Improvements in Apparatus for Working Railway Switches and Signals by Means of Electrical Energy.
Year: 1895

page_text: Date of Application, 4th June, 1895
Complete Specification Left, 27th Feb., 1896-Accepted, 28th Mar., 1896
PROVISIONAL SPECIFICATION.
[Communicated from abroad by Messrs. SIEMENS
HALSKE, of Berlin, in the
German Empire, Electrical Engineers.]
Improvements in Apparatus for Working Railway Switches and
Signals by Means of Electrical Energy.
We, SIEMENS BROTHERS & Co. LIMITED, of 12 Queen Anne's Gate,
Westminster, in the County of Middlesex, Electrical Engineers, do hereby declare
the nature of this invention to be as follows:-
In the Specifications to Patent No. 4976 of 1893 and No. 22570 of 1893 were
described apparatus for moving switches and signals from one position to another
by electrical energy, and for controlling such apparatus and indicating the proper
performance of their functions.
The present invention relates to improvements in such actuating, controlling and
indicating devices, whereby an increased security of working is obtained.
For the better understanding of the improvements we have shewn on the
accompanying drawing the general arrangement of the working apparatus and
safety indicating appliances as they were described in the Specification to the
above mentioned Patent No. 22570 of 1893, as applied to the working of switches,
but it is to be understood that the devices are equally applicable to signal
apparatus.
The apparatus is worked by means of three leads, as was the case in the said
prior Patents, namely two being supply leads and the third the return lead.
The first two can be put alternately in connection with the one pole of the
electric generator by means of the contact switch a while the arrangement of the
apparatus is such that when the required work has been performed for bringing
the points or signal into the required position, a reversal of the connections is
automatically effected which arrests the motion, but prepares the apparatus for
either the return motion or a farther movement in the same direction, that is to
say, the motor engine which was before connected to the one supply lead, is now
connected to the other lead.
Each end position of the switch a therefore corresponds to a certain position of
the operative devices.
The controlling or indicating devices which have to indicate the proper working
of the apparatus consist firstly of an electromagnet apparatus c arranged between
tle two supply leads, the armature of which is electrically or mechanically connected
with the reversing switch a and a resistance cut-out contact e, and secondly in the
arrangement of an earth connection at the pole of the electric generator which is
in connection with the two supply leads. The differences between this arrangement
and that of the before mentioned prior Patents consist firstly in the fixed arrange-
ment of the electromagnet device c between the two supply leads and 12, so that
only a single switch is here necessary in place of a double one as in the former
Patents, and secondly, in the peculiar mechanical interdependence between the
control armature c', the switch a and the resistance cut-out contact e.
Furthermore, the earth connection of the generator pole that is connected to the
supply leads, is new.
The action of the said devices will be understood on following the direction

page_text: of the current during the several phases that occur before, during and after a
reversal of the apparatus.
In the state of rest Fig. 1 the lead which is connected by switch a with the
positive pole of the electric generator, is interrupted at the electro motor, as the
brush which is connected with this lead is raised off the commutator. On
the other hand, the second lead 2 which is out of connection with the switch a
connected with the negative pole of the generator through the electro motor, cr an
electromagnet replacing the same.
As the winding of the control electromagnet e is connected between the two
leads and 12 of which, as described, one is in conducting connection with the
positive and the other with the negative pole of the generator, a current must flow
through the same, and consequently the armature c' is attracted.
This armature is so connected with the resistance cut out contact e that the
resistance is included in the circuit when the armature c' is attracted by the magnet c,
and cannot be cut out when the armature is released.
This relation between the contact e and the armature c¹ can of course be carried
out in a variety of ways, one of which is shewn diagrammatically on the drawing
and which will be readily understood. Therefore, in the position of rest, when
the armature c' is attracted, the considerable resistance W is included in the return
lead. The current will consequently be very weak and not capable of actuating
the motor; but the direction of the current will be the same as that of the working
current which subsequently actuates the motor. The existence of the indicating
current will therefore shew that the working current, to be put subsequently into
action, will work correctly. As furthermore the reversing devices of the motor
are connected with the signals, points &c. so as to act in a definite manner, on these
being moved, as described in the Specification to Patent No. 22570 of 1893, any
deviation of the points &c. from the correct position will effect the cutting out of
the indicating current from the indicating electromagnet c.
The attracted armature c¹ of the magnet will therefore shew firstly the correct
connection of the circuit for the future working current, and secondly the correct
position of the working devices. The latter function renders the armature cl
suitable for effecting the interdependence which should exist between the correct
position of one working device and that of a second one.
