Abstract:
An apparatus and method for varying the speed of a reel versus ground speed of an agricultural windrower, wherein a programmable control module in connection with a signal operated device operable for controlling operation of the reel, is programmed to operate in an automatic mode to control the reel speed as a percentage of the ground speed, while preventing the reel speed from falling below a minimum value.

Description:
[0001]     This application claims the benefit of U.S. Provisional Application Nos. 60/699,610, and 60/699,489, filed Jul. 15, 2005. 
     
    
     TECHNICAL FIELD  
       [0002]     U.S. Pat. No. 6,901,729, is incorporated herein by reference in its entirety. This patent describes a header flotation system that is referred to as “non-independent”. Provisional Application Nos. 60/699,610, and 60/699,489, filed Jul. 15, 2005, are also incorporated herein by reference in their entirety.  
       BACKGROUND OF THE INVENTION  
       [0003]     The present invention relates to agricultural windrowers and, more particularly, to apparatus and a method for varying reel speed versus ground speed for accommodating different or changing conditions, such as different crop conditions.  
         [0004]     A windrower typically consists of a self-propelled tractor or similar vehicle, and a cutting mechanism which is either towed by the tractor or carried thereby. The cutting mechanism carried by a windrower is typically referred to as a header, and is supported on the windrower by forwardly projecting arms. Briefly, the arms comprise elements of a lift and flotation mechanism or mechanisms operable for setting a height of the header above the ground or other surface over which the windrower moves, the flotation permitting the header to ride lightly up and over rises in the terrain during field operation.  
         [0005]     Headers are typically available in a variety of configurations. Common elements of different headers include cutters operable for severing crops from the field. One typical cutting mechanism is a sickle cutter which includes a row of knives which extend across the width of the header and which are powered to move reciprocally sidewardly relative to a sidewardly extending array of fixed knives or bars, thereby effecting a cutting action. It is typically desirable for the cutters to operate at a constant speed, but, in operation, the cutting speed may vary as a result of changing conditions such as crop population, contact with the ground, or the like.  
         [0006]     The sickle cutters may be accompanied by a reel disposed thereabove and rotatable for engaging the crop before cutting or other treatment, as is well-known in the art. It is of value to have a capability of varying the rotational speed of the reel versus ground speed to accommodate changing and different conditions, particularly crop conditions. In this regard, it is well-known to provide a capability for an operator to dial in a speed in revolutions per minute (rpm) using a speed selector dial, and for the reel to be rotated at the selected speed. A windrower may have the capability to be used with any of several headers, and the power required for driving the reel of a particular header at a selected speed may differ from that required for driving the reel of a different header.  
         [0007]     A reel can be driven using a fluid drive, such as a fluid power takeoff (PTO), or a dedicated reel drive, of a windrower. A pump driven by the engine of the tractor provides pressurized fluid to the PTO system. The pump can be of a fixed displacement, the speed and direction of operation of the reel being controlled by one or more proportional solenoid controlled valves. Varying electrical current signals would be utilized for operating the solenoids, for rotating the reel at the desired speed and in the desired direction, and the electrical current required for driving the reel at a selected speed would need to be known, such that the controller controlling the solenoids can apply the correct current responsive to an operator command for achieving a selected speed. Reel speed will typically fall within a range between about 100% of the ground speed of the windrower, and 130 to 140% thereof.  
         [0008]     It would be desirable to have an apparatus and method which enables varying the reel speed versus ground speed, particularly for varying reel speed within the range set forth above of between about 100% and 130 to 140% of ground speed. Additionally, it would be desirable to have an apparatus and method automatically operable for maintaining the reel speed at a selected percentage of ground speed during operation wherein the ground speed is varying. Further, it would be desirable to have an apparatus and method for automatically controlling reel speed, wherein the reel speed is not allowed to fall below a minimum value, even though the ground speed is decreased significantly, for instance, when the windrower is being slowed significantly for turning, or the like, such that when a stand of crop is contacted by the reel, the reel will not be moving so slow as to tend to push the crop away from the header.  
