Improvements in Electrical Apparatus for Railway Signals Actuated by Passing Trains.
Year: 1895

page_text: Date of Application, 20th Aug., 1895
Complete Specification Left. 30th Apr., 1896-Accepted, 30th May, 1896
PROVISIONAL SPECIFICATION.
[Communicated from abroad by Messrs. SIEMENS AND HALSKE, Berlin, Electrical
Engineers.]
Improvements in Electrical Apparatus for Railway Signals Actuated
by Passing Trains.
We, SIEMENS BROTHERS & Co. LIMITED, of 12 Queen Anne's Gate,
Westminster, in the County of London, Electrical Engineers, do hereby declare
the nature of this invention to be as follows:-
This invention relates to the construction of electrical apparatus whereby an
electrical circuit is closed or opened and a railway signal actuated by a passing
train.
We will describe the said apparatus with reference to the accompanying drawings
in which Fig. 1 shews a diagrammatic plan of part of a line of railway with the
said apparatus applied thereto, and Figs. 2 to 6 shew enlarged details of the
apparatus, which apparatus is arranged to be actuated in whichever direction.
the train is travelling, while Fig. 7 shews an arrangement in which the train
actuates a different electrical circuit according to the direction in which it
travels.
As is known, a continuous closure of a circuit can be effected during the passage
of a train by insulating one or more lengths of rail on one side of the line from the
other rails and from earth and connecting the insulated rails with one pole of a
battery, the other pole of which is connected with earth or with the opposite rails.
In this case, so long as a wheel axle is situated on the insulated rails it closes the.
circuit, in connection with which are the electrical signals or electrical disengaging,
gear.
This arrangement has however not been much made use of because it is very..
liable to careless use. Also, if the closed circuit system be employed for enabling
the insulation to be controlled it requires a considerable consumption of battery
power, as the insulation is never very perfect...
The present invention consists in a combination of this system of insulated rails
with an arrangement of contacts by depression of the rails which avoids the
disadvantages of the arrangements heretofore proposed...
In Fig. 1 the rail S is insulated in any suitable known manner from the..
contiguous and opposite rails, and near to this, preferably opposite the same, is a
contact device P operating by the depression of the rail..
The battery B has its one pole connected to earth and its other pole is connected.
through an electro magnet E with the depression contact..
The insulated, rail is ordinarily out of connection with the battery. As soon as
the first axle of a train passes over the contact P the rail is depressed and effects.
the closing, of the circuit by the raising of a column of mercury, in the known
manner as shewn at Fig. 3. The electro magnet E is thus excited and attracts its
armature, which is so arranged relatively to the insulated rail as to be thereby made
to include this in the circuit, so that if a wheel axle is at this moment situated over
the said rail, the circuit will remain closed until all the axles of the train have
passed off the rail, assuming that the insulated portion of the rail is at least as long

