LATERAL CONTROL MOUNT
BACKGROUND OF THE INVENTION
This invention relates generally to suspension mountings, and more
particularly, to mounting for the steering system of a railway truck.
Mountings with load suspension and vibration-dampening capabilities have
been used in the past to improve the steering and ride characteristics of railway
trucks. A typical railway truck includes two side frames connecting front and rear
wheelsels mounted on axles. The side frames are connected by a cross-member or
bolster and p:ovide the railway truck with a stiff structure for mounting a railway
car for ca: rying cargo. An elaslomeric mounting, which is a mounting that includes
a pad of an elastic material like rubber or another elaslomeric material, is typically
positioned between an axle bearing adapter and the side frame adjacent to each
wheel to support the frame and car on the axle. The elaslomeric mountings permit
the ax'es of the railway car to move horizontally with respect lo the side frames lo
allow the axles lo turn or follow the rail curvature. Additionally, the elaslomeric
mountings support vertical static and dynamic loads, such as the weight of the frame
and cargo in the car. This type of suspension is typically utilized in, for example,
radial self-steering and non-radial railway trucks. By allowing the axles to turn with
respect to the railway truck, the elaslomeric mountings reduce the friction between
the wheels and the rail, thereby improving their life. Additionally, the reduced
friction make-; the railway truck easier to pull, thereby increasing fuel economy for
the train locomotive.
The railway truck may experience ride control problems when using typical
elaslomeric mountings, however, due lo the mountings' lack of conrol over lateral
horizontal motion independent of longitudinal horizontal motion. for example,
lateral motion of the axles with respect lo the side frames can contribute to stability
of me railway truck at high speeds, which produces poor ride characteristics. Since
the elastomeric pad of a typical elastomeric mounling is generally flat in the
horizontal plane, the lateral spring rale typically is about equal to the longitudinal
spring rate. As such, it is generally not desirable to increase the lateral spring rate of
the flat elastomeric pad, because this will result in the longitudinal spring rale being
correspondingly increased, negatively affecting the steering characteristics of the
railway truck.
In order to increase the lateral spring rale independent of the longitudinal
spring rale, some elastomeric mountings have included alternating layers of
elastomeric pads and rigid shims having a V-shaped, or inverted V-shaped, cross-
section. The V-shaped cross-section is in a plane parallel to the axles, or
perpendicular to the side frames. For instance, one such elastomeric mounling is
described in U.S. Patent No. 3,699,897 Jo Sherrick, issued October 2-1, 1972 and
assigned to the assignee of the present invention. The V-shaped cross-section
provides a laterally-inclined surface that increases the lateral spring rate of the
mount, but does not affect the longitudinal spring rale. Also, the V-shape of the
rigid shim, for example, serves to contain the lateral movement of the elastomeric
pad, reducing the amount of pure shear and increasing lateral compression within
the elastomeric pad, thereby increasing the lateral spring rate. Similar mounts have
used other curved cross-sectional shapes, as well as flanges, to restrain the lateral
motion of the mount.
These solutions have had limited success in increasing the lateral spring rate,
however, because the angle of the inclined V-shaped cross-seclion is limited by the
allowed space for the mount. In many cases, elastomeric mountings are required lo
adapt lo, improve or be retrofit into existing railway trucks. As a result, the
available space for the mount may lie limited to the space occupied by I he existing
mount. This available space generally cannot be increased, lor example, due lo
railway truck height limitations for going under bridges and through turnels, and
l\uc lo coupler height limitations lo permit adjacent railway trucks lo be copled
together. In many cases, this available space does not allow a sufficiently inclined V-
shaped section to provide a desired lateral spring rale. Thus, since the spring rate of
the elaslomeric pad cannot be increased without unwelcome changes to the
longitudinal spring rate, a less than optimal solution is provided by mountings
having V-shaped or other curved-shaped cross-sections.
