Note: Descriptions are shown in the official language in which they were submitted.
~4608~
.
APPARATUS FOR CHOPPING AND DISCHARGING STRAW FROM A
COMBINE HARVESTER
BACKGROUND OF THE INVFNTI0N
This invention relates to an apparatus for choppin~ and
S .li:,cl~a(~ straw from a combine harvester which includes a plurality of
blade members mounted on a hub for rotation about an axis of the hub with
the blade members bein~ arran~ed at spaced positions along the length of
the hub sulJ~ldlll "y in radial planes of the hub so as to pass between a
plurality of axially spaced stationary blades a~ain arranged in radial planes of10 the hub. The straw and other material discharged from the combine is fed
into one side of the housin~ of the apparatus onto the hub and the material
is carried around by the hub past the stationary blades in a choppin~ action.
The material is then dis,,l,a~u~:d from a discharge opening in the housin~ for
collection or spreadin~ across the field.
The present invention is particularly an improvement over the
arrangement disclosed in U.S. Patent 5,232,405 of the present inventors
issued Au~ust 3, 1993 based on an applicdli~ filed January 7, 1992. This
d"d,~el"e"l shows a support plate Iyin~ in a radial plane and an additional
plate or flap at ri~ht anùles to the support plate to so that the additional
plate lies lon~itudinally of the hub. The additional plate is inclined so that aradially outer ed~e of the additional plate lies an~ularly forwardly of a
radially inner ed~e of the plate. The additional plate is welded across a
trailin~ edùe of the support plate and extends out to both sides of the
support plate.
This arran~ement has achieved some commercial and technical
success and the present invention is directed to a yet further improvement
which builds upon the improvement of the previous patent.
2 ~ 8 9
.
A further arrangement relevant to the prcsent invention is that
shown in U.S. Patent 5,042,973 of ~d"""d,~l,dnd which discloses a similar
choppin~ and discharge apparatus having rotatin~ blade members carried on
a hub and stationary blades fixed to the housin~. The blade members are
5 mounted in pairs so that a single lug carried on the hub supports a
transverse pin parallel to the axis of the hub with the blade members
mounted on respective sides of the lug and carried on bushings mounted on
the pin. The blade members are spaced so that each blade member passes
between two of the stationary blades in a cuttin~ action. The blade
10 members are shaped so as to be arch shaped in each cross section
transverse to the len~th of the blade member thus definin~ a sharpened
cutting ed~e at the leading edge and a sharpened cutting edge at the trailin~
edge with a centre section of the blade bowed outwardly of a plane
COI ' ' 1'19 the leadin~ and trailing edges. The blades are shown in face to
5 fac2 or back to back a,,c,il~er,,e,~L:, of the pairs.
A yet further arrangement is shown in U.S. Patent 3,693,335
(Mathews) which shows blades which are inclined from the normal radial
plane so as to extend outwardly from the hub in a direction which is inclined
to the radial and axial directions.
20 SUMMARY OF THF INVFI~ITION
It is one object of the present invention to provide an improved
chopper and discharge apparatus of the same general type as shown in the
above patent of the present inventor and which is modified so as to provide
an improved chopping effect while reducing horsepower use and ", , ,;.,9
25 or ill~ r~d:,i"~ the distribution effect.
It is a further object of the present invention to provide an-
improved apparatus of the above general type which is simpler and more
accurate for manufacture.
, , ,
21~ 9
According to one aspect of the invention there is provided a
chopper and discharge apparatus for use with a combine harveste~ having a
combine harvester body, means for ui~cha-~;.,g separated straw from a rear
discharge area of the combine harvester body, and means mounting the
5 apparatus on the combine harvester body at a position adjacent the rear
discharge area for receiving straw therefrom, the apparatus coi"pri~i"~, a
housing having a feed opening and a discharge opening, a plurality of
stationary blades mounted in the housing in axially spaced positions
Iller~along, the stationary blades Iying in parallel radial planes; a chopping
10 assembly mounted in the housing and comprising a hub member mounted
for rotation about a longitudinal axis of the hub member and a plurality of
blade members mounted on the hub member for rotation therewith about
said axis, each blade member projecting generaily outwardly from the hub
member suL.~ "lially in a radial plane of said axis, the blade members being
15 arranged at spaced positions along the length of the hub member such that
rotation of the hub member causes each blade member to pass between two
of the stationary blades in a cutting action; the feed openin~ being arranged
to deposit the material onto the chopping assembly in a direction generally
inwardly toward the axis and the discharge opening being arranged to allow
20 discharge of the material generally radially outwardly from the chopping
assembly; each of at least some of the blade members defining fan blade
members including a first cutting portion which includes a slla,~.el~ed leading
edge Iying in a radial plane of the axis and a trailing edge, and a second flap
portion bent from the first portion at the trailing edge of the first portion so25 as to be contiguous with the first portion at the trailing edge and to extendfrom the trailing edge of the first portion outwardly to one side only of the
radial plane and including a side edge of the flap portion opposite to the
trailing edge which is spaced axially of the radial plane.
