Abstract:
A rotor assembly for extruding randomly shaped food items includes a one-piece finger member. The one-piece finger member reduces the downtime of the extruding machine containing the rotor assembly by reducing the number of parts in the rotor assembly and reducing the adjustment necessary after finger replacement. The proprietary threaded interface between the finger member and the improved extruder machine allows for quick swap out during extruder maintenance.

Description:
BACKGROUND 
     1. Field of the Invention 
     The present invention relates in general to the field of extruders. 
     2. Description of Related Art 
     Machines for extruding, particularly those for extruding randomly shaped cornmeal snacks, include a random extruder assembly for shaping the snacks. For example, one type of randomly shaped cornmeal snacks sold under the trademark CHEETOS® is capable of being extruded from this extruder. CHEETOS® are but one brand of randomly shaped snacks that have been fabricated from extruders like this.  FIG. 1  shows a conventional extruder machine  101  having a hopper assembly  103 , a conveyer assembly  105 , and an extruding assembly  107 . Furthermore, extruding assembly  107  includes a rotor assembly  109 , a stator assemble  111 , and an auger assembly  113 . 
     Referring now also to  FIG. 2  in the drawings, a cross sectional view of conventional extruder machine  101  is illustrated. Material to be extruded, usually cornmeal with selected moisture content, is fed by auger assembly  113  from hopper assembly  103  to the extruder zone  115 . 
     Referring now also to  FIG. 3  in the drawings, a larger cross sectional view of conventional extruder machine  101  is illustrated. Extruding assembly  107  includes rotor assembly  109 , stator assembly  111 , and a servicing distance  117 . Servicing distance  117  is the spacing between the rotor assembly  109  and the stator assembly  111 . Servicing distance  117  is varied by moving the rotor assembly  109  in relation to the stator assembly  111 . Typically while the machine  101  is serviced the servicing distance  117  is no more than a few inches. The servicing distance  117  allows a technician to maintain both the stator assembly  111  and the rotor assembly  109 . Due to the servicing distance  117  having a limited amount of travel all tooling for maintenance to rotor assembly  109  and stator assembly  111  are limited in travel and therefore it is time consuming to remove a significant number of fasteners for maintenance of rotor assembly  109  and stator assembly  111 . 
     Servicing distance  117  is minimized during operation of machine  101  to a very close gap of typically seventy thousands of an inch. Rotor assembly  109  rotates typically at six hundred rotations per minute. Both the rotor assembly  109  and the stator assembly  111  are heated and remain heated during operation of machine  101 . As the cornmeal is expelled from the very close gap between rotor assembly  109  and stator assembly  111  the cornmeal twists and expands before falling on conveyer assembly  105 . 
     Referring now also to  FIG. 4  in the drawings, a perspective view of rotor assembly  109  and to  FIG. 5  in the drawings, an exploded view of rotor assembly  109 , both are illustrated. Rotor assembly  109  includes a rotor coupling  141  secured to a rotor base  145  by rotor base set screws  149 . Located between rotor coupling  141  and rotor base  145  is a dowel pin  143 . A die plate  153  is coupled to rotor base  145  by socket cap screws  157 . Die plate  153  is typically made of bronze. Bronze has been the material of choice for the die plate because of the thermal properties of bronze. Socket cap screws  157  are located on the back side of the die plate  153  to prevent the extruding material from filling the screw head cavity. Die fingers  161  are located in openings in rotor base  145  and die plate  153  and secured by a press fit between die fingers  161  and rotor base  145 . Press fit is a light press between ½ to 1/1000 press. Die fingers  161  are fabricated from rectangular cold rolled  303  stainless steel bars. A cutter holder  165  is clamped to rotor base  145  by tightening clamping bolt  169 . External cutter  174  is coupled to cutter holder  165  by cutter screw  179 . Replacing the external cutters is a time consuming task because of the alignment the external cutters  174  require. Since the cutter holder  165  is clamped to the rotor base  145  considerable time is required to align the external cutters  174 . Another design flaw results in broken cutter holders  165  by over tighten the bolt  169 . A plug  183  is coupled to rotor base  145  by a plug set screw  185  thereby sealing the center of rotor assembly  109 . Rotor coupling set screws  189  are used to couple rotor assembly  109  to machine  101 . 
