Note: Descriptions are shown in the official language in which they were submitted.
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FIFTH-WHEEL TRAILER CONNECTOR
SPECIFICATION
BACKGROUND OF THE INVENTION
This invention relates to a connector for use with a vehicle
having a fifth-wheel, or gooseneck, hitch.
When a vehicle tows a fifth-wheel or gooseneck trailer, and
the vehicle drops into a hole or rut in the road, the vehicle
experiences a hard bounce. This is because the trailer tongue is
exerting a downward force on the trailer hitch equal to the
tongue weight. The towing vehicle reacts as if a load, equal to
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the tongue weight, is in the bed of the vehicle whenever the
towing vehicle hits a rut or hole.
In the past their have been several trailer hitches
described that have sought to overcome the hard ride problem,
although these descriptions addressed different hitches with
different couplings than the present invention. In U.S. Patent
4,304,419, an earthmoving tractor-trailer combination uses an
additional link to strengthen the coupling to prevent the forward
edge of the trailer from bouncing toward the ground whenever the
tractor hits a hole or rut. U.S. Patents 3,194,584 and 3,441,291
address the problem of towing a towed vehicle using a ball hitch
attached at the rear of the towing vehicle. These inventions are
representative of devices which use torsion bars to overcome the
tendency for the trailer hitch to drop whenever the towing
vehicle drops into a rut or hole.
None of the above patents describe a structure that can be
used with a fifth-wheel, or gooseneck, trailer connector which
can be mated with a fifth-wheel hitch, or gooseneck ball, mounted
in the bed of a truck. What is needed is a device which can be
used with a fifth-wheel or gooseneck connector which can be used
to dampen shocks as a towing truck drops into a hole or rut.
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SUMMARY OF INV~;N'1'ION
The present invention relates to apparatus which softens the
ride of a towing truck when pulling a trailer having a fifth-
wheel, or gooseneck, trailer hitch connector.
A trailer having a fifth-wheel, or gooseneck, connector has
a pair of members extending from the trailer and converging at
the other end. These members are attached to a cylindrical
housing, having a longitudinal axis, where the members converge.
The longitudinal axis is oriented substantially perpendicularly
to the bed of the trailer.
An elongate, cylindrical kingpin is coaxially mounted and
connected to the housing. At a lower end the kingpin has a space
below the housing before a lip extends from the kingpin. Below
the lip, the kingpin terminates in either a fifth-wheel
connector, or a gooseneck connector as appropriate for mating
with a fifth-wheel, or gooseneck, hitch.
A stub, having a fixed end and a pivotal connection at the
other end, has its fixed end connected to the kingpin in the
space above the lip. An arm has one end pivotally connected to
the pivotal connection end of the stub. The other end of the
arm, the free end, is free to pivot about the stub in a
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rotational plane. If a force is applied to the arm orthogonal to
the rotational plane, however, the arm can exert pressure to
rotate the kingpin.
A resilient means is attached between the free end of the
arm and the rear of the towing truck to bias the free end toward
the truck, in a plane substantially orthogonal to the rotational
plane. As the rear wheels of the truck drop into a hole, the
kingpin, attached to the trailer, remains oriented substantially
the same as before the rear wheels dropped. But the distance
between the free end and the rear of the truck is increased with
the dropping of the truck's rear wheels.
In this situation, the resilient means places an additional
bias on the rear of the truck tending to lift the rear of the
truck. Then as the truck rolls out of the hole further along the
road, the movements are reversed. The free end remains
substantially oriented as it was before the drop of the rear
wheels, but the rear of the truck rises out of the hole. This
reduces the bias that was recently increased. The resilient
means thus acts as a shock absorber.
