Note: Descriptions are shown in the official language in which they were submitted.
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HEIGHT SENSOR ARRANGEMENT
FOR AGRICULTURAL APPLICATIONS
FIELD OF THE INVENTION
This invention relates generally to a sensor for detecting the height above
the soil of a
moving vehicle such as a harvesting machine, and is particularly directed to a
ground height
sensor having a curved ground-engaging arm comprised entirely of a high
strength, lightweight,
flexible and resilient elastomeric material capable of undergoing large
deformation upon impact
with obstructions and irregularities in the soil and assuming its original
shape and configuration.
BACKGROUND OF THE INVENTION
A common approach to crop harvesting involves the use of a combine having a
header
on its forward portion for engaging and removing the crop from a field. The
header is
maintained a designated height above the soil as determined by the type of
crop and various
operating conditions. Operating with the header too high will result in
failure to harvest all of the
crop, while operating too close to the soil increases the possibility of
damage to the header by
impact with rocks and other obstructions in the soil. With the use of longer
headers spanning
wider tracts, the possibility of impact of the header with the soil and
consequent damage to the
header and/or combine has correspondingly increased.
Various types of height sensors are used to maintain the harvesting machine a
designated
height above the soil for optimum crop recovery. Most current height sensors
employ a ground-
engaging arm suspended from the header and extending rearwardly relative ~to
the direction of
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travel. A cutter assembly is located in a bottom portion of the header housing
forward of the
height sensor arm. Thus, the sensor arm provides information regarding
vertical separation
between the cutter assembly and the soil with respect to soil the cutter
assembly has already
passed over. The inability to sense and provide information regarding terrain
in front of the
header limits the accuracy of the height control signals provided by the
height sensor. Moreover,
as the header gets closer to the ground, current sensor arms engage the ground
even further aft of
the cutter assembly thus increasing the separation between the position of the
cutter assembly and
the location of the soil the height of which is actually being detected.
The height sensor is typically includes a thin rod extending rearwardly and
engaging the
soil. These sensor arms are subjected to large forces. For example, a
downwardly force is
applied to the sensor arm to ensure that its distal end engages the soil. This
downward force is of
sufficient magnitude to allow the arm to penetrate plant residue in order to
contact the soil. In
addition, crop rows are frequently curvilinear to accommodate terrain contour.
Harvesting
curvilinear crop rows results in the application of large lateral forces on
the sensor arm. The
capability of combines, which incorporate rear steering, to rapidly turn and
change direction
increases the likelihood of sensor arm damage caused by the application of
large lateral forces.
In addition, field terracing wherein upraised strips of soil or elongated
shallow depressions, or
ditches, in the soil are foamed in a spaced manner over a field are
increasingly used to reduce
erosion. Traversing these upraised strips of soil or spaced depressions also
subjects the height
sensor arm to large forces while placing greater demands on sensing and
reacting to changes in
soil elevation to avoid damage to harvesting machinery. Also, in an attempt to
maximize crop
recovery, harvesting headers are increasingly being employed at lower heights
above the soil
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with increased force being applied to the height sensor arm. All of these
factors tend to increase
the likelihood of damage to the height control sensor resulting in harvester
down time and
production losses.
Header height control sensors are generally not designed with the
configuration of
existing headers as a primary consideration. Thus, the typical header height
sensor is not adapted
for retrofitting on an existing header without header modification. For
example, one current soil
height sensor employs a pair of pivotally connected curved arms mounted to a
lower portion of
the header housing. In order to accommodate this mufti-section height sensor
arm, the lower
surface of the header housing is provided with a recessed portion to receive
the arm sections for
storage and protection of the arms from damage when not in use. Not all
harvester heads are
provided with these height sensor arm storage recesses, thus, limiting the use
of this type of
sensor arm to headers having these recesses.
The present invention addresses the aforementioned limitations of the prior
art by
providing a height sensor arrangement particularly adapted for use in
agricultural applications
such as on a harvester, which provides an increasingly early warning of
upraised soil about to be
traversed by the harvester as its height above the soil is reduced. The height
sensor includes a
curved ground-engaging arm comprised entirely of a high strength, lightweight,
flexible and
resilient elastomeric material, such as thermoplastic polyurethane, capable of
withstanding very
large deformation forces without failing and assuming its original shape and
configuration for
continued reliable height sensing performance.
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OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a sensor arm
for a height
detector such as used in agricultural equipment components which is reliable,
lightweight and
highly resistant to various extreme environmental conditions as well as large
impact forces
arising from contact with the soil or obstructions in or on the soil.
It is another object of the present invention to provide a flexible arm for a
height sensor
for use in a combine header which is equally well adapted for use on a corn
header having a
recessed lower portion or on a header having a flat bottom skid plate.
Yet another object of the present invention is to provide a flexible arm for
use in an
agricultural height sensor for detecting the height of an agricultural
implement above the soil
which is capable of undergoing extreme bending, or deformation, in any
direction and then
assuming its original shape and configuration for continuing to provide
accurate implement
height information.
A further object of the present invention is to provide a curved height sensor
arm for use
in agricultural applications which is flexible, lightweight, resilient and
easily installed using
existing hardware on current harvesting headers for use with various crops and
has an extended
operating lifetime.
It is another object of the present invention to provide a height sensor for
an agricultural
implement traversing a field which increases the time between detection and
traversal of high
points in the soil by the crop engaging mechanism to facilitate implement
height adjustment and
the avoidance of impact with the soil.
Yet another object of the present invention is to provide a curved arm for a
ground height
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sensor which is of high strength and rugged, is flexible allowing the sensor
to be lowered to the
ground without damaging or breaking the arm, and engages the ground at a point
along its length
which moves forward in the direction of travel as the height sensor is lowered
to provide an
earlier warning of contact with upraised portions of the ground.
