Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02665589 2010-11-25
COMBINE HEADER WITH GAUGE WHEELS TO CONTROL CUT HEIGHT
This invention relates to a header for a combine harvester where the
header includes ground engaging gauge wheels to provide stability to the
header
when cutting off the ground.
BACKGROUND OF THE INVENTION
Typically headers for combine harvesters are mounted on the feeder
house of the combine with the mounting arrangement providing a floating action
of
the header relative to the feeder house so that the cutter bar can rest on the
ground
and float over the ground in a cutting action.
In some cases an automatic header height control system is provided
with header to feeder house position indicators which allow the header to
automatically adjust flotation to ground conditions, eliminating the need for
the
operator to make constant adjustments.
In some cases however it is desirable to provide a cutting action at a
position where the cutter bar is at a raised height so that no stability is
provided by
engagement with the ground. In this arrangement, the header is typically
provided
with ground engaging gauge wheels at or adjacent respective ends of the header
to
gauge a required height from the ground
This is normally done with gauge wheels that carry part of the weight of
the header, with the rest carried by the main suspension, with springs on the
gauge
wheels in order to absorb the high shock loads when hitting a bump, and in
order to
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provide some adjustment of cutter bar height while maintaining wheel
engagement
with the ground.
One of the issues with this system is to provide sufficient stability of the
header when cutting at the raised height and while traveling at higher cutting
speeds.
Some of the different ways to do this and their problems include:
Gauge wheel with a soft spring, however this does not provide enough
header stability;
Gauge wheel with a stiff spring, this provides more stability but the stiff
spring action can "throw" the header up to an unacceptable degree;
Gauge wheel with a stiff spring as above but combined with a shock
absorber, this is better than the spring alone as above, but there remain
issues with
stability;
Gauge wheel mounted solid on the header, this does not allow
changing the height of the cutter bad while maintaining ground contact with
the
gauge wheel s and causes huge shock loads;
Ground sensors in place of the gauge wheels to provide direct control
signals to the suspension system, but this system does not react quickly
enough to
provide the required control and stability. Also, with ground sensors the
header has
to be positioned on a bottom stop when cutting off the ground so that the
header is
effectively fixed relative to the combine. As a result, when the combine goes
over
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bumps, the oscillation of the combine causes the header to move up and down,
causing an irregular cut.
SUMMARY OF THE INVENTION
It is one object of the invention to provide a header for a combine
harvester where the header includes ground engaging gauge wheels to provide
stability to the header when cutting off the ground.
According to one aspect of the invention there is provided a header
assembly for attachment to a combine harvester comprising:
a header having a cutter bar for cutting standing crop and a crop
transport device for transporting the standing crop inwardly from ends of the
header
to a collection location for feeding to the combine harvester;
an adapter for mounting the header on a feeder house of the combine
harvester;
the adapter being arranged such that the crop at the collection location
is fed through the feeder house to the combine harvester;
the adapter being arranged such that the header is carried on the
feeder house for movement of the header with the combine harvester over the
field
to be harvested;
at least two ground engaging gauge wheels on the header one on
each side of the adapter;
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each gauge wheel being mounted on the header for up and down
adjustment movement of a position of the gauge wheel relative to the header to
control the height of the cutter bar of the header from the ground;
an adjustable link operable by a control switch arranged to be located
in a cab of the combine harvester to adjust the position of the gauge wheel
relative
to the header to a required position so as to adjust a height of cut of the
cutter bar;
wherein the gauge wheels are mounted on the header such that, when
adjusted to the required position, the gauge wheels are fixed relative to the
header
substantially without any suspension floating movement relative thereto;
a suspension system for carrying the header on the adapter;
the suspension system being arranged such that a major part of the
weight of the header is carried on the feeder house and a smaller part is
carried on
the gauge wheels;
a distance sensor for sensing changes in distance between a point on
the header and a point on the adapter as the header moves upwardly and
downwardly relative to the adapter and for generating a signal indicative of
the
sensed changes in said distance;
and an automatic header height control system which receives the
signal from the distance sensor and acts to raise and lower the feeder house
in
response to the signal from the distance sensor so as to raise and lower the
feeder
house relative to the header and attempt to maintain said distance at a
required set
value.
