Abstract:
A shredder has a pair of plates with interdigitated teeth that can be relatively rotated for shredding vegetative material. A receptacle mounted in a housing can hold vegetative material shed from a location between the pair of plates. A screen in the receptacle can separate fine material and store it at a relatively low position for later usage. A weighing device mounted at the housing can weigh vegetative material in the receptacle.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to apparatus and methods for shredding, grinding, comminuting and weighing vegetative material. 
         [0003]    2. Description of Related Art 
         [0004]    Herbs, tobacco and other vegetative material will often be shred or ground just before being used, in order to assure freshness of the shredded/ground material. In this specification methods and apparatus for grinding and comminuting are deemed to include methods and apparatus for shredding. 
         [0005]    Often users will want to screen ground or shredded material and separate it into fine and coarser materials that have different properties and usefulness. 
         [0006]    Measuring the amount of shredded/ground material is also important to assure that a sufficient amount of the material has been prepared. On the other hand, one ought to avoid preparing an excessive amount. While the excess might be stored for later use, this material will tend to quickly lose moisture and freshness and thus become unsatisfactory. 
         [0007]    While food processors, blenders and other devices can comminute vegetative material, they tend to be large and occupy significant storage space. Likewise many weighing devices exist but these can again be bulky. Sifters exist but these are not easily used to separate comminuted material in a desirable manner. In addition, finding storage space for a separate grinder/shredder, sifter, and weighing device can often be difficult. Moreover, often one would like to be able to easily transport these devices and use them in situations where electricity or other external power sources are unavailable. 
         [0008]    Known weighing devices have zeroing features. For example, a container may be placed on a scale before using a zeroing or tare function. Basically, the weight of the container is eliminated and the displayed weight is compensated to indicate only the weight of the contents of the container. 
         [0009]    See also U.S. Pat. Nos. 3,721,361; 3,858,815; 4,003,166; 4,111,212; 4,304,363; 4,538,355; 4,605,175; 4,789,106; 4,858,709; 5,174,403; 5,329,069; 5,386,944; 5,522,556; 5,603,458; 6,736,342; 6,775,919; 6,834,817; 7,422,170; 7,422,170; 7,422,170; 8,393,563; and 8,733,679; as well as US Patent Application Publication Nos. 2011/0147504; 2012/0259336; and 2014/0261471; 
       SUMMARY OF THE INVENTION 
       [0010]    In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a shredder for shredding vegetative material. The shredder has a housing and a first plate mounted at the housing. The first plate has a working face with a first plurality of teeth. The shredder also has a second plate with an opposing face. This opposing face has a second plurality of teeth interdigitated with the first plurality of teeth. The first plate and the second plate are relatively rotatable for shredding the vegetative material. Also included is a receptacle mounted in the housing for holding vegetative material shed from a location between the first and the second plate. The shredder also has a weighing device mounted at the housing for weighing vegetative material shed from a location between the first and the second plate 
         [0011]    According to another aspect of the present invention, there is provided a method for shredding vegetative material. The method employs a weighing device, a receptacle, and a pair of plates with interdigitated teeth. The method includes the step of placing vegetative material between the pair of plates. The pair of plates are relatively rotated to interdigitate their teeth and shred the vegetative material. The method also includes the step of delivering vegetative material shredded by the teeth of the pair of plates to the receptacle. Another step is screening vegetative material in the receptacle to separate fine material and store it at a relatively low position for later usage. The method also includes the step of weighing vegetative material in the receptacle with the weighing device. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of illustrative embodiments in accordance with the present invention when taken in conjunction with the accompanying drawings, wherein: 
           [0013]      FIG. 1  is an exploded, perspective view of a shredder/grinder with its access door open to receive a receptacle, in accordance with principles of the present invention. 
