Improvements in Electric Railway Signalling Systems.
Year: 1888

page_text: Improvements in Electric Railway Signalling Systems.
I JOSEPH IRWIN residing at 1808, Topeka Avenue, in the City of Topeka, County
of Shawnee, and State of Kansas, in the United States of America, Architect, 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:-
My invention relates to an improvement in electric railroad signalling systems and
it consists in the peculiar construction and combination of devices that will be more
fully set forth hereinafter and particularly pointed out in the claims.
The object of my invention is to provide an electric apparatus whereby a moving
train will transmit signals back to the starting station as it reaches each intermediate
station to indicate its position on the road and whereby the train will also transmit
signals ahead of it from station to station as it advances and thereby prevent
collisions.
In the accompanying drawings―
Fig. 1 is a diagram of an electric railroad signalling system embodying my
improvements.
Fig. 2 is a detailed perspective view of one of the intermediate station
indicators.
Fig. 3 is a vertical transverse sectional view taken on the line x x of Fig. 1.
Fig. 4 is a top plan view.
Fig. 5 is a detailed perspective view of one of the terminal station indicators.
Fig. 6 is a longitudinal section of the car.
Fig. 7 is a detail view of the post D showing the switch K.
A represents a railroad track. B, C, represent the terminal stations at opposite ends
of the track and, 1, 2, 3, 4 represent intermediate stations at suitable regular distances
apart along the railway:
Near each intermediate station is a vertical, post D having a horizontal arm E at its
upper end which extends over the track at a suitable height therefrom. Between the

page_text: posts are wire supporting poles F which are similar to the ordinary telegraphi
poles.
At each terminal station is an indicator G, the construction of which is as
follows:-
H represents an indicating disk or dial which has numbers from one up on its face
according to the number of intermediate stations on the track. In the present instance
there being four of such intermediate stations there are four numbers on the face of
the dial. I represents an arbor or shaft which is journaled in bearings in the centre
of the dial and is provided with an indicating hand or pointer K that is adapted to
sweep over the dial. To the said shaft is also attached a ratchet wheel L having as
many teeth as there are numbers on the dial. Formed with the said ratchet wheel (or
formed separately therefrom and secured to the shaft as may be preferred) is a friction
disk M.
N represents a retarding or brake spring which bears against the disk and is adapted
to prevent the shaft from turning idly in its bearings. O represents an electro-magnet
which is adapted to attract an armature P that is provided near its free end with a
spring actuated pawl R which engages the ratchet wheel. The movement of the
armature is regulated by adjusting stop screws S so that when the armature is attracted
by the magnet, the pawl by being in engagement with one tooth of the ratchet wheel
will turn the latter and consequently the shaft and the hand or pointer a distance equal
to the space betwcen two of the numbers on the disk. T represents a retracting spring
with which the armature is provided and the office of which is to return the armature
to its initial position when the magnet is demagnetized. U represents the main line
wire which extends from one terminal station to the other. The ends of the said wire
are connected to the coils of the electro-magnets O and from the other ends of the
said coils extend ground wires V which have an earth connection. The wire U is
attached to the arms E of posts D at the intermediate stations. At each intermediate
station is an indicator X which is constructed as follows:-
16
Y represents a disk having two points thereon at a suitable distance apart marked
safety" and "danger" respectively.
At the centre of the disk is a rock shaft Z having a hand or pointer A¹ adapted to
play between the safety and danger points on the disk. An armature B¹ is secured
to the rock shaft and projects therefrom and is adapted to be attracted by an electro
magnet C¹.
represents adjusting stop screws the function of which is to limit the movement
of the armature and El represents a spring brake which presses against a friction disk
on the rock shaft and thereby prevents the rock shaft from turning idly and moving
the hand or pointer.
al
The electro-magnet at station 1 is connected to the electro-magnet at station 3 by
wire F having ground wires G₁ and the electro-magnet at station 2 is connected to
the electro-magnet at station by a wire H¹ having ground wires l' each intermediate
indicator being thereby connected in circuit with the indicator which is two stations
in advance of it, or in other words, the alternate intermediate indicators are connected
in circuit together.
Each indicator 1 and 3 has a switch K adapted to short circuit the wire F to the
ground and each indicator 2 and 4 has a similar switch L' adapted to short circuit the
wire H to the ground and these local signal or intermediate wires F¹ and H' are also
attached to the arms E of posts 1).
In one car M' of each train which runs over the road are located two batteries N¹
and 01 each of which has one of its poles connected to one of the axles of the car and
thereby connects it through the car wheels and the track to the ground. In the roof
of the car M on one side thereof are two spring contact plates P1 and R₁ which are
connected to the remaining poles of the batteries N' and O' respectively and are
adapted to come in contact with the wires on the arms E as the car passes under
them.
Included in the wire which connects the poles of the battery 'N' to its spring plate P¹
is the electro magnet of an annunciator or electric gong S¹. The said gong is here

