Harvester sieve opening indicator

Abstract: Adjustable sieve means (31) are provided for an agricultural harvesting machine (1) comprising louvres (41) positioned behind one another and being movable through a range of positions between a fully closed and a fully opened position; consecutive louvres defining an opening (d) inbetween when in an opened position; adjustment means (47) for changing said opening (d); and opening indicator means (48), including a movable part (65), which is unitarily moved with one of said louvres (41), when said opening (d) is adjusted. These indicator means (48) permit the verification of the sieve opening (d), even when the louvres are not accessible for measurement with gauges, and a direct link between the louvres (41) and the movable part (65) avoids the inaccuracies which are conceivable when the indicator means (48) is sensing the movement of further, intermediate components of the adjustment means (47).

Description: The present invention relates to agricultural harvesting machines such as combine harvesters, and more particularly to the adjustable grain sieves thereof. The invention is particularly advantageous when on the one hand access to one of this sieves is limited in such way that direct verification of the actual sieve opening is hindered and on the other hand when a precise sieve setting is required for obtaining an efficient grain cleaning. Combine harvesters have been developed for efficient harvesting of a wide range of crops. To this end a variety of machine settings can be changed and adjusted. These include the setting of the louvres of the upper and lower sieves. The opening inbetween these louvres has to be adapted to the grain type in order to obtain an efficient separation of grain on the one hand and chaff and straw on the other hand. Especially the opening of the lower sieve has to be adjusted to a precise sieve setting in order to meet optimum grain cleaning requirements. Sieves enabling such adjustments have already been described in US-A-2.253.296. Usually the opening of the upper sieve is verified by the insertion of calibrated means such as gauges inbetween the louvres at the rear of the sieve. The surface of the upper sieve mostly is readily accessible for such measurement. The lower sieve however is not as easily accessible because of its hidden position under said upper sieve. Access to the louvres of the lower sieve can further be hindered by extensions connected to the rear of the upper sieve, such as a rake or a sensor plate for a grain loss indicator. The use of calibrated means for the verification of this opening thus is rendered unpractical. Several methods have been thought of to by-pass this problem. On sieves with an adjustment handle which is locked into a toothed segment, it is a common practice to count the number of teeth that lay between a leftmost position, in which the louvres are closed, and the actual position of the handle. But this is not an accurate measurement of the sieve opening, because the leftmost position is not corresponding to the same tooth on every sieve and the opening determined by one tooth is not necessarily corresponding to a step of e.g. exactly one millimetre. Further inaccuracies occur because of the tolerances on the dimensions of the intermediate adjustment links and handles, because of the play of these components relative to each other and because of the possible deformation thereof during operation. The German Utility Model DE-U-69.05.754 is showing a graduated scale applied to an adjustment member of the sieve opening. Other types of sieve opening indicators on adjustment means can be found in US-A-3.472.378. These indicators may give an opening read-out in millimetres or fractions of an inch, but the zero position which corresponds to fully closed sieve louvres, is not indicated. Neither do these systems cope with the inaccuracies caused by the tolerances, play and deformation of the adjustment means intermediate the adjustment member and the louvres. DE-U-91.12.209 discloses the use of potentiometers for providing information on the sieve opening to the operator of the combine harvester. The sieve opening is controlled by an electrical motor wich acts on the louvres via Bowden cables and levers. Herein, the rotors of the potentiometers are linked to the motor end of the Bowden cables. The signal provided by the potentiometers shows important inaccuracies because of the relative elasticity of the cables and the play in the lever system. Hence the signal may deviate substantially from the actual sieve opening. Accordingly, it is an object of the present invention to overcome the aforementioned problems of louvre opening measurement in a simple, though nevertheless efficacious manner. According to the present invention an adjustable sieve means for an agricultural harvesting machine is provided which comprises: louvres positioned behind one another and being movable through a range of positions between a fully closed and a fully opened position; consecutive louvres defining an opening inbetween when in an opened position; adjustment means for changing said opening