Note: Descriptions are shown in the official language in which they were submitted.
CA 02212881 1997-11-06
The present invention relates to a combine or threshing machine in general, and
to a removable concave therefor in particular.
BACKGROUND OF THE INVENTION
s
Combines and threshing machines are used in the harvesting of grains and other
crops such as corn to remove the desired grains, for example, from the plant. The
grains are removed from the plant stalk and are deposited in a container carried by the
machine, while the stalks are thrown from the machine to lay on the ground, as chaff.
10 Most, if not all, present day combines and threshing machines remove the grains from
the stalks in essentially the same manner, by passing the plants between a rotating
rotor and a concave, the concave extending along the length of the rotor and being
in close proximity thereto. As suggested by its name, a concave is transversely
arcuate presenting a concave threshing surface to the arcuate rotor. The threshing
15 surface of the concave is constructed as an open grid or mesh so that the separated
grains can pass therethrough to a conveyor which in turn carries the grains to the
container. The size of the grid will depend on the crop being harvested, the grid being
coarser for corn than it is for wheat or oats.
Over time, the threshing surface of the concave will wear or will be damaged,
perhaps by stones and other debris that is picked up during harvesting. A typical
concave is a welded assembly with rectangular cross-members and transverse rods
defining the grid of the concave and its mesh size. The rods pass through the cross-
members below the working edge of each and it is the working edges that will usually
wear, requiring replacement of the concave. There is therefore a need for a new
concave, one that can be readily removed from a combine or threshing machine andreplaced therein, one that can be easily and readily repaired should it become worn
or damaged, and one that can be readily and easily reconfigured to accommodate
different mesh or grid sizes for different crops.
CA 02212881 1997-11-06
SUMMARY OF THE INVENTION
The present invention overcomes the problems of the prior art and meets the
requirements suggested above. The invention provides a concave kit for a combine5 or threshing machine that includes a plurality of cross-bar members pre-drilled with a
set of apertures along the centerline thereof to accept removable grid-defining
subassemblies. The kit also includes side-plate members that can be bolted in place
in the combine or threshing machine, each of which carries a brace member that
receives the ends of the cross-bar members. Brackets and bolts are provided to
10 secure each cross-bar member and associated grid-defining subassembly to an
adjacent end brace member as well as to intermediate brace members so that any
cross-bar member can be removed and replaced if necessary. Furthermore, any cross-
bar member can be turned over to present another working edge to the rotor of the
combine or threshing machine. It is seen that by utilizing the concave kit of this
15 invention it is possible for a farmer to remove the entire concave from his harvesting
equipment and to then repair or rebuild the concave on site, without having to either
buy a new concave or spend considerable time and effort in using welding equipment
to dismantle and rebuild a conventional concave. Additionally, if the harvestingequipment is to be used to harvest a different crop, one requiring a different grid size,
20 it is possible to modify the concave of the present invention
CA 02212881 1997-08-12
merely by replacing the original grid-defining subassemblies with ones having a
different grid size.
Broadly speaking, the present invention may be considered as
providing a kit of components for assembling a concave for cooperation with a
5 rotor of a combine or threshing machine, comprising: a pair of generally arcuate
mirror-image side-plate members including means for removable attachment
thereof within a combine or threshing machine; a plurality of generally arcuate
end brace members each having inner and outer arcuate edges and a plurality of
generally rectangular cut-outs extending into the end brace member normal to
10 the inner arcuate edge thereof, each of the side-plate members having an end
brace member secured to an inwardly facing surface thereof; a plurality of
generally rectangular cross-bar members positionable between the side-plate
members, each of the cross-bar members being receivable at the ends thereof
in a corresponding cut-out of an adjacent end brace member; means for
15 removably securing each cross-bar member to the adjacent end brace member;
and a plurality of removable grid-defining subassemblies extendable between and
normal to each of the cross-bar members, each grid-defining subassembly being
securable to an adjacent cross-bar member; whereby the cross-bar members are
reversible after one longitudinal edge thereof has become worn to present the
20 other longitudinal edge to a rotor of the combine or threshing machine and
whereby said grid-defining subassemblies can be removed and replaced by grid-
defining subassemblies defining a different grid size.
HWR:lcd - 3 -
. CA 02212881 1997-08-12
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 shows a perspective view of a prior art concave, it being
appreciated that a concave constructed in accordance with the present invention
will have a similar appearance.