     Die fingers  161  wear out quickly due to the friction of the corn meal and to acids, starches, and moisture contained in the corn meal. The normal life of the die fingers  161  is 350 to 400 hours of operation. Approximately two hours are required to replace the three die fingers  161 . The considerable down time results from being forced to remove the rotor base  145 . Removal of the rotor base  145  is necessary because the die fingers  161  can only be removed from the rotor base  145  when the rotor base  145  is not installed. Additionally the die plate  153  cannot be replaced without removal of the rotor base  145  because of the location of the socket cap screws  157 . Additional down time occurs because of the time required to realign the rotor assemble  109  after replacing the die fingers  161  and the limited access to the rotor assembly  109  in the servicing distance  117 . Additionally the preferred method to remove the worn die fingers  161  from the rotor base  145  consist of hammering the worn die fingers  161  out of the rotor base  145  to overcome the press fit. If a mechanic slips and strikes the rotor base  145  instead of the die fingers  161  then the rotor base  145  may be damaged by the errant blow. 
     Thus, there exists significant room for improvement in the art for overcoming these and other shortcomings of conventional extruder machine for extruding randomly shaped snacks. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       The novel features believed characteristic of the embodiments of the present application are set forth in the appended claims. However, the embodiments themselves, as well as a preferred mode of use, and further objectives and advantages thereof, will best be understood by reference to the following detailed description when read in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of a conventional extruding machine; 
         FIG. 2  is a cross-sectional view of the conventional extruding machine of  FIG. 1  taken at II-II in  FIG. 1 ; 
         FIG. 3  is a partial enlarged cross-sectional view of the conventional extruding machine of  FIG. 2 ; 
         FIG. 4  is a perspective view of a conventional rotor assembly; 
         FIG. 5  is an exploded perspective view of conventional rotor assembly of  FIG. 4 ; 
         FIG. 6  is a perspective view of an improved extruding machine according to the present application; 
         FIG. 7  is a partial enlarged view of the improved extruding machine of  FIG. 6  according to the present application; 
         FIG. 8  is a cross-sectional view of the improved extruding machine of  FIG. 6  taken at VIII-VIII in  FIG. 6  according to the present application; 
         FIG. 9  is a partial enlarged perspective view of improved extruding assembly according to the present application; 
         FIG. 10  is a perspective view of an improved extruding machine having a twin threaded screw auger according to the present application; 
         FIG. 11  is an exploded perspective view of improved extruding assembly having a twin threaded screw auger according to the present application; 
         FIG. 12  is a partial enlarged exploded perspective view of improved extruding assembly having a twin threaded screw auger from  FIG. 11  according to the present application; 
         FIG. 13  is an exploded perspective view of improved extruding assembly having a twin threaded screw auger according to the present application; 
         FIG. 14  is a partial enlarged exploded perspective view of improved extruding assembly having a twin threaded screw auger from  FIG. 13  according to the present application; 
         FIG. 15  is a perspective view of an improved rotor assembly according to the present application; 
         FIG. 16  is an exploded perspective view of improved rotor assembly of  FIG. 15  according to the present application; 
         FIG. 17  is a perspective view of a finger member according to the present application; 
         FIG. 18  is a perspective view of a finger member according to the present application; and 
         FIG. 19  is a perspective view of a finger member wrench according to the present application. 
     
    
    
     While the assembly of the present application is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular embodiment disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present application as defined by the appended claims. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Illustrative embodiments of the rotor assembly are provided below. It will of course be appreciated that in the development of any actual embodiment, numerous implementation-specific decisions will be made to achieve the developer&#39;s specific goals, such as compliance with assembly-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. 
     Referring to  FIG. 6  in the drawings, a preferred embodiment of an improved extruding machine for extruding randomly shaped cornmeal snacks according to the present application is illustrated. Randomly shaped cornmeal snacks sold under the trademark CHEETOS® are capable of being extruded from this extruder, however, other extruded snacks could be fabricated. CHEETOS® are but one brand of randomly shaped snacks that can be fabricated from extruders according to the present application. Other randomly shaped snacks could be fabricated from a material other than cornmeal, such as potato, seaweed, rice, cassava, parsnip, and carrot. An improved extruder machine  201  having a hopper assembly  203 , a conveyer assembly  205 , and an extruding assembly  207 . Furthermore, extruding assembly  207  includes a rotor assembly  209 , a stator assemble  211 , and an auger assembly  213 . Auger assembly  213  includes an auger motor assembly  223  coupled to a single screw auger assembly  229 . A limitation with single screw auger is their tendency to slip, wear out quickly, and the limited pressure they can apply to the extruder. 
     Referring now also to  FIG. 7  in the drawings, an enlarged perspective view of improved extruding machine  201  is illustrated. Single screw auger assembly  229  is coupled to stator assembly  211  and coupled to an auger interface  230 . As shown in  FIG. 6  and  FIG. 7  single screw auger assembly  229  retracts from auger interface  230  for maintenance. Stator assembly  211  includes a stator die plate  235  and a stator mounting assembly  239 . Rotor assembly  209  includes a rotor head assembly  241  coupled to a drive shaft assembly  243 . Rotor head assembly  241  is capable of rotating about a center axis and is capable of moving axially in relation to stator assembly  211 . 
