Note: Descriptions are shown in the official language in which they were submitted.
COMBINED GAGE WHEEL AND INTEGRATED TRANSPORT SYSTEM
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent
Application No.
62/764,936, filed August 15, 2018, which is incorporated herein by reference
in its entirety.
FIELD OF THE DISCLOSURE
[0002] The present specification relates generally to the field of
agricultural equipment
transportation. More particularly, the present specification relates to a
transportation and
steering system for agricultural equipment.
BACKGROUND
[0003] A harvesting machine generally includes a header and a vehicle (e.g., a
tractor) for
carrying the header. One end of the header is attached to the vehicle. The
other end of the
header includes ground wheels for supporting the vehicle in movement across
the ground. When
the header needs to be transported to another location after the harvesting
operation, the header
may be detached from the vehicle and a trailer is usually used for
transporting the header. Other
agricultural equipment may also need to be transported from one field to
another.
SUMMARY
[0004] One implementation of the present disclosure is a steering system for
an agricultural
machine. The steering system includes a first and second wheel assembly. Each
wheel assembly
includes an axle assembly including an axle, wheels rotatably connected to the
axle, and a
double-action hydraulic cylinder. In some embodiments, the double-action
hydraulic cylinder is
configured to pivot the wheels in either direction to indicate a direction of
turn. In some
embodiments, the double-action hydraulic cylinder of the first wheel assembly
is hydraulically
linked in its operation to an operation of the double-action hydraulic
cylinder of the second
wheel assembly.
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[0005] In some embodiments, the wheels of each wheel assembly are spaced a
distance apart
substantially equal to or greater than the width of the agricultural machine.
[0006] In some embodiments, the axle assembly includes a tongue connected to
the double-
action hydraulic cylinder. The tongue is configured to pivot about a pivot
point, and is
configured to steer the wheels through tie rods connected to the tongue and
the wheels, according
to some embodiments.
[0007] In some embodiments, the double-action hydraulic cylinder is attached
on one end to
the tongue, and on the other end to the axle.
[0008] In some embodiments, the tongue is configured to either be pivoted by
an expansion or
retraction of the double-action hydraulic cylinder, or to be pivoted by an
external force and drive
the expansion or retraction of the double-action hydraulic cylinder.
[0009] In some embodiments, the double-action hydraulic cylinder of the first
wheel assembly
is configured to be expanded or retracted by the pivoting of the tongue of the
first wheel
assembly and is hydraulically linked to the double-action hydraulic cylinder
of the second wheel
assembly. In some embodiments, the double-action hydraulic cylinder of the
second wheel
assembly is configured to drive the tongue of the second wheel assembly to
control the turn of
the wheels of the second wheel assembly.
[0010] In some embodiments, the tongue of the first wheel assembly is
configured to
selectively attach to a vehicle for transportation or to selectively attach to
a beam configured to
attach to the vehicle for transportation. In some embodiments, the tongue is
further configured
to be pivoted by a motion of the vehicle.
[0011] In some embodiments, the double-action cylinder of the first wheel
assembly is
configured to hydraulically link to the double-action cylinder of the second
wheel assembly by
transferring hydraulic fluid from the double-action cylinder of the first
wheel assembly to the
double-action cylinder of the second wheel assembly to expand or retract the
double-action
cylinder of the second wheel assembly.
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[0012] In some embodiments, the wheel assemblies include a spring. The spring
is configured
to attach at one end to the tongue and at the other end to a protrusion from
the axle, and apply a
force to an outside wheel of the wheels according to some embodiments. The
force is
transmitted through the tongue and the tie rods to the outside wheel according
to some
embodiments. In some embodiments, the outside wheel is the wheel at an
outermost distance
from a center of a turn.
[0013] In some embodiments, the spring connects at one end to a tongue half In
some
embodiments, the tongue half is pinned to the tongue.
[0014] Another implementation of the present disclosure is a wheel assembly
for an
agricultural machine. The wheel assembly includes a set of wheels, a header, a
double-action
cylinder, and a tongue. The header is configured to rotate between a field
mode and a
transportation mode according to some embodiments. In some embodiments, the
double-action
cylinder is configured to expand or retract. In some embodiments, the
expanding and retracting
of the double-action cylinder steers a set of wheels. In some embodiments, the
tongue is
configured to connect to the double-action cylinder and pivot based on the
expansion or
retraction of the double-action cylinder.
[0015] In some embodiments, the wheel assembly includes an axle. In some
embodiments, the
double-action cylinder connects at one end to the axle, and at the other end
to the tongue.
[0016] In some embodiments, the wheel assembly includes a set of tie rods,
wherein the tie
rods each connect at one end to the tongue and are configured to steer the
wheels based on the
pivoting of the tongue.
100171 In some embodiments, the tongue is configured to either pivot about a
pivot point, drive
the expansion and retraction of the double-action cylinder and drive the tie
rods to steer the
wheels, or to be driven by the expansion and retraction of the double-action
cylinder, pivot about
the pivot point, and drive the tie rods to steer the wheels based on the
expansion and retraction of
the double-action cylinder.
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[0018] In some embodiments, the wheel assembly includes a spring. In some
embodiments,
the spring is configured to attach at one end to the tongue and at the other
end to a protrusion
from the axle. In some embodiments, the spring may apply a force to an outside
wheel of the
wheels. In some embodiments, the force is transmitted through the tongue and
the tie rods to the
outside wheel. In some embodiments, the outside wheel is the wheel at an
outermost distance
from a center of a turn.
[0019] In some embodiments, the spring connects at one end to a tongue half.
In some
embodiments, the tongue half is pinned to the tongue.
[0020] In some embodiments, the double-action cylinder is configured to
hydraulically link to
a second double-action cylinder. In some embodiments, the double-action
cylinder transfers
hydraulic fluid to the second double-action cylinder to expand or retract the
second double-
action cylinder.
[0021] In some embodiments, the wheels are spaced a distance apart greater
than or equal to
the width of the agricultural machine.