           [0014]      FIG. 2  is a perspective view of the holder of  FIG. 1 ; 
           [0015]      FIG. 3  is an elevational view of the holder of  FIG. 2 ; 
           [0016]      FIG. 4  is a plan view of the working face of a first plate of  FIG. 1 ; 
           [0017]      FIG. 5  is a plan view of the opposing face of a second plate of  FIG. 1 ; 
           [0018]      FIG. 6  is an exploded view of the access door and dispensing door of  FIG. 1 ; 
           [0019]      FIG. 7  is a top view of the weighing device of  FIG. 1 ; 
           [0020]      FIG. 8  is an exploded view of a receptacle that is to be installed in the arrangement of  FIG. 1 ; 
           [0021]      FIG. 9  is an assembled view of the apparatus of  FIGS. 1 and 6  showing the receptacle about to be installed in the housing and with the access door removed from the housing for simplification purposes; 
           [0022]      FIG. 10  is a detailed, fragmentary, perspective view of the alignment stub at the top center of the device of  FIG. 7 ; 
           [0023]      FIG. 11  is a bottom view of the alignment stub of  FIG. 10 ; 
           [0024]      FIG. 12  is a side view of the stub of  FIG. 10 ; and 
           [0025]      FIG. 13  is detailed, fragmentary, perspective view of a socket in the bottom of the receptacle of  FIG. 8 . 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    Referring to  FIG. 1 , the illustrated apparatus is part of a shredder and includes a weighing device  10  having a protruding control panel  12 A. Device  10  has a weighing platform  10 A. 
         [0027]    Housing  32  has a generally cylindrical shape and has a skirt  32 A that fits around weighing platform  10 , extending about 180°. Skirt  32 A can be secured in place by screws (shown hereinafter), which are inserted through a number of screw holes  32 B. The upper mouth of housing  32  has internal threads  32 C. 
         [0028]    The back of housing  32  has a door opening bordered on top by lintel  32 D and on the bottom by sill  32 E. The right and left vertical edges of this opening are angularly spaced by about 180° with the right edge having a pair of magnets  32 H (one visible in this view) and a pair of hinge knuckles  32 F. 
         [0029]    Holder  34  is a cylindrical sleeve with screw holes  34 E. Holder  34  has flange  34 A located above externally threaded collar  34 C, which collar can be threaded into internal threads  32 C of housing  32 . Holder  34  has a number of equiangularly spaced ridges  34 D. 
         [0030]    First plate  36  is shown as a circular disk with eight peripheral notches  38  that are designed to slide over ridges  34 D in holder  34 . Plate  36  can be secured in place in holder by means of screws (net shown) threaded into screw holes  34 E. A first plurality of teeth  40  in the form of four sided prisms, project perpendicularly from the upper working face of plate  36 . A similarly projecting center hub  43  is slightly taller than teeth  40 . 
         [0031]    Second plate  54  has the same thickness and outside diameter as plate  36  but lacks notches. In this embodiment plates  36  and  54  each have a diameter of 2.5 inches (6.3 cm) and a thickness of 0.09 inch (2.3 mm), although different dimensions may be employed in other embodiments. 
         [0032]    A second plurality of teeth  58  in the form of four sided prisms project perpendicularly from the lower opposing face of plate  54 . Teeth  58  are herein referred to as a second plurality of teeth in second plate  54 . 
         [0033]    Cup-shaped cover  64  is shaped to receive plate  54 , which is glued in place. Consequently, the turning of cover  64  will cause plate  54  to rotate. 
         [0034]    Referring to  FIGS. 2 and 3 , previously mentioned ridges  34 D on the inside of holder  34  are located above chute  34 B. Chute  34 B has a funnel-like shape that and projects beyond external threads  34 C. 
         [0035]    Referring to  FIG. 4 , previously mentioned plate  36  is shown as a circular disk with eight peripheral notches  38 . Teeth  40  are arranged in three evenly spaced, circular, concentric rows, namely (1) an outer annular row having sixteen equiangularly spaced teeth  40 ; (2) a middle annular row having eight equiangularly spaced teeth  40 ; and (3) an inner annular row having four equiangularly spaced teeth  40 . For each row, teeth  40  have a consistent radial placement 
         [0036]    Each of the teeth  40  have four sides: an inside, an outside, a clockwise facing side, and a counterclockwise facing side. The clockwise and counterclockwise facing sides are concave and form acute cutting edges at a cutting angle of about 35°, although different angles may be employed in other embodiments. 