Still another object of the present invention is to provide a ground height
sensor
particularly adapted for agricultural applications, such as for use on a
harvester of the combine
header type, which can be easily mounted using conventional hardware at a
location forward of
or adjacent to the header's crop engaging mechanim.
A further object of the present invention is to provide a ground height sensor
for use in a
combine header which is easily installed on either end or on an inner portion
of a header
anywhere along its length without requiring modification of the header.
The present invention contemplates a sensor arm for measuring the height above
the soil
of an agricultural implement. The sensor arm comprises: an elongated, curved,
flexible member
formed entirely of an elastomeric material, wherein the elongated member is
bendable in any
1 S direction and capable of assuming its original shape and configuration
following bending; and a
mounting arrangement integrally formed in and disposed on one end of the
elongated member for
securely attaching the elongated member to the agricultural implement.
BRIEF DESCRIPTION OF THE DRAWINGS
The appended claims set forth those novel features which characterize the
invention.
However, the invention itself, as well as further objects and advantages
thereof, will best be
understood by reference to the following detailed description of a preferred
embodiment taken in
conjunction with the accompanying drawings, where like reference characters
identify like
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elements throughout the various figures, in which:
FIG. 1 is a partial front perspective view of a combine with an attached
header
incorporating a height sensor in accordance with the principles of the present
invention;
FIG. 2 is a partial perspective view of a lower portion of a combine header
illustrating the
mounting of a height sensor on a inner, lower portion of the header in
accordance with another
aspect of the present invention;
FIG. 3 is an exploded perspective view of one embodiment of a height sensor in
accordance with the present invention;
FIG. 4 is a perspective view illustrating details of the manner in which the
height control
sensor shown in FIG. 4 is attached to a combine header;
FIG. 5 is a partial perspective view shown partially in phantom illustrating
additional
details of the inventive height sensor;
FIGS. Sa and Sb are respectively perspective exploded and assembled views of
the height
sensor of FIG. 5 which incorporates an adjustable feature for varying the
downward, ground-
engaging force exerted on the sensor arm;
FIG. 6 is a partial perspective view of the embodiment of the height sensor
shown in FIG.
2 illustrating additional details of the manner in which it is mounted in the
header;
FIG. 7 is a perspective view of another embodiment of a height sensor in
accordance with
the principles of the present inventions;
FIGS. 8-12 are side elevation views of another embodiment of the height sensor
of the
present invention illustrating the manner in which the point of contact of the
sensor arm moves
forward along the length of the arm in the direction of travel as the
separation between the sensor
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and the soil is reduced;
FIGS. 13 is a perspective view of an improved height sensor arm in accordance
with the
present invention;
FIG. 14 is a front plan view of an agricultural header incorporating a pair of
improved
height sensor arms as shown in FIG. 13 illustrating the lateral deflection of
one of the sensor
arms upon impact with an obstruction in a field being traversed by the header;
FIG. 15 is a side perspective view of a combine header incorporating a height
sensor arm
in accordance with the present invention, where the header and sensor arm are
shown lowered to
the ground with the sensor arm assuming a generally linear configuration;
FIG. 16 is a side elevation view of a height sensor arm mounted to a
agricultural header in
accordance with the present invention, where the sensor arm is shown bent in
an upward
direction by a person grasping and raising the distal end of the sensor arm;
and
FIG. 17 is a partial perspective view of an agricultural header incorporating
a height
sensor arm in accordance with the present invention, where the header is shown
positioned on a
cart or trailer for header transport.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, there is shown a partial front perspective view of a
height sensor
arrangement 10 for use on a header 14 attached to a forward portion of a
combine 12. Combine
12 is conventional in design and operation and includes a chassis 30 disposed
on and supported
by four wheels, three of which are shown in the figure as elements 28a, 28b
and 28c. An
operator is positioned within a cabin disposed in the chassis. Also disposed
within the chassis
are a means for propulsion and various grain processing stages as well as a
storage bin for
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temporarily storing grain separated from plants ingested by the header. These
portions of
combine 12 are conventional and are not part of the present invention and are
thus not shown in
FIG. 1. Header 14 is also conventional in design and operation and includes a
crop gathering
unit 36 (partially shown in the figure) used in the harvesting of various
grains. Header 14 also
includes an elongated housing oriented generally at 90° relative to the
direction of travel of the
combine during harvesting.
Header 14 includes first and second end panels 14a and 14b. While only one
header
section is shown attached to a forward portion of combine 12 in FIG. 1, plural
header sections
attached by means of their respective end panels may be connected together and
mounted to a
forward portion of the combine to provide a wide harvesting path. Typically
attached to an upper
portion of header 14 is a crop engaging/gathering mechanism 36 for directing
the severed plant
residue into the combine for processing, with only a portion of this mechanism
shown in FiG. 1
because it does not form a part of the present invention. Shown respectively
attached to the first
and second header end panels 14a, 14b are first and second height sensor
arrangements 10 and 1 I
which are similar in operation and configuration as they embody the principles
of the present
invention. Extending lengthwise along the header 14 is an auger 20 also
oriented generally
transverse to the direction of travel of the combine 12. Auger 20 is
rotationally displaced by
means of a combination of a driven sprocket 24, a drive chain 22 and a drive
sprocket 26 which
is rotationally displaced by the combine's engine (not shown). Auger 20 is
provided with a pair
of complementary spiral sections which direct grain and plant residue taken in
by the header 14
toward the center of the header housing where it is directed aft into the
combine's feederhouse
(not shown) for processing within the combine. The bottom of the header 14 is
provided with a
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skid plate 18 extending the length of the header housing which is adapted to
engage and ride over
upraised portions ofuneven soil. Disposed adjacent a forward portion of the
skid plate 18 is a
cutterbar 16 which operates in a reciprocating manner to sever the upper
portion of plants
engaged by the header 14 as the combine 12 traverses a field. The thus severed
plants, with grain
attached thereto, are directed into the header's transverse auger 20 for
processing as described
above.
