Improvements in. Electrical Signalling Apparatus for Railways.
Year: 1886

page_text: Improvements in. Electrical Signalling Apparatus for Railways.
I, CHRISTOFFER RETZIUS-EKWALL, of Linköping in the County of Östergötland,
in the Kingdom of Sweden, Engineer do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:—
This invention relates to electric apparatus for preventing collisions between
railway trains.
The chief object of the said invention is to enable an engine-driver, independently
of the station officials, to ascertain, by means of certain signals, whether a train is
in motion on the part of the line before him either in the same or in the opposite
direction to that in which his own train is travelling.
s
This is effected by arranging at every station beyond its most distant points or
switches in either direction two signal bells or hands (a pair for each switch)
which, by means of conducting wires, are connected with apparatus hereinafter
described at the stations, and so disposed that, when a train is passing a certain
point outside the station they are caused to operate thus bringing a bell at the
starting station and two bells or hands at the next station into action. If then
a train is departing from the latter station in the direction of the former, its driver
will be advised by the signal bells or by the motion of the hands at the most
distant switch from the station, that a train has already departed from the next
station and is advancing against him. If at the station from which he is departing,
only one bell (or hand) is in motion, this signifies that a train is before him
running in the same direction and has not yet reached the station, wherefore the
driver must advance with caution. If both the bells at the station, from which
the train is departing are silent, or the hands, if such are used, are in their normal
position, the track is clear.
From the above description it will be understood that the principal responsibility
will thus rest upon the engine driver, and not, as heretofore upon the station
officials.
In the accompanying drawing
Figure 1 is a side elevation of the improved apparatus mounted at two stations,
and
Figure 2 is a plan of the same.
Figure 3 is a rear elevation of one set of apparatus, and
Figure 4 is a front view of the same.

page_text: secured to the lower leg of a fork G carried on a shaft H of ebonite turning in the
bearings C. The hind part of this fork is bent at a right angle and provided with
an armature I, below which an electro-magnet K is placed. To the standard D
the spring L is secured, which is provided with an armature M under which a
smaller electro-magnet N is placed. The standard D¹ is, at the top, divided in two
branches, insulated one from another and each provided in its upper part with a
point of contact. To these two points of contact correspond two springs of platina
secured to the lower side of the spring L. and having for their object to close the
circuit from the local battery.
On the shaft H are two metallic rings O, P supporting respectively on their
lower sides a spring projecting downwards and having for their object according to
the position of the fork G to make contact with two and two of the attachment-
screws a¹ a² a³ a secured on each side of the shaft. The screw a' by means of a
circuit passing through a galvanometer placed in the front of the magnet E is
connected with a pole of the said electro-magnet and the screw a¹ with one pole of
the electromagnet N.
Qis a bent lever provided with an upper and a lower contact, against which the
legs of the fork G bear, during the working of the apparatus. For effecting a sure
contact the lower leg of the fork and the top of the lever Q are provided with thin
springs of platina R R¹.
In order to moderate the speed of fall of the fork G, its upper leg G¹ is
, prolonged and terminates with a kind of bowl c under which a bag y of india-
rubber, provided with a fine opening is secured on the bent lever Q. When the
fork is falling against the upper contact of the lever Q, the air contained in the
bag y is pressed out slowly, whereby the falling of the fork does not take place too
rapidly. During the ascending of the fork the bag y is again filled with air drawn
in through the said opening.
In front of the electro-magnet E are placed two galvanometers. On the ebonite
platform 'A are also secured a number of attachment screws, through which the
circuit between the batteries, the signal bells or the hands and the different parts
of the apparatus is established. The attachment screw 1 is, by means of a
conducting wire in connection with one pole of a battery and with one pole of the
electro-magnet K, the other pole of which is by means of another conducting wire
connected with the attachment screw 2, which, in its turn, is connected with a
contact (Figure 5) applied to the rail track and hereinafter described. The
attachment screw 3 is connected with a wire conducting to the corresponding
screw of the apparatus placed at the next station and with the metallic ring Ŏ
secured on the ebonite shaft H. The attachment screw 4 is connected with the
earth and with the upper leg G¹ of the fork G; which leg, by means of inter-
mediate ebonite, is insulated from the other part of the fork. The attachment
screw 5 is connected with one pole of a battery and with the lower leg G₁ of the
fork G. The attachment screw 6 is connected with the outermost of the two
signal balls arranged at the most distant switch and with the attachment screw a³
and one arm of the standard D¹. The attachment screw 7 is connected with the
bell situated next to the station and with the second of the insulated arms of the
standard D. The attachment screw 8 is connected with a local battery, with
metallic ring P secured on the ebouite, shaft H, and with the standard D. The
bent lever is by means of a conducting wire connected with one pole of the
electro-magnet E and by means of a galvanometer placed in front of the latter
with one pole of the electro-magnet N.
In order that the train may be able to cause the apparatus to work automatically
the pressing apparatus represented in figure 5 is placed in the sleepers beneath the
base of the rails and a little beyond the distant switch.
This apparatus is constructed in the following manner.
One end of a rail Z situated at the said switch is supported and somewhat raised
by a spring b the greater part of which is located in a recess in the subjacent
sleeper c. In a sleeper more distant from the end of the rail is arranged a pressure
"

