ARTICULATED POWERED RAIL CARS FOR LOCAL TRAFFIC, IN PARTICULAR STREETCAR LINES

MATERIEL ROULANT ARTICULE CIRCULANT SUR RAILS EN MILIEU URBAIN, NOTAMMENT DES VOITURES DE TRAMWAY

English Abstract

ABSTRACT OF THE DISCLOSURE
The invention relates to an articulated streetcar train
of two or more rail cars, in which the bogies are attached below
each rail car centre in order to avoid having the bogies below
the articulation point. As a result all bogies may be of the
same type of construction. As second suspension between the car
bodies and the bogies there is a rubber or pneumatic shock
absorber, which is desired in such a way that it exerts
horizontal recuperating forces in order to deflect the car bodies
laterally in such a way that they follow the envelope curve when
travelling around a curve. This invention permits all the car
bodies to be designed as identical modules; the bogies may be
carrying and/or powered bogies, and the need for guidance means
for the car bodies is eliminated.

Claims

The embodiments of the invention in which an exclusive
property or privilege is claimed are defined as follows:
1. Articulated powered rail cars for local traffic, in
particular for streetcar lines, in which at least two car bodies
are movably connected by means of a linkage pivoting around a
vertical axis and each car body is mounted on a bogie,
characterized in that all of the bodies (3a to 3c) are attached
below the centres of the car bodies and all bogies are designed
in a form of construction that dispenses with a bogie cradle, in
that the bogies (3a to 3c) have a pneumatic or rubber shock
absorber as secondary suspension, and in that the car bodies (1a
to 1c) are manufactured in accordance with a modular design, and
wherein the first and the last rail cars (1a or 1c) are closed
beyond the module section by means of end sections (1d, 1e).
2. Articulated powered rail cars as per claim 1,
characterized in that all bogies (3a to 3c) are designed as
powered bogies in identical forms of construction.
3. Articulated powered rail cars as per claim 1,
characterized in that the bogies are designed as powered and
carrying bogies, and that each of the powered and carrying bogies
is identical in construction.
4. Articulated powered rail cars according to claim 1,
each of said car bodies having identically constructed central
modules.

Description

i7~
rhe invention concerns an articulated powered rail car
system for local -traffic, in particular for streetcar lines, in
which at least two car bodies are movably connected by means of a
linkage pivoting around a vertical axis, and the first and last
rail cars are each mounted on a bogie.
Articulated powered rail cars which are suppor-ted by
means of a bogies underneath the point of articulation are a
~nown design. The first and last cars are supported via end
bogies which are extended outward as far as possible in order to
limit the overhang when going around a curve. The middle bogies
are, as a rule, carrying bogies, in order to avoid the need for
complicated powered bogies, because there is not really enough
room for a power unit in the space available below the
articulation point. This situation is responsible for the
disadvantage that train units of greater length cannot be formed
~ecause, in such a case, the traction power of the end bodies
would not be sufficient for the job.
As opposed to this, it is the object of the invention
to improve on the design of articulated powered rail cars oE the
~o type discussed above in such a way that the forming of train
units can be readily carried ou-t without having to accept
excessive additional costs for procurement and maintenance.
This objective is fulfilled in accordance wi-th the
invention by the fact that all the bogies are attached below the
centres of the car bodies and all bogies are designed in a form
of construction that dispenses with a bogie cradle, in that the
bogies have a pneumatic or rubber shock absorber as secondary

