Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
HITCI-I ASS~MBLY FOR TRAILER O~ FL~T CAR
BACKGROUND OF TIIE INVENTION
1. Field of the Invention
The present invention relates to a hitch assembly
for semi-trailers mounted on a platform such as a railroad
flat car. More particularly the invention relates to a
hitch assembly adapted for positively securing the forward
end portion of a semi-trailer for travel on a moving flat
car piggyback fashion with the depending kingpin of the
trailer in detachable locking engagement with the hitch
assembly. The hitch assembly is mounted on a carriage
mechanism adapted to elevate a support bed into an operative
position at the proper level above the platform of the
flat car for engagement with a semi-trailer. The carriage
mechanism is collapsible into lowered position adjacent
the surface of the platform when not in use and/or prior
to the final positioning of a semi-trailer on the railway
car for transport.
2. Description of the Prior Art
Over the road motor tractor trailer combinations
have been widely used ~or hauling freight. The trailer
or van component of a tractor trailer combination may be
disconnected from the tractor and is selE supporting for
loading, unloading and/or storage or other stationary usage.
These trailers or vans are commonly provided with a relatively
large downwardly facing bearing plate with a depending
kingpin at the center for connection and disconnection
with a hitch assembly on the truck or tractor of tl~e com-
bination.
Piggyback operations have grown up utilizing
these vans or trailers positioned on railroad cars or flat
~,
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63286-154
cars and secured in position thereon for transport over
railroad right-of-ways to provide a more economical basis of
transpor~ation for goods. A wide variety of hitch mechanisms
and supports therefor mounted on piggyback flat cars have been
provided by companies such as Pul].man Standard, ACF and
Flexivan. United States Patents Nos. 3,035,081; 3,127,142;
3,185,~21; 3,289,987; 3,348,502; 3,358,g45; 3,358,955; and
4,225,276 disclose various piggyback systems for semi-trailers
including hitch assemblies, latch systems and support
mechanisms for securing trailers in place on flat cars for
transport.
Pullman Standard has developed models LP-1, 2, 3, and
4 of a pullup trailer hitch and an inspection and maintenance
manual is provided for these hitches. ~ typical piygyback flat
car with hitches thereon is illustrated on page 240 of the Car
and Locomotive Encyclopedia.
One of the problems associated with many trailers on
flat car hitches is the fact that extremely high loads are
present on the latch mechanism which must be capable of
restraining movement of a kingpin longitudinally of the semi-
trailer. This has resulted in complicated jaw mechanisms such
as screw operated jaws shown in United States Patent No.
4,225,276 or a rotary latch mechanism shown in United States
Patent No. 3,353,955.
SUMMARY OF THE INVENTION
The invention provides a fifth wheel plate structure
for an elevatable hitch assembly for anchoring a semi-trailer
van kingpin to a railroad car for rail transit of the van on
the car, said fifth wheel plate structure comprisin~r for
improving the restraint exercised on the van kingpin against
loadings acting forwardly and rearwardly of the car durincJ rail
~ 63286-154
transit, a bed plate including an upwardly facing bearing
surfacing having a xelative large planar area for load
supportive engagement with the van when the van res~s on the
hitch assembly fifth wheel plate structure and that defines a
kingpin receiving opening and fronk, rear and side betl. plate
port~ons forming the perimeter of said fifth wheel plate
structure, with said fifth wheel plate structure front and rear
portions at and adjacen~ the fifth wheel structure kingpin
receiving opening including integral, thrust resisting, bed
structures that are fixed relative to said bed plate, said
front and rear fifth wheel plate structure portions defining
front and rear stop surfaces at the fifth wheel structure
kingpin receiving opening that are in opposed relation
forwardly and rearwardly of the hitch assembly bed plate, and
that are configured to together define a kingpin receiving
pocket that receives the van kingpin in close fitting relation
thereto when the kingpin is received therein, and that are
backed up by said fixed bed structures, respectively, said bed
plate further defining a kingpin entry slot extending to and
~0 between the said bed plate kingpin receiving pocket from and
through one of the bed plate side portions, said bed plate
kingpin entry slot having its mouth open at the side of the
fifth wheel structure that said bed plate one side portion is
on and extending substantially laterally of the forward and
rearward thrusts to be resisted when the van is in rail
transit, said bed plate entry slot being proportioned to pass
the van kingpin along the length thereof between said stop
surfaces at the kingpin receiving pocket and said one side
portion of said bed, and through said bed one sitle portion, and
a latch mechanism for latching the van kingpin to s~id bed
plate, said latch mechanism comprising: latch means
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63286-15
operatively connected to said bed plate below said bearing
surfacing of same and including a latch member defining latch
surfacing proportioned to, in the closed position thereof,
latchingly engaye the kinypin across said plate entry slot when
the kingpin is disposed within said pocket, said latch member
being articulated to said bed plate for shiftiny forwardly and
rearwardly of said bed plate relative to said pocket when
thrust loadings acting forwardly and rearward of the car are
experienced during the rail transit, whereby said stop surfaces
are respectively backed up by said bed plate structures and
resist said forwardly and rearwardly acting thrust loadings to
the substantial exclusion of said latch member.
