Note: Descriptions are shown in the official language in which they were submitted.
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TIIIS I~VENTIO~ relates to bottom discharge hoppers
and, in particular, to hoppers which are an improved form of
the hopper disclosed in Canadian Patent 1,096,239, issued
February 24, 1981.
Because of the problems arising from the discharging
of moist or sludge-like materials from hoppers having a
plurality of relatively narrow openings, there has been a
tendency to use hoppers with single openings in some fields.
Furthermore, recent trends have indicated that single-door
hoppers are preferred in several cases in view of their
definite advantages. However, prior art hoppers known to the
applicant have not completely solved the problems involved
in spite of the tremendous development work in this field.
In Canadian Patent 1,096,239, there is disclosed
in a single-door bottom discharge hopper rail car having
laterally spaced downwardly converging side walls with lon~itu-
dinally extending lower edges defining a discharge openina
from the body. The hopper has a door which is displaceable
between a position in which it closes the opening and a position
in which it is spaced from the opening to permit discharqe of
the contents of the body. The earlier specification discloses
the advantageous feature of providing side walls at different
angles in order to inhibit bridging of materials in the hopper.
In practice, it has been found that this arrangement allows
material initially to slide down the steeper wall. However,
the width of the opening has always had to be less than the
distance between the wheels because material must fall between
the rails in such bottom discharge hoppers. Clearly, material
falling on the aY.le boxes of the hopper rail car, is undesirable
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and can cause considerable damage.
In spite of the considerable improvements provided in
the hopper of Canadian Patent 1,096,239, it was found that
bridging could still occur, particularly with thick sludges
and that the angle of the steeper of the asymmetrical side
walls could not be great enough for some purposes because of
the limitations of the width of the opening.
The applicant therefore re-appraised the problems
involved and has now provided a modified hopper incorporating
the advantages of the hopper in Canadian ~atent 1,096,239
but further reducing the likelihood of brid~ing and facilitating
the speed of discharge.
~he present invention provides a bottom discharge
hopper rail car comprising a hopper body mounted on a chassis
which is itself supported on flanged wheels, the body having a
pair of downwardly convergina, laterally spaced side walls with
longitudinally extending lower edges which border a discharge
B 3
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opening from the body; and a swinging door pivotally mounted
on the body and displaceable between a position in which it is
located below and closes said opening and a position in which
it is to one side of said opening to permit discharge of the
contents of said body; wherein the side walls are asymmetrical
with respect to a longitudinal vertical plane passing centrally
between the wheels, and wherein the lower edges of the side
walls are at a greater lateral distance apart than the wheels.
The wheels may have outer flange surfaces adjacent to
10 rail-engaging surfaces for resting on the rails, and, in order
to be of value in practice, the spacing between the lower edges
of the side walls should be greater than the distance between
these outer flange surfaces. As the spacing increases, the
probability of bridging can be reduced, but the necessary
15 hopper rigidity must, of course, be retained. Thus, the
spacing is preferably at least as great as the distance between
the inner flange surface of one wheel and the outer edge of the
rail-engaging surface of the other wheel. The lower edges may
then be offset from one another in the vertical direction and
20 may be asym~etrical with respect to a central vertical plane
between the wheels in the horizontal direction. For example,
one lower edge may be substantially level with the flanges of
the wheels on the respective side of the hopper, and the other
lower edge may be substantially level with the outer edges of
25 the rail-engaging surfaces of the other wheels. This has the
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tremendous advantage that it enables the wall above said
other lower edge to be relatively steep in order further to
enhance discharge from the hopper without significantly
diminishing the volume of the hopper. For example, the coverging
side wall above that edge may be at an angle of more than 50,
and preferably from 60 to 70 to the horizontal. An upright
wall may extend upwardly from the top of this wall. The other
side of the hopper may have an upright wall spaced from the
respective inclined wall by an intermediate inclined wall
10 so that this side is of progressively decreasing slope as it
approaches the opening.
In practice, the material from the hopper must
normally be discharged between the rails on which the hopper
travels, and for this purpose inclined skirts may be provided
15 to form a chute for guiding the material between the rails.
The skirts may converge to such an extent that the distance
between their lower edges is substantially equal to the lateral
distance between the wheels so that the skirts do not unduly
inhibit free flow of the material. Although the opening between
20 the lower edges of the skirts is thus not significantly greater
than the normal hopper discharge opening, it will be realised
that the material being discharged from the hopper has already
gathered momentum by the time it reaches this restriction
and bridging is unlikely.