21~6~
According to a second aspect of the invention there is provided
a chopper and discharge apparatus for use with a combine harvester having
a combine harvester body, means for di,~ ars~:.,g separated straw from a
rear discharge area of the combine harvester body, and means mounting the
5 apparatus on the combine harvester body at a position adjacent the rear
discharge area for receiving straw therefrom, the apparatus comprisin~; a
housing having a feed opening and a discharge opening, a plurality of
stationary blades mounted in the housing in axially spaced positions
therealong, the stationary blades Iying in parallel radial planes; a chopping
10 assembly mounted in the housing and comprising a hub member mounted
for rotation about a longitudinal axis of the hub member and a plurality of
blade members mounted on the hub member for rotation therewith about
said axis, each blade member projecting generally outwardly from the hub
member sul,~ y in a radial plane of said axis, the blade members being
15 arran~ed at spaced positions along the length of the hub member such that
rotation of the hub member causes each blade member to pass between two
of the stationary blades in a cutting action; the feed opening being arranged
to deposit the material onto the chopping assembly in a direction generally
inwardly toward the axis and the discharge opening being arranged to allow
20 discharge of the material ~enerally radially outwardly from the chopping
assembly; some of the blade members definin~ fan blade members including
a first planar cutting portion which lies in a radial plane of the hub axis and a
second flap portion at a trailing edge of the first portion extending from the
trailin~ edge of the first portion outwardly to at least one side of the radial
25 plane; some of the blade members defining flat blade members each of
which is defined solely by a planar cutting portion Iying in a radial plane of
the hub axis; wherein there are more flat blade members adjacent a center
of the hub member than adjacent ends of the hub member.
~ ~14~08~
According to a third aspect of the invention there is provided a
chopper and discharge apparatus for use with a combine harvester having a
combine harvester body, means for disclla,S, 19 separated straw from a rear
discharge area of the combine harvester body, and means mounting the
5 apparatus on the combine harvester body at a position adjacent the rear
discharge area for receiving straw therefrom, the spparatus comprising; a
housing having a feed opening and a discharge opening, a plurality of
stationary blades mounted in the housing in axially spaced positions
therealong, the stationary blades Iying in parallel radial planes; a chopping
10 assembly mounted in the housin~ and comprising a hub member mounted
for rotation about a longitudinal axis of the hub member and a plurality of
blade members mounted on the hub member for rotation therewith about
said axis, each blade member projecting generally outwardly from the hub
member sui~lallLi~ ly in a radial plane of said axis, the blade members being
15 arranged at spaced positions along the length of the hub member such that
rotation of the hub member causes each blade member to pass between two
of the stationary blades in a cutting action; the feed opening being arranged
to deposit the material onto the choppin~ assembly in a direction generally
inwardly toward the axis and the discharge opening bein~ arranged to allow
20 ~;,chalye of the material generally radially outwardly from the chopping
assembly; each of at least some of the blade members defining fan blade
members including a first cutting portion which includes a sharpened leadin~
edge Iying in a radial plane of the axis and a trailing edse, and a second
planar flap portion bent from the first portion at the trailing edge of the first
25 portion SUb~dl " '~y at right an~les thereto so as to be contiguous with the
first portion at the trailing edge and to extend from the trailing edgè of the
first portion outwardly to one side only of the radial plane; wherein each fan
blade member includes a conlle-,lio,~ portion contiguous with the first
6 214!iQ89
portion and extending therefrom to a support member on the hub member,
the connection portion Iying in a radial plane offset to a side of the radial
plane of the first portion opposite to the second portion so as to balance the
center of gravity of the blade member to lie radially outwardly of the
S connection portion.
One ~",IJC "e"~ of the invention will now be described in
conjunction with the acc~"",d"ying drawings in which:
BRIEF DESCRlPTiON OF THE DRAWlN~iS
Figure 1 is a vertical cross sectional view through a chopper
and distribution apparatus according to the present invention.
Fi~ure 2 is a cross sectional view along the lines 2-2 of Fi~ure
1.
Figure 3 is a side elevational view of one fan blade member of
Figure 1 on an enlarged scale.
Figure 4 is a front elevational view of the fan blade member of
Figure 3 on the same scale as Figure 3.
In the drawings like ~l~ala. ~ID of reference indicate
co~ Dpon.l;"g parts in the different figures.
