Railway vehicle spring assembly

A springing system for a rail vehicle having a frame and a wheel bearing, has two substantially vertical spring elements connectable with the frame or the wheel bearing and located at both sides of the latter, two resiliently yieldable bushings each connected with the respective spring element and located between the latter and the wheel bearing or the frame, respectively, and two resiliently yieldable intermediate elements each located intermediate one of the bushings and the wheel bearing or the frame, respectively. Each of the bushings together with the respective intermediate element forms a stop for absorbing a longitudinal force which is produced during acceleration or deceleration of the veicle. The springing system also provides for a radial adjustment of the wheels of the vehicle under the action of a friction force between the wheels and the rails when the vehicle moves along a curved path.

BACKGROUND OF THE INVENTION 
The present invention relates to a springing system for a rail vehicle. 
More particularly, it relates to such a springing system of a rail vehicle 
which includes vertical spring elements. 
Springing systems for rail vehicles have been proposed in the art, each 
including two vertical spring elements located at both sides of a wheel 
bearing of the vehicle, as considered in the longitudinal direction of the 
latter. Each of such spring members includes a bell-shaped housing, a 
resiliently yieldable ring located in the housing, and a conical pin 
insertable into the resiliently yieldable ring. Such springing system 
offers the required resistance to vertical shocks and also satisfies the 
requirements of low wear. However, this system does not provide to a 
sufficient extent for a soft and shock-less transmission of longitudinal 
and transverse forces which are of an important nature in rail vehicles 
(for the comfort of the passengers or for the safety of delicate cargo). 
Furthermore, since wheels of the rail vehicle must be adjusted radially 
relative to the center of a curve when the rail vehicle moves along a 
curved path, the springing system must be so located that a relatively 
small friction force between the wheels and the rails produces the above 
adjustment of the wheels. Moreover, it is desirable to avoid an 
excessively high relative movement between the wheels and a rotational 
frame or an underframe of the rail vehicle when increased longitudinal 
forces are produced during acceleration or deceleration of the vehicle, 
such as those produced during starting or braking of the vehicle. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of the present invention to provide a 
springing system for a rail vehicle, which avoids the disadvantages of the 
prior art springing systems. 
More particularly, it is an object of the present invention to provide a 
springing system for a rail vehicle, which not only offers requisite 
resistance to vertical forces applied to the vehicle, but also satisfies 
the requirements made with respect to the transmission of longitudinal and 
transverse forces applied to the rail vehicle. 
Another feature of the present invention is to provide a springing system 
for a rail vehicle which is so constructed that, on the one hand, it 
provides for a radial adjustment of the wheels under the action of a 
friction force between the wheels and the rails when the vehicle moves 
along a curved path and, on the other hand, substantially directly 
transmits a longitudinal force which is produced during acceleration and 
deceleration of the vehicle. 
In keeping with these objects, and with others which will become apparent 
hereinafter, one feature of the present invention resides, briefly stated, 
in a springing system for a vehicle having a frame and a wheel bearing, 
which system has two substantially vertical spring elements located 
between the frame or the wheel bearing and at both sides of the latter, 
two resiliently yieldable bushings each connected with the respective 
spring element and located between the latter and the wheel bearing or the 
frame, respectively, and two resiliently yieldable intermediate elements 
each located intermediate one of the bushings and the wheel bearing or the 
frame, respectively. Each of the bushings together with the respective 
intermediate element forms a stop for absorbing a longitudinal force which 
is produced during acceleration or deceleration of the vehicle. This stop 
may be formed with play or, in the case of a free-from-play construction, 
can create a desirable spring-force/spring displacement characteristic for 
the arrangement. 
Each spring element may be comprised of a rigid bell-shaped housing, a 
resiliently yieldable ring located in the housing, and a conical pin which 
is insertable into the ring. The bushings may be compound rubber-metal 
bushings, and the intermediate elements may be constituted of rubber. 
