Abstract:
A fishback assembly which is mounted on top of a separation device on an agricultural combine. The fishback assembly comprises a series of vertical fishback flanges that are coupled to one another by upstream and downstream mounting brackets. The mounting bracket is mounted to the separation device by mounting bolts passing through mounting holes formed ion the mounting brackets.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The invention is directed to a fishback assembly for use on a separation device.  
           [0003]    2. Description of the Prior Art  
           [0004]    DE-B-1,957,843 discloses a straw walker for threshers and combines, which comprises a rectangular frame and several oscillating trays. The oscillating trays have a perforated cover on their conveyance surface located on the top. The cover is held between two vertical walls having saw toothed edges. The design of these oscillating trays is such that their conveyance surface slopes upwards in the downstream direction.  
           [0005]    DE-B-1,161,073 pertains to a combine with straw walkers, onto which oscillating trays are placed which can be tilted vertically. In this manner, the conveyance surface can be placed in positions with different rising slopes, and thus the separation behavior can be modified.  
           [0006]    According to DE-A1-2,943,042, a straw walker of a combine for harvesting corn cobs is equipped with a cantilevered fishback, which extend, as cantilevered saw tooth metal sheets, over a subsequent downstream walker. That portion of the straw walker over which the fishbacks are positioned is open. Those portions of the straw walkers not having fishbacks positioned over them are provided with an apertured straw walker grid cover. These fishbacks and open straw walkers are now used for the corn. In harvesting cereal grains the fishbacks are removed and the walker is closed.  
           [0007]    Finally, the brochure “D 7000 HYDROSTATIC of Dronningborg, print code DM1059 GB 1079 3.000” shows a combine with straw walkers, over whose lengths several walker trays with different rising slopes are provided with apertured grid covers. Fishbacks formed from saw tooth metal sheet parts are placed in the middle and in the direction of conveyance onto the grid covers, which parts are to achieve an additional loosening of the material.  
         SUMMARY  
         [0008]    It is an object of the present invention to provide a fishback assembly of simple construction that can be easily manufactured.  
           [0009]    The present invention provides a fishback assembly that promotes the separation of small grains, such as cereal grain, from a crop material mat. The fishback assembly is easily mounted to a separation device, since several fishback flanges are connected to each other to form one fishback assembly. Although the present invention could be mounted to a variety of separation devices, such as, straw walkers, grain pans and/or sieves, it is particularly well suited for attachment to a straw walker and more specifically an apertured grid cover covering the straw walker trough.  
           [0010]    The fishback assembly comprises a number of fishback flanges and mounting brackets holding the fishback flanges together as a unit. The top edge of the fishback flanges is provided with a saw toothed edge. The mounting bracket has an L-shaped cross section with one of the legs of the L being provided with mounting apertures through which the mounting bolts pass. The mounting apertures are arranged to correspond to the mounting apertures used in securing straw walker grid covers to the top of a straw walker trough to simplify the mounting process.  
           [0011]    The use at the terminal end of two mounting brackets results in a higher rigidity of the fishback assembly, and it also constitutes less of an impediment to the separation process. The fishback assembly is mounted to a separation device by mounting bolts passing through holes located in the mounting brackets, thereby providing a user-friendly operation.  
           [0012]    If the mounting brackets, like the fishback flanges, are designed in the same manner, high fabrication numbers can be achieved, which reduces the part costs. If the mounting brackets are mounted on the top and the bottom, the rigidity of the fishback flanges is increased.  
           [0013]    The mounting brackets are rigid as they have an L-shaped cross section similar to angle iron. Enlarging the connection surface between the fishback flanges and the mounting brackets prevents material fatigue in the connection area. Because the second arm is designed with larger dimensions only in the connection area, sufficient room remains in the remaining area to allow the flow of material to pass.  
           [0014]    The saw tooth design of the upper edge of the fishback flanges ensures a good conveyance effect of the fishback assembly and pulls apart the crop material mat in a second direction resulting in the release of grain and chaff from the crop material mat.  
           [0015]    Since the separation behavior of the fishback assembly depends essentially on the characteristics of the crop material mat fishback flanges having different configurations, such as, rising or falling top edges offer the possibility to adapt the separation behavior to specific crop material mat characteristics.  