and opening indicator means including a movable part. This sieve means is characterized in that said movable part and at least one of said louvres are unitarily moved, when said opening (d) is adjusted. Preferably said movable part is moved by the support means to which the louvre is affixed. The actual opening may be displayed in length units on a graduated scale. For better visibility this graduated scale may be provided upon said movable part and a horizontal edge of a stationary part may serve as a reference point for reading out the actual sieve opening. For ease of control of said opening, the opening indicator means may be installed adjacent to the sieve adjustment means, such as an adjustment handle. An agricultural harvesting machine embodying 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 schematic elevational view lengthwise of a combine harvester; Figure 2 shows a lower sieve of the sieve means shown in Figure 1; Figure 3 illustrates to a larger scale a part of the rear portion of the sieve of Figure 1 in which portions have been removed for better visibility; Figure 4 shows a partial sectional view taken along the lines IV-IV in Figure 3; Figure 5 shows a partial sectional view taken along the lines V-V in Figure 4; Figure 6 shows a partial rear view taken along the lines VI-VI in Figure 6; Figure 7 is illustrating an indicator means according to an alternative embodiment of the invention; The terms "forward", "left", "right", "rear", etc. used in connection with the agricultural harvesting machine and/or components thereof are determined with reference to the direction of forward operative travel, but should not be considered as limiting. Also, the terms "grain", "straw" and "tailings" are used principally throughout this specification for convenience and it should be understood that these terms equally 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 ears are referred to as "tailings". Although the combine harvester illustrated in Figure 1 is of conventional design, employing straw walkers, it readily will be appreciated that the invention is equally applicable to the so-called rotary combines such as the axial flow type combines. For ease of reference, a brief general description of the combine harvester shown in Figure 1 will be given. This combine harvester, generally indicated at 1, comprises a main chassis or frame 2 supported on a front pair of drive wheels 3 and a rear pair of steerable wheels 4. Supported on the main chassis 2 are an operator's platform 5, with operator's cab 6, a grain tank 7, a threshing and separating mechanism 8, a grain cleaning mechanism 9 and a power plant or engine 10. A conventional header 11 and straw elevator 12 extend forwardly of the main chassis 2 for generally vertical movement which is controlled by extensible hydraulic cylinders 13. As the combine harvester 1 is propelled forwardly over a field with standing crop, the latter is severed from the stubble by a sickle bar at the front of the header 11, whereafter the header 11 and the straw elevator 12 supply the cut crop to the threshing and separating mechanism 8. The crop received therein is threshed and separated, that is to say, the crop is rubbed and beaten, whereby the grain, seed or the like, is loosened and separated from the straw, coils or other discardable part of the crop. The combine harvester illustrated in Figure 1 comprises a conventional threshing mechanism including a threshing cylinder 14, a straw beater 16 and a separator rotor 18. Conventional straw walkers 20 are operable, in use, to discharge a layer of remaining crop material (i.e. mainly straw as the grain is separated therefrom) through the straw hood 21. Grain which has been separated by the threshing and separating mechanism 8 falls onto a first grain pan 24 of the cleaning mechanism 9 which further also comprises a pre-cleaning sieve 26, positioned above a second grain pan 27, a pair of sieves 30, 31, disposed the one above the other, and a cleaning fan 25. The grain pans 24, 27 and the sieves 26, 30 31 are oscillated generally back-and-forth for transporting threshed and separated grain from the first grain pan 24 to the pre-cleaning sieve 26 and second grain pan 27 and therefrom to the sieves 30, 31. The same oscillatory movement spreads said grain across said sieves 26, 30, 31, while permitting the passage of cleaned grain by gravity through these sieves 26, 30, 31. The grain on the sieves 26, 30, 31 is subjected to a cleaning action by the fan 25 which provides an air flow through said sieves 26, 30, 31 to remove chaff and other impurities such as dust from the grain by making this material airborne for discharge from the machine through the outlet 22 of the straw hood 21. Clean grain eventually falls to a clean grain auger 32 in a clean grain auger trough 33 and is subsequently transferred therefrom to the grain tank 7. Tailings eventually fall to a tailings auger (not shown) in a tailings auger trough 35. The tailings are transported by said tailings auger to a separate rethresher 34 and returned to the cleaning mechanism 9 for repeated cleaning action. All components