         [0037]    Plate  36  also has through holes  44  arranged in three circular, concentric rows as follows: (1) an outer annular row having twenty four spaced holes  44  arranged in eight equiangularly spaced trios, a trio being located between each adjacent pair of notches  38 ; (2) a middle annular row having sixteen equiangularly spaced holes  44 , specifically eight small holes alternating with eight larger holes; and (3) an inner annular row having eight angularly spaced holes  44 . 
         [0038]    Hub  43  is a prismatic column having a star-shaped cross-section. Hub  43  is located at the center and has an embedded central magnet  43 A. 
         [0039]    Referring to  FIG. 5 , previously mentioned plate  54  is shown as a circular disk with a central, flush, embedded magnet  52 , and upright teeth  58 . Teeth  58  are arranged in three evenly spaced, circular, concentric rows, namely (1) an outer annular row having eighteen equiangularly spaced teeth  58 ; (2) a middle annular row having twelve equiangularly spaced teeth  58 ; and (3) an inner annular row having six equiangularly spaced teeth  58 . For each row the teeth  58  have a consistent radial placement and the rows are spaced so they can pass by or between the previously mentioned rows of teeth (teeth  40  of  FIG. 4 ). Moreover, the three rows of teeth  58  have a radial spacing that allows them to pass over holes  44  of  FIG. 4 . 
         [0040]    Teeth  58  have a shape similar to teeth  40 , but appear as mirror images when assembled and viewed along the same vertical direction. Teeth  40  and  58  may be arranged similarly to those shown in U.S. Pat. No. 8,733,679, which is incorporated herein by reference. 
         [0041]    In this embodiment teeth  40  and  58  are 0.35 inch (9 mm) tall and have a thickness in the radial direction of 0.09 inch (2.3 mm), although different dimensions may be employed in other embodiments. 
         [0042]    Referring to  FIG. 6 , access door  33  is shown as an arcuate panel with a central opening bordered by outwardly protruding lentil  33 B, outwardly protruding sill  33 C, outwardly protruding left jamb  33 D, and right jamb  33 E. Dispensing door  35  has a right rib  35 A that can be hinged using hinge pins (not shown) between elements  33 B and  33 C, next to right jamb  33 E. Dispensing door  35  has a stop  35 B with a pair of inwardly facing latching elements (magnets  35 M of  FIG. 1 ) that can latch onto magnets  33 M on jamb  33 D of access door  33  to hold dispensing door  35  closed. 
         [0043]    Dispensing door  35  has a magnet  35 N embedded on the sloping face of external abutment  35 E. Magnet  33 N is embedded on the sloping face of external abutment  33 F, which is located next to jamb  33 E of access door  33 . When dispensing door is swung open fully, magnets  33 N and  35 N act as latching elements for holding dispensing door  35  open. 
         [0044]    Access door  33  has a rail  33 G that is hinged between knuckles on the housing (i.e., knuckles  32 F of housing  32  in  FIG. 1 ). Rail  33 G can be hinged by means of hinge pins (not shown). A finger grip  33 A molded into the swinging end  33 H of access door  33  has a sloped surface rising from a recessed distal end to a prominent proximal end. 
         [0045]    A pair of magnets  33 J are embedded on the inside of access door  33  at swinging end  33 H, at a higher elevation than finger grip  33 A. Magnets  33 J act as closure elements that can latch onto housing magnets (see the magnet  32 H visible in  FIG. 1 ) to hold access door  33  closed. This relatively high elevation of magnets  32 H and  33 J avoids magnetic interference with the weighing device  10  ( FIG. 1 ). 