Figure 2 is a plan view of a side-plate member as used with the
present invention.
Figure 3 is a plan view of a brace member as used with the present
invention .
Figure 4, 5 and 6 are a perspective views of three types of cross-bar
members as used with the present invention.
Figure 7 is a perspective view of a transverse brace member as used
with the present invention.
Figures 8 and 9 are perspective views of two types of angle brackets
as used with the present invention,
Figure 10 shows an end view of the grid-defining subassemblies as
used with the present invention.
Figure 11 illustrates a transverse cross-section through a number of
the components creating a concave adjacent a side-plate.
HWR:lcd - 4 -
CA 02212881 1997-08-12
Figure 12 illustrates another transverse cross-section through the
components of the invention adjacent an intermediate brace member.
Figure 13 illustrates a partial plan view of an assembly of the
components of the present invention.
5 DESCRIPTION OF THE PREFERRED EMBODIMENT
Figure 1 illustrates a prior art concave 10, all components of which are
welded together, meaning that the entire concave must be replaced if such
components are worn or if a new crop is to be harvested, one requiring a
different grid size. The concave 10 includes arcuate end members 12, a plurality10 of transverse cross-bar members 14, back braces 16 and a plurality of rod-like
grid members 18 spaced apart across the concave and extending between
adjacent cross-bar members at right angles thereto. The grid members and the
cross-bar members define the grid of the concave, with the uppermost edges of
the cross-bar members defining the threshing surface of the concave subjected
15 to the rotor of the machine.
The present invention takes the conventional concave 10 as seen in
Figure 1 and breaks it down into a number of separate components and
subassemblies which can be assembled and disassembled at will. It is possible
to remove and replace worn or broken parts and it is possible to rebuild a
20 concave to accommodate different crops requiring different grid sizes. When the
components of the present invention are assembled together the appearance of
the resulting concave will be essentially the same as that of a conventional
concave, such that the new concave could easily replace a conventional concave
in a combine or threshing machine.
HWR:lcd - 5 -
CA 02212881 1997-11-06
Figures 2 through 8 illustrate the various components of the concave of the
present invention. In Figure 2 the first component to be discussed is the side plate
20 manufactured from hot rolled steel plate of about 10mm (.375n) thickness. The5 side plate has generally arcuate inner and outer edges 22 and 24 respectively with
large and small diameter mounting holes 26 and 28 respectively therethrough.
Welded to the side plate 20 as seen in Figure 3 is an end brace member 30 which is
shorter than a side plate and has arcuate inner and outer edges 32 and 34
respectively. Spaced apart along the length of the inner edge 32 is a plurality of
10 generally rectangular cut-outs 36 extending into the body of the brace member 30
generally normal to the inner edge 32. The length of the brace member is less than
that of the side plate 20 so that the mounting holes 26, 28 are not obstructed by the
brace member 30. Additional or intermediate brace members 30' are provided, as
discussed hereinafter, for extra support of the concave components after assembly.
Figures 4, 5 and 6 show three types of cross-bar members used with the
present invention. Figure 4 shows a first cross-bar member 38 having a length ofabout 165cm (65"), a thickness of about 10mm (.375") and a depth of about 6.4cm
(2.5"). The material is preferably a 1045 hot rolled carbon steel. Spaced apart along
20 the length of the cross-bar 38 is a first plurality of square holes 40 positioned on the
centerline of the member. The holes are symmetrically located with respect to the
longitudinal center of the member although the spacing is not uniform from hole to
hole. The cross-bar member has longitudinal edges 42 and 44, one of which will be
the working or threshing edge once the concave has been assembled. Figure 5 shows
25 a second type of cross-bar member 46 having a plurality of holes 48 which are also
symmetrically located with respect to the longitudinal center of the member but with
a different, non-uniform spacing when compared to the first member 38.
CA 02212881 1997-08-12
A typical concave assembly will utilize six of the first cross-bar members 38 and
five of the second cross-bar members 46, with the cross-bar members 46
alternating with the cross-bar members 38. Each cross-bar member is adapted
to be received within a cut-out 36 of a brace member 30.
