An Improved Means of Underground Current Supply for Electric Railways.
Year: 1893

page_text: Date of Application, 19th Dec., 1893
Complete Specification Left, 23rd Aug., 1894-Accepted, 1st Dec., 1894
An Improved Means of Underground Current Supply for Electric
Railways.
A communication by AUGUST RAST, of 9, Gugelstrasse, Nuremberg, in the Empire
of Germany, Mechanic.
I, WILLIAM PHILLIPS THOMPSON F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool and 6, Bank Street, Manchester,
both in the County of Lancaster and 323 High Holborn, in the County of Middlesex,
Civil Engineer do hereby declare the nature of this invention to be as follows:-
This invention has for its object an improved means of underground current
supply for electric street railways. It is applicable to any kind of electric railway
in which the supply of the current takes place by means of an underground
conductor in such a way that the current is supplied to a centre rail, consisting of
insulated sections, and is taken therefrom at any point where the car may be at the
moment by means of friction brushes, and then flows through the motor and returns
to the dynamo through the ordinary rails of the permanent way.
The main disadvantage of similar arrangements hitherto employed consists in the
openings which exist between the sections of the centre rail and its insulators, by
means of which water can penetrate to the underground conducting mechanism,
thus causing the formation of rust and short circuiting.
This improved device consists of a centre rail in sections insulated one from
another, with each of which a fully closed box is connected in such a way as to be
watertight. An electro-magnetic apparatus is contained in this box, and is
connected with the main conductor by means of a supply wire, which is watertightly
inserted into the box. The electro-magnet consists of a coil, the wire of which
forms a continuation of the supply wire. The armature of this electromagnet
consists of an iron core vertically supported in the coil, which core carries at its
upper end a metal brush, curved with its two euds upwards, which is connected
with the fixed coil by means of a flexible connection. Between the upwardly
curved arms of this brush or circuit closer, a piece of iron in the form of a screw
head or nut or the like is fastened. On the under side of the motor carriage, there
are arranged a permanent magnet and a contact brush, and these slide, together
with the carriage, over the centre rail sections.
If then the carriage passes over the closed box, the head piece or armature of the
core of the electromagnet is attracted by the said permanent magnet, and the
armature is immediately raised in such a way that a flexible connection is established
between its metal brush and the section of the centre rail. In the meantime, the
contact brush of the motor has also come on to the same section. As the brush of
the armature is connected by means of a flexible connection, as aforesaid, with the
supply wire and thereby with the main conductor, the main circuit is thus closed,
and flows through the coil of the electromagnet, and causes the iron core of the
latter and its metal brush to press firmly against the section. The main current,
therefore, flows from the main conductor into the box to the magnet coil, thence
through the flexible connection and armature brush to the section of the centre rail,
and from there through the motor brush and conductor to the motor, and from here
through brushes and the motor wheels to the rails of the permanent way, and thence
by a conductor back to the dynamo.
When the motor carriage has passed over the section, the core of the electro
magnet drops back into its normal or non-working position, whilst the process

