Abstract:
A pair of rake wheels in an assembly is referred to as a center splitter assembly. Each rake wheel is configured for free-rotation, meaning it is powered by contacting the ground. The center splitter is used to separate material, each wheel moving material in a different direction. The rake wheel on the left side of the center splitter assembly will rotate in a clockwise direction, as viewed from behind the wheel, which will cause the material to move from the right to the left. The opposite applies to the rake wheel on the right side of the center splitter assembly, where it will rotate counter-clockwise, moving material from the left to the right. Since these rake wheels are attempting to move material in opposite directions, the spacing between the wheels has been found to be critical.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 61/373,579 filed Aug. 13, 2010 entitled “Center Splitter for Rake” which is incorporated by reference herein in its entirety. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       REFERENCE TO MICROFICHE APPENDIX 
       [0003]    Not applicable. 
       BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0004]    Various types of rakes are known to include a left side raking device, that moves material from the left to the middle, and a right side raking device, that moves material from the right to the middle, to form a windrow in the middle of the machine. These rakes are often referred to as V-Rakes, due to the configuration that has the shape of the letter “V”, when in the operating position. The windrows typically range from 2½ feet wide to 5 feet wide, typically being formed under the main frame of the raking device. The material lying on the ground in the location of the forming windrow is not turned or moved by either the left or right raking devices. It is advantageous to move that material, thus there is a need for a device to operate in the vicinity, typically under, the main frame of the rake, to move material off the ground in the location where the final windrow will be formed. 
         [0005]    Examples of such devices in a variety of configuration can be found. However, there is a need for an improved device that provides more reliable operation, and that is cost effective to manufacture, and that fits conveniently onto the typical structure of the rake. 
         [0006]    One type of rake, known as a wheel rake, commonly includes a set of generally planar rake wheels, each including a set of tines. Each rake wheel is oriented generally perpendicular to the ground. Some of the tines of each wheel contact the ground such that movement of the rake subsequently causes the wheel, along with all its tines, to rotate. The tines that are in contact with the crop material will subsequently lift and move the crop material along the ground. 
         [0007]    Wheel rakes configured as V-rakes have a set of left rake wheels and a set of right rake wheels. Forward movement of the rake will cause the wheels to rotate. When viewed from behind each wheel, the wheels on the left side will rotate counter-clockwise, which will cause the material, typically hay or straw, to be moved from left to right. The wheels on the right will rotate clockwise, and the material, typically hay or straw, will be moved from right to left. 
         [0008]    Ground driven rake wheels are known to be configured in non-planar configurations, one example being described in U.S. Pat. No. 2,588,599 wherein a single wheel is used to move material. This general configuration has also been described for other applications as described in U.S. Pat. No. 4,583,307 wherein a set of wheels is configured to move material in one direction. 
       BRIEF SUMMARY OF THE INVENTION 
       [0009]    The current invention utilizes a pair of rake wheels in an assembly that will be referred to as a center splitter assembly. Each rake wheel is configured for free-rotation, i.e., to be powered by contacting the ground as described above, but with a modified tine profile, and modified orientation. The center splitter is used to separate material, each wheel moving material in a different direction. The rake wheel on the left side of the center splitter assembly will rotate in a clockwise direction, as viewed from behind the wheel, which will cause the material to move from the right to the left. The opposite applies to the rake wheel on the right side of the center splitter assembly, where it will rotate counter-clockwise, moving material from the left to the right. Since these rake wheels are attempting to move material in opposite directions, the spacing between the wheels has been found to be critical. 
         [0010]    The center splitter assembly is located in a position on the machine where space is limited. The present invention provides a solution that fits in the available space, allows the rake to fold to a transport orientation, while providing adequate performance by positioning each rake wheel with an effective raking distance that extends from the approximate center of the mount frame, to a distance away from the center. 
         [0011]    In addition to drying material, lifting and turning the crop at that location can increase the efficiency of the baler/harvester to pick up the crop from the stubble. The splitter lifts the hay off the ground allowing the pickup on the baler to clean the ground better. This allows the baler operator to increase efficiency (drive faster, less crop loss). For the same reason, the splitter is also beneficial for crops that have been rained on causing them to lay closer/flatter to the ground. 
