Improvements relating to Electric Railways and Tramways provided with Sectional Conductors or Surface Contacts.
Year: 1898

page_text: Date of Application, 4th Nov., 1898-Accepted, 15th July,
1899
Improvements relating to Electric Railways and Tramways provided
with Sectional Conductors or Surface Contacts.
I, JASPER WETTER, Patent Agent, of 37 and 39, Essex Street, Strand, in the
County of London, do hereby declare the nature of this invention, a communica-
tion from abroad by the Elektrizitäts-Aktiengesellschaft vormals Schuckert & Co.,
Electrical Engineers, of Nürnberg, Bavaria, to be particularly described and
ascertained in and by the following statement:-
This invention relates to electric railways and tramways with underground
conductors and surface contacts, in which the different sections or contact studs
are automatically and consecutively connected with the main conductor or feeder
by means of a switching device operated by the motor carriage.
In the accompanying drawings, Fig. 1 is a diagram of the entire arrangement;
Fig. 2 shows a special arrangement or construction of the skate secured to the
motor carriage; Fig. 3 shows a part of a switching apparatus on a larger scale.
As shown by Fig. 1, each switching apparatus comprises the following principal
parts, viz.
1, an electromagnet a and an oscillating armature b connected with the con-
tact lever c.
2, a withdrawing device, which replaces the contact lever into its position of
rest, as soon as the skate attached to the carriage has reached the next contact pin
or sectional conductor (in the direction in which the carriage moves). The with-
drawing device is composed of an electro-magnet d, an armature f mounted on
the axle of the armature b, and a contact lever g for short-circuiting the winding
of the electro-magnet a.
3, a double relay h having an armature i adapted to make contact either on one
side or on the other according to the direction in which the carriage moves.
4, a resistance k.
The windings of the contact devices are all placed in a separate circuit, which
is a shunt of the feeder main and serves for turning and maintaining the contact
levers.
To explain the working of the new system of current supply, Fig. 1 assumes,
that the motor carriage stands on the contact stud or sectional conductor 4 ready
for starting, and that the latter carries no current, as is actually the case at the
time of starting.
In order to establish an electric current between the skater situated under the
carriage, and the sectional conductor 4, a battery of accumulators mounted in
the carriage is joined at one pole with the earth, or with the return rail, and at
the other pole with the skate. The battery current will then flow from the
surface contact stud 4, through the windings of the electro magnet a₁ of the con-
tact apparatus, to the armature of the corresponding relay h. As the contact
Jevers of the latter rest against the stationary contacts on both sides, the

page_text: current will be divided, one branch flowing to the lower right hand coil of the
relay h, and the other to the lower left-hand coil of the relay h, of the switching
apparatus 5, the levers of the relays h, and he will therefore occupy the positions
indicated in the drawing, and the contacts 3 and 7 of the relays 3 and h, will
be broken on one side. The carriage may now start either to the right or to the
left in the manner hereafter described.
From the lower right hand coil of the relay the current flows to the upper
right hand coil of the relay h, and thence through the drawing-off coil of the
electro-magnet d of the apparatus 5 to the corresponding resistance coil k, and
thence to earth.
In the same manner the current flows from the lower left hand relay coil of the
switching apparatus 5 to the upper left hand coil of the relay 4, thence through
the drawing-off coil of the electro-magnet da, to the corresponding resistance and
thence to earth. Consequently two forces are acting on the armature of the
relay in the two upper coils, which forces keep each other in equilibrium and
cannot set the armature in motion.
The electro-magnet a excited by the battery current causes the contact
lever €49
which is rigidly connected with the armature b, to turn, and thereby to
switch the feeder s into the circuit of the carriage motor, so that the carriage
may run either in one direction or the other.
Supposing, for example, that the carriage runs to the left, and that con-
sequently the skate touches the contact stud 3, (as indicated by dotted lines) the
current will flow through the same and the windings a to the right hand con-
tact of the relay h, and thence through coils h, and h, to the drawing-off coil
so as to operate the drawing-off apparatus before the skate has left the contact
stud 4, because the length of the skate is greater than the distance between two
consecutive surface contacts. During this operation the drawing-off apparatus,
shown by Fig. 3, acts by attracting the lever f4, so as to make contact between
the contact plate of the short circuiting arm g (which is insulated from the said
arm) and the contact plate e of the lever 4, and form a path from the point
through arm, and armature b. to point y, whereby the magnet winding a is
short-circuited and currentless, after which the lever which had closed the
circuit, returns to its position of rest, represented by dotted lines.
By this operation the feeders is switched off the sectional conductor 4, and no
current can flow through the same, after the carriage has passed.
The short-circuiting device has the effect, that the coils of the electro-magnet a
are already without current, before the contact lever is drawn off.
When the carriage moves in the direction mentioned above, the relay h is
already so adjusted, that it draws the armature of the relay he also to the right,
so soon as the skate touches the contact stud 3 and sends current into the shunt
winding of the corresponding switching apparatus. The upper coil of the
relay has the effect, that the armature of the latter remains in the position
imparted to it by the preceding relay 4, even after the skate has left the contact
stud 4 and thereby broken the circuit, in which the lower right hand winding of
the relay his situated.
For the run of the carriage from the contact stud 4 to the right towards the
contact stud 5, the course of the current is analogous.
After the first contact stud or sectional conductor has been placed in circuit by
means of the battery of accumulators, the latter can be switched off again.
To prevent the possibility, that at the first starting two consecutive contact
studs, which, owing to the great length of the skate, may happen to touch the
same at the same time, should receive current from the accumulator at
the same time, the skate is preferably composed of two parts, as illus-
trated by Fig. 2, so that according to the direction in which the carriage moves.
either one or the other half of the skate will be connected with the battery of
accumulators. After the first contact has been established, the two halves of the
skate are again electrically connected,

page_text: 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. In electric railways and tramways having underground conductors and sur-
face contacts or sectional conductors, each of which is combined with a shunt
electro-magnet for operating the circuit-closing armature, the means or system
for regulating the distribution of electric current, chiefly comprising a double
relay placed in series with the said electro-magnet and having an armature
adapted to be excited by a separate source of current at the first starting of the
carriage, and by the shunt of the main current during the motion of the carriage,
and thereby to excite the relays of the immediately preceding and immediately
following contact stud or sectional conductor, in order to switch off the imme-
diately preceding contact stud after the carriage has passed, by means of a device
for short-circuiting the electro-magnet of the switching apparatus, and at the
same time to operate the relay armature of a succeeding contact stud, in such a
manner, that the switching apparatus belonging to the latter will be set according
to the direction of motion, substantially as described.
2. A system of current distribution for electric railways and tramways pro-
vided with underground conductors and surface contacts, having the characteristic
feature, that the withdrawing electro-magnet (7) belonging to a contact stud and
excited by a preceding relay, co-operates with the armature (f) actuated by the
principal electro-magnet (a) and with a short-circuiting contact (g) in such a
manner, that the circuit closing lever c is drawn back into its position of rest
by means of the contact g, as soon as the skate (r) of the motor car has reached
the contact pin situated in front of it-in the direction the carriage runs-and
belonging to the relay (h), or as soon as this relay has been caused to excite the
withdrawing electro-magnet included in its circuit, substantially as described.
3. The herein before described devices forming part of a system of current
distribution for electric railways or tramways with underground conductors and
surface contacts.
Dated this 4th day of Navramban 1800

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