           [0016]    A separation device equipped with the fishback assemblys is particularly well suited to use with a straw walker separation device. More specifically, the fishback assembly keeps the crop material mat elevated away from the grid cover covers so that the grid cover apertures do not become clogged. The action of the straw walkers on the fishback assemblies shake the crop material mat in such a manner that grain and chaff fall out of the crop material mat and are further separated by the apertured grid covers.  
           [0017]    In particular, for a subsequent assembly and disassembly, it is very useful if mounting apertures of the fishback assembly correspond to the mounting apertures of the apertured grid covers. Thus, no additional measures are required, such as welding, drilling holes, or similar procedures. Rather, mounting bolts of the corresponding apertured grid covers are loosened, the fishback assembly is placed on top, and both elements are attached with the already existing mounting bolts.  
           [0018]    Because of the high separation capacity required in today&#39;s combines, it is of great advantage in increasing the performance if they are equipped with fishback assemblies on the straw walkers and/or the grain pan and/or the sieves. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]    [0019]FIG. 1 is a semi-schematic side view of a combine.  
         [0020]    [0020]FIG. 2 is a side view of a separation device having a fishback assembly of the present invention.  
         [0021]    [0021]FIG. 3 is a perspective view of the fishback assembly. 
     
    
     DETAILED DESCRIPTION  
       [0022]    A combine  10 , shown in FIG. 1, is supported on wheels  12  and  14 . The front wheels  12  are driven and the back wheels  14  can be steered. The combine  10  is provided with an operator&#39;s cab  16  from which it is operated. Instead of a combine the invention could also be used on a stationary thresher, an experimental threshing installation or similar installations. A grain tank  18  is located behind operator&#39;s cab  16 . Grain temporarily stored in grain tank  18  is discharged therefrom by discharge auger  20 . The grain tank  18  is located on a frame  22 . Crop material entering the combine  10  is threshed by a threshing cylinder  24 , associated concave  26 , and beater  28 . The threshing system divides the crop into larger and smaller components. A significant portion of the smaller components pass through the concave  26  and onto grain pan  32 . The larger components including some smaller components trapped in the mat of threshed crop material is transferred to straw walkers  30 . The straw walkers loosen the threshed crop mat releasing the smaller components. The released smaller components are directed to the grain pan  32 . After the threshed crop mat passes over the straw walkers  30  this material is expelled out the rear of the combine  10 . The smaller components located on the grain pan include grain and chaff. The grain pan  32  directs the smaller components received from the concave  26  and the straw walkers  30  to sieves  34 . Air blown through the sieves  34  by blower  36  blows the chaff out the rear of the combine and allows grain to fall to the floor of the combine where it is collected by a transverse auger which directs the grain to a clean grain elevator. The clean grain elevator lifts the cleaned grain to grain tank  18 . Standing and down crops are collected and gathered by a harvesting assembly, not shown, which directs the harvested crop material to feederhouse  38 . The feederhouse  38  encloses a slat type conveyor that directs the harvested crop material past stone trap  40  to the threshing assembly.  
         [0023]    [0023]FIG. 2 shows the upstream end of the straw walker  30  having lateral walls  42 , a front wall  44 , apertured grid cover  46 , and a first and a second step,  48  and  50 . A third step which is not designated in more detail, is only indicated.  
         [0024]    The straw walker  30  is designed in the form of a trough which in principle opens towards the top, which is enclosed laterally by the side walls  42 , at the front end by the front wall  44  and optionally at the bottom with a floor  52 . In the example shown, the lateral walls  42  is equipped in its upper area with a saw tooth shaped rising and falling edge  54 . The lateral walls  42 , the front wall  44  and the floor  52  are, in the conventional manner, made of steel sheet metal as a single unit, which is either bent out of a metal sheet or assembled by welding. The straw walker  30  is located on crankshafts, not shown, and it is moved by these in an oscillating manner, that is up and down, as well as back and forth.  
         [0025]    The front wall  44  connects the lateral walls  42  and the floor  52  and it forms an assembly which constitutes a rigid connection.  
         [0026]    The apertured grid cover  46  is equipped with a multitude of openings  56 , which are formed by fishplate or punched parts, and which allow the passage of grain and chaff. The apertured grid cover  46  runs parallel to the edge  54  and is screwed onto laterally extending mounting flanges  58 . The mounting flanges are rigidly connected with the lateral walls  42 . A multitude of different grid covers  46  with different openings  56  for different crops maybe provided. In this manner it would be easy to change grid covers for different crops.  