     Referring now also to  FIG. 8  in the drawings, a cross sectional view of improved extruder machine  201  is illustrated and to  FIG. 9 , an enlarged view of  FIG. 8  is illustrated. Material to be extruded, usually cornmeal with selected moisture content, is fed to an auger assembly  213  by hopper assembly  203 . Auger assembly  213  feeds cornmeal to the extruder assembly  215  through a chute  214 . Extruder assembly  215  includes rotor assembly  209 , stator assembly  211 , and a servicing distance  217 . Servicing distance  217  is the spacing between the rotor assembly  209  and the stator assembly  211 . Servicing distance  217  is varied by moving the rotor assembly  209  in relation to the stator assembly  211 . Typically while the machine  201  is serviced the servicing distance  217  is no more than a few inches. The servicing distance  217  allows a technician to maintain both the stator assembly  211  and the rotor assembly  209 . Due to the servicing distance  217  having a limited amount of travel all tooling for maintenance to rotor assembly  209  and stator assembly  211  are limited in travel and therefore it is time consuming to remove a significant number of fasteners for maintenance of rotor assembly  209  and stator assembly  211 . 
     Referring now also to  FIG. 10  the drawings, an alternative embodiment of extruder machine  301  according to the present application is illustrated. Extruder machine  301  includes an extruder assembly  315 , a hopper assembly  303 , a drive assembly  304 , and a servicing assembly  306 . 
     Referring now also to  FIGS. 11 ,  12 ,  13 , and  14  in the drawings, an alternative embodiment of extruder assembly  315  according to the present application is illustrated. Extruder assembly  315  includes a rotor assembly  309 , a stator assembly  311 , and an auger assembly  313 . Auger assembly  313  includes an auger motor assembly  323  coupled to a multi screw assembly  329 . Multi screw assembly  329  is coupled to stator assembly  311 . In the preferred embodiment multi twin screw assembly  329  includes a first auger screw  330  and a second auger screw  331  that are parallel to each other and rotate in the same direction. In an alternative embodiment the multi auger screws are parallel and rotate in opposite directions. In an alternative embodiment there would be additional augers screws, such as a third auger screw and so forth as long as space in auger assembly would allow. Multiple auger screws reduce the slippage and wear associated with single screw augers and allow a greater variety of ingredients to be extruded. Stator assembly  311  includes a stator die plate  335  and a stator mounting assembly  339 . Stator die plate  335  is fabricated from stainless steel. Rotor assembly  309  includes a rotor head assembly  341  coupled to a drive shaft assembly  343 . Drive shaft assembly  343  is coupled to drive assembly  304 . Rotor head assembly  341  is capable of rotating about a center axis by drive assembly  304  and is capable of moving axially in relation to stator assembly  311  by means of servicing assembly  306 . 
     Referring now also to  FIG. 15  in the drawings, a perspective view of a preferred embodiment of a rotor assembly  409  is illustrated and to  FIG. 16  in the drawings, an exploded view of rotor assembly  409  is illustrated. Rotor assembly  409  includes a one-piece finger member  413 , a die plate  417 , cutting assemblies  421 , and a rotor base  425 . Rotor base  425  has a first end  427  and a second end  429 . First end  427  of rotor base  425  is secured to extruding machine by tightening set screws  426 . Second end  429  of rotor base  425  includes a rotor base flange  428 . In the center of rotor base flange  428  is a finger member receptacle  430  configured for releasable attachment of finger member  413 . Finger member receptacle  430  has multi-indexed non-continuous threaded surfaces  431 . In other embodiments the number of indexed threaded surfaces could be greater or less than three. In the preferred embodiment the finger member receptacle  430  includes three indexed threaded surfaces  431  with higher pitch threads. Alternatively or in combination with the high pitch of the threading, the pitch of the lead angle is different than the pitch of the threading. The threading is proprietary and serves to reduce imitators duplicating unauthorized replacement parts and aids in the quick removal of parts from the assembly. In alternate embodiments the entire receptacle is threaded. Located on the circumference of rotor base flange are cutting assembly slots  433 . 
     Cutting assemblies  421  include an external cutter  435  and a cutting screw  437 . External cutter  435  includes a holder portion  439  and a blade portion  441 . A cutter interface  443  is the region where the holder portion  439  and the blade portion  441  intersect. In this embodiment cutter interface  443  is filleted, however, it should be apparent that cutter interface  443  might be curved and non-filleted. External cutters  435  are coupled to rotor base  425  and are secured by cutting screws  437 . External cutters  435  are prevented from rotating relative to rotor base  425  by being located in the cutting assembly slots  433  located on the rotor base flange  428 . Additionally, cutting assembly slots  433  ensure blade portion  441  is precisely located axially. 
