CENTER CLAMP ASSEMBLY FOR FRAME BRACE RAIL TRUCK

BRIDE CENTRALE DE SERRAGE POUR ENTRETOISE DE CADRE DE BOGIE

English Abstract

A rail car truck has a pair of longitudinally spaced wheelsets and a pair of laterally spaced side frames which extend between and are supported by the wheelsets. A bolster extends between the side frames to support the rail car vehicle body. There is a brace which is connected to the side frames to control relative longitudinal movement therebetween. The brace includes a pair of struts which are diagonally connected to the side frames on opposite sides of the centerline thereof. The struts intersect generally centrally of the side frames and there is a clamp assembly for attaching the struts together. The clamp assembly includes a pair of clamp plates, each having a channel formed and adapted to receive a strut. Each clamp plate channel terminates at opposite ends of the clamp plate, with each clamp plate channel having a generally U-shaped opening. Each clamp plate is welded to a strut along the generally U-shaped openings thereof. There are fasteners which attach the facing surface of the clamp plates directly to each other. The clamp plates are welded, one to another. The clamp plate assembly inhibits relative movement between the struts in a generally horizontal plane.

French Abstract

Un bogie comprend une paire d'essieux montés espacés longitudinalement et une paire de cadres latéraux espacés latéralement qui s'étendent entre les essieux montés qui les supportent. Une traverse s'étend entre les cadres latéraux pour supporter le corps du bogie. Une entretoise est reliée aux cadres latéraux pour contrôler le mouvement longitudinal relatif entre les deux. L'entretoise comprend une paire d'amortisseurs qui sont raccordés diagonalement aux cadres latéraux sur les côtés opposés de leur centre. Les amortisseurs se croisent généralement au centre des cadres latéraux et un dispositif de pince sert à fixer les amortisseurs ensemble. Le dispositif de pince comprend une paire de plaques de pince, chacun comportant un canal formé et adapté pour recevoir un amortisseur. Chaque canal de plaque de pince se termine aux extrémités opposées de la plaque de pince, et chaque canal de plaque de pince comporte une ouverture généralement formée en U. Chaque plaque de pince est soudée à un amortisseur le long de ses ouvertures généralement en forme de U. Des attaches servent à fixer la surface avant des plaques de pince directement l'une à l'autre. Les plaques de pince sont soudées l'une à l'autre. Le mécanisme de plaque de pince empêche le mouvement relatif entre les amortisseurs dans un plan généralement horizontal.

Claims

The embodiments of the invention in which an exclusive property or privilege
is claimed are defined as follows:
1. A truck comprising a pair of longitudinally spaced wheelsets, a pair of
laterally spaced side frames extending between and supported by said
wheelsets, a bolster
extending between said side frames to support a vehicle body, and a brace
connected between
said side frames to control relative longitudinal movement therebetween, said
brace including
a pair of struts oppositely inclined to the longitudinal axis of the truck and
each extending
between the side frames, said struts intersecting generally centrally of said
side frames, and a
clamp assembly for attaching said struts at their intersection, said clamp
assembly including a
pair of clamp plates, each plate having a generally parallelogram
configuration, and having a
generally central channel formed and adapted to receive a strut, each clamp
plate channel
terminating at opposite ends of the clamp plate, with each clamp plate channel
end having a
generally U-shaped opening, each clamp plate being welded to a strut along the
U-shaped
openings thereof, and fastening means attaching facing surfaces of said clamp
plates in direct
contact with each other.
2. The truck of claim 1 wherein each clamp plate is welded to a strut at
spaced locations along each clamp plate channel.
6

3. The truck of claim 1 wherein each strut, in the area of the clamp assembly,
has a somewhat flat surface on one side thereof and an irregular surface on
the opposite side
thereof, with the generally flat surface being welded at the U-shaped opening
to a clamp
plate.
4. The truck of claim 1 wherein said clamp plates are welded, one to another,
along adjacent sides thereof to inhibit relative movement between said struts
in a generally
horizontal plane.
5. The truck of claim 1 wherein there are two fastening means, one located
on each side of the crossing channels.
6. The truck of claim 1 wherein each plate has a long axis and a short axis,
with the plate channel extending along the long axis.
7