         [0012]    Spacing the wheels apart by a minimum distance as specified in the attached claims allows the splitter to part longer crops which is typical of most hay conditions. The first prototypes tested in the field by the inventor had the rake wheels too close together. This caused the same pieces of crop to engage both wheels. This, in turn, caused the wheels to fight each other and eventually stop rotating because the wheels pull in opposite directions. 
         [0013]    The mounting arrangement of the rake wheels in the center splitter assembly has also been found to be critical to proper function. Each rake wheel is independently mounted on a trailing arm support, with a common lift device. The preferred embodiment of the lift device is a hydraulic cylinder that will lift and lower both rake wheels simultaneously. Once lowered, each rake wheel can rise independently to follow the contour of the ground, or to raise to travel over top of other obstructions. 
         [0014]    The mounting of the rake wheel is important to good rake wheel life. The rake wheel “trails” behind the pivot point and slots on the mount allow the rake wheel to follow the ground and rise over bumps. This configuration also removes the need for suspension that is typical of wheel rakes. This mounting reduces ground pressure as the rake passes over the field. The latest test stand results show the splitter tines of the instant invention out live standard tines by over three times. 
         [0015]    A major advantage of the mounting arrangement of the rake wheels on the center splitter of the present invention is that there is no need for suspension to obtain increased rake tine life. The center splitter rake wheels assembly of the present invention follows contour of ground, and when plugging starts to occur the wheels tend to lift, which prevents damage to the components. 
         [0016]    The preferred embodiment has the center splitter lift cylinder connected in series with the lift system for the main rake arms, so that lifting and lowering can be accomplished with a single hydraulic circuit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  is a top view of a prior art rake wheel moving to the left and showing the forces imposed on the rake wheel; 
           [0018]      FIG. 2  is a side view looking in a direction perpendicular to the direction of movement of the rake wheel, with emphasis on one of the tines shown at the bottom of  FIG. 2 ; 
           [0019]      FIG. 3  shows a number of tines that attach at a first end to a center hub, pass through a rim and terminate at the second end at a straight section that functions to contact and move crop material; 
           [0020]      FIG. 4  also shows a number of tines that attach at a first end to a center hub, pass through a rim and terminate at the second end at a straight section that functions to contact and move crop material; 
           [0021]      FIG. 5  is a top view of only three of the many tines in the wheel rake of the present invention; 
           [0022]      FIG. 6  is a side view that shows the configuration of only three of the many tines in the wheel rake of the present invention: 
           [0023]      FIG. 7  is a top view showing two rake wheels of the current invention are placed in the center, in a center splitter assembly, each working to move material in an opposite direction, to spread the material that would otherwise have not been moved; 
           [0024]      FIG. 8  is a side view illustrating the positioning of the new rake wheels in relation to prior art rake wheels; 
           [0025]      FIG. 9  is an isometric view illustrating the positioning of the new rake wheels in relation to prior art rake wheels; 
           [0026]      FIG. 10  is a front view that illustrates an advantage of the new rake wheels; 
           [0027]      FIG. 11  shows a rake of a configuration where the crop material centered on the location of the windrow being formed is left on the ground, undisturbed; 
           [0028]      FIG. 12  illustrates a lifting mechanism for the center splitter including a cylinder that moves a lifting pin as it extends and retracts; 
           [0029]      FIG. 13  shows the orientation of the lift arms, which are substantially horizontal, angled slightly up so that the lift arms pull the rake wheels; and 
           [0030]      FIG. 14  is a top view of the center splitter assembly. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0031]    By changing the tine profile of a full sized rake wheel, and repositioning its orientation, this known configuration of a raking device can function in a constricted area, such as under the frame or under the tongue of the machine. The advantage of using a full sized wheel (for example, about 56 inch diameter) is to reduce crop wrapping under certain conditions when compared to a smaller diameter rake wheel. 
         [0032]    The rake wheel is positioned at a compound angle which allows the tines to reach previously inaccessible areas, such as under tongues or frames. The tines of the rake wheel are bent to form an angle approximately perpendicular to the ground. This creates a dish shaped rake wheel. The result of tine profile allows the tines to drive the wheel and facilitate hay movement in constricted areas. A standard rake wheel in this position would cause the tines to passes over the crop without lifting and moving the crop. This present design is useful, when used as a pair, as a center windrow splitter for rakes where there is a necessity to reach under the frame to move crop. 