D~T~Il Fn DESCRIPTION
The chopper and discharge a"d,1ge"~e"l shown in Figure 1 is
very similar to that from the âbove prior patent of the present inventor
which is patent number 5,232,405 the disclosure of which is incorporated
herein by reference. The apparatus therefore comprises a housing 10
defined by a top wall 11, a bottom wall 12 and two end walls 13. The end
walls 13 include dlld~ lll means Sl llellldli~ âlly indicated at 14 for
dlldcl""e"l of the housing to the outlet of a combine harvester for discharge
of straw and possibly chaff from the combine harvester into an inlet opening
15 of the housin~ 10. The bottom wall 12 defines a semi-cylindrical portion
7 21460~9
extending from the inlet 15 to an outlet 16 through which chopped straw
and air is ~;~cllal~ed at relatively high velocity for spreading across the field
or for 1, dl l~pOI Ld~iol ' into a container.
Within the housing is mounted a hub 17 which is carried on
5 suitable bearings (not shown~ for rotation about a hub axis 18 at a centre of
the housin~ so that blade members 19 carried by the hub sweep around
within the housing to entrap straw fed through the inlet 15 and to carry the
straw and air passed stationary blades 20 for choppin~ and for discharge
through the outlet 16. The stationary blades 20 are mounted on the
10 housing at a position appr~ i",al~ly midway between the inlet 15 and the
outlet 16 so that the blade members 19 sweep between the stationary
blades in a cutting action.
The hub 17 carries a plurality of lugs 21 at angularly and axially
spaced positions ll,e,~along with each lug mounting a pair of blade members
15 as described in more detail her~;"d~ r for pivotal movement of the blade
members about a pin 22 parallel to the axis 18.
From Fi~ure 2 it will be noted that the lu~s 21 are arran~ed in a
spiral pattern around the hub 17. Thus one of the lu~s indicated at 21A is
in the o~i~"l~llion of the hub 17 as shown arranged vertically below the hub.
20 A next one of the lugs 21B is arranged on the hub at 90 from the first lug
21A. The next lug 21C is arranged at 90 from the second lug 218 and
thus extends vertically upwardly in the o~ie"Ld~ion as shown. The pattern
then continues through a fourth lu~ 21D and to a fifth lu~ 21E which is
a~ain aligned with the first lug 21A. Each of the lugs carries a pair of blade
25 members. Each lug is aligned with a respective one of the stationary blades
20 so that each stationary blade has ~soc;~ d with it a respective one of
the lu~s and thus has associdL~d with it the pair of blades carried by that
lu~. Each stationary blade is thus swept by the blade members once for
I
8 2146~89
.
each rotation of the hub with some of the stationary blades being swept at
each of the four 90 positions of rotation of the hub.
The blade members include two types of blade members
including fan blade members 19A and flat blade members 19B. Some of the
lugs, for example 21A and 21B carry two of the fan blade members 19A.
Some of the lugs, for example lug 21 E, carry two of the flat blade members
19B. Some of the lugs carry one fan blade member and one flat blade
member. The blade members are arranged so that there are more of the flat
blade members adjacent a center area 10A of the housing than at an area
1 OB of the housiny which is adjacent one end. It will of course be
appr~ idled that the amount of airflow ~qenerated by the fan blade members
is si~nificantly greater than that generated by the flat blade members. Thus
an increase in the number of fan blade members adjacent the ends of the
housing causes an increase in airflow in those areas and it is this airflow at
the ends of the housing which assist in di~r llar~ 9 the straw materials
outwardly to the sides of the chopper. In the center area of the chopper
there is less req~ ~",e,ll for hi~h air velocity and movement since the straw
di,~ lldl!Jed at the center section is directed rearwardly from the chopper and
hence does not require to be di:,chal~ed over such a great distance. The
use of flat blades at the center section reduces manufacturing cost and also
reduces horse power requirements due to the reduced amounted of air
movement at the center section.
Turning now to FiQures 3 and 4, the fan blade members are
shown in more detail. Each fan blade member co""~,ises a first portion 30
which lies in a plane 31 which is radial to the axis 18. The first portion 30
is flat except that it inc!udes at its leading edge 33 spaced forwardly bf a
trailin~ ed~e 34. The bevel 32 is arran~ed so that the leadinQ ed~e 33 is on
a side of the flat planar first portion 30 which lies i"l"ledial~:ly adjacent the
9 2146~9
stationary blade 20 From that leading edge the bevel 32 is inclined
rearwardly and away from the stationarV blade 20 to a second side surface
35 of the first portion 30
The trailing edge 34 of the first portion of the blade includes a
first portion 36 which is parallel to the trailing edge 33 and a second portion
37 which is inclined radially outwardly and forwardly from the portion 36 to
a position immediately adjacent the bevel 32
The blade 19A further includes a second flap portion 38 which
is formed by bending the sheet metal forming the first portion at the trailing
edge portion 37 outwardly at right angles to the plane of the first portion
30 The flap portion is thus planar and lies in a plane longitudinal of the axis
18 The flap portion has an outermost edge 39 parallel to the trailing edge
portion 37 so that the width of the flap portion as shown best in Figure 4 is
constant from a mid height of the flap portion to a bottom edge 40 of the
flap portion which is coe~ sh/e with a bottom edge 41 of the first portion
30 at the bottom of the bevel 32 The edge 40 is thus parallel to the axis
and arranged closely adjacent the outer wall 12 An upper edge 42 of the
flap portion is inclined upwardly and axially from the upper end of the side
edge 39 to the point where it intersects with the trailing edge portion 36
The first and second portions therefore are manufactured from
bending a single piece of metal and the flap portion extends only to one side
of the plane 31 co" ,;,l9 the cutting edg~ 33
The blade member 19A further includes a connection portion
43 with a hole 44 receiving the pin 22 The connection portion 43 is
contiguous with the first portion 30 and includes two shallow bends 44 and
45 so that the ~,o,-~-e~,lioll portion 43 is parallel to the first portion 30 but
lies in a radial plane 46 which is axially offset from the plane 31 in the same
direction as the direction of the bend of the flap portion so that a centre of
lo 2~ 46~89
.
