Patent Publication Number: US-2011047949-A1

Title: Double tapered knife rolls

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is directed to improved stalk rolls as may be used with corn harvesters and in particular to a stalk roll with multiple tapered sections to improve feeding of corn stalks. 
     2. Prior Art 
     Prior art corn harvesters include headers with multiple row crop dividing assemblies for directing corn stalks into harvesting gaps defined between the dividing assemblies. Gathering chains or other devices in the gaps draw the stalk toward the header. Stalk rolls, also known as knife rolls, pull the stalks rapidly downward between the stalk and the field. Typically, plates are located above and adjacent the stalk rolls to separate the ears from the stalk and to prevent the ears of corn from passing between the plates. The ears of corn are snapped from the stalk and directed to the combine. It is generally desirable to maintain at least some of the stalks in the field for erosion control and to recycle the plant materials. It is an advantage to chop up the stalk rows to aid in decomposition. Smaller pieces of chopped stalk also tend to eliminate or minimize plugging of tilling tools on the machinery used in the field. 
     A problem with harvesters is trash on the head and throughout the combine. This can be reduced by improving the feed and handling of stalks. Moreover, improved feeding along the stalk roll improves crushing and crimping of the stalks and conditions residue to reduce wind and water erosion. The improved conditioning also leads to less plugging for fall tillage and provides stalks that are better for bedding and baling. Crushing and crimping treatment of stalks by the harvester also improves field planting conditions. The stalk rolls should also work under a wide variety of stalk and harvesting conditions. 
     Typical stalk rolls include a core portion with flutes or ridges mounted around the body of the roll, and a nose portion with a helical vane. Such a configuration may include a tapered portion at the leading edge of the stalk roll near the nose portion. Such a configuration has generally been effective at providing feed through the head and combine. However, under certain conditions, the corn stalks do not enter into the pair of knives sufficiently. This may cause plugging and ineffective crimping or crushing that may lead to problems with the harvester and in the field when the stalks are later engaged by other machinery. In addition, it has been found that the stalk rolls may wear better with a tapered design. Although a taper may improve wear, there still may be uneven wear and that such uneven wear may reduce the useful life of a stalk roll. 
     It can be seen that a new and improved harvester, corn head, and stalk rolls are needed. Such a stalk roll should aid in providing feed of the stalks through the corn head and improving the condition of the stalks remaining in the field. Moreover, such stalk rolls should allow the stalks to enter a sufficient distance between the knife rolls to aid in reducing plugging throughout the harvester head and further in the combine. Such stalk rolls should also reduce uneven wear to increase the life of the stalk rolls. The present invention addresses these as well as other problems associated with combines, corn harvester heads, and stalk rolls. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to stalk rolls for a corn harvester. The harvester includes a head having row dividers that direct corn stalks to ear removal assemblies. An auger at the rear of the head directs ears to the combine portion of the harvester for further processing and separation. 
     The ear removal assembly includes a gathering assembly having belts with paddles that engage the corn stalks and pull them backward to stalk rolls. The stalk rolls pull the corn stalks downward so that the ears and corn are separated from the corn stalks as they pass between plates above the gathering assembly. Separated ears of corn pass to the auger for further processing. The corn stalks are pulled downward where they are crimped and cut by the stalk rolls and remain in the fields for decomposition to improve treatment of the fields and soil. 
     Each stalk roll includes an impeller at the leading end of the stalk roll. The stalk rolls are arranged in pairs and rotate in opposite directions to engage the corn stalks and fold them downward between the stalk rolls. The stalk rolls include a substantially cylindrical body and flutes extending outward from a periphery of the cylindrical body at an oblique angle. The edges of the flutes form knifes that cut the corn stalks. The stalk roll is configured with two tapering sections tapering downward from a rear cylindrical portion to the impeller. In one embodiment, the tapering sections are of approximately equal length and the two tapering sections together substantially equal the length of the cylindrical section. The double taper provides for improved feeding and direction of the corn stalks to the rear of the ear removal assembly and to the cylindrical sections of the stalk rolls. Problems related to plugging are reduced with such a configuration while the processing of the corn stalks is maintained and other problems associated with the stalk rolls are reduced. 