         [0027]    While the separated material is loosened and further separated on the grid covers  46 , the crop material mat, from which the separated material originates, is applied to the saw tooth parts  60  of the edge  54  of lateral walls  42 . Based on the direction of the saw tooth parts  60 , the crop material mat is reliably entrained downstream, that is from left to right in the drawing.  
         [0028]    [0028]FIG. 3 is a fishback assembly  62  according to the invention, comprising four fishback flanges  64  and fore and aft mounting brackets  66 . The fishback assembly  62  is designed as a welded unit and it can be applied to the mounting flanges  58  with or without a grid cover. The area of the separation device  30  starting from and including step  50  is particularly well suited for using the present fishback assembly  62 .  
         [0029]    The fishback flanges  64  are parallel and run longitudinally with respect to the flow of the crop material mat. The fishback flanges  64  are identical, a situation which may be advantageous for reasons pertaining to fabrication technology, but it is not absolutely required. Depending on the width of the straw walker  30  or their apertured grid cover  46 , one or more fishback flanges  64  can be provided. A side view of the fishback flanges  64  shows they have an irregular trapezoidal shape. As the fishback flanges proceed from upstream to downstream as dictated from the flow of crop material they increase in height. The upper edge  68  of the fishback flanges  64  has a saw tooth shape. The position and form of the resulting saw tooth part  70  is selected in such a manner that its rising flank is located upstream, and it is followed by a strongly down sloping, almost vertical flank downstream.  
         [0030]    The mounting brackets  66  are designed as angle profiles and they contain a first leg  72  and a second leg  74 . The first leg  72  is essentially horizontal or in the direction of conveyance, and it contains one or more attachment apertures  76 , which are used for accommodating mounting bolts  82  shown in FIG. 2. In this way the fishback assembly  62  is screwed onto the mounting flanges  58 . However, it is also conceivable to use other attachment assemblies  76 ,  82 , for example, brackets, hooks, spring clips, latches, clasps, and other mechanical couplers.  
         [0031]    The second leg  74  is essentially at a right angle with respect to the first leg  72 . The second leg  74  has tall segments  78  and short segments  80 . The tall segments  78  are where the second leg contacts the fishback flanges, and the small segments  80  are located between the tall segments  78 . For reasons pertaining to fabrication and rigidity, the transition between the segments  78  and  80  forms a regular curve.  
         [0032]    [0032]FIG. 3 shows that the mounting bracket  66  located on the upstream side of the fishback assembly  62 . This upstream mounting bracket  66  is mounted by its first arm  72  to the top of the edge  68  of the fishback flanges  64 . Its second arm  74  extends downward from the first arm  72 . In contrast, the first arm  74  the mounting bracket  66  located on the downstream side of the fishback assembly  62  extends downstream from the fishback flanges  64 . The second arm  74  is connected to the downstream edges of the fishback flanges  64 .  
         [0033]    The connection of the fishback flanges  64  to the mounting brackets  66  advantageously takes place by welding. The fishback flanges  64 , in the assembled state, are parallel, although it seems also possible to use, for example, a diverging arrangement. FIG. 3 shows that the welded construction of the fishback assembly  62  results in a construction which is intrinsically rigid.  
         [0034]    [0034]FIG. 2 shows what position the fishback assembly  62  assumes in the assembled condition, and how it is attached to the straw walker  30 . The fishback assembly  62  covers the same area as the apertured grid cover  46  located on the second step  50 . For the attachment of both, mounting bolts  82  are used, which are inserted through the mounting openings  76  and corresponding mounting openings located in the mounting flanges  58  and in the grid covers  46 . It can clearly be seen that, the edge  68  represents more or less a continuation of the edge  54 , although it is slightly steeper in progression than the edge  54 .  
         [0035]    Finally, it is apparent, that in the area of the fishback assembly  62 , the crop material mat lies only on the top edges  68  of the fishback flanges  64  and that the grain and chaff separated from the crop material mat can fall through the clearance between the fishback flanges  64  onto the apertured grid cover  46 , where it is further separated. Furthermore, it can be seen that the fishback assembly  62  can be assembled and disassembled in the simplest manner, without damaging the straw walker  30 .  
         [0036]    The invention should not be limited by the above described embodiment, but should be limited solely by the claims that follow.