U.S. patent number 3,782,294 [Application Number 05/169,231] was granted by the patent office on 1974-01-01 for articulated railway truck swinging bolster.
This patent grant is currently assigned to Rockwell International Corporation. Invention is credited to Gustav B. Sundby.
United States Patent |
3,782,294 |
Sundby |
January 1, 1974 |
ARTICULATED RAILWAY TRUCK SWINGING BOLSTER
Abstract
Railway trucks which include front and rear wheel and axle
assemblies, frame sections supported from said wheel and axle
assemblies, spherical bearing assemblies connecting said frame
sections for pivotal movement about a diagonal axis, spring seats
supported from the side frames by articulated swing hangers,
laterally deflectable spring assemblies on the spring seats, and a
bolster supported by said spring assemblies.
Inventors: |
Sundby; Gustav B. (Atchison,
KS) |
Assignee: |
Rockwell International
Corporation (Pittsburgh, PA)
|
Family
ID: |
22614739 |
Appl.
No.: |
05/169,231 |
Filed: |
August 5, 1971 |
Current U.S.
Class: |
105/190.1;
105/193; 105/198.1 |
Current CPC
Class: |
B61F
5/10 (20130101); B61F 3/04 (20130101) |
Current International
Class: |
B61F
5/02 (20060101); B61F 3/04 (20060101); B61F
5/10 (20060101); B61F 3/00 (20060101); B61f
003/08 (); B61f 005/10 (); B61f 005/12 () |
Field of
Search: |
;105/182R,187,19R,193,197B,19R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Forlenza; Gerald M.
Assistant Examiner: Beltran; Howard
Attorney, Agent or Firm: William A. Strauch et al.
Claims
What is claimed and desired to be secured by Letters Patent is:
1. A railway truck comprising front and rear wheel and axle
assemblies; side frames supported from said wheel and axle
assemblies; spring support means at each side of said truck;
articulated swing hangers; a bolster extending laterally across
said truck; vertically extending, laterally deflectable spring
means disposed on said spring support means and supporting said
bolster therefrom; and first and second means pivotally connecting
said swing hangers to said side frames and to said spring support
means respectively for movement about axes extending in the same
direction as the side frames, the second of said means connecting
said swing hangers to said spring support means at generally the
level at which the spring means inflect as said bolster moves
laterally relative to said side frames and laterally displaces the
upper ends of said springs relative to the lower ends thereof.
2. A railway truck comprising front and rear wheel and axle
assemblies; a frame including laterally spaced apart side frames,
said frame being supported from said wheel and axle assemblies; a
spring support at each side of said truck; fore and aft swing
hangers supporting each of said spring supports from the side frame
on the same side of the truck, each said swing hanger comprising an
upper link supported from the side frame for pivotal movement about
an axis extending longitudinally of the truck, a lower link fixed
to said upper link for pivotal movement about a second axis
extending longitudinally of the truck, and means fixing the lower
link to the spring support for pivotal movement about a third axis
extending longitudinally of the truck; laterally deflectable spring
means seated on each of said supports, each said spring means
having a plane of deflection at the level at which the spring
supports are pivotally fixed to the lower links of the swing
hangers; and a bolster extending laterally across said truck, said
bolster being supported by the spring means at the opposite sides
of the truck.
3. The railway truck of claim 2, together with stop means for
limiting lateral movement of said bolster relative to said truck
frame.
4. The railway truck of claim 2, wherein each swing hanger includes
a second lower link pivotally fixed to said upper link and to said
spring support in laterally spaced relation to the first-mentioned
lower link.
5. The railway truck of claim 2, wherein each of said laterally
deflectable spring means comprises an inner coil spring, and outer
coil spring surrounding the inner coil spring, and an air bellows
surrounding the outer coil spring.
6. A railway truck comprising front and rear wheel and axle
assemblies; a truck frame including laterally spaced apart side
frames supported from said wheel and axle assemblies; spring
support means at each side of said truck; swing hangers supporting
said spring support means from said side frames; a bolster; and
vertically extending, laterally deflectable spring means disposed
on said spring support means for supporting said bolster therefrom,
for cushioning lateral movements of the bolster relative to the
side frames, and for providing a laterally acting force for
restoring the bolster to a centered position relative to said side
frames, the upper ends of said spring means being fixed for
movement with said bolster and the lower ends thereof being fixed
for movement with said spring support means.