     These features of novelty and various other advantages that characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings that form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Referring now to the drawings, wherein like reference numerals and letters indicate corresponding structure throughout the views: 
         FIG. 1  is a top plan view of a harvester according to the principles of the present invention; 
         FIG. 2  is a perspective view of a corn head for the harvester shown in  FIG. 1 ; 
         FIG. 3  is a side elevational view of the corn head shown in  FIG. 2 ; 
         FIG. 4  is a top plan view of a stalk feeder assembly for the corn head shown in  FIG. 2 ; 
         FIG. 5  is a perspective view of the stalk feeder assembly shown in  FIG. 4 ; 
         FIG. 6  is a front perspective view of the stalk feeder assembly shown in  FIG. 4 ; 
         FIG. 7  is a side elevational view of a stalk roll for the stalk feeder assembly shown in  FIG. 4 ; 
         FIG. 8  is a front elevational view of a pair of the stalk rolls shown in  FIG. 7 ; 
         FIG. 9  is a rear elevational view of the pair of stalk rolls shown in  FIG. 8 ; 
         FIG. 10  is a perspective view of the pair of stalk rolls shown in  FIG. 8 ; and 
         FIG. 11  is a top plan view of the pair of stalk rolls shown in  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings and in particular to  FIG. 1 , there is shown a harvester, generally designated  20 . Head  22  and threshing components are generally designated  24 . Harvesters  20  typically include a cab  26  where the operator sits and drives the harvester  20  and operates the various controls. Wheels  28  are typically mounted on the harvester  20  behind the head  22 . The head  22  may be interchangeable with other heads for performing other tasks or for use with other crops. 
     As shown in  FIGS. 1-3 , the head  22  includes a frame  40 . The head  22  is supported on the front of the harvester  20  and also may have skids  46  to maintain the front of the head  20  raised up from the ground. The head  22  includes row dividers  32 , which include a cone shaped front portion and provide for directing the corn stalks into ear removal assemblies  30 . An auger  34  includes a drive  44  to feed the ears of corn removed from the stalks to an opening  42  from the rear of the head  22 . The auger  34  includes a left helical vane  36  and a right helical vane  38  that direct the ears of corn to the center opening  42  for further storage and processing by the harvester  20 . 
     Referring to  FIGS. 4-6 , the ear removal assembly  30  includes a stalk row gathering assembly  50 . The gathering assembly  50  engages corn stalks directed to the ear removal assembly  30  by the row dividers  32 . The corn stalks are engaged by paddles  54  on rotating belts  52 . The belts  52  include lugs  56  that are driven by drive sprockets  60  and also extend around idler sprockets  58 . A motor  62  drives the sprockets  60  and tensioners  64  to maintain proper spacing for tensioning the belt  52 . The gathering assembly  50  includes pairs of belts  52  so that the paddles  54  extend toward one another and engage the corn stalks. Although belts  52  are shown, it is also known in the art to use gathering chains with paddles mounted on the chains for engaging the corn stalks. The corn stalks are pulled rearward and the ears of corn engage opposing plates  66  above the gathering assembly  50  and are removed as the stalks are pulled down by the stalk rolls  70 , as explained hereinafter. It can be appreciated that the gathering assembly paddles  54  will then push the ears rearward to the auger  34 . 
