Note: Descriptions are shown in the official language in which they were submitted.
CA 02530103 2008-11-26
ENCLOSED RAILCAR JACK ASSEMBLY
TECHNICAL FIELD
[0002] The present invention relates to the field of lifting devices, and more
particularly to a railcar jack assembly.
BACKGROUND OF THE INVENTION
100031 A typical railcar has an elongated frame and a pair of wheeled truck
assemblies attached to the frame. Each truck assembly is attached to the frame
at
each end of the railcar. Each wheeled truck assembly in turn includes flanged
wheels that are adapted to roll on a pair of railroad track rails.
[00041 With the wheels on the railroad track rails, there may be clearance of
only a few inches between the top of the rails and the underside of the
railcar
frame. Routine maintenance may require that the railcar frame be elevated
somewhat in order to increase this clearance so that the underside of the
frame
may be serviced. One form of maintenance may require that the railcar be
completely removed from one of the truck assemblies, to allow such truck
assembly to be replaced or serviced. For example, to remove the assembly, the
one end of the railcar may be lifted vertically about 10-30 inches, while the
other
end of the railcar remains supported on the other wheeled truck assembly. With
the one railcar end so elevated, both old and new truck assemblies can be
rolled
along the rails.
[00051 One way of lifting one end of the railcar is by means of a crane. This
is
done by connecting the lift line of the crane to the railcar frame, such as at
the
railcar coupling. This requires the presence of a high capacity crane that can
carry
the load of the railcar, and such a crane will typically be quite large and
represent a
significant capital investment. Moreover, such a crane may be mounted on a
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special railroad service railcar or road vehicle. If the crane is limited to
rolling
along on track rails, it may not be conveniently moved from one site to
another. If
the crane is on a road vehicle, the crane may be used only at certain rail
sites
because of its size.
100061 Another way the railcar can be removed from the wheeled truck
assembly is by means of a pair of separate lift jacks, interposed between the
underlying rail bed and each side of the railcar frame. These jacks are
relatively
inexpensive and quite portable. However, as the separate jacks bear against
the
rail bed, special shoring efforts may be needed in order to provide added
stability
to the jacks and to prevent the jacks from sinking into the rail bed.
Moreover, with
the jacks on opposite sides of the railcar, several people may be needed to
operate
thejacks.
[0007] One example of a railcar jack assembly is described in United States
Patent Application No. 10/404,00 1, entitled "Center Sill Car Jack Utilizing
Air
Bellows" filed on March 31, 2003 and issued as United States Patent No.
6,926;256.
The jack assembly in such application incorporates a set of bellows to raise a
car-engaging means that, in turn, lifts the railcar above a wheeled truck
assembly.
[0008] Moreover, there are certain inherent risks with the use of either the
crane or paired lifl jacks because they bear the entire load of the railcar
during the
time the wheeled truck is removed from the railcar or while someone is under
the
railcar for servicing. A crosswind may cause the crane-suspended railcar to
sway,
or the paired jack-supported railcar may topple sideways off of the jacks.
This can
be both dangerous to personnel and destructive to property. Dangerously, any
failure of the crane lift line or of either jack can allow the raised railcar
to fall.
BRIEF SUMMARY
[0009) The present invention provides an apparatus and method for raising and
lowering a railcar.
[0010] In one aspect of the invention, a jack assembly is provided. The jack
assembly includes a pair of spaced-apart frame rails. The jack assembly also
includes a power unit that is operatively attached to the frame rails. The
power
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unit is configured to actuate a first lifting mechanism and a second lifting
mechanism. The first lifting mechanism is spaced apart from the second lifting
mechanism. The jack assembly further includes a railcar engaging mechanism
that is operatively connected to the first and second lifting mechanisms.
[OOlOa] In another aspect of the invention, a jack assembly is provided. The
jack assembly includes a pair of spaced apart parallel frame rails. The jack
assembly also includes a rotatable first lifting mechanism operatively
connected to
at least one of the frame rails and a second lifting mechanism operatively
connected to at least one of the frame rails. The jack assembly also includes
a
railcar engaging member extending at least partially between the first lifting
mechanism and the second lifting mechanism, and a power unit located adjacent
to one of the lifting mechanisms. The power unit is attached to both of the
spaced
apart frame rails and is configured to actuate the lifting mechanisms.
[OOlOb] In another aspect of the invention, a jack assembly is provided. The
jack assembly includes a pair of spaced apart parallel frame rails. The jack
assembly also includes a rotatable first lifting mechanism operatively
connected to
at least one of the frame rails and a second lifting mechanism operatively
connected to at least one of the frame rails. The second lifting mechanism
includes a fixed mast and a moving mast. The jack assembly also includes a
railcar engaging member extending at least partially between the first lifting
mechanism and the second lifting mechanism, and a power unit located adjacent
to the second lifting mechanism. The power unit is attached to the fixed mast
of
the second lifting mechanism and both of the spaced apart frame rails and is
configured to actuate the first and the second lifting mechanisms.
[OOlOc] In another aspect of the invention, a method of elevating a railcar
above a pair of railroad track rails is provided. The method includes
providing a
jack assembly having a pair of spaced apart parallel frame rails, a power unit
attached to both of the spaced apart frame rails, a first lifting mechanism, a
second
lifting mechanism spaced apart from the first lifting mechanism, and a
railcar-engaging member operatively connected to the first and second lifting
mechanisms. The method also includes applying hydraulic pressure to the first
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and second lifting mechanisms. The hydraulic pressure activates the first and
second lifting mechanisms, thereby causing the first and second lifting
mechanisms and the railcar-engaging section to move together between a first
position and a second position.