Figure 6 illustrates the third type of cross-bar member, namely front
and rear cross-bar members 50, 50' respectively which are sized the same as the
members 38, 46 and made of hot rolled steel. Each cross-bar member 50, 50'
has mounting holes 52 therethrough along the centerline thereof, the spacing of
the holes 52 being different again from the spacing of the holes 40 and 48 foundin the cross-bar members 38 and 46 respectively. Close to one edge 54 of the
cross-bar member 50, 50' is a plurality of small diameter (6.4 mm or l/4") holes56 provided in uniformly spaced groups of seven holes, with each group being
separated from each other by a distance somewhat greater than the spacing
between holes.
Figure 7 shows a transverse brace member 58 of 6.4 mm (1/4") hot
rolled steel having essentially the same length and depth of a cross-bar member.Each brace member 58 has a plurality of spaced apart holes 60 along the
centerline thereof and a plurality of small diameter holes 62 adjacent to one
edge, the holes being provided in groups that are aligned with the groups of
holes 56 provided in the front and rear cross-bar members 50, 50'.
Figures 8 and 9 illustrate, in perspective, two types of angle brackets,
a small bracket 64 and a large bracket 66. Both brackets have a short leg 68
and a longer leg 70 or 72 as the case might be, the leg 70 being associated withthe small bracket 64 and the leg 72 being associated with the bracket 66. The
25 longer leg of bracket 64 is provided with an aperture in the form of an oblong
HWR:lcd - 7 -
CA 02212881 1997-08-12
through hole 74, while the longer leg of bracket 66 is provided with an aperturein the form of a slot 74'.
Figures 10, 11, 1Z and 13 illustrate the assembly of the various
components of this invention to create a new concave. Initially the brace
members 58 are paired as shown in Figure 10 with a 6.4 mm (1/4/') diameter rod
76 extending between each pair of aligned holes 62, from one brace member to
the adjacent brace member. Rods of slightly different lengths are used to createthe desired arcuate nature of the concave, a typical concave of this invention
utilizing 540 rods that are 3.25 cm (1.278") long, 60 rods that are 3.74 cm
(1.471") long, 60 rods that are 4.23 cm (1.665") long and 60 rods that are
5.07 cm (1.977") long. Each rod is welded at its end to the adjacent brace
member 58. It is also noted in Figure 10 that one set of rods 76 extends
between a brace member 58 and the front cross-bar member 50 while another
set of rods 76 extends between a brace member 58 and the rear cross-bar
member 50'. The combination of rods and transverse brace members, or rods,
transverse brace member and front or rear cross-bar member creates the
aforementioned grid-defining subassembly of the present invention.
Figure 11 illustrates the assembly of components at one end of the
concave. There, a side plate 20 is shown with a brace member 30 Iying
thereagainst and welded thereto. Alternating cross-bar members 38 and 46 are
shown resting in the cut-outs 36 with the front cross-bar 50 resting against andwelded to the forward edge 78 of the brace member and the rear cross-bar 50'
resting against and welded to the rear edge 80 of the brace member. The
transverse brace members 58 with rods 76 extending therebetween are
positioned with one of the pairs of brace members 58 being positioned against
the adjacent face of one cross-bar member while the other brace member of the
HWR:lcd - 8 -
. CA 02212881 1997-08-12
pair is positioned against the adjacent face of the adjacent cross-bar member.
Along the length of each cross-bar member an angle bracket 64 or 66 is located
at each mounting hole 52 of each cross-bar member. The brace members are
connected to the cross-bars by way of a bolt 82 extending through a hole 74 or
a slot 74' of an angle bracket 64 or 66, a hole 60 of a first brace member 58,
a hole 52 of the cross-bar, and a hole 60 of the other brace member 58. A nut
84 is threaded onto and tightened on each nut 82 as seen in Figure 11.
From one cross-bar member 38 to an adjacent cross-bar member 46
the small angle brackets 64 are positioned so that the longer legs 70 thereof
10 extend in opposite directions as shown in Figure 13. The short leg 68 of eachsuch angle bracket abuts an intermediate brace member 30' which is identical
to a brace member 30 but is positioned at a location spaced from the end of the
concave and in alignment with the gap between groups of holes 56 or 62 as
seen in Figure 12. In the illustrated version of the present invention there are15 eight of the intermediate brace members 30' spaced along the length of the
concave, there being one end brace member 30 at each end, welded to the
adjacent end plate 20 as previously described. Each angle bracket short leg 68
is welded to the adjacent side of the adjacent intermediate brace member 30',
while the short leg of each angle bracket 64 or 66 adjacent the respective end
20 brace members 30 is welded thereto as well. The respective end edges of the
intermediate brace members 30' are welded to the front and rear cross-bar
members 50, 50'.