[0022] Another implementation of the present disclosure is a method for four-
wheel steering
on an agricultural machine. The method includes receiving a force input to a
tongue. The force
input to the tongue indicates a direction and magnitude of a turn of a vehicle
and the tongue is
configured to pivot in a direction and amount proportional to the direction
and magnitude of the
turn of the vehicle. The method further includes expanding or retracting a
first double-action
cylinder based on the direction and amount of pivot of the tongue, expanding
or retracting a
second double-action cylinder based on the expansion and retraction of the
first double-action
cylinder, steering a first set of wheels based on the direction and amount of
the pivot of the
tongue, and steering a second set of wheels based on the expansion and
retraction of the second
double-action cylinder. In some embodiments, the first double-action cylinder
is connected at an
end of the tongue.
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[0023] In some embodiments, the method includes receiving a force input to the
tongue
through a beam connected to the vehicle.
[0024] In some embodiments, the method includes expanding or retracting the
second double-
action cylinder based on the expansion and retraction of the first double-
action cylinder by
transferring hydraulic fluid out of a first chamber of the first double-action
cylinder into a second
chamber of the second double-action cylinder and transferring hydraulic fluid
out of a second
chamber of the first double-action cylinder into a first chamber of the second
double-action
cylinder.
[0025] In some embodiments, the method includes steering the first set of
wheels based on the
direction and amount of the pivot of the tongue by driving a set of tie rods
with the tongue. In
some embodiments, the set of tie rods are connected to the tongue and the
first set of wheels.
[0026] In some embodiments, the method includes steering the second set of
wheels by
pivoting a second tongue connected to and pivoted by the second double-action
cylinder, and
driving a second set of tie rods connected to the second tongue and the second
set of wheels.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Exemplary embodiments will become more fully understood from the
following
detailed description, taken in conjunction with the accompanying drawings,
wherein like
reference numerals refer to like elements, and:
[0028] FIG. 1 is a perspective view schematic drawing of an agricultural
harvester, including
an agricultural harvesting head assembly, according to some embodiments.
[0029] FIG. 2 is a perspective view schematic drawing of the agricultural
harvesting head
assembly of FIG. 1 including an axle and wheel assembly, depicting a field
mode and a
transportation mode, according to some embodiments.
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[0030] FIG. 3 is a bottom perspective view schematic drawing of the axle
assembly of FIG. 1,
according to some embodiments.
[0031] FIG. 4 is a top perspective view schematic drawing of the axle assembly
of FIG. 1,
according to some embodiments.
DETAILED DESCRIPTION
[0032] The detailed description set forth below is intended as a description
of various
configurations of the subject technology and is not intended to represent the
only configurations
in which the subject technology may be practiced. The appended drawings are
incorporated
herein and constitute a part of the detailed description. The detailed
description includes specific
details for the purpose of providing a thorough understanding of the subject
technology.
However, it will be clear and apparent to those skilled in the art that the
subject technology is not
limited to the specific details set forth herein and may be practiced using
one or more
implementations.
[0033] Referring generally to the FIGURES, the present disclosure provides a
steering and
transportation system for transporting agricultural harvesting equipment. In
some embodiments,
the agricultural harvesting equipment is an agricultural harvesting head
detached from a
combine. In some embodiments, other agricultural equipment may use the
steering and
transportation system for transportation. In some embodiments, the combine and
the agricultural
harvesting head are used to harvest crops, process the crops and transport
them to storage areas.
During harvesting operation, the combine pushes the agricultural harvesting
head which travels
along the ground, supported on one end by the combine, and supported on the
ground by wheels
(also referred to as gage wheels), according to some embodiments. In some
embodiments, the
agricultural harvesting head may sever the crop and transfer it into the
combine for processing
and storage. In some embodiments, the harvesting head includes a pair of
similar wheel
assemblies near both ends of the harvesting head. When the harvesting head
must be transported
(e.g., on roads from one field to another), the wheel assemblies rotate 90
degrees and lock in
position, according to some embodiments. The harvesting head may then be
attached to a
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vehicle for transportation. In some embodiments, each of the wheel assemblies
includes a
double-acting hydraulic cylinder configured to turn the wheels by moving tie
rods each
connected to the hub assembly of the wheel they are configured to steer. In
some embodiments,
the double-acting hydraulic cylinder of each wheel assembly are hydraulically
connected to each
other, such that both pairs of wheels can operate to aid turning, providing a
four-wheel steering
system. The four wheel steering system may aid in sharp turns both during the
harvesting
operation as well as during transportation of the agricultural harvesting
head. Additionally, in
some embodiments the distance between the wheels is the same for both wheel
assemblies. This
may provide better support during sharp turns, and prevents rollover or
tipping from occurring in
some embodiments.
[0034] Sometimes when the user operating the combine makes a sharp turn (to
turn around
after completing one pass through the crop field, or to avoid objects or
trees), the harvesting head
wheels skid (i.e., the frictional interface between the point of the wheel
contacting the ground
becomes a dynamic frictional interface rather than a static frictional
interface which is present
when the wheel rolls). This may damage the wheels or any part of the axle
assembly by
introducing transverse thrust loads or other loads into the axle assembly and
the wheels. In some
cases, skidding may cause an undesirable load to be introduced into the
agricultural harvesting
head. Skidding may also cause ruts in the soil and dirt clumping. Therefore, a
harvesting head
which has wheels configured so that they do not skid when undergoing sharp
turns is
advantageous since it reduces the above mentioned problems associated with
skidding wheels.
In some embodiments, a force is applied to an outside wheel by a centering
bar. This force
implements a rollover feature which prevents the wheels from skidding and
reduces the problems
associated with skidding wheels described hereinabove. Additionally, this
force causes the
wheels to return back to a forward direction of travel after a turn.