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BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be clearly understood and
readily carried into effect, a preferred embodiment of the
invention will now be described, by way of example only, with
reference to the accompanying drawings wherein:
Fig. 1 is an elevational view of a connector for a fifth-
wheel trailer according to the present invention;
Fig. 2 is a plan view of the connector shown in Fig. l;
Fig. 3 is an enlarged, elevational view of a spring
mechanism shown in Fig. l;
Fig. 4 is a left side view of the spring mechanism shown in
Fig. 3;
Fig. 5 is an enlarged, cross-sectional view taken along the
line 5-5 in Fig. l;
Fig. 6 is an enlarged, elevational view of a kingpin and
stub shown in Fig. l;
Fig. 7 is a plan view of the kingpin and stub shown in Fig.
6;
Fig. 8 is an elevational view of a fifth-wheel extension
shown in Fig. l;
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Fig. 9 is an elevational view of a gooseneck extension shown
in Fig. l;
Fig. 10 is a bottom view of the gooseneck extension shown in
Fig. 9; and
Fig. 11 is a cross-sectional view of the gooseneck extension
taken along the line 11-11 in Fig. 9.
~ESCRIPTION OF A PREFERRED EMBODI~T
A preferred embodiment of the fifth wheel trailer connector
10 is shown in Fig. 1 for use with a conventional, fifth-wheel or
gooseneck, trailer-hitch assembly. A conventional trailer tongue
has a pair of members 12 rigidly attached to the bed of a trailer
14 at one end. Members 12 converge at the other end, as best
seen in Fig. 2, to attach to and hold an elongate, cylindrical
housing 16 having a longitudinal axis. ~he longitudinal axis of
housing 16 is aligned substantially perpendicular to the trailer
bed. In addition as best seen in Fig. 1, housing 16 has holes 34
bored therethrough which are aligned substantially perpendicular
to the longitudinal axis.
An elongate, cylindrical kingpin 18, coaxially mounted
within housing 16, has a grooved, solid extension 20 at the lower
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end for mating with a conventional fifth-wheel, or gooseneck,
trailer hitch 22, located in the bed of a truck 24. Jaws in a
conventional fifth-wheel trailer hitch 22 fit within groove 23,
best seen in Fig. 8, to prevent solid extension 20 from raising
out of the trailer hitch.
As an alternative to the fifth-wheel hitch shown in Fig. 1,
gooseneck trailer connectors 10 have an end of extension 20
hollowed-out for receiving a ball-type connector as best seen in
Figs. 9-11. These trailer connectors 10 ride on a conventional
trailer hitch ball mounted in the bed of truck 24. In this
latter instance, extension 20 is pinned to the hitch ball by
using a bolt 25 that passes through the sides of extension 20 and
under the ball to prevent the extension from raising off the
conventional ball hitch.
As best seen in Fig. 6 above both types of extension 20, a
lip 30 extends away from kingpin 18. Adjacent the upper portion
of kingpin 18, a series of holes 21 are bored through the kingpin
substantially perpendicular with the longitudinal axis. As best
seen in Fig. 1, kingpin 18 can then be slipped into housing 16
with extension 20 and lip 30 extending below the housing. With
trailer 14 and truck 24 nearly level, kingpin 18 can then be slid
up or down within housing 16 so as to align a pair of holes 21
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with holes 34. When holes 34 and a pair of holes 21 line up, the
kingpin can then be secured to the housing by passing pins (not
shown) through aligned holes 34 and holes 21 in the kingpin.
A lever 36 has two components: a stub 38, which is fixedly
attached to kingpin 18, and an arm 40 which can freely pivot
about stub 38 in one plane but which can provide leverage to
rotate the stub in an orthogonal plane.