100111 Advantages of the present iiivention will become more apparent to
those skilled in the art from the following description of the preferred
embodiments of the invention which have been shown and described by way of
illustration. As will be realized, the invention is capable of other and
different
embodiments, and its details are capable of modification in various respects.
Accordingly, the drawings and description are to be regarded as illustrative
in
nature and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
100121 Figure 1 is a top view of an embodiment of a center sill rail car with
a
jack assembly of the present invention in an operative position;
[0013) Figure 2 is a side view of the center sill railcar of Figure 1 with the
jack
assembly in an operative position;
[0014) Figure 3 is a side view of a double stack railcar with a jack assembly
in
an operative position;
[0015) Figure 3A is a cross-sectional view of the double stack railcar of
Figure
3 taken along the line 3A-3A;
[0016] Figure 4 is a top perspective view of an embodiment of a jack assembly
of the present invention;
[00171 Figure 5 is an exploded top perspective view of the car engaging
section thereof;
[0018] Figure 6A is a side view of a jack assembly in an operative position;
[0019) Figure 6B is a side view of a jack assembly in which the tilt arm is
between a raised and lowered position;
[0020) Figure 6C is a side view of a jack assembly in which the tilt arm is in
a
generally vertical, or raised position;
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100211 Figure 61) is a side view of a jack assembly in which the lifting
mechanisms and the car-engaging inember liave been raised;
[0022] Figure 7 is a top perspective view of a fixed mast assembly;
[0023] Figure 8 is a top perspective view of a moving mast asseinbly;
[0024] Figure 9A is a front view of a lifting mechanism in which the top plate
has been removed;
100251 Figure 9B is a cross-sectional view of a fixed mast side member and a
moving mast side rail taken along line 9B-9B of Figure 9A;
[0026] Figure 10 is a front view of a lifting mechanism in a raised position
in
which the top plate has been removed;
[0027] Figure 11 A is a cross-sectional view of a safety bar locking device in
a
locked position;
[0028] Figure 11B is a cross-sectional view of a safety bar locking device in
an
unlocked position;
[0029] Figure 12A is a side view of a connection between the tilt arm and
railcar-engaging section wherein the tilt arm is in an operative position;
[0030] Figure 12B is a side view of a connection between the tilt arm and
railcar-engaging section wherein the tilt arm is at an angled position;
[0031] Figure 12C is a side view of a connection between the tilt arm and
railcar-engaging section wherein the tilt arm is in a vertical position; and,
[0032] Figure 12D is a top perspective view of the connection between the tilt
arm and the railcar engaging section, wherein a portion of the top plate is
removed.
DETAILED DESCRIPTION OF THE DRAWINGS AND THE
PRESENTLY PREFERRED EMBODIMENTS
[0033] FIG. I is a top view of one embodiment of an enclosed railcar jack
assembly 41 in a preferred operative position beneath a center sill railcar
12. A
section of railcar flooring 14 has been cut away to show the location of a
wheeled
truck assembly 16 with respect to the railcar frame and the railroad track
rails.
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[0034] In a first exemplary embodimenl, a flat-bed railcar 12 has flanged
wheels 21 adapted to roll on two late--ally spaced track rails 20, as
illustrated in
FIGS. I and 2. "I'he railcar 12 has a frame 18 including a central sill 22 and
side
channels 23, each elongated in the direction of the track rails 20. A wheeled
truck
assembly 16 is connected to the central sill 22 of the frame 18 at each end of
the
railcar 12. Couplings 24 are connected to the frame 18 at the opposite ends of
the
railcar 12.
100351 In a second exemplary embodiment, a double stack railcar 13 includes a
frame 15 formed with a pair of bottom corner angles 132 arranged such that one
surface of the corner angle 132 is directed vertically and the second leg of
the
corner angle 132 is directed toward the opposing corner angle, as illustrated
in
FIGS. 3 and 3A. The corner angles 132 are elongated in the direction of the
track
rails 20. A cross plate 138 connects the opposing corner angles 132 in order
to
form the lower portion of the railcar frame 15. A side sill 136 extends
vertically
from the upwardly-directed leg of the corner angle 132, and a hollow square
tube
130 is connected at the top of the side sill 136. The jack assembly 41 is
configured to fit between the track rails 20 and the frame of most railcars.
[0036] As illustrated in FIGS. 1 and 2, each wheeled truck assembly 16
includes a cross member 25 and a pair of side frame members 26. The cross
member 25 is coupled at its ends through spring and snubbing means (not shown)
to the side frame members 26. One flanged wheel 21 is fixed adjacent each end
of
axle 27, and two such axles 27 are mounted in bearings (not shown) carried in
the
opposite respective side frames 26.
[0037] A typical railcar 12 may be approximately ten feet wide, across the
exterior of its side sections or flooring 14. The railcar 12 rides centered
relative
the track rails 20, which conventionally may be separated by approximately
four
and one-half feet. With the wheels 21 on the track rails 20, there may be only
about 10 inches of vertical clearance between the tops of the track rails 20
and the
underside of the railcar frame 18 at the central sill 22.
[0038] The jack assembly 41, to be discussed further herein, may be used to
lift
the railcar frame 18. For example, the railcar frame 18 may be lifted
completely
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otf of a single wheeled truck assembly 16, as shown in phantom lines in FIGS.
