Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~0~33~ 7~
Thi~ invention relates to a railway truck assembly,
and moxe particularly, to the pivotal connection in a railway
truck designed for a rapid transit system~
The conventional railway trucJs~ have been desiyned to
meet substantially leRJ stringent requirement~ than thoE;e which
have ~o be met by the ~ruc~ for the urban rapid tran~it ~ystems
now on the drawing boards and/or under devlelopment for the next
generation. Such urban transit system~ are required to bs sub~t-
antially les~ noisy, to be able to negotiate curves much ~harper
than those of conventional railroads, and to be liyhter and thus
more comPatible with energy conservat$on.
The ability for a railway truck to negotiate relatively
sharp curves with a minimum of wear and noise has been provided
by ~teerin~ the wheel axle~ alway~ radially to the curve. A
truck ~ apted to produce such st~ering i~ defined in United
State3 Patent No~ 3,789,770 and in the corresponding Canadian
Patent No. 1~004,543. The railway truck of these patent~
essentially include~ a pair of yokes pivoted o~e to the other
abQut a vertical aXiB and connected to the wheel axles res~ect-
ively which ~y ~uch pivoting will be steered each to a xadialpo.~itio~ relative to a curve.
. `'`
. .,
:`
. .
. .
8~ ,
~i3~
It is a general object of th~ present invention
to provide a railway truck of the above type which provides a
centerles~ pivot connection between the bolster and the truck
frame element~.
It is another object o~ the present invention to provide
a railway truck a~sembly having a pivot connection which in
cooperation with the transmis~ion of the car 1OAd dlrectl~
throu~h the end~ o~ the bol~ter ~llows to use thin and non-
bulgin~ bol~ter thereby increasing the underlying central space
and reducing the weight of the ovarall truck a~sembly.
$~ i~ a urth~r object of tha pr~sent invention
to provide a railway truck a~embly which take~ advanta~e of
the ~mall angular displacements involved to u~e link connections
~imply having swivelling rod end~ to allow the necessary free-
dom of pivoting and twl~ting motions between the movable comp-
onent~.
Theabove and o~her objects and advantage~ of the
: present invention will be better understood with reference to the
following detailed de~cription of a preferred embodiment there-
of which i~ illu~rated~,by way of exa~Dle, in the accompanying
drawin~; in which: . ~
Figure 1 i8 a ~lde elevation view of a railway car
provided with a p~ir o~ railway trucks according to th~ pre~ent
invention;
'i,~.,~ '
.,.~
Pigure ~ i~ a side elevation view of a railway truck
assembly according to the present invention;
Figure 3 i8 a top plan view of the railway truclc
assembly as ~een along line 3-3 in Figure 2;
Figure~ 4 a~d 5 are longitudinal and transverse cross-
sec-tional views as ~een along lines 4-4 and 5-5 respect.ively in
Figure 3;
Figure 6 i8 an enlarged detail view of a suspension
link and pin assembly as ~een along line 5-5 in Figure 3;
Figur~ 7 is a schematic diagram giving in plan lview the
pivotal relationship betwe~rl the pivoting element3 of a pair of
truck~3 and the railway car body carried by the truck~; and
Figure 8 i8 an enlarged view of the lef t truck of
Figure 7.
The railway truck 1 according to the p:re~ent invention,
~.
as ~hown in Figure 1, i8 used in a pair to carry a car body 2
of any desired construction. The railw~y truck 1 forms part
of a railway truck as~embly also comprising a bolster 3 and the
a~sociated element~ to ~upport th~ car body.
