Abstract:
A feed system that is configured to more effectively grab and pull brush and tree materials into a chipper is provided. The system of the present disclosure is configured such that a large, heavy tree trunk can be continuously pulled into the chipper. The system includes two feed rollers one above the other in an offset arrangement.

Description:
This application is a National Stage Application of PCT/US2008/062207, filed May 1, 2008 in the name of Vermeer Manufacturing Company, a U.S. national corporation, applicant for the designation of all countries except the US, and Jeffrey D. Bradley, Edwin N. Galloway, James L. O&#39;Halloran and Justin J. Humpal, citizens of the U.S., applicants for the designation of the US only, and claims priority to U.S. Provisional Patent Application Ser. No. 60/928, 927, filed May 10, 2007, and which applications are incorporated herein by reference. To the extent appropriate, a claim of priority is made to each of the above disclosed applications. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to chipper devices and, more specifically, the feed system including feed rollers. 
     BACKGROUND OF THE INVENTION 
     Chippers are used to reduce branches, trees, brush, and other bulk wood products into small chips. Chippers typically include a feed chute, a feed system for controlling the feed rate of wood products into the chipper, a chipping mechanism, a drive system for powering the feed system and the chipping mechanism, and a discharge chute. The feed chute cooperates with the feed system to move the wood products towards the chipping mechanism. 
     Through the operation of the feed system, products to be chipped are brought into contact with the chipping mechanism, which grinds, flails, or cuts the wood products into small pieces. These chips are propelled into the discharge chute and expelled from the chipper. The overall performance of a chipper is dependent on the ability of the feed system to continually grab and pull wood from the feed chute into the chipper. An improved feed system is desirable. 
     SUMMARY OF THE INVENTION 
     The present disclosure relates to a feed system that is configured to more effectively grab and pull brush and tree materials into the chipper. The system of the present disclosure is configured such that a large, heavy tree trunk can be continuously pulled into the chipper. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a chipper according to the principles of the present invention with certain portions of the chipper shown in hidden lines; 
         FIG. 2  is a top view of the chipper according to  FIG. 1  with certain portions of the chipper shown in hidden lines; 
         FIG. 3  is a side cross-sectional view of the chipper along lines  3 - 3  in  FIG. 1 ; 
         FIG. 4  is a side cross-sectional view of the chipper along lines  3 - 3  in  FIG. 1  with a log on the feed chute; 
         FIG. 5  is a side cross-sectional view of the chipper along lines  3 - 3  in  FIG. 1  with a log engaged in the feed rollers; 
         FIG. 6   a  is a perspective view of a feed roller of  FIG. 1 ; 
         FIG. 6   b  is an end view of a tooth of  FIG. 6   a;    
         FIG. 7  is a perspective view of an alternative embodiment of a feed roller of  FIG. 6   a;    
         FIG. 8  is a perspective view of an alternative embodiment of a feed roller of  FIG. 6   a ; and 
         FIG. 9  is a perspective view of a feed roller of  FIG. 1  attached to a mounting arm. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1-5  a chipper is shown. In the depicted embodiment the chipper  10  is mounted to a frame  12  that rests on wheels  14 , which enable the chipper  10  to be conveniently moved. The depicted chipper  10  includes a feed chute  16 , which is also commonly referred to as a feed table. The feed chute  16  can be any structure located at the rear of the chipper  10  that facilitates the loading of materials to be chipped into the chipper  10 . (The material to be chipped can be any material that the user desires to reduce to chips. The material is most commonly brush and tree parts, therefore, for convenience the material to be chipped will be referred to herein interchangeably as wood, trees, or brush.) The chipper  10  in the depicted embodiment includes a feed system  18  that grabs and pulls brush from the feed chute  16  into a body portion  20  of the chipper  10  which houses cutters  80  (see  FIG. 3 ) that cut the brush into small chips. The cutters  80  are shown as blades mounted on a drum  81 . However, it should be appreciated that the cutter can be any structure that is capable of breaking the material to be chipped into chips. Once the material is broken into small chips, the chips are then projected out of the chipper  10  through a discharge chute  22 . 