Thus the signal indicator circuits can be connected through the signal cut-
sut d on the indicator armatures of the corresponding points (Fig. 4) so that when
these points leave the correct position such for instance as by being forced open
by a train, the signal circuit will be broken and the signal be brought to the
danger position by any known device. Fig. 4 shews a diagram of such a signal
circuit.
The indicator armature c¹ is provided with a locking device acting on the
reversing switch a, such as the part b Figs. 1, 2, 3, that is brought in the path of
the switch when the armature is not attracted, and consequently only allows the
switch to be moved when the armature is attracted and the working devices are
in order.
As the armature also falls away during the working of the motor (Fig. 2) this
locking device also prevents the switch from being moved so as to prevent the
motor from completing the required motion.
.
In order to obtain a strong current for working the motor, the resistance W
must be cut out, which is effected by the movement of the short circuiting contact e.
The resistance is put in circuit, by the attraction of the armature as above
described, but it is only put out of circuit by the reversal of the switch a, which is
for this purpose made to act upon the contact e. As will be seen, the switch a, at
each movement, brings the contact e into the position in which the resistance is
cut out. This movement must be followed by the armature c as this is actuated
by the former by means of the elbow lever h. The movement of the armature
away from the magnet during the reversal of the connections is consequently a
forced one.

page_text: This combination of the cut out contact e with the switch a on the one hand and
with the armature c¹ on the other hand, is of great importance for the security of
working; as the resistance W can only be cut out by means of the switch and as
the latter can only be moved when the armature is attracted, it is evident that it
is quite impossible that by accident a strong current should enter the circuit beyond
the switch.
As, by the reversal of the switch a, not only is the contact e moved, but also the
armature c is removed from the electromagnet c, it cannot happen that the armature
remains attached.
If this latter could occur, it would be possible that any derangement of the parts
would have no effect upon the signal cut-out d connected with the armature
(Fig. 4).
Thus it will be seen from the above that upon the position of the indicator
arniature e will depend the working of the switch a as also the security of the
entire working; it is therefore of the greatest importance to prevent under all
circumstances the passage of current into the windings of the electro magnet c
otherwise than by the prescribed way.
This might for instance occur if simultaneously in the return lead and in the
supply lead through which the indicating current is passing, namely for example
at points P, Fig. 3, there should exist a fault in the insulation, that is to say, earth
contacts.
It would then be possible for the indicating current to find a closed circuit
without passing through the motor also in the case when the working devices were
not in correct position, thus directly giving rise to the danger of accidents.
This can be prevented by the following arrangement.
If the pole of the current generator nearest the indicator electromagnet be put
to earth, it will be evident that under no circumstances can a current derived from
an imperfectly insulated place in the conductor pass through the winding of the
indicator maguet as thèse would be at the same potential as the earth. At the
same time, any such fault can be at once recognised if a galvanometer be introduced
behind the resistance W. If this indicates a current while the electromagnet is
without current, there must be a dead earth.
Smaller faults of insulation could only be indicated by the use of a second
galvanometer in the indicator magnet circuit. The potential difference existing
between the two would indicate the loss through defective insulation. For the
present case however, where it is not a question of accurate measurements, a
simple means exists in the use, for the resistance W, of one or more glow lamps.
The resistance is so regulated that the lamps of all working devices of the same
locality shew the same dark red glow when the circuit is in good order. As soon
as a considerable insulation fault occurs in a lead, the corresponding lamp will
shew, a brighter light than the others.
The introduction of the resistance W in the branch of the circuit not connected
to earth has the farther advantage that the potential differences between the
circuit and earth will be very small, and are only considerable during the working
of the motor, whereby the ready production and maintenance of all insulations is
facilitated.
The connection to earth of the pole of the generator which is connected with the
supply leads, instead of the usual connection of the return lead with earth, is
therefore an essentially valuable improvement.
A farther security is afforded by the cut-out switch N on the return lead. This
cut-out can be put in connection with the working devices in such manner, that it
is thrown out at each irregularity of motion; but is not put in circuit again by the
return motion. This cut out, as also other cut outs may serve for communication
between the operators at the points or signals and those at the central station, as
every short interruption of the indicating circuit produces an audible clicking of
the electro magnet armature.
Lastly, all the indicator armatures of a central station apparatus can be included

page_text: in a bell circuit g, so that the bell will be sounded as long as one of the armatures
is removed from its magnet.