page_text: hereinbefore described is repeated at the next section, and the current supply
connected therewith, so that the current is only exposed at each section of the
centre rail over which the motor carriage is at the moment passing.
In order to facilitate the raising of the armature by means of the permanent
magnet of the motor, the former is seated on a spring, which imparts an upward
movement to the armature, by means of which the lifting of the latter is considerably
facilitated.
The armature may also be assisted in its movement by other suitable means than
the spring.
In order to produce easily and certainly the raising of the armature, the device
may also be arranged as follows:-
:-
The electromagnet is provided with two wire coils. The outer coil forms the
continuation of the supply wire, whilst the inner coil is made of thin wire and is
connected with a relay. This relay is formed of an iron bar vertically held in an
insulating support, and the lower end of this bar is connected with the supply wire
by means of a thin spring connection, and is further provided with a contact piece
capable of making contact with the wire leading to the thin coil of the electromagnet.
This device works in the following manner: If the motor carriage with its.
permanent magnet pass over the relay in the closed box, the small iron bar of the
relay is raised by the magnet, thereby closing the contact and a weak shunt current
passes from the conductor through the thin wire of the inner coil of the electro
magnet and out to the main conductor by a suitable connection. This at once
raises the armature in such a way that an electrical contact is established between
the metal brush of the same and the section of the centre rail.
Dated this 18th day of December 1893.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improved Means of Underground Current Supply for Electric
Railways.
A communication by AUGUST RAST, of 9, Gugelstrasse, Nuremberg, in the Empire
of Germany, Mechanic.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and 6, Bank Street, Manchester,
both in the County of Lancaster and 323 High Holborn in the County of Middlesex,
Civil Engineer 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 has for its object an improved means of underground current
supply for electric street railways. It is applicable to any kind of electric railway
in which the supply of the current takes place by means of an underground
conductor in such a way that the current is supplied to a centre rail, consisting of
insulated sections, and is taken therefrom at any point where the car may be at the
moment by means of friction brushes, and then flows through the motor and returns
to the dynamo through the ordinary rails of the permanent way.
The main disadvantage of similar arrangements hitherto employed consists in the
openings which exist between the sections of the centre rail and its insulators, by
means of which water can penetrate to the underground conducting mechanism,
thus causing the formation of rust and short circuiting.
In the accompanying drawings,
Figure 1 is a longitudinal section of the improved device;
Figure 2 a longitudinal section of a modification of same;

page_text: Figure 3, a longitudinal section of another modification;
Figure 4, a cross section of the track with diagram showing the flow of the
current.
The
This improved device, as shown in Figures 1, 2 and 3, consists of a centre rail
in sections a¹ a² a insulated one from another, with each of which a fully closed
box is connected in such a way as to be watertight. An electro-magnetic
apparatus is contained in this box, and is connected with the main conductor by
means of a supply wire d which is watertightly inserted into the box.
electro-magnet consists of a metallic bobbin f, the wire coil e of which forms a
continuation of the supply wire d. The armature of this electro-magnet consists
of an iron core vertically supported in the bobbin which core carries at its
upper end a metal brush i curved with its two ends upwards, which is connected
with the fixed coil e by means of a flexible connection k. Between the upwardly
curved arms and of this brush or circuit closer i a piece of iron h¹ in the form
of a screw head or nut or the like is fastened. On the under side of the motor
carriage, there are arranged a permanent magnet p and a contact brush q (both
shown in dotted lines) and these slide, together with the carriage, over the centre
rail sections a a¹ n² a³.
g
If then the carriage passes over the closed box 6, the head piece or armature h¹
of the core of the electro-magnet is attracted by the said permanent magnet p, and
the armature with the core is immediately raised in such a way that a flexible
connection is established between its metal brush i and the section a or a' of the
centre rail. In the meantime, the contact brush 9 of the motor has also come on
to the same section. As the brush i of the armature is connected by means of a
flexible conuection k as aforesaid, with the supply wire d and thereby with the
main conductor c the main circuit is thus closed, and current flows through the
coil of the electro-magnet f and causes the iron core h of the latter and its
metal brush i to press firmly against the section a. The main current, therefore,
as shown in Figure 4 flows from the main conductor c into the box 6 to the magnet
coil e, thence through the flexible connection k and armature brush i to the section a
of the centre rail, and from there through the motor brush q and conductor to
the motors and from here through the wire t, the brushes u and the motor wheels v
to the rails of the permanent way, and thence by a conductor w back to the
dynamo y.
When the motor carriage has passed over the section a², the core of the
electro-magnet drops back into its normal or non-working position, whilst
the process hereinbefore described is repeated at the next section, and the current
supply connected therewith, so that the current is only exposed at each section of
the centre rail over which the motor carriage is at the moment passing.
In order to facilitate the raising of the armature of the core h by means of the
permanent magnet p of the motor, the former is seated on a spring F which tends
to press the armature upward, by means of which the lifting of the latter is
considerably facilitated.
The armature may also be counterbalanced or assisted in its movement by other
suitable means than the spring F.
In order to produce easily and certainly the raising of the armature and its
core h, the device may also be arranged as shown in Figure 2. The bobbin f of
the electro-magnet is provided with two wire coils e and g. The outer coil e forms
the continuation of the supply wire d, whilst the inner coil g is made of thin wire
and is connected with a relay. This relay is formed of an iron bar / vertically
held in an insulating support, and the lower end of this bar is connected with the
supply wire d by means of a thin spring conductor m and is further provided with
contact pieces n and o capable of making contact with the wire g leading to the
thin coil of the electro-magnet f.
This device works in the following manner :
If the motor carriage with its permanent magnet p pass over the relay in the
closed box 6 the small iron bar 1 of the relay is raised by the maguet p, thereby

