Separating grate for a grain harvester

• US 4,875,891 A
• Filed: 08/05/1988
• Issued: 10/24/1989
• Est. Priority Date: 03/02/1987
• Status: Expired due to Term

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Wilson, John E., Bennett, Robert E., Peters, Loren W., Turner, Reed J.
• Primary Examiner(s): Hirsch, Paul J.
• Application Number:
  US07/229,784
• Time in Patent Office: 445 Days
• Field of Search: 209/394, 460/108, 460/110, 460/107, 460/109
• US Class Current: 460/110
• CPC Class Codes: A01F 12/24 One-part threshing concaves
• CPC Class Codes: A01F 12/442 Rotary cleaners

Abstract

In an axial flow rotary separator, a separator grate forming part of a generally cylindrical separator casing consists of a series of circumferentially spaced, axially extending, finger bar assemblies. In each finger bar assembly side by side fingers extend circumferentially in the direction of rotation, supported cantilever fashion by an axially extending finger support bar. The fingers and support bar inner surfaces all lie approximately in a cylindrical surface but the radial offset of the free ends of the fingers relative to the following finger support bar, may be chosen or varied according to the crop handled and the grate characteristics desired. In a second embodiment a threshing concave of the same general structure is used in conjunction with a conventional rasp bar threshing cylinder.

Claims

1. In a crop material separator in which a rotor having an axis and direction of rotation about the axis is at least partially wrapped by a concave so as to define a crop material processing zone between the concave and the rotor, the concave having a generally arcuate internal surface and comprising:

an array of circumferentially spaced, axially extending finger bar assemblies, each assembly including a plurality of generally circumferentially downstream extending fingers each having a finger tip and all fingers of a given assembly extending in the same general direction, the finger bar assemblies together defining the generally arcuate internal surface of the concave, and each finger bar assembly lying generally within the arcuate surface, but at least some of the finger bar assemblies being angled with respect to the arcuate surface so that, also with respect to the arcuate surface, the finger tips of the fingers of said some of the finger bar assemblies are radially offset with respect to the opposite ends of said fingers and said fingertips are spaced from the finger bar assembly immediately downstream of it.

2. The concave of claim 1 wherein, in terms of the direction of rotation, said some of the finger bar assemblies are angled inwards relative to the arcuate surface.

3. The concave of claim 2 wherein the angling of said some of the finger bar assemblies relative to the arcuate surface results in a radially outward step between successive finger bar assemblies and further including cover means carried by each finger bar assembly for effectively reducing the amount of the step so that the inner surface of the concave conforms more closely to the overall arcuate surface defined by it.

4. (Twice amended) The concave of claim 1 wherein in terms of the direction of rotation, said some of the finger bar assemblies are angled outwards.

5. The concave of claim 1 wherein the fingers of the at least some of the finger bar assemblies are tangential to the arcuate surface adjacent their upstream ends, so that, in terms of the direction of rotation, there is a step radially inwards from one finger bar assembly to the next.

6. The concave of claim 1 wherein each finger bar assembly includes an axially extending finger support member having an inner surface, substantialy coplanar with the fingers of that assembly and the fingers extend rotationally downstream from the finger support member.

7. The concave of claim 6 wherein the circumferential width of the inner surface of the finger support member is not less than about 1 inch inches.

8. The concave of claim 6 wherein there is a circumferential gap between the downstream tips of the fingers and the finger support member immediately downstream.

9. The concave of claim 6 wherein the downstream tips of the fingers are offset radially from the finger support member immediately downstream.

10. THe concave of claim 6 wherein the fingers are supported cantilever fashion by the finger support member.

11. The concave of claim 10 wherein the fingers are resilient and are deflectable responsive to radially outward loading.

12. The concave of claim 1 wherein there is a circumferential gap between the downstream tips of the fingers and the immediately downstream adjacent finger bar assembly.

13. The concave of claim 1, and further including means for adjusting the angle of the finger bar assemblies relative to the arcuate surface.

14. In a crop material separator in which a rotor having an axis of rotation is at least partially wrapped by a concave having a generally arcuate internal surface so as to define a crop material processing zone between the concave and the rotor, the concave comprising:

an array of circumferentially spaced, axially extending finger bar assemblies each including an axially extending finger support bar, and a plurality of generally circumferentially downstream extending fingers each having a tip and supported cantilever fashion by the support bar and all fingers of a given assembly extending in the same general direction, the finger bar assemblies collectively defining the arcuate concave internal surface and each finger support bar and finger laying approximately within that arcuate surface and the tip of each finger being spaced from the support bar immediately downstream of the respective finger.

15. The concave of claim 14 wherein the fingers are resiliently deflectable outwards with respect to the arcuate surface.

16. The concave of claim 14 wherein at least one of the finger bar assemblies is releasably supported for rotational adjustment about a axis approximately parallel to the axis of rotation of the rotor, so that the angle of inclination of the fingers relative to the arcuate surface may be adjusted.

17. An axial flow rotary separator having a generally cylindrical housing within which an axially extending rotor rotates and propels crop material spirally downstream as an annular mat generally in contact with the housing, the housing including at least one separating grate at least in part axially overlapping the rotor, characterized in that:

the grate comprises a plurality of axially extending finger bar assemblies in each of which a plurality of side by side fingers is supported cantilever fashion and extending rationally downstream, and the finger bar assemblies are disposed so that between the downstream tips of the fingers and the immediately adjacent downstream finger bar assembly, there is a gap of significant circumferential extent and so that all fingers of a given finger bar assembly are substantially coplanar and extend in the downstream direction.