The springing system for the wheel bearing in accordance with the 
invention, has great yieldability in horizontal direction, so that 
longitudinal and transverse forces are softly and shock-lessly transmitted 
by the system to the vehicle. At the same time the springing system is 
substantially wear-free and is not subject to contamination. For the above 
reasons, the springing system has a practically constant characteristic of 
resilience during its entire service life. Given the particular 
characteristics of a rubber material of the respective parts of the 
springing system, the vertical resilience of the springing system depends 
upon the vertical interval between the resiliently yieldable rings of the 
spring members and the bushings; further, the resilience of the springing 
system in the transverse direction depends upon the width of the bushings, 
and in the longitudinal direction it depends upon the above-mentioned 
stop. Since the construction provides for radial adjustment of the wheels 
and is stabilized with respect to the forces which are produced during 
acceleration and deceleration of the vehicle, the springing system in 
accordance with the present invention satisfies the requirements made with 
respect to the rail vehicle. 
Another feature of the present invention is that each pin is connected with 
one of the chassis elements and formed as an angle lever having two arms, 
one of which arms is connected to one of the chassis elements, whereas the 
other arm carries the resiliently yieldable intermediate element. This 
construction provides for an especially economical accommodation of the 
intermediate elements and easy mounting thereof. Because the forces which 
are produced during acceleration or deceleration of the vehicle are 
directed opposite to one another, and, moreover, the rail vehicle moves in 
two opposite directions, it is understood that the above stop must be 
doubled or symmetrically located with respect to a vertical middle plane 
of the wheel bearing. 
Still another feature of the present invention is that each intermediate 
element is located between the other arm of the angle lever and the other 
chassis element under pre-stress. This creates such a spring force/spring 
displacement characteristic curve for the arrangement as a whole, that the 
influence of relatively small disturbing forces resulting from ordinary 
wheel travel will be suppressed. 
An additional feature of the present invention is that the bushing is 
adjustably connected with the other chassis element, such as by a shaft, 
which latter is received in the bushing for joint rotation therewith and 
engaged with a lever which, in turn, connects the shaft with the other 
chassis element through an eccentric device. This construction provides 
for a simple and easy adjustment of the wheels parallel to one another 
during mounting of the springing. 
The novel features which are considered as characteristic for the invention 
are set forth in particular in the appended claims. The invention itself, 
however, both as to its construction and its method of operation, together 
with additional objects and advantages thereof, will be best understood 
from the following description of specific embodiments when read in 
connection with the accompanying drawings.

DESCRIPTION OF PREFERRED EMBODIMENTS 
A springing system for an axle bearing of a rail vehicle in accordance with 
the present invention, has two spring elements which are identified in 
toto by reference numeral 1 and are located at both sides of a vertical 
middle plane of the wheel bearing 5 of the vehicle, as shown in FIG. 1. 
Each spring element 1 includes a bell-shaped housing 2, a resiliently 
yieldable ring 3 located in the housing 2, and a pin 1' insertable into an 
inner hole of the ring 3. The housing 2 of each of the spring elements 1 
is mounted on a frame 6 of a chassis of the vehicle by mounting screws 11, 
as shown in FIG. 1. 
Each pin 1' has a conical portion 1b by which it can be inserted in the 
inner hole of the ring 3, and a middle portion which is spaced from the 
conical portion 1b. A rubber metallic bushing 4 is mounted in the above 
middle portion of pin 1'. The bushing 4 is resiliently rotatable in the 
longitudinal direction of the vehicle and therefore is adapted to transmit 
a force. An inner portion 4a of each of the bushings 4 is braced in a 
fork-shaped portion of the wheel bearing 5 by a screw 12 and a thrust ring 
13, as shown in FIG. 3. The inner portion 4a is further connected with a 
shaft 8 by a key 14. The shaft 8 carries a lever 10 which is adjustably 
held on the wheel bearing 5 by an eccentric arrangement 9, as shown in 
FIG. 2. By an adjustment of both levers 10 the wheel bearing 5 can be 
moved in the longitudinal direction of the vehicle. In this manner, all 
the wheels of the vehicle can be adjusted parallel to each other so as to 
compensate for permissible tolerance deviations of the frame construction. 
