Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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DRAPER ARRANGMENT FOR A COMBINE HARVESTER PICK-UP
This invention relates to a draper arrangement of a crop pick-up for a
harvesting machine and particularly a combine harvester for picking up a swath
of
harvested crop for feeding into a feeder house of the combine harvester.
BACKGROUND OF THE INVENTION
Typical drapers of pick-ups for a combine include a plurality of side by
side joined endless belts wrapped around front and rear parallel spaced
rollers
where one of the front and rear rollers is a driven roller to drive the belts
to carry
crop rearwardly from the front roller to the rear roller.
The draper belt arrangements of a combine pickup available on the
market typically have tracking and slippage issues in that the belt
arrangement must
be guided to properly track around the front and rear rollers and must be
driven in a
manner which limits slippage of the belts on the driven roller. Tracking of
drapers
currently is done by guiding disks on the exterior surface of the rollers or
in some
cases by adjusting the position and/or tension of the outer roller supports.
In such
pick-ups the twisting of the deck as it moves across the ground combined with
the
short distance between the front and rear rollers causes the draper to wander
laterally. At the same time there is a tendency for the belts to slip relative
to the
driven roller so that the feed rate changes in an unacceptable manner.
The slippage issue is determined to be a result of roller deflection due
to the draper tension causing the middle draper belts to have less tension
than the
outer belts. Solutions to the deflection of these long rollers include having
roller
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diameter which is larger in the center with respect to outer ends, changing
one long
roller into two shorter rollers or pusher devices to limit deflection of
roller. All these
solutions not only are not cost effective but have not adequately functionally
performed.
In US patent 6,131,728 (Rizhanovsky) issued October 17, 2000 to
Precision Metal shows an end to end connection for the ends of a draper
suitable to
be used on a pick-up of this type.
In US patent 7,344,020 (Grywacheski) issued March 18, 2008 to Deere
shows another connection for a draper suitable to be used on a pick-up of this
type.
Neither of these patents addresses the issues of slippage or guidance.
SUMMARY OF THE INVENTION
It is one object of the invention to provide an improved draper
arrangement for a crop pick-up.
According to one aspect of the invention there is provided a crop pick-
up for a harvesting machine comprising:
a front roller;
a rear roller parallel to and spaced from the front roller;
one of the front and rear rollers being a driven roller for driven rotation
around its axis;
an endless draper belt assembly wrapped around the front and rear
rollers so that rotation of the driven roller acts to drive the belt assembly
to carry crop
rearwardly from the front roller to the rear roller;
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the endless draper belt assembly comprising a plurality of endless
belts arranged side by side across the front and rear rollers so as to define
two side
belts and at least one intermediate belt;
each belt comprising a belt length wrapped around the rollers and
connected at ends of the belt length to form the respective endless belt;
each endless belt being connected to its respective next adjacent
endless belts at spaced positions along its length so as to connect the
endless belts
for common movement around the rollers;
each of the front and rear rollers having a peripherally extending guide
groove therein;
and a plurality of guide elements mounted in a row along an inside
surface of one of the endless belts for tracking in the guide grooves in the
front and
rear rollers;
the guide elements being separate each from the next so as to be
fastened at spaced positions along said one of the endless belts;
the guide elements being fastened each by a respective separate
fastener passing through said one of the endless belts.
Preferably the groove is formed in the drive roller which is typically the
larger rear roller.
Preferably the groove has tapered side walls with the taper being in the
range 10 to 20 degrees and preferably of the order of 15 degrees.
Preferably the guide elements are wider in the transverse direction
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than they are long in the longitudinal direction and are typically less than
20 mm in
length and preferably of the order of 16 mm to enable the belt to conform to
the roller
diameter and are typically greater than 30 mm in width and preferably of the
order of
36 mm.
Preferably the guide elements are fastened by a single bolt through the
guide element and through the belt for connection to a nut on the outer face
of the
draper belt. Preferably the bolt has a head which is recessed into an interior
of the
guide element.
Preferably the guide elements have at least one and preferably two
prong protrusions at a side of the bolt that engage or bite into the draper to
prevent
rotation of the guide element on the draper.
Typically the belt assembly carries a plurality of spaced finger
members on an exterior surface thereof and the bolt connecting the guide
elements
to the belt assembly also is used to attach a respective one of the finger
members.