Description

CA 02305610 2000-04-12
CENTER CLAMP ASSEMBLY FOR FRAME BRACE RAIL TRUCK
THE FIELD OF THE INVENTION
The present invention relates to frame braced rail car trucks of the type
described in U.S. Pat. Nos. 4,570,544, 5,243,920 and 5,584,250, all assigned
to the
assignee of the present application, Standard Research and Design Corporation
of Park
Ridge, Ill. In the '544 patent the diagonal braces or struts which
interconnect the side
frames are held together at their intersection by a shackle 66. In the '920
patent the struts
are interconnected where they cross by a clamp plate assembly consisting of
two clamp
plates, each with a channel, and an elastomeric pad between the facing
surfaces of the clamp
plates and the struts. There are fasteners which hold the clamp plates
together.
In the '250 patent the clamp plates are welded to the frame brace struts and
the
clamp plates are welded to one another. Although this welded assembly provided
a
substantially strengthened interconnection, the welds were located at an area
of high residual
stress. The present invention modifies the configuration of the welds between
each strut and
a clamp plate by the provision of U-shaped cutouts at each end of a clamp
plate channel,
with the struts being welded to the clamp plates along the edges of the U-
shaped openings.
SUMMARY OF THE INVENTION
The present invention relates to frame brace trucks in which a pair of cross
struts are used to stabilize the truck and improve the resistance to relative
longitudinal
movement between the side frames.
A primary purpose of the invention is to provide an improved and substantially
strengthened clamp assembly for attaching the cross struts between the side
frames.

CA 02305610 2000-04-12
Another purpose is to provide a clamp assembly of the type described using a
specific geometric shape for the weld between each clamp plate and a strut,
which weld
shape increases fatigue resistance.
Another purpose of the invention is to utilize U-shaped welds between the
clamp plates and the struts, which welds are closer to the neutral axis of the
lateral bending
load, thus reducing stress in the welds.
Other purposes will appear in the ensuing specification, drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated diagrammatically in the following drawings
wherein:
Fig. 1 is a side view of a rail car truck of the type disclosed herein;
Fig. 2 is a bottom view of the rail car truck of Fig. l;
Fig. 3 is a top view of the upper frame strut;
Fig. 4 is a side view of the upper frame strut;
Fig. 5 is a top view of the lower frame strut;
Fig. 6 is a side view of the lower frame strut;
Fig. 7 is an enlarged view of the top of the upper clamp or a bottom view of
the lower clamp;
Fig. 8 is an enlarged view of the bottom of the upper clamp or the top of the
lower clamp;
Fig. 9 is a section along plane 9-9 of Fig. 7;
Fig. 10 is an enlarged bottom view of the clamp assembly; and
2

CA 02305610 2000-04-12
Fig. 11 is a section along plane 11-11 of Fig. 10.
DESCRIPTION OF THE PREFERRED EMBODIMENT
U.S. Patent No. 4,570,544 discloses a railroad truck having a pair of side
frames supported on conventional longitudinally spaced wheelsets. To improve
truck
stability, cross struts extend between the side frames to increase the
resistance to side frame
relative longitudinal movement. Elastomeric members are placed between the
wheelsets and
the side frames to decrease the yaw stiffness of the wheelsets. As a result,
the yaw stiffness
and lateral stiffness of the truck can be selected to provide optimum truck
stability.
U.S. Patent No. 5,243,920 discloses an improvement of the '544 truck,
specifically in the area of the clamp that holds the cross struts together at
a location generally
at the mid-point between the side frames. The '250 patent was an improvement
on the clamp
assembly of the '920 patent in that it strengthened the connection between the
cross struts
and eliminated the elastomeric member of the '920 patent. The present
invention provides
yet a further improvement in the clamp assembly in that by repositioning the
welds between
each clamp plate and a strut, it increases the fatigue resistance of the welds
and reduces the
stress in the welds. This provides a clamp assembly which is both strengthened
and which
has a substantially increased useful life.
In the drawing, conventional side frames are indicated at 10 and are mounted
on wheelsets 12 and 14. Conventional roller bearings mount the wheelsets and
the side
frames are connected by a bolster 16. The bolster is supported on the side
frame by springs
17, as is conventional.
Cross struts 18 and 20 are diagonally connected between the side frames to
3