Because the first and second height sensor arrangements 10 and 11 are similar
in
operation and configuration, only the first height sensor arrangement will be
described in detail
for simplicity. The first height sensor arrangement 10 includes a curved,
flexible arm 34 having
a first proximal end and a second, opposed distal end. The height sensor
arrangement 10 further
includes a sensor mechanism 32 mounted to the header's first end panel 14a and
attached to the
proximal end of arm 34 for supporting the arm in a suspending manner. Sensor
mechanism 32 is
described in detail below. The distal end of arm 34 is attached to an aft
portion of header 14 by
means of a high strength connecting cable 38 which is preferably comprised of
steel. Connecting
1 ~ cable 38 prevents damage to the sensor arm 34 in the event the combine 12
is reversed in
direction.
Refernng to FIG. 2, there is shown another embodiment of a height sensor
arrangement
64 in accordance with the principles of the present invention. As in the
previously described
embodiment, height sensor arrangement 64 is attached to a header 50 having
first and second end
panels 52 and 54 as well as a crop gathering unit 58 attached to an upper
portion of the header.
A cutterbar assembly 56 is disposed in a lower, forward portion of the header
50 immediately
forward of a skid plate 62 forming the bottom portion of the header. In the
embodiment shown
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in FIG. 2, the height sensor arrangement 64 is attached to and suspended from
the header's skid
plate 62 by means of a mounting assembly 66 described in detail below. As in
the previously
described embodiment, the height sensor arrangement 64 includes a curved,
flexible arm 68 and
a connecting cable 69 coupling a distal end of the arm to an aft portion of
the header 50. A
hydraulic cylinder 60 is connected between the header SO and the combine for
raising and
lowering the header between a nonuse position and a use position and for
changing the height of
the header above the soil in accordance with output signals from the height
sensor arrangement
of the present invention.
Refernng to FIG. 3, there is shown an exploded perspective view of a height
sensor
arrangement 70 in accordance with another embodiment of the present invention.
FIG. 4 is a
perspective view of the height sensor arrangement 70 as installed on a header
crop divider 120,
while FIG. 5 is a perspective view of the height sensor arrangement in
assembled form. The
height sensor arrangement 70 shown in FIG. 3 is adapted for attachment to a
side panel of a
header as shown for the case of height sensor arrangements 10 and 11 in FIG.
1. Height sensor
arrangement 70 includes an elongated, curved flexible arm 72 having an outer
elastomeric sheath
73 shown in dotted line form in the figure and an inner high strength spring
steel shaft 74 which
is capable of flexing. Elastomeric sheath 73 protects arm 72 by absorbing high
energy impact
forces exerted on the arm such as when it engages an obstruction such as a
rock or root in the
field. Extending from a first end of the arm 72 and disposed within the outer
elastomeric sheath
73 and connected to the spring steel shaft 74 such as by weldments is a metal
reinforcing member
84 which provides the arm 72 with very high strength particularly, with
respect to lateral forces.
The combination of shaft 74 and reinforcing member 84 may also be formed by
bending the shaft
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back upon itself and positioning the curved bent-back portion in closely
spaced relation to the
proximal end of the shaft as in the embodiment shown in FIG. 3. Each of the
elastomeric sheath
73, shaft 74 and reinforcing member 84 is provided with the same radius of
curvature along those
portions of its respective length where it is in contact with one or more of
the other two
members, and none of these shaft members has a constant, fixed radius along
its entire length.
Each shaft member will assume its original curvature following removal of a
force which
changes its curvature. Arm 72 is flexible and has a curvilinear shape as shown
in the figure for
purposes which are discussed in detail below. One end of the spring steel
shaft 74 is provided
with an aperture 74a for installing the arm in the height sensor arrangement
70. A first proximal
end of ann 72 is provided with a first end aperture 72a, while second opposed
end of arm is
provided with a second distal end aperture 72b. The second end aperture 72b is
adapted for
receiving the combination of a threaded member 78a and a nut 78b for attaching
one end of the
connecting cable 76 to the second distal end of the arm 72. The first end
aperture 72a of the arm
72 is adapted to receive the combination of an elastomeric bushing 80 and an
insert member 82.
The insert member 82 is inserted within the elastomeric bushing 80 and
includes an aperture
extending therethrough. The aperture in the insert member 82 is adapted to
receive a threaded
member 87 which is also inserted through the aperture 74a in the end of the
spring steel shaft 74
for attaching the proximal end of the arm 72 to a bracket 86. The proximal end
of arm 72 is
securely attached to bracket 86 by means of the combination of the threaded
member 87 and a
nut 88. Also attached to bracket 86 by means of first and second threaded
members 98a and 98b
is a rotation sensor 94. Rotation sensor 94 is electrically coupled to the
combination of a header
CA 02511418 2005-07-05
controller 114 and a controller interface 112 'by means of the combination of
an electrical
connector 96 and one or more electrical leads 97.