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BRIEF DESCRIPTION OF TIIE DRAWINGS
For better understanding of the present inven-tion
reference should be had to the following detailed description
taken in conjunctlon with the drawings in which:
FIG. 1 is a side elevational view of a plurality
of railroad flat cars with semi-trailers mounted thereon
and supported in latch condition by means of hitch assemblies
in accordance with the present invention;
FIG. 2 is a top plan view of a railroad flat
car on which is mounted a plurality of hitch assemblies
constructed in accordance with the features of the present
invention;
FIG. 3 is an enlarged side elevational view of
a hitch assembly in accordance with the present invention
shown in an elevated position for latching engagement with
the kingpin of a semi-trailer mo~lnted on the flat car;
FIG. 4 is a longitudinal cross sec-tional view
of one of the support beds of the hitch assembly as arranged
in accordance with the presen-t invention, taken substantially
along axis "A-A" of Figure 5 and viewing the bed in the
direction of its kingpin entry slot;
FIG. 5 is a bottom plan view of the support bed
shown in FIG. 4, looking in the direction of the arrows
5-5 of FIG. 4, and showing the underside of the support
bed, but with parts broken away and parts shown in section;
FIG. 6 is a front elevational view of the support
bed in accordance with the present invention, with the
ri~ht hand side of the support bed being broken away and
the view being oriented to show the bed disposed in upright
relation;
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FIG. 7 is a fragmentary lateral cross sec-tional
view of the support bed of the hitch assembly taken substan-
tially along line 7-7 of FIG. 5, with the lateral entry
slot side of the support bed being oriented to show the
support bed disposed in uprigh-t rela-tion, and,
FIG. 8 is a fragmentary longitudinal cross sectional
view of the hitch assembly taken substantially along line
8-8 of FIG. 5, looking in the direction of the arrows,
and with the view being oriented to show the support bed
horizontally disposed in upright relation.
BRIEF DESCRIPTION OF A PREFERRED EMBODIMENT
~ eferring now more particularly to the drawings,
a new and improved hitch assembly constructed in accordance
with the features of the present invention is illustrated
in detail in FIGS. 4-8 and referred to generally by the
reference numeral 10. The hitch assembly 10 is especially
designed and adapted for securing a forward end portion
of a semi-trailer van 12 while positioned on a railroad
flat car 14 in piggyback fashion.
, As illustrated best in FIG. 2, customarily railroad
flat cars have a long rectangular base or load platform
16 and guide tracks 18 are provided thereon so as to generally
align a semi-trailer van with a longitudinal axis "A-A"
(see FIG. 5) parallel with a longitudinal, central axis
of the flat car. Customarily the semi-trailer vans 12
are unhitched from their motor tractors (not shown) and
are elevated and loaded on to the platform 16 of the railroad
flat cars 14 with a traveling crane 20 (FIG. 1) adapted
to move the semi-trailer van longitudinally as well as
laterally with respect to the flat car platform so that
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wheels 22 of the semi-trailer van are aligned on opposite
sides of the guide tracks 18.
