Patent Publication Number: US-2021164129-A1

Title: Hemp stripping machine

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 62/942,794 filed Dec. 3, 2019 and U.S. Provisional Application No. 62/976,598 filed Feb. 14, 2020, which is hereby incorporated by reference. 
    
    
     FIELD OF DISCLOSURE 
     The present disclosure relates in general to harvesting equipment, and specifically deals with a machine and process for stripping leaves from the stalks of a hemp plant. 
     BACKGROUND 
     Humans have been using the hemp plant for thousands of years. Hemp is a fast growing plant and was one of the first plants to be spun into usable fiber 10,000 years ago. It can be refined into a variety of commercial items, including paper, textiles, clothing, biodegradable plastics, paint, insulation, biofuel, food, and animal feed. Oil can be obtained from the seeds, which can serve as a basis for a multitude of products. Using the hemp plant and its cultivation was commonplace until it was associated with its drug-type genetic sibling. Recently, there has been a reemergence of the hemp plant around the world. Cannabidiol (CBD) products are currently the center of an exploding market. CBD is obtained from the leafy biomass of the plant. As used herein, leafy biomass includes all the parts of the hemp plant excluding the stalk/stem, for example the leaves and flowers containing the plant&#39;s seeds. 
     Various methods and devices for separating the leafy biomass from the hemp stem are known. However, it is difficult to quickly and completely strip a hemp stem of its leafy biomass while maintaining a high yield rate. Therefore, it is desirable to have a simple, quick and efficient method and device to strip the leafy biomass from the hemp stems. 
     Thus, there is a need for improvement in this field. 
     SUMMARY 
     The present disclosure involves a plant stripping machine and process allowing a user to place a hemp plant into the machine wherein the leafy biomass is removed from the stalks. The user then pulls the stalks from the machine while the stripped material drops onto a conveyor belt which transports it for further processing. 
     The present machine includes an elongate casing having two ends and a pair of central ramp portions leading to a longitudinal entry slot. Arranged longitudinally below the respective ramp portions are a pair of rotating shafts. A plurality of stripping members extend radially and are spaced along the length of the shafts. Each shaft is rotationally driven. 
     The shafts are spaced so that the gap between them is below the entry slot and the stripping members radially overlap yet are longitudinally offset to alternate with each other. During operation, the shafts counter rotate so that the stripping members pull material downward between the two shafts and rotate upward on the outward sides. The stripping members are preferably made of slightly flexible materials, such as nylon forming a nylon cord. During operation, when a hemp plant is introduced through the entry slot, the stalks and leafy biomass pass between the shafts. While passing between the shafts, the stripping members function as flails to strip the leafy biomass from the stalks. The stripping members pull the leafy biomass downward while leaving the stalks intact. The stalks can then be withdrawn against the flailing of the stripping members, further ensuring that the stalks are completely stripped. 
     The floor of the machine is either open or forms a ramp leading to an exit opening optionally yet preferably arranged over a conveyor belt. The conveyor belt receives the leafy biomass that&#39;s been stripped from the stalks and transfers it away for further processing. 
     Further forms, objects, features, aspects, benefits, advantages, and embodiments of the present disclosure will become apparent from a detailed description and drawings provided herewith. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an example of a hemp stripping assembly including a hemp stripping machine and a conveyor assembly. 
         FIG. 2  is a perspective view of the hemp stripping machine of  FIG. 1  in a tilted position. 
         FIG. 3  is a perspective view of the hemp stripping machine of  FIG. 1  without the conveyor assembly. 
         FIG. 4  is a top view of the hemp stripping machine of  FIG. 3 . 
         FIG. 5  is a side view of the hemp stripping machine of  FIG. 3 . 
         FIG. 6  is a bottom view of the hemp stripping machine of  FIG. 3 . 
         FIG. 7  is a perspective bottom view of the hemp stripping machine of  FIG. 3 . 