2
and 3. "I,hejack assembly 41 is placed between the wheeled truck asseinblies
16,
usually closer to one wheeled truck assembly 16 while still being able to
engage
the frame 18 of the railcar. The operative position of the jack assembly 41 is
preferably where the railcar-engaging section 44 is disposed between the
central
sill 22, or the frame, of the railcar and the track rails 20. In the operative
position,
the railcar-engaging member 29 can engage the frame 18 and lift the frame 18
to a
position spaced above the wheeled truck assembly 16 while the frame 18 remains
supported on the opposite wheeled truck assembly 16. Each wheeled truck
assembly 16 is self-contained, and can be easily connected to or separated
from
the railcar 12.
[0039] As illustrated in FIG. 4, the jack assembly 41 includes four distinct
operational areas: a power unit 42, a railcar-engaging section 44, and a pair
of
enclosed lifting mechanisms 45, 46 located at opposing ends of the railcar-
engaging section 44. The power unit 42 is located within a housing 48 disposed
at
the end of the jack assembly 41 opposite the tilt arm 50. The first lifting
mechanism 45 is located adjacent to the power unit 42. The housing 48 and the
first lifting mechanism 45 are preferably disposed atop the frame rails 30 of
the
railcar-engaging section 44. The first lifting mechanism 45 remains in the
vertical
orientation at all times while the tilt arm 50 is rotatable between horizontal
and
vertical positions. The tilt arm 50 encompasses a second lifting mechanism 46
and
includes attachments, which will be described below, to connect the tilt arm
50 to
the railcar-engaging section 44. The railcar-engaging section 44 is configured
to
rest atop the track rails 20 and engage the frame 18 of the railcar 12 when
the
lifting mechanisms 45, 46 of the jack assembly 41 are raised. The tilt arm 50
is
configured to be in a substantially horizontal position when being placed
beneath
or removed from below the railcar 12.
[0040] Each lifting mechanism 45, 46 of the jack assembly 41 includes a fixed
mast 52 and a moving mast 54, as illustrated in FIGS. 7 and 8, respectively.
FIG.
7 illustrates one embodiment of a fixed mast 52. The fixed mast 52 includes a
pair
of generally parallel, spaced-apart side members 56. The side members 56 have
a
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first distal end 57, a second distal end 58, and a c-shaped cross section.
"I'he c-
shaped cross section includes a top edge 59, a bottom edge 60, and a flange 61
that
connects the top and bottom edges 59, 60, as illustrated in FIG. 9B. The side
inembers 56 are oriented such that the c-shaped cross-sections are directed
inward
toward each other. The side members 56 are oriented such that the c-shaped
cross
section of each side member 56 is directed toward opposing side member 56 of
the
fixed mast 52. The side members 56 act as guides to control the movement of
the
moving mast 54 as well as provide the side surfaces for an enclosed lifting
mechanism 45, 46. As shown in FIG. 7, a portion of the top edge 59 of each
side
member 56 is removed at the second distal end 58, and a roller 62 is coupled
to the
inward-facing surface of the flange 61 at a location within the area removed
from
the top edge 59. The roller 62 coupled to the flange 61 is configured to
provide a
rolling engagement between the fixed mast 52 and the moving mast 54.
100411 The first lifting mechanism 45, the tilt arm 50, and the power unit 42
are connected by the railcar-engaging section 44, as illustrated in FIG. 4. In
one
embodiment, the railcar-engaging section 44 includes a pair of generally
parallel,
spaced-apart frame rails 30, a base plate 39, a railcar-engaging member 29,
and
conduits 40 for the electrical and hydraulic connections, as illustrated in
FIG. 5.
The railcar-engaging section 44 is configured to be located between the frame
of a
railcar and the railroad track rails 20, wherein the frame rails 30 and the
base plate
39 of the jack assembly 41 rest upon the top surfaces of the track rails 20 in
a
substantially perpendicular relationship. The vertical height H of the railcar-
engaging section 44 and the tilt arm 50, as illustrated in FIG. 6A, is about
15.2-
16.5 cm (6-6'/2 in.). However, it should be understood by one skilled in the
art that
the height H can be of any length sufficient to allow the railcar jack to be
disposed
between track rails and the frame of a railcar. The height H of the railcar-
engaging section 44 and the tilt arm 50 is such that the jack assembly 41 can
be
disposed between the railroad track rails and the lowermost portion of the
frame of
nearly all conventional railcars. In addition, the hydraulic cylinders 74 of
the
lifting mechanisms 45, 46 provide an operative stroke sufficient to lift the
frame of
nearly all conventional railcars including, but not limited to, center sill
and double
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stack railcars. The capability of the enclosed jack assembly 41 to be operated
in
conjunction with nearly all raiicars provides an advantage over other jack
assemblies that are usually configured to be used with a particular railcar.
[0042] In one embodiment, the frame rails 30 are hollow tubes, as illustrated
in
FIG. 5, having a generally square cross-section in order to provide fork
pockets
located at the ends of the frame rails 30 adjacent to the power unit 42. The
fork
pockets allow for the forks of a forklift to be inserted into the hollow frame
rails
30. The use of a forklift to lift and move the jack assembly 41 allows
provides
great mobility of the jack assembly 41 between locations. In an alternative
embodiment, the frame rails are solid rods, and have a hollow tube attached to
the
end of the solid frame rails opposite the tilt arm, thereby creating the fork
pockets.
It should be understood by one skilled in the art that the frame rails can be
formed
of any shape or size that is sufficient to withstand the loadings of a
railcar.