Bracket 86 includes a circular aperture through which is inserted a fixed
shaft 92. A first
end of the fixed shaft 92 is attached to the rotation sensor 94, while a
second opposed end of
rotating shaft is connected to a sensor dial 102. Fixed shaft 92 is inserted
in a cylindrically-
shaped rotating shaft retainer 90. Shaft retainer 90 is inserted in an
aperture 100a of a sensor
housing 100. Disposed within sensor housing 100 is a torsion spring 106, with
the torsion spring
disposed about and connected to the shaft retainer 90 as both of these
components are disposed
within the sensor housing 100. Shaft retainer 90 extends through the sensor
housing 100 and
thus extends through aperture 100a as well as through a second aligned
aperture in an opposing
face of the sensor housing which is not shown in the figure for simplicity. A
first combination of
a bushing 108 and retaining ring 109a and a second combination of a bushing
110 and retaining
ring 109b are disposed about the shaft retainer 90 in a spaced manner within
the sensor housing
100 to maintain the shaft retainer within the housing while allowing the shaft
retainer to freely
rotate within the sensor housing. Retaining ring 109a is adapted for
positioning within a first
circumferential slot 90a within the rotating shaft retainer 90, while
retaining ring 109b is adapted
for positioning in a second circumferential slot (not shown in FIG. 3 for
simplicity) for securely
coupling the shaft retainer to housing 100 while allowing the shaft retainer
to rotate. Also
attached to the sensor housing 100 by means of the combination of a bolt 104a
and a nut 104b is
the aforementioned sensor dial 102. Sensor dial 102 is in the form of a thin,
elongated pin-like
structure which is wrapped around bolt 104a and freely rotatable about the
bolt. One end of the
sensor dial 102 is inserted into a notched end portion 92a of fixed shaft 92.
In addition, one end
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of the torsion spring 106 is securely connected to the shaft retainer 90
within the sensor housing
100. By engaging the notched end portion 92a of the fixed shaft 92, sensor
dial 102 securely
maintains the fixed shaft in fixed position within the sensor housing 100 and
establishes a zero
elevation reference for the height sensor, which elevation reference point is
adjustable. The
elevation reference point may be easily changed by providing plural spaced
apertures within
housing 100, with each aperture adapted to receive the combination of bolt
104a and its
associated nut 104b for changing the position of sensor dial 102 and the
orientation at which it
engages the end 92a of the fixed shaft 92. Shaft retainer 90 is freely
rotatable on the fixed shaft
92 about which it is positioned. With the shaft retainer 90 attached to an end
of the torsion
spring 106, the torsion spring urges the shaft retainer to a given rotational
position within the
sensor housing 100. Rotational displacement of arm 72 which is attached to
bracket 86 causes a
corresponding rotational displacement of the combination of the shaft retainer
90. In the
arrangement shown in FIG. 3, an inner portion of rotation sensor 94 is
maintained fixed by the
fixed shaft 92, while the sensor housing is allowed to rotate with the
rotating shaft retainer 90 to
1 S provide an indication of the rotation of the sensor arm 72 about the axis
of the shaft retainer
within sensor housing 100. Rotation of shaft 90 is detected by the rotation
sensor 94 which
provides a corresponding signal via electrical connector 96 and leads) 97 to
the controller
interface 112 which, in turn, provides a signal to header controller 114.
Header controller 114 is
connected to the header for adjusting the height of the header in accordance
with the rotation of
sensor arm 72 as provided by the height sensor arrangement 70.
Referring to FIGS. Sa and 5b, there are respectively shown exploded and
assembled
perspective views illustrating additional details of the height sensor
arrangement 70 shown in
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FIGS. 3, 4 and 5. As shown in FIGS. Sa and Sb, torsion spring 106 is attached
to the shaft
retainer 90 by means of a threaded pin 89, such as a bolt or screw, inserted
through an inner
portion 106a of the spring and into a threaded aperture 90c in a lateral
surface of the shaft
retainer. The outer end 106b of the torsion spring 106 is attached to the
sensor housing 100 by
S means of a coupling bracket 95. Coupling bracket 95 is attached to an inner
surface of sensor
housing 100 by conventional means such as a threaded coupling pin which is not
shown in the
figure for simplicity. Coupling bracket 95 is in the general shape of the
letter "E" and includes
first and second spaced recesses 95a and 95b. Each of the first and second
spaced recesses 95a,
95b is adapted to receive and securely engage the outer end 106b of torsion
spring 106. Coupling
bracket 95 and the two recesses 95a and 95b disposed therein allow the outer
end 106b of the
torsion spring 106 to be positioned in accordance with the amount of tension
to be applied to the
torsion spring. For example, with torsion spring 106 applying a rotational
force to the sensor arm
72 about it pivot axis aligned with rotating shaft 92, this rotational force,
and thus the downward
force with which the distal end of the sensor arm 72 engages the ground or
plant material
disposed on the ground, may be adjusted, as desired. By positioning the outer
end 106b of
torsion spring 106 in the second, lower recess 95b within coupling bracket 95,
the torsion spring
may be maintained under increased tension for urging the distal end of the
sensor arm 72
downward with greater force. On the other hand, by positioning the outer end
106b of torsion
spring 106 within the first, upper recess 95a of coupling bracket 95, torsion
spring lfl6 will be
maintained under a reduced tension and will thus exert a reduced downward
force on the distal
end of sensor arm 72. In this manner, the force with which the distal end of
sensor arm 72
engages the ground or plant material disposed on the ground may be adjusted as
desired to permit
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the sensor arm to penetrate a range of thicknesses of plant material disposed
on the ground.
While the figures show the coupling bracket 95 as having only two adjustment
positions,
coupling bracket 95 may be sized and configured to include a large number of
tension adjustment
positions to permit the torsion spring 106 to apply a wide range of the ground-
engaging force to
sensor arm 72.
As shown in FIG. 4, a sensor guard, or shielding plate, 124 is disposed
adjacent the height
sensor arrangement 70. Shielding plate 124 is attached to the header crop
divider 120 by means
of one or more threaded mounting pins 126. Shielding plate 124 is preferably
comprised of a
high strength, impact resistant material such as metal or plastic and protects
the height sensor
arrangement 70 from damage caused by impact with plant matter/crop residue as
well as with
obstructions in the field such as rocks.