As there generally needs to be more guide elements than fingers, the row of
guide
elements includes at least one additional guide element between each finger
member and the next.
Preferably the guide elements are formed of a plastics material so as
to provide a suitable bearing surface relative to the metal rollers.
Preferably the guide elements have a depth into the groove of at least
10 mm and preferably of the order of 14 mm to not only contain the guide
element
inside the roller groove but also to sufficient surface area on sides of the
guide
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element relative to the groove to achieve acceptable wear.
Preferably the endless belts are connected side by side by transverse
connecting bars to essentially make the belt assembly functionally rotate
around the
rollers as a one piece assembly. Thus the endless belts can be connected by a
5
splicing connector connecting the ends of the belt lengths and spanning across
from
one belt to the next, with the splicing connector preferably extending from a
mid
span of one belt to a mid span of the next. Thus the endless belts can be
connected
additionally by a series of plates at longitudinally spaced positions along
the belts
and spanning the edges of the belts.
In order to even out tensiOn in the belts while accommodating some
bowing of the rollers, at least one intermediate belt is connected such that
the belt
length thereof is shorter than the belt length of the two side belts.
Typically there are
four belts and the two intermediate belts are shorter than the side belts.
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 an isometric view of one embodiment of a pick-up
according to the present invention with the support and drive assemblies for
the
rollers carrying the draper belts being omitted for convenience of
illustration.
Figure 2 is a similar isometric view of an intermediate part only of the
embodiment of Figure 1.
Figure 3 is a similar isometric view of an end part only of the
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embodiment of Figure 1.
Figure 4 is an end elevational view of the embodiment of Figure 1.
Figure 5 is a top plan view of the intermediate part only of the
embodiment of Figure 1.
Figure 6 is a top plan view of the intermediate part only of the
embodiment of Figure 1.
Figure 7 is a cross sectional view along the lines 7-7 of Figure 4.
In the drawings like characters of reference indicate corresponding
parts in the different figures.
DETAILED DESCRIPTION
The crop pick-up 10 of the embodiment shown in the drawings
includes a front roller 11 and a rear driven roller 12 parallel to and spaced
from the
front roller 11.
An endless draper belt assembly 13 is wrapped around the front roller
11 and rear roller 12 so that rotation of the driven roller in the direction
D1 acts to
drive the belt assembly in the upward rear direction D2 to carry crop
rearwardly from
the front roller to the rear roller. The endless draper belt assembly is
formed by four
belts 13A, 13B, 13C and 13D arranged side by side across the rollers so as to
define
two side belts 13A, 13D and two intermediate belts 13B, 13C.
As shown in Figure 4, each belt is formed by a belt length 14 with ends
14A and 14B wrapped around the rollers and connected at the ends of the belt
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length by a connector strip 15 attached by a row of bolts 16 to form the
respective
endless belt.
Each endless belt is connected to its respective next adjacent endless
belts by the connector strip 14 and at spaced positions along its length by
additional
short strap connectors 18 so as to connect the endless belts for common
movement
around the rollers and to essentially make the belt assembly functionally
rotate
around the rollers as a one piece assembly.
Each belt carries on its exterior surface an array of pick-up fingers 19
inclined rearwardly and outwardly of the belt surface 20 of a conventional
nature.
The fingers are formed in pairs 19A and 19B mounted at spaced positions on a
base
190 which is bolted to the draper belt. The fingers are cranked at a mid point
19D to
form an outer part 19E of larger angle to the surface 20
As best shown in Figure 2,the belts are connected side by side by
firstly the splicing connector strip 15 connecting the ends of the belt
lengths and
spanning across from one belt 13B to the next 13A. The splicing connector 15
extends from an end 15A at a mid span of one belt to an end 15B mid span of
the
next. This continuation of connector strip 15 is used to join and span belts
13B and
13C and also belts 13C and 13D. The middle three connectors are for example
1123
mm long (44.2 inches) 42 mm wide (1.65 inches) with three bends put in using
forming die. Three of these are used to join the four drapers and two
additional 536
connectors 15C are used at the outer ends.
The endless belts are connected additionally by the plurality of plates
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18 arranged in a row at longitudinally spaced positions along the belts 13A
and 13B
and spanning the edges of the belts. The plates 18 are of sufficient length
only to
reach onto the next belt and to provide a connecting point 19F for the first
row of
Finger 19 on one belt and to provide a connecting bolt 18A on the other belt.