[0043] The bottom surface of the opposing frame rails 30 are attached to the
top surface of a base plate 39, whereby a seat is created for the railcar-
engaging
member 29 and plate supports 122, as illustrated in FIG. 5. In one embodiment,
conduits 40 for the electrical and hydraulic connections are located within
the seat
formed by the base plate 39 and the frame rails 30. Each conduit 40 is formed
with an conduit member that connects the upper corner on the inner surface of
a
frame rail 30 to a line along the top surface of the base plate 39 located a
distance
of about 10.5 cm (4 in.) toward the longitudinal centerline of the railcar-
engaging
section 44. The conduit 40 is a triangular hollow passage, and allows for the
electrical wiring and hydraulic tubing to be passed from the power unit 42 to
the
tilt arm 50 without interference from the railcar-engaging member 29 or the
plate
supports 122. In an alternative embodiment, one conduit is disposed within the
seat of the railcar-engaging section 44 to carry only the electrical wiring
and
another conduit to only carry the hydraulic lines. It should be understood by
one
skilled in the art that any number of conduits can be used, and the conduit 40
can
be of any shape sufficient to transfer the electrical wiring and hydraulic
lines from
the power unit to the tilt arm 50.
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10044] In one embodiment, the railcar-engaging meniber 29 and plate supports
122 are disposed witliin the seat created by the frame rails 30, conduits 40,
and the
base plate 39, as illustrated in the exploded view of FIG. 5. A trunnion 38 is
attached to both opposing ends of the plate supports 122 and the railcar-
engaging
member 29 for connection with the knuckle links 36 so that the moving masts 54
of the opposing lifting mechanisms 45, 46 are operatively connected to the
railcar-
engaging member 29. The plate supports 122 are elongated hollow tubes having a
generally square cross-section. It will be understood by one skilled in the
art that
the plate supports 22 can be of any shape or size sufficient to provide
structural
support to the railcar-engaging member 29 and provide an attachment for the
trunnions 38 The plate supports 122 are welded together to provide a structure
that can withstand the bending loads applied from the railcar 12. The railcar-
engaging member 29 is in tum welded to the top surface of the plate supports
122.
The width of the railcar-engaging member 29 is less than the seat created by
the
frame rails 30 and the base plate 39 such that at least one conduit can be
disposed
between the railcar-engaging member 29 and plate supports 122 and the frame
rails 30.
[0045] In the illustrated embodiment of FIG. 4, the power unit 42 is rotatably
connected to the fixed mast 52 of the first lifting mechanism 45. In an
alternative
embodiment, the housing of the power unit is welded to the top surface of the
opposing frame rails at the distal end opposite the tilt arm, adjacent to, but
not
attached to, the fixed mast 52 of the first lifting mechanism 45. The power
unit 42
is encased by the housing 48 in order to prevent damage to the components
during
transportation from one location to another. The power unit 42 is configured
to
control the entire operation of the jack assembly 41. The housing 48 of the
power
unit 42 is rotatable between an open and a closed position. When in a closed
position, the user cannot activate the power unit 42, thereby preventing
activation
of the jack assembly 41 when the housing is closed. The power unit 42 can
include components such as a motor, a hydraulic pump, hydraulic system valves,
electrical system, and a control pendant. The motor provides power to the
hydraulic pump in order to operate the hydraulic cylinders used to raise and
lower
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the lifting mechanisms and railcar-engaging member. A control pendant is
attached to a cord that is in tui-n connected to the electrical system in
order to
allow the user to control the motion of the jack assembly 41. In one
embodiment,
the control pendant includes depressable "up" and "down" buttons, whereby the
various movements of the jack assembly 41 are controlled by the buttons. ln an
alternative embodiment, a control panel is attached to the housing of the
power
unit. The control panel includes at least one lever that controls the various
motions of the tilt arm and the lifling mechanisms.
10046] As illustrated in FIG. 7, a bottom plate 63 is connected to the inner
surfaces of the opposing bottom edges 60 of the side members 56 of the fixed
mast
52. The bottom plate 63 is preferably welded to the side members 56, but it
should be understood by one skilled in the art that any other means of
attaching
the bottom plate 63 to the side members 56 sufficient to withstand the
transportation and operation of the jack assembly 41 can be used. The bottom
edge 64 of the bottom plate 63 corresponds to the first distal end 57 of the
side
members 56, and the top edge 65 of the bottom plate 63 corresponds to the
second
distal end 58 of the side members 56. The bottom plate 63 provides a third
outer
surface for an enclosed lifting mechanism 45, 46.
100471 The fixed mast 52 also includes a safety bar guide 66 attached to the
bottom plate 63, and the safety bar guide 66 is configured to guide the
ratchet
safety bar 68 as the moving mast 54 is raised and lowered with respect to the
fixed
mast 52, as shown in FIGS. 9A and 10. FIG. 7 illustrates the safety bar guide
66
preferably welded to the bottom plate 63, but it should be understood by one
skilled in the art that any other means of attaching the safety bar guide 66
to the
fixed mast 52 sufficient to withstand the transportation and operation of the
jack
assembly 41 can be used. The safety bar guide 66 is an inverted u-shaped
mechanism that includes a top member 69 that is oriented generally
perpendicular
to the side members 56 of the fixed mast 52 and two angled members 70
extending from the top member 69 in a generally parallel relationship to the
side
members 56. The angled members 70 extend from the top member 69 in a
perpendicular manner such that the height of the angled members 70 decreases
as
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ihe angled members 70 extend away from the top member 69. The top member 69
of the safety bar guide 66 is located centrally between the side members 56 of
the
fixed mast 52 near the top edge 65 of the bottom plate 63, and the angled
members
70 extend therefrom toward the bottom edge 64 of the bottom plate 63. The top
member 69 includes a slot (not shown) that is elongated in the longitudinal
direction of the top member 69. The slot allows the safety bar 68 to pass
through
the safety bar guide 66, as shown in FIG. 9A.