         [0033]      FIGS. 1 and 2  illustrate prior art rake wheels  10  that comprise a number of tines  100  that attach at a first end to a center hub  20 , pass through a rim  30  and terminate at the second end at a straight section that functions to contact and move crop material. The tines are generally located within a plane a-a, and include a center section  102 , a bent second section  104 , a straight lever-arm third section  106 , a bent forth section  108  and a straight raking section  110 . Each tine contacts the ground and or crop material as it rotates about the axis of rotation  40  of the wheel.  FIG. 2  shows a single tine at a lower position where the second end of that tine end is at the lowest position, where it will be in contact with the ground. The wheels are mounted on a frame that moves the rake wheel in a direction of travel to the left as illustrated in  FIG. 1 , such that the axis of rotation of the wheel is rotated from the direction of travel an angle  112 , more than 30 degrees. The movement of the wheel combined with the tine contact with the ground results in the generation of a tine force F T . The angled relationship of the wheel assembly to the direction of travel results in the force F T  having two components, a rotation force F R  and a crop force F C  as illustrated in  FIG. 1 . The rotation force F R  tends to cause the wheel to rotate about its axis of rotation  40 , while the crop force acts on and moves the crop material. It has been found that the angle  112  needs to be more than 30 degrees. If an angle of less than 30 degrees is utilized the wheel does not rotate adequately because the rotation force F R  will be proportionally lower. 
         [0034]    Still referring to  FIGS. 1 and 2 , this assembly works well for raking hay, and provides a reliable and cost effective construction. The effectiveness of the tine is a result of the load bearing characteristics of the tine. As noted above the end  110  will contact the ground and or the crop. The resultant force is transferred through the bent section  108  to the straight section  106  that acts like a lever arm, transferring the loading to the bent section  104  which is in contact with the rim. The resulting load conditions include bending load of the tine at the rim, but also a significant amount of torsional loading of the straight section  102 , that functions as a spring, to absorb much of the force. 
         [0035]    The current invention builds on the success of the prior art wheel, while also providing unique features. There is a need for a device to move crop material from the center location of a towed rake, as illustrated in  FIG. 11 . In a rake of this configuration the crop material centered on the location of the windrow being formed, illustrated as area  2 , is left on the ground, undisturbed. This is undesirable since that material will not dry as well as the material that has been raked, due to the fact that it is left on the ground and in closer contact with the ground than the raked material, and the fact that the raked material is placed on top. In addition, the material that is left on the ground is more difficult for a machine to pick-up during the harvest process. The rake wheels and rake of the current invention solve this problem. As illustrated in  FIG. 7 , two rake wheels  12  of the current invention are placed in the center, in a center splitter assembly, each working to move material in an opposite direction, to spread the material that would otherwise have not been moved. The resulting windrows, wherein all the material has been lifted off the ground and fluffed-up, will dry quicker and optimize the performance of the subsequent harvest operation, typically either a baler or a forage chopper. 
         [0036]    The new rake wheel  12  illustrated in  FIGS. 3 and 4 , comprises a number of tines  200  that attach at a first end to a center hub  20 , pass through a rim  30  and terminate at the second end at a straight section  210  that functions to contact and move crop material. The tines are similar to the tines of the prior art in that there is a center section  202  that acts like a torsional spring, a first bent section  204  located on adjacent the rim, a straight section  206  that acts like a lever arm. The rake tine of the present invention deviates from the prior art in the orientation of bend  208 , which includes a portion of the bend within the same plane as the first bent section, but also a portion of the bend in a different plane. This is illustrated in  FIGS. 5 and 6  which illustrates three tines  200  in a wheel.  FIG. 5  is a side view showing the bend  208  that results in the tine section  210  being located at an angle  216 , in a preferred embodiment  61  degree, deviation from the plane that contains the rest of the tine. This angle  216 , from the vertical plane in this figure, can be within a range from 30 to 70 degrees. The bend  208  is a compound bend, in that it also reorients the tine section  210  an angle  218  of approximately 90 degrees as shown in  FIG. 6 . 