[0035] Referring now to FIG. 1, an agricultural harvesting machine 100 is
shown according to
some embodiments. The agricultural harvesting machine 100 includes a combine
102 and a
harvesting head assembly 200 according to some embodiments. The harvesting
head assembly
200 is supported on one end by the combine 102, and supported above the ground
by wheels 224
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(see FIGS. 2-4) according to some embodiments. As the agricultural harvesting
machine 100
moves in harvesting direction of travel 104, the harvesting head assembly 200
severs the crop,
and transports it to combine 102 for processing and storage according to some
embodiments. In
some embodiments, harvesting head assembly 200 is detachably connected to
combine 102. It
should be noted that the present disclosure references a harvesting head
assembly 200 to be
transported, however, any other agricultural machine that requires
transportation may use the
steering/transportation-system described, and while the
steering/transportation system may be
used to transport harvesting head assembly 200 the use of harvesting head
assembly 200 is only
one possible application of the steering/transportation system.
[00361 Referring now to FIGS. 2A-B, the agricultural harvesting head assembly
200 is shown,
detached from combine 102. The agricultural harvesting head assembly 200 is
shown to include
wheel assembly 208 according to some embodiments. FIGS. 2A-B show only one
wheel
assembly 208, however the wheel assembly 208 on the opposite end of
agricultural harvesting
head assembly 200 may be symmetrical, so that whatever is said of the wheel
assembly 208
shown in FIGS. 2A-B may also be said of the wheel assembly 208 connected at
the opposite end
of the harvesting head assembly 200, according to some embodiments. FIGS. 2A-B
also show
coordinate system 108 for illustrative and explanatory purposes, having three
axes (104, 106, and
108) which may indicate direction of motion or direction in space. The three
axes 104, 106, and
108 are orthogonal to each other.
[0037] FIG. 2A shows wheel assembly 208 connected to the agricultural
harvesting head
assembly 200 in a harvesting mode of operation according to some embodiments.
Wheel
assembly 208 is shown to include wheels 224 and axle assembly 204 according to
some
embodiments. Wheels 224 rotatably connect to the axle assembly 204 and the
axle assembly 204
connects to the agricultural harvesting head assembly 200 according to some
embodiments. In
the harvesting mode of operation (shown in FIG. 2A), a centerline 220 which
extends through
the centers of wheels 224 is generally perpendicular to the harvesting
direction of travel 104 and
generally parallel to a longitudinal direction 106 of harvesting head assembly
200, according to
some embodiments. Wheels 224 are therefore configured to support the
harvesting head
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assembly 200 and roll in the harvesting direction of travel 104 according to
some embodiments.
When the harvesting head assembly 200 must be transported, wheel assemblies
208 are
configured to rotate 90 degrees as shown in FIG. 2B so that they generally
point in longitudinal
direction 106 according to some embodiments. In some embodiments, wheel
assemblies 208
rotate 90 degrees about centerline 212. Centerline 212 may extend generally
through the center
of axle assembly 204 and may be generally parallel to axis 108 according to
some embodiments.
In some embodiments, centerline 212 is half way in between the wheels 224.
When the wheel
assemblies 208 have both rotated 90 degrees, the harvesting head assembly 200
may be
transported in direction 106 (if the wheel assembly 208 shown is the front
wheel assembly 208),
or in the opposite direction (if the wheel assembly 208 shown is the rear
wheel assembly 208),
according to some embodiments. Harvesting head assembly 200 as shown in FIG.
2B may be
attached to a vehicle and may be transported on roads according to some
embodiments. In some
embodiments, harvesting head assembly 200 may be loaded into a trailer. In
some embodiments,
when harvesting head assembly 200 is loaded into the trailer, the wheel
assemblies 208 are
completely removed. In some embodiments, the wheel assemblies 208 are
retracted for trailer
transportation such that the wheel assemblies 208 do not interfere with the
trailer during
transportation.
[0038] FIGS 2A-B also show the wheels 224 spaced a distance 216 apart
according to some
embodiments. Both front and rear wheel assemblies 208 may have wheels 224
spaced distance
216 apart, according to some embodiments. In some embodiments, the wheel
assemblies 208
may have wheels 224 spaced apart at different distances. For example, the
wheel assembly 208
shown in FIGS. 2A-B may have wheels 224 spaced distance 216, while the wheel
assembly 208
at the opposite end of harvesting head assembly 200 may have wheels 224 spaced
a distance
greater than distance 216 according to some embodiments. In some embodiments,
wheel
assembly 208 at the opposite end of harvesting head 200 may have wheels 224
spaced a distance
less than distance 216. In some embodiments, the wheel assembly 208 with the
wheels 224
spaced a greater distance apart than the opposite wheel assembly 208 may be
the "front" of the
harvesting head assembly 200 during transportation. In some embodiments, the
wheel assembly
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208 with the wheels 224 spaced a lesser distance apart than the opposite wheel
assembly 208
may be the "front" of the harvesting head assembly 200 during transportation.
In some
embodiments, the distance between wheels 224 is the same for both wheel
assemblies 208 and
either wheel assembly 208 may be the "front" or "rear" of the harvesting head
assembly 200
during transportation. In some embodiments, the distance between wheels 224 is
the same for
both wheel assemblies 208 and one of the wheel assemblies 208 may be the
"front" while the
other wheel assembly 208 may be the "rear."
[0039] Referring still to FIGS. 2A-2B, the wheels 224 are shown spaced
distance 216 apart. In
some embodiments, distance 216 is substantially greater than the width of the
harvesting head
assembly 200 in direction 104. In some embodiments, distance 216 is
substantially equal to the
width of harvesting head assembly 200 in direction 104. This provides a stable
support for the
harvesting head assembly 200 during transportation, according to some
embodiments. When the
harvesting head assembly 200 is transported and goes around a sharp turn,
inertial forces may
cause the harvesting head assembly 200 to tip. For example, if the wheel
assembly 208 shown in
FIGS. 2A-B is the "front" wheel assembly, and the user makes a left turn,
there may be a
component of an inertial force from the center of gravity of the harvesting
head assembly 200 in
the 104 direction. This force in the 104 direction may produce a moment about
the 106 axis.