     Die plate  417  has a first end  459  and a second end  457  located at the opposite end. Die plate  417  includes a centered aperture  445  to allow the finger member  413  to mount to the rotor base  425  through die plate  417 . Die plate  417  is coupled to rotor base  425  by socket cap screws  455 . Socket cap screws  455  mount through the rotor base flange  428  and into the second end  459  of the die plate  417 . It is important that first end  457  of die plate  417  does not contain fasteners. First end  457  of the die plate  417  is in constant contact with the ground cornmeal therefore any fasteners that were exposed in first end  457  would be clogged with the ground corn meal. This clogging would inhibit the maintenance of the extruding machine  301 . In the preferred embodiment die plate  417  is fabricated from stainless steel, preferably a  304  stainless steel. In an alternative embodiment die plate  417   b  is fabricated from bronze. Die plates  417  fabricated from stainless steel require additional surface preparation including bead blasting and coated carbide cutters to machine the part. The additional surface preparation is needed in order for the die plates  417  fabricated from stainless steel to mimic the frictional twisting generated by die plates  417   b  fabricated from bronze. Die plates  417  fabricated from stainless steel are lasting three times longer or more than dies plates  417   b  fabricated from bronze. 
     Referring now also to  FIG. 17  and  FIG. 18  in the drawings, perspective views of a finger member  413  are illustrated. Finger member  413  has a first end  461  and a second end  463 . In the preferred embodiment the diameter of the second end  463  is uniform. In alternate embodiments the diameter of the second end could have a taper and or a rubber gasket to minimize the migration of cornmeal. Preferably first end  461  has multi-indexed non-continuous threaded flanges  465 ; however the threading could be continuous. The threading is proprietary and serves to reduce imitator duplicating unauthorized replacement parts and aids in the quick removal of parts from the assembly. In the preferred embodiment the pitch of the threading is higher than normal threading and very course. The courser the threading the easier to remove the finger member  413 . The higher pitch allows the finger member  413  to engage with less rotational distance compared to a finger member threaded with lower pitch threads. Alternatively or in combination with the high pitch of the threading, the pitch of the lead angle is different than the pitch of the threading. A benefit of the custom threading is reduced unauthorized production of knock-off parts. Second end  463  has fingers  467  and a cone  469 . At the top of the cone  469  is a flattened area  471 . Finger member  413  is preferable machined from a round bar of  303  stainless steel. Finger assemblies fabricated from round bars of  303  stainless steel have more durability than previous fingers made from flat bars of  303  stainless steel due to a different stainless steel manufacturing process or perhaps the arrangement of the grains in the round bar compared to the flat bar. In other embodiments finger member  413  may be fabricated from other metals as long as it was economically feasible to fabricate them and the finger member  413  proved durable. 
     Flattened area  471  is critical in adjusting the augers position when there is a single auger screw. The auger is properly engaged with rotor assembly  409  by adjusting auger until contact is made between auger and flattened area  471 . The auger is then backed away from the flattened area a short amount. In the preferred embodiment finger member  413  has three fingers  467 , however, in other embodiments the number of fingers is greater than three and in other embodiments the number of fingers may be less than three but no less than one finger. The orientation and the position of the fingers  467  relative to the finger member  413  may be adjusted. Mounting of finger member  413  to rotor base  425  in the preferred embodiment is by a quick releasing threaded coupling  473 . In the preferred embodiment the finger member  413  can be released from the rotor base by rotating finger member approximately only 60 degrees relative to rotor base  425 . This greatly speeds up the removal and replacement of finger member  413 . 
     Referring now also to  FIG. 19  in the drawings, a perspective view of a finger member wrench  475  is illustrated. Removal of finger member  413  from rotor base  425  is assisted by utilizing finger member wrench  475  with cutouts  477 . Cutouts  477  are shaped like fingers  467  with extra material removed to protect edges of fingers  467 . Finger member wrench  475  has a groove  479  cut into it and a hole  481  located between cutouts  477 . Finger member wrench  475  could also used for installing finger member  413  into rotor base  425 . 
     It is apparent that an assembly with significant advantages has been described and illustrated. The particular embodiments disclosed above are illustrative only, as the embodiments may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. It is therefore evident that the particular embodiments disclosed above may be altered or modified, and all such variations are considered within the scope and spirit of the application. Accordingly, the protection sought herein is as set forth in the description. Although the present embodiments are shown above, they are not limited to just these embodiments, but are amenable to various changes and modifications without departing from the spirit thereof.