CA 02665589 2010-11-25
According to a second aspect of the invention there is provided a
header assembly for attachment to a combine harvester comprising:
a header having a cutter bar for cutting standing crop and a crop
transport device for transporting the standing crop inwardly from ends of the
header
5 to a collection location for feeding to the combine harvester;
an adapter for mounting the header on a feeder house of the combine
harvester;
the adapter being arranged such that the crop at the collection location
is fed through the feeder house to the combine harvester;
the adapter being arranged such that the header is carried on the
feeder house for movement of the header with the combine harvester over the
field
to be harvested;
at least two ground engaging gauge wheels on the header one on
each side of the adapter;
each gauge wheel being mounted on the header for up and down
adjustment movement of a position of the gauge wheel relative to the header to
control the height of the cutter bar of the header from the ground;
an adjustable link operable by a control switch arranged to be located
in a cab of the combine harvester to adjust the position of the gauge wheel
relative
to the header to a required position so as to adjust a height of cut of the
cutter bar;
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wherein the gauge wheels are mounted on the header such that, when
adjusted to the required position, the gauge wheels are fixed relative to the
header
substantially without any suspension floating movement relative thereto;
a suspension system for carrying the header on the adapter;
the suspension system including at least two mechanical springs which
flex to allow allowing movement of the header at least upwardly and downwardly
relative to the adapter;
the suspension system being arranged such that a major part of the
weight of the header is carried on the feeder house and a smaller part is
carried on
the gauge wheels;
a distance sensor for sensing changes in distance between a point on
the header and a point on the adapter as the header moves upwardly and
downwardly relative to the adapter and for generating a signal indicative of
the
sensed changes in said distance;
and an automatic header height control system which receives the
signal from the distance sensor and acts to raise and lower the feeder house
in
response to the signal from the distance sensor so as to raise and lower the
feeder
house relative to the header and attempt to maintain said distance at a
required set
value.
According to a third aspect of the invention there is provided a
combination comprising:
a crop harvesting machine;
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and a header assembly for attachment to the crop harvesting machine;
the crop harvesting machine comprising:
a vehicle for movement over ground having a standing crop for
harvesting, the vehicle including a cab for an operator of the crop harvesting
machine;
a support assembly for carrying the header assembly;
the header assembly comprising:
a header having a cutter bar for cutting standing crop and a crop
transport device for transporting the standing crop inwardly from ends of the
header
to a collection location for feeding to the combine harvester;
a connector for mounting the header on the support assembly of the
crop harvesting machine;
the connector being arranged such that the crop at the collection
location is fed through the support assembly to the crop harvesting machine;
the connector being arranged such that the header is carried on the
support assembly for movement of the header with the crop harvesting machine
over the field to be harvested;
at least two ground engaging gauge wheels on the header one on
each side of the adapter;
each gauge wheel being mounted on the header for up and down
adjustment movement of a position of the gauge wheel relative to the header to
control the height of the cutter bar of the header from the ground;
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an adjustable link operable by a control switch arranged to be located
in a cab of the combine harvester to adjust the position of the gauge wheel
relative
to the header to a required position so as to adjust a height of cut of the
cutter bar;
wherein the gauge wheels are mounted on the header such that, when
adjusted to the required position, the gauge wheels are fixed relative to the
header
substantially without any suspension floating movement relative thereto;
the connector and the support assembly providing a suspension
system to allow suspension movement of the header at least upwardly and
downwardly relative to the crop harvesting machine;
the suspension system being arranged such that a major part of the
weight of the header is carried on the crop harvesting machine and a smaller
part is
carried on the gauge wheels;
a distance sensor for sensing changes in distance between a point on
the header which moves with the header in said suspension movement and a point
which is stationary relative to the crop harvesting machine as the header
moves
upwardly and downwardly relative to the crop harvesting machine and for
generating
a signal indicative of the sensed changes in said distance;
and an automatic header height control system which receives the
signal from the distance sensor and acts to raise and lower-the support
assembly in
response to the signal from the distance sensor so as to raise and lower the
support
assembly relative to the header and attempt to maintain said distance at a
required
set value.