         [0046]    Referring to  FIG. 7 , previously mentioned weighing device  10  has a weighing platform  10 A and control panel  12 A. Panel  12 A has an LCD display  22  between a pair of control buttons  23 . Device  10  has an internal transducer (not shown) such as a piezoelectric component or other element that may be used as a weighing transducer. 
         [0047]    Buttons  23  may be operated in a conventional manner to turn device  10  on and off. Buttons  23  may also be used to perform a zeroing function. For example, if an object currently resting on platform  10 A is simply a container that should not be counted as a payload, device  10  can record that container weight and subtract it from future weighings. 
         [0048]    Referring to  FIGS. 8 and 9 , receptacle  80  includes basket  86  that is a hollow cylinder, except for a spout  86 A. Screen  84  is glued in place inside basket  86  just below spout  86 A. In this embodiment screen  84  was an 80 grit screen, although good results are achieved with screens in the range 50 to 120 grit. In any event, the fineness of the screen will be chosen depending on the material being graded and the desired grading. 
         [0049]    Split sleeve  82  is slid down into the open top of basket  86  until upper flange  82 A rests on the basket&#39;s rim. The split in sleeve  82  is aligned with spout  82 A and encompasses about 45°. 
         [0050]    A subjacent receiver  88  is shown as shallow cup with an externally threaded collar  88 A rising from base  88 B. The bottom of basket  86  has internal threads (not shown) for receiving threaded collar  88 A, so that receiver  88  threadably removable and threadably installable. 
         [0051]    Referring to  FIGS. 7 and 10-12 , alignment stub  70  is attached to the center of weighing platform  10 A. Stub  70  is a discrete plastic element attached by gluing, although in other embodiments the stub may be made from any of a variety of materials and may be fastened in various ways; or may be an integral feature of platform  10 A. 
         [0052]    Stub  70  is for the most part a solid polyhedron with a central rectangular block section  70 A located between pyramidical sections  70 B and  70 C. Pyramidical sections  70 A and  70 B each have an upper sloped surface and an opposing pair of converging side faces that are vertical (i.e., perpendicular to the surface of weighing platform  10 A). The exposed side faces of block section  70 A are also vertical. 
         [0053]    Block section  70 A has a through bore  70 D for receiving magnet  72 , which acts as a holding element. The underside of stub  70  has four equiangularly spaced grooves  70 E extending radially from bore  70 D to the edge of stub  70  to permit discharge of excess glue used to secure the underside of stub  70  to platform  10 A. 
         [0054]    In this embodiment stub  70  has an overall length of 0.91 inches (2.3 cm), an overall width of 0.38 inches (0.96 cm), and an overall thickness of 0.07 inches (1.8 mm), while the separation between sections  70 A and  70 B (i.e, the length of block section  70 A) is 0.245 inches (0.62 cm). It will be appreciated that different dimensions may be used in other embodiments. 
         [0055]    Referring to  FIG. 13 , the underside of receiver  88  has a socket  74  that is shaped to match the surface of previously mentioned stub  70  of  FIG. 10 . Specifically, socket  74  has a rectangular concavity  74 A between pyramidical concavities  74 B and  74 C. The center of concavity  74 A has a hole  76  into which magnet  78  is embedded, flush. 
         [0056]    Stub  70  and socket  74  have vertical sides that reduces the likelihood of an applied torque causing the stub or socket to ride over each other and disconnect. Also, this verticality and close tolerances reduces play and increases the accuracy of the arrangement. 
         [0057]    To facilitate an understanding of the principles associated with the foregoing apparatus, its operation will be briefly described. The shredder is assembled as shown in  FIG. 9 , but with doors  33  and  35  installed as shown in  FIG. 1 . The receptacle  80  is also assembled as shown in  FIG. 9 . 
         [0058]    Receiver  88  is screwed onto basket  86  until its alignment mark  88 C lines up with the basket&#39;s alignment indicia  86 B. Receptacle  80  will then be installed inside housing  32 . The alignment of marks  86 B and  88 C ensure that socket  74  ( FIG. 13 ) on the underside of receiver  88  is so oriented that when stub  70  lands in the socket, spout  86 A is centered in the opening of housing  32 . Therefore, when access door  33  ( FIG. 1 ) is closed, spout  86 A will be centered between jambs  33 D and  33 E ( FIG. 6 ) associated with dispensing door  35 . 