         FIG. 8  is a perspective view of the hemp stripping machine of  FIG. 3  with the covers removed. 
         FIG. 9  is a perspective view of a stripping assembly from the hemp stripping machine of  FIG. 3 . 
         FIG. 10  is an enlarged perspective view of a shaft of the stripping assembly of  FIG. 9 . 
         FIG. 11A  is a cross-sectional view of the shaft of  FIG. 9 . 
         FIG. 11B  is a cross-sectional view of another embodiment of the shaft of  FIG. 9 . 
         FIG. 12  is a perspective view of another embodiment of a shaft of the stripping assembly of  FIG. 9 . 
         FIG. 13  is an exploded view of the shaft of  FIG. 12 . 
     
    
    
     DESCRIPTION OF THE SELECTED EMBODIMENTS 
     For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the disclosure as described herein are contemplated as would normally occur to one skilled in the art to which the disclosure relates. One embodiment of the disclosure is shown in great detail, although it will be apparent to those skilled in the relevant art that some features that are not relevant to the present disclosure may not be shown for the sake of clarity. 
     The present disclosure involves a plant stripping assembly which is used to strip the leafy biomass from the stalk of a hemp plant. As used herein, leafy biomass includes all the parts of the hemp plant excluding the stalk/stem portion, for example the leaves and flowers containing the plant&#39;s seeds. The plant stripping assembly may include a plant stripping machine, a conveyor assembly and a support frame. The plant stripping machine will be described herein to strip a hemp plant. It is understood that the plant stripping machine may be used to strip many different species of plants. The hemp stripping machine allows a user to place a hemp plant into the machine wherein the leafy biomass is removed from the stalks. The user then retracts or pulls the stalk/stem portion upward from the machine while the stripped leafy biomass drops onto a conveyor belt which transports it for further processing. 
       FIG. 1  and  FIG. 2  illustrate the hemp stripping assembly shown in perspective views. Hemp stripping machine  10  may include an elongated casing having two ends including, a pair of motor covers  30  and a pair of opposing central ramp portions  40  forming a top side of the casing and terminating at a longitudinal entry slot  48 . The casing defines an interior volume for containing and somewhat directing the free leafy biomass. The casing may further include indented sides  43  to prevent accumulation of the free leafy biomass within machine  10  and help direct the free leafy biomass out of machine  10 . The floor of the machine is either open or forms a ramp leading to an exit opening arranged optionally yet preferably over a conveyor assembly  110 . 
     The machine  10  may be arranged over conveyor assembly  110  by supporting frame pieces positioned at both ends of the elongated case. Any number of frame pieces may be used to support machine  10 . In some examples two frame pieces are used. In the illustrated embodiment, each frame piece may include a cross brace  16  and a pair of legs  14 . Cross brace  16  may be an elongated body with two ends positioned horizontal in relation to the ground. Each leg  14  extends toward the ground from opposing ends of cross brace  16 . In some examples, the legs may include a triangular shaped base with an upright beam extending from the base of the triangle to the apex of the triangle. The legs may be adjusted to any desired working height. 
     Conveyor assembly  110  may include belt  120  and frame  112  with legs  114 . Belt  120  may be any suitable conveyor belt providing for a continuous loop of a sheet material around rollers on the frame of the conveyor assembly. The belt may be a continuous surface or composed of woven fibers of any suitable sheet material, for example thermoplastics, metal, rubber, fabric or leather. 
     Frame  112  may be in the shape of an elongated rectangle. Frame  112  may incorporate various numbers of legs  114  for support. In some embodiments, the frame includes three legs  114 . Legs  114  may include two vertical beams parallel to each other on opposing lateral sides of frame  112 . Cross-beams may be mounted extending between the vertical beams and perpendicular to the vertical beams. The cross-beams may also be parallel to each other. The frame  112  and legs  114  may be made of any suitable material, for example a metal or plastic. 
