Abstract:
Orifice plates, grinding machines, and method of using the same are provided that can process a material. In one aspect, an orifice plate includes multiple orifices, at least one of which has two tapered segments aligned with and operably connected to each other and that taper downwardly from respective outer portions to inner portions. An intermediate bore may connect to minimum diameter portions of each of the tapering segments so that the tapering segments are connected to each other by way of the intermediate bore.

Description:
FIELD OF THE INVENTION 
     The present disclosure relates to grinding machines and, more particularly, to orifice plates used in grinding assemblies of grinding machines for grinding meat and other materials. 
     BACKGROUND 
     Grinding machines are known in the food processing industries. It is widely known that some grinding machines can convert cuts of meat, trimmings, and/or other meat stock into ground meat products. This can be done by way of rotating knives that scrape across a front surface of an orifice plate while the cuts of meat and/or trimmings are pushed through orifices that extend longitudinally through the thickness of the orifice plate, such as by operation of an auger. Some orifice plates include conically tapered orifices in which entry openings of the orifices at the front surface of the orifice plate are larger than exit openings of the orifices at an opposing back surface of the orifice plate. 
     SUMMARY 
     In accordance with one aspect, a grinding machine is provided for processing materials, such as a food product, and includes a grinder assembly and an orifice plate that is operably mounted to the grinder assembly. The orifice plate has orifices, each of which has two tapering segments, which may be defined by a restriction segment and an expansion segment, that taper from locations that are near first and second end surfaces of the orifice plate downwardly and inwardly toward an intermediate portion of the orifice plate. This dual tapering of the orifices may provide an orifice plate that is symmetrical about a transversely cross-sectional plane so that the orifice has the same dimensional characteristics in a traverse direction through the orifice plate from either the first or second end surface and out of the other one of the first and second end surface. This may allow the orifice plate to be mounted with either the first or second end surface facing an upstream direction with respect to a travel path of material through the grinder assembly so that the orifice plate can be flipped over if the upstream facing one of the first and second end surfaces becomes worn due to the flow of material and/or engagement of blades of a knife assembly that may scrape against such surface, which may double the use-life of the orifice plate and reduce inventory requirements for replacement orifice plates. This may also provide orifices that have defined restriction and expansion segments, regardless of which one of the first and second end surfaces faces the upstream direction with respect to the travel path of the material through the grinder assembly. The restriction and expansion segments of each orifice may provide radial compression followed by controlled and restricted radial expansion of the material which may provide improved textural characteristics of a meat material when compared to forcing the material through either openings having constant diameters or openings having continuously reducing diameters along their entire lengths. The radial compression in the restriction segment followed by controlled and restricted radial expansion of the material in the expansion segment of the orifice plate may also prevent shattering of frozen material that is being ground with the grinding machine. 
     In accordance with another aspect, a method of using a grinding machine for processing a material, such as a food product, is provided. The method includes mounting an orifice plate that has multiple orifices extending there through in a grinder assembly in a first position in which a first end surface of the orifice plate faces an upstream direction with respect to a travel path along which the material is conveyed through the grinder assembly. A second end surface of the orifice plate faces downstream with respect to the travel path of the material. Material is forced through multiple orifices of the orifice plate while the orifice plate is in the first position. The orifice plate is then mounted in a second position in the grinder assembly in which the second end surface of the orifice plate faces the upstream direction with respect to the travel path of the material and the first end surface of the orifice plate faces the downstream direction with respect to the travel path of the material. Material is forced through the multiple orifices of the orifice plate while the orifice plate is in the second position. 
     In accordance with a further aspect, a grinding machine for processing a material, such as a food product, is provided and includes a grinder assembly that can receive a material to be processed and can convey the material along a travel path that extends generally longitudinally with respect to the grinder assembly. An orifice plate is arranged with respect to the grinder assembly so that the material is forced through the orifice plate while being conveyed through the grinder assembly. The orifice plate includes a first end surface that faces upstream with respect to the travel path of the material and a second end surface that faces downstream with respect to the travel path of the material. Multiple orifices extend through the orifice plate, generally transversely between the first and second end surfaces. Each of the multiple orifices includes a first opening defined at the first end surface and having a first width and a second opening defined at the second end surface and having a second width. An intermediate bore is arranged between the first and second openings and define a third width that is smaller than each of the first and second widths. A restriction segment may be defined between the first opening and the intermediate bore and an expansion segment may be defined between the intermediate bore and the second opening. 
     According to still another aspect, (i) the first opening and restriction segment, and (ii) the second opening and the expansion segment are mirror images of each other about a cross-sectional plane extending transversely through a center of the orifice plate. 