Advantageously, the wide wheel distance 216 provides a counter-moment
according to some
embodiments. In the case of a left turn, the left wheel of the wheel assembly
208 (the right
wheel from the vehicle operator's perspective) may provide a reactionary
moment to counter the
tipping moment. The moment arm of the reactionary moment may be up to half of
the distance
216 (i.e., the distance from the center of the left wheel 224 to the center of
the axle assembly 204
in the 104 direction). The rear wheel assembly 208 may also provide a counter-
moment to the
tipping moment, according to some embodiments. In some embodiments, both the
front wheel
assembly 208 and the rear wheel assembly 208 may provide a counter-moment to
the tipping
moment. The distance 216 provides a longer moment arm to counter the tipping
moment which
may occur during sharp turns or if the vehicle operator makes a turn at a high
speed, since
making a turn at a high speed produces a large inertial force which may cause
a tipping moment.
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Both the front and the rear wheel assemblies 208 may have equal distances 216
and distance 216
may be substantially equal to or greater than the width of the agricultural
machine in the 104
direction. Advantageously, this reduces the tendency of the agricultural
machine (e.g.,
harvesting head assembly 200 as shown in FIGS. 1-2B) to tip during turns.
Tipping may cause
uneven distribution or excessive magnitude of loads to the axle assemblies 204
and the wheel
assemblies 208 which may damage components in the axle assembly 204 or wheel
assemblies
208 which may not be designed to undergo these excessive loads. Additionally,
if the
agricultural machine tips over completely (i.e., rollover), this may cause
severe damage to the
agricultural machine, which may be expensive and time-consuming to repair.
While the
agricultural machine is being repaired, it cannot be used for agricultural
purposes, and this can
cause additional costs. Reducing the tendency of the agricultural machine to
tip while making
turns during transportation reduces the likelihood of the agricultural machine
rolling over, and
enables the vehicle operator to make sharper turns without fear of tipping the
agricultural
machine. This also enables the vehicle operator greater mobility during
transportation, and
enables the vehicle operator to take routes which may require sharp turns.
Embodiments in the
present disclosure provide a solution to this problem by providing a wide
wheel base which
reduces the likelihood and magnitude of tipping and may reduce the likelihood
of rollover
occuring.
100401 Referring now to FIGS. 3-4, the axle assembly 204 of the wheel assembly
208 is shown
in greater detail according to some embodiments. In FIGS. 3-4, only one axle
assembly 204 is
shown, however it should be understood that everything said of the axle
assembly 204 shown in
FIGS. 3-4 may be said of the axle assembly 204 at the opposing end of
harvesting head assembly
200 or more generally the agricultural machine. Axle assembly 204 is shown to
include
horizontal axle 226, header 256, tongue 244, double-action cylinder 230,
struts 240, cylinder
mount 236, tie rods 228, centering bar 252, and spring 248 according to some
embodiments.
Double-action cylinder 230 may be generally horizontally oriented, and may be
generally
parallel to horizontal axle 226.
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[0041] In some embodiments, double-action hydraulic cylinder 230 has outer
tubular member
232 (e.g., a barrel) which pivotally connects to cylinder mount 236 and inner
tubular member
234 (e.g., a rod) which pivotally connects to tongue 244. Cylinder mount 236
may be fixedly
connected to horizontal axle 226 or may be intergrally formed with horizontal
axle 226,
according to some embodiments. Tongue 244 is configured to pivot about pin
joint 254
according to some embodiments. Tongue 244 pivotally connects to tie rods 228
at joint 258
according to some embodiments. According to some embodiments, as double-action
cylinder
230 expands or retracts, tongue 244 pivots about pin joint 254. For example,
when double-action
cylinder 230 expands, the end of tongue 244 which pivotally connects to the
inner tubular
member 234 moves to the left, according to some embodiments. As the end of
tongue 244 which
pivotally connects to inner tubular member 234 moves to the left due to the
expansion of double-
action cylinder 230, tongue 244 pivots about pin joint 254, resulting in the
end of tongue 244
which pivotally connects to tie rods 228 moving to the right, according to
some embodiments.
The pivoting of the tongue 244 may cause the tie rods 228 to move to the
right, thus steering the
wheels 224, according to some embodiments. Likewise, as the end of tongue 244
which
pivotally connects to inner tubular member 234 moves to the right due to the
retraction of
double-action cylinder 230, tongue 244 pivots about pin joint 254, resulting
in the end of tongue
244 which pivotally connects to tie rods 228 moving to the left, according to
some embodiments.
In some embodiments, the tongue 244 is driven to pivot by the vehicle or
another external force
applied to the tongue, and the pivoting motion of the tongue 244 drives the
expansion or
retraction of double-action cylinder 230 in the same configuration as
discussed above.
[0042] Double-action cylinder 230 is shown to include inlet/outlet ports 260
and 262 according
to some embodiments. In some embodiments, inlet/outlet ports 260 and 262 are
configured to
allow the flow of hydraulic fluid into or out of two chambers of double-action
cylinder 230. In
some embodiments, the flow of hydraulic fluid in and out of inlet/outlet ports
260 and 262 is
driven by the pivoting motion of tongue 244 which may be driven by the
vehicle. In some
embodiments, the flow of hydraulic fluid in and out of inlet/outlet ports 260
and 262 causes the
double-action cylinder 230 to expand or retract and drives the pivoting of the
tongue 244. In
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some embodiments, inlet/outlet ports 260 and 262 are configured to allow
hydraulic fluid to flow
between the front and rear double-action cylinders 230. In some embodiments,
inlet/outlet ports
260 and 262 are configured to allow the hydraulic fluid to flow between either
one or both the
front and rear double-action cylinders 230 and a hydraulic fluid reservoir or
a pump. Inlet/outlet
ports 260 and 262 may each allow the inflow or outflow of hydraulic fluid
according to some
embodiments.
