An Improved System of Conductors for Electric Railways.
Year: 1897

page_text: Date of Application, 21st May, 1897-Accepted, 26th June, 1897
An Improved System of Conductors for Electric Railways.
1, EDUARD LACHMANN, of 66-68 Alter Wall, Hamburg, in the Empire of
Germany, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertaine
in and by the following statement :-
This improvement relates to a conductor (or system of conductors) of electrical
current of different classes or qualities, as applied to the operation of electrical
railways; wherein the current-receivers or contacts are arranged, not side by side,
but behind one another and so as to come into operation alternately, the carriage-
motor being fed from any suitable number of such receivers, without any
interruption of the circuit.
The accompanying drawings represent by way of example, diagrams of one form
of such a system of conductors, arranged for the operation of an overground
electrical railway.
The two outer conductors, differing in polarity or phase, may be said to be
divided into partial working conductors, or sections, the arrangement being such
that a section of one of the conductors extends alternately below and above a
section of the other conductor; and the effect being the formation of one single
working conductor for the current-receivers to travel along; such conductor
consisting of a number of sections placed in succession behind each other and
alternating in polarity or phase.
In the example shown, three roof or trolley arms c¹, c², c³, each fitted with a
contact-1oller at the top, are supposed to be arranged upon the carriage behind
one another, in such a manner that, while they slide along three succeeding
conductor-sections, they are, on the other hand, electrically connected, either each
with a separate pole-inverter cr commutator, d', d² and d³, respectively, as shown
in Figure 1, or all with one combined commutator, as illustrated in Figure 2.
Each of the commutators, as represented in Figure 1, has two contact
surfaces, el and e², one of which is connected with the positive pole, and the other,
with the negative pole, of the inner carriage-motor conductor L, which, in its
turn, is connected with the source or generator of electricity E in the well known
manner; while the positive overhead conductor A is connected to the positive pole
of the said source of electricity, and the negative conductor B, to the negative
pole of such source.
When the carriage or car is in motion, each commutator, alternately, so adjusts
itself, that its corresponding current-receiver becomes connected either with the
positive, or with the positive contact surface, e' or e², respectively, or with neither,
according as it happens to slide along the positive or negative overhead conductor,
or neither. Hence-as will be readily seen by reference to Figure 1-there forms
a closed circuit between the external and internal conductors.
Three current receivers are provided, so that, whenever one such receiver
passes, free from current, from one conductor-section to the next, there may still
remain two receivers in contact with two sections of different polarity, whereby an
interruption of the circuit is avoided.
Instead of employing currents of different polarity, alternating currents of
different phase may be used; and the number of such different currents need not
be confined to two, but three or more different currents may be utilized; in which
case four or a greater number of current-receivers instead of three-should be

page_text: provided; and such heterogeneous currents may then be all simultaneously
conveyed to a rotary current or other motor located on the vehicle.
.;
"
The several sections of the working conductor, arranged one behind the other,
properly insulated, and traversed alternately by currents of different kinds, in
reality form but one single-line conductor a b² a³ 64 and side by side with
this bare conductor there may be arranged the sections 61 a² 63 14.
which are
not touched by the current-receivers, but merely serve as current-feeders; they
being placed against the working sections proper with the interposition of suitable
means of insulation; so that, unlike the usual arrangement of a number of blank
conductors, extending in juxtaposition, from each of which current of a different
nature is collected, the improved system is designed to minimise the losses or waste
of current, whilst requiring less space i.e. a reduced sectional area for the location
of the conductors, thus affording an important advantage for underground current
supply. At the same time, the insulated current-feeding sections ba² b³ a².
may, in the case of overground conductors, serve as a protective covering for the
bare sections a¹ 12 a³ 64 . . .
The combined commutator or converter mentioned above, and shown at U,
comprises as many electro-magnets m¹ m² m³ as there are current receivers c'
These magnets are connected into a circuits in series. Over each
magnet there are suspended from a beam wa pair of iron cores R R, on which is
wound in series the conductor leading from a current receiver or contact
arm, c¹, c², c³, respectively. Each beam w is adapted to swing between four
circuit-closing surfaces fƒƒ¹ƒ, two of which are connected with the conductor /
of the current-receiver, while the two remaining surfaces are connected to the
direct motor conductor.
This is at
The operation of this converter or commutator will be readily understood.
The current-receivers, which are supplied with current at the time-say cl
and c²-magnetism is generated in the iron cores k k of their wire l.
first assisted by the coil p disposed for a powerful resistance and fitted with an
earth connection. One core is accordingly attracted by one pole of the electro-
magnet, while the second core is repelled by the other pole; with the result that
the oscillating beam w is so swung round that it connects electrically two of the
circuit-closing surfaces ff', so that the receiver-current is enabled to flow to the
carriage-motor.
Inasmuch as the currents supplied to the cores kk by the current-receivers
continually change their polarity or phase, the one or the other core k of each
converter is attracted or repelled by the electro-magnet m alternately, and,
accordingly, the current supplied from the receiver is sent into the positive motor-
conductor at one time, and into the negative motor-conductor at another, according
to its polarity.
'
Whilst a receiver passes underneath a junction between any two of the conductor-
sections a¹² a³b, the corresponding pair of iron cores receive no current, they
being kept at an equal distance away from the electro-magnet by springs such
as v v. In this position of the cores, the beam w will be situated between the two
surfaces ff and does not connect either with any one of the pair of surfaces f¹¹
of the motor-conductor.
Where alternating or rotary currents are employed, no such converter or
commutator is necessary, the several current receivers being in that case adapted
to be put in connection with the several pole-posts or screws of the motor.
arrangement such as this, neither are the magnets & demagnetized, nor is the
direction of rotation of the motor reversed.
In an
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
--
For the purpose of supplying electrical railway systems with current of various
categories

page_text: (1.) A working conductor consisting of sections arranged one behind the other
and traversed in alternating succession by different sorts of current, and conveying
the various sorts of current to the motor through a suitable number of current
receivers without any interruption of the circuit.
(2.) In combination with a conductor such as is referred to in the 1st claim, two
or a greater number of current receivers, corresponding to the number of currents
of different kinds used, arranged in such a relation to a series of automatic pole-
inverters, that one receiver may supply, in immediate or uninterrupted succession,
positive and negative continuous currents.
JYJ
1007
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.