Refernng to FIG. 6, there is shown a partial perspective view of another
embodiment of a
height sensor arrangement 130 in accordance with the present invention. The
height sensor
arrangement 130 shown in FIG. 6 is adapted for attachment to the skid plate 62
of a header 50
adjacent the header's cutter bar 149 such as illustrated in FIG. 2. In the
embodiment shown in
FIG. 6, the height sensor arrangement 130 is attached to the header skid plate
62 adjacent to, and
extends through, an aperture 132a within the plate. The height sensor
arrangement 130 includes
a sensor housing 142 attached to an upper surface of the header skid plate 132
by means of plural
threaded connectors. Disposed within and extending through facing apertures in
opposed
surfaces of the sensor housing 142 is a shaft retainer 143. Shaft retainer 143
is freely rotatable
within the sensor housing 142 and is connected at one of its ends to a
rotating shaft 144 as in the
previously described embodiment. In the embodiment shown in FIG. 6, rotating
shaft 144 is
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disposed within and extends through a torsion spring 146. One end of the
torsion spring 146 is
securely attached to either sensor housing 142 or skid plate 132, while a
second end of the
torsion spring is connected to the rotating shaft 144. A rotation sensor is
also connected to the
rotating shaft 144, although this is not shown in the figure for simplicity.
Also attached to the
S rotating shaft 144 so as to rotate therewith is a coupling bracket 145.
Coupling bracket 145
includes a generally flat mounting plate 136 to which is attached one end of a
sensor arm 134 by
means of the combination of a threaded pin 138 and nut 140. A combination of
the coupling
bracket 145 and mounting plate 136 extends through the aperture 132a within
the header skid
plate 132. As sensor arm 134 is deflected and displaced upon impact with the
soil in the
direction of arrow 150, the combination of the rotating shaft 144, coupling
bracket 145 and
mounting plate 136 rotates about a generally horizontal axis passing through
the rotating shaft.
The rotation sensor (not shown) coupled to the rotating shaft 144 detects
rotation of the sensor
arm 134 and provides an appropriate signal for controlling the height of the
header above the
soil. A sensor guard 148 in the form of a generally flat, high strength plate
such as of steel or
1 ~ plastic is attached by conventional means such as weldments or threaded
connecting pins to a
lower surface of the header skid plate 132 for protecting the height sensor
arrangement 130 from
damage caused by impact with the soil.
Referring to FIG. 7, there is shown another embodiment of a height sensor
arrangement
152 in accordance with the principles of the present invention. As in the
previously described
embodiment, the height sensor arrangement 152 shown in FIG. 7 is adapted for
attachment to the
lower, leading edge or surface of a header skid plate 154 adjacent the
header's cutter bar 180. In
the arrangement of FIG. 7, the upper end of a sensor arm 166 is attached to a
coupling bracket
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164 by means of the combination of an elastomeric hushing 174, an insert
member 172, and a
threaded pin 168 and nut 170 combination. Coupling bracket 164 is also
attached to a cylindrical
shaft coupler 160 by conventional means such as weldments, which are not shown
in the figure
for simplicity. First and second ends of the shaft coupler 160 are securely
attached to a lower
S surface of the header skid plate 154 by means of first and second mounting
brackets 156a and
156b, respectively. Shaft coupler 160 is rotatably attached to each of the
first and second
mounting brackets 156a, 156b, allowing the combination of coupling bracket 164
and sensor arm
166 attached thereto to freely rotate with respect to the header. A first end
of the shaft coupler
160 is attached to a torsion bar 158, which is shown as having six sides,
while a second opposed
end of the shaft coupler is attached to a rotating shaft 162. The other end of
the torsion bar 158 is
fixedly attached to the header in a conventional manner such that the attached
end of the torsion
bar is not free to rotate about its longitudinal axis. The other end of the
rotating shaft 162 is
attached to a rotation sensor 176 which measures the extent of rotation of the
shaft and sensor
arm 166 attached thereto as in the previously described embodiments. Rotating
shaft 162 may be
1 S rigid or it may be in the form of a flexible steel cable to facilitate
mounting of the rotation sensor
176 on the header. Torsion bar 158 maintains the sensor arm 166 at a given
inclination relative
to the header and exerts a rotational force on the sensor arm which must be
overcome prior to
rotation of the sensor as it contacts the soil. The force applied to the
sensor arm 166 by the
torsion bar 158 maintains a distal end of sensor arm 166 in contact with the
soil. An elongated,
curvilinear shield 178 is shown in dotted line form mounted to a forward
portion of the header to
protect the height sensor arrangement from damage caused by impact with the
crop or with
obstructions in the field. Height sensor arrangement 152 incorporating the
rigid, elongated
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torsion bar 158 may also provide for varying the downward force applied to the
sensor arm 1~6
as in the previously described embodiment. For example, torsion bar 158 may be
in the form of a
six sided shaft as shown in FIG. 7 which is maintained in position by a
mounting bracket (not
shown) at least partially disposed about the torsion bar and attached to the
header skid plate 154
S by plural mounting pins (also not shown). Plural threaded apertures may be
provided along the
length of the mounting bracket, with each aperture adapted to receive a
threaded pin which
engages one of the lateral surfaces of the torsion bar 158. With the lower end
of the sensor arm
166 engaging the ground, torsion bar 158 may be rotationally displaced so that
the desired
amount of downward force is applied to the sensor arm. The rotational position
of the torsion bar
158 may then be locked in position by tightening the threaded pins engaging
lateral surfaces of
the torsion bar 158 and preventing it from rotating for maintaining the
desired downward force
on the sensor arm 166. Although this arrangement is not shown in the figures,
it could easily be
implemented by one skilled in the relevant arts.
