The present invention relates to an elevator for an agricultural
harvesting machine which is equipped for collecting crop material from a field and
processing the same. In particular, it relates to the elevator which conveys the
collected crop to the crop processing means.
Agricultural harvesting machines such as combine harvesters
generally are developed to handle a large variety of crops. For example a combine
harvester may be used to harvest small grain crops such as wheat and rye, rape or
grass seed or large grain crops such as peas or corn. In this manner the use of
the harvester, which is a high investment tool, can be extended over a longer season.
Conventionally the harvester is equipped with a detachable
crop collecting attachment, such as a grain or corn header, which cuts the stems
of the crop standing in the field and conveys the same to the inlet of an elevator
housing. Alternatively crop which has been cut previously can be lifted up from
the field by a pick-up attachment and conveyed to the same inlet. Elevator means,
commonly a chain elevator with transverse slats, grab the collected crop deposited
in front of the inlet and convey it rearwardly and upwardly towards the crop processing
means, conventionally a threshing drum and concave or grate assembly.
As illustrated by
, the crop usually is engaged by the lower run of the chain elevator to
transport it along a bottom plate of the elevator housing. The upper run is shielded
from the lower run by a backing plate which extends between the front and rear transverse
shafts of the elevator. This plate reduces the chances that material which was not
removed from the elevator by the threshing system, falls back on top of the lower
run and gets lodged between the chains and the sprockets driving the chains near
the exit of the elevator. The backing plate equally provides additional support
for the upper run of the chains.
When the machine is harvesting long-stemmed crops, the
intermediate plate should extend forwardly as far as possible to ensure the return
material is deposited in front of the conveyor.
When harvesting corn there is no immediate danger of stem
material getting wrapped around the shafts of the elevator. Corn headers for combines
usually have snaprolls for removing the corn ears (cobs) from the stems and the
headers convey only these ears to the elevator entrance. Near the elevator outlet
most of the ears are immediately grasped by the threshing apparatus, but some ears
may escape and are engaged by the returning slats on top of the backing plate. These
ears slide over the backing plate towards the front of the elevator, where they
forcefully hit the so-called anti-dust plate which is installed at the front end
of the elevator. The returning cobs cause premature wear and deformation of this
front plate. It is an object of the invention to remedy thereto without compromising
the proper operation of the conveyor during the harvest of small grains.
The operator needs easy access to the interior of the elevator
housing, e.g. for removal or installation of the backing plate, for inspection and
replacement of the elevator slats, for removal of stray material from the shafts,
etc. Commonly, the top wall of the housing has an aperture which is closed by a
cover or by a door, as illustrated in
. Herein the door is connected by a hinge to the upper rim of the aperture.
The size of the aperture is limited as the door has to swing open in the confined
area below the steering platform. To provide additional access the top wall of the
housing is provided with removable panels which are bolted onto housing frame. Such
arrangement does not allow for a quick access to a larger portion of the elevator.
According to one aspect of the invention there is provided
an agricultural harvesting machine comprising crop processing means and an elevator
assembly for conveying harvested crop material to said crop processing means, said
elevator assembly comprising:
characterised in that shielding means are provided with at least one aperture enabling
passage therethrough of crop material, and at least one removable cover for closing
- an elevator housing;
- endless elevator means mounted for rotation in said housing, said elevator means
having lower and upper lower runs; and
- shielding means shielding said lower run from said upper run,
When the harvested crop material contains long stems, which
easily wrap around the drive shaft of the elevator assembly, the cover is installed
to prevent the crop material from falling on top of the lower run. When substantially
heavy crop parts are ingested, such as corn ears, the covers can be removed such
that returning crop parts are trapped in the aperture before they hit a front plate
of the elevator assembly or an auger of the header.
Preferably, the aperture is provided in a front portion
of the shielding means in order to reduce the risk that crop material wraps around
the rear axle of the elevator. The shielding may comprise a set of preferably juxtaposed
apertures which extend substantially the full width of the shielding. In this manner
it is possible to catch corn cobs over the full width of the elevator.
The cover may be provided with a profiled front edge for
hooking over a front border of the aperture, such that the cover may be easily installed
According to another aspect of the invention, there is
provided an agricultural harvesting machine comprising crop processing means and
an elevator assembly for conveying harvested crop material to said crop processing
means, said elevator assembly comprising:
characterised in that said hatch means comprise a split door.
- an elevator housing;
- an endless elevator means mounted for rotation in said housing; and
- hatch means for gaining access to the interior of said housing,
This door arrangement makes it possible to provide a large
service opening without needing a lot of space above the opening for rotating the
door. This is particularly advantageous where the elevator housing is provided below
the steering platform.