page_text: knob d resting on a spring e introduced into the sleeper and surrounded by &
casing, which spring, when the knob is raised is lifted a slight distance from the
adjacent contact f connected with the earth, while the spring e is connected with
the apparatus at the station. When a train is passing the rail arranged in this
manner, the end of the said rail is depressed, and the knob d is pressed against the
spring e, which thus is brought against the contact f whereby the current through
the electromagnet K of the apparatus placed at the station is closed. If necessary
several springs and several contacts may be used.
The apparatus operates in the following manner that is to say:
If a train is departing from a station it depresses, when passing over the rail Z
the end of the latter whereby the current from a battery placed at the apparatus
represented in figures 1-4 is closed by means of the electromagnet K of the
apparatus and the attachment screw 2, inasmuch as the rail when depressed also
depresses the knob
which hereby brings the spring e against the contact f. As
soon as the train has passed the movable rail, the end of the latter is raised again
by the force of the compressed spring b, whereby the contact ef is interrupted.
The signal apparatus operates thus:-The short current which is established at
the depression of the rail Z causes a current to pass through the electromagnet K
which thereby attracts the armature I placed on the hinder part of the fork shaped
arm G so that the fore-end of this fork-shaped arm with its lower leg G" is raised.
The contact spring R¹ is thus pressed against the point of contact on the bent
lever Q. This lower leg being connected with the battery by means of a con-
ducting wire to the attachment screw 5, the current of the said battery passes
through the ring O to the electromagnet E (whereby the armature secured to the
lower leg G of the fork is attracted so that the fork is retained in raised position),.
thence to the attachment screw a³, thence through the spring secured to the
metallic ring (which spring owing to the raised position of the fork, by the
turning of the shaft H is pressed against a) to the said ring and from this through
the attachment screw 3 to the circuit conducting to the apparatus of the next
station. Here the current enters into the apparatus at the attachment screw 3, and
proceeds from this to the ring O, and to spring, (which now, because the fork G is
at rest, is placed close to the screw a¹,) thence to the said screw a¹ thence to the
electromagnet N and thence to the bent lever Q against the upper contact of which
the bottom-side of the upper leg Q¹ of the fork is bearing. As now this leg by
means of a conducting wire leading to the attachment screw 4 is directly connected
with the earth, the current from Q must likewise take this course in order to
return by the earth to the battery of the former station.
At the passage of the current through the coils of the electromagnet N the
armature M is attracted, whereby the spring L connected with a local battery will
bear against the contact points of the standard D₁ one of which points, by means
of the screw 6, is connected with the outer bell and the second, by means of the
conducting wire to the screw 7, with the inner bel!. When the circuit of the
battery is thus closed the bells are caused to ring (or the hands, if such are used in
lieu of bells, are turned out of their normal position) thus signalling the arrival of a
train from the next station.
As above stated the current arriving at the bent lever Q from the lower leg Gu
of the fork proceeds directly from the said lever Q to the electromagnet E,
although the lever Q is also connected with the electromagnet N. The reason
why the current does not go to the latter is that the circuit in that direction is
interrupted at the screw a³, as the spring secured to the ring O does not bear
against the screw a' but against the screw at
.
When at the starting station the fork G is raised and the shaft H turned, the
spring fixed to the metallic ring P comes into contact with the screw a³. As now
the ring P, by means of the conducting wire to the screw 8, is connected with a
local battery, and the screw a³, by means of the conducting wire to the screw 6, is
connected with the outermost of the two signal bells, the said outermost bell
connected with the earth is, in consequence of the closing of this circuit caused to

