawn from one to the other of the two pins 45, and the electro-motor
will turn the worm-wheel at each time one-quarter only.
This signal may be surmounted by the lantern 54 in which the lamp 55 is placed;
the lamp is connected with both arms of the electric circuit by the conductor-wires 58
and 59 and cut in and out by means of the cam 57 placed on the shaft 42 and rotating
with the same.
Railroad gates may be operated to close on the approach of a train and open after
the train has passed the gate by the electro-motor connected with a crank secured to
the gate-arm and the intermediate mechanism shown in Figures 8. 9, 10 and 11. The
arrangement of the electro-motor and the operating-mechanism is clearly shown in
Figures 16 and 17; as the gate-arms are swung to raise and lower the same through
an are not exceeding one-quarter of a circle, the shaft 42 of the worm-gear 41 is
provided at one end with the crank 64 connected by the link 65 with the crank 66
secured to the shaft 67 on the projecting ends of which the gate-arms are
supported.
When a train approaches the crossing it will pass over the arm 14 of the switch on
the side of the gate from which the train is advancing and close the circuit between
the conductors 28 and 29. Referring now to Figure 14 of the drawings, it will be
seen that as the electro-motor 36 is connected by means of the conductor 31 to the
aru 33 of the circuit and the conductor 29 with the arın 32 of the circuit, the inter-
mediate connection by the conductor-wire 28 with the operating mechanism and this
by the wire 51 with the electro-motor forms a closed circuit. The electro-motor will
now be started an I will continue to run until the worm-gear 41 has made one-half of
a revolution when one of the pins 44 or 45 will raise the spring-arm off from its
corresponding contact-point and stop the motor. The first operation will bring the
crank 64 into the position opposite the position shown in Figures 16 and 17 and will
close the gate. When now the train passes over the switch placed beyond the gate
the next switch will close the circuit again, start the electro-motor and turn the worm-
gear, through the intermediate mechanism, through one-half of a circle returning the
crank 64 and, by means of the link 65 and crank 66, the gate-arms into the raised
position shown in the drawings, when the motor is automatically stopped by one of the
pins on the worn-gear raising the spring-arm off from the corresponding contact
point and breaking the circuit.
As this class of railroad-gates are connected by suitable mechanism, such as the
sprocket-wheel 68 placed on the shafts supporting and operating the gate-arms,
connected with the endless chains 69 extending from the sprocket wheels of one of
the gates to the sprocket wheel or wheels of one or more other gates, by operating
one of the so-connected gates all the other gates will also be operated simultaneously
with the first.
->
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 :-
Claim 1. The combination with the track of a railroad and the two conductor-wires
of an electric circuit connected with a dynamo, of a series of electric lamps, one pole
of each of which is connected with one of the conductor-wires, the other pole of each
lamp being connected by a wire with a circuit-closing device, a conductor-wire
connecting the circuit-closing device with the other conductor-wire of the circuit, and
operative connections between two circnit-closers, whereby when one circuit-closer is
automatically actuated by the passage of a train its lamp is lighted, and the other
circuit is opened and its lamp extinguished.

page_text: 2. The combination with the track of a railroad and the two conductor-wires of an
electric circuit connected with a dynamo, of a series of electric lamps, one pole of
each of which is connected with one of the conductor-wires, the other pole of each
lamp being connected by a wire with a circuit-closing device, a conductor-wire
connecting the circuit-closing device with the other conductor-wire of the circuit, and
a wire operatively connecting two of the circuit-closing devices, all being arranged so
as to light a lamp in advance of a train and extinguish a lamp in the rear of the train,
automatically, as described.
3. The combination with a device for closing an electric circuit, a railroad track,
and an electric circuit connected with a dynamo, of a series of electric lamps connected
with one arm of the circuit, conductor-wires connecting each lamp with a circuit-
closing device, and an electro-magnet in each circuit-closing dovice connected by a
conductor-wire with the other arm of the main circuit and by a wire with another
circuit-closing device, all being arranged so as to light a lamp in advance of the train
and extinguish a lamp in the rear of the train, automatically, by the passing train, as
described.
4. In a railroad signal, the combination with the main-circuit conductors, a fixed
source of electrical energy, an electro-motor and an electric light in a circuit con-
trolled by the motor connected with one of the main-circuit conductors, of a switch
automatically actuated by means independent of the source of energy to make and
break the circuit between the motor and the source of energy, a semaphore and
operating mechanism therefor intermediate the semaphore and the electro-motor, a
second switch in the circuit actuated by the movement of the semaphore to cut out
the motor, and the connections intermediate the switch and the electro-motor, the
whole forming a complete metallic circuit whereby when the switch is actuated the
motor is started and stopped.