From the foregoing it will be seen that the components as described
herein are used to create several subassemblies that can be used to create new
25 and different concave configurations or to repair worn or broken concaves. One
subassembly includes an end plate 20 having an end brace member 30 welded
HWR:lcd - 9
. CA 02212881 1997-08-12
thereto, there being alternating small and large angle brackets 64, 66 welded tothe end brace member at alternating cutouts 36, and front and rear cross-bar
members 50, 50' welded to the forward and rear end edges 78, 80 respectively
of the end brace member 30. A second subassembly is formed by each
5 intermediate brace member 30' having angle brackets 64 welded thereto as
described above, with each intermediate brace member being welded to the front
and rear cross-bar members as described above. A third subassembly is formed
by the spaced transverse brace members 58 with the plurality of rods 76
extending therebetween as seen in Figure 10 and is the grid-defining
10 subassembly referenced hereinabove.
A basic framework for a concave is formed by the first and second
subassemblies described above. To create a concave one need only insert the
cross-bar members 38, 46 into the cutouts 36 of the end and intermediate brace
members and then insert the third subassemblies into the cutouts so that a
15 transverse brace member 58 abuts a face of the cross-bar member. Then the
bolts 82 are pushed through the aligned holes of the angle brackets, transverse
brace members and cross-bar members, and the nuts 84 threaded onto the
threaded end of the respective bolt and tightened thereon.
If it is necessary to replace a broken or a worn cross-bar member one
20 need only remove the concave from the combine or threshing machine, undo the
bolts and nuts along the cross-bar member that needs to be replaced, pull the
cross-bar member out from the cutouts 36 of the end and intermediate brace
members, reversed so that the longitudinal edge 42 which was originally at the
base of the cutouts becomes the working edge, exposed to the rotor of the
25 combine or threshing machine. The bolts and nuts are replaced and retightenedand the concave is then ready for replacement in the combine or threshing
HWR:lcd - 10 -
CA 02212881 1997-08-12
machine. If on the other hand one wants to assemble a concave having a larger
or smaller grid size, to accommodate a different crop, one removes the concave
from the combine or threshing machine and undoes all of the bolts and nuts used
to attach the cross-bar members and the transverse brace members to the angle
5 brackets. The original third subassemblies are removed and a new set of third
subassemblies in which the longitudinal spacing of the rods 76 is greater or less
than the original spacing therebetween is positioned in contact with the original
cross-bar members and the bolts and nuts are replaced and retightened. Then
the new concave, having the desired grid size, is replaced in the combine or
10 threshing machine so that harvesting of the new crop can commence. Preferablythe farmer will have several sets of third subassemblies available so that a
concave having the desired grid size can be created without substantial
downti me .
From the foregoing it will be seen that by utilizing the kit of
15 components according to the present invention, a farmer can remove, repair (or
rebuild) and reassemble a concave without having to purchase a complete new
unit and that consequently he will enjoy considerable savings in time and
inventory during the harvesting season. He can repair worn cross-bar members,
being able to make use of both longitudinal edges of a cross-bar member,
20 something that cannot be done with existing concaves. He can rebuild a
concave in the field to replace broken components, if necessary, and he can
rebuild a complete concave to create one having a different grid size to
accommodate different crops, something that cannot be done with existing
concaves. Additionally, since the rods do not project through the cross-bars
25 there will be no spearing of the crops and hence no plugging of the equipment.
Clearly, the present invention provides considerable advantages at harvest time
and is a boon to the farmer at that time. It is also clear that the foregoing has
HWR:lcd - 1 1 -
CA 02212881 1997-08-12
described the preferred form of the invention, but that a skilled person in the art
could alter the design of the individual components to accommodate different
makes, models and sizes of combines or threshing machines, but without
departing from the basic principles of the present invention. Accordingly the
5 scope of protection to be afforded this invention is to be determined from the claims appended hereto.
HWR:lcd - 1 2 -