The hitch assemblies 10 on each flat car are
movable between a lowered or retracted position (as shown
in FIGS. 1 and 2) and an elevated or van supporting position
las shown in FIGS. 1 and 3) for engaging a depending kingpin
24 extending downwardly from a bed plate 26 provided on
the underside of the body of the semi-trailer van. A retractable
support mechanism 28 is provided for supporting each hitch
assembly 10 and each mechanism includes a pair of upstanding
legs 30. The support mechanisms 28 may be of the type
shown and described in Bock U.S. Patent No. 3,127,142,
which patent is incorporate herein by this reference.
In accordance witn the present invention the
hitch assembly 10 includes a support bed structure 32 of
generally rectangular shape as shown best in FIG. 5 having
a flat or planar upper surface 34 for supporting engagement
with the bearing or bed plate 26 on the underside of the
semi-trailer van. The bed structure 32 includes integrally
formed stiffening ribs 36 depending downwardly from the
underside of the plate and extending longitudinally and
parallel of the center axis "A-A", which axis thus defines
the longitudinal center line of the hitch assembly bed
structure 32.
In addition to the longitudinal stiffening ribs
there are provided on the underside of the bed s-truc-ture
32 a plurality of depending laterally extending s-tiffening
ribs 38. The support bed structure 32 is pivotally secured
to upper end portions of the support legs 30 of the re-tract-
ing support mechanism 2~ by means of pivot pins 40 journaled
in bearing sleeves 42 provided in apertures formed in the
ribs 36.
A pair of resilient shock absorbers 44 is provided
for engagement with upper forward edges of the support
legs 30 and these shock absorbers are positioned be-tween
parallel adjacent longitudinal ribs 3~ and are supported
on elongated, headed bolts 46 which project through shor-t,
lateral, stiffening ribs 38a directly facing forward edge
faces 30a of the upright support posts 30 of the mechanism
28 when the posts are in a vertical position (FIG. 4).
Each shock absorber 44 includes a vertical plate 48 of
rectangular shape (FIGS. 4 and 7) which extends upwardly
o~ the bolt 46 for contact with a rounded upper edge face
portion 30b (FIG. 4) on the adjacent support leg 30.
In accordance with the present invention, -the
support bed structure 32 is formed with an elongated lateral
kingpin entry slot 50 having a central axis "s-s" generally
transverse to the bed longitudinal axis "A-A" and intersecting
therewith at a central point "C (FIG.. 5) generally positioned
in the central portion of the upper bed bearing surface
34 as best shown in FIG. 5. The lateral slot 50 is formed
with an outer portion having opposite surfaces 50a diverging
away from one another outwardly to form a large entry mouth
opening at a longitudinal side edge of the bed plate structure
32 in order to receive the kingpin 24 of a semi-trailer
van. The lateral slot 50 defined by -the bed 32 includes
parallel opposite side edges 50b intermediate i-ts length
joining the outwardly diverging surfaces 50a at the slot
outer end with a slot curvilinear, inner end portion SOc
that is in coaxial alignment with the intersection point
g
"C" of the longitudinal axis "~-~ and the lateral or transverse
a~is "B-B as best shown in FIG. 5.
The intermediate parallel slot surfaces 50b defined
by bed 32 are spaced apart by a distance slightly greater
than the outer diameter of an upper segment 24a of the
Xingpin 24 to permit free exit and entry of the pin 24
along the intermediate portion of the bed lateral slot
50. The curvilinear inner portion 50c of the lateral slot
50 is of open circular configura-tion (see FIG. 5) having
a diameter slightly greater than that of the kingpin segment
24a to permit limited movement of the kingpin 24 when seated
therein. The kingpin 24 conventionally includes a portion
24b having a diameter less than that oE the upper portion
24a and an enlarged portion 24c having a diameter substan-
tially the same as the kingpin upper segment 24a as shown
in FIG. 4.
The divergent outer end surfaces 50a of the lateral
slot 50 in the bed plate structure 32 provide a large open
mouth defined by the bed surfaces 50a that guide the kingpin
24 toward the bed entry slot narrow parallel intermediate
surfaces 50b leading into the bed central curvilinear portion
50c. Opposite forward and rear surfaces of -the bed curvilinear
central portion 50c of the slot 50 provide positive fixed
stop surfaces for engaging the pin 24 of a semi--trailer,
which stop surfaces are defined by and are part of bed
32. Because these surfaces are relatively large and are
a fixed part of bed 32, rather than being par-t of a movable
element such as a latch or the like, there is no danger
oE a kingpin 24 once engaged from becoming disengaged from
the bed plate structure 32 when large shock loads are en-
countered in a longitudinal direc-tion.