SUMMARY OF THE INVENTION
In order to overcome the drawbacks of the prior art, a mount for use between
a side frame member and a bearing adapter in the suspension system of a railway
truck has been developed that lias a dramatically-increased lateral spring rale. In
one embodiment, a mount includes a rigid material layer having at least four
sections laterally angled between a horizontal axis and a vertical axis, and at least
two of the a! leasl four sections being oriented parallel to a different axis than the
other two. A first and second elastic material layer are positioned, respectively,
between the side frame member and rigid material layer and the rigid material layer
and bearing adapter. Also, the first and second elastic material layers each have at
least four sections abutting and conforming to ihe at least four sections of the rigid
material layer. Kach of the first and second elastic material layers, as well as the
rigid material layer, have a thickness and angular orientation selected lo result in the
lateral horizontal spring rate having a- compression component a<>d a shear
component, and wherein the compression component is greater than the shear
component. Thus, the angled sections cooperate to dramatically increase the
horizontal lateral spring rate of the mount without increasing the horizontal
longitudinal spring rale, thereby improving ihe ride characteristics and high speed
stability of the railway truck.
The mount' may (further include)^ lop plate and bottom plate respectively in
contact with the first and second elastic material layers for adapting the mount to the
side frame member and bearing adapter, respectively. Preferably, the top plate has a
bottom surface with at least four sections tbat correspond with and are parallel to the
at least four sections of the rigid material layer. Similarly, the bottom plate
preferably lias a lop surlace with at least four sections that correspond with and are
parallel lo the at least four sections of the; rigid material layer. The mount therefore
includes internal sections prelerably laterally-angled in opposite directions from one
section to the next to form a W-shape, or an inverted YV-shape, in cross-section.
These angled internal surfaces ol the top and bottom plate cooperate with the angled
sections ol the first and second elastic material layers and the rigid material layer lo
result in a lateral horizontal spring rale greater than a longitudinal horizontal spring
rale.
______-—-* " £ K>"—"
In addition, the first and second elastic material layers/may include yut-out
portions defining horizontal longitudinally-extending chambers and, separately or
in combination, vertically-extending chambers. These chambers formed in the cut-
out portions improve the ability lo fine tune the spring rates of the mount. Further,
these chambers improve the fatigue life of the elastic material in the mount by
increasing the bulge area.^ For purposes of this disclosure, the "bulge area" is
defined as the vertical area in which the first elastic layer and the second elastic layer
are free to horizontally expand. The chambers provide the mount with a bulge area
greater than the combined perimeter vertical area of the first and second layers,
defined as the vertical thickness of each layer multiplied by the perimeter length of
each layer
BRTHP DESCRIPTION OF TMl-jjDRAWINGS ^
Fig. I is a fragmentary side elevalional view of one quadrant of a railway
truck, where the other quadrants are symmetrical, incorporating a lateral control
mount;
Fig. 2 is a rear perspective view of one embodiment of the lateral control
mount;
Fig. 3 is a lop plan view of the mount of Fig. 2, with the clashed lines
indicating hidden longitudinal chambers;
Fig. 4 is a side elevational view of the mount of l;ig. 2;
Fig. 5 is a cross-sectional view of the mount taken along line 5-5 of Fig. 3;
Fig. 6 is a lop plan view of a second embodiment of a mount, similar to Fig. 3,
with dashed lines indicating hidden laterally-extending vertical chambers;
F'ig. 7 is a cross-sectional view of the second embodiment of the mount taken
along line 7-7 of F'ig. 6;
Fig. 8 is a cross-sectional view, similar to Fig. 7, of another embodiment of a
mount; and
F'ig. 9 is a cross-sectional view, similar to F'ig. 7, of yet another embodiment of
a mount.
DETAILED DESCRIPTION OF Till' INVENTION
According to one preferred embodiment, referring to F'ig. 1, a mount 10
utilized in a suspension system ol one quadrant of a railway truck 12
advantageously is configured to provide an increased lateral spring rate without
increasing a longitudinal spring rate, thereby improving the steering and ride
characteristics of the railway truck. The railway truck 12 includes wheels 14
mounted at the ends of laterally-extending front and rear axles 16. Only one
quadrant of the railway truck 12 is illustrated in Fig. 1, showing one wheel and one
axle, as the other quadrants are symmetrical. Each axle 16 is rotatably mounted at
each end within an anti-friction bearing IS, such as a roller bearing. Side frame
members 20 longitudinally extend to connect the front and rear axles 16 at the
respective ends of each axle. The side frame members 20 have downwardly
depending pedestal jaws 22 and 24 spaced fore and aft of the bearing 18. The
pedestal jaws 22 and 24 define a load-carrying surface 26 therebetween which is
positioned directly above the bearing 18. A bearing adapter 28 is received in
overlying relation lo and carried by the bearing 18. A load-receiving surface 30 o!
the adapter 28 is spaced directly benealh and presented toward the load-carrying
surface 26 of the side frame 20.