As particularly shown in FIG. 1, the pin 1' is formed as an angle lever. 
The conical portion 1b of the angle lever is located at one side of the 
bushing 4, whereas a second portion or arm 1a of the angle lever is 
located at the other side of the bushing 4 and carries a resiliently 
yieldable rubber element 7. The rubber element 7 abuts against the wheel 
bearing 5. The rubber element 7 is comprised of two elastic layers 7a and 
7b, and its resilient characteristics can be adjusted by a tightening 
screw 15. A casing 16 of the rubber element 7 partially surrounds the 
latter and limits, in connection with the wheel bearing 5, a resilient 
yielding of the entire arrangement in the case of an increased 
deceleration force. When it is desirable for running tests to "switch off" 
the action of the rubber element 7, this can easily be done by positioning 
a rigid member between the arm 1a and the wheel bearing 5. 
In the springing system, in accordance with the present invention, the 
resiliently yieldable bushings 4 provide for an adjustment of the wheels 
of the vehicle under the action of a friction force between the wheels and 
the rails, when the vehicle moves along a curved path, whereas the rubber 
element 7 provide for substantially direct transmission of a longitudinal 
force which is produced during acceleration or deceleration of the 
vehicle, such as during starting or braking thereof. 
FIGS. 4-8 show other embodiments of the present invention. The parts of the 
springing system shown in these Figures, which are identical to those 
shown in FIGS. 1-3, are identified by identical reference numerals. 
As shown in FIG. 4, the pin 1' of the spring member 1 may be fixedly 
connected with the frame 6 of the chassis of the vehicle. The housing 2 of 
the spring member 1 is articulately connected with the wheel bearing 5 
through the bushings 4 and the rubber element 7. The lever is formed by 
the housing 2 and the arm 1a. 
In accordance with an embodiment shown in FIG. 5, the housing 2 of the 
spring member 1 is fixedly connected with the wheel bearing 5, whereas the 
pin 1' thereof is articulately connected with the frame 6 of the chassis 
of the vehicle through the bushing 4 and the rubber element 7. 
FIG. 6 shows still a further embodiment in accordance with which the 
housing 2 of the spring member 1 is movably mounted on the frame 6 of the 
chassis of the vehicle through the bushing 4 and the outer element 7. The 
bushing 4 is supported by consoles 17. The pin 1' is fixedly connected 
with the wheel bearing 5. The lever is formed by the housing 2 and the 
portion 1a. 
Still one embodiment is shown in FIG. 7, wherein the bushing 4 is held by 
the two consoles 17 on the frame 6 of the chassis of the vehicle. The 
housing 2 of the spring member 1 is connected with the wheel bearing 5, 
whereas the pin 1' is oppositely conical, as compared with that shown in 
the previous Figures, and is articulately connected with the consoles 17 
of the frame 6 through the bushing 4 and the rubber element 7. 
In all the above constructions only one of the rubber elements 7 is 
operative for stabilizing of the arrangement in a certain direction of 
travel. In an embodiment shown in FIG. 8, a double construction is 
presented, in which both rubber elements 7 are fixedly connected with the 
arm 1a of the pin 1', such as by suitable adhesive known per se. 
It will be understood that each of the elements described above, or two or 
more together, may also find a useful application in other types of 
constructions differing from the types described above. 
While the invention has been illustrated and described as embodied in a 
springing system for a rail vehicle, it is not intended to be limited to 
the details shown, since various modifications and structural changes may 
be made without departing in any way from the spirit of the present 
invention. 
Without further analysis, the foregoing will so fully reveal the gist of 
the present invention that others can, by applying current knowledge, 
readily adapt it for various applications without omitting features that, 
from the standpoint of prior art, fairly constitute essential 
characteristics of the generic or specific aspects of this invention.