       FIG. 2  illustrates an embodiment with the hemp stripping machine  10  angled toward one side of conveyor assembly  110 . This configuration permits easier access for a user on one side of the assembly to place a hemp plant into the hemp stripping machine. 
       FIGS. 3-7  illustrate views of hemp stripping machine  10  without the supporting frames and conveyor assembly  110 . As illustrated, each opposing ramp portion  40  of casing includes a vertical outer side surface  42  ending at an upper edge where it transitions to top ramp  44 . Top ramp  44  slopes diagonally inward and terminates at edge  46 . The two ramp portions mirror each other resulting in a gap G 1  between opposing parallel edges  46 . The gap G 1  defines entry slot  48 . Ramp portions  44  may be in other geometries still defining an interior volume for containing and somewhat directing the free leafy biomass. 
     The casing may optionally include inner plates  32  to separate and protect motors positioned at the ends of the casing. For instance, plates  32  help prevent free leafy biomass from clogging the motors. 
       FIG. 6  and  FIG. 7  illustrate a bottom view and a perspective bottom view of machine  10 . As illustrated, arranged longitudinally below the respective ramp portions are a pair of rotating stripping assemblies  50  (shown in  FIG. 9 ). As described in further detail below, each stripping assembly includes a shaft  51 . A plurality of stripping members  60  extend radially and are spaced along the length of the shafts  51 . In some examples, the stripping members  60  extend in only one direction from the shaft  51 . In other examples, the stripping members  60  are arranged in pairs spaced 180 degrees around the circumference of the shaft  51 . Each shaft  51  is rotationally driven by one or more power sources housed in one or more of the machine ends. In some examples, the one or more power sources is a power of motors  54 . Each motor  54  is operably configured to independently rotate one of the shafts. The motor may be an AC motor. In additional embodiments, the motor may include a variable frequency drive for varying the motor input frequency and voltage to an AC motor. 
     The shafts  51  are spaced apart defining gap G 2  between them. The shafts  51  are arranged below entry slot  48 . The stripping members  60  radially overlap yet are longitudinally offset to alternate with each other, preventing them from hitting each other or the opposing shaft  51  while in use. The stripping members  60  extend from the pair of shafts  51  a radial distance sufficient to overlap within the gap G 2 . In some examples, the stripping members  60  may extend from the shafts  51  a distance equal to or greater than half the width of the gap G 2 . During operation, the shafts  51  counter rotate in relation to the other shaft so that the stripping members  60  pull material downward between the two shafts and rotate upward on the outward sides. 
     Stripping members  60  may be elongated fibers with their distal ends extending from the shaft  51 . Stripping members  60  are somewhat rigid, yet stripping members  60  are also flexible enough that during operation of the machine, they may flail and strip a hemp stalk of leafy biomass without breaking off pieces of the hemp stalk. The stripping members  60  are preferably made of slightly flexible materials such as nylon forming a nylon cord. In another embodiment, the stripping members may be made of a rigid metal tine mounted to shaft  51  by a rubber boot allowing the metal stripping member to move/flail within the rubber mount. In other examples, the stripping members  60  may be composed of any composition of suitable materials, for example a rubber or a nylon/polyester blend. Stripping members can be solid or hollow. 
       FIGS. 6 and 7  provide the detailed views of frame  20  of hemp stripping machine  10 . The perimeter of frame  20  may include a pair of side bars  22  and a pair of end plates  24 . Each side bar  22  includes two ends. The side bars  22  may be arranged parallel in relation to each other. End plates  24  are mounted to and extend between the ends of both side bars  22 . Frame  20  may optionally be in a generally rectangular shape. Each end plate  24  may include support holes  25  that allow machine  10  to be tilted along its longitudinal axis and selectively secured at an angled orientation. 