The mount 10 is positioned and interlocked between the load-carrying surface
26 of the side frame 20 and the load-receiving surface 30 of the adapter 28. Referring
to bigs. 2-5, the mount 10 includes a body of elastic material preferably including
first and second elastic material layers 32 and 34 that accommodate horizontal
movemen! of the axles 16 relative to the; side frames 20, while supporting vertical
static and dynamic loads. Additionally, the mount 10 includes a rigid material layer,
plate or shim 36, positioned between and abutting the first and second material
layers 32 and 34, for increasing the compression load-carrying ability of the mount.
Further, the rigid material layer 36 includes at least four sections 36', 36", 36'", 36"",
each laterally angled between a horizontal axis Y-Y and the vertical axis Z-Z (Fig. 2).
Preferably, the sections 36', 36", 36'", 36"" are portions of the rigid material layer 36
that lie in a longitudinally flat plane, where each planar section is angled between
the horizontal plane X-Y and the vertical plane X-Z such that a longitudinal line
through any of the sections is parallel to the X-X axis (Fig. 2). The lateral angular
orientation of the sections 36', 36", 36'", 36"" preferably reverses from one section to
the next, thereby forming an inverted YV-shaped cross-section in the Y-Z plane
(similar to an M-shape with sloping sides, as in Fig. 2), which is parallel to the axle
16 and perpendicular to the side frame 20. In operation, the inverted VV-shaped
cross-section is arranged with the adapter bearing 28 being positioned below the
downwardly-directed outer ends of the inverted form. A non-inveried orientation
of the W-shaped cross-section may also be used in operation. As compared to prior
art rigid material layers having V- or inverted V-shaped cross-sections, the
orientation and geometry of the sections 36', 36", 36'", 36"" of 'he rigid layer 36
unexpectedly provide a horizontal lateral spring rale of a substantially greater
magnitude in a given space. Therefore, the mount 10 maintains a horizontal
longitudinal (fore and aft) spring rale (Kx) and a vertical spring rale ¦'<36'"'); wherein the arrangement of the first elastic
material layer, the second elastic material layer, the rigid material
layer the top plate (38), and the bottom plate (40) being such that
they abut against each other. .
21. The mount (10,70,80,90) as claimed in claim 20, wherein the at least
tour sections of the rigid material layer (36\36",36"\36""} are
arranged to form a W-shape.
22. The mount (10,70,80,90) as claimed in claim 20, wherein each of the
first and second elastic material layers (32,34) has a thickness and
angular orientation selected to result in the lateral horizontal spring
rate having a compression component and a shear component, and
wherein the compression component is greater than the shear
component.
23. The mount (10,70,80,90) as claimed in claim 20, wherein the rigid
material layer (36) has a thickness and angular orientation selected to
result in the lateral horizontal spring rate having a compression
component and a shear component, and wherein the compression
component is greater than the shear component.
24. The mount (10,70,80,90) as claimed in claim 20, wherein each of the
first elastic material layer (32), the second elastic material layer (34)
and the rigid material (36) have a thickness and angular orientation
selected in combination to result in the lateral horizontal spring rate
having a compression component and a shear component and
wherein the compression component is greater than the shear
component.
25. The mount (10,70,80,90) as claimed in claim 20, where within each
respective layer of the rigid material layer (36) and the first and
second elastic material layers (32,34), adjacent sections are integrally
connected to define a transition area (66), and where each transition
area forms a vertically-oriented peak or vertically-oriented valley in
each respective layer.
26. The mount (10,70,80,90) as claimed in claim 25, wherein each
transition area (66) of the rigid material layer forms an arcuate
portion.
27. The mount (10,70,80,90) as claimed in claim 20, wherein the
orientation of the angle of each of the at least four sections of the
rigid material layer (36',36",36"',36"") reverses form one section to
the next section.
28. The mount (10,70,80,90) as claimed in claim 20, wherein said first
elastic material layer longitudinal chamber (62) are cut-out portion
horizontal longitudinally-extending chambers and said second elastic
material layer longitudinal chambers (62) are cut-out portion
horizontal longitudinally extending chambers in alignment with said
first elastic material layer longitudinal chambers (62).