10048] A pair of lower cylinder supports 72 are attached to the bottom plate
63
of the fixed mast 52 to provide foundational support for the hydraulic lift
cylinders
74, as shown in FIG. 7. Each lower cylinder support 72 includes a lower base
member 75, a pair of spaced-apart lower bearing members 76, and a lower
support
pivot 77. The lower base member 75 is positioned at the first distal end 57 of
each
side member 56 of the fixed mast 52 and is oriented substantially
perpendicular to
the side members 56. Each lower base member 75 is preferably welded to the
bottom edge 64 of the bottom plate 63 and to the end surface of an adjacent
side
member 56. One surface of each lower bearing member 76 is welded to the lower
base member 75 and another surface is welded to the bottom plate 63 at a
substantially perpendicular orientation. The lower bearing members 76 extend
from the lower base member 75 toward the top edge 65 of the bottom plate 63 in
a
manner generally parallel with the side members 56. Each of the lower bearing
members 76 includes a hole through which a lower support pivot 77 is passed in
a
generally normal orientation. The base mounting 78 of a hydraulic cylinder 74
is
disposed between a pair of lower bearing members 76, wherein the lower support
pivot 77 passes through the hole of one lower bearing member 76, through the
holes of the base mounting 78 of the hydraulic cylinder 74, and then through
the
hole of the second lower bearing member 76. The hydraulic cylinders 74 are
thereby grounded to the fixed mast 52 through the lower cylinder supports 72,
and
are attached to the moving mast 54 through a similar pair of upper cylinder
supports 1] 2.
(0049] In addition to the fixed mast 52, each lifting mechanism 45, 46 of the
jack assembly 41 includes a moving mast 54. As illustrated in FIG. 8, the
moving
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mast 54 includes a pair of generally parallel, spaced-apart side rails 80. The
side
rails 80 have a t7rst distal end 81, a second distal end 82, and a c-shaped
cross
section. The c-shaped ci-oss section includes a top edge 83, a bottom edge 84,
and
a flange 85 that connects the top and bottom edges 83, 84, as illustrated in
FIG.
9B. The side rails 80 are oriented such that the c-shaped cross-sections are
directed outwardly away from each other. When the lifting mechanisms 45, 46
are
fully constructed, the first distal ends 81 of the moving mast side rails 80
are
immediately adjacent to the first distal ends 57 of the fixed mast side
members 56,
and the second distal ends of 82 the moving mast side rails 80 are immediately
adjacent to the second distal ends 58 of the fixed mast side members 56.
100501 A portion of the bottom edge 84 of each side rail 80 is removed at the
first distal end 81, and a roller 62 is attached to the outward-facing surface
of the
flange 85 at a location within the area removed from the bottom edge 84, as
shown
in FIG. 8. The rollers 62 attached to the flanges 85 of the moving mast side
rails
80 are configured to be disposed between the top and bottom edges 59, 60 of
the
fixed mast side members 56, and the rollers 62 attached to the flanges 61 of
the
fixed mast side members 56 are likewise configured to be disposed between the
top and bottom edges 83, 84 of the moving mast side rails 80, as illustrated
in FIG.
9B. The diameter of the rollers 62 is slightly smaller than distance between
the
top 59, 83 and bottom edges 60, 84 of the corresponding side rails 80 or side
members 56. It should be understood by one skilled in the art that the
diameter of
the rollers 62 must be sufficient to achieve a sliding relationship between
the
moving and fixed masts 54, 52 without allowing direct frictional contact
between
the fixed mast side members 56 and the moving mast side rails 80.
100511 As illustrated in FIG. 8, a top plate 86 is attached to the opposing
side
rails 80 of the moving mast 54 by connecting the inner surface of the top edge
83
of the side rails 80. The top plate 86 is preferably welded to the side rails
80, but
it should be understood by one skilled in the art that any other means of
attaching
the top plate 86 to the side rails 80 sufficient to withstand the
transportation and
operation of the jack assembly 41 can be used. The bottom edge 87 of the top
plate 86 is associated with the first distal end 81 of the side rails 80, and
the top
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edge 88 of the top plate 86 is associated with the second distal end 82 of the
side
rails 80. The top plate 86 pi-ovides a fourth outer surface for an enclosed
lifting
mechanism 45, 46.
10052] As shown in FIG. 8, a safety bar support 90 is attached to the top
plate
86 of the moving mast 54, and is configured to stabilize the lower portion of
the
ratcheted safety bar 68. The safety bar support 90 is preferably welded to the
top
plate 86, but it should be understood by one skilled in the art that any means
of
connecting the safety bar support 90 to the top plate 86 sufficient to
withstand the
transportation and operation of the jack assembly 41 can be used. The safety
bar
support 90 is centrally disposed between the opposing side rails 80 of the
moving
mast 54. The safety bar support 90 includes a pair of spaced-apart, elongated
braces 91 that are elongated in a generally parallel orientation with respect
to the
side rails 80. The braces 91 are spaced apart by a distance greater than the
width
of the ratcheted safety bar 68. An elongated edge of each brace 91 is attached
to
the inward-facing surface of the top plate 86. Another edge of each brace 91
is
generally aligned in a coplanar manner with the bottom edge 87 of the top
plate
86. The braces 91 are operatively coupled to each other by way of a cross beam
92. The cross beam 92 and braces 91 form a hollow box-like structure with the
top plate 86. The lower portion of the ratcheted safety bar 68 is attached to
the
safety bar support 90 preferably with a four-bolt pattern. It should be
understood
by one skilled in the art that the safety bar 68 can be attached to the safety
bar
support 90 by any other means sufficient to withstand the operation and
transportation of the jack assembly 41.
