Abstract:
A grain threshing device ( 10 ) comprising a receptacle ( 12 ) or receiving a portion of crop head. The receptacle ( 12 ) has a plurality of longitudinal ribs ( 30 ) on inner surfaces. One or more flexible arm members ( 28 ) are arranged on a rotating shaft ( 22 ) within the receptacle ( 12 ) such that the flexible arm members ( 28 ) strike the ribs ( 30 ) during rotation. The action of the flexible arm members ( 28 ) and ribs ( 30 ) on the crop head within the receptacle ( 12 ) separates the grain from the crop head.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a grain threshing device.  
         [0002]     Various types of machinery are used for the purpose of threshing grain. A known problem which many types of such machinery is that due to the mechanical arrangement of the threshing apparatus, the grain can be cracked during the threshing process.  
         [0003]     Also, it is often necessary in the production of grain crops to extract small quantities of grain before harvest in order to have them tested. The testing process provides information on a range of characteristics of the grain and is used to determine the value of the crop. However, as the equipment available to extract grain is generally in the form of heavy machinery designed to extract the grain in large quantities, it is therefore relatively inefficient to move this equipment between a number of crops to extract the small amount of grain required for testing purposes.  
         [0004]     The present invention provides an improved device for threshing grain and a portable grain thresher utilising the improved device.  
       SUMMARY OF THE INVENTION  
       [0005]     In accordance with one aspect of the present invention there is provided a grain threshing device comprising:  
         [0006]     a receptacle arranged to receive a portion of crop head, the receptacle having a plurality of longitudinal ribs on inner surfaces thereof;  
         [0007]     a shaft rotatably mounted within the receptacle; and  
         [0008]     one or more flexible arm members extending from the shaft, the arm members being arranged to strike the longitudinal ribs upon rotation of the shaft;  
         [0009]     wherein rotation of the shaft and the flexible arm members causes the arm members to strike the crop head in the receptacle to separate the grain from the crop head.  
         [0010]     In accordance with a second aspect of the present invention there is provided a portable grain thresher comprising:  
         [0011]     a portable receptacle arranged to receive a portion of crop head, the receptacle having a plurality of longitudinal ribs on inner surfaces thereof;  
         [0012]     a shaft rotatably mounted within the receptacle, the shaft having an end thereof engageable with a portable drive means; and  
         [0013]     one or more flexible arm members extending from the shaft, the arm members being arranged to strike the longitudinal ribs upon rotation of the shaft;  
         [0014]     wherein the portable drive means causes rotation of the shaft and the arm members such that the arm members strike the crop head in the receptacle to separate the grain from the crop head. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]     The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:  
         [0016]      FIG. 1  is an upper perspective view of a grain threshing device in accordance with the present invention with a portion of the vessel cut away;  
         [0017]      FIG. 2  is an upper perspective view of a portable grain thresher in accordance with the second aspect of the present invention with a portion of the vessel cut away;  
         [0018]      FIG. 3  is an upper perspective of an alternative embodiment of a portable grain thresher in accordance with the second aspect of the present invention with a portion of the vessel cut away; and  
         [0019]      FIG. 4  is an exploded view of the portable grain thresher of  FIG. 3 .  
     
    
     DESCRIPTION OF THE INVENTION  
       [0020]     Referring to  FIG. 1 , there is shown a grain threshing device  10 . The grain threshing device  10  comprises a receptacle  12  in the form of a cylindrical vessel  14 . The cylindrical vessel  14  includes a first end  18  through which grain crop head may be received and a suitably sized mesh  24  across an open second end  20 .  
         [0021]     The grain threshing device  10  includes a rotatably mounted shaft  22  arranged to extend along a central longitudinal axis of the cylindrical vessel  14  from the first end  18  to the second end  20 .  