       SUMMARY OF THE DISCLOSURE  
       [0009]     What is disclosed is an apparatus and method which enables selectably varying the reel speed versus ground speed, particularly for varying reel speed within the range set forth above of between about 100% and 130 to 140% of ground speed, and automatically maintaining the reel speed at the selected percentage of the ground speed as the ground is varied, but which will prevent the reel speed from falling below a certain value. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     The advantages of this invention will be apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein:  
         [0011]      FIG. 1  is a side elevational view of a crop harvesting machine of the type with which the invention may be used, showing a header including a reel in connection with apparatus of the instant invention;  
         [0012]      FIG. 2  is a schematic of a reel driveline of the machine of  FIG. 1 ;  
         [0013]      FIG. 3  is a written listing of steps of the preferred program of the invention;  
         [0014]      FIG. 4  is a written listing of further steps of the preferred program of the invention;  
         [0015]      FIG. 5  is a written listing of still further steps of the preferred program of the invention;  
         [0016]      FIG. 6  is a written listing of still further steps of the preferred program of the invention; and  
         [0017]      FIG. 7  is a written listing of still further steps of the preferred program of the invention;  
         [0018]      FIG. 8  is a written listing of still further steps of the preferred program of the invention;  
         [0019]      FIG. 9  is a written listing of still further steps of the preferred program of the invention;  
         [0020]      FIG. 10  is a written listing of still further steps of the preferred program of the invention;  
         [0021]      FIG. 11  is a written listing of still further steps of the preferred program of the invention;  
         [0022]      FIG. 12  is a written listing of still further steps of the preferred program of the invention;  
         [0023]      FIG. 13  is a written listing of still further steps of the preferred program of the invention;  
         [0024]      FIG. 14  is a written listing of still further steps of the preferred program of the invention;  
         [0025]      FIG. 15  is a written listing of still further steps of the preferred program of the invention;  
         [0026]      FIG. 16  is a written listing of still further steps of the preferred program of the invention;  
         [0027]      FIG. 17  is a written listing of still further steps of the preferred program of the invention;  
         [0028]      FIG. 18  is a written listing of still further steps of the preferred program of the invention;  
         [0029]      FIG. 19  is a written listing of still further steps of the preferred program of the invention;  
         [0030]      FIG. 20  is a written listing of still further steps of the preferred program of the invention;  
         [0031]      FIG. 21  is a written listing of still further steps of the preferred program of the invention;  
         [0032]      FIG. 22  is a written listing of still further steps of the preferred program of the invention;  
         [0033]      FIG. 23  is a written listing of still further steps of the preferred program of the invention;  
         [0034]      FIG. 24  is a written listing of still further steps of the preferred program of the invention;  
         [0035]      FIG. 25  is a written listing of still further steps of the preferred program of the invention; and  
         [0036]      FIG. 26  is a written listing of still further steps of the preferred program of the invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0037]     Many of the fastening, connection, processes and other means and components utilized in this invention are widely known and used in the field of the invention described, and their exact nature or type is not necessary for an understanding and use of the invention by a person skilled in the art, and they will not therefore be discussed in significant detail. Also, any reference herein to the terms “left” or “right” are used as a matter of mere convenience, and are determined by standing at the rear of the machine facing in its normal direction of travel. Furthermore, the various components shown or described herein for any specific application of this invention can be varied or altered as anticipated by this invention and the practice of a specific application of any element may already by widely known or used in the art by persons skilled in the art and each will likewise not therefore be discussed in significant detail.  
         [0038]      FIG. 1  shows the present invention utilized in connection with a self-propelled windrower  10 ; however, it will be appreciated that the principles of the present invention are not limited to a self-propelled windrower, or to any specific type of harvesting machine.  