The split door may comprise a first lid and a second lid
hingeably connected to the first lid, such that both door elements can be opened
simultaneously. The first lid may by hingeably connected to the housing wall. In
this manner the lids do not have to be put aside the machine during service operations.
The two lids may be locked in place by a single latch mechanism
associated with one of the lids only. Such mechanism preferably comprises at least
one hook for simultaneously preventing longitudinal and vertical movement of the
lid. The hook may be attached to movable member and engage a lug. In one embodiment
the movable member may be movably attached to the housing and the lug may be attached
to the lid. Alternatively, the movable member may be provided on the lid and the
lug on the housing.
In a simple, yet effective embodiment, the lug may have
an extension for hooking over a longitudinal part of the hook. The movable latch
member may be mounted for transverse movement to the housing. The extension may
be profiled to make the hook and the latch member yield when the lid is closed.
The movable latch member may be linked to a pivotable member
which is linked to a pivotable element, such as a hexagonal head, on top of the
housing. The pivotable member may be adapted for pivotment by a tool. Preferably
the pivotable element is disposed near a side of the housing for easy access for
An agricultural harvester in accordance with the present
invention will now be described in greater detail, by way of example, with reference
to the accompanying drawings in which:
- Figure 1 is a diagrammatic, partly sectional side view of a combine harvester
having a forwardly extending straw elevator;
- Figure 2 is cross sectional view of the straw elevator of Figure 1;
- Figure 3 is an isometric, partly exploded view of straw elevator of Figure 1;
- Figure 4 is an isometric view of the top wall of the straw elevator of Figure
2, showing a door closing an opening in this top wall;
- Figure 5 is an isometric view of the top wall of Figure 4, showing the door
in a partly open position;
- Figure 6 is an isometric view of a detail of the lock mechanism of the door
of Figure 4:
The terms "grain", "straw" and "tailings" are used principally
throughout this specification for convenience but it is to be understood that these
terms are not intended to be limiting. Thus "grain" refers to that part of the crop
material which is threshed and separated from the discardable part of the crop material
which is referred to as "straw". Incompletely threshed crop material is referred
to as "tailings". Also the terms "forward", "rearward", "left" and "right", when
used in connection with the combine harvester and/or components thereof are usually
determined with reference to the direction of forward operative travel of the combine
harvester, but again, they should not be construed as limiting. The terms
"longitudinal" and "transverse" are determined with reference to the
fore-and-aft direction of the harvester and are equally not to be construed as limiting.
The combine harvester 10 shown in Figure 1 of the accompanying
drawings, is of the axial-flow type, wherein crop material is threshed and separated
while it is advanced by and along a longitudinally arranged rotor 27. The combine
harvester comprises a chassis or main frame 11 having a pair of driven, ground-engaging
front wheels 12 and a pair of smaller, steerable rear wheels 13. Supported on the
main frame 11 are an operator's platform 14 with an operator's cab 15, a threshing
and separating assembly 16, a grain cleaning assembly 17, a grain tank 18 and a
power plant or engine 19. A conventional grain header 22 and a straw elevator assembly
23 extend forwardly of the main chassis 11 and are pivotally secured thereto for
generally vertical movement which is controlled by appropriate actuators, such as
hydraulic cylinders (not shown).
As the combine harvester 10 is propelled forwardly over
a field with standing crop, the latter is severed from the stubble by a sickle bar
24 at the front of the header 22 and delivered by a header auger 25 to the inlet
of the straw elevator assembly 23, which supplies the cut crop to the threshing
and separating assembly 16.
The threshing and separating assembly 16 comprises a generally
cylindrical chamber 26 in which a rotor 27 is rotated to thresh and separate the
crop received therein, that is to say, the crop is rubbed and beaten between the
rotors 27 and the inner surfaces of the chambers 26, whereby the grain, seed or
the like, is loosened and separated from the straw.
Grain which has been separated by the threshing and separating
assembly 16 falls onto a first grain pan 30 of the cleaning assembly 17 which further
also comprises a pre-cleaning sieve 31, positioned above a second grain pan 32,
a pair of sieves 33, 34, disposed the one above the other, and a cleaning fan 35.
The grain pans 30, 32 and the sieves 31, 33, 34 are oscillated generally back-and-forth
for transporting threshed and separated grain from the first grain pan 30 to the
pre-cleaning sieve 31 and the second grain pan 32 and therefrom to the sieves 33,
34. The same oscillatory movement spreads said grain across said sieves 31, 33,
34, while permitting the passage of cleaned grain by gravity through the apertures
of these sieves. The grain on the sieves 31, 33, 34 is subjected to a cleaning action
by the fan 35 which provides an air flow through said sieves to remove chaff and
other impurities such as dust from the grain by making this material airborne for
discharge from the machine through an outlet 37 of the straw hood 38.
