Note: Descriptions are shown in the official language in which they were submitted.
26927-~3
The invention relates to a harvesting machi.ne provided with means
for the automatic elevation of the reel assembly when the feeding
apron is pivoted upwardly.
There are several demands made on the cutting header o~ a
harvesting machine. The first demand i5 that the crop be cut at
the desired height and be delivered as desired for further
treatment in the harvester. Therefore, the cutting header musk be
adjustable in accordance with often very varled harvesting
conditions or other specific demands. As an example may be
mentioned the demands made on the header of a whole crop
harvester, which include a very low stubble height. Prior art
often includes adjustable skids in combination with a spring
balancing system to make the header follow the ground contour
closely. In this case it is very important that the header is
well balanced, in other words the weight of the header must not
exceed the carrying abili~y of the skids in case the skids run
into an elevation. Otherwise the header easily digs into the
ground, which implies a great risk for extensive damage. In other
words, the header must be floating. It has been difficult to
unite these demands according to prior art. This is especially
true for very large and heavy cutter headers, with a great mass to
be accelerated and hence a low mobility.
Prior art also includes the use of mobile headers in combination
with sensing runners or other sensing elements underneath the
cutter-bar, which detect unevenness of the ground and feed
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26927-~3
lmpulses to the hydraulic cylinders of the integrated cutting
header. These known systems al50 include hydraulic balancing.
The purpose i~ to control the set stubble helght automatically.
The existing systems have not, however, solved the above problem,
and have in practice exhibited certain other drawbacks, such as a
risk of having the reel run into the cutter-bar when working at a
low height if the header is raised quickly as a result of the
detectors sensing some elevation of the ground underneath the
cutter-bar.
SU~MARY OF THE INVENTION
The invention provides apparatus for a harvestiny machine,
comprisingS a cutter bar; a reel assembly, including a reel;
a rear table comprising a feeding auger and a feeding elevator,
said rear table having a front and a rear and being pivotable to
said harvesting machine about a first horizontal axis of rotation;
a pair of reel carrying arms pivotally mounted about an axis of
rotation on said rear table for carrying said reel; a movable
feeding apron mounted in front of said rear table, said apron
having sides; a cutter bar provlded at a leading end of æaid
movable feeding apron; a pair of levers hingedly mounted on said
rear table about a second horizontal axis of rotation, said levers
having front arms and rear arms, said sides of said feeding apron
being connected to said front arms; first hydraulic means mounted
¦ relative to said machine for pivotally moving said rear table
about said first horizontal axis; second hydraulic means for
supporting said reel assembly and causing pivotal movement of said
pair of reel carrying arms, said second hydraulic means extending
2 ~
26921 43
between said pair of reel carrylng arms and a mounting point on
said movable feediny apron; third hydraulic means connected to
said rear arms of said levers for counter-balancing said feeding
apron and said reel assembly supported by said feeding apron about
said second axis of rotation; and ground following means connected
under said movable feeding apron for causing said feeding apron to
follow a ground contour when said machine is aclvanced while at the
same time raising or lowering said reel via said pair of reel
carrying arms, thereby avoiding co].lisions between said reel and
said cu-tter bar when said cutter bar is worlcing in a lower
position and said feediny apron is raised by said ground following
means due to elevation of said ground contour.
The header preferably includes a reel assembly with hydraulically
extendible arms, hydraulically extendible supporting arms which
stand on the mobile feeding apron providing for the reel to be
raised concurrently with the mobile feeding apron, should the
cutter-
2a
'
ga~ ~
bar run in~o some obstacle, and -thereby preventing the reel frorn
running into -the cutter-bar, when the reel is operating in its
lowermost position over the cutter-bar.
Further characteristics, objects, and advantages of the invention will
become apparent from the appended claims and the following description
of some preferred embodiments.
BRIEF DESCRIPTION OF DRAWINGS
In~the following description of preferred embodiments, reference will
be made to the attachsd drawings, wherein
Fig. 1 is a partly schematic sectional side elevation of a first
preferred embodiment of the header according to the
invention, the plane of the section being parallel to the
crop feeding direction;
Fig. 2 is a side elevation showing the cutter-bar of the header in
greater detail;
Fig. 3 is a circuit diagram of the regulating system of the header;
and
Fig. 4 shows a second embodiment of the header according to the
invention.
DESC~IPTION OF PREFERRED EMBODIMENTS
The header shown in Fig. 1 comprises four major parts, a stationary
table 1, a mobile feeding apron 2, a cutter assembly 3, and a reel
assembly 40
The stationary table 1 according to the art comprises a feeding auger
5 and is integrated with an elevator house 6, which comprises an
elevator (not shown~ transporting the crop into the harvesterO The
harvester is symbolically designated 7. The stationary table 1 pivots
about an axis 8 in the harvester and is turned by a pair of hydraulic
g
cylinders 9 -to be set in a chosen position. This set position is
characterized by the distance H between the ground and a horizontal
first axis 10.
