Patent Abstract:
A system and method for limiting crop loss when harvesting on sloped or rolling ground by adjusting the chaffer and/or sieve, or longitudinal sections thereof, so as to overcompensate for the ground slope so that the chaffer and/or sieve sections are actually inclined away from horizontal opposite the direction of ground slope at a selected angle. Such overcompensation increases crop harvesting efficiencies over systems that simply work to level the chaffer and/or sieve sections, without the high expenses associated with a combine having a pivoting axle.

Full Description:
FIELD OF THE INVENTION 
   The present invention relates agricultural combine harvesting machinery, and more particularly, to an apparatus and method for adjusting the combine cleaning shoe to offset the position of the shoe resulting from operating the combine on a slope. 
   BACKGROUND OF THE INVENTION 
   Combines are large self-propelled vehicles used for harvesting and threshing agricultural crop in a field. A combine operates by cutting or gathering crop standing in a field, and feeding the cut crop to a separator by means of a conveyor mechanism. In the separator, grain is threshed, or beaten from the husk, stems, pods, or cobs, and then the threshed grain is separated from crop material other than grain. After separating, some crop material other than grain is still mixed with the grain. A cleaning system is used to remove the crop material other than grain, sometimes called trash or chaff, from the grain. This is typically done in a device known as a cleaning shoe, which has mechanisms known as a chaffer and a sieve. Typically, the chaffer and sieve are large pans having a flat surface that are oscillated or vibrated to break up the crop material and separate out the grain. The chaffer and sieve can also be a series of adjacent planks that are oscillated or vibrated. The chaffer and sieve can be generally horizontally level from the front to back, or as is commonly seen, arranged to have an upward incline from front to back. In some cleaning systems, a fan is also used to blow the lighter chaff away from the heavier grain material in the chaffer and/or sieve. 
   In operation, the mixed grain and crop material is deposited onto the top front of the chaffer. The lighter weight chaff is separated from the grain by vibration and/or blowing, and the grain and small heavy particles of crop material other than grain fall through louvers in the floor of the chaffer onto the sieve, which is located beneath the chaffer. The sieve oscillates to separate out and break up crop material. The grain, which is heavier than the other crop material, falls through appropriate-size openings in the floor of the sieve, and the cleaned grain from the sieve is carried to the grain tank. 
   Because the cleaning shoe operates by shaking and/or blowing lighter material away from the heavier grain, cleaning shoes tend to work best on flat ground. When the combine is operated on a slope, the crop will tend to build up on the low side of the sieve and chaffer due to gravitational forces. This will result in inefficient cleaning action, with resultant grain loss. 
   While combines with pivoting wheel axles exist for use on land that is predominantly sloped, these hillside combine systems are complex and costly, and of a level of sophistication not needed for operation on generally flat ground or ground having only a mild degree of slope. Instead, one alternative solution for use with limited slope operation is for the level-land combines, as they are sometimes called, to utilize chaffers and sieves made from a plurality of adjacent longitudinal sections separated by dividers. When operating on a slope, material builds up against the dividers, which helps limit the crop build-up to just crop in that particular longitudinal section. However, these devices only reduce crop build-up on the downhill side of the combine, rather than completely eliminating the problem, resulting in cleaning that does not provide maximum grain yield, due to inefficient use of the cleaning shoe. 
   Additionally, some combines utilize systems in which the chaffer and/or sieve, or each longitudinal section thereof is pivotally mounted in a frame such that it can be pivoted or tilted relative to the frame to maintain the device level in relation to the slope of the combine and the ground. Such mechanisms are typically operated by means of an inclinometer and a motor to pivot the sections along their length with respect to the slope of the ground. Other mechanism utilize hanging weights tied into the pivots of the longitudinal sections to tilt the chaffer and/or sieve sections to horizontal and compensate for the slope of the combine. However, even with the use of systems that keep the chaffer or sieve sections horizontal relative to the ground slope, crop processing efficiency is decreased as compared to level-land processing, with efficiency losses depending on factors such as crop conditions and harvesting speed. Therefore, what is needed is a method and apparatus for crop harvesting on rolling or sloped ground that minimizes grain loss typically seen when harvesting on sloped ground, without having to reduce harvesting speed or utilize expensive mechanisms to achieve desired harvest yields. 
