AU718667B2 - A lightweight concave having removable grids - Google Patents

Description

Our Ref: 607911 P/00/011 Regulation 3:2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT 9..

S.

9 99 9 99 *6 9 99 9. 9 9.

9 .99 Applicant(s): Address for Service: Invention Title: Deere Company John Deere Road MOLINE Illinois 61265 UNITED STATES OF AMERICA DAVIES COLLISON CAVE Patent Trade Mark Attorneys Level 10, 10 Barrack Street SYDNEY NSW 2000 A lightweight concave having removable grids The following statement is a full description of this invention, including the best method of performing it known to me:- 5020 A LIGHTWEIGHT CONCAVE HAVING REMOVABLE GRIDS BACKGROUND OF THE INVENTION 1. Field of the Invention: The invention is directed to a lightweight concave for a rotary agricultural combine having a bar and wire removable grid that is formed by projection welding.

2. Description of the Prior Art: Agricultural combines are large machines that harvest, thresh, separate and clean an agricultural crop. The resulting clean grain is stored in a grain tank located on the combine. The clean grain can then be transported from the grain tank to a truck, grain cart or other receiving bin by an unloading auger.

There are two basic types of combines: a conventional combine having a transverse threshing cylinder and straw walkers, and a rotary combine having a rotor and rotor casing for threshing and separating the harvested crop. The S" transverse threshing cylinder is mounted in close proximity to a concave. The rotating threshing cylinder in conjunction with the fixed concave threshes the crop material. The concave generally comprises a series of transversely extending bars through which are inserted axially running wires. A concave of this type forms a grate through which the majority of the threshed grain and chaff fall onto a collecting assembly where it is directed to the cleaning system of the combine.

U.S. Patent 4,909,772 illustrates such a concave. U.S. Patent 5,024,631 discloses a conventional transverse threshing concave having a frame on which 25 are mounted three removable sieve lining sections.

Rotary combines are provided with an infeed section for pulling crop material into the rotary crop processing assembly from the feederhouse, a threshing section for threshing the crop material, and a separating section for separating the grain from the threshed crop material. The rotary crop processing unit comprises a rotor that is surrounded by a casing. The bottom of the casing is provided with a series of grates through which the grain and chaff fall from the casing. The grates located beneath the threshing section of the rotary crop processing unit comprises a concave, such a concave is disclosed in U.S. Patent P:\WPDOCS\DYS\SPECIE\6079 I.SPE 1/2/00 -2- 4,499,908. In this patent one side of the concave is pivotally mounted to the crop processing unit and the other side is adjustably mounted to the crop processing unit to control the clearance between the concave and rotor. U.S. Patents 4,192,322 and 4,422,463 spiral wire concave in which a spiral wire is welded to a series of axially extending spacer bars.

Projection welding is a form a resistance welding wherein the heat for the welding is derived from the localisation of electrical resistance at predetermined points by means of projections. The projections maybe made of stamping or machining.

SUMMARY

It is an object of the present invention to provide a lightweight concave for the threshing section of a rotary combine having easily removable grids.

According to one aspect of the present invention there is provided a lightweight fl concave for the threshing section of a rotary combine, the concave comprising: a frame having at least two longitudinally extending curved members that are coupled to one another by two laterally extending members, the frame is provided with a first mounting assembly; and at least one easily removable grid being releasably mounted to the frame by the first mounting assembly engaging the grid, the grid is provided with a plurality of longitudinally o extending curved rods and a plurality of laterally extending straight bars, the straight bars are S: i provided with an outer surface, at least one of the rods and the straight bars are provided with projections and are projection welded to one another.

Preferred embodiments of the invention will be hereinbefore described with reference to the accompanying drawings.

Figure 1 is a semi-schematic side elevation of a self propelled combine having a rotary 0 processing unit.

P:\WPDOCS\DYS\SPECIE\60791 I.SPE 1/2/00 -3- Figure 2 is an enlarged side view of the pivotal connection of the concave frame.

Figure 3 is an exploded side view of the concave frame and grid.

Figure 4 is a top view of the concave.

Figure 5 is a sectional view taken along line 5--5 of the concave.

DETAILED DESCRIPTION Fig. 1 shows an agricultural combine 10 comprising a supporting structure 12 having ground engaging means 14 extending from the supporting structure. A harvesting platform 16 is used for harvesting a crop and directing it to a feederhouse 18. The harvested crop is directed by the feederhouse 18 to a beater 20. The beater directs the crop upwardly through the inlet transition section 22 to the rotary crop processing unit 24. A rock trap 25 is positioned between the feederhouse and the beater 6 p :The rotary crop processing unit 24 threshes and separates the harvested crop material.

It comprises a rotor 26 and a casing 28 that define an inlet section 30, a threshing section 32 and a separating section 34. The bottom of the casing is provided with a concave 36 under the threshing section 32 and a separating grate 38 under the separating section 34.