The
number of plates is selected relative to the array of fingers 19 so that each
is
fastened at one end only to the finger 19 and at the other end is fastened to
the belt
without a finger 19. Further plates 18 are used to join belts 13B and 13C and
also
belts 13C and 13D.
The intermediate belts 13B' and 13C are connected by the connecting
strips 15 such that the belt length thereof is shorter than the belt length of
the two
side belts.
A tracking guide device 25 is provided at one point on the assembly for
tracking the common belt assembly on the rollers. This is defined by a
peripherally
extending guide groove 25A in the rear drive roller 12 and a groove 25B in the
front
roller 11 rollers together with a guide assembly 26 mounted on an inside
surface of
one of the endless belts for tracking in the guide grooves.
The tracking guide device 26 is defined by a plurality of guide elements
26E mounted in a row on an inside surface of the end belt 13A of the endless
draper
belt assembly at longitudinally spaced positions along the belt length.
Each guide elements comprises a plastic molded body of generally
oval shape bolted to the inside surface of the belt so that each is spaced
from the
next along the belt. The guide element has sides 26A and 26B for engaging
sides of
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the grooves. The guide element has a front and rear wall 26C and 26D extending
in
a direction across the belt.
The grooves 25A and 25 B each have tapered side walls 27 and 28
with the taper angle A is in the range 10 to 20 degrees and preferably of the
order of
15 degrees. The elements have matching tapered sides 26A and 26B but are
narrower than the groove by a distance Of the order of 0.125 inch for
clearance.
The width of the guide elements is therefore governed by the width of
the groove and the guide elements are wider in the transverse direction than
they
are long in the longitudinal direction so that they are relatively short so as
to avoid
interfering with the bend of the draper belt as it passes around the rollers.
Thus the guide elements are typically less than 20mm in length and
preferably of the order of 16 mm to enable the belt to conform to the roller
diameter.
In comparison, the guide elements are greater than 30 mm in width and
preferably of
the order of 36 mm.
The guide elements are fastened by a single bolt 29 through the guide
element and through the belt to a nut 30. The bolt has a round flat head 31
which is
recessed into an interior 32 of the guide element 26E. The guide elements 26E
are
formed with at least one and preferably two prong protrusions 31A, 32A molded
into
the face of the element at the belt at a side of the bolt 29 that engage into
the
surface of the draper belt to prevent rotation of the guide element 26E on the
draper
belt to ensure its proper orientation for tracking in the grooves.
Some of the bolts 29 connecting the guide elements to the belt
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assembly also are arranged to attach a respective one of the finger members 19
to
the draper. As the number of guide elements 26E required is greater than the
number of fingers in the array, there is are typically two additional guide
elements
26F and 26G between each finger member 19 and the next.
5 In
order to provide effective and accurate tracking, it is highly desirable
that the row of guide elements is arranged so that there are least two guide
elements in the groove 25A at any point in time.
The guide elements have a depth into the groove of at least 10 mm
and preferably of the order of 14 mm to not only contain the guide element
inside the
10 roller
groove but also to sufficient surface area on sides of the guide element
relative
to the groove to achieve acceptable wear.
In order to provide a width of the pick-up of the order of 16 feet, the
widest drapers available can be used which are 4 feet wide which allows the
number
of draper belts to be reduced to four. The drapers are connected end for end
with
the center two drapers 13B, 13C being assembled to a slightly shorter overall
length
with the difference in length between the intermediate belts and the end belts
being
of the order of 15.4 mm. This shorter assembled length results in similar
draper
tension to the outer draper belts 13A and 13D while accommodating the inherent
deflection of the two rollers 11 and 12 under tension.
The end joiner 14 which connects the draper belts end to end spans
across two drapers. In addition to the joiner 14 connecting adjacent drapers
the
numerous metal straps 18 acts to join the drapers.
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The slippage issue is then addressed by having the center drapers
assembled to a shorter assembled length and by joining the four drapers to
essentially make it a functionally one piece draper.
The tracking issue is resolved by attaching in a row the plastic guide
elements 26E to the underside of the draper. These guides are restrained in
the v-
groove 25A in the larger 5" drive roller. The guide elements have a 15 degree
side
taper in the roller groove which restrains the draper assembly from wandering
laterally if deck is twisted or the roller tension at roller side structure is
not guiding
draper assembly adequately.