7. The railway truck of claim 6, together with lateral and vertical
shock absorbers and radius rods connected between said bolster and
said truck frame for cushioning relative movement between said
bolster and said truck frame.
8. A railway truck including a frame comprising a first frame
section having a first side frame and a first transom rigid with
said first side frame and extending laterally therefrom, a second
frame section having a second side frame and a second transom rigid
with said second side frame and extending laterally therefrom, said
second transom being spaced from said first transom longitudinally
of the truck; wheel and axle assemblies journalled in said frame
sections at opposite ends of the truck and providing wheels at
locations corresponding generally to the four corners of said
truck; first and second means for so connecting said first frame
section to said second frame section as to permit vertical
displacement of any one of said wheels relative to the remaining
wheels while maintaining said side frames substantially in
rectangular and vertical tram, said first and second connecting
means confining the relative movement between said first and second
frame sections to an axis extending diagonally across said truck
through said first and second connecting means; spring seats at
each side of said truck; swing hangers supporting said spring seats
from said side frames, each said swing hanger comprising an upper
link pivotally supported from the associated side frame and a lower
link pivotally connected to the first link and pivotally connected
to the associated spring seat; a bolster extending laterally across
said truck; and coil spring means on the spring seat at each side
of said truck supporting said bolster, the inflection of said coil
spring means as said bolster moves laterally relative to said side
frame being at generally the same level as the pivot connections
between the lower links of the swing hangers and the spring
supports.
Description
This invention relates to novel, improved railway trucks.
At the present time large sums of money are being spent for rolling
stock intended for high speed passenger service. One of the
requirements of such stock is that it provide a comfortable ride
under a variety of service conditions.
To produce a comfortable ride, it is necessary to absorb shocks
generated by lateral offsets in tracks such as occur at frogs,
switches, and crossovers, for example. Also it is necessary to
cushion and limit lateral movement of cars as they negotiate curves
at high speeds or are otherwise subjected to high lateral forces or
loads. Aside from producing a comfortable ride, it is also
necessary to limit lateral movement of the bolsters and therefore
the car body relative to the track in such stock because of the
limited clearances at station platforms, for example.
One important object of the invention resides in the provision of
novel railway trucks capable of providing a ride of superior
quality under a wide variety of track, load, and other service
conditions.
Another important object of the invention resides in the provision
of railway trucks with novel, improved bolster suspension systems
for cushioning laterally acting loads of both low and high
magnitudes and for limiting lateral movement of a carbody relative
to a railroad track.
The novel railway trucks of the present invention, by which the
foregoing and other objects are achieved, include a pair of frame
sections supported from front and rear wheel and axle assemblies.
Each of the frame sections includes a longitudinal side frame and a
transom extending transversely from it, the two transoms being
spaced longitudinally of the truck. The two frame sections are
connected by spherical bearings in the manner described in U.S.
Pat. No. 3,313,245 issued Apr. 11, 1967, to maintain the side
frames in rectangular and vertical tram.
A carbody supporting bolster is supported from the truck side
frames by novel bolster support assemblies which include laterally
deflectable coil spring assemblies interposed between the bolster
and spring seats located below the bolster at opposite ends
thereof. The spring seats are supported from the side frames by
articulated swing hangers.
When there is a small displacement of the carbody relative to the
truck frame as caused by an offset in a track, for example, this
novel combination of laterally deflectable coil springs and
articulated swing hangers provides relatively low magnitude
restraining and restoring forces which absorb the shock and prevent
it from being transmitted to the carbody. In the case of larger
lateral forces such as occur in high speed curve negotiation, for
example, these suspension components combine to produce much larger
restraining and restoring forces and thereby prevent unwanted
motions of the carbody.