     According to still a further aspect, the first and second openings may have circular perimeter shapes and a common diameter. The intermediate bore may have a circular perimeter shape and may be aligned coaxially with respect to the first and second openings. 
     According to yet another aspect, each orifice may include a first outer bore that extends from the first opening in the first end surface, toward the central bore, and a second outer bore that extends from the second opening in the second end surface, toward the central bore. The first and second outer bores may have the same diameter as the first and second openings. The first and second outer bores may each define a length thereof and each of the diameters of the first and second outer bores are constant along the respective lengths. 
     According to yet a further aspect, the restriction segment includes a tapering bore that extends between the first outer bore and the intermediate bore. The tapering bore of the restriction segment may connect respective ends of the first outer bore and the intermediate bore to each other. The tapering bore of the restriction segment may conically taper downwardly from a connection location with the first outer bore to a connection location with the intermediate bore. The expansion segment may include a tapering bore that extends between the second outer bore and the intermediate bore. The tapering bore of the expansion segment may connect respective ends of the second outer bore and the intermediate bore to each other. The tapering bore of the expansion segment may conically taper downwardly from a connection location with the second outer bore to a connection location with the intermediate bore. In this way, (i) the first opening and restriction segment, and (ii) the second opening and the expansion segment may be mirror images of each other about a cross-sectional plane that extends transversely through a center of the orifice plate. This may allow the orifice plate to be flipped over so that at each orifice, what was initially an expansion segment can serve as a subsequent restriction segment and what was initially a restriction segment can serve as a subsequent expansion segment so as to provide improved textural characteristics of a food product that may result from radial compression followed by controlled and restricted radial expansion of the food product while traveling through the orifice plate, regardless of which end surface of the orifice plate faces upstream versus downstream. 
     In another aspect, a grinding machine for processing material is provided. The grinding machine includes a grinder assembly adapted to receive a material to be processed and convey the material along a travel path extending generally longitudinally with respect to the grinder assembly, and an orifice plate arranged with respect to the grinder assembly to have the material forced through the orifice plate while the material is conveyed through the grinder assembly. The orifice plate includes a first end surface facing upstream with respect to the travel path of the material, a second end surface facing downstream with respect to the travel path of the material, and a plurality of orifices defined through the orifice plate from the first end surface to the second end surface. At least one of the plurality of orifices includes a first opening defined at the first end surface and having a first width, a second opening defined at the second end surface and having a second width, an intermediate portion between the first and second openings and having a third width that is smaller than the first width and the second width, a restriction segment defined between the first opening and the intermediate portion, and an expansion segment defined between the intermediate portion and the second opening. 
     In a further aspect, a grinding machine for processing a material is provided and includes a grinder assembly adapted to receive a material to be processed and convey the material along a travel path extending generally longitudinally with respect to the grinder assembly, and an orifice plate arranged with respect to the grinder assembly to have the material forced through the orifice plate while the material is conveyed through the grinder assembly. The orifice plate includes opposing first and second end surfaces and multiple orifices defined through the orifice plate from the first end surface to the second end surface. At least one of the multiple orifices includes a restriction segment including a length and a width with the width of the restriction segment decreasing moving along the length in a first direction from the first end surface toward the second end surface, and an expansion segment operably connected with the restriction segment and including a length and a width with the width of the expansion segment decreasing moving along the length in a second direction from the second end surface toward the first end surface. 
     In still another aspect, an orifice plate for a grinding machine is provided and includes a first end surface, a second end surface opposite the first end surface, and a plurality of orifices defined in the orifice plate from the first end surface to the second end surface. At least one of the plurality of orifices includes a first tapered section decreasing in width as it extends in a first direction from the first end surface toward the second end surface and a second tapered section decreasing in width as it extends in a second direction from the second end surface toward the first end surface. 
     A method of using a grinding machine for processing a material is provided. The method includes mounting an orifice plate that has multiple orifices extending there through in a grinder assembly in a first position, in which a first end surface of the orifice plate faces an upstream direction with respect to a travel path along which the material is conveyed through the grinder assembly and a second end surface of the orifice plate faces a downstream direction with respect to the travel path of the material. At least one of the orifices of the orifice plate tapers inwardly from both the first and second end surfaces. The method also includes forcing the material through the multiple orifices of the orifice plate while the orifice plate is in the first position, mounting the orifice plate in the grinder assembly in a second position, in which the second end surface of the orifice plate faces the upstream direction and the first end surface of the orifice plate faces the downstream direction, and forcing the material through the multiple orifices of the orifice plate while the orifice plate is in the second position. 
     Various other features, objects, and advantages of the invention will be made apparent from the following description taken together with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views, together with the detailed description below, are incorporated in and form part of the specification, and serve to further illustrate embodiments of concepts that include the claimed invention, and explain various principles and advantages of those embodiments. 