   SUMMARY OF THE INVENTION 
   The present invention, accordingly, provides a method limiting crop loss when harvesting on sloped or rolling ground having a limited slope by adjusting the chaffer and/or sieve, or longitudinal sections thereof, so as to overcompensate for the ground slope so that the chaffer and/or sieve sections are actually inclined away from horizontal opposite the direction of ground slope at a selected angle. Such overcompensation has been shown to produce increased crop harvesting efficiencies over systems that simply work to level the chaffer or sieve sections, without the high expenses associated with a hillside combine. 
   The present invention incorporates a system and apparatus for controlling a cleaning shoe having a chaffer and a sieve on a combine when the combine is operating on sloped ground comprising a detecting mechanism for detecting the angle of at least one of the chaffer or the sieve away from horizontal when the combine is operating on sloped ground, a control system for receiving the angle of operation from the detecting mechanism and calculating an angle of operation to improve grain harvesting efficiency, the angle being greater than the angle necessary to return the chaffer or sieve to a horizontal position, and a motor capable of rotating the chaffer or sieve about its longitudinal axis connected to at least one of the combine or sieve, the motor capable of receiving information from the control system to move the chaffer or sieve to the angle calculated by the control system. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic view illustrating a combine having a cleaning shoe in accordance with the present invention; 
       FIG. 2  is a perspective view of a cleaning shoe of the present invention; 
       FIG. 3  is schematic sectional view illustrating a sieve of the present invention when the combine is on a slope; and 
       FIG. 4  is a flow chart showing the steps of the method of the present invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   In the discussion of the FIGURES the same reference numerals will be used throughout to refer to the same or similar components. In the interest of conciseness, various other components known to the art, such as harvesters, storage mechanisms and the like necessary for the operation of the invention, have not been shown or discussed, or are shown in block form. 
   In the following, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be obvious to those skilled in the art that the present invention may be practiced without such specific details. In other instances, well-known elements have been illustrated in schematic or block diagram form in order not to obscure the present invention in unnecessary detail. Additionally, for the most part, details concerning computer software operation and the like have been omitted inasmuch as such details are not considered necessary to obtain a complete understanding of the present invention, and are considered to be within the knowledge of persons of ordinary skill in the relevant art. 
     FIG. 1  shows a combine  10  used for harvesting agricultural crops. The combine  10  comprises a supporting structure  12  having ground engaging wheels  14  extending from the supporting structure  12 . The operation of the combine  10  is controlled from the operator&#39;s cab  15 . A harvesting platform  16  is used for harvesting grain-bearing crop and directing it to a feeder house  18 . The cut crop is directed from the feeder house  18  to a separator mechanism  20  which threshes the grain from the crop material. Once the grain has been threshed and separated, some crop material other than grain is still mixed in with the grain and must be cleaned out, which is done in the cleaning shoe  100 . 
   The cleaning shoe  100  is located downstream from the separator mechanism  20 . The cleaning shoe  100  comprises a chaffer  120  and a sieve  150 . In operation, the grain and chaff mixture is delivered to the front of the chaffer  120  from the separator mechanism  20 . The chaffer  120  is shaken or vibrated so as to move the crop along over the surface of the chaffer  120  toward the rear of the combine  10  in the direction of the arrow. Heavier grain falls through openings in the chaffer  120  onto the sieve  150  below the chaffer  120 . The final cleaning is done in the sieve  150 . In some combines  10 , a fan  102  blows air into or across the cleaning shoe  100  to blow the lighter chaff and straw away from the grain in the chaffer  120 . The sieve  150  is also shaken or oscillated so as to move the crop along over the surface of the sieve  150  toward the rear of the combine  10  in the direction of the arrow shown. In some arrangement of combines  10 , the sieve  150  oscillates with the chaffer  120 , and in other combines  10 , the sieve  150  oscillates in a direction counter to the chaffer  120 . The grain falls through openings in the sieve  150  into the clean grain auger  170 , and is carried from there to the grain tank  180 . 
   As can be seen in  FIG. 2 , the cleaning shoe  100  has a frame  110  to which the chaffer  120 , with the sieve  150  below the chaffer  120 , are mounted or suspended. In many combines  10 , the chaffer  120  is a single unit mounted in a frame having edges  121  along the outside length. In other combines  10 , especially those which are used on sloping ground, the chaffer  120  is divided into a series of two or more longitudinal sections  122  mounted in the frame  121 , extending the length of the chaffer  120  as shown in  FIG. 2 . Similarly, the sieve  150  can also be a single unit mounted in a frame having edges  151  along the outside length, or can have a series of two or more longitudinal sections  152  mounted in and extending the length of the sieve  150 . The chaffer  120  and sieve  150  have a plurality of openings  124 ,  154  contained therein. The position, shape, size and number of openings can be varied to reflect the type of crop being harvested, and the size of the openings  124  in the chaffer  120  is can be different from the size of the openings  154  in the sieve  150 . 