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It is important that the adjustable links move in synchronism and this
can be achieved using a master and slave cylinder.
The suspension system is generally arranged such that upward
movement of the feeder house acts to reduce the separation between the header
and the adapter and downward movement of the feeder house acts to increase the
separation between the header and the adapter.
Preferably the adjustable link is a hydraulic cylinder. However an
electric actuator or other adjustable system operable from the cab could be
used.
Preferably the suspension system is adjustable so as to set a required
proportion of the weight of the header which is carried on the feeder house
relative
to a proportion of the weight of the header which is carried on the gauge
wheels.
Preferably the suspension system is arranged such that the proportion
of the weight which is carried on the feeder house is of the order of 90%.
Thus in the arrangement as described hereinafter, the gauge wheel
which can be adjusted from inside the cab is used in combination with an
Automatic
Header Height Control so that:
a) the main suspension is adjusted to carry approximately 90% of
the header weight
b) the header is dropped on the ground until the gauge wheels
contact the ground, and causes the header to "float" with respect to the main
carrier
frame;
CA 02665589 2010-11-25
c) The AHHC is set so that the combine feeder house stops
lowering when a pre-set amount of header to adapter separation (float) is
achieved.
This allows the header to move up and down smoothly to follow the
ground contour.
5 To change the cutting height, the cylinders attached to the gauge
wheels are operated. The AHHC then causes the main lift cylinders to react so
that
the pre-set float is maintained.
The arrangement described hereinafter may have one or more of the
following advantages:
10 It follows ground contour without having to carry excessive weight with
the gauge wheel;
The cutting height is adjustable from the combine cab through the
whole cutting range without changing the header angle;
With the AHHC, the weight carried by the gauge wheel is the same
through the cutting range;
With separation between the header and the adapter, the movement of
the combine from going over uneven terrain does not cause the header to move
up
and down, thus maintaining a more even cut height.
BRIEF DESCRIPTION OF THE DRAWINGS
One embodiment of the invention will now be described in conjunction
with the accompanying drawings in which:
Figure 1 is a schematic pan view of a combine harvester including a
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header assembly according to the present invention.
Figure 2 is a schematic cross sectional view along the lines 3-3 of
Figure 1.
Figure 3 is a schematic cross sectional view along the lines 2-2 of
Figure 1.
In the drawings like characters of reference indicate corresponding
parts in the different figures.
DETAILED DESCRIPTION
A combine harvester is shown schematically at 10 and includes ground
wheels 11, a main housing 12 containing the crop processing devices, a cab 13
for
the operator and a feeder house 14 for receiving the crop material and feeding
it into
the housing for processing. The details of combine harvesters are well known
to a
person skilled in this art so that no detail is necessary for an understanding
of this
invention.
The feeder house is mounted on the housing in a manner which allows
it to be raised and lowered to lift the header carried on the front of the
combine. For
example the feeder house includes cylinders 15 which raise and lower the front
end
16 of the feeder house.
The present invention is particularly directed to the construction of the
header assembly 20 for attachment to the feeder house of the combine
harvester.
The whole header assembly 20 includes a header 21 and an adapter
or connector 22 which connects the header to the feeder house so that the
feeder
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house acts as a support assembly for the header. The adapter 22 is provided to
control the feeding of material into the feeder house and to provide a lifting
force to
the header to carry it forwardly on the front of the feeder house.
The header is generally of a conventional construction well known to a
person skilled in this art and the major components include a cutter bar 23
for cutting
standing crop and a crop transport device defined by a pair of drapers 24 and
25 for
transporting the standing crop inwardly from ends of the header to a
collection
location 26 for feeding to the combine harvester.
The header includes two ground engaging gauge wheels 27 and 27A
on the header one on each side of the adapter 21. The number of wheels can be
increased in some cases so that double wheels are used or wheels on an axle
but in
generally the wheels act so support the header on each side of the support
from the
adapter.