100531 The ratcheted safety bar 68 is attached to the moving mast 54 at both
the top and bottom distal ends of the safety bar 68, wherein the middle
portion of
the safety bar 68 is disposed within a slot in the top member 69 of the safety
bar
guide 66 attached to the fixed mast 52. The size of the slot is sufficient to
allow
the entire width of the ratcheted safety bar 68 to easily pass through during
the
raising and lowering of the lifting mechanisms 45, 46. One end of the
ratcheted
safety bar 68 is attached to the safety bar support 90, and the opposing end
is
connected to the loading member 110 of the moving mast 54. The lengtli of the
CA 02530103 2005-12-14
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ratcheted safety bar 68 is oriented in a substantially parallel relation with
the
longitudinal axes of the moving mast side i-ails 80.
100541 The edges of the i-atcheted safety bar 68 form a rack 94 such that the
rack 94 corresponds with the safety pins 102 of the safety bar locking
inechanism
100, as illustrated in FIGS. I 1 A-1 I B, thereby forming a rack-and-pinion
relationship as explained later. The ratcheted safety bar 68 is configured to
be
connected to the moving mast 54 so as to prevent an unexpected or sudden drop
of
the railcar 12 as the railcar 12 is being lifted or lowered by the jack
assembly 41.
For example, when the lifting mechanisms 45, 46 are acting in conjunction with
the railcar-engaging member 29 to raise a railcar 12 and the power unit 42
fails, or
if there is otherwise loss of hydraulic pressure, the rack-and-pinion safety
bar
locking mechanism 100 prevents the railcar 12 from crashing down.
[0055] The safety bar 68 acts in conjunction with the safety bar locking
mechanism 100 attached to a central portion of the top member 69 of the safety
bar guide 66 on the fixed mast 52 as the lifting mechanisms 45, 46 are raised
and
lowered, as illustrated in FIGS. 9A-11B. In one embodiment, as illustrated in
FIGS. 7, 11 A and 11 B, the safety bar locking mechanism 100 includes an
opposing, generally parallel pair of locking beams 104, a pair of safety pins
102,
two pairs of die springs 106 and two pistons 108. The pair of locking beams
104
are preferably hollow tubes having a generally square cross section. However,
it
should be understood by one skilled in the art that the tubes can be any shape
sufficient to contain the members of the safety bar locking mechanism 100. The
locking beams 104 have enclosed end portions and are preferably welded to the
top member 69 of the safety bar guide 66 on opposing sides of the slot. The
locking beams 104 are aligned in generally the same longitudinal manner as the
top member 69, and are spaced apart by at least the thickness of the safety
bar 68.
The pair of die springs 106 are located at the opposing closed end of a
locking
beam 104, and are oriented in a manner such that the biasing force of the die
springs 106 is directed toward the rack 94 of the safety bar 68. A safety pin
102 is
located inboard of each of the die springs 106, and each safety pin 102 passes
through both opposing locking beams 104 in a normal direction. FIG. 1 I A
CA 02530103 2005-12-14
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illustrates the safety bar locking mechanism 100 in a locked condition sucli
that
the safety pins 102 are engaged with the rack 94 of the safety bar 68, thei-
eby
preventing downward movement of the safety bar 68 and moving mast 54 during
engagement.
[0056] A dual-direction hydraulic piston 108 is disposed within the center
portion of each locking beam 104 and is configured to be actuated in the
longitudinal directions opposite the forces exerted by the die springs 106, as
illustrated in FIGS. 11A and 11B. The die springs 106 act to bias the safety
pins
102 toward the center of the safety bar locking mechanism 100 in order for the
safety pins 102 to create a locking engagement with the rack 94 of the safety
bar
68. However, the pistons 108 also act to disengage the safety pins 102 from
the
rack 94 on the safety bar 68. FIG. l IB illustrates the safety bar locking
mechanism 100 in an unlocked condition such that the piston 108 is actuated to
force the safety pins 102 to disengage the rack 94 of the safety bar 68 and
the
safety bar 68 can be lowered. The safety bar locking mechanism 100 allows all
upward movement of the safety bar 68 through the safety bar guide 66, but
prevents downward movement unless the hydraulic pistons 108 have been
actuated.
[0057] In operation, the pistons 108 are in an actuated position as the tilt
arm
50 is rotated from the horizontal to the vertical position, as shown in FIG.
11B,
because the moving mast 54 is being lowered with respect to the fixed mast 52
as
the tilt arm 50 is being raised to the vertical position. Once the tilt arm 50
is in the
vertical position, the power supply to the pistons 108 is interrupted, and the
die
springs 106 bias the safety pins 102 into engagement with the rack 94 on the
safety bar 68. However, the rack 94 is configured with angled surfaces 95 such
that as the moving mast 54 and safety bar 68 are raised, the angled surfaces
95 of
the rack 94 slidingly force the safety pins 102 outward toward the ends of the
locking beams 104 until the safety pins 102 are again forced by the die
springs 106
into engagement with the next inlet of the rack 94. Once the desired height of
the
lifting mechanisms 45, 46 is achieved, the die springs 106 continue to bias
the
safety pins 102 into engagement with the rack 94 on the safety bar 68 thereby
CA 02530103 2005-12-14
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maintaining the height of the lifting meclianisms 45, 46 and the railcar-
engaging
member 29. The sa}ety pins 102 rest, and ai-e retained, within the hook-shaped
openings in the rack 94. To lower the lifting mechanisms 45, 46, the pistons
108
must first be actuated by the power unit 42, thereby disengaging the safety
pins
102 from the inlets of the rack 94 and allowing the safety bar 68 to be
lowered
without interference from the safety pins 102.