In regular working this bell will sound as long as a motor works, that is to say,
a certain short time after reversal of a switch, and it will ring continuously when
an indicator circuit is interrupted. The indicator armatures being provided with
coloured signal discs, the fault can at once be localised.
Fig. 3 shews the position of the apparatus on the interruption of the indicator
circuit.
The armature c¹ being removed and the switch a consequently locked thereby,
while the resistance W is included in the circuit.
In the general diagram Fig. 4 the motor which actuates signal A' is just in
motion; the working current is indicated by double arrows.
Dated this 4th day of June 1895.
ABEL & IMRAY,
Agents for the Applicants.
Improvements in Apparatus for Working Railway Switches and
Signals by Means of Electrical Energy.
We, SIEMENS BROTHERS & Co. LIMITED, of 12 Queen Anne's Gate,
Westminster, in the County of Middlesex, Electrical Engineers, do hereby
declare the nature of this invention and in what manner the same is to he
performed to be particularly described and ascertained in and by the following
statement :-
In the Specifications to Patents No. 4976 of 1893 and No. 22570 of 1893 were
described apparatus for moving switches and signals from one position to another
by electrical energy, and for controlling such apparatus and indicating the proper
performance of their functions.
The present invention relates to improvements in such actuating, controlling and
indicating devices, whereby an increased security of working is obtained.
For this purpose the apparatus is provided with two supply leads for conveying
the electrical energy to the motor that actuates the switches or signals, and with
one return lead, as in the arrangements described in the said prior Specifications
and there is introduced between the two supply leads an electromagnet whose
armature is attracted whether a weak or a strong current is passed through the
apparatus and only falls away if there is an insulation fault in the leads, this
electromagnet consequently indicates that the apparatus is in working order, so long
as the armature remains attracted.
An operating switch connected to the one pole of a current generator is adapted
to make contact with either of the two supply leads; when moved so as to make
contact with the one lead, a contact device in connection with the return lead, in
being moved by the attracted armature of the said electromagnet, makes such
connection between the return lead and a current generator that only a weak
current is made to pass through the apparatus, sufficient to excite the electromagnet
and keep the armature attracted, but not sufficient to actuate the electromotor.
If, on the other hand, the operating switch is moved over to the second supply lead
for the purpose of actuating the motor, it is at the same time made to act upon the
said contact device so as to cause this to make such connection between the return
lead and the current generator that a strong current is passed through the apparatus
so as to bring the motor into action. For the better understanding of the improve-
ments, we have shewn on the drawing accompanying our Provisional Specification,
the general arrangement of the working apparatus and safety indicating appliances

page_text: as they were described in the Specification to the above mentioned Latent
No. 22570 of 1893, as applied to the working of switches, but it is to be understood
that the devices are equally applicable to signal apparatus.
The apparatus is worked by means of three leads, as was the case in the said
prior Patents, namely, two being supply leads and the third the return lead.
The first two can be put alternately in connection with the one pole of the
electric generator by means of the contact switch a while the arrangement of the
apparatus is such that when the required work has been performed for bringing
the points or signal into the required position, a reversal of the connections is
automatically effected which arrests the motion, but prepares the apparatus for
either the return motion or a farther movement in the same direction, that is to say,
the motor engine which was before connected to the one supply lead, is now
connected to the other lead. Each end position of the switch a therefore.
corresponds to a certain position of the operative devices.
The controlling or indicating devices which have to indicate the proper working
of the apparatus consists, firstly, of an electromagnet apparatus c arranged between
the two supply leads, the armature of which is electrically or mechanically
connected with the reversing switch a and a contact device e h by means of which,.
as before stated, either a weak or a strong current is passed through the apparatus,
and secondly, in the arrangement of an earth connection at the pole of the electric
generator which is in connection with the two supply leads.
The differences between this arrangement and that of the before mentioned
prior Patents consists firstly in the fixed arrangement of the electromagnet device c
between the two supply leads and 2 so that only a single switch is here necessary
in place of a double one as in the former Patents, and secondly in the peculiar
mechanical interdependence between the control armature c', the switch a and the
contact device e h.
Furthermore, the earth connection of the generator pole that is connected to the.
supply leads, is new.
The action of the said devices will be understood on following the direction of
the current during the several phases that occur before, during and after a reversal
of the apparatus.
=
In the state of rest Fig. 1 the lead which is connected by switch a with the
positive pole of the electric generator, is interrupted at the electromotor, as the
brush which is connected with this lead is raised off the commutator. - On.
the other hand, the second lead 2 which is out of connection with the switch a is
connected with the negative pole of the generator through the electro motor, or an
electromagnet replacing the same.