Referring to FIGS. 8-12, the operation of the sensor arm 190 of the present
invention will
now be described. Sensor arm 192 includes first, second and third sections
192a, 192b and 192c.
The first and second sections 192a, 192b are securely connected together by
plural connecting
pins 206, while the second and third sections of the sensor arm 192 are
securely connected
together by means of second plural connecting pins 208. A lower distal end of
the sensor arm
192 is provided with a bulbous portion 204 for engaging the soil 210. Sensor
arm 192 further
includes a high strength plastic rod 200 and a metal reinforcing member 202 as
in the previously
described embodiments. Metal reinforcing member 202 is connected to and
extends from a
rotation sensor 194. The sensor arm's first section 192a is connected to the
metal reinforcing
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member by means of a threaded connecting pin 96. The high strength plastic rod
200 is also
connected to the metal reinforcing member 202 by conventional means and to the
three sections
of the sensor arm 192 by the first and second plural connecting pins 206 and
208 which draw
adjacent portions of the arm together with the plastic rod between them in a
clamping manner.
Sensor arm 190 is first provided with a predetermined curvature as shown in
the various figures.
1n FIG. 8, the height sensor arrangement 190 is shown in an elevated position,
where the
distance between the rotation sensor 194 (and the header to which it is
attached), is shown as h,.
At this height, the bulbous portion 204 of the sensor arm 192 engages the soil
210 a distance x,
aft of the rotation sensor 194, where the combine is moving in a direction
from right to left as
viewed in FIGS. 8-12. FIG. 9 is a side elevation view of the height sensor
arrangement 190 at a
medium height, where the distance between the rotation sensor 194 and the soil
210 is h2. At this
lower height, an intermediate portion of the sensor arm 192 engages the soil a
distance x2 aft of
the rotation sensor 194, where x2 < x~. FIG. 10 shows the height sensor
arrangement 190 at a
lower elevation relative to the soil 210, where the distance between the
rotation sensor 194 and
the soil is h3. In the lower position of FIG. 10, the curved sensor arm 192
engages the soil
adjacent the center of the sensor arm at a distance x3 aft of the rotation
sensor 194, where x3 < xz
< x,. FIG. 11 is a side elevation view of the height sensor arrangement 190 at
an even lower
position relative to the soil 210. At this height, the sensor arm 192 engages
the soil at a location
close to the proximal end of the arm and in closely spaced relation from the
rotation sensor 194.
At the reduced height of the rotation sensor 194 shown in FIG. 11, the point
of contact of the
sensor arm 192 with the soil is x4 aft of the rotation sensor, where x4 < x3 <
x2 < x,. From FIGS.
8-11, it can be seen that as the height of the rotation sensor 194 (and thus
the height of the
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header) is reduced, the point of contact of the sensor arm 192 moves forward
in the direction of
travel of the combine to provide an earlier warning of upraised portions of
the soil to facilitate
raising the header and avoiding contact with the soil and reducing the
possibility of damaging the
header.
FIG. 12 is a side elevation view of the height sensor arrangement 190, with
the rotation
sensor 194 in contact with the soil and the sensor arm in a substantially
linear configuration. The
header and height sensor arrangement would not be operated as shown in FIG.
12, but this figure
illustrates the high strength and flexibility of the sensor arm 192 which
allows for contact of a
lower portion of the header with the soil so as to position the sensor arm in
contact with the soil
along a substantial portion of its length without damaging or breaking the
sensor arm. In
addition, the substantially flat configuration assumed by the sensor arm 192
when in substantially
full contact with the soil without damage to the sensor arm eliminates the
requirement for a
recess in the lower surface of the header to receive the sensor arm when the
header is in contact
with the soil as in some current headers.
Refernng to FIG. 13, there is shown a perspective view of a height sensor arm
222 in
accordance with another aspect of the present invention. Height sensor arm 222
includes a
proximal mounting end 224, a distal ground-engaging end 228 and a curved shaft
portion
disposed between and formed integrally with the proximal and distal end
portions. Height sensor
arm 222 has a curved configuration and is concave in an upward direction when
installed on an
agricultural vehicle such as a harvesting machine. The proximal end 224 of the
arm includes first
and second mounting apertures 230a and 230b and a recessed portion 232.
Recessed portion 232
is adapted for mating engagement with a structure attached to or formed
integrally with a header
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(not shown in the figure of simplicity). The first and second mounting
apertures 230a, 230b are
each adapted to receive a respective nut and bolt combination for securely
attaching the height
sensor arm 222 to the header. The distal ground-engaging end 228 of the arm is
curvilinear in
shape and includes an aperture 236 extending therethrough. Extending from the
aperture 236 to
an outer edge of the height sensor arm 222 is a slot 234. Slot 234 is adapted
to receive a
connecting member (also not shown in the figure) for permitting the connecting
member to be
inserted into aperture 236 for connecting the distal ground-engaging end 228
of the arm to the
header. The connecting member, an example of which is shown in FIG. 1 as a
connecting cable
38, may be in the form of a rope or chain, preferably comprised of steel, or
it may be in the form
of high strength strapping such as of nylon. The connecting member prevents
damage to the
height sensor arm 222 in the event the header is reversed in direction. The
use of a cable, rope,
chain or strapping connected to the height sensor arm's distal end is
optional, as the strength,
resilience and flexibility of the sensor arm of the present invention has
essentially eliminated the
need for this type of sensor arm restraining member.
