Linkage for agricultural harvester cleaner

1. A sieve assembly for an agricultural harvester, said sieve assembly comprising:

a sieve surface supported between a right frame and a left frame that are interconnected by at least one cross frame;

first supports for one of a forward end and a rear end of said right and left frames, said supports comprising first and second members having triangularly positioned mounting points, said first and second members being interconnected at two of said mounting points, said third mounting point on said first member being pivotally mounted to an end frame support for said sieve, and said third mounting point for said second member being pivotally mounted to said right and left frames for driving fore and aft movement and permitting side to side movement; and

second frame supports for said right and left frames at said end opposite said first and second members, permitting fore and aft movement and side to side movement;

wherein said second member is connected to said right and left frames at said cross frame.

2. The sieve assembly as claimed in claim 1 , further comprising rubber bushings interconnecting said first and second members at least at the two mounting points mutually interconnecting the frames.

3. The sieve assembly as claimed in claim 1 , wherein said first and second members are at least partially formed from legs of a triangle interconnecting said triangular mounting points.

4. The sieve assembly as claimed in claim 3 , wherein said first and second members are cast.

5. The assembly sieve as claimed in claim 3 , wherein said first member has a further support point for driving a mechanism for reciprocating movement.

6. The sieve assembly as claimed in claim 5 , wherein said further support comprises legs of a triangle.

7. The sieve assembly as claimed in claim 1 , wherein the common mounting points for said first and second members are forward of said third mounting points.

8. A sieve assembly for an agricultural harvester, said sieve comprising:

a right frame and a left frame interconnected by at least one cross frame;

first supports for one of a forward end and a rear end of said right and left frames, said first supports comprising first and second members having triangularly positioned mounting points, the first and second members being interconnected at two of the mounting points, the third mounting point on said first member being pivotally mounted to a support for said sieve, and the third mounting point for said second member being pivotally mounted to said right and left frames for driving fore and aft movement and permitting side to side movement; and,

second supports for said right and left frames at the end opposite the first and second members, permitting fore and aft movement and side to side movement;

wherein said first and second members are at least partially formed from legs of a triangle interconnecting said triangular mounting points

wherein said first and second members are cast;

wherein said second member has integral structural webs reinforcing said triangular legs.

9. An agricultural harvester comprising:

a chassis;

grain processing equipment mounted in said chassis and including a main sieve for movement of chaff to a discharge end;

a sieve comprising a right frame and a left frame interconnected by at least one cross frame;

first supports for one of a forward end and a rear end of said right and left frames, said supports comprising first and second members having triangularly positioned mounting points, said first and second members being interconnected at two of said mounting points, said third mounting point on said first member being pivotally mounted to a support for said sieve, and said third mounting point for said second frame being pivotally mounted to said right and left frames for driving fore and aft movement and permitting side to side movement; and

second supports for said right and left frames at said end opposite said first and second members, permitting fore and aft movement and side to side movement;

wherein said first and second members are pivotally connected to said chassis at one of said common interconnection points between said first and second member for pivotal motion with respect to the chassis.

10. The agricultural harvester as claimed in claim 9 , further comprising a mechanism supported by said chassis for driving the first member of said supports into fore and aft oscillation.

11. The agricultural harvester as claimed in claim 10 , wherein said oscillating mechanism comprises a link connected to said third mounting point on said first member and an eccentric mechanism for driving said link in a fore and aft direction.

12. The agricultural harvester as claimed in claim 9 , wherein said common interconnection points between said members are forward of said first of said third mounting points with respect to a direction of the flow of crop material over said sieve.

13. The agricultural harvester as claimed in claim 12 , wherein said common point mounting points are upper and lower points, said pivotal mounting to said chassis is at the upper mounting point.

14. The agricultural harvester as claimed in claim 9 , wherein said first and second members are formed from legs of a triangle, said legs interconnecting said triangularly positioned mounting points.

15. The agricultural harvester as claimed in claim 14 , wherein said first and second members are cast.

16. The agricultural harvester as claimed in claim 15 , wherein said second member has integral webs reinforcing said legs.