5. The combination with a railroad and a switch mechanically actuated by the
passage of a train to make and break the circuit through a motor, of an electric-motor,
an electric light in a circuit controlled by the motor, a stationary and constantly
charged source of electrical energy, mechanism for operating a signal by the motor,
a second switch in the circuit actuated by the signal to cut out the motor, and
connections between the main circuit, the motor and the switch, the whole forming a
complete metallic circuit, constructed to operate the signal and lights at a distance
from the switch, as described.
6. A railroad block signal, consisting of signals located at the end of each section
or block, a stationary and permanently charged source of electrical energy, electric
lights, electric-motors, mechanism connecting the motors with the signals, switches
located near the end of each section or block, and connections between the switches,
the motors and the electric-circuit conductors, all arranged so as to connect the motors
with the circuit and operate the signal and light in advance of and in the rear of a
passing train, as described.
7. The combination with a semaphore signal, a stationary and constantly charge:l
source of electrical energy, an electric-motor, mechanism for operating the semaphore
and automatically stopping the motor when the semaphore has moved to the desired
position, and a railroad, of two switches placed one on each side and at any desired
distance from the signal, each constructed to be operated automatically by a passing
train, and the connecting conductor-wires between the switches the motor and the
main-circuit, and the connecting wire between the switches, all arranged so as to start
the motor and operate the signal in advance of the passing train by one of the
switches and after passing the signal start the motor and operate the signal by tho
other switch, automatically, as described.
8. The combination with a semaphore signal, an electro-motor and operating
mechanism intermediate between the motor and the signal, as described, of an
electric lamp, a switch operated by the motor, conductor wires connecting the motor
and lamp with the main circuit, and a switch or switches for closing the circuit und
starting the motor, as described.
9. The berein described system of automatic railroad signals, the same consisting of

page_text: a series of semaphore signals placed at intervals along a railroad, a series of electric
lights, electro-uiotors connected by mechanism with the semaphores, said mechanism
consisting of a circuit-breaker to automatically stop the motor when the semaphore is
placed in the predetermined position, switches placed near each semaphore signal
connected with two signal-operating motors in opposite directions, and a main circuit
connectel with a stationary and constantly charged source of electric energy with the
motor and the switches, constructed to successively start each motor and display a
semaphore in advance of the moving train and drop a semaphore in the rear of the
train, and start the motor at the rear end of the section or block when the train leaves
the section or block to operate the signal and to light and extinguish the electric
lights, as described.
10. A railroad signal system, consisting of semaphores, a stationary and constantly
charged source of electric energy, electric lamps, and electro-motors for operating the
semaphores, and lamp cut-outs placed at intervals along a railroad connected with
switches operated automatically and mechanically by the passing train and with a
main circuit constructed to display a semaphore, and an electric light at each end of
each section or block occupied by the train, as described.
11. The combination with a railroad-gate and mechanism for opening and closing
the gate, an electro-motor connected with the mechanism and provided with two
contact points and two contact-arms operated automatically, of a switch placed at a
distance from the gate constructed to close a circuit by the passing train and start the
electro-motor to close the gate, and a switch placed at a distance beyond the gate and
operated by the train to close a circuit and start the electro-motor to open the gate, as
described.
12. The combination with a railroad track and a railroad-gate, of a bed-plate, gear-
mechanism for operating the gate secured to one side of the bed-plate, an electro-motor
for actuating the gear-mechanism secured to the other side of the bed-plate in line
with the gear-mechanism, an enclosing post within which the bed-plate is suspended
and suitable electrical connections whereby on the passage of a train the motor is
caused to operate the gate, as described.
13. The combination with a railroad track and a railroad-gate, of a post, a bed-
plate supported by brackets within the post, gear-mechanism for operating the gate
secured to one side of the bed-plate, an electro-motor for actuating the gear-mechanism
secured to the other side of the bed-plate in line with the gear-mechanism, circuit-
breakers secured to said bed-plate and operated by the motor, circuit-closers operated
by the passing train to close and open the gate automatically, and suitable electrical
connections, as described.
14. The combination with a gate having connections by which other gates are
operated, of an electro-motor connected by mechanism, substantially as described, with
the gate-operating mechanism, two or more switches operated automatically to close
the circuit with the motor by the passage of a train by one of the switches, two
automatic circuit-breakers operated by the motor and connections between the motor,
the switches and the main circuit constructed to close the gates on both sides of the
track on the approach of a train and open the same, after the train has passed the
gates, automatically, as described.
11: 30
1800
WILLIAM DART SHELDON.
Signed in presence of :-
JOSEPH A. MILLER, Junr.,
Providence, R.I., Ú.S.A.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.