Each gauge wheel is mounted on the header for up and down
adjustment movement of a position of the gauge wheel relative to the header to
control the height of the cutter bar of the header from the ground. Thus in
the
example shown the wheel is mounted on a pivot arm 28 pivotally mounted on the
header frame so that the arm projects rearwardly from the rear of the frame
with the
wheel at the rear end. The arm 28 is attached to the frame by an adjustable
link
which is typically a cylinder 29 operable by a control switch or manual
control 30
including a manual switch 31 arranged to be located in the cab 13 of the
combine
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harvester to adjust the position of the gauge wheel relative to the header to
a
required position so as to adjust the height of cut of the cutter bar from the
ground.
The gauge wheels 27 and 27A are fixed to the cylinders which are
fixed to the frame so that the wheels are mounted on the header such that,
when
adjusted to the required position, the gauge wheels are fixed relative to the
header
substantially without any suspension floating movement relative thereto- Thus
there
are no springs or suspension movements allowed and the wheel is rigid to the
frame.
The connection between the adapter and the header includes a
suspension system 30 with a center top link 32 and two side suspension arms 33
and 34 for carrying the header on the adapter. As is well known, the
suspension
arrangement allows side to side pivotal movement of the header relative to the
adapter as well as vertical floating movement of the header, that is upwardly
and
downwardly. Thus the suspension arms 33 and 34 include springs 33A and 34A
which have a spring force which can be adjusted to vary the lifting force
applied to
the header from the adapter.
Thus the suspension system is adjustable so as to set a required
proportion of the weight of the header which is carried on the feeder house
relative
to a proportion of the weight of the header which is carried on the gauge
wheels.
The springs of the suspension system are arranged such that a major
part of the weight of the header is carried on the feeder house and a smaller
part is
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carried on the gauge wheels and typically the proportion of the weight which
is
carried on the feeder house is of the order of 90%.
The suspension may be arranged such that upward movement of the
feeder house acts to increase a lifting force to the header and downward
movement
of the feeder house acts to decrease the lifting force to the header and/or
such that
upward movement of the feeder house acts to reduce the separation between the
header and the adapter and downward movement of the feeder house acts to
increase the separation between the header and the adapter, although these may
not occur depending on the mechanical arrangement or may not occur in all
parts of
the range of movement.
A bottom stop 38 is provided which is arranged to limit downward
movement of the header relative to the adapter. A distance sensor 39 is
provided
for sensing a distance of a point on the header which moves with the header in
suspension movement relative to the bottom stop 38, which is stationary
relative to
the harvesting machine. The distance sensor therefore generates a signal
indicative
of the sensed changes in said distance.
An automatic header height control system 40 is provided which is
arranged to raise and lower the feeder house in response to the signal from
the
sensor 39 so as to attempt to maintain the sensed distance at a required set
value.
The set value is selected so that the header is free to float between the
bottom stop
and an upper limit of movement both upwardly and downwardly to an extent to
accommodate changes in ground height. Thus the distance of the header from the
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ground is controlled by the gauge wheels and the weight of the header is
primarily
carried on the suspension of the feeder house. In the event that the set float
distance from the bottom stop decreases because the header has moved
downwardly relative to the feeder house, the lift cylinders 15 and 16 are
operated by
5 the automatic height control to lower the feeder house. In the event that
the set float
distance from the bottom stop increases because the header has moved upwardly
relative to the feeder house, the lift cylinders 15 and 16 are operated by the
automatic height control to raise the feeder house. The automatic header
height
control system is known to a person skilled in the art so that further details
of the
10 electronics necessary to effect the necessary controls is not required.
In operation, the header is dropped on the ground until the gauge
wheels contact the ground, and causes the header to "float" with respect to
the main
carrier frame. The AHHC is set so that the combine feeder house stops lowering
when the pre-set amount of header to adapter separation (float) is achieved.
This
15 allows the header to move up and down smoothly to follow the ground
contour. To
change the cutting height, the cylinders attached to the gauge wheels are
operated.
The AHHC then causes the main lift cylinders to react so that the pre-set
float is
maintained.
Since various modifications can be made in my invention as herein
above described, and many apparently widely different embodiments of same made
within the spirit and scope of the claims without department from such spirit
and
scope, it is intended that all matter contained in the accompanying
specification shall
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be interpreted as illustrative only and not in a limiting sense.