Clean grain falls to a clean grain auger 40 in a clean
grain auger trough 41 and is subsequently transferred therefrom by a grain elevator
44 to the grain tank 18. Tailings fall to a tailings auger (not shown) in a tailings
auger trough 42. The tailings are transported sideways by said tailings auger to
a separate rethresher 43 and returned by a tailings conveyor 45 to the cleaning
assembly 17 for repeated cleaning action.
A pair of grain tank augers 46 at the bottom of the grain
tank 18 is used to urge the clean grain sideways to an unloading tube 47 for discharge
from the combine harvester 10.
As shown in greater detail in Figure 2, the straw elevator
assembly 23 comprises a welded, substantially parallelepiped housing 50 which is
pivotably secured to the main frame 11 below the operator's platform 14. The housing
50 comprises an upper wall 52 and a lower wall 53, interconnected by a pair of side
walls 54. The rear end of the housing 50 is provided with a transverse drive shaft
56 which extends through the side walls 54 and is provided with a plurality of (e.g.
four) sprockets 57. At the front end of the elevator assembly 23, a drum 59 is installed
for rotation between the side walls 54. The drum has a front shaft 60 extending
through apertures in the side walls and received in bearings 61 which are mounted
to pivot arms 63. At their rear ends these arms 63 are pivotably affixed to the
outside of the side walls 54 at pivots 64.
The elevator assembly 23 includes elevator means comprising
a plurality of endless, flexible members, e.g. chains 66, which are trained along
parallel paths over the sprockets 57 and the front drum 59. The chains are driven
by the sprockets 57 on the drive shaft 56. Mounted across and to the chains is a
plurality of generally transverse slats.
The lower wall 53 of the housing 50 may be provided with
a wear plate along which the lower run 66a of the elevator means conveys the harvested
crop to the inlet of the threshing and separating assembly 16. During operation
of the elevator assembly 23, the drive shaft 56 is rotated CCW as seen in Figure
2 to make the slats adjacent the front drum 59 engage and grab the crop material
which is delivered thereto by the header auger 25. The slats of the lower run 66a
convey the crop rearwardly and upwardly along the lower wall 53 or the wear plate,
if present, to the outlet of housing 50, where the crop is combed away from the
elevator means by the front portion of the threshing rotor 27.
In order to prevent that stray material that was not removed
immediately from the elevator means, falls back from the upper run 66b onto the
lower run 66a and starts wrapping around the drive shaft 56 or accumulating around
the sprockets 57, an intermediary shielding means is provided between the lower
and upper runs 66a, 66b of the elevator means. In the present embodiment, the shielding
means consists of a stationary rear plate 70 and a removable front plate 71. The
rear plate 70 is welded between and to the side walls 54 and to a transverse tubular
reinforcement 73 disposed near the drive sprockets 57. The front plate 71 extends
forwardly from the front edge of the rear plate 70 towards the front drum 59 and
is attached by bolt means 75 to the side walls 54 of the housing 50.
The front and rear shielding plates 70, 71 may be provided
with wear strips 76 arranged below the upper run 66b of the conveyor chains. The
wear strips are intended for extending the life time of the plates along which the
chains 66 are permanently moved during harvesting operation.
Between the path of the chains 66, the front plate 71 is
provided with apertures 78 which are closed by covers 79. The covers 79 have a profiled
front edge which hooks over the front border of the aperture 78. At their rear edge
the covers 79 are provided with a flange portion which rests on the front plate
71 and which is secured thereto by bolt means 80. It is envisageable to install
and remove the covers through the inlet of the feeder housing 50, especially where
the apertures 78 are not remote from the front drum 59. Otherwise, as shown in Figure
3, the upper wall 52 may be equipped with a service opening 81 and a hatch 82 above
the apertures 78. The hatch can be opened for removal or installation of the covers
79 below the upper run 66b of the conveyor means.
When the apertures 78 are closed, the shielding means prevent
that returning material is deposited on top of the lower elevator run 66a. Any stray
material which was not removed from the slats near the outlet of the housing 50
is conveyed along the rear and the front shielding plates 70, 71 and finally mixes
with the freshly harvested material which is delivered by the header auger 25 to
the mouth of the elevator assembly 23.
When corn is harvested there is a chance that also some
corn cobs (maize ears) or parts thereof are not immediately grasped by the threshing
rotor 27 and move into the area above the rear shielding plate 70. The ears have
a substantial mass and slide along the shielding means to the front of the housing
50. There they may heavily impact and damage a front plate 84 which is attached
above the mouth of the inlet. If the corn ears follow a somewhat lower trajectory,
they hit the header auger 25. The auger body may be damaged and/or the auger flights
may engage the corn and throw them upwardly or forwardly out of the header 22. To
preclude such impacts, the covers 79 in the housing 50 are removed such that the
corn ears can fall to the lower run 60b before they reach the front end of the housing.