described so far are conventional in the art, and therefore no further detailed description thereof is deemed necessary. Referring now to Figure 2, a lower sieve 31 according to the present invention will be described in further detail. This sieve 31 comprises a plurality of louvre sets 40, 40', 40'', mounted in a sieve frame 42. It further comprises sieve adjustment means 47 and indicator means 48. Each louvre set 40, 40', 40'' is formed by a series of adjustable louvres 41, which are positioned the one behind the other. The sieve frame 42 comprises a rear frame member 43, side frame members 44, 44', a front frame member 46 and intermediate frame members 45, 45', the latter being provided inbetween said side frame members 44, 44' and extending parallel therewith. As illustrated in Figures 3 and 4 the louvres 41 are attached to mounting rods 49, which are pivotably mounted in holes in the side frame members 44, 44' and intermediate frame members 45, 45'. Adjacent to the intermediate frame member 45 these mounting rods 49 are provided with a cranked extension 50, the position of which can be changed by the sieve adjustment means 47, whereby the rods 49 are pivoted around their respective axes of rotation defined by the mounting holes in the said frame members 44, 44', 45, 45'. The pivotal movement of said rods 49 rotates the attached louvres 41 concurrently and changes the sieve opening in between two adjacent louvres 41 as defined by distance d depicted in Figure 4. The position of the cranked extensions 50 is controlled by the slots in an adjustment slat 51, which is connected through a link member 52 to an adjustment handle 55. This adjustment handle 55 is pivotably attached at a pivot 54 to the intermediate frame member 45 and is locked in position by means of a locking handle 56 intermeshing with a toothed segment 57, which is welded to the rear frame member 43. This locking handle 56 is pivotably attached to the adjustment handle 55 at a second pivot 60 and held in mesh with the toothed segment 57 by a spring 58. For adjusting the sieve opening d the said locking handle 56 is pushed towards adjustment handle 55, thus releasing it from the toothed segment 57, and the adjustment handle 55 is turned about pivot 54 in the one or other direction. Accordingly, the link member 52, which is connected to the adjustment handle 55 through an eccentric link 53, is pushed forward or backward, which movement is transferred upon the adjustment slat 51. The action of the adjustment slat 51 on the cranked extensions 50 urges the rear ends of the louvres 41 to raise when said adjustment slat 51 is moved to the rear of the combine harvester 1 and urges the same to lower when said slat 51 is moved to the front, respectively increasing or decreasing the sieve opening d. As illustrated in Figures 3 to 5, an indicator member 65 with a slot 66 is installed over part of the cranked extension 50 of one of the mounting rods 49, between the intermediate frame member 45 and the adjustment slat 51. The cross-section of the slot 66 and of the cranked extension 50 are such that the latter closely fits within the former, whereby the indicator member 65 is moved in a unitary manner with the corresponding mounting rod 49 and thus with the louvre 41 attached thereto. The said louvre 41 and the indicator member 65 are thus directly linked and, when the sieve opening d is adjusted, their movements are identical: the louvre 41 and the indicator member 65 are both pivoted about the same angle. The indicator member 65 comprises an arm 69 which extends substantially towards the rear of the sieve 31. The rear end of the arm 69 is provided with an arcuate surface. The circular cross-section thereof makes this surface remain at a constant distance from the rear frame member 43, when the sieve opening d is adjusted and the indicator member 65 is pivoted accordingly. As best seen in Figure 6, a graduated scale 67 is provided on the said arcuate surface of indicator member 65. Proximate to this surface a reference plate 68 is welded to the rear frame member 43, the top edge of which plate 68 indicates the sieve opening d on said graduate scale 67. The relative position of the calibrations thereof on the indicator member 65 is such that the zero position, which can be determined with reference to said top edge, corresponds to fully closed louvres 41, whereas a scale reading above zero corresponds to the actual sieve opening d, expressed in millimetres. Alternatively this sieve opening d may be expressed in any other suitable length unit, such as fractions of an inch. In Figure 7 an alternative embodiment of the sieve opening indicator means 48 is shown. Comparable to the first embodiment an indicator member 75, which is installed between the intermediate frame member 45 and the adjustment slat 51, comprises a slot 66', which closely fits over the cranked extension 50 of one of the mounting rods 49. The movement of this indicator member 75 is thus equal to the movement of the indicator member 65 illustrated in Figures 3 to 6. The rear part of said indicator member 75, ending in a pointer 76, lies adjacent to the rear portion