29. The mount (10,70,80,90) as claimed in claim 27, wherein at least one
of the first and second elastic material layers (32,34) includes a cut-
out portion to define a substantially vertically-extending chamber
(72).
30. The mount (10,70,80,90) as claimed in claim 28, wherein each of the
first and second elastic material layers and the rigid material layer
have aligned, vertically oriented cut-out portions that define a
substantially vertically-extending chamber (72).
31. The mount (10,70,80,90) as claimed in claim 28, wherein the
plurality of substantially horizontal, longitudinally-extending
chambers (62) are laterally positioned, from the lowest point or
valley of each laterally angled section of the first and second elastic
material layer, about 1/3 of a total distance from the lowest point or
valley to a highest point or the peak of each laterally angled section
of the first and second elastic material layer (32,34).
32. The mount (10,70,80,90) as claimed in claim 33, wherein each of the
plurality of substantially horizontal, longitudinally-extending
chambers (62) within the first and second elastic material layers
(32,34), respectively, have a diameter about equal to a thickness of
the respective first and second elastic material layer within which the
respective chamber is positioned.
33. The mount (10,70,80,90) as claimed in claim 24, wherein the rigid
material layer (36) includes at least six sections (81,82,83,84,85,86),
and wherein at least six sections (81,82,83,84,85,86) form a WV-
shape.
34. The mount (10,70,80,90) as claimed in claim 24, wherein the rigid
material layer (36) includes at least six sections (81,82,83,84,85,86),
and wherein two of the at least six sections are laterally angled
parallel to the horizontal axis.
35. The mount (10,70,80,90) as claimed in claim 1 wherein the first
elastic material layer comprises sections respectively oriented
parallel with each one of the at least four sections of the rigid
material layer, and the arrangement of the second materials layer
comprises sections respectively oriented parallel with each one of the
at least four sections of the rigid material layers;
each of the sections of the first and second elastic material layers
having at least one horizontal, longitudinally-extending chamber
(62),
the arrangement of the first elastic material layer, the second elastic
material layer and the rigid material layer being such that they abut
against each other in cooperation and have a thickness and angular
orientation selected in combination to result in the lateral horizontal
spring rate greater than the longitudinal horizontal spring rate and
having a compression component and a shear component, and
wherein the compression component is greater than the shear
component.
36. The mount (10,70,80,90) as claimed in claim 35, wherein each of the
horizontal, longitu din ally -extending chambers (62) is laterally
positioned, from the lowest point or valley of each laterally angled
section of the first and second elastic material layer (32,34), about
1/3 of a total distance from the lowest point or valley to a highest
point or the peak of each laterally angled section of the first and
second elastic material layer.
37. The mount (10,70,80,90) as claimed in claim 35, wherein each of the
horizontal, longitudinally-extending chambers (62) within the first
and second elastic material layers (32,34), respectively, have a
diameter about equal to a thickness of the respective first or second
elastic material layer within which the respective chamber is
positioned.

In a mount (10,70,80,90) in a railway truck (12) having a lateral axle (16)
and a longitudinal fore-aft side frame (20), comprising:
a first elastic material layer (32) having a bottom surface and a plurality of
longitudinal chambers (62);
a second elastic material layer (34) having a top surface and a plurality of
longitudinal chambers (62);
a rigid material layer (36) positioned between the bottom surface of the
first elastic layer (32) and the top surface of the second elastic layer (34), a
bulge area of the mount, defined as the sum of a vertical area in which both
of the first elastic material layer and the second elastic material layer are
free to horizontally expand and which includes said longitudinal chambers
(62), each having a perimeter vertical area, characterized in that the
perimeter vertical area for each elastic material layer is defined as a
vertical thickness of the elastic material layer multiplied by a horizontal
perimeter length of the elastic material layer; the mount comprises at least
four sections (36', 36", 36"', 36""), along the rigid material layer, each one
of the at least four sections being laterally angled between a horizontal axis
and a vertical axis, and wherein at least two of the at least four sections are
oriented at angles different from the other two of the at least four sections;
the arrangement of the first elastic material layer (32), the second elastic
material layer (34) and the rigid material layer (36) being such that they
abut against each other in cooperation to result in a lateral horizontal spring
rate greater than a longitudinal horizontal spring rate; and wherein the
bulge area is greater than the sum of a perimeter vertical area of the first
and second elastic material layers.