100581 The top portion of the ratcheted safety bar 68 is attached to a loading
member 110 that is located at the top edge 88 of the top plate 86, as
illustrated in
FIG. 8. The loading member 110 is attached to the second distal end 82 of both
opposing side rails 80 of the moving mast 54 such that the loading member 1 10
forms the fifth outer surface of an enclosed lifting mechanism 45, 46 of the
jack
assembly 41. The moving mast 54 of the tilt arm 50 further includes a
triangular
end piece 116 attached to the outward-facing surface of the loading member 110
to prevent damage to the jack assembly 41 while the jack assembly 41 is being
placed in an operative position.
[00591 In addition, a pair of upper cylinder supports 112 are also attached to
the inward-facing surface of the loading member 110, as illustrated in FIGS. 8
and
9A. Each upper cylinder support 112 includes a pair of spaced-apart upper
bearing members 113 and an upper support pivot 114. The pair of spaced-apart
upper bearing members 113 are attached to the loading member 1 10 and the top
plate 86 in a manner similar to the connection of the lower cylinder supports
72.
Each of the upper bearing members 1] 3 includes a hole through which an upper
support pivot 114 is passed in a generally normal orientation. The rod
mounting
portion 1 l 5 of each hydraulic cylinder 74 is disposed between a pair of
upper
bearing members 113, wherein the upper support pivot 114 passes through the
hole in one upper bearing member 113, through the hole in the rod mounting
portion 115 of the hydraulic cylinder 74, and then through the hole in the
second
upper bearing member 113.
100601 The fixed and moving masts 52, 54 of each lifting mechanism 45, 46
are operatively connected by a pair of hydraulic cylinders 74. An example of a
suitable hydraulic cylinder includes the model PMC-5636 manufactured by Prince
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Hydraulics Corp of North Sioux City, South Dakota. The model PMC-5636
hydraulic cylinders have a 4-inch bore, a 2-incli diamete-- rod, a 36-inch
stroke,
and a 46-inch retracted height. "I'he base mounting portion 78 of each
hydraulic
cylinder 74 is attached to a lower cylinder support 72 connected to the fixed
mast
52 and the rod mounting portion 115 of each hydraulic cylinder 74 is attached
to
an upper cylinder support 112 connected to the moving mast 54, as illustrated
in
FIGS. 9A and 10. Additionally, upon the assembly of each lifting mechanism 45,
46, the rollers 62 attached to the moving mast 54 are disposed within the c-
shaped
cross section of the side members 56 of the fixed mast 52 and the rollers 62
of the
fixed mast 52 are disposed within the c-shaped cross section of the side rails
80 of
the moving mast 54. In operation, as the moving mast 54 is raised or lowered
with
respect to the fixed mast 52, the rollers 62 provide a smooth sliding
connection
between the fixed and moving masts 52, 54.
[0061] The second lifting mechanism 46 is configured as a tilt arm 50. The
tilt
arm 50 is adapted to rotate between a first, generally horizontal, and a
second,
generally vertical position when the jack assembly 41 is in an operative
position
beneath a railcar 12, as illustrated in FIGS. 6A-6C. The tilt arm 50 is the
second
lifting mechanism 46, and is fully enclosed in order to prevent damage to the
lifting mechanism 46 either during transportation from one location to another
or
during operation of the jack assembly 41. As the tilt arm 50 is rotated
between the
horizontal and vertical positions, both the fixed and moving masts 52, 54
rotate
together as a unit. However, when the tilt arm 50 is in the vertical position,
the
moving mast 54 can be raised and lowered in the vertical direction with
respect to
the stationary fixed mast 52, as illustrated in FIG. 6D.
[0062] The tilt arm 50 is rotationally connected to the distal end of the
frame
rails 30 of the railcar-engaging section 44 opposite the first lifting
mechanism 45
and power unit 42, as shown in FIGS. 4 and 12A-12C. In the illustrated
embodiment, the tilt arm 50 is connected to the railcar-engaging section 44 at
two
pairs of rotational connections 31, 32. The outer rotational connections 31
are
pivotal about a first axis 33. The inner rotational connections 32 utilize a
trunnion
37 attached to the moving mast 54 and a corresponding trunnion 38 attached to
the
CA 02530103 2005-12-14
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railcar-engaging section 44 wliereby the trunnions 37, 38 are operatively
connected by a knuckle link 36. A second axis 34 is formed at the coupling
between the knuckle links 36 and the moving niast trunnions 37, and a third
axis
35 is formed at the couplings between the knuckle links 36 and the trunnions
38 of
the railcar-engaging section 44.
100631 FIGS. 12A-12D illustrate the inner and outer connections 3 1, 32
between the tilt arm 50 and the railcar-engagiiig section 44 as the tilt arm
50 is
rotated between the horizontal and vertical positions. In FIG. 12A, the
knuckle
links 36 are generally horizontal, and the first and second axes 33, 34 are
vertically
aligned with respect to each other. FIG. 12B illustrates the orientation of
the first,
second, and third axes 33, 34, 35 as the tilt arm 50 is being raised or
lowered.
FIGS. 12C and 12D illustrates the tilt arm 50 in the vertical position,
wherein the
second and third axes 34, 35 are vertically aligned with respect to each
other.