Stub 38 is connected to kingpin 18 to form a fixed end for
lever 36. At one end stub 38 has a rectangular, plate 42
attached substantially perpendicular to the sides of stub 38. On
a side of plate 42 opposite stub 38, a saddle 44, curved to fit
kingpin 18, is attached to the plate as by welding. Four bolt
holes are drilled through rectangular, plate 42--one hole
adjacent to each of the four corners. As best seen in Fig. 6,
stub 38 can then be fixedly mounted to kingpin 18 by placing
plate 42 and saddle 44 adjacent the rear of kingpin 18 and just
above lip 30. U-bolts 48 are then placed around kingpin 18 and
through corresponding bolt holes in plate 42. Nuts 50, placed on
each U-bolt 48, are tightened to securely hold stub 38 to kingpin
18 and to securely fix this end of lever 36. Lip 30 prevents
this end of lever 36 from riding down on kingpin 18 as the
present invention is being used. Adjacent the other end of stub
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38 as best seen in Fig. 5, a pipe 46, having a central bore 47
aligned substantially perpendicular with the longitudinal axis of
kingpin 18, is welded to the stub.
The other portion of lever 36 is arm 40 which provides
leverage in a direction orthogonal to a rotational plane. Arm 40
is pivotally connected to stub 38 at one end and shaped to extend
over the rear of truck 24 toward the other, free end. The free
end is permitted easy swinging movement within the rotational
plane around the pivotal connection. At the pivotally connected
end of arm 40, plates 54 are attached on opposite sides of the
arm and are sized to extend on opposite sides of stub 38 as best
seen in Fig. 1. Coupling holes are drilled in plates 54 to mate
with the corresponding central bore 47 of pipe 46. The
centerlines of the coupling holes and central bore 47 are
substantially aligned with each other and with the longitudinal
axis of kingpin 18. A coupling pin 56 is then inserted through
the coupling holes and corresponding central bore 47 to permit
arm 40 to pivot about coupling pin 56 as best seen in Fig. 5. As
shown in Fig. 1, a cotter key 58 is placed through coupling pin
56 to hold the pin in its inserted position. Arm 40 can thus
transfer forces acting away from or toward the ground to stub 38,
but at the same time the arm is free to swing about coupling pin
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56. The free end of arm 40 thus forms the free end of lever 36.
The free end of lever 36 in this configuration can be used to
rotate the longitudinal axis of kingpin 18.
At the free end of lever 36, a spring mechanism 60 is
attached. Spring mechanism 60 is used to bias the rear of truck
24 upward. As best seen in Figs. 3 and 4, spring mechanism 60,
at one end, is attached to arm 40 and, at the other end, is
attached to a hitch bar 62. As best seen in Fig. 1, hitch bar 62
is attached to the rear of truck 24.
As best seen in Figs. 3 and 4, spring mechanism 60 uses a
coiled spring 64. A bent hangar 66 is turned at opposite ends to
engage the bottom coils of spring 64 and hold them. Intermediate
the ends, bent hangar 66 is looped over pin 68 to prevent the
hangar from pulling away from arm 40.
Also an inverted, bent hangar 70 is led through coiled
spring 64 in a direction opposite to hangar 66. This permits the
turned ends of inverted hangar 70 to grab the top coils of spring
64 and hold them while the looped portion on the inverted hangar
extends downward below the coils of the spring as best ~een in
Figs. 3 and 4. With this arrangement, as the looped portion of
inverted hangar 70 is pulled away from arm 40, the bias of spring
64 increases.
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A conventional hand winch 72 is used to place a bias on
spring 64. Conventional winch 72 has a pulley 74 with an
incorporated hook 84 mounted intermediate the ends of cable 76.
At the end of cable 76 capable of being pulled from conventional
winch 72, a shackle 78, connected to the cable, can be connected
to a ring on conventional hitch bar 62 as shown in Fig. 3 and 4
to hold one end of the cable to the hitch bar. Conventional hand
winch 72 is attached to hitch bar 62 in such a way that crank 80
and associated pawl lever 82 are easily accessible to tighten
cable 76 when putting a strain on spring 64.
Hook 84, incorporated as part of conventional pulley 74, is
placed over the loop of inverted hangar 70 so that as a strain is
placed on pulley 74, associated hook 84 can place a bias on
spring 64.