of intermediate frame member 45, which takes the form of an arcuately shaped sector 78. On this sector 78, a graduated scale 77 is provided along the path of the pointer 76, which indicates the actual sieve opening d in millimetres or eventually any other suitable length unit, on the said scale 77. The graduated scale 77 is formed by a series of notches 79 in the sector 78. In both embodiments the opening indicator means 48, comprising the indicator member 65, respectively 75, and reference plate 68, respectively 78, lay adjacent to the sieve adjustment means 47, in such way that a person who is standing at the rear of the sieve 31 and operating the adjustment means 47 to change the sieve opening d, has a direct view on the graduated scale 67, respectively 77. Thus the operator can immediately verify the resulting opening d during the adjustment thereof, without having to move to another location. In this manner, the relative position of indicator means 48 and adjustment means 47 enables a swift and precise sieve setting. The opening indicator means 48 of the foregoing embodiments eliminate the need for further verification of the sieve opening d with gauges in the unaccessible area under the upper sieve 30. Tolerances, play and deformation of the components of the adjustment means 47 will not affect the accuracy of the indicator reading because the movement of the indicator member 65 is unitarily linked to the movement of the mounting rod 49 and the louvres 41 attached to it. Still other alternative embodiments of the opening indicator means of Figures 3 to 7 are conceivable: for example an indicator member may be attached to a mounting rod or directly to a louvre by way of welding, gluing or any other suitable method. In all cases the indicator member will move in unison with the louvre to which it corresponds. Also the manual sieve adjustment means 47 as described above may be replaced by adjustment means which use electrical, hydraulic or pneumatic actuators to change the position of the adjustment slat 51. In all cases remote control of such adjustment means can be envisaged.

Claims: Adjustable sieve means (31) for an agricultural harvesting machine (1) comprising: louvres (41) positioned behind one another and being movable through a range of positions between a fully closed and a fully opened position; consecutive louvres defining an opening (d) inbetween when in an opened position; adjustment means (47) for changing said opening (d); and opening indicator means (48), including a movable part (65/75), characterized in that: the movement of said movable part (65/75) is identical to the movement of at least one of said louvres (41), when said opening (d) is adjusted. Adjustable sieve means according to claim 1, characterized in that the movement of said movable part (65/75) is directly linked to the movement of said at least one louvre (41). Adjustable sieve means according to claim 1 or 2, characterized in that said at least one louvre (41) and said movable part (65/75) are pivotable about a common axis. Adjustable sieve means according to any of the preceding claims, characterized in that said at least one louvre (41) is affixed to a rod shaped, movable support (49), the movement of which is transferred onto said movable part (65/75). Adjustable sieve means according to any of the preceding claims, characterized in that the indicator means (48) display the said opening (d) on a graduated scale (67/77). Adjustable sieve means according to claim 5, characterized in that said opening (d) is displayed in length units on said graduated scale (67/77). Adjustable sieve means according to claim 5 or 6, characterized in that said graduated scale (67) is provided upon said movable part (65). Adjustable sieve means according to any of the preceding claims, characterized in that said opening indicator means (48) further includes a stationary part (68/45) which is fixedly attached to a frame (42), operably supporting the louvres (41). Adjustable sieve means according to claim 8 when appended to claim 7, characterized in that said graduated scale (67) is provided upon an arcuate surface of said movable part (65), which surface passes in a substantially vertical direction in front of a substantially horizontal edge of said stationary part (68), when said opening (d) is adjusted; said horizontal edge serving as a reference point for reading out the actual sieve opening (d) on said graduated scale (67). Adjustable sieve means according to claim 8 when appended to claim 5 or 6, characterized in that said graduated scale (77) is placed upon said stationary part (45). Adjustable sieve means according to claim 5 or 10, characterized in that said graduated scale (77) is formed by a series of notches (79). Adjustable sieve means according to any of the preceding claims, characterized in that said indicator means (48) is installed adjacent to said adjustment means (47).

Inventors: HOLLEVOET WILLY C, JONCKHEERE MARC R M, HOLLEVOET, WILLY C., JONCKHEERE, MARC R.M.
Applicants: FORD NEW HOLLAND NV, NEW HOLLAND BELGIUM N.V.
Application year: 1993
Main classification: A01F12
IPC codes: A01F12