     The feed chute  16  is provided at the rear of the chipper  10  to facilitate the loading of brush and trees into the chipper  10 . In the depicted embodiment the feed chute  16  includes a flat table portion  24  (loading surface) and two angled side walls  26 ,  28 . It should be appreciated that many other configurations of the feed chute  16  are possible. Feed chutes are described in greater detail in a related application filed on May 10, 2007 titled Wood Chipper Infeed Chute, which is incorporated herein by reference. Once the brush is grabbed by the feed system  18 , the brush is moved into contact with the cutter drum  30  that is housed within the body  20  of the chipper  10 . The cutter drum  30  spins cutting blades  80  at a high rate of speed which thereby reduces the brush and wood that contacts the drum  30  into small chips that are projected out the discharge chute  22 . Drum arrangements are described in greater detail in a related application filed on May 10, 2007 titled Chipper Drum with Integral Blower which is incorporated herein by reference (No. 60/928,928). 
     Still referring to  FIGS. 1-5 , the feed system  18  of the chipper is described in greater detail below. In the depicted embodiment the feed system  18  includes an upper feed roller  32  and a lower feed roller  34 . In the depicted embodiment, the upper feed roller  32  rotates counter clockwise and the lower feed roller  34  rotates clockwise to grab and pull material into the chipper  10 . In the depicted embodiment, the rotation is powered by a hydraulic drive motor (not shown). In the depicted embodiment the lower feed roller  34  is positioned closer to the chute  16  than the upper feed roller  32 . In the depicted embodiment the axis of the lower feed roller  34  is below the table portion  24  of the feed chute  16 . At least the teeth on the lower feed roller  34  are projecting above the surface of the table  24 . In the depicted embodiment, portions of the lower feed roller other than the teeth extend above the surface of the table  24 . Also, in the depicted embodiment the upper and lower feed roller overlap when viewed from above. In the particular embodiment, the overlapping portion of the upper and lower feed rollers measured horizontally in the front-to-back direction is less than the radius of the lower feed roller. In the depicted embodiment, the axis of the lower feed roller  34  does not overlap with the outer surface of the upper feed roller  32 . 
     Referring to  FIGS. 4 and 5 , a log  36  is shown being loaded into the chipper  10 . In  FIG. 4  the log  36  is shown on the table portion  24  of the chute  16  engaged with the lower feed roller  34 . The lower feed roller  34  engages the bottom surface of the log  36  and drags the log  36  up against the upper feed roller  32 . The upper feed roller  32  climbs the end of the log  36  and engages the top surface of the log  36 . Then the upper and lower rollers  32 ,  34  together pull the log  36  into the chipper body  20 . The relative position of the feed rollers enables the above sequence. It should be appreciated, that in alternative embodiments other relative positions are also possible. For example, in an alternative embodiment the axis of the lower feed roller  34  might overlap with the outer surface of the upper feed roller  32 . 
     Referring to  FIGS. 3-5  and  9 , the upper roller  32  is shown mounted to a bracket assembly  39  that allows the upper roller  32  to pivot up and down to adjust for the different thickness of logs and brush. The bracket assembly includes a pair of arms  38 ,  40  that rotatably connect to the first end  46  and the second end  48  of the upper feed roller  32 . The arms  38 ,  40  have a length L 1  that extend in a front-to-back direction relative to the chipper body. Ends  41  of the arms  38 ,  40  pivotably attach to the body of the chipper  10  about a horizontal axis that extends across the width of the chipper. In the depicted embodiment a cylinder  42  is attached to both arms  38 ,  40  to apply pressure and dampen the motion of the upper feed roller  32 . In the depicted embodiment the cylinders are active (powered), but it should be appreciated that in other embodiment they can be passive (not powered). Also, a guard  44  is mounted between the arms  38 ,  40  on top of the feed roller  32  to prevent brush from entering the chipper  10  above the upper feed roller  32 . The length L 1  of the arms in the depicted embodiment is greater than the diameter D 1  of the upper feed roller  32 . In the depicted embodiment the length L 1  is about 30 inches and D 1  is about 20 inches. The length of the arms  38 ,  40  can have an affect on the ability of the upper feed roller  32  to climb the end of log  36 . It should be appreciated that many other configurations of the bracket assembly  39  are possible. For example, in some embodiments springs are attached to the arms to bias the upper feed roller  32  downwardly to ensure that the upper feed roller  32  solidly engages the logs. Systems for applying down pressure are described in greater detail in a related application filed on May 10, 2007 titled System for Controlling the Position of a Feed Roller which is incorporated herein by reference (the serial number of the application has not been assigned). 