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suspension, and in that the car bodies are manufactured in
accordance with a mo~ular design, whereby the first and last cars
are close~ oEf beyond the modular section by means of end
sections.
sy attachin~ all the bogies belo~ the centres of the
rail cars it becomes possible tC) provide all bogies with power
units so that long train units can be formed as well, if the need
arises, even when such trains have to overcome steeQ gradients,
since the whole weight of the train becomes available as
frictional weigh-t. Since all the bogies are equipped with
pneumatic or rubber shock absorbers as secondary suspension, any
lateral deflection or swivelling by the car bodies when going
around a curve is controlled by the recuperating forces of the
suspension itself, so that no special construction elements are
required for that purpose. By reason of the central location of
the bogies, the car body makes an optimal adjustment to envelope
curves when travelling around a curve. ~n addition, it is
possible for all the carrying or powered bogies to have a common
method of construction, by which means not only is manufacturing
made easier, but so is maintenance.
The same also applies to the car bodies, which can be
manufactured in module form, thus substantially reducing the cost
of manufacture, only the end rail cars being closed off by means
of supplementary sections. By using a method of construction for
the bogies which dispenses with bogie cradles, these bogies can
be designed with a lower structural height, so that the height of
the floors of the car bodies is less, and boarding the cars where
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ground-level railway platforms are involved is made easier.
An advantageous further improvement consists in the
fact that all the bogies are designed as powered bogies with
identical types of construction.
By reason of the fact that all the bogies are attached
at the centres of the rail cars, they can have the same type of
construction, thus not only making the cost of manufacture
substantially cheaper, but also making it possible to provide all
the bogies with power units. That measure enables even long
0 train units to overcome steep gradients, since the weight of the
whole train is made available as frictional force. Maintenance
is greatly facilitated because the sets of bogie wheels are
subject to uniform degrees of wear and tear, thus making it
possible to adhere to the same maintenance schedule for all the
bogies.
A further feature of the invention deserving special
~erit is the fact that the bogies are designed as both powered
and carrying bogies, and that each of the powered and carrying
bogies is designed in the same type of construction.
In the case of short units, by way of example those
having only two rail cars, or in the case of three or more rail
cars under normal rail-line conditions, it is possible to have
only the first and last bogies constructed as powered bogies, and
the remainder as carryin~ bogies. Since there is no bogie below
the articulation point, all the bogies can be designed in the
same type of construction. This results in making manufacturing
costs cheaper and in reducing maintenance costs, since spare

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parts inventory can be reduced.
An embodiment example of an ar-ticulated powered rail
car system according to the invention is illustrated in the
attached drawings, wherein:
Figure 1 is a side elevation of a train unit comprised
of two rail cars;
Figure 2 is a side ele~ation of a train unit comprised
of three rail cars; and
Figure 3 is a top sectional plan o~ a train unit with
three rail cars, showing how seats may be distributed and how
doors are arranged.
Detailed reference will now be made to the drawings
wherein like reference numerals identify like parts.
An articulated powered rail car system, in particular
for streetcar lines, having two rail cars, may be seen in Figure
1. The car bodies la and lb are joined together into a single
unit by means of an articulated linkage 2 in the centre. The
articulated linkage 2 allows for turning movements by the car
bodies la and lb around a vertical rotational axis. Deviating
from the otherwise normal method of construction, the car bodies
la and lb are each mounted at their centres on a carrying and/or
powered bogie 3a and 3b. These bogies 3a and 3b are designed in
a type of constructions which dispenses with bogie cradles, and
have a rubber or pneumatic shock absorber as secondary
suspension. By reason of attaching the bogies below the rail car
centre, it is possible to design all the bogies in the same type
of construction. This applies to both the carrying bogies and to

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the powered bogies. The latter do not need to take into account
the otherwise restricted space below the articulated linkage 2.
~he powered bogies therefore do not require any special type of
construction that is expensive and complicated, and for that
reason also often prone to breakdowns. By means of the
horizontal recuperating force of the secondary suspension, that
suspension controls the car bodies la and lb when going around a
curve. The centrally attached bogies lead to an optimal
adjustment of the car bodies la and lb to envelope curves, which
is also reflected in the highest possible utilization of space.
A train unit made up of three rail cars is shown in
Figure 2. Besides the car bodies la and lb shown in Figure 1, an
additional car body lc has been added as the middle rail car.
All the car bodies are alike in principle construction and are
constructed as modules. The car bodies la and lb deviate from
the module only due to the fact that they have a driver's station
ld or a car end closure le. ~he ~odule method of construction
not only makes the cars cheaper to manufacture, but also makes
tnem easier to maintain and to assemble into train units~ By
means of the better adjustment in the envelope curve the rail
cars need no longer be constricted at the front and at the rear
end of the train in the door areas, so that the available space
in these rail cars is greatly increased, and no wide gap e~ists
between -the door and the railway platform. In the version shown
with three car bodies la to lc, the two outer card bodies la and
lb can be supported via the power bogies 3a and 3b, while the
middle rail car lc can be supported via a carrying bogie 3c. I~

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it is operationally necessary, the bogie 3c can also be designed
as a powered bogie. Since it is not located below an articulated
linkage 2, the installation of a motor is not hindered by the
linkage or by a concertina passageway 4. The concertina
passageway 4 can be designed, in the simplest method, as an
all-encircling passageway, which achieves a reliable
maintenance-free, sealing-off of the articulated linkage. As can
be seen in Figure 3, the boarding entrances 5a to 5f can be
located outside the constricted sections of the car bodies la or
lb. This feature means that there is no large gap between the
edge of the railway platform and the door sill, and the movement
of passengers in and out can take place safely and
expeditiously. Over and above that, extra seating space is
obtained through having the constricted sections moved to the far
ends.

Representative Drawing