Height sensor arm 222 is comprised of a high strength, flexible material which
is highly
resilient and thus capable of assuming its original shape and configuration
after undergoing
substantial deformation or deflection. In a preferred embodiment, height
sensor arm 222 is
comprised of an elastomer having excellent tensile and tear properties, high
stiffness
characteristics, good resistance to fuels and oils, and inherent resistance to
hydrolysis and the
attack of fungi. More specifically, height sensor arm 222 is preferably
comprised of a polyether-
based thermoplastic polyurethane with a shore hardness of approximately 70D; a
specific gravity
of 1.18; Taber abrasion resistance of 75; and a Bayshore resilience of 50. A
specific example of
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this type of material is Texin 970U resin (formerly known as 970D). This
polyether-based
thermoplastic polyurethane is available from Bayer Polymers of Pittsburgh,
Pennsylvania.
Refernng to FIG. 14, there is shown a front view of an agricultural header 240
incorporating first and second sensor arms 256 and 258 in accordance with the
principles of the
present invention. Header 240 is mounted to the front of a combine, with only
wheels 242 and
244 of the combine shown in the figure for simplicity. Header 240 includes a
body portion
aligned generally transverse to the direction of travel of the combine.
Disposed on opposed ends
of the header's body portion are first and second header end plates 246a and
246b. Disposed on a
forward portion of the header 240 is a cutter bar 248 and a crop gathering
unit 250 disposed
above the cutter bar. In some headers, such as those used in the harvesting of
wheat, a generally
flat skid plate 252 is disposed below the cutter bar 248 and forms the bottom
of the header 240.
Disposed adjacent the cutter bar 248 and extending between the header's first
and second end
plates 246a, 246b is a cross member 254. Attached to the cross member 254
adjacent its opposed
ends are first and second mounting plates 260 and 262. Respectively attached
to the first and
1 S second mounting plates 260, 262 are first and second coupling brackets 264
and 266.
Respectively attached to the first and second coupling brackets 264, 266 are
the first and second
sensor arms 256 and 258. Conventional nut and bolt combinations are used for
attaching the first
and second mounting plates 260, 262 to the cross member 254, as well as for
securely attaching
the first and second coupling brackets 264, 266 to the first and second
mounting plates 260, 262,
respectively. As previously described, the first and second sensor arms 2~6,
258 respectively
include proximal mounting ends 256a and 258a disposed at the upper end of the
sensor arm. The
proximal mounting ends 256a, 258a of the first and second sensor arms 256, 258
are respectively
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attached to the first and second coupling brackets 264 and 266 by conventional
means such as
nut and bolt combinations. The above-described sensor arm mounting and
installation
arrangement is provided for illustration purposes, as the sensor arm of the
present invention may
be installed using various mounting arrangements. For example, the inventive
sensor arm may
be mounted using conventional connectors to a guard for the crop cutter bar
248 which is not
shown in the figures for simplicity. In addition, while the height sensor arm
of the present
invention is disclosed as mounted to opposed ends of the header, the inventive
height sensor arm,
or several such sensor arms, may be positioned virtually anywhere along the
length of the header.
As headers increase in length, more height sensor arms are being installed in
a spaced manner
along the length of the header.
As the header 240 and combine combination traverses the surface of the soil
270, the first
and second sensor arms 256 and 258 contact the soil, as well as any
obstructions in or on the soil.
For example, the second sensor arm 258 engages the soil, while the first
sensor arm 256 is shown
in the figure contacting a rock, or boulder, 268 on the soil 270. Impact of
the first sensor arm
256 with rock 268 will cause the sensor arm to bend rearwardly and also, in
most cases,
transversely relative to the direction of travel of the header 240. Transverse
deflection of the first
sensor arm 256 is shown in FIG. 14. While the first sensor arm 256 is shown
engaging a rock
268 in FIG. 14, various other obstructions are commonplace in the soil and
typically give rise to
rearward and transverse deflection of the sensor arm. In addition to rocks and
boulders, these
obstructions include roots, ruts, terraces, etc. The flexible and resilient
characteristics of the
sensor arm of the present invention allow it to be deflected transversely and
to immediately
assume its original shape and configuration once the obstruction is passed.
Thus, a sensor arm
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in accordance with the present invention is capable of providing accurate
height sensing
information immediately after being deflected in any direction by an
obstruction in or on the soil.
Current sensing arms comprised of, or incorporating, a high strength metal
such as steel, either in
the form of a straight or curved elongated arm, are not designed for lateral
bending and are thus
subject to permanent deformation or breakage upon impact with an obstruction
in the soil
causing lateral deflection of the sensor arm.
Refernng to FIG. 15, there is shown a side perspective view of a header 276
incorporating a height sensor arm 284 in accordance with the principles of the
present invention.
As in the previously described header, header 276 includes a crop gathering
unit 290 on a
forward portion of the header. Header 276 also includes a pair of end panels,
where one of the
end panels is shown as element 278 in FIG. 15. Attached to end panel 278 is a
sickle drive
mechanism 282 which drives the aforementioned cutter bar. Also attached to the
header end
panel 278 is a mounting bracket 286. Extending through the mounting bracket
286 is a rotating
shaft 292 to which is attached by conventional means a coupling bracket 288.
Height sensor arm
284 is attached to coupling bracket 288 by conventional means such as nut and
bolt
combinations. The combination of coupling bracket 288 and height sensor arm
284 causes
rotation of shaft 292 with deflection of the height sensor arm as it traverses
a field. Rotational
displacement of shaft 282 gives rise to signals representing the height of the
header 276 above
the surface of the soil.
As shown in FIG. 15, head 276 has been lowered so that it rests upon and
engages the soil
280. In this position, height sensor arm 284 has been fully deflected in a
counter-clockwise
direction about the axis of rotating shaft 292 as viewed in FIG. 15. When
fully deflected, height
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sensor arm 284 assumes a generally linear configuration as it engages and
rests upon the soil 280.