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In prior art hitch assemblies having a longitu-
dinally oriented en-try slot rather than a lateral slot,
as in the present invention, shock loads in a longitudinal
direction had to be absorbed by a latching mechanism re-
sulting in tile possibility of failure when extreme loads
were encountered. In the hitch assembly 10 of the present
invention because the stop surfaces of the central portion
50c of the slot 50 are a fixed part of the bed 32 and are
backed up by extensive thickness of metal of the bed plate
structure 32, there is little or no danger of the kingpin
24 becoming disengaged from the hitch assembly when extreme
longitudinal shock loads are encountered.
In accordance with the present invention, the
hitch assembly 10 is provided with a hooked shape latch
element 52 for preventing a kingpin 24 from inadvertently
becoming disengaged from the central portion 50c of the
latèral slot 50. The latch element 52 is secured to the
bed plate structure 32 below its upper surfaces 34 as well as
thebed portions defining the entry slot inner end 50c on
a depending pivot pin 54 for movement about a pivot axis
aligned with the bed lateral or transverse axis "B-B",
and that is normal of the plane of the bed surface 34 (See
FIG. 5) between a kingpin engaging latch position (see
the solid line position of Figure 5), and an open position
(see the broken line position of FIG. 5). When latch element
52 is in its open position, the lateral slot 50 ~s clear
for relative movement oE a kingpin 24 into or out of a
seated position in the central segment 50c of the lateral
slot.
The latch element 52 is biased toward a closed
position by a coil spring 56 having loops at opposite ends
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secured around a fixed pin 58a and a pin 58b mounted on
the latch element 52 as shown in FIG. 5. The latch element
52 includes a flange 52a (see ~IGS. 5 and 7) intermediate
its length having a semi-circular surface of slightly larger
diameter than the intermediate segment 24b of the kingpin
~4 to provide tight holding engagement oE the pin 24 within
the slot bed segment 50c. A blind end surface of -the segment
50c of the lateral slot 50 provides the positive fixed
stop for lateral pin forces acting along the axis "B-B"
in one direction and a portion of the latch element flange
52a engaging the pin 24 provides a stop surface in an opposite
lateral direction.
The pivot pin 54 of the latch element 52 is s-trong
and able to well withstand any contemplated lateral forces
transmitted thereto because of an engaged kingpin 24 tending
to move outwardly towards the open end of the lateral slot.
These forces are transmitted through the body of the hook
shaped latch element 52 which is relatively thick and strong.
The lower end flange 24c of the kingpin 24 is disposed
below the underside of the latch elemen-t 52 and is larger
in diameter than the latch element flange 52a so that the
kingpin 24 cannot move upwardly and out of the engaged
position once the latch is closed.
The hook shaped latch element 52 includes a first
outer camming surface 52b facing outwardly towards the
open end of the lateral slot 50 when the latch element
is in the closed position as shown in FIG. 5. In addition,
the latch element includes a second cam surface 52c on
a forward edge face thereof divergent from the cam surface
52b. If the latch element 52 is in a closed position and
there is no kingpin engaged within the slot 50, the la-tch
element 52 will automatically open against the bias of
the spring 56 as kingpin 24 engages the cam surface 52b
on inward movement into the slot 50 along the axis "B-B".
As this occurs, the latch element 52 is biased in clockwise
direction (in the showing of FIG. 5) toward an open position
until the kingpin 24 moves inwardly of the outer edge of
the slot surface 52a of the latch member 52. As this occurs,
the spring 56 is then effective to move the latch element
52 into the closed position of FIG. 5 retaining the kingpin
24 in engaged position against longitudinal or lateral
displacement out of the circular segment 50c of the lateral
slot 50 in the bed plate structure 32.