Grain and chaff falling through the concave 36 and the separating grate 38 are directed to cleaning system 40. The cleaning system 40 removes the chaff and directs the clean grain to a clean grain elevator (not shown). The clean grain elevator deposits the clean grain in a grain tank 42. The clean grain in the tank 42 can be unloaded into a grain cart or truck by an unloading auger 44.

The present invention is directed to the concave 36 located under the threshing section 32 of the rotary crop processing unit 24. The present invention could be used as a separating P:\WPDOCS\DYS\SPECIE\60791.SPE 1/2/00 -4grate. However in the preferred embodiment the separating grate is a comb separating grate similar to the one disclosed in U.S. Patent 4,875,891, which is incorporated herein by reference.

Threshed and separated straw is discharged from the rotary crop processing unit 24 through outlet 46 to a discharge beater (not shown). The discharge beater in turn propels the straw out the rear of the combine. The operation of the combine is controlled from operator's cab 48.

The rotor 26 comprises a hollow cylindrical drum having a plurality of crop processing elements which are used to engage the crop and rotate it in the casing 28. A series of helical elements (not shown) located in the casing housing index the crop rearwardly.

Three concave sections form concave 36. Each section comprises a frame 49 having three curved longitudinally extending members 50, 52 and 54. These curved longitudinally extending members arejoined at their ends by laterally extending members 56 and 58. The two -6 outside longitudinally extending members 50 and 54 are provided with a curved rim 60 along o 5 their inside surfaces 62. The outside longitudinally extending members 50 and 54 are also provided with six ears 64 which are welded to the inside surface 62. The ears 64 are provided with mounting bolts 66, mounting nuts 68 and mounting washers The concave grid 72 of the present invention comprises a plurality of longitudinally 0*e extending rectangular bar stock 74 to which is projection welded longitudinally extending wirelike rods 76. The grid is projection welded by first mounting the rectangular bar stock 74 in a fixture so that it is arranged in a curved manner as disclosed in Figure 3. The bar stock 74 is provided with a series of projections for receiving the laterally extending curved wire-like rods 76. The wire rods and bar stock are coupled to a source of electric power. As electric power is switched on it forms a current between the bar stock. Electrical resistance is highest at the projections. As resistance increases, the projections become heated and weld the rods 76 to the bar stock 74.

P:\WPDOCS\DYS\SPECIE\60791 I.SPE 1/2/00 The grid is mounted to the frame by first inserting it into trapping lip 80. Trapping lip is located on laterally extending member 58. The lip 80 entraps the grid between the lip and the rims 60. The remaining grid is then held in place by the mounting bolts 66 and washers clamping the grid against the rims Laterally extending member 56 is provided with a pivotal bolt connection 84 so that the concave 36 can be pivotally coupled to the rotary crop processing unit 24. Laterally extending member 58 is provided with a clearance connector 86 comprising an aperture for receiving a concave clearance adjustment bolt (not shown) for adjusting the clearance of the concave relative to the rotor.

The present invention provides a lightweight concave grid that. can be easily manufactured, is durable and easily replaceable. As such the invention should not be limited by the above described embodiment, but should be limited solely by the claims that follow.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" or "comprising" will be S. understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

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Claims (8)

1. A lightweight concave for the threshing section of a rotary combine, the concave comprising: a frame having at least two longitudinally extending curved members that are coupled to one another by two laterally extending members, the frame is provided with a first mounting assembly; and at least one easily removable grid being releasably mounted to the frame by the first mounting assembly engaging the grid, the grid is provided with a plurality of longitudinally extending curved rods and a plurality of laterally extending straight bars, the straight bars are provided with an outer surface, at least one of the rods and the straight bars are provided with projections and are projection welded to one another.

2. A concave as defined by claim 1 wherein the first mounting assembly comprises more than two ears that are attached to the longitudinally extending curved members, the ears are provided with mounting apertures, mounting bolts and mounting washers for mounting the grid S to the frame. 99 9 d-o

3. A concave as defined by claim 2 wherein at least two of the curved longitudinally extending members are provided with a curved rim which contacts the laterally extending straight bars when the grid is mounted to the frame. 0

4. A concave as defined by claim 3 wherein at least one of the laterally extending members a 0*•of the frame is provided with a trapping lip for trapping the grid between the lip and the rims. 9 0* 000

5. A concave as defined by claim 4 wherein the frame is provided with a second mounting assembly for releasably mounting the concave to a combine.

6. A concave as defined by claim 5 wherein the second mounting assembly comprises a A30 pivotal connection for pivotally mounting the concave to the rotary crop processing unit. P:\WPD0CS\DYS\SPECIE\6791 I SPE 112100 -7-

7. A concave as defined by claim 6 wherein the second mounting assembly further comprises a clearance adjustment connection for mounting the concave to the rotary crop processing unit.

8. A concave substantially as hereinbefore described with reference to the accompanying drawings. Dated this 3 1st day of January, 2000 DEERE COMPANY By Its Patent Attorneys DAVIES COLLISOIN CAVE