     Frame  20  may further include motor mounts  26  and bearing mounts  28 . In some examples, the motor mounts  26  and bearing mounts  28  are secured to and extend between side bars  22 . The motor mounts  26  and bearing mounts  28  may be secured using fasteners or welding. A motor mount  26  may be utilized to secure a motor  54  into position. Bearing mounts  28  may be utilized to secure pillow blocks  29  (illustrated in  FIG. 8 ) in a position. Each pillow block  29  may contain a bearing with one of several types of rolling elements, including ball bearings, a cylindrical roller, a spherical roller, a tapered roller, or a metallic or synthetic bushing. 
     Frame  20  further defines an opening  70  in the floor of the machine. More specifically the perimeter of the opening  70  may be defined by side bars  22  and bearing mounts  28 . During operation, when the leafy biomass is stripped off of the stalk by the stripping members  60 , the leafy biomass drops through opening  70  and on to conveyor assembly  110 . 
       FIG. 8  illustrates hemp stripping machine  10  with the pair of covers  30  and the pair of ramp portions  40  removed.  FIG. 9  illustrates a stripping assembly  50  removed from the rest of the machine. Stripping assembly  50  includes shaft  51 , motor  54 , coupling  53  and a pair of pillow blocks  29 . As described above, shaft  51  includes stripping members  60 . Shaft  51  further includes a proximal end  55 , central portion  56  and distal end  57 . Proximal end  55  and distal end  57  of shaft  51  each extend through a respective pillow block  29  to rotatably mount the shaft in place. Proximal end  55  of shaft  51  extends through pillow block  29  and engages the drive shaft of motor  54  via coupling  53 . Motor  54  is used to rotate shaft  51  around its longitudinal axis during operation of machine  10 . 
       FIG. 10  provides an enlarged view of a portion of a shaft  51  with stripping members  60  extending radially along the length of the shaft. In other examples, stripping members  60  may extend along only a portion of shaft  51 , for example along 75%, 50% or 25% of the shaft length. 
       FIG. 11A  and  FIG. 11B  illustrate cross-sectional views of two examples of shaft  51 . As illustrated in  FIG. 11A  shaft  51  may include openings  62 , sleeves  64  and set screws  66 . In the illustrated example, shaft  51  is a solid pipe with sleeves  64  extending across the interior diameter of shaft  51 . Stripping members  60  may be extended through sleeve  64 . Set screws  66  may be used to secure sleeves  64  and/or stripping members  60  within the shaft  51 . The stripping members  60  are demonstrated as each formed of a single elongated fiber or bundle of fibers protruding radially from opposing ends of sleeve  64 . The ends of stripping member  60  may extend 180 degrees from each other. Stripping members  60  possess enough rigidity to be linearly fed through the sleeves during the manufacturing of the machine or during replacement of damaged stripping members. In another example, in addition to or in replacement of the stripping members  60  extending through sleeve  64 , stripping members  60  and sleeves  64  may extend through openings  62 . This arrangement may result in stripping members in 90 degree increments around the circumference of shaft  51 . 
       FIG. 11B  illustrates an alternate embodiment of a cross-section of shaft  51 . Stripping members  60 ′ extend through the openings in shaft  51 . In this example, the stripping members  60 ′ do not extend through the entirety of the shafts interior. The base end of each stripping member is mounted to the shaft using a mounting back  64 ′ in the interior of the shaft. Various techniques may be used to secure the base of the stripping members  60 ′ to the mounting back  64 ′. In one embodiment, mounting back  64 ′ may be threaded to engage with threads on the base of the stripping members  60 ′. In yet another embodiment, mounting back  64 ′ may be a one way clamp with angled flanges preventing the stripping member from being pulled out of the mounting back  64 ′. In other alternatives, a friction fit, crimping or a variety of adhesives may be utilized to fasten the stripping member  60 ′ to the mounting back  64 ′. 