         [0059]    In fact, when positioning receptacle  80  so that stub  70  and socket  74  will mate, the sloping surfaces  70 B and  70 C of the stub will produce a camming action that will tend to rotate the receptacle into the correct orientation. Also, magnets  72  and  78  will draw stub  70  and socket  74  together, further fostering proper orientation. With the device assembled in this manner, the user may close doors  33  and  35 . 
         [0060]    The user may place weighing device  10  on a tabletop or other horizontal surface. Buttons  23  ( FIG. 7 ) are then operated to turn device  10  on and request a zeroing routine. In response, device  10  will capture the value indicating the weight on platform  10 A, which is essentially the weight of receptacle  80 . That captured value will be stored as a baseline. Device  10  will then send a signal to display  22 , which will indicate a zero reading. 
         [0061]    Next the user will remove cover  64  and the attached plate  54 . The user will then insert vegetative material atop plate  36 . This vegetative material may be herbs, tobacco, or the like. Cover  64  and plate  54  are now depressed until magnet  52  of plate  54  snaps into magnetic engagement with magnet  43 A of plate  36 . 
         [0062]    When plate  54  was snapped onto plate  36 , teeth  58  were thrust downwardly to interdigitate with teeth  40 . With this downward movement vegetative material will be caught between teeth  40  and  58 , stretched and partially torn or shredded. The shredding process can now begin in earnest as the user grasps housing  32  with one hand and cover  64  with the other hand. By rotating cover  64  relative to housing  32 , the user will cause plate  54  to rotate relative to plate  36 . 
         [0063]    If cover  64  is rotated relative to housing  32 , teeth  58  will move relative to teeth  40 . Consequently, vegetative material will be caught between teeth  58  and  40 , stretched, and shredded. In some cases the relative rotation will be reversed. This may occur because of user preferences, or because the user angularly oscillates plate  54  relative to plate  36 . 
         [0064]    Stub  70  will keep receptacle  80  centered and away from the inside surfaces of housing  32 . This will avoid receptacle  80  rising and interacting with the shredding process, which would adversely affect the accuracy of the weighing process. In addition, stub  70  will fit closely inside socket  74  and avoid any play that will detract from the operation of the shredder. 
         [0065]    As this process continues, vegetative material will be shredded into smaller and smaller fragments. Eventually these fragments will be small enough to fall through holes  44  in plate  36 . The shredded material is highly likely to fall through holes  44  since they are plentiful and teeth  40  and  58  tend to stir the shredded material. Also, since holes  40  and teeth  58  reside in common rows, these teeth tend to sweep shredded material into the holes  44 . 
         [0066]    After falling through holes  44 , the shredded material is guided by chute  34 B ( FIG. 2 ) into receptacle  80 . Collar  82  ( FIG. 8 ) has a wide rim that keeps shredded material from falling outside receptacle  80 . 
         [0067]    Weighing device  10  will respond to this falling material by displaying on screen  22  ( FIG. 7 ) the increasing weight. The user will observe display  22  and if the weight value is inadequate will continue to shred the material by relatively rotating cover  64  and housing  32 . 
         [0068]    In some cases, all the vegetative material between plates  36  and  54  will be shredded and discharged through holes  44 . The user will then notice the lack of resistance. In fact, because hub  43  is higher than surrounding teeth  40 , plate  54  can freewheel, with its magnet  52  spinning on magnet  43 A hub  43 . At this time the user may want to shred more vegetative material and will again remove cap  64  and plate  54  and reload the shredder as described above. 
         [0069]    Eventually, sufficient material will fall into receptacle  80  so that weighing device  10  will show on display  22  the weight value desired by the user. The user may now open dispensing door  35 , thereby releasing magnets  35 M from magnets  33 M ( FIG. 1 ). Door  35  may be swung fully open so that magnet  35 N locks onto magnet  33 N ( FIG. 6 ), keeping the door open so it will not interfere with the dispensing operation. 