The customer can adjust the tension in the belts by adjusting the
spacing between the rollers 11 and 12 to desired amount so that draper never
slips
under any condition but keep low enough draper tensions so as to not cause
undue
stress on draper or roller connections. The system allows the simple one piece
rollers to naturally deflect without concern of the center draper belts not
being
tensioned to same degree as outer two. The system no longer requires outer
roller
tension to be so precisely fine tuned to get the draper to center position
itself
between outer end roller supports. This system allows customer to run the
pickup
deck twisted so that the rollers 11 and 12 are slightly out of parallel for a
long time
without any concerns of draper shifting laterally resulting in draper
wear/failure. The
plastic guide elements in the steel roller grooves at outer end reduces or
eliminates
all the edge draper wear.
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The joining of the four drapers with the connector 15 splicing from mid
span of one draper to mid span of next, plus the small sheet metal plates 18
at 4
inch spacing; essentially turns the four drapers into one. Assembling the two
middle
drapers to a slightly shorter assembled length keeps the draper tension
similar on all
four despite the roller tube bow or bending from the draper pull. The assembly
of
inner two drapers to a shorter assembled length allows thinner wall tubing to
accept
less bending strength and to accept therefore the shorter roller to roller
dimension in
middle. The overall assembled draper length on center two drapers is typically
15.4
mm shorter than outer two. The draper tension is controlled by pushing apart
the
roller weldments outer supports, at deck side structure. Sufficient draper
tension is
required to ensure drapers do not slip on rollers when enough resistant crop
load is
applied, but not so much so as to shorten draper life or overstress roller or
roller
support components. By joining the drapers, any heavy loads at the center
belts
13B and 13C prompting slippage is now be resisted by the outer drapers 13A and
13D. The joining of the drapers also prevents crop debris from getting inside
the
draper assembly and building up on the rollers. Build-up of material on the
rollers
can cause conveying issues and tracking issues and damage to drapers.
The plastic guide elements bolted to the underside of the draper edge
are typically spaced 66 mm apart and are short (16 mm) to enable the draper to
conform to the roller diameter. The guides are wide (36 mm) to keep the guide
from
turning as it is going around the rollers as this would not allow the draper
to conform
to roller radius. The guides also have two prong protrusions that engage into
the
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draper and assist in keeping guide from rotating. The elevator bolt head is in
the
interior of the guide to ensure there is no contact with roller. The guide has
square
hole that the square neck of elevator bolt goes into. Assembly requires
holding the
plastic guide as the nut is tightened on top side of draper (or top side of
finger).
There are always at least two guides in the drive roller groove at any point
in time.
Some guides are connected to the draper with same bolt that is attaching
finger. In
between these before mentioned guides are two guides attached to the draper.
There are therefore typically 18 guides on the outside draper. Thus if roller
to roller
distance were increased the number of guides should be increased as it is
desirable
to have at least 2 guides in drive roller groove at all times to ensure
tracking is
maintained. These guides which are restricted in the drive roller groove
control the
lateral position of the four joined drapers and make sure the outer edge of
the draper
doesn't contact side structure, which could result in draper damage. An offset
flange
(not shown) is provided in the side structure to deflect crop from getting to
the outer
edge of the draper and hence getting underneath the draper.
The idler roller groove is wider than the drive roller groove to allow
deck structure twist (allow wheels to follow rolling ground-terrain) and allow
draper to
laterally shift slightly on-the idler roller. The sides of the idler groove
never touch the
sides of the guide elements. The narrower drive roller groove controls the
position
of the draper assembly.
Uneven ground terrain can twist the support deck structure resulting in
misalignment of the front and rear rollers. This twisting of the deck
encourages the
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draper to shift laterally. Also a short wide draper is extremely difficult to
control
lateral positioning. The plastic guides in the drive roller groove guide into
groove as
guide approaches and engages into roller groove. A lesser angle than 15
degrees
would allow guide to get up onto roller outside diameter. An increase in angle
would
not provide enough side support to contain guides inside groove, especially if
deck
assembly is left twisted for a long period of time. The 14 mm depth of guide
is also
important to not only contain guide inside roller groove but to provide enough
surface area on the sides of the plastic member to achieve acceptable wear.