The ~ol~ter 3 includes a central portion 4 of tubular
construction having a uniform ~3quar~ cro~ s~ct.ion, as be3t
~hown in Figures 3 and ~. Each end of the bolstar 3 includes
a baseplate portion 5 which i~ positioned lower than the central
bol~ter portlon 4. Stiffening ribs 6 are s~cured again~t the
bottom o each basePlate portion S and extend longitudinally
of the bolster. Each baseplate portion 5 i8 provided with a
pair of side plate~ 7 ~pwardly extending edgewi~e along the
oppvsite side~ thereof. A generally C ~hape top plate 8 is
fixed on the upper edgë of each pair of adjacent side plate~
7 to cooperatiYely orm with th~ latter and with th~ cor~res~
ondirsg baseplate portion S a protected rece~s f:or an air spring
,: ~
~5~7~
unit 9. The latter may ~e of any appropri.ate and known conatr
uction currently used in the artO The two air springs 9 of
each bolster 3 are fixed to the railway c~ir body 2, Ruch a~ by
bolts 10 and carry the load oE the corresponding end of the car
body~ The two side plates 7 on the inboard side of the bolster
3 are connected ~o the car body 2 by means of a pair of bol~ter
drag link~ or rods 11. More specifically, each bolster drag
link or rod 11 has ona end pivoted to the corresponding ~ide
plate 7 of the bolstex and the other end pivotally conrlected to
a bracket 12 fixedly ~ecured to and downwardly projecting from
the bot~om Qf the railway car body. The opposite ends o each
bol~ter draq lin~ 11 are vertically pivoted to accommodate the
springing movement between the car body and the bolster and they
are ~lso provided with resiliently twisting rod ends to accommo- -
date the very small t~ansverse displac ment of the car body rel-
ative ~ the bolster.
The railway truck assembly further includ~s an outboard
and an inboard yokes 13 and 14 resPectiYely. The outboard yoke
13 includes a main frame 15 whi~e the inboard yoke 14 include~
a main frame 16. Each main frame lS and 16 include~ a pair of
laterally spaced apart projections 17 to which is secured a
journal housinq 18. Each main frame 15 and 16 i5 formed with an
underlying transverse beam Portion 19. The journal housinqs 18
of each yoke 13 and 14 xotatably retain a wheel axle 20 having
a flanged wheel 21 on each of the two oppo~ite outer end~ there-
of. Thus, ~.he flanged wheel~ 21 are adapted to Cal'r~ the yokes
and the re ~ inder of ~he railway truck ~s~embly rollabl~ on rails
22.
The oukboard yoke 13 is provided with a longitudinal
bar 23 rigidly secuYed centrall~ to the main frain~ 15 and vroject-
ing inboard therefrom. Similarly~ the ~ain frame 16 is provided
~ID53~7~j
with a longitudinal bar 24 which i5 rigidly secured centrally
thereto and project~ outboard therefrom. The two bar~ 23 and
24 have their free end pivoted one to the other at equal dist-
ances from the wheel axles 20 and thus, cerltrally under the
bolster 3.
A bracket 25 i5 fixedly securecl against th2 outboard
side oE the bol~ter 3 and at the cent~r thereof. A pair of yoke
suspen~ion link~ 26 are pivoted at the upper end to the bracket
25 and at the lower end to the head of a vertical pivot pin 27.
The latter is arranged to pivotally -~u~pend the free end of
the bar 23 of the outboard yoke 13. Due to the abovs described
pivotal connection between the free end of the bars 23 and 24,
the pivot pin 27 effectively 3upport~ both bars relative to the
bols~er.
A st~aring crossbar 28 tran~versely extends through
the yo~ bar 23 and ~ centrally pivoted therei~ by the pivot
pin 27. A pair of yoke drag link~ or rods 29 are pivotally
connected at one end to a corresponding end of the ~teering
cros~bar 28 and at the other end to a bracket 30 rigidly depend-
ing ~rom the car body 2~ Each end of the link~ or rod~ 29 lspivotally ¢onnected by a resiliently twistable rod end to allow
restricted twisting a~ well as rotation at each such end. It
must be noted that the inboard end o~ each drag link or rod 29
is pivoted abvut an hori~ontal axi~ to allow for the resilient
~usPenSiOn between the car body and the yokes~ The other or
ou~b~ard end of each drag link i~ pivo~ed about an upright axis
relative to the steerins cros~bar 28.