page_text: closing the contact n and o and a weak shunt current passes from the conductor
through the thin wire m to the inner coil g of the electro-magnet fand out to the
main conductor by a suitable connection z. This at once raises the armature / in
such a way that an electrical contact is established between the metal brush i of
the same and the section a² of the centre rail.
Still another form of construction is shown in Figure 3 in which the raising of
the armature h and thereby the closing of the main current circuit may be produced
without the use of the magnet p carried on the carriage, or of the shunt closing
device l.
For this object a contact brush is employed for taking current from the con-
ducting rail, which brush is so formed that the front end of the same already rests
on the next section of conducting rail which is to be run over, whilst the rear end
is still in contact with the section charged with current.
A second armature is employed within a bobbin f¹ round which the main
current conductor d is wound before it reaches the bobbin f of the main armature.
The armature when in a position of repose rests on the bottom of the box b,
and the latter is in this case brought into conducting connection with the section
of rail belonging thereto. The opposite end of the armature is connected with the
thin shunt conductor g.
The form of construction herein before described of this improved device works
in the following manner.
In the position shown in the drawing in which the contact brush or roller q' has
just reached the section a² and still is in connection through its rear part with the
previous section a³, such brush imparts current to the section a'. This current is
conducted through the box 6 to the armature h' and from here to the thin coil g of
the bobbin and causes the armature of the latter to rise. The spring i con-
sequently comes in contact with the rail section a² and closes the main circuit.
At the moment in which the main circuit is closed, the armature h' is raised, its
connection with the box is thereby broken and the shunt conductor 9 is
switched off.
The armature h is then only retained in an elevated position by the main
conductor. As soon as the contact brush or roller leaves the section a³ the main
conductor is disconnected or switched off, the armatures and ¹ consequently
descend, and thereby the entire section becomes currentless.
Further in order to allow of the armature being raised in the case of an
unintentional or unforseen interruption of the main current circuit, for instance by
the carriage leaving the rails of the track, the relay / described in Figure 2 may
also be employed as a reserve in Figure 3. In this case this relay is again
connected with the branch conductor 9, and in case of need set in action by means
of a magnet, battery, accumulator or the like, which is carried on the carriage and
may be switched into the current circuit.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :-
1. An improved means of underground current supply for electric railways,
consisting of a centre rail in sections having a box (6) tightly closed on all sides
arranged below each section, each box containing an electro-magnetic current
closing device, which consists of a magnet bobbin (f) with a main current coil (e)
and a movable armature (/) whereby on the motor carriage passing over the
armature the latter is raised and the closing of the circuit effected by means of its
metallic brush i, substantially as described & shown.
2. A modification of the means for current supply by means of magnets described
in Claim 1, consisting in the employment of a second electro-magnet (f¹ h³)
inserted in the main circuit, one end of the armature of such second magnet being
connected with a shunt conductor (9) and the other end being brought into con-
ducting connection with the rail section belonging thereto, so that when the said

page_text: armature is in its normal position of rest the shunt circuit is closed, whilst, on the
circuit of the main current being closed, the said armature is raised and thus
breaks the shunt circuit, substantially as described and shown.
Dated this 22nd day of August 1894.
WM. P. THOMPSON & Co.,
Agents.