         FIG. 1  is a top isometric view of an exemplary grinding machine incorporating various aspects of the present invention. 
         FIG. 2  is an exploded view of a grinder assembly of the grinding machine shown in  FIG. 1 , the grinding assembly includes an exemplary orifice plate. 
         FIG. 3  is a front elevational view of the orifice plate shown in  FIG. 2 . 
         FIG. 4  is a cross-sectional view of the orifice plate taken along line  4 - 4  in  FIG. 3 . 
         FIG. 5  is an enlarged detail of a portion of  FIG. 4  taken at dashed circle  5  in  FIG. 4 . 
     
    
    
     Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present disclosure. 
     DETAILED DESCRIPTION 
       FIG. 1  illustrates an exemplary grinding machine  5  used for processing materials such as, for example, food and other products. The grinding machine  5  is described as being used for converting meat, trimmings, and/or other meat stock (hereinafter “meat”), by way of grinding, into a ground meat product(s), while noting that grinding machine  5  in other embodiments may be implemented for grinding-type processing of other materials, which may be food materials and other products. A suitable grinding machine  5  and its components are disclosed in the commonly owned U.S. Pat. No. 7,905,436, the entire disclosure of which is incorporated herein by reference. The grinding machine  5  includes a base  7  that houses various mechanical components (including electric motors, drive components, and controls), as is known for suitably operating the grinding machine  5 . The grinding machine  5  has a hopper assembly  10  into which the meat is introduced into the grinding machine  5  and a grinder assembly  12  that processes the meat into a ground meat product(s). Grinder assembly  12  includes a grinder head  14  in which an orifice plate  60  is incorporated, as explained in greater detail elsewhere herein. 
     Referring now to  FIG. 2 , the grinder head  14  includes a generally tubular body  16 , with a flange  18  at one end of the body  16  that connects to the hopper assembly  10 . An opposing end of the tubular body  16  includes an outlet  20  that expands conically from the remainder of the tubular body  16  and has an externally threaded collar  22  and lugs  23  that extend radially inward toward a center of an opening defined at the outlet  20 . At least a portion of an inner surface of the grinder head tubular body  16  includes flutes  24  that extend inwardly, radially toward a central longitudinal axis  150  of the grinder head  14  and are aligned angularly with respect to the central longitudinal axis  150  so as to define a spiraling arrangement. The particular dimensions of the flutes  24  may vary along their lengths and are selected to produce desired flow characteristics of meat through the grinder head  14 , for example, to control a rate of material backflow between adjacent flutes  24 . 
     With further reference to  FIG. 2 , feed screw  26  is concentrically and rotationally mounted in the grinder head tubular body  16  and is arranged so that rotation of the feed screw  26  advances the meat from the hopper assembly  10  through the grinder head  14 . In this way, a central longitudinal axis  150  of the feed screw  26  corresponds to a travel path that extends generally longitudinally through the grinder head  14  and thus grinder assembly  12 , along which the meat is conveyed. When assembled, a single central longitudinal axis  150  extends through a longitudinal center of the components of the grinder assembly  12 . Feed screw  26  has a circumferential sidewall  28  and flutes  30  that extend outwardly, radially from the circumferential sidewall  28  and are aligned angularly with respect to a central longitudinal axis  150  of the feed screw  26  so as to define a spiraling arrangement. Like the inwardly extending flutes  24  of the grinder head tubular body  16 , the outwardly extending flutes  30  of the feed screw  26  can have dimensions that vary along their lengths and that are selected to produce desired flow characteristics of meat through the grinder head  14 . An outlet end  32  of the feed screw  26  that is concentrically housed in the outlet  20  of the grinder head tubular body  16  includes a centrally located bore  34  that extends longitudinally into the feed screw  26 . A shoulder  36  is defined at a bottom surface of a counter bore that extends into the outlet end  32  of the feed screw  26 . 
     With continued reference to  FIG. 2 , a center pin  38  includes a first end  40  that is housed in the bore  34  at the feed screw outlet end  32  and a second end  42  that extends outwardly beyond the feed screw outlet end  32 . A bore  44  extends into the second end  42  of the center pin  38 . A spacer washer and spring pack assembly  46  is concentrically arranged on the center pin  38 , near the second end  42 . In the complete assemblage, the second end  42  extends beyond the spacer washer and spring pack assembly  46 , a first side of the spacer washer and spring pack assembly  46  abuts the shoulder  36  of the feed screw outlet end  32 , and a second side of the spacer washer and spring pack assembly  46  face an opposite direction, away from the shoulder  36 . A bushing  48  with longitudinally extending spaced apart lugs  49  at its exterior surface is concentrically arranged upon the second end  42  of the center pin  38 . A knife assembly  50  has a central hub  52  and radially extending arms  54  to which blades  56  are mounted. The central hub  52  is arranged concentrically on the second end  42  of the center pin  38  so that the spacer washer and spring pack assembly  46  engages and biases the central hub  52 , and thus the entire knife assembly  50 , away from the feed screw shoulder  36 . 