gravity ~p~u~d~alely indicated at 50 lies directly radially outwardly from the
.onne- Lir~n portion 43 and Iying approAi",al~ly in the plane 46. Thus the
centrifu~qal forces acting on the centre of gravity tend to pull the fan blade
member directly outwardly from the pin without any twisting of the blade on
the pin 22.
The pin 22 is formed as a bolt with a head 22A and a nut 22B
and supports bushings 22C and 22D which engage and carry the two fan
blade members 19A carried on the pin 22. The bushings thus hold the fan
blade members 19A at a required spacin~q relative to the lug 21 and thus
relative to the stationary blade 20 to ensure passage of the cuttin~q edge 33
as close as possible to the stationary blade without the danger of
interengagement therebetween.
The fan blade members are arranged as pairs including a
lefthand member and a righthand member for engagement at respective
ends of the pin 22. Thus the cutting edge 33 of each of the blades passes
closely adjacent the stationary blade and the second flap portion 38 projects
outwardly from that side of the first portion which is opposite to the
stationary blade.
As explained in the above previous patent, the i"cli"~ion of the
second flap portion of the fan blade member so that a radially outer most
end 40 thereof lies angularly forwardly of a radially inner trailing end 47
thereof ~enerates a high level of air movement to pump air from the inlet
throu~h the outlet to generate high velocity in the straw pieces which are
ejected from the outlet.
The fan blade member including the first portion, the second
flap portion and the conne. li~,g portion are all formed from a single piece of
sheet metal which can be stamped and bent to the required shape with a
high deqree of accuracy so that each blade member has the same wei~qht
089
and the same angles thus enabling the manufacture of the product to higher
loleral1ces and increased balance of rotation of the blades about the hub
axis.
As shown in Figure 4, the positioning of the lugs 21 and the
5 width of the flap portion is arranged relative to the spacing between the
stationary blades so that a next adjacent fan blade member as it passes
between the stationary blades overlaps the path of movement of its
neighbor. In addition, the spacing of the stationary blades relative to the
width of the fan blade is arranged so that the outside edge of the flap
10 portion passes the next adjacent stationary blade at â greater spacing than
the spacing between the cutting edge and the associated stationary blade
but not at such a large spacing to exclude the cutting effect between the
outside edge and its associated stationary blade. Each blade therefore
passes between two stationary blade and causes a cutting effect in
lS cooperation with both the stationary blades. The overlap also prevents any
area of the housing which is not effectively swept by the fan blades as they
rotate around the axis of the hub. In one example, the spacing between the
stationary blades is of the order of 2.0 inches while the width of the fan
blade is of the order of 1.25 inches giving an overlap of the order of 0.5
20 inches.
As shown in Figure 2, the flat blade members 1 9B do not
include the bend sections 44 and 45 so that the flat blade member lies in a
common radial plane. For this reason the bushing 22E mountin~ the flat
blade member 1 9B is narrower than the bushing 22D mounting the fan blade
25 member. This ensures that the clearance between the cutting edge of the
flat blade member and the cutting edge 33 of the fan blade member is
eqll " Illy spaced from the stationary blade.
12 21~6~89
.
In an alternative dllal~eillellL ~not shown) no flat blades are
used so that all the blades are of the fan blade type. In a yet further
arran~ement, the blades are not mounted in pairs but are instead mounted
on individual mounting lugs at the angular and axial spaced positions
5 previously described.
Since various modifications can be made in my invention as
herein above described, and many apparently widely different embodiments
of same made within the spirit and scope of the claims without departing
from such spirit and scope, it is intended that all matter contained in the
10 accolllpall~ing speciricdlion shall be i"l~".rt:Led as illustrative only and not in
a limiting sense.