A pair of side frames 31 and 32 are positioned on
the opposite 3ide~ respeceively of the railway truck and longit-
udinally extend parallel one to the other. Each ~ide framehas its inboard end pivoted at 33 on th~ corrasponding ~ournal
5-
"' :
1, , . , : , ` .. , i . , : , :, :
~ S3~
housing 18 and reRting on a resilient pad 34. Each side frame
has its outboard end resting on a sliding pad 35. Each end
of the bolster 3 rests on a sliding pad 36 at the center of the
correqponding side frame. Thus, the load of the railway car 2
is transmi~ted directly through the air springs 9, and the
opposite ends of the bolster 3 onto the sliding pad~ 36 at the
center of the side frames 31 and 32. The sliding pads 35 and 36
allow relative longitudinally displacement between the journal
bearings 18 or yoke3 13, 14, and between the bolster 3 and the
side frame. Such di~ælacement occurs in a curve upon angular
displacement of th~ car body 2 and bolster 3 therewith relative
to the side frames and the railway truck a~ a whol~. A~ will
be explained later, the angular displacement of th~ truck rel-
ative to the car body steers the yoke 13, 14 to align the
wheel axles 20 radial1y to the curve. Such steering displace- :
ment of the yokes results in relative sliding between the yokes
and t~e side fxames 31, 32 on the ~liding pads 35.
A lateral stabilizinq lin~ or rod 37 extend~ lat-
erally Qf the truck and is pivotally connected to the central
portion of the bolster 3 and to the side fr~me 31. This a~chor
rod or link 3~ accurately restrains the side frame 31 in lateral
directlon. A 5et o three yoke centering links 38, 38, 39 extend
laterally and are pivo~ally connected at one end ~o one end of
a side Erame and at the other end, near the center line of the
correspondin~ yoke. These links 38, 38 and 3~ are provided to
center the side frames 31, 32.
The ste~ring actuation device to actuate the steer
ing crossbar 28 compri~e~ an arm 40 which is fixedly secured
to the central portion 4 of the bolster and extends longitud-
inally of the railway car body 2. Each of this arm 40 and theadjacent draq link ~9 is provided with a qerie~ of adjustmen~
holes 41 ~paced apart alonq the length thereof. An acljustable
~ b
'7~
link 42 i~ pivotally connected in any one of the holes 41. A
stabilizing link 43 is connected paralle!l to and under the
crossbar 28 to stab.ilize the pivot pin through the end o the
cross-bar to resi~t the action thereon by the actuating link 42.
The detailed operation o the railway truck a~embly
will now be explained in details with pzlrticular reference to
Figures 7 and 8. When the railway car is in a curve, the body
2 thereof come~ at an angle "a~ relative to the longitudinal
axis of the railway truck 1. Since th~ bol~ters 3 are res~rain-
ed relative to ~ha ~ar body, they also make the same anglerelative to the truck~ 1.
The reference link 42 act~ ~o keep the ~teering cross-
bar 28 laterally centered with respect to the car body. This
will shift the yoke suf~iciently with respect to the truck
center line to pivot both yokas 13 and 14 in opposite directions
such~*hat both wheel axle~ 20 will take a radial ali~nment
relative to the cur~e.
Although the curvas for a rapid transit ~y~tem are
sharper than tho~s for the conventional railroads, the maximum
steering angle of each wheel axle 20 i8 limited to about 2~
degrees. Fi~ures 7 and 8 are exaqqerating the relative angular
pivoting betwe~n the pivotable component~. In fact, the bars
23 and 24 only slightly ~hit laterally and thus the upright
pivot between the two only slightly ~hits ideway~ ~rom align-
ment with the pivot centar of the truck~ relative to the car
body.
-7-