         [0022]     The shaft  22  is provided with a mounting means  16  for securing a plurality of flexible arm members  28  to the shaft  22 . The mounting means  16  comprises an elongate member  17  having a longitudinal bore  19  to receive the shaft  22 . The elongate member  17  includes a plurality of transversely extending portions  29 . The transversely extending portions  29  are arranged in pairs such that the pairs of transversely extending portions  29  extend outwardly from opposed sides of the elongate member  17 . The transversely extending portions may be arranged such that each pair of transversely extending portions  29  are angularly offset from adjacent pairs of transversely extending portions  29  on the shaft  22 . Each arm member  28  is secured to one of the transversely extending portions  29  such that the arm members  28  are arranged to extend transversely to the shaft member  22 . The arm members  28  are in the form of flat elongate strips constructed of a flexible material such as rubber and are secured to the transversely extending portions  29  by any suitable means, such as by bolts  40  provided adjacent outer ends of the transversely extending portions  29  as shown in  FIG. 1 .  
         [0023]     The cylindrical vessel  14  is also provided with a plurality of inwardly protruding ribs  30 . The inwardly protruding ribs  30  are arranged longitudinally at regular angular intervals around the inner surface of the cylindrical vessel  14 . The arrangement of the inwardly protruding ribs  30  and the arm members  28  is such that outer ends of the arm members  28  strike the inwardly protruding ribs  30  when the shaft  22  is rotated. The ribs  30  in the embodiment shown have a generally triangular transverse cross section.  
         [0024]     The shaft  22  is arranged to be engageable with a drive means (not shown). The drive means may be any device suitable for rotating the shaft  22 .  
         [0025]     The mesh  24  may also be removable from the cylindrical vessel  14  so that different sized mesh  24  may be used for different grain crops.  
         [0026]     A collecting vessel (not shown in  FIG. 1 ) is provided below the mesh  24  to collect the separated grain.  
         [0027]     FIGS.  2  to  4  show a portable threshing device  10  in accordance with the invention where like numerals denote like parts.  
         [0028]     The cylindrical vessel  14  of the portable grain thresher  10  comprises a receptacle  12  which is constructed to be of a size and weight such that it can be easily carried to various locations at which a sample of crop needs to be extracted. The receptacle  12  has a removable lid  26  at the first end  18 .  
         [0029]     A first end of the shaft  22  is arranged to extend through a hole  27  provided in the lid  26 , when the lid  26  is secured to the cylindrical vessel  14 . The shaft  22  is rotatably secured adjacent a second end thereof within a suitably sized aperture provided within the mesh  24 .  
         [0030]     The arm members  28  are secured directly to the shaft  22  in the embodiment shown in  FIG. 2  by securing means  29  and are angularly offset relative to each other. In the embodiment shown in  FIGS. 3 and 4 , the arm members  28  are secured to a mounting means  16  mounted on the shaft  22 . The mounting means  16  is in the form of a rectangular plate member  38 . The arm members  28  are secured to a surface of the rectangular plate member  38  by bolts  40 .  
         [0031]     The second end of the shaft  22  is arranged to be engageable with a portable drive means (not shown). The portable drive means may be in the form of a cordless drill. The second end  20  of the cylindrical vessel  14  may also be provided with a narrowed portion  32 . The narrowed portion  32  is arranged such that it may be received within a collecting vessel  36  as shown in  FIG. 3 . The narrowed portion  32  and an upper edge of the collection vessel  36  are preferably provided with locking means  42  so that the vessel  14  may be secured to the collection vessel  36  in use.  
         [0032]     In use, crop head is removed and placed into the cylindrical vessel  14 . The drive means is secured to the first end of the shaft  22  and activated to rotate the shaft  22  and the flexible arm members  28 . The action of the flexible arm members  28  striking the crop head and the ribs  30  act to thresh the crop head. The separated grain then falls through the mesh  24  and into the collecting vessel. Any chaff which is small enough to pass through the mesh  24  can be removed by pouring the grain and chaff from the collecting vessel into a further vessel and allowing the wind to blow away the lighter chaff.  
         [0033]     Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention