An Improved System of Current Supply for Electric Railways
Year: 1897

page_text: Date of Application, 17th Mar., 1897-Accepted, 11th Dec., 1897
"An Improved System of Current Supply for Electric Railways,"
I, ARTHUR PETZENBÜRGER of Gross-Lichterfelde, near Berlin, in the Empire of
Germany, 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 :-
This invention has for its object an underground electric current supply with contact
places above ground for railway vehicles of all kinds together with a protecting
device for the contacts and a taker off for the motor.
The invention will be described with reference to the accompanying drawings, in
which,
Figure 1 is a cross section of a double track railway;
Figure 2, a cross section of a multiple track railway;
Figure 3, a plan view of a double or multiple track railway;
Figure 4, a longitudinal section and elevation of a railway train and electric
locomotive;
Figures 5, 5B, 5° are details of a protecting device for the contact roller;
Figure 6 a b c are various sections of cable for different kinds of current ;
Figure 7 shows a rotating device for the contact roller.
Whilst in the systems of current supply for electrically operated railways hitherto
employed, each track required a separate non-insulated conductor or cable, this
invention renders it possible to obtain by means of a single insulated cable, the
working not only of single but of multiple track railways whereby in addition to
absolute security of working under all conditions of weather, an extremely cheap and
effective arrangement is obtained owing to the great simplicity of the system in
which any danger of short circuiting is avoided.
The current supply is distributed in Figures 14 in to the longitudinal
conductors (main conductors) laid beside the track and parallel thereto at
about 50 centimetres in depth, the cross conductors q in metallic connection with
the former and arranged at right angles thereto, and the standard conductors &
standing vertically to the latter, all the parts of the conductor being fully insulated
up to the contact rollers k and transmission brushes. It will be seen that a
two-sided utilization of the conductor is thus afforded, whereby two electric motors
may be run side by side in similar or opposite directions.
The system is characterised in general by the current supply taking place in the
following way:-
Single-sided or double-sided cross conductors q are arranged at distances of
about 50 metres at right angles or other suitable angle to the longitudinal conductor l,
to which cross conductors one, two or more standard conductors 8 are attached
according to the number of the tracks to be fed whereby one, two, or more motors
may be run side by side as aforesaid. The said standard conductors are exactly
arranged in the middle of each rail track and project about 15 centimetres from the
bed inclusive of the contact roller above the upper edge of the rails. The current
taker is in the form of one or (according to the kind of current) more naked metal

page_text: wires arranged exactly in the centre under the locomotive and about six carriages,
that is to say suspended for a total length of over 50 metres in such a way that
during the journey, the whole length of the current taker travels over the contact
rollers and each engages a second roller before running off the first.
The current is permanently conveyed to the motor in this certain and simple
manner and the whole system is a reversal of the above-ground current supply
system hitherto found the best, the difference being that in the present case, the
part conductor, that is to say the current taker moves forward whilst the rollers are
fixed in their places.
As the total length of the ordinary passenger trains amounts all through to more
than 55 metres and the current taker exten is from the buffer plate of the locomotive
to the buffer of the sixth or last carriage, about 50 metres is found to be a suitable
distance apart for the contact rollers from one another, it being assumed that in the
case of goods wagons, the locomotive is couple as closely as possible with the
first six wagons in order to avoid a multiple separation and connection of the current
taker.
For the shunting of the locomotive when travelling loose, an accumulator is
provided thereon, or the distance apart of the contact rollers at stations, shunting
sidings, etcetera, may be reduced to about 6 metres according to the minimum length
of the locomotive.
As regards the construction of the separate conductor parts, it must be remarked
that the long conductor may be formed of one or more conducting wires (see
Figures 6A BC) arranged insulated from one another in the form of a cable which
affords the possibility of feeding one and the same motor in combination with
suitable commutator devices alternately with different kinds of current, such as
continuous current, alternating current, or multiphase current. Thus for instance
with triphase current, three rollers, as shown in dotted lines in Figure 1, must be
arranged instead of one. The use of various kinds of current may also be easily
effected by attaching the standard conductors and the cross conductors belonging
thereto alternately to the wires of the different kind of current so that on each
50 metres length alternately, different kinds of current "ome into action. It must
here be added that within the insulated cross conductors and standard conductors a
feed and return wire (that is to say a return circuit) is provided, which is fed from
the main conductor or from the accumulators herein after described.
The standard conductors 8, the upper ends of which are the sole visible parts of the
whole current supply, branch up vertically from the cross conductors. They have
each at their upper end a fork in which a pin is fixed on which again a contact roller
is freely revoluble (several such rollers may also be employed according to the kind of
current) with both a forward and backward movement. This roller is set in motion
either directly by the current taker or in order to avoid wear and tear as far as
possible may be provided with an electric driving gear of its own, see Figure 7, which
is switched on and off automatically by the train and is only in action whilst being
travelled over. In single track railways or in stations or the like, a reversing device
is provided to enable the roller to rotate in either direction which however is hardly
necessary in double and multiple tracks for the eventual return journeys.
The means for switching on and off the electric driving gear of the contact roller
is shown in Figure 5^ where it is assumed to be in combination with a protective
device consisting of a light, internally insulated metal sleeve c and a metal cover d
which is connected thereto by means of a hinge. A roller is revolubly mounted on
the sleeve c and the latter placed over a hollow post h having in its interior a
spring which tends to press the sleeve e normally to the top of the post h.
2"
The protective device fully encloses the head of the hollow post h or stand
conductor, that is to say the contact roller k together with the fork, brushes and the
like, when not in use, see Figures 5 and 5º. A curved or inclined rail g¹ is fixed
edgewise along the locomotive and the first six vehicles on both sides of the current
taker in such a way that according to the direction of travel, one of the rails will
encounter the roller r, Figure 5º, and press it down together with the sleeve c, thus

page_text: causing the cover d to open so that the contact roller k is free for the current taker
(Figure 5). Contact is simultaneously closed with the electric motor (Figure 7) by
means of a pin a standing in com'nunication with the conducting wire, by means of
rubbing contact springs ff, so that the contact roller k is at once set in rotation and
the current taking wire slides easily over it, whilst as soon as the pressure rail g¹ has
run off the roller 7, the spring f contained in the hollow post h again lifts the sleeve c
so that the cover d which is provided with an insulating plate, again closes by its
own weight and protects the contact roller from contact and moisture. A
counterweight may be employed instead of the spring f2.
The accumulators w shown in Figures 1, and 3 have for their object to accumulate
a certain supply of current along the whole stretch of the railway, as in some cases
the sources of current are situated at great distances, causing great differences of
electro-motive force, and it is possible to obtain with moderate but long-continued
deliveries of power, for instance by means of water power, a manifold and even
accumulation of current over large stretches and to equalize by the insertion of
the accumulators the difference in the demands or requirements which fluctuate from
time to time.
These accumulators w may either be attached to each standard conductor s or to a
larger extent and at wider distances apart to some of the cross conductors q, as is
shown in Figures 1, and 3. The long-continued current supply in the main
conductor is transmitted to and stored up by the accumulators, and yielded up by
them through the contact k to passing trains.
In conclusion it may be stated that in addition to the extraordinary advantages of
this system of current supply which easily and fully suffices for all the requirements
of railway working under all conditions of weather, there must be added that without
any special construction, curves, inclinations, points, bridges and the like may be
easily overcome and also great net-works of tracks in goods and shunting-stations
may be easily and cheaply supplied with current.
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. A system of current supply for electric railways characterised by the two-sided
utilization of a current conductor by means of two electric motors travelling side
by side in similar or opposite directions, substantially as herein before set forth.
2. In the hereindescribed system of current supply for electric railways, the use of
a cross conductor that is to say a conductor arranged at any suitable angle to the
main conductor on one or both sides opposite or otherwise, in combination with
standard conductors for one, two, or more electric motors travelling side by side in
similar or opposite directions, substantially as described.
3. In the hereindescribed system of current supply for electric railways, the
arrangement of a subterranean and overground supply, characterised by the conductor
being subterranean, whilst the contact rollers, points of contact or current delivering
places are above ground and work without the use of magnets, substantially as
described.
4. In the herein described system of current supply for electric railways, a stand
conductor which projects above the ground (ballast) and the sleepers and allows of the
use of an electric motor without the employment of magnets, substantially as
described.
5. In the herein described system of current supply for electric railways a current
taker (slide rail, contact rail) which extends beyond the length of a single vehicle,
substantially as described.
6. In the herein described system of current supply for electric railways, the
use of rollers on the contact places of the current conductors for the purpose of
conveying current to the current taker connected therewith, substantially as
described.
7. In the herein described system of current supply for electric railways, the

page_text: driving of electric railways by means of fixed accumulators arranged on standard
conductors or cross-conductors and placed in communication with current conductors,
substantially as described.
8. In the herein described system of current supply for electric railways, the
protective device (Figures 5A 5B 5C) characterised by the same being adapted to be
switched off by the moving motor car and again automatically switched on by a
spring () substantially as described and illustrated.
9. In the herein described system of current supply for electric railways, the use
of different kinds of current, such as continuous alternating or multiphase currents,
with a single conductor provided with several branches substantially as described.
10. In the herein described system of current supply for electric railways a contact
roller adapted to be automatically constantly set in rotation by means of an internally
mounted electric motor, substantially as described.
Dated this 16th day of March 1896.
WM. P. THOMPSON & Co.,
Of 6 Lord Street Liverpool, Agents for the Applicant.