[0064] The pair of hydraulic cylinders 74 of the lifting mechanism 46 in the
tilt
arm 50 operate to rotate the tilt arm 50 between the horizontal and vertical
positions. When the jack assembly 41 is first placed beneath a railcar 12, the
tilt
arm 50 is in the horizontal position and the rods of the hydraulic cylinders
74 in
the tilt arm 50 are extended about 20.3 cm (8 in.). The rods of the hydraulic
cylinders 74 are contracted in order to rotate the tilt arm 50 to the vertical
position.
As the tilt arm 50 reaches the vertical position, the rods are completely
contracted
into the hydraulic cylinders 74. As the moving masts 54 of the lifting
mechanisms
45, 46 are raised, the rods of both hydraulic cylinders 74 are extended,
thereby
lifting the railcar-engaging member 29 together as a unit with the moving
masts
54.
OPERATION OF THE INVENTION
[0065] As previously discussed, the jack assembly 41 is placed between a set
of railroad track rails 20 and the frame 18 of a railcar 12. Preferably, the
railcar-
engaging section 44 is placed beneath the railcar 12 such that the power unit
42 is
located on one side of the railcar 12 and the tilt arm 50 is located on the
opposite
side of the railcar 12. The jack assembly 41 is placed in an operative
position such
CA 02530103 2005-12-14
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that the frame rails 30 are in a substantially perpendicular relationship with
respect
to the track rails 20. In one embodiment, the frame rails 30 of the railcar-
engaging
section 44 include markings on the upper surface to assist the user in
aligning the
jack assembly 41 atop the set of track rails 20. In an alternative embodiment,
an
electronic device is attached to the first lifting mechanism in order to
detect the
distance between the first lifting mechanism and the frame of the railcar to
ensure
proper alignment of the jack assembly. Proper alignment of the jack assembly
41
results in more efficient use by preventing one of the opposing lift
mechanisms 45,
46 from bearing a disproportional amount of the weight of the railcar 12.
[0066] Once the jack assembly 41 is aligned beneath the railcar 12, the
housing
48 of the power unit 42 is rotated to the open position, whereby the
operational
controls of the jack assembly 41 can be accessed by the user. The motor is
activated, and power is provided to the electrical control system. The user is
then
free to depress the "up" and "down" buttons on the control pendant to control
the
movement of the jack assembly 41.
100671 To raise the railcar with the jack assembly 41, the user depresses the
"up" button. Once the "up" button is depressed, the electrical control system
activates the hydraulic pump to provide power only to the pair of hydraulic
cylinders 74 located in the tilt arm 50. First, the slightly extended rods of
the
hydraulic cylinders 74 in the tilt arm 50 are contracted, and the pistons 108
in the
safety bar locking mechanism 100 are actuated to allow the moving mast 54 to
be
lowered with respect to the fixed mast 52. As the rods of the hydraulic
cylinders
74 are contracted, the tilt arm 50 rotates from the horizontal position to the
vertical
position. When the tilt arm 50 has rotated to the vertical position, the rods
of the
hydraulic cylinders 74 in the tilt arm 50 are completely contracted. The
railcar-
engaging section 44 includes a magnetic switch (not shown) that is activated
once
the tilt arm 50 has reached the vertical position. The activation of the
magnetic
switch signals the electronic control system to supply power to the hydraulic
cylinders 74 in both lifting mechanisms 45, 46 as the "up" button remains
depressed. Once the magnetic switch is activated, the power supplied to the
pistons 108 in the safety bar locking mechanism 100 is interrupted, and the
die
CA 02530103 2005-12-14
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springs 106 bias the safety pins 102 into sliding engagement with the rack 94
of
the safely bar 68. Thus, as the hydraulic pump provides power to the hydraulic
cylinders 74, the moving inasts 54 of the opposing iiiting inechanisms 45, 46
and
the railcar-engaging tnember 29 are raised to the height determined by the
user.
Once the lifting mechanisms 45, 46 have reached the desired height, the user
releases the button on the control pendant in order to interrupt the power
supplied
to the hydraulic cylinders 74. Once the power to the lifting mechanisms 45, 46
is
interrupted, the safety pins 102 in the safety bar locking mechanism 100
engage
the rack 94 of the safety bar 68 in order to maintain the desired height of
the lifting
mechanisms 45, 46 and railcar-engaging member 29.
(0068] To lower the lifting mechanisms 45, 46 and the railcar-engaging
member 29 from a raised position, the "up" button must be momentarily
depressed
in order to actuate the pistons 108 in the safety bar locking mechanism 100 to
move the safety pins 102 out of engagement with the rack 94 of the safety bar
68.
The "down" button can then be pressed to slowly release the pressure in the
hydraulic cylinders 74, thereby lowering the lifting mechanisms 45, 46 and the
railcar-engaging member 29. Once the hydraulic cylinders 74 have reached the
bottom of their stroke, the magnetic switch between the tilt arm 50 and the
railcar-
engaging section 44 is deactivated. The pair of hydraulic cylinder rods of the
lifting mechanism 76 of the tilt arm are then extended to lower the tilt arm
50 from
the vertical position to the horizontal position. The jack assembly 41 can
then be
removed from beneath the railcar 12 and transported to another location with a
forklift.
(0069] While preferred embodiments of the invention have been described, it
should be understood by one skilled in the art that the invention is not so
limited
and modifications may be made without departing from the invention. The scope
of the invention is defined by the appended claims, and all devices that come
within the meaning of the claims, either literally or by equivalence, are
intended to
be embraced therein.