Bolster suspension systems employing articulated swing hangers have
heretofore been proposed (see U.S. Pat. No. 1,867,654 issued July
19, 1932, to H. T. Casey for SWING HANGER FOR RAILWAY TRUCKS). The
Casey suspension system, however, differed considerably from that
employed in the novel trucks disclosed herein. In the latter, the
articulated swing hangers alter the action of laterally
deflectable, bolster supporting coil springs so that the springs
have a low restraining force for absorbing shocks and the like, but
a greater restraining effect when the laterally acting force is of
larger magnitude. The Casey arrangement does not employ laterally
deflectable bolster springs, but depends on the exertion of a
lifting effect on the truck bolster to produce a restoring force.
This comparatively primitive arrangement would not be satisfactory
for modern day high speed service.
The use of coil springs to provide lateral restoring and
restraining forces has also heretofore been proposed. Typical of
the patents disclosing such systems are U.S. Pat. Nos. 2,723,628
issued Nov. 15, 1955, to W. T. Rossell for BOLSTER ASSEMBLY and
2,737,126 issued Mar. 6, 1956, to the same inventor for
DIFFERENTIALLY ACTING BOLSTER CONTROL. In these and other
heretofore proposed bolster suspension systems employing laterally
deflectable springs, however, the bolster is supported directly
from the truck side frames by the springs rather than through the
intermediary of articulated swing hangers.
In short, there has heretofore been no recognition of the
advantages that may be realized by employing laterally deflectable
springs in combination with articulated swing hangers in bolster
suspension systems.
Primary objects of the present invention have been described above.
Other important objects and advantages and further novel features
of the present invention will become apparent from the appended
claims and as the ensuing detailed description and discussion
proceeds in conjunction with the accompanying drawing, in
which:
FIG. 1 is a side view of a railway truck constructed in accord with
the principles of the present invention;
FIG. 2 is a plan view of the truck of FIG. 1;
FIG. 3 is a section through the truck of FIG. 1, taken
substantially along line 3--3 of FIG. 2; and
FIG. 4 is a section through the truck of FIG. 1, taken
substantially along line 4--4 of FIG. 2.
Referring now to the drawing, FIGS. 1 and 2 depict a railway truck
20 constructed in accord with the principles of the present
invention. Truck 20 may be of the same basic construction as the
novel truck described in the above-cited U.S. Pat. No. 3,313,245.
The truck has a rectangular frame 26 consisting of two generally
L-shaped, rigid subassemblies or frame sections 28 and 30. These
subassemblies are formed by longitudinally extending side frames 32
and 34 secured to or integral with laterally extending,
longitudinally spaced transoms 36 and 38.
Frame sections 28 and 30 are interconnected at diagonally opposed
points by spherical bearing assemblies 40 and 42 to permit relative
pivoting between them about a diagonal axis 44 through the centers
of the spherical bearings and the center of the truck.
Truck frame 26 is supported on axles 45 and 46 by roller bearing
assemblies 48 which are resiliently mounted in frame 26. Axles 45
and 46 each have railway wheels 50 secured thereto.
Because of the manner in which the frame subassemblies 28 and 30
are interconnected by bearing assemblies 40 and 42, there is only
one type of motion therebetween. This is a pure pivotal movement of
one sub-assembly with respect to the other about axis 44.
Accordingly, as truck 20 rolls onto an uneven stretch of track on
which one of the wheels 50 furthest from axis 44 is at a low point
in the track, the associated frame subassembly tends to pivot
downwardly about axis 44 to re-establish even wheel loading.
Conversely, when a wheel furthest from the pivoting axis is on a
high point on a rail, its frame sub-assembly pivots upwardly about
axis 44 to re-establish even wheel loading.
Thus, the construction of frame 26 provides independent side frame
action. However, as the spherical bearings do not permit
longitudinal play between the frame sub-assemblies, the side frames
of the truck 20 are rigidly maintained in rectangular tram.
Further, as the spherical bearings do not permit vertical play
between the ends of the transoms and the opposite side frames, the
side frames are maintained in vertical tram. Finally, as the
spherical bearings permit no lateral play between the transoms and
the opposite side frames, they effectively rigidly transmit lateral
forces from one side to the other..sup.1
Supported from truck frame 26 are motors 52 driveconnected to axles
45 and 46 by gear boxes 54 as well as brake assemblies 56. These
components are not part of the present invention and will
accordingly not be described further herein.