         [0037]    With the tines formed as described above, the rake wheel  12  is oriented with its axis of rotation as shown in  FIGS. 3 and 4 , at a compound angle. As viewed from above in  FIG. 3  the axis of rotation is positioned an angle  212  from the direction of travel. This angle is similar to that used for the prior art wheels. The angle will be dependent on the tine profile, the preferred embodiment in this figure illustrates a configuration of approximately 30 degrees, where this angle can be varied between 20-40 degrees. 
         [0038]    As viewed from the side in  FIG. 4  the axis of rotation is positioned an angle  214  from the direction of travel, or relative to the ground. This is preferably set to orient the tine section  210  approximately perpendicular to the ground. Thus, there is a correlation between the angle  216  and the preferred angle  214 . If angles  214  and  216  are approximately equal, the tine section  210  will be approximately perpendicular to the ground. 
         [0039]      FIG. 7  is a view of a complete rake with the center splitter including two rake wheels  12  positioned ahead of the prior art wheels on a frame where the rake wheels  12  will move the material away from the center. The rake wheels  12  of the center splitter are between 50 inches and 60 inches in diameter and are spaced apart so that they are at least 6 inches apart at the closest point, labeled as dimension M. The material moved by the center splitter is subsequently moved, by the prior art rake wheels  12 , back towards the center to form a windrow, where all the material in the windrow has been lifted off of the ground for improved drying. 
         [0040]      FIG. 8  is a side view illustrating the positioning of the new rake wheels  12  in relation to prior art rake wheels  10 .  FIG. 9  is an isometric view illustrating the positioning of the new rake wheels  12  in relation to prior art rake wheels  10 .  FIG. 10  is a front view that illustrates an advantage of the new rake wheels  12 . Due to the fact that these wheels  12  are rotated as previously described they are capable of effectively reaching under the frame of the rake to move the material in the center off of the ground. This configuration also allows the rake wheels to be lifted out of the way in a transport position. 
         [0041]      FIG. 12  illustrates the lifting mechanism  300  for the center splitter including a cylinder  302  that moves a lifting pin  304  as it extends and retracts. Lifting pin  304  is attached to the main frame by plates  306  and  308  that are free to rotate about an axis of rotation  310  as the cylinder  302  moves the linkage of  FIG. 12 . The left side support  312  for the left rake wheel of the center splitter is pivotally mounted to freely rotate about axis  310 . The left side support  312  includes a torque arm  314  with a slot  316  aligned with lift pin  304 . The slot is configured to allow the left rake wheel to lift freely from a lowered position. 
         [0042]    Lift bar  318  is connected on one end to lift pin  304 , and on the opposite end to torque arm  320 . The torque arm  320  is part of the right side support  322  for the right rake wheel of the center splitter. Torque arm  320  includes a slot  324  that allows the right rake wheel to lift freely from a lowered position shown in  FIG. 12 . 
         [0043]      FIG. 13  illustrates the orientation of the lift arms  312  and  322 , which are substantially horizontal, angled slightly up so that the lift arms pull the rake wheels. 
         [0044]      FIG. 14  is a top view of the center splitter assembly  300  with wheels that are between 50 inches and 60 inches in diameter, and spaced apart so that they are at least 6 inches apart at the closest point, labeled as dimension M, wherein the tip diameter D of the rake wheels is at least six (6) times the minimum distance M between the outer tip diameter of the rake wheels. 
         [0045]    Increased tine life is an additional benefit to the orientation and profile of the rake tine on the center splitter wheel. The design and orientation of the tine greatly increases tine life. Standard rake wheel tines are seen to fail at a predictable number of hours whereas testing for over two weeks did not result in even one failed tine from the splitter rake wheel of the present invention. This is believed to be due to the fact that on a standard rake wheel the flexing of the tines occur at specific places on the tine, whereas the bending forces for the splitter rake wheel  12  are distributed more evenly throughout the length of each tine, resulting in longer life of the tines compared to standard tines. 
         [0046]    Accordingly, it will be appreciated that the preferred embodiments herein do indeed accomplish the aforementioned objects. Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.