In accordance with the present invention, the
cam surface 52c of the latch element 52 is adapted to engage
a ~inger 60a provided adjacent the inner edge of an indicator
rod 60 mounted for reciprocal longitudinal sliding movement
(FIG~ 5) as indicated by the arrow D. The rod 60 is secured
for longitudinal sliding movement within spaced apertures
38b formed in coaxial alignment in adjacent transverse
or lateral ribs 38 as shown in FIG. 5. The indicator rod
60 is biased inwardly of the bed structure 32 by a coil
spring 62 that is in coaxial relation around the rod 60
and has an inner end portion contained within a coaxial
tubular element joined with the finger 6Oa at the inner
end as shown in FIG. 5.
As the latch element 52 is pivoted toward an
open position as shown in broken lines in FIG. 5, the cam
surface 52c thereof engages the indicator rod finger 60a
and moves the rod 60 outwardly longitudinally in the direction
of the arrow D. The outer end of the rod 60 is provided
with an indicator element 66, and when this element is
displaced outwardly of a forward edge of the bed plate
structure 32, it provides an indication to a workman tha-t
the latch element 52 is in an open position. When the
indicator 66 element is in a position flush with the forward
edge of the bed plate structure 32 as shown in FIG. 5,
it provides an indication that the latch element 52 is
closed.
It will thus be seen that the latch element 52
is biased toward the closed position but can be moved to
an open condition in order to receive a kingpin by action
of the kingpin upon inward movemen-t into the slot 50 to
engage the cam surface 52b and pivot the latch element
to the open position until the kingpin is seated in the
central segment 50c of the slot. When once seated in this
position, the latch element 52 is then closed by the force
of the bias spring 56 and the indicator 66 again indicates
that the latch element is closed.
In accordance with the present invention, the
latch elemen-t 52 is interconnected through a slotted link
68 to a manual actuating lever 70 having a free outer end
projecting forwardly of a forward rail or face p]ate 72
e~tending transversely across the bed plate structure at
the forward edge. The face plate 72 is secured to lateral
ribs 38 by cap screws 7~ and includes a horizontal upper
edge 72a spaced below a slotted segment 38c in -the forward
lateral rib 38 of the bed plate structure 32 to provide
an elongated slot or opening for the outwardly extending
por-tion of the manual actuating lever 70.
1 ~
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The actuating lever 70 includes a goose neck
shaped inner end portion 70a pivotally secured at i~s inner
end on a pivot pin 76 depending downwardly of the bed plate
structure 32. As shown,in FIG. 5, the manual actuating
lever 70 is pivotable from a latch closed position (shown
in solid lines) in a clockwise direction to a latch open
position (shown in broken lines), and as shown, the outer
end portion of the lever 70 also provides an indication
of the position of the latch element 52.
An inner end of the slo-tted link 68 is pivotally
connected to an ear 52d of the latch element 52 by a pin
78. An outer end portion of the link 68 is formed with
an elongated lost motion slot 68a accommodating a connector
pin 79 extending through the slot and supported on the
manually actuated arm 70 intermediate its ends.
As illustrated in FIG. 5 with the manual actuating
lever 70 in the latch closing position as shown in solid
lines the latch element 52 is normally in the closed position
and the connection between the pin 79 and slot 68a of the
slotted linkage lever 60 permits movement of the latch
element 52 from the closed to the open position without
any corresponding movement of the manual actuating lever
70 being required. The lost motion connection between
the latch element 52 and actuating lever 70 readily permits
movement of the latch element 52 between open and closed
positions as described without requiring corresponding
movement of the actuating lever 70 which may remain in
a latched closing position as shown. It will also be noted
that when the hitch assembly 10 is subjected to shock loads
acting longitudinally of the car (on which a semi-trailer
, 14
van 12 is mounted for rail transit using hitch assembly
10 in the manner disclosed herein), latch element 52 is
free to articulate abou-t its pivot pin 54, as will be apparent
from the Applicant's drawings (see, for instance, FIGS.