The feeding apron 2 consists of a number of inter-connected sections.
Each section is provided with an endless feed belt 11, which is driven
in the direction of the arrow 12 by a drive pulley 13, powered by a
hydraulic motor (not shown). A front pulley is designated 14. The belt
11 is tensioned by means of a pair of gas springs 15. The belt 11
fbeds the material from the cutter assembly 3 to the stationary table
1, from where it is transported by the auger 5 and the elevator. The
gables of the described feeding apron 2 constitute the front arms 16
of a pair oP two-armed levers 18. The rear arms of the two levers have
been designated 17. In this mannerl the feeding apron 2 is hin8ed via
the gables/lever arms 18 to the stationary table 1, so that the lever
arms 18 and hence the apron 2 may pivot about said first turning axis
10, which has been set by the operator at a certain working position,
stationary in relation to the harvester 7.
On the underside of the feeding apron 2, across its entire breadth,
there are a number of wheels 24 distributed before and behind a
support 21. The hubs of the wheels are stiffly attached to the support
so as to avoid a bogie truck effect in the assembly. The wheels 24 can
be replaced by skids. At each end of the suppork 21 an internally
threaded sleeve 26 extends vertically upwards. In each of the sleeves
26 there is a screw 25 which may be turned by means of a handle 27.
Each of the sleeves 26 is attached to the gable of the feeding apron
2, specifically to the front lever arm 16, via a hinge 28. At the top
of the sleeve 26 there is a second hinge 29, which is the turni.ng
point of a tie rod 30. The second turning point of the tie rod 30 is
vertically above the said first turning axis 10. The screw 25 in the
threaded sleeve 26 is stiffly attached to the beam 21. The described
arrangement provides for the wheels 24 to remain in horizontal plane,
contrary to the situation with a bogie type assembly, and the sleeve
26 with the st:rew 25 inside it will always remain vertical. By turning
the screw 25 in the sleeve 26 at both sides of the header the feeding
g~9
apron 2 and hence the cutter assembly 3 may be raised or lowered with
respect to the ground.
The reel assembly 4 comprises a pair of extension cylinders 40. At the
outer end of the piston rod 41 on each of the extension cylinders 40
the reel 42 is mounted according to ~)rior art. The extension cylinders
40 - one on each side of the header -- are mounted on an arm 43, which
is journalled about the same first t~lrning axis 10 as the feeding
apron 2 or, as an alternative, about an other turning axis on the
kable 1. Each of the extension cylinders 40 i3 supported by a
hydraulic cylinder 44 which raises and lowers the extension cylinder
40 and consequently the reel 42. The cylinder 44 is hinged to the
gable of the feeding apron 2 by a hinge 45 at its bottom endl in other
words at the front arm 16 of the two-armed lever 18, and the piston
rod of the cylinder 44 is connected to an extension cylinder through a
hinge 47.
The apron 2 with its sides or gables 18 as well as the reel assembly 4
including the reel 42 which is supported on the apron 2 are counter-
balanced about the turning axis 10 by means of two hydraulic cylinders
20 and a gas accumulator 50 integrated in the hydraulic system. Thepiston rods of the hydraulic cylinders 20 are attached to the rear
ends of the rear lever arms 17 of the levers 18.
The cutter assembly 3 comprises, according to prior art, a knife 33
and a drive unit 34. From pre-determined set positions, as determined
by an adjustable stop 23 on the mobile feeding apron, the cutter
assembly 3, see Fig. 2, may be turned upwards, i.e. clockwise as
depicted in Figs. 1 and 2, about a hori7ontal second axis 35, which is
the turning axis of a two-armed lever. By moving the stop 23, the
cutting angle, i.e. the angle of,inclination of the ~nife 33 to the
standing crop may be changed. The front arm of the lever carries the
cutter assembly proper, comprising the kni~e 33 and the drive unit 34,
while the second, rear arm consists of a bracket-like horn 36, resting
against the adjustable stop. At the extreme end of the horn 36 there
is also a gas spring 37, which balances the weight of the cutter
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assembly 3. A micro-switch has been designated 3~. Should the cutter
assembly 3 run into the ground or into some obstacle, the assembly is
turned upwards about the second axis 35. If it turns more than a
pre-determined angle, the micro-switch 38 is activated, which in turn
disconnects a circuit in the regulating system, causing the hydraulic
cylinders 20 to lift the feeding apron 2.
Referring now to Fig. 3, the regulating system functions as follows.