As the winding of the control electromagnet c is connected between the two.
leads and of which, as described, one is in conducting connection with the
positive and the other with the negative pole of the generator, a current must flow
through the same and consequently the armature c' is attracted. This armature is
so connected with the contact device e that the resistance is included in the
circuit when the armature c¹ is attracted by the magnet c, and cannot be cut out
when the armature is released.
This relation between the contact e and the armature c¹ can of course be carried
out in a variety of ways, one of which is shewn diagrammatically on the drawing
and which will be readily understood. Therefore, in the position of rest, when
the armature c is attracted, the considerable resistance W is included in the return.
lead 13.
The current will consequently be very weak and not capable of actuating the
motor, but the direction of the current will be the same as that of the working
current which subsequently actuates the motor.
The existence of the indicating current will therefore shew that the working
current, to be put subsequently into action, will work correctly.
As, furthermore, the reversing devices of the motor are connected with the

page_text: signals, points &c. so as to act in a definite manner, on these being moved as
described in the Specification to Patent No. 22570 of 1893, any deviation of the
points &c. from the correct position will effect the cutting out of the indicating
current from the indicating electro magnet c.
The attracted armature c' of the magnet will therefore shew firstly, the correct
connection of the circuit for the future working current and secondly, the correct
position of the working devices.
The latter function renders the armature c' suitable for effecting interdependence
which should exist between the correct position of one working device and that of
a second one.
Thus the signal indicator circuits can be connected through the signal cut-out d
on the indicator armatures of the corresponding points (Fig. 4) so that when these
prints leave the correct position such for instance as by being forced open by a
train, the signal circuit will be broken and the signal be brought to the danger
position by any known device.
Fig. 4 shews a diagram of such a signal circuit.
b
The indicator armature c¹ is provided with a locking device acting on the
reversing switch a such as the part 6 Figs. 1, 2, 3 and 5 that is brought in the path
of the switch when the armature is not attracted, and subsequently only allows the
switch to be moved when the armature is attracted and the working devices are in
order.
As the armature also falls away during the working of the motor (Fig. 2) this
locking device prevents the switch from being moved so as to prevent the motor
from completing the required motion.
In order to obtain a strong current for working the motor, the resistance W must
be cut out, which is effected by the movement of the short circuiting contact e.
The resistance is put in circuit by the attraction of the armature as above described,
but it is only put out of circuit by the reversal of the switch a, which is for this
purpose made to act upon the contact e. As will be seen, the switch a, at each
movement, brings the contact e into the position in which the resistance is cut out.
This movement must be followed by the armature c¹ as this is actuated by the
former by means of the elbow lever h.
The movement of the armature away from the magnet during the reversal of the
connections is consequently a forced one.
This combination of the cut out contact e with the switch a on the one hand and
with the armature et on the other hand, is of great importance for the security of
working as the resistance W can only be cut out by means of the switch and as
the latter can only be moved when the armature is attracted, it is evident that it is
quite impossible that by accident a strong current should enter the circuit beyond
the switch.
As, by the reversal of the switch a, not only is the contact e moved, but also the
armature c¹ is removed from the electro magnet c, it cannot happen that the
armature remains attached.
If this latter could occur, it would be possible that any derangement of the parts
would have no effect upon the signal cut-out d connected with the armature
(Fig. 4).
Thus it will be seen from the above that upon the position of the indicator
armature will depend the working of the switch a as also the security of the
entire working; it is therefore of the greatest importance to prevent under all
circumstances the passage of current into the windings of the electro magnet c
otherwise than by the prescribed way.
This might for instance occur if simultaneously in the return lead and in the
supply lead through which the indicating current is passing, namely for example
at points P, Fig. 3, there should exist a fault in the insulation, that is to say, earth
contacts.
It would then be possible for the indicating current to find a closed circuit

page_text: without passing through the motor, also in the case when the working devices
were not in correct position, thus directly giving rise to the danger of accidents.
This can be prevented by the following arrangement :-
If the pole of the current generator nearest the indicator electromagnet be put
to earth, it will be evident that under no circumstances can a current derived from
an imperfectly insulated place in the conductor pass through the windings of the
indicator magnet, as those would be at the same potential as the earth. At the
same time any such fault can be at once recognised if a galvanometer be introduced
behind the resistance W. If this indicates a current while the electromaguet is
without current, there must be a dead earth.