CA 02305610 2000-04-12
provide the desired resistance to relative longitudinal movement between the
side frames.
Each end of a cross strut 18, 20 is attached to a side frame by means of a
mounting bracket
22 which is attached by a base plate 24 to the side frame. An end block
assembly 26 is
attached to the brackets 22 and has a nose, not shown, which extends within
and supports
each of the cross struts 18 and 20. The end block assembly and the mounting
therefor
includes an elastomeric element to provide yaw and lateral stiffness.
The clamp assembly is indicated generally at 30 and is shown in detail in
Figs.
3-11. the clamp assembly includes an upper clamp plate 32 and a lower clamp
plate 34, the
clamp plates being identical in configuration. Each clamp plate includes a
generally central
trough 36 within which is positioned a central portion 38 of one of the struts
18 and 20.
The central portion 38 of each of the struts, as more particularly shown in
the
cross sections of Figs. 9 and 11, includes what may be termed an upper surface
40 which,
although slightly curved, is relatively flat when compared with the lower
surface 42, which is
irregular in shape and has an in-turned central area 44.
The troughs 36 are formed and adapted to receive the central sections of the
struts, and at each end of a trough 36 there is a generally U-shaped opening
48. Each strut
is welded to a clamp plate at the area of the U-shaped openings 48, as
indicated at 50 in Fig.
7. Further, each strut is welded along its sides at spaced locations to the
trough 36, as
indicated at 52 in Fig. 8. Thus, there are welds along the sides of each strut
and the trough
of the clamp plates and there are welds between the U-shaped openings at each
end of each
clamp plate trough and the struts.
Each of the clamp plates 32 and 34 has the configuration of a parallelogram
4

CA 02305610 2000-04-12
with sides 54, with the sides being such that the clamp plate has a long axis
which is parallel
with the trough, and a short axis which is perpendicular to the trough. The
clamp plates are
fastened together by means of fasteners 56, which extend through aligned holes
57 in the
clamp plates to provide the clamp plate assembly, as indicated in Figs. 10 and
11.
In assembly, the struts will first be welded to a clamp plate by the welds 50
and 52. The clamp plates will then be assembled, as indicated in Fig. 10, and
will be held
together by the fasteners 56. The clamp plate assembly is then completed by
means of welds
58 along adjoining edges of the clamp plates, again as illustrated in Fig. 10.
In use, the clamp assembly provides a rigid, strong interconnection between
the cross struts or cross braces. Each of the struts is welded to a clamp
plate, and after the
clamp plates are assembled, they are welded together along adjacent edges. The
use of U-
shaped openings and welds along those openings is important. By locating the
welds at the
U-shaped openings at the end of each clamp plate trough, the weld has been
moved from an
area of high residual stress to an area of low residual stress. In this
connection, it should be
noted that the U-shaped welds between the clamp plates and the struts are
along the generally
flat or slightly curved surface 40 of the struts, which is an area of low
residual stress for the
strut. Further, the U-shaped welds are located closer to the neutral axis of
the lateral
bending load applied to the clamp assembly. This reduces the stress in the
welds which
again increases the effective life of the clamp assembly.
Whereas the preferred form of the invention has been shown and described
herein, it should be realized that there may be many modifications,
substitutions and
alterations thereto.
5

Representative Drawing