The flexibility of the height sensor arm 284 allows it to change its shape and
assume a generally
flattened configuration as shown in FIG. 15 while still being capable of
assuming its initial
curved configuration upon removal of the distorting force applied to the
height sensor arm. In
some header installations, the height sensor arm 284 may be located between
the header's end
panels and disposed forward of and below the generally flat skid plate located
on a lower portion
of the header. This is the case for height sensor arms 256 and 258 relative to
skid plate 252 as
previously described with respect to FIG. 14. When the sensor arm is
positioned as shown in
FIG. 14, lowering of the header to a position where its skid plate is closely
spaced from or
engages the soil will also force the height sensor arm into intimate contact
with the soil
substantially along its entire length such as shown in FIG. 15. With height
sensor arm 284
located beneath the header's skid plate, lowering of the header to a position
wherein it rests upon
and engages the soil causes the sensor arm to also engage the header's lower
skid plate. In the
case of prior height sensor arms comprised of or incorporating an elongated
steel member, this
results in permanent deformation or breakage of the height sensor arm.
However, the strength
and flexibility of the height sensor arm of the present invention allows it to
be positioned
between and in contact with the soil and the header's lower skid plate and to
assume a generally
linear configuration without breaking or damaging the height sensor arm which
will assume its
original curved shape and configuration when the header is elevated to a
position above the soil.
Referring to FIG. 16, there is shown another installation of a height sensor
arm 300 in
accordance with the present invention in a header incorporating an end panel
298. Height sensor
arm 300 includes a proximal mounting end 300a and a distal ground-engaging end
300b.
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Mounting hardware for attaching the height sensor arm 300 to a lower portion
of the header end
panel 298 includes first and second structural members 304 and 306 and a
sensor support
structure 302. The first and second structural members 304 and 306 are
attached to and
suspended from the header end panel 298 by various attachment brackets as is
conventional. The
arm's proximal mounting end 300a is attached to a coupling bracket 308 which,
in turn, is
attached to a mounting bracket 310. Conventional means such as nut and bolt
combinations are
used for attaching the height sensor arm 300 to coupling bracket 308 and for
affixing the
coupling bracket to mounting bracket 310. As in the previously described
embodiment, coupling
bracket 308 is attached to a rotating shaft which provides rotational
displacement signals to a
detector (not shown for simplicity) representing rotational displacement of
the height sensor arm
300 as it engages and traverses the soil. The flexibility and resilience of
height sensor arm 300
allows it to be bent in a direction opposite to its curvature into the
upwardly extended
configuration shown in FIG. 16 as it is grasped and pulled upwardly by a
person. The sensor
arm's resiliency allows it to assume its original configuration and shape
wherein it extends
downwardly and rearwardly from coupling bracket 308 and assumes an upwardly
concave
curvature when released from its upwardly bent configuration shown in FIG. 16.
The change in
configuration and shape that height sensor arm 300 undergoes by firmly
grasping and lifting the
arm's distal end 300b, as shown in FIG. 16, is not likely a change which the
arm would undergo
in an operating environment, but it is similar to deflection of the arm which
occurs when the
agricultural implement to which the arm is mounted is reversed in direction.
In this case, the
sensor arm engaging the soil is bent backward and undergoes considerable
deformation and
distortion. The height sensor arm 300 shown in FIG. 16 is undergoing even
greater deformation
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and distortion than that encountered by a sensor arm in an implement moving in
reverse and is
still capable of assuming its original shape and configuration to provide
reliable and accurate
implement height information when moving in a forward direction.
Referring to FIG. 17, there is shown a partial perspective view of a trailer
316 adapted for
supporting and transporting a header 318. As previously described, header 318
includes a cutter
bar 320 and a skid plate 330 extending rearwardly from the cutter bar. Skid
plate 330 forms a
lower portion of the header 318. Header 318 further includes a cross member
322 to which is
attached a mounting plate 324 by conventional means such as nut and bolt
combinations. A
coupling bracket 326 is attached to the mounting plate 324 and is further
connected to an upper
end portion of a height sensor arm 328 in accordance with the present
invention.
Header trailer 316 includes various structural members including first, second
and third
transverse structural members 332a, 332b and 332c. Header trailer 316 further
includes various
longitudinal structural members which are aligned along the direction of
travel of the trailer.
These latter structural members includes first, second, third and fourth
longitudinal structural
members 334x-334d. The various transverse and longitudinal structural members
are connected
together by weldments and/or other structural members, such as vertical
structural member 336
connecting the third transverse structural member 332c and the third
longitudinal structural
member 334c.
As shown in FIG. 17, the curved, flexible, resilient height sensor arm 328 of
the present
invention engages the third transverse structural member 332c as it is being
loaded onto the
header trailer 316. Contact between height sensor arm 328 and the third
transverse structural
member 332c causes substantial bending and deformation of the sensor arm.
Removal of header
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318 from trailer 316 may also cause substantial bending and deformation of
height sensor arms
attached to and suspended from the header if the arm catches on a portion of
the trailer. In the
case of prior height sensor arms comprised of or incorporating a high strength
steel member,
positioning the header on and removal of a header from its trailer can
frequently result in
permanent deformation or breakage of the header's height sensor arms. However,
the high
strength, flexibility and resilience of the height sensor arm of the present
invention allows it to
bend over virtually any deflection angle upon contact with the trailer when
positioning the header
on or removing the header from the trailer without either breakage or
permanent deformation of
the height sensor arm.
While particular embodiments of the present invention have been shown and
described, it
will be obvious to those skilled in the relevant arts that changes and
modifications may be made
without departing from the invention in its broader aspects. Therefore, the
aim in the appended
claims is to cover all such changes and modifications as fall within the true
spirit and scope of
the invention. The matter set forth in the foregoing description and
accompanying drawings is
offered by way of illustration only and not as a limitation. The actual scope
of the invention is
intended to be defined in the following claims when viewed in their proper
perspective based on
the prior art.
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