page_text: shown arranged in the car but the same should preferably be located in the engineer's
cab on the locomotive.
In order to enable the indicators to be visible at night I propose to make the disks
or dials thereof transparent or semi-transparent and place lights behind the same so as
to illuminate the figures or signals thereon.
The operation of my invention is as follows:-
When a train running in the direction indicated by the arrow in Fig. 1 leaves the
station B at one end of the line the operators at the intermediate stations 1, 2 move
the switches at said stations so as to break the connection between the local signal
lines and the ground and the operators at the stations 3 and 4 move their switches so
as to make connection between their ends of the local signal lines and the
ground.
The hand of the indicator at station B will point to 1 and the hands of the
indicators at the intermediate stations will be turned and caused to point to
safety."
"
This arrangement of the switches and indicators is shown in Fig. 1.
.
When the train reaches the first intermediate station, the plate P₁ of battery N¹ will
come in contact with the wires U and thereby connect the said wire to the ground
when a current of electricity will be caused to flow momentarily in short circuit
through the wire U to the station B influence the electro-magnet there so as to cause
it to attract the armature and thereby turn the shaft of the indicator to make the hand
or pointer point to 1 on the dial and thereby indicate to the train despatcher that the
train has reached station No. 1. At the same instant the plate R comes in contact
with the local signal wire F¹ and connects the same to the earth and causes a current
from the battery to flow momentarily through the wire F, and thereby cause the
electro-maguets in the indicators 1 and 3 to attract their armatures and thereby move
the hands in said indicators to the "danger" point thus sending the Signal that the
train is coming two blocks or stations ahead. The brake springs hereinbefore
described keep the hands pointing to danger and prevent them from swinging idly
therefrom.
When the train reaches station 2, the plate R¹ comes momentarily in contact with
the wire H and the current from battery O' charges the electro-magnets at stations 2
and 4 and thereby causes the hands of their indicators to move to danger" thereby
again telegraphing two blocks or stations ahead of the train as before. The plate P
comes in contact with wire U as the train passes each station thereby causing the
hand of the indicator at station B to move from figure to figure. on the dial and con-
sequently indicate by pointing to its appropriate number when the train passes cach
station and consequently keeps the train despatcher acquainted with the position of
the train at all times during the entire trip and enables him to keep a record of
the same.
As the train passes each intermediate station, the current from the battery 0¹ at
the same instant that it moves the hands of the alternate indicators, also sounds the
gong thereby assuring the engineer that the switches are properly set and the signalling
apparatus is in order but in the event that the operator at one of the stations should
neglect to set his switch properly so as to disarrange the signalling apparatus, the
local signal circuit would not be completed when the train reached that station and
hence the gong would not be sounded and the engineer would know at once that the
signals were not in working order.
When the train is running from C to B the switches will be set in the reverse
positions from those herein before described and shown in Fig. 1 as will be readily
understood. At a suitable interval of time after the train passes each station the
operator stationed there will move back the hand of his indicator to its initial "safety"
point.
I do not desire to limit myself to the precise construction and arrangement of
devices herein before described as it is evident that modifications may be made therein
without departing from the spirit of my invention.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is :-
1. In electric railway signalling, systems, the combination of the intermediate
indicators connected together alternately in local circuit and the moving car having
the battery and devices to include the same momentarily with the indicator circuits
for the purpose set forth substantially as described.
2. In electric railway signalling systems, the combination of the line having the
indicating device at the starting station included in its circuit, the intermediate
indicators connected together alternately in local open circuit, the switches to open
either end of each local signal circuit and the moving car having the batteries and
devices to include the same momentarily with the line and local circuits and thereby
operate each alternate pair of intermediate indicators in succession and also operate
the indicator at the starting station as the car passes each intermediate indicator
substantially as described.
3. In electric railway signalling systems, the combination of the constantly closed
main line, the electric magnetically operated indicators included in circuit therewith
at the starting and terminal stations, the local signal circuits having the intermediate
electric magnetically operated indicators, the ground or return wires and the switches
to open either end of each local circuit and the moving car having the main and local
batteries and devices to connect the poles thereof momentarily with the main and local
lines respectively at intermediate stations for the purpose set forth, substantially as
described.
4. In clectric railway signals the local signal circuits having the intermediate
indicators, the return or ground wires and the switches to open either end of each
local signal circuit, in combination with the moving car having the battery and devices
to connect the same with the local signal circuits successively, substantially as
described.
BERNHARD DUKES,
226, High Holborn, London, W.C.,
Agent for the Applicant.