In operation, fifth wheel trailer 14 and truck 24 are placed
on level ground and kingpin 18 adjusted vertically to align holes
34 and 21. With these holes aligned, kingpin 18 can then be
pinned to housing 16. Fifth wheel trailer 14 is then connected
to truck 24 by mating extension 20 of kingpin 18 with a
conventional fifth-wheel trailer hitch 22, or, if using a
gooseneck trailer, by placing ball extension 20 on top of a
conventional ball hitch mounted in the bed of truck 24 and then
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pinning the ball with bolt 25. The free end of arm 40 i5
connected to the rear of truck 24 by hooking hook 84 into the
loop of inverted hangar 70 and tightening cable 76 by using winch
72.
As truck 24 is driven away, trailer 14 trails behind the
vehicle with kingpin 18 pulling in trailer hitch 22 in the
conventional manner. Conventional fifth-wheel trailer hitch 22,
having a mounting base and a grabbing plate, is mounted so that
any tilting between the mounting base and grabbing plate occurs
around an axis that is substantially parallel with an axle of
truck 24. If the rear wheels of truck 24 fall into a hole, the
mounting base of trailer hitch 22, fixedly mounted in the bed of
the truck, rotates backwardly as the vehicle's rear wheels
descend. Kingpin 18, however, remains oriented in housing 16
with substantially the same orientation as before the vehicle's
rear wheels started to descended. The distance between the rear
of the truck and the free end of lever 36 increases as the rear
wheels of the truck drop.
With a gooseneck trailer hitch, kingpin 18 is pulled by a
trailer hitch ball mounted in the bed of truck 24. Similarly as
the rear wheels of truck 24 drop into a hole, there is rotational
movement by kingpin 18 around a ball fixedly mounted in the bed
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of truck 24. The distance between the rear of the truck and the
free end of lever 36 again increases in this situation as the
rear wheels of the truck drop.
The increasing separation between the free end of lever 36
and the rear of the truck using either hitch is resisted however.
The increasing separation between the free end of lever 36 and
the rear of the truck places additional bias on spring 64. Since
spring 64 is connected between the rear of truck 24 and arm 40,
increasing separation increases the resilient force acting on the
rear of truck 24. This tends to raise the rear of the truck 24.
Thus spring 64 tries to keep the rear of truck 24 from falling
rapidly whenever the rear wheels enter a hole or rut. Because
spring 64 acts to counteract the falling of the rear of truck 24
as the rear wheels of the truck drop into a hole, the spring acts
as a shock absorber.
As the rear wheels of truck 24 come out of the hole further
along a road, kingpin 18 pivots backward in grab plate of trailer
hitch 22, or around a gooseneck trailer hitch ball, to become
more nearly vertically oriented to the truck bed. In this
situation, the free end of arm 40 pivots closer to truck 24.
With a decreased separation between the free end of arm 40 and
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the rear of truck 24 now occurring, the resilient force recently
increased is now relaxed.
If truck 24 turns with a trailer 14 connected, stub 38 will
remain directly beneath members 16, while arm 40 will pivot
around coupling pin 56 so that its free end will remain nearly
over hitch bar 62. The two ends of lever 36 thus respond
differently: one end follows the motion of the turn, and the
other end barely responds to the motion. Stub 38 is short enough
that spring mechanism 60, connected to the free end of arm 40,
will remain clear of the bed of truck 24 even though coupling pin
56 is being rotated closer to the front of the truck. Since the
top of spring mechanism 60 is moving closer to the front of truck
24, the effect will be to slightly change the bias of spring 64.
While the fundamental novel features of the invention have
been shown and described, it should be understood that various
substitutions, modifications and variations may be made by those
skilled in the art without departing from the spirit or scope of
the invention. Accordingly, all such modifications or
variations are included in the scope of the invention as defined
by the following claims.
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