   The present invention is designed to work with both single-surface chaffers and sieves (not shown) and those having a plurality of longitudinal sections  122 ,  152  as shown in  FIG. 2 . Additionally, it has been found that having at least one of the chaffer  120  or sieve  150  containing multiple longitudinal sections  122 ,  152  results in increased efficiency when operating the combine  10  on a slope, and thus is a preferred embodiment. When the chaffer  120  and/or sieve  150  have a plurality of longitudinal sections  122 ,  152 , there are dividers  126 ,  156  between the longitudinal sections. The dividers  126 ,  156  typically form a seal between and along the edge of the adjacent longitudinal section  122 ,  152  to prevent grain and/or crop material from falling through the gaps between the dividers  126 ,  156  and the longitudinal sections  122 ,  152  that are created when the combine  10  utilizing a cleaning shoe  100  of the present invention is operated on a slope and the longitudinal sections  122 ,  152  are tilted at an angle. In operation, the dividers  126 ,  156  work like the outside edges  121 ,  151  and provide a surface against which grain can accumulate when the combine  10  is leaning in that direction when operating on a slope. With dividers  126 ,  156  the grain is compartmentalized, thus limiting the amount of grain that accumulates against the edge  121 ,  151  or any one divider  126 ,  156 , thus improving efficiency of the cleaning shoe  100 . 
   When used with the present invention, the frame of the chaffer  120  and/or sieve  150  is configured with a pivot linkage mechanism to pivot or tilt about the longitudinal axis relative to the combine  10 . For chaffers  120  or sieves  150  having a plurality of longitudinal sections  122 ,  152 , each of the longitudinal sections  122 ,  152  is configured to pivot or tilt about the longitudinal axis relative to the combine  10 . This is achieved by means of pivot pins  130 ,  160  at each end of the chaffer  120  or sieve  150  that provide a pivoting longitudinal axis. However, in some arrangements of the present invention, a single long tube, wire or shaft (not shown) runs down the length of the chaffer  120  or sieve  150 , rather than interconnected pins used on each end. When a chaffer  120  or sieve  150  has multiple longitudinal sections, pins  130 ,  160  are used at the ends of each longitudinal section  122 ,  152  so that each longitudinal section  122 ,  152  can be pivoted. 
   The pins  130 ,  160  are connected to a motor-driven adjusting mechanism  200  that moves the longitudinal sections  122 ,  152  along the longitudinal axis, the mechanism  200  being capable of sufficient control to move the longitudinal sections to various angle for operation. Typically, an electric motor is used with the adjusting mechanism, although it can be appreciated that other types of drive devices, such as a weight-driven or hydraulic control system can be used as well. Additionally, in some arrangements of the present invention, a manual adjusting system can be used in addition to the motor-driven adjusting mechanism to enable the operator to make additional adjustments to the mechanism. 
   As shown in  FIG. 3 , a control system  210  is attached to the motor driven adjusting mechanism  200 , which controls movements of pivot linkage system. The control system  210  can also receive information from the vehicle Electronic Control Unit (ECU)  300  about combine speed, harvesting rates, and other factors that are relevant to operation of this system. In some arrangements of the present invention, only one of the chaffer  120  or sieve  150  is configured to provide for over-compensation, while in other arrangements of the present invention, both the chaffer  120  and sieve  150  are configured to provide for over-compensation. Additionally, in some arrangements of the present invention, an additional sub-control system  210 ′ (not shown) is typically located in the cab  15  of the combine  10 , which the operator can use to receive information from the detector mechanism  220 , and input information to command the motor  200  for manual operation or override of the automated control system  210 . A detector mechanism  220  is attached to at least one longitudinal section  122 ,  152 , or the frame  110 , and is used to detect when the combine  10  is operating on a slope. The detected angle of slope is fed back from the detector mechanism  220  to the control system  210  and/or  210 ′. Based on the information about the operating slope, the control system  210  can determine the ideal over-compensating operating angle A oc , and the control system  210  can send commands to the motor  200  to tilt the longitudinal sections  122 ,  152 , or entire chaffer  120  or sieve  150  to an angle equal to and opposite of the slope of the land plus an angle determined necessary to over-compensate for the slope of the ground, as shown in  FIG. 3 . For an arrangement of the invention having an operator override system, the cab control system  210 ′ can also be used to select a desired operating angle and send commands to the motor  200  as to the preferred over-compensation angle for the longitudinal sections  122 ,  152  or entire chaffer  120  or sieve  150 . 