       FIGS. 12-13  illustrate another example of a shaft  151 . Shaft  151  is comparable to shaft  51 . The differences between shaft  151  and shaft  51  are discussed below in reference to shaft  151 . Shaft  151  may include a shaft body  152 , one or more elongated plates  158  and one or more stripping member components  161 . 
     Shaft body  152  may define one or more indented portions or grooves  159 . The indented portions  159  may extend along the entire length of the shaft body surface. Each indented portion  159  may be defined by a flat base  153  with diverging sides  155  broadly in the shape of the letter “U”. In some examples, the shaft body includes a pair of indented portions  159 . The pair of indented portions  159  may be positioned 180 degrees apart around the circumference of the shaft body  152 . 
     Each stripping member component  161  may be a single sheet of material defined by a center portion  163  with a pair of side edges  165 . A plurality of stripping members  160  may extend away from the center portion  163  as fibers from the pair of side edges  165 . The stripping members  160  may be cut from a single sheet of material. In some examples, the single sheet of material is flexible. In an alternative example, each stripping member  160  may be attached to the side edges  165  of the stripping member component  161 . The stripping members  160  may be spaced evenly apart along the length of the stripping member component  161  or may be spaced in desired patterns or otherwise. Stripping members  160  are comparable to stripping members  60 . 
     When clamped within the indented portion  159 , the stripping member component  161  may be folded into substantially the same U-shape as the indented portion  159 . When in the folded configuration, the side edges  165  allow the stripping member component  161  to be nested within the indented portion  159  of the shaft body and below the shaft surface. The folded configuration of the stripping member component  161  may cause the stripping members  160  to diverge outward and up in relation to each other. When mounted in the indented portion  159  of the shaft body  152 , a plurality of openings in the base of the stripping member component  161  are aligned with the plurality of openings in the shaft body  152 . 
     One or more plates  158  may include a flat upper surface and a bottom surface to nest within the indented portion  159  of the shaft body  152 . In some examples, the upper surface of each plate is mounted flush with the outer surface of the shaft body  152 . Plate  158  may include a plurality of fastener openings. 
     When assembled, the stripping member assembly  161  is securely sandwiched between the indented portion  159  of the shaft body  152  and one or more plates  158 . When assembled, openings of the shaft body  152 , stripping member component  161  and plate  158  are aligned, allowing fasteners, such as threaded screws or bolts, to extend downward through the plate  158 , stripping member component  161  and shaft body  152 , securing the pieces together. Various other known techniques, such as welding or adhesives, may be used to secure the plate  158 , stripping member assembly  161  and shaft body  152  together. 
     Each indented portion  159  of shaft body  152  may receive one stripping component  161  and one plate  158 . In alternative embodiments, any number of stripping components  161  and plates  158  may be received along the length of the indented portion  159 . As illustrated in FIG.  12 , each indented portion  159  may receive, along its length two plates  158 . As described above, the stripping members may extend along only a portion of shaft  151 , for example along 75%, 50% or 25% of the shaft length. 
     A technique for stripping hemp stalks of leafy biomass with the hemp stripping machine will now be described. During operation, the user may feed the hemp plant through the entry slot, inserting the stalks and leafy biomass between the shafts. As the stalks pass between the shafts, the stripping elements flail against the stalk, stripping the leafy biomass from the stalks and pulling the leafy biomass downward while leaving the stalks intact. The user then retracts the stalks against the pull of the stripping elements, while they continue to flail, further ensuring that the stalks are completely stripped. The stalks may then be collected for further processing. Concurrently, the leafy biomass falls through the opening in the floor of the machine, for instance onto a conveyor assembly. The leafy biomass passes to the end of the conveyor assembly where it can be collected and transferred for further processing. 
     The language describing the sides, surfaces and tops and bottoms of the disclosures components is not intended to be limiting in any manner. The language is solely included to aid in the understanding of the disclosure. 
     While the disclosure has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes, equivalents, and modifications that come within the spirit of the disclosure defined by the following claims are desired to be protected.