When a combine harvester is used to harvest corn, it commonly
is equipped with a dedicated header which separates the corn ears from the stems
and feeds only the corn ears to the combine harvester. Accordingly the material
ingested by the elevator assembly 23 contains no long, thin straw which is prone
to being wrapped around the drive shaft 56. So, opening the apertures 78 does not
create any supplemental wrapping hazards when corn is harvested.
The provision of the apertures 78 and removable covers
78 enables an effective and simple means for adapting the straw elevator assembly
23 to harvesting either small grains or corn.
The shielding means need not necessarily be provided with
a plurality of juxtaposed apertures 78. It is also is envisageable to have one large
aperture, extending substantially the full width of the housing 50 and being closed
by a single, transverse cover.
The hatch 82 and its latch mechanism 91 are shown in further
detail in Figures 4 to 6. The hatch is constituted by a split access door comprising
a front lid 85, which is attached by a pair of hinges 87 to the front edge of the
service opening 81, and a rear lid 86 which is attached by three hinges 88 to the
rear edge of the front lid 85. The rear lid 86 is provided on its left side with
a handle 89 allowing an operator standing on the left of the elevator assembly 23
to open the hatch 82 for gaining access to the interior of the elevator housing
50. As shown in Figure 5, the rear lid 86 is raised, thereby raising also the rear
of the front lid 85. The rear lid 86 is then pushed forwardly, whereby the front
lid 85 rotates at its hinges 87 until it rests on top of the front portion of the
upper wall 52. Finally, the rear lid 86 is deposited on top of the front lid 85.
The use of such split door makes it possible to close a large service opening 81,
even where the space above the housing 50 is seriously confined by the operator's
platform 14 above. When fully opened, the lids 85, 86 assume a convenient, low and
stable position in front of the opening, where they do not hinder access to the
slats, the wear strips 76 or the covers 79 of the shielding plate 71.
The hatch 82 is closed by a latch mechanism 91 which equally
is operated from the left side of the elevator housing 50. The mechanism 91 comprises
a transverse control slat 92 which is mounted below the upper wall 52 adjacent the
rear edge of the service opening 81. A pair of bolts 94 extending through slots
95 in the slat 92 slideably hold the slat against the inner surface of the wall
52. The slat 92 is provided with first retainer means in the form of a pair of hooks
96 which extend into the area below the opening 81. The hooks are welded to the
slat 92 adjacent the slots 95 and extend through transverse slots 97 provided in
a downwardly extending rim 99 of the service opening 81. The hooks 96 co-operate
with further retainer means in the form of lugs 101 which are attached to the back
of the rear lid 86. A spring 103 mounted between the housing 50 and the control
slat 92 urges the latter sideways such that the hooks 96 are pulled against the
lugs 101. The longitudinal part of the hook rests above an extension 104 of the
lug 101 thereby preventing upward movement of the rear lid 86. The transverse part
of the hook 96 is positioned over the transverse part of the lug 101, thereby preventing
forward movement of the same lid 86. In this manner the latch mechanism 91 firmly
holds in place the rear lid 86. Simultaneously, the front lid 85 is secured as it
is caught between its hinges 87 and the secured rear lid 86.
Near the left side of the elevator housing 50, a lever
106 is pivotably connected to one end of the control slat 92. The other end of the
lever 106 is affixed to the lower end of a hexagonal head 107 which extends through
the upper wall 52. The head 107 and the affixed lever 106 can be rotated by means
of a dedicated or standard tool, e.g. a wrench. A rotation over a small angle shifts
the control slat 92 sideways against the force of the spring 103 and removes the
hooks 96 from the lugs 101, such that the rear and front lids 86, 85 can be lifted
and turned over.
When the head 107 is released, the spring 103 pulls the
control slat 92 back to the left until the ends of the slots 95 contact the bolts
94. After service operations the operator uses the handle 89 to pull the hatch lids
85, 86 over the service opening 81. The extensions 104 of the lugs 101 contact the
hooks 96 of the latch mechanism 91. The extensions are provided with an inclined
lower border which pushes the hooks 96 sideways against the force of the spring
103, until the hooks slide over the tip of the extensions and assume their previous
position over the lugs 101, thereby retaining the rear lid 86 as described above.
Contrary to the opening operation, this closing operation requires no tooling. The
weight of the hatch 82 or a small extra push suffices to make the hooks 96 slide
over the lugs 101 and secure the hatch 82.
Although the present invention has been described with
reference to a particular machine and structure, other embodiments can be thought
of without departing however from the scope of the invention as defined in the claims.
For instance it is possible to replace the two-lid hatch with a hatch comprising
three or more lids.