page_text: move. A train starting from a station thus signals its departure to the next
station; so that in case a train is about to depart from the latter station the driver
is informed that there is already another train on that part of the rail-road.
་་་ ་
While the train is on its way, only the bell most remote from the starting
station is ringing but at the station to which the train is proceeding both the bells
are ringing, and will remain in action until the train has reached the depressable
rail Z at the arrival station. The train will then depress the said rail provided
with a contact device (Figure 5) and effect a contact between the springs e and f
in the manner mentioned above. An electric circuit is then closed by the electro-
magnet K and the hind-part of the fork G with the armature I is pulled 'against
the said electro-magnet K on the apparatus of the arrival station, whereby the
fore-end of the fork is raised, and the connection with the earth effected by the
contact between its upper leg and the arm O is interrupted.
.
•
The current departing from the preceding station is thus stopped whereby the
fork of the apparatus placed there, owing to the electro-magnet E having ceased to
work, falls, thus interrupting the motion of the bells as well at the departing as at
the arrival station. During the progress of the train from the latter station the
same motions are repeated by means of two other apparatuses placed one at the
departure station and another at the station to which the train is proceeding
and so on.
The two galvanometers above mentioned have for their object to show at the
station, whether there is any train on the adjacent parts of the rail-road and in
which direction this train is moving.
•
"
The said galvanometers are, as mentioned above, placed close to the electro-
magnet E and connected one with the conducting wires leading to 'this electro-
magnet and the second with those leading to the electro magnet N: When an
electric current is traversing one of these electro-magnets, the corresponding
galvanometer-needle deviates. If now the needle connected with the electro-
magnet N deviates, this indicates that a train is approaching the station, as in
this case the electric current passes through the electro magnet N but not with the
magnet E. If, on the contrary the needle connected with the magnet E deviates
this indicates, that a train is departing from the station as that produces a current
through the magnet E but not through the magnet N. If neither of the needles
deviates the line is clear.
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
First An apparatus for preventing collisions between trains consisting of a
pivotted fork G mounted on an insulated shaft H and provided at the ends with
the armatures I F; of three electro-magnets E, K, N, of which the armature M of
the one N is fixed on a spring L; of two standards D, D¹; and of a bent lever Q
provided with contact points, all of which parts are connected with each other,
with signal bells, with an apparatus of the same construction placed at another
station, and with a contact arranged in the track and acted upon by the train
as it passes...
+
Q
Second A fork G pivotted on an insulated shaft H the upper leg of which fork
is insulated and provided with a contact point and supports at its outer end a
bowl-shaped prolongation, and the lower leg of which fork is provided with a
contact spring and supports an armature F, while the hind part of the fork
supports another armature I.
Third-A shaft H supported in bearings. C and provided with two metallic
rings O, P from which two-springs project downwards, which springs according to
the position of the shaft H are brought in contact with the contact-screws a², a², a³
or at arranged, at each side of the shaft.
- 11
Fourth A bent lever Q, the upper part of which is at both sides provided with
contacts against which the ends of the legs of the fork G rest at different positions,
'

page_text: and which, besides, at their top support a bag y of india rubber and provided with
a small opening.
Fifth The combination of the electromagnet N, the armature M, the spring L,
secured to the standard D, and the divided standard D¹ situated beneath the outer
end of the spring.
Sixth A contact placed on the track and connected with the signal apparatus,
consisting of the rail end supported by a spring b located in a sleeper, and a
knob d arranged beneath the rail slightly further from the end thereof than the
spring b, which knob during the depression of the rail by the passage of a train
over it presses an adjacent bent spring e against a contact disc f placed beneath it.
HASELTINE, LAKE & Co.,
Agents for the Applicant.