18. The axial flow rotary separator of claim 17 wherein the grate is disposed in a lower portion of the generally cylindrical housing and the rotor is disposed eccentrically downwards towards the grate.

19. The axial flow rotary separator of claim 17 wherein the finger bar assemblies are disposed so that the finger tips of a first assembly are disposed radially inwards relative to an upstream portion of a second finger bar assembly immediately downstream, so as to assist in clearance of material tending to straddle the fingers.

20. The axial flow rotary separator of claim 17 wherein the rotor includes, and relies on for engagement and circumferential propulsion of crop material, generally radially extending finger-like elements which, as the rotor rotates, relatively penetrate and withdraw from the generally annular mat, defining zones of greater and lesser penetration, and wherein the zone of greater penetration at least partially circumferentially overlaps the grate.

21. A threshing and separating combination including a threshing cylinder rotatable about an axis of rotation and an arcuate concave spaced from and at least partially wrapping the cylinder so as to define a threshing and separating zone between them, characterized in that:

the concave comprises an array of axially extending circumferentially spaced finger bar assemblies, defining collectively an internal arcuate surface of the concave and each finger bar assembly including a plurality of circumferentially extending side by side fingers, having in terms of rotor rotation, upstream and downstream ends, and at least one axial support member having an internal surface and lying substantially within the arcuate surface for supporting the fingers, and wherein there is a generally radially extending gap of significant circumferential extent between the downstream end of each finger and the upstream portion of the immediately adjacent finger bar assembly and wherein in all said finger bar assemblies all fingers are substantially coplanar and extend in the downstream direction.

22. The threshing and separating combination of claim 21 wherein the downstream tip of each finger is offset radially outwards with respect to the upstream portion of the succeeding finger bar assembly.

23. The threshing and separating combination of claim 21 wherein the upstream ends of the fingers are each rigidly attached to the axially extending support member, and the the internal surface of the support member is generally coplanar with the fingers.

24. The threshing and separating combination of claim 21 wherein, in the direction of rotation a first finger bar assembly is followed by a second finger bar assembly and wherein the axial spacing of the fingers of the second finger bar assembly establishes a gap between the fingers, and the fingers of the first finger bar assembly are circumferentially aligned approximately with the gaps of the second finger bar assembly.

25. The threshing and separating combination of claim 21 wherein the threshing cylinder is of the rasp-bar type.

26. A harvester crop material separator having a rotor and a grate at least partially wrapping the rotor and cooperating with it to define an arcuate separating zone, characterized in that:

the grate comprises a series of independent finger bar assemblies, axially extending and circumferentially spaced, each assembly including, in terms of rotor rotation, a leading finger support bar and, trailing downstream from each support bar, a plurality of crop carrying fingers ending adjacent the immediately downstream finger support bar, all the fingers included in a given finger bar assembly being substantially coplanar and extending in the downstream direction and the fingers being spaced apart axially so as to define, in cooperation with the finger support bars, between each pair of fingers and associated finger support bars, a separating cell opening permitting separated crop material to pass radially outwards, said cells including, for each finger bar assembly, a pair of end cells and a plurality of intermediate cells, intermediate the end cells, the downstream tips of the fingers being circumferentially spaced from the finger support bar of the immediately downstream adjacent finger bar assembly, so that each intermediate separating cell opening has a pair of laterally directed downstream exits and so that material engaged by the finger support bar may pass laterally along said support bar at said exits.

27. The crop material separator of claim 26 wherein there is a generally radial clearance between the rotor and the grate, and wherein the radial clearance of the finger support bars is about the same as the radial clearance of the fingers.

28. The crop material separator of claim 27 wherein, in each finger bar assembly, the radial clearance of a portion of each finger intermediate its ends is greater than the clearance of the rotationally upstream and downstream ends of the finger bar assembly.

29. The crop material separator of claim 26 wherein the fingers are supported cantilever fashion by the support bars.

30. The crop material separator of claim 29 wherein the downstream tips of at least some of the fingers are offset radially with respect to an adjacent finger support bar.

31. In a crop material separator comprising a rotor and an arcuate grate of the cell type, partially wrapping the rotor so as to define a separating zone between rotor and grate, each of the cells of the grate having a rotationally downstream end and being defined by members of a plurality of respectively axially and circumferentially extending grate elements, said elements having radially inward surfaces, said surfaces together defining an arcuate separating surface, characterized in that:

in a plurality of side-by-side cells of the grate all said cells have a pair of opposite laterally directed exits adjacent their downstream ends so that, in operation, crop material may migrate across at least two cells.

32. The crop material separator of claim 31 wherein the axially extending grate elements are substantially continuous and have rotationally upstream sides and the circumferentially extending grate elements are interrupted adjacent the upstream sides of the axially extending members.

33. A threshing and separating combination including a threshing cylinder rotatable about an axis of rotation and an arcuate concave spaced from and at least partially wrapping the cylinder so as to define a threshing and separating zone between them, characterized in that:

the concave comprises an array of axially extending circumferentially spaced concave bars defining collectively an internal arcuate surface of the concave, each concave bar including an axially extending support member having radially inward surface laying substantially within the arcuate surface and a plurality of circumferentially extending side-by-side teeth carried by and extending rotationally downstream from the support bar, each tooth having a radially inward surface and a downstream tip and wherein there is a generally radially extending gap of significant circumferential extent between the downstream tip of each tooth and the rotationally succeeding support member and wherein the downstream tip of each tooth is offset radially outwards with respect to the inward surface of the rotationally succeeding support member.

34. The threshing and separating combination of claim 33 wherein, in each concave bar, the respective inward surfaces of the support member and of each tooth are substantially coplanar.