Also supported from truck frame 26 by novel suspension assemblies
58 is a transversely extending bolster 60. Bolster 60, which is of
generally conventional construction, has an integral fitting 62
which co-operates with a depending member (not shown) and a safety
hook 63 fixed to the underside of a carbody 64 to pivotally support
one end of the carbody from truck 20. Liners 65 and 66 in the
recess 67 in fitting 62 minimize resistance to relative pivotal
movement between the truck and the carbody.
Referring now to FIGS. 1-4, each of the bolster supporting
assemblies 58 includes a spring support or seat 68 supported from a
truck side frame 32 or 34 by a pair of articulated swing hangers 70
and 72 together with a spring assembly 74 disposed on the seat and
abutting a spring cap 76 at the end of bolster 60.
As best shown in FIG. 4, each of the spring assemblies 74 includes
an inner coil spring 78, an outer coil spring 80, and an air
bellows 82 surrounded by a reinforcing ring 83. The two coil
springs 78 and 80 are positioned by annular flanges
Bellows 83 are fixed to the associated spring seats and spring caps
by annular retainers 88 and 90, which are bolted to these
components. As shown in FIG. 4, these retainers are configured to
interlock with flanges 92 and 94 at the lower and upper ends of the
bellows to form gas tight seals between spring support 68 and the
lower end of the bellows and between the upper end of the bellows
and spring cap 76. In operation, the interiors of the bellows 82
are pressurized so that carbody 64 is supported by a combination of
air and spring suspension.
To limit the lateral movement of spring supports 68 and bolster
spring assemblies 74 relative to bolster 60, lateral control pins
96 are employed. These pins are fitted into apertured bosses 98 on
the lower side of the bolster and extend downwardly through an
aperture 100 in a vertical arm 102 at the inner end of said spring
support. Washerlike members 104 and 106 are welded to support arms
102 to reinforce the areas around the apertures.
Referring now specifically to FIGS. 1 and 3, each of the
articulated swing hangers 70 and 72 includes an upper arm of
pendulum 108 and two pairs of lower arms or shackles 110 and 112.
As best shown in FIG. 1, pendulums 108 are supported from side
frames 32 and 34 for lateral pivotal movement about an axis
parallel to the longitudinal axis of truck 20 by pivot members 114.
These pivot members extend through the upper ends of the pendulums
and through brackets 116 and 118 fixed to the associated side frame
on opposite sides of each pendulum.
Turning now to FIG. 3, frame sections 28 and 30 are of hollow, cast
construction; and each pendulum 108 extends downwardly through an
aperture 120 in the upper or top wall 122 of the associated frame
section and an aperture 124 through an integral, vertically
oriented, flangelike portion 126 on the lower side of the frame
section.
Stops 128 are fixed in each aperture 124 on opposite sides of the
associated pendulum 108 by cap screws 130 and are separated from
the cap screws as by shims 132. Stops 128 limit the lateral,
swinging movement of pendulums 108 relative to the side frames with
which they are associated.
As will be apparent from FIGS. 1 and 3, there is one pair of
shackles 110 at the outer side of each pendulum and one pair 112 at
the inner side. At their upper ends, shackles 110 are fixed to the
pendulum on opposite sides thereof as by a pivot member 134. The
upper end of shackles 112 are similarly fixed to the pendulum at
the inner side thereof as by a pivot member 136.
The shackles 110 of swing hangers 70 and 72 are pivotally fixed to
integral upstanding flanges 138 and 140 at the front and rear of
the associated spring support 68 by pivot members 142 and 144. The
shackles 112 of the two hangers are similarly fixed to these
flanges inwardly of shackles 110.