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For a better understanding of the present invention,
reference will now be made, by way of example, to the accom-
panying drawings, in which:
Figure 1 is a side elevation of a bottom discharge hopper
car; and
Figure 2 is a sectional end elevation of the hopper car of
Figure 1.
The hopper car illustrated in Figures 1 and 2 is
generally referenced 10 and comprises a chassis 12, a hopper
10 body 14, and a door 16.
The chassis 12 includes two sets of wheel bearings 18
which mount flanged wheels 20 having rail-engaging surfaces
laterally outwardly of their flanges. A series of supports 22
extend upwardly from a frame which forms a major part of the
15 chassis 12 and which is itself constituted by a longitudinal
beam 24 and longitudinal and transverse I-beams 26. The
supports 22 are welded to the longitudinal beam 24.
The body 14 comprises laterally spaced sidewalls 28
and 30 fixed on the chassis 12, and two end walls 32. The
20 sidewall 28 comprises a sloping wall 34 sloping upwardly from a
lower longitudinal edge 36 and a vertical wall 38 extending
upwardly from the sloping wall 34. The sidewall 30 has a
vertical wall 40 which is parallel to, and spaced laterally
from, the vertical wall 38, a further sloping wall 42, and an
25 intermediate wall 44 which is between the walls 40 and 42 and
)6
is inclined at a relatively steep angle compared to the wall
42. The walls can be strengthened by suitable stiffeners,
where necessary.
As will be clearly understood from the following
description, the door 16 swings between the positions illu~-
trated at 16.1 and 16.2 in Figure 2. To permit this movement
to take place, while still providing some support for the
hopper body on this side of the car, two vertically elongated
supports 46 of I-section are provided. The supports 46 extend
10 between the transverse I-beams 26 of the frame 14 and are
secured to the walls 32.
The door 16 comprises two approximately triangular
end plates SO which are carried pendulum fashion by overhead
pivot structures 52. The o~erhead pivot structures 52 mount
15 the end plates 50 on the end walls 32 of the hopper body 14.
The door 16 further includes a curved base plate 54
(the concave face of the base plate being uppermost) which
extends between and is secured to the end plates 50. The base
plate 54 is strengthened by a pair of channels 56 which extend
20 downwardly from the underside thereof. One of the longitudinal
edges 55 of the base plate 54 is turned downwardly which also
enhances its strength.
Centrally of the door, i.e. midway between the plates
50, the door is provieed with two curved, parallel, transverse-
ly extending stiffeners 58. A pivot pin 60 is mounted on the
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stiffeners 58 and the pin 60 pivotally mounts an arm 62. The
arm has a roller 64 rotatably mounted at the outer end thereof.
The upper face of the arm 62 is shown at 66 and it
will be seen that this, in the closed position of the door, is
spaced from the turned-down longitudinal edge 55 which lies
thereabove. The lower side of the edge 55 constitutes an
abutment surface of the door and the co-operating portion of
the arm constitutes an abutment face on the arm. When the
outer end of the arm 62 is lifted upon the roller 64 encounter-
10 ing a ramp there is some lost motion between the arm 62 and thedoor 16. More specifically, the arm 62 lifts, pivoting about
the pin 60 with respect to the door 16, until the gap between
this turned-down edge 55 and the arm has been taken up.
Thereafter, further swinging movement of the arm 62 in an
15 upward direction towards the position 16.2 shown in Figure 2
causes the door 16 to lift. It will be noted that in this
position the arm 62 is in engagement with the turned-down edge
55. Discharge of the material in the hopper body then takes
place, the material sliding downwardly over the walls 34 and 42
20 and through the rectangular frame constituted by the channel 24
and I-beams 26.
The arm 62 has a stepped undersurface provided with a
wedge plate 68 for engaging a complementary wedge plate 70 on
the I-beam 26 in the closed condition of the door.
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g
As will be seen from Figure 2, the wedge plate 68
engages the wedge plate 70 of the longitudinal I-beam 26 so
that, in the closed condition of the door, lateral movement of
the arm and door towards the open position is prevented.
During the upward lost motion of the arm 62 with respect to the
base plate 54, the wedge plate 68 clears the wedge plate 70.
Consequently, by the time the arm engages and commences to lift
the door in its outward swinging movement, the wedge plates are
clear of one another and as a consequence, do not hinder such
10 movement.