5 and 7), so that such shock loads are applied to the indicated
fi~ed stop surfaces of the bed central portion 50c (in
fore and aft directions, as the case may be) along axis
When it is desired to manually open the latch
element 52, the outer end portion of the actuating arm
70 is manually grasped and moved in a clockwise direction
about pivot pin 76 to an ultimate la-tch open position as
shown in broken lines in FIG. 5. ~s this occurs, the pin
79 engages the outer end of the slot 68a and causes the
latch element 52 to pivot in a clockwise direction into
the latch open position as shown in broken lines, where
it is retained against the biasing force of the spring
56 by the manual actuating lever 70. In order to retain
and latch the actuating lever 70 in either an open or closed
position as shown, a pair of lever latch assemblies or
mechanisms 80 are mounted at spaced locations on the forward
rail 72. Each latch mechanism 80 includes a latch member
82 mounted for pivotal movement on a pivot pin 84 provided
on the rail or face plate 72. Each latch member 82 is
biased toward a latching position by a coil spring 86 having
a loop at the upper end connected to a lug 82a of latch
member spaced radially outward of the pivot pin 84 thereof.
loop at the lower end of each bias spring 86 is secured
to a pin 88 FIG. 6 mounted on the forward rail 72 so that
as viewed in FIG. 6 the respective latch members 82 are
biased in opposite directions about the respective mounting
pins 84 toward a latching position for securing the manual
actuating arm 70 in either a latch open or latch closed
position outboard of an upstanding lug 82b of the respective
latch members 82.
As illustrated in FIG. 6, the upstanding lugs
82b of the respective latch members 82 extend upwardly
above the upper edge 72a of the forward rail 72 for engagement
with a~side edge of the manual actuating lever 70. For
this purpose the lugs 82b of each latch member include
an upstanding arm engaging edge surface 83 and a downwardly
and inwardly sloping cam surface 85 adapted for interaction
with an edge of the manual actuating lever 70 as it is
moved toward a latching position at an outer end of the
slot 38c.
Referring now specifically to FIGS. 5 and 6,
when the manual actuating arm or lever 70 is in a latch
member closed position as illustrated, the arm or lever
70 is retained in the latch closed position by engagement
of an edge of the arm or lever 70 with an upstanding latch
surface 83 on the latching lug 82b of the right hand latch
element 82 as shown in FIG. 5. This right hand latch element
or member 82 is biased in a clockwise direction as viewed
in FIG. 6 by its latch spring 86, and in order to release
the indicated latch member 82, a lug 82c at the lower end
is manually pressed downwardly to permit pivoting movement
of the latch in member 82 in question in the direction
of the arrow "F".
After depression of the latching lug 82c so that
the upper end of the lug 82b (of the latch member 82 in
question) moves below the level 72a of the rail, the manual
actuating lever 70 can be moved Erom rig~lt -to left as viewed
in FIG. 6 (clockwise direction as viewed in FIG. 5) toward
an opposite latching assembly 80 on the left hand side
of the forward rail 72 as viewed in FIG. 6. ~s this occurs,
manual lever 70 engages the sloping surface 85 on the lug
82b of the left hand latch element or member 82 causing
the indicated element or member 82 to pivot in a clockwise
direction as indicated by the arrow "E". This movement
continues until the lever 70 moves past the surface 83
of the indicated latch element or member 82 at which time
the latch element or member 82 in question is then biased
by its spring 86 to pivot in a clockwise direction (FIG.
6) to move upwardly so that the edge surface 83 will engage
and hold the edge of the manual arm 70 in the latch element
opening position as shown in dotted lines in FIG. 5.
With the arm or levers 70 in the latch open position
as described, -the latch element 52 is retained in the open
position as shown in broken lines (FIG. 5)so that a kingpin
24 may be moved into or out of the lateral slot 50 as previous-
ly described. The latch activating arm 70 may then be
moved from the latch open position back to the latch closed
position by depressing the release stop lug 82c on -the
left hand latch element 82 (FIG. 6) to pivot the indlcated
latch element or member 82 in a clockwise direction as
shown by the arrow "E" and -then the manual actua-ting lever
70 may be moved from left to right until it is back into
the latch closed position.
Although the present invention has been described
with reference to an i]lustrated embodiment thereof, it
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should be understood that numerous o-ther modifications
and embodiments can be made by those skil.led in the art
that will fall within the spirit and scope of the principles
of this invention.
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