[0043] In some embodiments, the inlet/outlet ports 260 and 262 are configured
to interface
with hydraulic lines to facilitate the flow of hydraulic fluid into and out of
the double-action
cylinder 230. For example, the front double-action cylinder 230 may be
configured to be driven
into a more retracted state by the tongue 244, thus expelling hydraulic fluid
from one chamber of
the front double-action cylinder 230 according to some embodiments. The
hydraulic fluid
expelled from one chamber of the front double-action cylinder 230 may be
directly introduced to
a chamber of the rear double-action cylinder 230 causing the rear double-
action cylinder 230 to
expand. In some embodiments, the front double-action cylinder 230 may be
driven into a more
expanded state by the tongue 244, causing hydraulic fluid to be introduced
into one chamber of
the front double-action cylinder 230. According to some embodiments, the
hydraulic fluid
introduced into one chamber of the front double-action cylinder 230 may be
drawn directly from
the chamber of the rear double-action cylinder 230, causing the rear double-
action cylinder 230
to be driven into a more retracted state. The flow of the hydraulic fluid
between the front and
rear double-action cylinders 230 may be facilitated by the inlet/outlet ports
260 and 262 of the
double-action cylinders 230, as well as hydraulic lines connecting the
inlet/outlet ports 260 and
262 of the front and rear double-action cylinders 230.
[0044] Double-action cylinders 230 may include a piston attached to inner
tubular member
234, configured to sealingly interface with an inner diameter of outer tubular
member 232
according to some embodiments. In some embodiments, a seal may be used to
sealingly
interface an outer diameter of the piston to the inner diameter of the outer
tubular member 232.
The seal may be an 0-ring made of rubber, or any other seal which prevents the
flow of fluid
between the interface of the seal and the inner diameter of outer tubular
member 232. Inner
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tubular member 234 and the piston attached to it may longitudinally travel
within the outer
tubular member 232 according to some embodiments. In some embodiments, the end
of outer
tubular member 232 which inner tubular member 234 protrudes from is sealed,
such that inner
tubular member 234 can expand and retract (i.e., travel longitudinally within
outer tubular
member 232), without hydraulic fluid leaking from the end which inner tubular
member 234
protrudes. In some embodiments, the seal interface between the piston attached
to the inner
tubular member 234 and the outer tubular member 232 divides the double-action
cylinder 230
into two chambers.
[0045] The first chamber may be defined between the end of the outer tubular
member 232
which the inner tubular member 234 protrudes from, the inner walls of the
outer tubular member
232, and the sealed interface between the piston attached to the inner tubular
member 234 and
the inner diameter of the outer tubular member 232, according to some
embodiments. The
second chamber may be defined between an end of the outer tubular member 232
opposite the
end which the inner tubular member 234 protrudes from, the inner walls of the
outer tubular
member 232, and the sealed interface between the piston attached to the inner
tubular member
234 and the inner diameter of the outer tubular member 232, according to some
embodiments. In
some embodiments, as hydraulic fluid flows into the second chamber of double-
action cylinder
230, hydraulic fluid leaves the first chamber of double-action cylinder 230,
and the double-action
cylinder 230 expands. In some embodiments, as hydraulic fluid flows into the
first chamber of
double-action cylinder 230, hydraulic fluid leaves the second chamber of
double-action cylinder
230, and the double-action cylinder 230 retracts. The inlet/outlet port 260
may be the inlet/outlet
port for the first chamber, and the inlet/outlet port 262 may be the
inlet/outlet port 262 for the
second chamber, according to some embodiments.
[0046] In some embodiments, the front and rear double-action cylinders 230 may
be
hydraulically linked, such that when hydraulic fluid leaves the first chamber
and enters the
second chamber of the front double-action cylinder 230 (i.e., the front double-
action cylinder 230
expands), hydraulic fluid enters the first chamber and leaves the second
chamber of the rear
double-action cylinder 230 (i.e., the rear double-action cylinder 230
retracts). In some
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embodiments, the front and rear double-action cylinders 230 may be
hydraulically linked, such
that when hydraulic fluid leaves the second chamber and enters the first
chamber of the front
double-action cylinder 230 (i.e., the front double-action cylinder 230
retracts), hydraulic fluid
enters the second chamber and leaves the first chamber of the rear double-
action cylinder 230
(i.e., the rear double-action cylinder expands). In some embodiments, the
first chamber of the
front double-action cylinder 230 is hydraulically linked to the second chamber
of the rear
double-action cylinder 230 and the second chamber of the front double-action
cylinder 230 is
hydraulically linked to the first chamber of the rear double-action cylinder
230.
[0047] As stated above, the flow of fluid between the first chamber of the
front double-action
cylinder 230 and the second chamber of the rear double-action cylinder 230,
and the flow of
fluid between the second chamber of the front double-action cylinder 230 and
the first chamber
of the rear double-action cylinder 230 may be facilitated by the inlet/outlet
ports 260 and 262 and
hydraulic lines, according to some embodiments. For example, a first hydraulic
line may be
attached to the inlet/outlet port 260 of the front double-action cylinder 230
and the inlet/outlet
port 262 of the rear double-action cylinder 230, while a second hydraulic line
may be attached to
the inlet/outlet port 262 of the front double-action cylinder 230 and the
inlet/outlet port 260 of
the rear-double action cylinder 230, according to some embodiments. This may
produce a closed
fluid circuit between the inlet/outlet ports 260 and 262 of the front and rear
double-action
cylinders 230, with the front double-action cylinder 230 being driven (i.e.,
expanded or retracted)
by the tongue 244 driven by the motion of the vehicle, and the rear double-
action cylinder 230
being driven (i.e., expanded or retracted) due to the hydraulic fluid
transferred to or from the first
or second chambers of the front double-action hydraulic cylinder 230,
according to some
embodiments.
[0048] Tongue 244 may be produced from steel, and may be generally square-
shaped in its
cross section, according to some embodiments. In some embodiments, the cross-
sectional shape
of tongue 244 may be generally I-shaped, generally rectangular, etc., or any
other shape.