   The function of the system in operation is represented in  FIG. 4 . The detector mechanism  220  monitors the combine  10  operation and sends signals to the control system  210  on a regular basis. In operation, when the combine  10  is operating at a laterally inclined angle, at step  410 , a signal is sent from the detector mechanism  220  to the control system  210  about the angle of the operating slope. In arrangements of the present invention having an operator override or manual control system  210 ′, the information from the detector mechanism  220  is sent to that control system  210 ′ as well. When at step  412  the control system  210  receives more than a pre-defined number of signals that the combine  10  is operating on greater than a pre-defined level of slope, the over-compensation system of the present invention will be activated. If no, or insufficient slope information, or an insufficient change in slope from the prior slope is detected by the detector mechanism  220 , the present invention will not be activated. 
   At step  420 , the control system  210  will take the information received from the detector mechanism  220  about the operating angle of the combine  10 , and can collect information from the combine ECU  300  about the current operating speed of the combine, and if suitable for the specific arrangement of the invention, other information such as current harvesting rate, type of crop being harvested, tipping ability of the cleaning shoe, and/or numerous other factors, and calculate the preferred over-compensation angle that would improve grain cleaning efficiency. One very simple formula that could be used to calculate the tilt angle A T  needed to over compensate would be to take the current combine operating angle A c,  and multiply it by a specified value V to achieve the tilt angle A T , the amount by which the longitudinal sections  122 ,  152  should be moved to achieve the appropriate over-compensation angle A oc . For example, a standard value for V could be −2. If the combine operating angle A c  is 6°, when it is multiplied by −2, the tilt angle A T  would be −12°. The control system  210  would move the longitudinal sections  122 ,  152  for −12° from the current position in the opposite direction; this would bring the longitudinal sections  122 ,  152  to an over-compensation angle A oc  of −6° from level. Other standard values for V could be used, such as −1.2, −1.5, etc. The standard value used could be varied depending on factors such as the crop type (i.e. corn, soy beans) being harvested. Other more complex formulas using other information and factors, such as those mentioned above, could also be used. It can be appreciated that different formulas can be used to calculate different over-compensation angles for the chaffer and sieve, or the same formula and angle used for both mechanisms. 
   At step  425 , if the system is configured to operate in automatic mode, then at step  440 , the control system  210  sends a signal to the motor  200  to activate the pivot linkage mechanism  140  and move the longitudinal sections  122 ,  152  or complete chaffer  120  and/or sieve  150  to the correct over-compensation angle to improve grain cleaning efficiency. At step  425 , if it is determined that the system is set up to operate in manual/override operation, then at step  430 , the operator can use the override control sub-system  210 ′ to send commands to the motor  200  as to the desired over-compensation operating angle, if different from the calculated over-compensation angle. The operator can have access to the information collected by the control system in  420 , including the calculated angle, for use in specifying an operating angle. 
   The detection mechanism  220  will continue to provide information about the current operating slope to the control system  210 . The control system  210  will compare the inputs received to the previous inputs and determine if there has been a change in the operating slope, and if so, if the change is sufficient to recalculate the preferred overcompensation. In some arrangements of the present invention, the system can be configured to determine if the change in angle has continued for a specified number of inputs before recalculating the over-compensation angle. If so, then at step  420  the control system will calculate a new preferred angle and send the information to the automated control system  210  or the operator&#39;s control system  210 ′ if the system is in manual/override operation if the new preferred angle does not equal the current position angle. 
   In some arrangements of the present invention, each longitudinal section can be positioned at the same over-compensating angle, or each longitudinal section can be adjusted to a different angle so as to appropriately over-compensate and maximize efficiency. For example, the longitudinal section on the furthest downhill side may be tilted at a greater angle than the adjacent or any other uphill longitudinal sections. If the system  210  has determined that for best yield the longitudinal sections  122 ,  152  should be at more than one angle, that information can be sent to the motor  200 . If the system is not operating in automatic mode, the operator can use this information to manually adjust the longitudinal sections  122 ,  152  to the desired angle using the sub-control system  210 ″ in the cab  15 . 
   Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.

Technology Classification (CPC): 0