page_text: as the greatest distance between two axles of a train. The circuit is then broken,
the electro magnet becomes inoperative and the armature in being moved away by
a spring, the insulated rail is again cut out of the circuit.
If a fault should occur in the insulation of the rail circuit this would remain
closed even after the train had passed away, and as the armature would not be
removed from its magnet, the fault would be readily observed.
The signalling apparatus employed in connection with such a contact apparatus
for indicating whether a train has left a certain section of the line, must of course
be so arranged that its action only takes place after the circuit has been closed and
then opened again, or in other words, when the entire train has passed over the
insulated rail.
Such block signal apparatus is shewn in connection with the said contact
apparatus at Figs. 4 to 6. With this arrangement it is, as is well known, required
that the preceding section is not freed from the block before the train has actually
left the section.
For this purpose, in order to avoid long conductors there is provided in front of
the attendant's hut, an insulated rail S in combination with a depression contact P.
If now a train passes over the insulated rail, the first axle will effect the closing of
the circuit, when, by means of the known catch device K' the blocking key D is
set free for actuating the blocking apparatus. At the same time however, a second
armature actuated by the same or by a separate electro magnet moves a stop K³
under the blocking key whereby this is again locked until the circuit is opened, that
is, until the entire train has passed over the rail S, and has thus left the section
that is to be freed from the block.
Fig. 7 shews an arrangement in which there are two insulated rail sections S¹ S',
ove behind the other, each of which is separately combined with a depression
contact P P in the above described manner.
A train will consequently first effect the closing of the circuit of the one rail, will
then effect the closing of the circuits of both rails, and lastly will effect the closing
of the circuit of the second rail only, as the last axle passes over this.
Thus according to the direction of travel the one or the other circuit will be the
first to be closed, and if electro magnets with armatures be included in the circuits,
the corresponding armature will be first attracted, then both and lastly only the
second one. It will be readily understood that the variation in the sequence of
these movements can be utilised in various ways for giving different signals. At
Fig. 7. is shewn by way of example an arrangement of apparatus similar to one of
those described in the Specification to Patent No. 13492 of 1893 to be actuated by
the armatures of the electro magnets.
"
To the two armatures of the electro magnets E' and E. there are respectively
pivotted the rods L' L' which are pivotted together at the point B.
This point B will consequently, on the occurrence of the above described con-
secutive movements of the armatures pass through the paths B' B' B' B', consisting
of circular arcs, such motion taking place in a direction dependent upon whether
the one or the other armature moves first, according as the passing train travels in
one direction or the other.
According to the direction of motion of the point B the one or the other
contact H or H' will be closed so that with this arrangement a circuit closing
apparatus is provided which is made to indicate the direction of the train without
having any movable part at the rails actuated by the wheels. The connection of
the depression contacts with the respective insulated rails is effected, as before, by
means of the electro magnets E' and E' in such a manner that the closing of the
circuit is first effected by the rail depression contact, whereupon, by the
attraction of the armature the corresponding insulated rail is connected with
the battery.
Fig. 8 shews the various positions of a carriage when passing over the contact
apparatus in the direction from left to right, the corresponding positions of the
point B being marked with the same indexes as at Fig. 7.

page_text: Fig. 9 shews the corresponding position for a carriage travelling in the opposite
direction.
It will be obvious that in place of the described rail depression contacts, other
contacts actuated by the wheels might be employed, so arranged that they cannot
be actuated otherwise than by a passing train.
Dated this 20th day of August 1895.
ABEL & IMRAY,
Agents for the Applicants.
Improvements in Electrical Apparatus for Railway Signals Actuated
by Passing Trains.
We, SIEMENS BROTHERS & Co. LIMITED, of 12 Queen Anne's Gate,
Westminster, in the County of London, Electrical Engineers, 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 :-
This invention relates to the construction of electrical apparatus whereby an
electrical circuit is closed or opened and a railway signal actuated by a passing
train.
We will describe the said apparatus with reference to the drawings accompanying
our Provisional Specification in which Fig. 1 shews a diagrammatic plan of part
of a line of railway with the said apparatus applied thereto, and Figs. 2 to 6 shew
enlarged details of the apparatus, which apparatus is arranged to be actuated in
whichever direction the train is travelling, while Fig. 7 shews an arrangement
in which the train actuates a different electrical circuit according to the direction in
which it travels.
As is known, a continuous closure of a circuit can be effected during the passage
of a train by insulating one or more lengths of rail on one side of the line from
the other rails and from earth and connecting the insulated rails with one pole of
a battery, the other pole of which is connected with earth or with the opposite
rails. In this case, so long as a wheel axle is situated on the insulated rails it
closes the circuit, in connection with which are the electrical signals or electrical
disengaging gear.
This arrangement has, however, not been much made use of because it is very
liable to careless use. Also, if the closed circuit system be employed for enabling
the insulation to be controlled it requires a considerable consumption of battery
power, as the insulation is never very perfect.
The present invention consists in a combination of this system of insulated rails
with an arrangement of contacts by depression of the rails, such as that described
in Letters Patent No. 9568 of 1885 which avoids the disadvantages of the
arrangements heretofore proposed.
In Fig. 1 the rail S is insulated in any suitable known manner from the
contiguous and opposite rails and near to this, preferably opposite the same is a
contact device P operating by the depression of the rail. The battery B has its
one pole connected to earth and its other pole is connected through an electro
magnet E with the depression contact. The insulated rail is ordinarily out of
connection with the battery. As soon as the first axle of a train passes over the
contact P the rail is depressed and effects the closing of the circuit by the raising
of a column of mercury, in the known manner as shewn at Fig. 3. The electro
magnet E is thus excited and attracts its armature, which is so arranged relatively
to the insulated rail as to be thereby made to include this in the circuit, so that if
a wheel axle is at this moment situated over the said rail which must be the case
owing to the position given to the depression contact device, the circuit will
remain closed until all the axles of the train have passed off the rail, assuming that