Smaller faults of insulation could only be indicated by the use of a second
galvanometer in the indicator magnet circuit. The potential difference existing
between the two would indicate the loss through defective insulation. For the
present case however, where it is not a question of accurate measurements, a
simple means exists in the use, for the resistance W, of one or more glow lamps.
The resistance is so regulated that the lamps of all working devices of the same
locality shew the same dark red glow when the circuit is in good order. As soon
as a considerable insulation fault occurs in a lead, the corresponding lamp will
shew a brighter light than the others.
The introduction of the resistance W in the branch of the circuit not connected
to earth has the farther advantage that the potential differences between the circuit
and earth will be very small, and are only considerable during the working of the
motor, whereby the ready production and maintenance of all insulations is
facilitated.
The connection to earth of the pole of the generator which is connected with the
supply leads, instead of the usual connection of the return lead with earth is
therefore an essentially valuable improvement.
A farther security is afforded by the cut-out switch N ou the return lead. This
cut out can be put in connection with the working devices in such manner that it
is thrown out at each irregularity of motion; but it is not put in circuit again by
the return motion. This cut out, as also other cut outs, may serve for communi-
cation between the operators at the points or signals and those at the central
station, as every short interruption of the indicating circuit produces an audible
click of the electromagnet armature.
Lastly, all the indicator armatures of a central station apparatus can be included
in a bell circuit g, so that the bell will be sounded as long as one of the armatures
is removed from its magnet. In regular working this bell will sound as long as a
motion works, that is to say, a certain short time after reversal of a switch, and it
will ring continuously when an indicator circuit is interrupted. The indicator
armatures being provided with coloured signal discs, the fault can at once be
localised.
Fig. 3 shews the position of the apparatus on the interruption of the indicator
circuit.
The armature c¹ being removed and the switch a consequently locked thereby,
while the resistance W is included in the circuit.
In the general diagram Fig. 4, the motor which actuates signal A² is just in
motion; the working current is indicated by double arrows.
As the object of the resistance W is merely to cause a weak indicator current to
pass through the circuit when the apparatus is at rest, instead of the full current,
it will be readily understood that any other device that will accomplish this object
may be substituted for the resistance W without departing from the essential
feature of the invention. Thus, for instance, the device shewn at Fig. 5, on the
accompanying drawing may be used for the purpose, which figure shews the parts
in the same position as at Fig. 1.
In this arrangement, when the switch a and lever h are in the position shewn, in
which a weak indicator current is required to pass through the apparatus, the
contact switch e connected to h makes contact between the return lead and a

page_text: lead connected to the negative pole of a weak battery or current generator al.
When on the other hand the switch a is moved over to contact 2 for putting the
motor in action, and consequently moves the lever h as described with reference to
Fig. 2, the contact switch, e, is caused to make connection between lead 13 and
lead connected to the negative pole of a strong current generator x.
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 apparatus for working railway switches and signals by means of electrical
energy of the kind herein referred to, a controlling and indicating apparatus
consisting in the introduction of an indicator electromagnet such as e, between the
two leads supplying the motor, such electromagnet being so arranged that by the
fact of its excitation, as shewn by the attraction of its armature, it is made to
indicate that the apparatus is in proper working order, and that the actuating
motor will operate in the desired manner, substantially as described.
2. In the controlling and indicating apparatus referred to in the first claim, the
combination with the indicator electromagnet c and its armature c¹ of the stopping
and starting switch a connected with the one pole of the current generator, and a
contact device, such as h, e so arranged in connection with the return lead of the
electromotor, that when the switch a is moved into the position for throwing the
motor out of action, the said contact device is actuated so as to make contacts
whereby a weak current is passed through the apparatus only sufficient to excite
the indicator electromagnet, while when the switch is turned into the position for
bringing the motor into action the contact device is moved so as to cause a strong
current to be supplied to the motor substantially as described.
3. In apparatus such as is referred to in the preceding claim, so arranging the
armature cof the electro magnet c in connection with the controlling switch a that
in the event of the electro magnet being thrown out of action in consequence of an
insulation fault while the switch a is in the position for passing a weak current
through the apparatus, the said armature prevents the switch a and contact
device h, e from being moved over into the position for sending a strong current
through the apparatus substantially as described.
4. In apparatus such as is referred to in the preceding claims, providing the
pole of the current generator to which the operating switch a is connected with an
earth connection, for the purpose of preventing any incorrect action of the control
electro-magnet c in consequence of an insulation fault in the leads of the apparatus,
substantially as described.
Dated this 7th 1.
T 1.
1000
ABEL & IMRAY,
Agents for the Applicants.