According to some embodiments, tongue 244 may include connecting portion 246
integrally
formed with tongue 244 near its end. Connecting portion 246 may include a
through-hole and
CA 3044206 2019-05-24
may be configured to attach to a beam for towing or transportation purposes in
some
embodiments. In some embodiments, the beam may connect to a trailer hitch on
the vehicle, and
the other end of the beam may connect to the connecting portion 246 with a
removable pin. The
beam may act as a tensile load-carrying member, transferring a towing force
from the vehicle to
the tongue 244 to tow the agricultural machine according to some embodiments.
In some
embodiments, when the vehicle turns, the tongue 244 (in the front axle
assembly 204) is caused
to pivot by the turning motion of the vehicle, transferred through the beam.
This may cause
tongue 244 to drive the expansion/retraction of the front double-action
cylinder 230. In some
embodiments, tongue 244 is connected to tongue halves 266. Tongue halves 266
may be pinned
to tongue 244 with removable pin 268. In some embodiments, tongue halves 266
are integrally
formed with tongue 244. Tongue halves 266 may be positioned between centering
bar 252 and
tongue 244 according to some embodiments. In some embodiments, centering bar
252, tongue
halves 266, and tongue 244 are all pinned with pin 268. In some embodiments,
tongue halves
266 are integrally formed with centering bar 252. Tongue halves 266 may extend
substantially
the entire length of tongue 244 according to some embodiments. Tongue halves
266 may be
made from steel and may have a generally square or generally rectangular cross-
sectional shape.
In some embodiments, tongue halves 266 are integrally formed with tongue 244.
[0049] Tie rods 228 are configured to steer wheels 224 to determine a turn
direction according
to some embodiments. Therefore, the expansion and retraction of double-action
cylinder 230
may determine the turn direction, according to some embodiments. In some
embodiments, tie
rods 228 are generally circular in their cross-sectional shape. In some
embodiments, the cross-
sectional shape of tie rods 228 may be generally oval, generally square,
generally rectangular, or
any other shape. Tie rods 228 may be substantially the same length, according
to some
embodiments. Tie rods 228 may have eye portions near their ends configured to
connect to the
joint 258 on one end and to connect to wheel hub 222 on the other end.
[0050] Referring still to FIGS. 3-4, axle assembly 204 is shown to include
struts 240. Struts
240 may be made of steel and may have cross-sectional shape that is I-shaped
according to some
embodiments. In some embodiments, struts 240 may have a cross-sectional shape
that is
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generally rectangular, generally circular, etc. According to some embodiments,
struts 240 may
have through-holes distributed along the longitudinal length, which may
decrease the weight and
material of the struts 240. In some embodiments, struts 240 are configured to
connect on one
end to strut mounts 242 and connect on their other end to header 256. Struts
240 may be
removable according to some embodiments. In some embodiments, struts 240
connect to strut
mounts 242, which connects to strut connector 264. Strut connector 264
connects the strut
mounts 242 to horizontal axle 226, according to some embodiments. According to
some
embodiments, the connection between the strut connector 264 and the horizontal
axle 226 is a
fixed connection. Horizontal axle 226 may have axle reinforcement 270 which
provides
additional strength to horizontal axle 226 according to some embodiments. In
some
embodiments, the horizontal axle 226 may be generally circular.
[0051] In some embodiments, the double-action cylinder 230 of the two axle
assemblies 204
are hydraulically connected. Since both axle assemblies 204 have the same
general
configuration, both axle assemblies 204 are configured to turn wheels 224,
resulting in a four-
wheel steering system. Double-action cylinders 230 are configured to
hydraulically connect to
each other to produce a turning radius smaller than if only one of the wheel
assemblies 208 were
steerable. According to some embodiments, the expansion and retraction amounts
of the double-
action cylinders 230 are equal. For example, when double-action cylinder 230
shown in FIG. 3
expands 1 cm, the other double-action cylinder 230 may be configured to expand
1 cm as well
according to some embodiments. In some embodiments, the expansion and
retraction of the
double-action cylinders 230 are not equal. For example, when double-action
cylinder 230 shown
in FIG. 3 expands 1 cm, the other double-action cylinder 230 (not shown) may
be configured to
expand 0.5 cm according to some embodiments. According to some embodiments,
the
expansion and retraction of the double-action cylinders 230 are inversely
proportional. For
example, when double-action cylinder 230 shown in FIG. 3 expands 1 cm, the
other double-
action cylinder 230 may be configured to retract 1 cm (or 0.5 cm, or 1.5 cm,
etc.) according to
some embodiments. In some embodiments, the length of the tongue 244 is not
equal between the
two axle assemblies 204. Therefore, the same amount of expansion or retraction
of the double-
17
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action cylinders 230 may not correspond to equal angular pivot displacements
of the tongue 244
according to some embodiments. In some embodiments, the relationship between
the angular
displacement of the front wheels 224 and the rear wheels 224 due to the
expansion or retraction
of double-action cylinder 230 is linear (e.g., when the front wheels rotate 30
degrees, the rear
wheels rotate 30 degrees in a direction to produce the same turn as the front
wheels). In some
embodiments, the relationship between the angular displacement of the front
wheels 224 and the
rear wheels 224 due to the expansion or retraction of the double-action
cylinder 230 is inversely
linear (e.g., when the front wheels rotate 30 degrees, the rear wheels rotate -
30 degrees). In some
embodiments, the relationship between the angular displacement of the front
wheels 224 and the
rear wheels 224 due to the expansion or retraction of the double-action
cylinder 230 may be non-
linear (e.g., when the front wheels rotate 30 degrees, the rear wheels rotate
15 degrees, when the
front wheels rotate 60 degrees, the rear wheels rotate 30 degrees, when the
front wheels rotate 70
degrees the rear wheels rotate 35 degrees, etc.). Some or any of these
relationships between the
rotation of the front wheels 224 and the rear wheels 224 due to the expansion
and retraction of
the double-action cylinders 230, may be obtained by using different lengths of
the tongue 244,
the outer tubular member 232, or the inner tubular member 234.