page_text: .
the insulated portion of the rail is at least as long as the greatest distance between
two axles of a train. The circuit is then broken, the electromagnet becomes
inoperative and the armature being moved away by a spring, the insulated rail is
again cut out of the circuit.
If a fault should occur in the insulation of the rail circuit this would remain
closed even after the train had passed away, and as the armature would not be
removed from its magnet, the fault would be readily observed. The signalling
apparatus employed in connection with such a contact apparatus for indicating
whether a train has left a certain section of the line, must of course be so arranged
that its action only takes place after the circuit has been closed and then opened
again, or in other words, when the entire train has passed over the insulated rail.
Such block signal apparatus is shewn in connection with the said contact
apparatus at Figs. 4 to 6. With this arrangement it is, as is well known, required
that the preceding section is not freed from the block before the train has actually
left the section.
For this purpose in order to avoid long conductors there is provided
in front of the attendant's hut an insulated rail S in combination with a depression
contact P. If now a train passes over the insulated rail the first axle will effect
the closing of the circuit when by means of the known catch device K' the blocking
key D is set free for actuating the blocking apparatus. At the same time however
a second armature actuated by the same or by a separate electro magnet moves a
stop K under the blocking key whereby this is again locked until the circuit is
opened, that is, until the entire train has passed over the rail S and has thus left
the section that is to be freed from the block.
Fig. 7 shews an arrangement in which there are two insulated rail sections S' S'
one behind the other each of which is separately combined with a depression
contact P¹ P' in the above described manner, by which arrangement the direction
of the current is dependent on the direction of the train.
A train will consequently first effect the closing of the circuit of the one rail,
will then effect the closing of the circuits of both rails, and lastly will effect the
closing of the circuit of the second rail only as the last axle passes over this.
Thus according to the direction of travel the one or the other circuit will be the
first to be closed, and if electro magnets with armatures be included in the
circuits the corresponding armature will be first attracted, then both and lastly
only the second one. It will be readily understood that the variation in the
sequence of these movements can be utilised in various ways for giving different
signals. At Fig. 7 is shewn by way of example an arrangement of apparatus
similar to one of those described in the Specification to Patent No. 13492 of 1893
to be actuated by the armatures of the electro-magnets.
To the two armatures of the electro magnets E' and E' there are respectively
pivotted the rods L' L' which are pivotted together at the point B.
This point B will consequently on the occurrence of the above described
consecutive movements of the arinatures pass through the paths B' B' B' B*,
consisting of circular ares such motion taking place in a direction dependent upon
whether the one or the other armature moves first according as the passing train
travels in one direction or the other.
According to the direction of motion of the point B the one or the other
contact H or H' will be closed so that with this arrangement a circuit closing
apparatus is provided which is made to indicate the direction of the train without
having any movable part at the rails actuated by the wheels. The connection of
the depression contacts with the respective insulated rails is effected as before by
means of the electro magnets E' and E in such a manner that the closing of the
circuit is first. effected by the rail depression contact whereupon by the attraction
of the armature the corresponding insulated rail is connected with the battery.
Fig. 8 shews the various positions of a carriage when passing over the contact
apparatus in the direction from left to right, the corresponding positions of the
point B being marked within brackets by the side.

page_text: Fig. 9 shews the corresponding positions for a carriage travelling in the opposite
direction.
It will be obvious that in place of the described rail depression contacts, other
contacts actuated by the wheels might be employed, so arranged that they cannot
be actuated otherwise than by a passing train.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In electrical apparatus for railway signals actuated by passing trains, the
combination with a depression contact such as P, or similarly acting contact, closing
a local circuit of an insulated length of rail such as S, and an electro magnet such
as E, adapted to operate the signals, these parts being so arranged that on the
closing of the depression contact by a passing train the electromagnet is excited
and is caused by its armature to close a second contact which includes the insulated
rail in the circuit whereby the circuit is maintained closed and the signal operated
so long as a wheel of the passing train is upon the insulated rail substantially as
described.
2. The modification of the apparatus referred to in the first claim consisting in
the employment of two separate lengths of insulated rail and two corresponding
depression contacts and operating electromagnets, these parts being so arranged to
operate consecutively in different sequence according as the train passes in one
direction or the other, substantially as described.
Dated this 20th day of 1906
ABEL & IMRAY,
Agents for the Applicants.