During the closing movement of the door, the door and
arm swing downwardly together until the door reaches its full~
closed position. Thereafter the arm moves downwardly away from
the door and the wedge plates re-engage. Downward movement of
15 the arm 62 ceases when the wedge plates are located firmly
against one another.
The axis of rotation of the roller 64 in its initial
door pivoting position, is shown at X in Figure 2 and it will
be seen that this passes through the common axis of the pivot
20 structures 52. It naturally continues to pass through this
axis as the door pivots. The curved base plate 54 of the door
16 is ~enerated about a longitudinal axis Y slightly to the
right of the common axis of the pivot structures 52 in Figure
Z.
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-10-
By off-setting the axis Y horizontally from the
common axis of the pivot structures 52, the motion imparted to
the door 16, while being a true pendulum motion, includes a
downward component with respect to the stationary parts of the
5 hopper. This means that those portions of the door which are
in sealing engagement with the lower edges of the walls 34 and
42 of the hopper body do not simply swing laterally with
respect thereto. Instead, said portiolls simultaneously swing
laterally and move downwardly with respect to said stationary
10parts so that gaps of progressively increasing width are
created. This can thus reduce the possibility of ore wedging
the door solidly to the body and can thereby help to prevent
the car being tipped over by the ramp.
The sloping walls 34 and 42 are asymmetrically
15arranged with respect to one another insofar as their angles of
slope are concerned and/or insofar as the disposition of their
upper and lower edges in the horizontal plane is concerned.
More specifically, the two walls slope at different angles and
the horizontal plane containing the convergence between the
20walls 34 and 38 is at a different vertical level to the
horizontal plane containing the convergence between the walls
40 and 44 or 42 and 44. The side wall 34 is at a relatively
steep angle of about 70 to the horizontal. The lower edges of
the walls 42 and 34 are in a different plane. By means of this
25asymmetrical arrangement of the walls, it is possible to reduce
the tendency of material contained in the hopper body to
'bridge' when efforts are made to discharge it, as compared
with many alternative hoppers.
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The lower edge 36 of the inclined sidewall 34 and the
lower edge 74 of the inclined sidewall 42 are spaced apart at a
distance A which is greater than the distance B between the
wheels 20. The distance A is, in fact, about equal to the
distance between the outer edge of the rail-engaging surface of
one wheel and the outer edge of the flange of the other wheel
on the same axle. The provision of the wide opening in
combination with the steep side ~all 34 can further help to
ensure that the material in the hopper, particularly muddy
10 material, will not form a hridge over the hopper opening when
the door opens, as can often happen with many conventional
hoppers.
In order to ensure that material passing through the
hopper opening is inhibited from falling outside the rails on
15 which the hopper runs, inclined skirt plates 76 are provided to
form a chute for guiding material falling from the hopper
between the rails. The skirt plates have laterally outer parts
converging from locations outwardly of the opening substantial-
ly to the planes of the wheel flanges. The plates also have
20 relatively steep inner parts converging to a gap of width B,
which is equal to the distance between the wheels. Although
the skirt plates are much closer together in the region of the
gap than are the sidewalls 34 and 42, material falling from the
hopper does not form a bridge over the space between the skirt
25 plates in this region because the material has already
developed sufficient momentum to prevent this b-, the time it
reaches the skirt plates.
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-12-
The skirt plates are cut away or modified to provide
clearance for the wheels of the vehicle and the wheel arches
thus formed can be strengthened by welding on arched elements
in the region 80.
As will be seen from Figure l, the upper ends of the
end walls 32 of the hopper body 14 may be provided with
diverging guide w~lls 82 and 84 which constitute overhanging
portions of the body. The guide wall 82 slopes at an angle of
less than 45 degrees and terminates in a downwardly directed
10 lip 86. The wall 84 slopes at about 45 degrees and also
terminates in a lip 88. The walls 82 and 84 are such that,
when two hopper cars are coupled end-to-end in a train, the
wall 84 and its lip 88 overhang the wall 82 and its lip 86.
Thus, when the car is filled while moving under a continuous
15 discharge or ore or the like, the overhanging walls 82 and 84
ensure that material cannot be dumped between the cars onto the
track.
When the hopper cars negotiate a bend in the track,
the laterally outer ends of the wall 82 move one forwardly and
20 one rearwardly with respect to the overhanging wal.l 84. To
prevent engagement of the wall 82 with the wall 84, the end
portions of the wall 84 are formed with vee-shaped notches 90.
With this arrangement the ends of the wall 82 swing into these
notches so that the train can round the bend safely without any
25Of the trucks being derailed.