[0052] In some embodiments, the tongue 244 drives the double-action cylinder
230. For
example, if the tongue 244 is connected to a vehicle and the vehicle makes a
turn, this will cause
the tongue 244 to move and to actuate double-action cylinder 230. In some
embodiments, the
double-action cylinder 230 which is driven by the tongue 244 only occurs on
the front axle
assembly 204. The rear axle assembly 204 may include double-action cylinder
230 that is
hydraulically linked to the operation of the double-action cylinder 230 of the
front axle assembly
204 according to some embodiments. The tongue is configured to pivot due to
the direction of
turn of the vehicle, and to expand or contract the front double-action
cylinder 230 based on the
movement of the tongue 244, according to some embodiments. In some
embodiments, the
tongue 244 pivots in direction and magnitude proportional to the turn of the
vehicle. For
example, if the vehicle makes a sharp right turn, tongue 244 may pivot +35
degrees, according to
some embodiments. In some embodiments, if the vehicle makes a slight left
turn, tongue 244
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may pivot -15 degrees. In some embodiments, the direction and magnitude of the
pivoting of the
tongue 244, which is proportional to the magnitude and direction of turn of
the vehicle, may
cause the front double-action cylinder 230 to expand or retract (direction) a
certain length
(magnitude). According to some embodiments, the rear double-action cylinder
230 is
hydraulically linked to the front double-action cylinder 230 and expands or
retracts based on the
operation of the front double-action hydraulic cylinder 230 (i.e., the rear
double-action cylinder
230 expands or retracts due to the fluid transfer from the front double-action
cylinder 230). In
this way, the direction and magnitude of the turn of the vehicle is
transferred to the front double-
action cylinder 230 through the tongue 244, and to the rear double-action
cylinder 230, resulting
in four-wheel steering according to some embodiments. According to some
embodiments, the
relationship between the operation of the front double-action cylinder 230 (as
driven by the
tongue 244) and the rear double-action cylinder 230 is any of the
relationships discussed above
(e.g., linear, non-linear, based on expansion or retraction length, based on
turn angle of wheels,
etc.). For example, in some embodiments, when the vehicle makes a sharp right
turn, the tongue
244 may pivot +35 degrees, causing the front double-action cylinder 230 to
expand a length of 3
cm, while the rear double-action cylinder 230 may retract only 1.5 cm.
[0053] In some embodiments, the double-action cylinders 230 are hydraulically
connected in
their operation to each other through a hydraulic fluid circuit. In some
embodiments, the
relationship between the expansion and retraction of the front and rear double-
action cylinders
230 may be related to fluid quantity. For example, as 10 mL of hydraulic fluid
leaves or enters
the front double-action cylinder 230 as it retracts or expands, 10 mL of
hydraulic fluid may leave
or enter the rear double-action cylinder 230 causing it to expand or retract
and vice versa. In
some embodiments, the relationship between the fluid entering or leaving the
front double-action
cylinder 230 and the fluid entering or leaving the rear double-action cylinder
230 is non-linear.
In some embodiments, a controller may be present in the hydraulic fluid
circuit, configured to
control the operation of a pump. The controller may be configured to control
the pump to pump
fluid between a fluid reservoir and the front and/or rear double-action
cylinders 230. The
controller may pump fluid between the front and/or rear double-action
cylinders 230 based on
19
CA 3044206 2019-05-24
the operation of the front or rear double-action cylinders 230 which may be
determined by the
pivoting of the tongue 244 which is directly related to the magnitude and turn
of the vehicle. In
some embodiments, the controller may receive information from a wheel speed
sensor or a
magnitude of turn sensor and adjust the operation of the pump (or the
relationship between the
rotation of the front and rear wheels 224) based on information received from
the wheel speed
sensor or the magnitude of turn sensor. For example, the controller may be
configured to control
the pump to expand or retract the rear double-action cylinder 230 only during
sharp turns when
four-wheel steering is necessary.
[0054] Due to the similar configurations of the front and rear wheel
assemblies 208, both
wheel assemblies 208 can steer due to the double-action cylinder 230,
according to some
embodiments. In some embodiments, this results in four-wheel steering. Four-
wheel steering
provides many advantages. For example, when the agricultural harvesting head
200 (or any
other agricultural machine) is being transported behind a vehicle, the driver
may need to make
sharp turns in order to avoid obstacles in the road or to even simply make a
sharp turn around a
corner. Agricultural machines that are being transported behind vehicles can
often be very long
(typically much longer than the average length of a truck), and this can make
transporting the
agricultural machines very difficult. If the vehicle operator cannot make a
sharp turn on a route,
it may limit the route that the operator can take, and this can add additional
cost and time to
transporting the agricultural machine. If the operator decides to take a route
with a sharp turn or
must make a sharp turn to avoid something in the road, the rear wheels may
skid if a two-wheel
steering system is used. The desired turn may be too sharp for the two-wheel
steering system,
and this may cause the rear wheels to drag along the ground. This is
undesirable since it may
wear out the tires, and may introduce transverse loads into the axle which may
damage the axle,
the wheel bearings, or any other part of the axle assembly. In some
embodiments, if the desired
turn is too sharp for the two-wheel steering system (e.g., a turn exceeds
turning limits of the two-
wheel steering system), tongue 244 may receive an excessive bending force and
if the bending
force becomes too great, tongue 244 may bend (e.g., deform). Wheel
dragging/scrubbing may
also occur during harvesting or while using the agricultural machine in field
mode if the operator
CA 3044206 2019-05-24
makes a turn which is too sharp. This can cause the same problems as when a
sharp turn is made
on the road (transverse loads, wearing of tires, etc.), and additionally may
produce ruts in the soil
or forcibly introduce dirt into the axle system. Using a four-wheel steering
system as described
above may solve these problems. The four-wheel steering system enables the
vehicle driver to
make sharp turns while during transportation, and also enables the
agricultural machine operator
to make sharp turns when using the agricultural machine in a field.