         [0070]    With dispensing door  35  held open, the user may tilt the shredder so that the shredded material is dispensed by spout  86 A through door  33 . The protruding lintel  33 B and protruding sill  33 C will guide the exiting material and avoid material falling back into housing  32  to the outside of receptacle  80 . 
         [0071]    The dispensed material may either be delivered to a container or directly to an intended application. For example, if herbs were shredded, these shredded herbs may be delivered to a bowl or pot being used to prepare a dish. If tobacco was shredded, the shredded material may be directly delivered to paper that is then rolled before lighting and smoking the tobacco. 
         [0072]    When the vegetative material is shredded, certain fine material may be dislodged. For example fine plant structure such as pollen may be dislodged and will tend to fall to the bottom of receptacle  80 . Sufficiently fine material will pass through screen  84  and land in receiver  88 . In some case the user will leave the shredded material in receptacle  80 , will open access door  33 , remove receptacle  80 , and shake it to loosen fine particles, allowing them to fall through screen  84 . 
         [0073]    Whether, the vegetative material above screen  84  has been dispensed past door  35  or not, receptacle  80  can be removed and receiver  88  can be unscrewed from basket  86 . This allows the contents of receiver  88  to be immediately used or stored for later use. Thereafter, receiver  88  can be reinstalled on basket  86 . Any shredded material remaining in housing  80  can be discharged through spout  86 A, before returning receptacle  80  to housing  32 , and closing door  33 . 
         [0074]    Before putting the shredder away, a user may again lift cap  64  and plate  54  and then shake or brush out any vegetative material remaining between teeth  40  or between teeth  58 . Thereafter, plate  54  and cover  64  can be replaced in the manner described previously. 
         [0075]    At any time, one can open access door  33  in order to remove and clean receptacle  80 . Also, any loose material that missed receptacle  80  and fell into housing  32  can be swept out. 
         [0076]    Also, the foregoing equipment can be used as an independent weighing apparatus. Weighing device  10  can be zeroed as described above before removing receptacle  80 . Next, material to be weighed can be placed inside the removed receptacle  80 . Thereafter, receptacle  80  can be returned to housing  32  with socket  74  ( FIG. 13 ) placed over alignment stub  70 . Access door  33  can be dosed, but such closure is not mandatory. 
         [0077]    With receptacle  80  resting on weighing platform  10 A, weighing device  10  will weigh and display just the contents of the receptacle, because the weight of the receptacle itself will be subtracted as a result of the zeroing process. 
         [0078]    It is appreciated that various modifications may be implemented with respect to the above described embodiments. The alignment stub need not have a diamond shape with pyramidical features, but some embodiments may employ a stub with a different polyhedral shape or with some smoothly curved surfaces. In still other embodiments, multiple stubs may be employed to enhance the accuracy and stability of the placement of the receptacle. While the above teeth are shown as perpendicular, four-sided prisms, in other embodiments the teeth can be tilted, blade-like, T-shaped, extend outwardly along a curved axis, etc. Also, the number and placement of teeth can be varied depending upon the size of the device, how fine one wishes to shred material, reliability, etc. While the teeth are shown mounted on flat plates, in some embodiments the plates may be dome shaped, with a convex side of one plate facing the concave side of the other plate. In addition, the dimensions, proportions, and shapes of the various components illustrated herein may be varied depending on the desired capacity, strength, reliability, etc. In some embodiments, the disclosed screen will be replaceable to allow the user to decide how fine the screened material ought to be. In still other embodiments, multiple screens may be employed to separate the particulate into different grades of fineness. In addition the illustrated magnets may be replaced with other types of latches for holding a door open or closed. Also, depending on the requirements of strength and reliability, the shredder can be made from metal, plastics, ceramics, composite materials, etc. 
         [0079]    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.