For the purpose of turning the lever 18 about said first turning axis
lO,`see Fig. 1, two hydraulic cylinclers 20 are provided. In Fig. 3,
these have been designated 20A and 20B. The first cylinder 20A is a
master cylinder and the second 20B is a slave cylinder. The regulating
system comprises the following units: a gas accumulator 50, an
adjustable counter-pressure valve 51, with a built-in check valve 52,
a hydraulic four-way/three position directional valve 53, a first
electro-pneumatic three-way/two position directional valve 54, a
second electro-pneumatic three-way/two position directional valve 55,
a toggle switch 56, a cut-off valve 60, and the micro-switch 38, see
Fig. 2. Further, the hydraulic circuit, which is connected to the
hydraulic system of the harvester has been designated 57, a pneumatic
circuit has been designated 58, and an electric maneouvering circuit
has been designated 59.
When the machine is in operation, there is a balanced h~draulic
pressure in the accumulator 50, and this pressure is transmitted to
the slave cylinder 20B via the master cylinder 20A. The pressure is
adjusted so that the wheels 24 of the feeding apron 2 rest on the
ground with a slight pressure. In other words, the hydraulic cylinders
20A and 20B keep the feeding apron 2 balanced against the ground with
a pre-determined hydraulic pressure via the valve 51. Unevenness of
the ground, being detected by the wheels 24 and via the sleeve 26, the
shaft 28 and the lever arm 16 causing the lever 18 to turn about the
axis 10, thus affecting the cylinders 20A and 20B, is absorbed by the
spring action o~ the accumulator 50. The valve 53 is put in working
position, position II, by the toggle switch 56. The instruction to the
valve 53 to assume workin~ position is passed on from the toggle
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switch 56 by the firs-t electro-pneumatic valve 54. The operating
current to the first electro-pneumatic valve 54 is supplied via the
toggle switch 56 from the micro-swi-tch 38.
Should the cutter assembly 3 run into some mechanical obstruction and
be forced upwards a certain angle about the second axis 35, the
micro-switch 3~3 will disconnect the first electro-pneumatic valve 54,
even if the toggle switch 56 is in working position. Instead, current
will flow to the second electro-pneumatic switch 55, which will give
an up-instruction to the valve 53, position I. This will cause the
cut-off valve 60 to lock-in the preosure in the accumulator 50 so as
to give preference for the hydraulic oil to flow from valve 53 to the
cylinders 20A, 20B, so that the cylinders 20A and 20B immediately lift
the entire feeding apron 2 and hence also the reel assembly 4 by
pressing the rear lever arms 17 of the lever 13 down. Then a hydraulic
pressure is built up in the accumulator 50, via the valve 51 and the
built~in check valve 52. After a certain period of time, determined by
the slowness of the gas spring 37, the cutter assembly 3 will sink
back down until the horns 36 engage the stop 23 and the micro-switch
38 is closed again. As soon as the micro-switch 38 resumes its closed
normal position, the feeding apron 2 falls down until the wheels 24
rest on the ground. It is to be appreciated, that the reel assembly 4
is moved along with all these movements, since the extension cylinders
~0 are supported by the feeding apron 2. The effect is that there is
no risk of the reel 42 running into the cutter-bar 3, as the feeding
apron 2 is raised together with the cutter assembly 3, so that the
"floating" wheels 24 leave the ground, when the cutter assembly 3 runs
into some obstruction.
When in transport position, it is desirable that the feeding apron 2
with the cutter assembly 3, the wheels 24, and the reel assembly 4 are
temporarily lifted to a higher position. The operator can accomplish
this by feeding an up-instruction to the hydraulic cylinders 20A and
20B via the toggle switch 56, up position, which makes the pneumato-
hydraulic valve 53 give an up-impulse, position I, until the operator
lets go of the toggle switch 56~ The valve 53 then stops in zero
~26~ 9
position, locking the entire system in the up position. To resume
working position, the operator puts the toggle switch 56 into working
position, thus causing the feeding apron 2 to sink to an operating
position, determined by the setting of the wheels 24 and by the
pre-determined hydraulic pressure in the cylinders 20A and 20B,
balancing the feeding apron 2 and the reel assembly 4.
In the embodiment according to Fig. 4, details which have been
modified or displaced in comparison to the embodiment of Fig. 1 have
been indicated by a prime. Thus, there are hydraulic cylinders 20',
arranged below the stationary table 1 to turn the mobile feeding apron
2'. The wheels have been replaced by skids 24'. The rear lever arm is
shorter and is designated 18'. In this case the extension arm 43' is
hinged to the stationary table 1 by a hinge 46'. The lifting cylinder
44', the piston rod of which is connected to the extension cylinder
40' through a hinge 47', is pivotally connected at its bottom end to
the mobile feeding apron 2' by a hinge 45'. In this case also the reel
assembly 42 is raised together with the mobile feeding apron 2', if
the cutter assembly 3 runs into some obstruction, or if the feeding
apron 2' is raised by the skids 24', which follow the ground, and the
balanced hydraulic system, the reel 42 thus in both cases being
prevented from running into the cutter a~sembly 3, when the reel 42 is
working in its lowermost position. The rest of the construction i8
unchanged.