Additionally, the four-wheel
steering may decrease the likelihood of tipping at high speeds. This may
enable the vehicle
operator to travel faster during transportation without risk of rolling over
and damaging the
agricultural machine. Advantageously, this may reduce in the transportation
time, enabling
faster transportation.
[0055] Referring still to FIGS. 3-4, the axle assembly 204 is shown to include
spring 248,
which is connected on one end to spring mount 250, and connected to centering
bar 252 on the
other end, according to some embodiments. In some embodiments, centering bar
252 is pinned
to tongue 244. Spring 248 may in some embodiments provide a centering force
for the rollover
function while in field mode. In some embodiments, spring 248 is configured to
provide a force
to the outside wheel 224 (the only wheel shown in FIG. 3) during a turn. For
example, when the
spring 248 is expanded due to the expansion of double-action cylinder 230, it
produces a tensile
force between the centering bar 252 and the spring mount 250. This force is
transmitted through
centering bar 252, tongue 244, and the left tie rod 228 of FIG. 3 to the left
(outside) wheel 224 of
FIG. 3 according to some embodiments.
[0056] In some embodiments, the front double-action cylinder 230 is connected
to the tongue
244 which pivots about pin joint 254. The tongue 244 may be driven by the
vehicle through the
beam connected to connecting portion 246 according to some embodiments. As the
vehicle
makes a turn, the tongue 244 is caused to pivot, and the front double-action
cylinder 230 expands
or retracts according to some embodiments. The tongue 244 is also connected to
the tie rods
228, and the pivoting of the tongue 244 causes the tie rods 228 to move and
steer the wheels 224,
according to some embodiments. As the front double-action cylinder 230 expands
or retracts,
hydraulic fluid enters or leaves the first or second chamber of the front
double-action cylinder
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230, through inlet/outlet ports 260 and 262 according to some embodiments.
Hydraulic fluid is
transferred to or from the front double-action cylinder 230 and the rear-
double action cylinder
230 through hydraulic fluid lines connected to the inlet/outlet ports 260 and
262 of the front and
rear double-action cylinders 230 according to some embodiments. When hydraulic
fluid is
transferred to and from the front double-action cylinder 230 and the rear
double-action cylinder
230, rear double-action cylinder 230 expands or retracts due to the transfer
of hydraulic fluid into
and out of the first and second chambers (or the second and first chambers) of
double-action
cylinder 230 respectively, according to some embodiments. The expansion or
retraction of rear
double-action cylinder 230 causes the tongue 244 of the rear wheel assembly
208 to pivot,
according to some embodiments. When the tongue 244 of the rear wheel assembly
208 pivots
due to the expansion or retraction of rear double-action cylinder 230, the
tongue 244 of the rear
wheel assembly 208 drives the tie rods 228 of the rear wheel assembly 208,
according to some
embodiments. The tie rods 228 of the rear wheel assembly 208 are connected to
the wheels 224
of the rear wheel assembly 208, according to some embodiments. As the tie rods
228 of the rear
wheel assembly 208 are driven by the tongue 244 of the rear wheel assembly
208, the tie rods
228 of the rear wheel assembly 208 steer the wheels 224 of the rear wheel
assembly 208,
according to some embodiments. Therefore, as the front wheel assembly 208 is
steered to make
a turn, the rear wheel assembly 208 is also steered in a direction conducive
to the turn of the
vehicle, according to some embodiments.
[0057] Another advantage of the present invention is that both the wheel
assemblies 208 may
be symmetrical, according to some embodiments. Therefore, when parts are
manufactured or
must be replaced, the same parts can be used for both wheel assemblies 208.
Often times,
agricultural machines that have wheels for transporting will use different
configurations for the
front and rear wheel assemblies and unique parts must be manufactured for both
of these wheel
assemblies. The present invention presents a standardized wheel assembly 208
that may be used
on the front and rear, and may reduce tipping and implement four-wheel
steering, according to
some embodiments.
22
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[0058] While this specification contains many specific implementation details,
these should not
be construed as limitations on the scope of what may be claimed, but rather as
descriptions of
features specific to particular implementations. Certain features described in
this specification in
the context of separate implementations can also be implemented in combination
in a single
implementation. Conversely, various features described in the context of a
single
implementation can also be implemented in multiple implementations separately
or in any
suitable sub combination. Moreover, although features may be described above
as acting in
certain combinations and even initially claimed as such, one or more features
from a claimed
combination can in some cases be excised from the combination, and the claimed
combination
may be directed to a subcombination or variation of a subcombination.
[0059] Although the present disclosure is illustrated by the example of a
header of a harvest
machine, the present disclosure may be applied to various machines that are
similar to the header
of a harvest machine that need to be transported between different field
sites.
[0060] It should be understood that while the use of words such as desirable
or suitable utilized
in the description above indicate that the feature so described may be more
desirable, it
nonetheless may not be necessary and embodiments lacking the same may be
contemplated as
within the scope of the invention, the scope being defined by the claims that
follow. In reading
the claims, it is intended that when words such as "a," "an," or "at least
one" are used there is no
intention to limit the claim to only one item unless specifically stated to
the contrary in the claim.
[0061] It should be noted that certain passages of this disclosure can
reference terms such as
"first" and "second" in connection with side and end, etc., for purposes of
identifying or
differentiating one from another or from others. These terms are not intended
to merely relate
entities (e.g., a first side and a second side) temporally or according to a
sequence, although in
some cases, these entities can include such a relationship. Nor do these terms
limit the number
of possible entities (e.g., sides or ends) that can operate within a system or
environment.
[0062] The terms "connected" and the like as used herein mean the joining of
two components
directly or indirectly to one another. Such joining may be stationary (e.g.,
permanent) or
23
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moveable (e.g., removable or releasable). Such joining may be achieved with
the two
components or the two components and any additional intermediate components
being integrally
formed as a single unitary body with one another or with the two components or
the two
components and any additional intermediate components being attached to one
another.
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