     Referring to  FIGS. 6   a ,  6   b ,  7 , and  8  the feed rollers  32 ,  34  are described in greater detail. The upper feed roller  32  is shown in  FIG. 6   a . Across the surface of the upper feed roller  32  are a plurality of claws  50  that are configured to dig into logs and brush to pull such material into the chipper  10 . In the depicted embodiment the upper feed roller  32  includes rows of claws  50  that define gripping paths. The claws  50  in adjacent rows are staggered such that the claws  50  in the same gripping path are spaced apart a distance D 2  which is twice the distance D 3 , which is the distance that each row is spaced apart. In the depicted embodiment, each row includes five claws  50  and there are a total of 10 rows equally spaced apart. Each of the claws  50  are spaced apart by a distance D 4  and each claw  50  has a length D 5 . In the depicted embodiment, D 4  is greater than D 5 ; therefore, there are gaps between the claw  50  columns. In one embodiment D 4  is about 4-5 inches and D 5  is about 3-4 inches. The gaps have a width equal to half of the difference between D 4  and D 5 . Each claw  50  has an asymmetric side profile that includes a sharp edge which enables it to dig into the surface of a log. The height H 1  of the claws  50  is related to the spacing D 2 . In the depicted embodiment the height H 1  and distance D 2  are configured such that one or more claws  50  are engaged in the surface of a log  36  at all times. In one embodiment the diameter of the upper feed roller is about 15-25 inches and the height of the teeth in each of the 10 rows is about ½ to 2 inches. In the same embodiment the diameter of the lower feed roller is about 9-12 inches and the height of each of the teeth in the 6 rows is about ¾ to 2 inches. In the depicted embodiment, the teeth have thickness T 1  between about ½ to 1½ inches and the top surface is angled θ at between about 45-65 degrees relative to the surface that extends generally perpendicularly away from the feed roller. In the depicted embodiment the teeth are asymmetrical in that they are configured to operate different depending on the direction of rotation. In the depicted embodiment the teeth are configured to engage the material to be chipped more aggressively when pulling the material into the chipper than when backing the material out of the chipper. In the depicted embodiment the claws are sized and spaced apart such that at least one claw of the upper feed roller and at least one claw of the lower feed roller engage the surface of a log held between the upper and lower feed rollers. To accomplish this end, in the depicted embodiment a line connecting the tip of the claws in adjacent rows does not cross into the outer surface of the feed rollers. It should be appreciated that the inclusion of actual and relative sizes herein is not meant to be limiting. Many other different configurations are possible. 
     Referring to  FIG. 7 , an alternative embodiment of the feed roller  32  is shown. The feed roller  61  is generally cylindrical in shape. In the depicted embodiment the bars  63  run along the length of the feed roller  61  and connect to the claws  51  to provide auxiliary support to the claws  51 . In certain conditions, the bars  63  are also advantageous in that they aid in the feeding. For example, the bars  63  can be equally or even more effective that the claws  51  in feeding brush. 
     Referring to  FIG. 8 , another alternative embodiment of the feed roller  32  is shown. The feed roller  60  is generally cylindrical in shape. Instead of rows of claws  50 , the roller  60  includes a number of a ribbed plates  62  fixed to the outer surface of the feed roller  60 . In the depicted embodiment the ribbed plates  62  are spaced apart by a distance D 6 . Each ribbed plate  62  includes a plurality of peaks  64  and valleys  66  thereon that are spaced apart by a distance D 7 . In the depicted embodiment the ribbed plates  62  are welded onto the outer surface of the feed roller  60 . The ribbed plates  62  are configured to grab and pull material into the chipper  10  when rotated. It should be appreciated that many other variations of this embodiment are possible. 
     Referring back to  FIG. 1 , a fourth embodiment of a feed roller configuration is shown. The lower feed roller  34  is shown to include a number of claws  70  that are connected to each other and welded to the outer surface of the feed roller  34 . The claws  70  are similar in configuration to those claws  50  illustrated in  FIG. 6   a  and described in detail above. The claws  70  in  FIG. 1  are connected together like the peaks  64  in the embodiment shown in  FIG. 8 . The claws  70  are shorter than the claws  50 . The claws  70  in each row are offset from each other like the claws  50  in the embodiment shown in  FIG. 6   a . The claws  70  and  50  are orientated such that when the upper feed roller  32  rotates counterclockwise and the lower feed roller  34  rotates clockwise, together they grab and pull materials to be chipped into the chipper  10 . It should be appreciated that many other embodiments of the feed rollers are possible. 
     The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.