         [0039]     In the illustrated embodiment, the self-propelled windrower  10  comprises a tractor  12  and a header  14 , header  14  being attached to the front end of a frame  18  or chassis of the tractor  12 . The header may be of generally any suitable construction and design, and will include crop-harvesting mechanisms, such as a sickle cutter  20 . Windrower  10  includes a propulsion driveline  22  controllably operable by an operator riding in an operator cab for propelling the windrower in a desired speed and direction. Header  14  additionally includes a reel  24  rotatable at a fixed or variable speed, as denoted by arrow A, for directing crops toward header  14  for harvesting by sickle cutter  20 , as windrower  10  is moved over a field. A draper  26  comprising endless belts is disposed and operable for directing the harvested crop toward the center of header  14 .  
         [0040]     Reel  24  of header  14  is rotatably driven in direction A by a drive  34  which preferably includes a fluid motor  36 . Fluid motor  36  is connected in fluid communication with a reel driveline  38  of tractor  12 , by fluid lines  40  and  42 , for receiving pressurized fluid therefrom. Sickle cutter  20  and draper  26  are separately driven utilizing any desired drive such as a fluid PTO drive, or the like.  
         [0041]     Header  14  is removably mountable on a pair of lower arms  50  which extend forwardly from frame  18  of tractor  12 , and which are movable upwardly and downwardly for positioning the header at a desired cutting height, or at an elevated transport position, using one or more lift cylinders (not shown), also in the well known manner. The upper end of the header is connected to frame  18  by an upper or center link connected to a mechanism operable for tilting the header to a desired orientation, again, in the well known manner.  
         [0042]     Reel driveline  38  includes a fluid valve arrangement  52  controllably operable for directing pressurized fluid through fluid lines  40  and  42  as desired or required for powering reel  24 . The flow of pressurized fluid to valve arrangement  52  is generated by a fixed displacement pump  66  driven by an engine  68  of windrower  10 . Engine  68  also powers propulsion driveline  22  for propelling windrower  10 .  
         [0043]     Referring also to  FIG. 2 , the flow of pump  66  to motor  36  is controlled by a reel speed proportional solenoid  54 . Solenoid  54  is controlled by a control signal which is preferably an electrical signal, the electrical current value of which can be very precisely controllably varied through a range between zero and a greater amount. And, it is been found that reel driveline  38  can be configured such that the rotational speed of reel  24  will be linearly related to the electrical current value. Reel driveline  38  includes a programmable control module  60  connected to solenoid  54  by suitable conductive paths  62 , which can be, for instance, wires of a wiring harness. Control module  60  is preferably a conventionally constructed and operable microprocessor based tractor control module, or the like, suitably located on tractor  12 , such as in an operator cab  64 . A reel speed mode switch  70  and a reel speed switch  72 , are additionally connected to control module  60  by conductive paths  62 . Reel speed mode switch  70  is operable by an operator for inputting command signals to control module  60  for initiating and selecting an operating mode of reel  24 . Reel speed switch  72  is operable by an operator for increasing or decreasing and operating speed of reel  24 . Additionally, a display device  78  is operable for displaying information relating to the operation of reel  24 , as well as other systems of windrower  10 . Switches  70  and  72 , and display device  78 , are located within operator cab  64 .  
         [0044]     Reel  24  can be driven at any speed within a range of from zero to about 80 rpm, and will typically be driven a speed between about 20 and 78 rpm. In this regard, if reel  24  is driven at a rotational speed wherein a lower radial outer periphery of the rotating reel is moving at a speed relative to the ground and crops to be harvested which is slower than the travel speed of header  14 , the reel may have a tendency to engage and push the crops in the forward direction, away from sickle cutter  20 , which is typically not desired. Instead, it is desired to direct the crop toward sickle cutter  20 . As a result, in most instances, it will be desired to rotate reel  24  at a speed which propels the lower outer periphery of the reel at a speed in relation to the ground at least equal to the ground speed of header  14 , which will also be the ground speed of windrower  10 .  