As mentioned briefly above, it is the function of the novel
suspension assemblies 58 just described to isolate carbody 64 from
shocks due to lateral offsets in a track and the like by providing
relatively low restraining and restoring forces and to produce such
forces of higher magnitudes during high speed curve negotiation,
for example, to prevent unwanted motions of the carbody. A relative
lateral force between bolster 60 (and accordingly carbody 64) and
truck frame 26 will cause swing hangers 70 and 72 to pivot about
pins 114. This displaces the lower ends of the coil springs 78 and
80 in bolster suspension assemblies 74 relative to the upper ends,
the springs absorbing the lateral force as this displacement
occurs. When the force is dissipated, the springs restore to their
original configurations. This returns the bolster and carbody to
their normal positions with respect to the truck frame.
If the lateral force has a relatively low magnitude, the swing
hangers 70 and 72 pivot about members 114 as solid links; i.e., the
shackles 110 and 112 do not pivot relative to the pendulum 108.
Accordingly, the displacements of springs 78 and 80 are relatively
small; and the resistance of relative lateral movement between the
bolster and truck frame as well as the forces exerted by these
springs in restoring the bolster and carbody to their centered
position are low. This type of operation is particularly effective
for absorbing shocks and the like, yet permits the relatively free
lateral movement between the carbody and truck frame on straight
track which is needed for a high quality ride.
If the displacement effecting forces are larger, the action of the
suspension assemblies will initially be the same. However, as the
swing hangers continue to pivot, pendulums 108 engage stops 128,
which prevent further lateral movement of the pendulums.
Thereafter, shackles 110 and 112 pivot laterally about pivot
members 134 and 136. Because of the shorter moment arm, the
displacement of the lower spring ends relative to the upper spring
ends increases as does the restraining effect and the restoring
force exerted by the springs. Accordingly, the springs are in such
circumstances capable of smoothly absorbing these larger laterally
acting forces.
As the upper and lower ends of springs 78 and 80 are displaced
relative to each other, the spring configuration is such that,
taking a lateral plane through each spring and considering one edge
of the two dimensional figure thus produced, this edge is a
compound curve. One portion of the curve is concave and the other
convex.
The level at which the transition between the concave and convex
curves occurs is conventionally known as the point or level or
plane of inflection. For suspension systems 58 to operate
satisfactorily, the level at which shackles 110 and 112 are
pivotally connected to spring supports 68 (i.e., the level of pivot
members 142 and 144) must be approximately the same as the level or
plane of inflection of the springs in bolster supporting spring
assemblies 74.
Provision is preferably made in the novel railway trucks of the
present invention for positively limiting lateral movement of the
supported carbody relative to the truck frames and for cushioning
abnormally large shocks; i.e., shocks having a magnitude greater
than those which assemblies 58 are designed to accommodate. In the
exemplary embodiment of the invention illustrated in the drawing,
these objectives are accomplished by resilient stops 146 fixed to
integral, upstanding brackets 148 at the ends of bolster 60. Under
the influence of abnormally large lateral forces, one of the stops
146 will engage the inner wall 150 of a side frame 32 or 34 to
cushion the shock and to limit the movement of bolster 60 and
carbody 64 laterally with respect to truck frame 26.
To further increase ride quality, the novel trucks of the present
invention are also preferably equiped with radius rods 152, lateral
shock absorbers 154, and vertical shock absorbers 156. These
components, which are connected between truck frame 26 and bolster
60, are of conventional construction and function in the usual
manner. For this reason and because they are not part of the
present invention, it is not believed necessary to described them
in detail herein.
While the principles of the present invention have been described
with reference to motorized trucks, it will be obvious to those
familiar with the arts to which this invention relates that they
are equally applicable to unmotorized trucks. It will also be
apparent to such persons that the principles of the invention can
be embodied in trucks differing widely in appearance from the truck
illustrated in the drawing. Such applications of the principles
described herein are fully intended to be covered in the appended
claims to the extent that they are not expressly excluded
therefrom.
The invention may be embodied in other specific forms without
departing from the spirit or essential characteristics thereof. The
present embodiment is therefore to be considered in all respects as
illustrative and not restrictive, the scope of the invention being
indicated by the appended claims rather than by the foregoing
description, and all changes which come within the meaning and
range of equivalency of the claims are therefore intended to be
embraced therein.
* * * * *