     In addition to being directed rearward by the gathering assembly  50 , the stalks are pulled downward by an opposed pair of stalk rolls  70 . The stalk rolls  70  are positioned below the belts  52  of the gathering assemblies  50 . The stalk rolls  70  are mounted to rotate about a substantially horizontal axis extending generally along the direction of travel. Each stalk roll  70  includes a center tube  78 . Around a periphery of the tube  78  are mounted flutes  76 . Each of the flutes  76  has a knife edge  80  that provides for crimping and chopping the stalk rolls for improved treatment prior to the stalk roll  70  being returned to the field. At the front of each stalk roll  70  is an impeller  72  having a helical vane  74 . The impeller  72  forms a nose that engages the corn stalks by the vane and directs the stalks rearward. In conjunction with the paddles  54  and the gathering assemblies  50 , the stalk rolls  70  are generally pulled rearward to be engaged by the flutes  76  of the stalk roll  70 . 
     As shown most clearly in  FIG. 9 , the tube  78  has a keyed inner surface that allows for mounting the stalk roll  70  to a drive  60  and to impart rotation to each stalk roll  70 . 
     Referring now to  FIGS. 10 and 11 , each stalk roll  70  behind the impeller  72  includes three sections. A first section  82  is substantially cylindrical. A second section  84  is tapered at a first angle and a third section  86  is tapered at a second angle greater than the first angle. In one embodiment, the first section  82  is approximately 12 inches long; the second section  84  is approximately 6 inches long and the third section  86  is also approximately 6 inches long. A typical diameter to the outer edge of the knife edges  80  is approximately 3.5 inches in one embodiment. The taper from the first section  82  would be from approximately 3.5 inches to approximately 3.25 inches. The taper in the third section  86  would be from approximately 3.25 inches to approximately 2.5 inches. In addition, it can be appreciated that in one embodiment, the stalk roll  70  includes six flutes  76  and that the flutes  76  have a substantially constant width but taper along the body of the stalk roll  70 . Moreover, as shown in  FIGS. 8 and 9 , the flutes  76  extend at an oblique angle relative to a radius of the stalk roll  70 . Therefore with six flutes  76 , the angle between adjacent flutes is approximately 60°. 
     In operation, the harvester  20  is generally advanced along a direction of travel following the rows of the corn field. The row dividers  32  are positioned to extend between the rows so that the corn stalks are directed to the ear removal assemblies  30 . As the corn stalk is at the front of the gathering assembly  50 , the paddles  54  on the belt  52  engage the stalk and pull it rearward. In addition, below the gathering assembly  50 , the impeller  72  of the stalk roll  70  engages the corn stalks and pulls them rearward. As the paddles  54  continue to push the corn stalk rearward, the stalks are engaged by the stalk roll  70 . The pairs of stalk rolls  70  are rotated in opposite directions so that the stalk rolls  70  pull downward when positioned between each pair of stalk rolls  70 . 
     When the corn stalks are engaged by the stalk rolls  70 , the flutes  76  pull the stalk rolls  70  downward. This engagement and motion accomplishes several things. As the stalks are pulled downward, the ears engage the plates  66 . The distance between the plates  66  is smaller than the width of the ears of corn. Therefore, ears of corn are separated from the stalk. The separated ear is pushed backward by the continued rearward to be engaged by the auger  34  and is fed to the other components of the harvester combine  20 . In addition, the stalks themselves are treated by the stalk rolls  70  and the flutes  76  and the knife edges  78 . The knife edges  78  chop the stalk rolls  70  for the flutes  76  crimp the corn stalks as they are pulled downward between the bodies of the stalk rolls  70 . After the stalk rolls  70  are pulled downward, they are left in the field to decompose. The crimping aids in the decomposition to provide for better treatment of the treatment for future planting. The cutting leaves smaller pieces in the field, which also aids in decomposition and provides for better treatment of the soil and decomposing corn stalks that are left in the field. 
     It has been found that the double taper also provides for smoother transitions as the corn stalk is pulled further along the body of the stalk roll  70  than conventional knife rolls. Therefore first and second tapered sections  84  and  86  provide for smoother movement of the corn stalks rearward and decrease the plugging problems associated with the prior art. It has also been found that the double taper leads to improved wear from better feeding of the corn stalks rearward. 
     It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.