         [0045]     Propulsion driveline  22  includes a pair of drive wheels, the rotational speed of which is monitored to generate information representative of a ground speed of windrower  10 . Therefore, the ground speed of windrower  10 , at any time, can be known. Reel speed switch  72  can be utilized for inputting speed commands to control module  60 , which, in turn, will output control signals to reel speed proportional solenoid  54  for delivering pressurized fluid to fluid motor  36  of drive  34 . Given a known diameter of reel  24 , the speed of the lower periphery of reel  24  can be determined from a rotational speed of the reel. If the speed of the lower periphery of the reel is determined, and the ground speed of the windrower is known, then the speed of the lower periphery relative to the ground can be determined. What is needed then, is a capability to determine a range of values for the control signal, that is, electrical current values, which will drive fluid motor  36  within a known range of speeds corresponding to a predicted range of ground speeds of windrower  10 . This capability is provided by the steps of program disclosed in  FIGS. 3 through 14 .  
         [0046]     Essentially, in a reel speed calibration mode the speed of engine  68  is automatically set and held. The engine speed is predetermined and will be sufficient for operating pump  66  at the system pressure for reel driveline  38 . An emergency stop for preventing operation of PTO for driving sickle cutter  20  will be engaged. Then, an electrical control signal having a known first current value, will automatically be applied to solenoid  54  by control module  60 . The first current value will preferably be sufficient for rotating reel  24  at a relatively slow speed. The number of rotations of reel  24  for a predetermined time interval, as driven by the first current value, will then be counted. This can be done by an operator observing and counting the rotations, or by a suitable speed sensor configured for determining the rotational speed of reel  24 , if present. The count will then be entered into a register of control module  60 . This can be done in a suitable manner, such as using a touchscreen feature of display device  78 , if present, or utilizing one of the other switches, such as by jogging speed switch  72  to select a value.  
         [0047]     When the count has been successfully entered, control module  60  will automatically apply a control signal to solenoid  54  having a predetermined second current value, which will preferably effect rotation of reel  24  at a faster speed than the first current value. The number of rotations of reel  24  for a predetermined time interval, as driven by the second current value, will then be counted. Again, this can be done by an operator observing and counting the rotations, or by a suitable speed sensor configured for determining the rotational speed of reel  24 , if present. The count will then be entered into a register of control module  60 .  
         [0048]     Next, current set points will be determined. This will comprise the speeds of rotation of reel  24  for each of the first and second current values. Because the relationship of reel speed to current value can be configured to be substantially linear, a linear function for relationship defining the rotational speed of reel  24  as a function of electrical current value, can be determined. As a result, a rotational speed of reel  24  for a current value between the set points can be determined, as can rotational speeds beyond those set points, within a reasonable range. Again, if the rotational speed for a given current value is known, then the resulting speed of the periphery of reel  24  will be known.  
         [0049]     With this information, that is, the ability to control the peripheral speed of reel  24 , reel speed can be coordinated or matched with ground speed, as desired. Steps of the method of the invention for accomplishing this are set forth in the code listings of  FIGS. 15 through 26 . Reel speed mode switch  70  is operable according to the invention for selecting either manual or automatic control of reel speed. In a manual mode, control module  60  is programmed to allow a rotational speed of reel  24  of between about 20 rpm and about 78 rpm to be selected using reel speed switch  72 , by jogging the switch to either increase or decrease the reel speed in one rpm increments. In the automatic mode, which can be initiated by placing reel speed mode switch  70  in an automatic mode, control module  60  is automatically operable for controlling the reel speed at a selected percentage of ground speed within a range of from about 100% to about 130% of ground speed. The percentage of ground speed is selectable by an operator using reel speed switch  72  when in the automatic mode. As result, as the ground speed is varied, either by the operator, or as a result of other conditions, control module  60  will automatically vary the reel speed to maintain the selected percentage of the ground speed.  
         [0050]     As an additional feature, control module  60  is programmed such that, in the automatic mode, the reel speed will not be allowed to fall below a certain stored value, which will be the greater of a predetermined set value, such as 50 rpm, or the lowest speed value set while previously in the manual mode. This is advantageous for instance, for performing a turning maneuver, because the reel speed will not be allowed to drop below the certain stored value, and when the header is brought in to contact with crop to be cut it will not be allowed to move so slow as to push the crop down.  
         [0051]     It will be understood that changes in the details, materials, steps and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the inventions. Accordingly, the following claims are intended to protect the invention broadly as well as in the specific form shown.