     An auger  58  has a post  59  at an inwardly facing end that inserts into the bore  44  of the second end  42  of the center pin  38 . The feed screw  26 , knife assembly  50 , and auger  58  are keyed or otherwise locked in rotational unison with each other. Orifice plate  60 , explained in greater detail elsewhere herein, is arranged with respect to the grinder head  14  so that the meat is forced through the orifice plate  60  while being conveyed through the grinder head  14  by operation of feed screw  26 . Orifice plate  60  has an inner surface  62  ( FIG. 3 ) including spaced apart depressions  64  that accept the lugs  49  of the bushing  48  and defines an outer periphery of a central opening  65  in which the bushing  48  is arranged. Orifice plate  60  includes an outer surface  66  that has notches  68  that engage the lugs  23  of the grinder head outlet  20 . This engagement prevents rotation of the orifice plate  60  relative to the grinder head  14 . Thus, the orifice plate  60  is maintained in a fixed position with respect to the grinder head  14  while the blades  56  of the knife assembly  50  are pushed against, as biased by the spacer washer and spring pack assembly  46 , and rotationally scrape across, the orifice plate  60 . As shown in  FIG. 2 , orifice plate  60  may include collection passages  70  that allow hard materials such as bone gristle, which are unable to be cut by the blades  56 , to pass there through. 
     Still referring to  FIG. 2 , collection cone  72  is arranged concentrically outside of the auger  58  and abuts the orifice plate  60  so that hard materials that pass through the collection passages  70  of the orifice plate  60  are directed into the collection cone  72 . Rotation of the auger  58  within the collection cone  72  advances the hard materials through the collection cone  72  and a collection discharge tube  74  ( FIG. 1 ) that is operably connected to the collection cone  72 . A bridge  76  that has radially extending plate guards  78  which prevent access into the grinder head  14  concentrically supports the collection cone  72 . The bridge  76  includes a rim  80  that engages an outer portion of the orifice plate  60 . A mounting ring  82  with internal threads  84  holds the bridge  76  against the orifice plate  60  by way of the mounting ring internal threads  84  engaging the threaded collar  22  of the grinder head tubular body  16  so as to secure the mounting ring  82  to the grinder head  14 . 
     Referring now to  FIG. 3 , the orifice plate  60  has a generally circular outer perimeter shape that is defined by the outer surface  66  with the notches  68  extending inwardly, on opposing sides of the orifice plate  60 . The orifice plate  60  has a generally circular inner perimeter shape that is defined by the inner surface  62  from which depressions  64  extend. A pair of mounting apertures  86  extends through outer portions and on opposing sides of the orifice plate  60 . The mounting apertures  86  receive pins that extend from the bridge rim  80  to maintain registration of the orifice plate  60  and the bridge  76 . As shown in  FIG. 4 , the orifice plate  60  has a first end surface  90  and an opposing second end surface  92 , between which a thickness of the orifice plate  60  is defined. 
     Referring now to  FIGS. 3 and 4 , the orifice plate  60  defines multiple orifices  94  there through from the first end surface  90  to the second end surface  92 . The orifices  94  are spaced apart from each other extend through the entire orifice plate  60  so as to provide a perforated configuration of the orifice plate  60  through which the meat can be forced during use of the grinding machine  5  ( FIG. 1 ). 
     Referring now to  FIGS. 4 and 5 , each orifice  94  of this embodiment is substantially symmetrical about a midpoint  152  along its length when viewed from transverse cross-section such as those of  FIGS. 4 and 5 . Each orifice  94  includes a first opening  96  at the first end surface  90  and a second opening  98  at the second end surface  92 . A first outer bore  100  is arranged radially inward of a first outer bore side wall  101  ( FIG. 5 ) that extends from the first opening  96  into the first end surface  90  toward the second end surface  92 . A second outer bore  102  is arranged radially inward of a second outer bore side wall  103  ( FIG. 5 ) that extends from the second opening  98  into the second end surface  92  toward the first end surface  90 . The first and second outer bores  100 ,  102  have the same opening widths as the first and second openings  96 ,  98 , respectively, and define substantially constant opening widths or diameters along their lengths. 
     With further reference to  FIGS. 4 and 5 , each orifice  94  defines a restriction segment  104  which is defined by a tapering bore  106  ( FIG. 5 ) that is arranged radially inward of a first tapering side wall  108  that connects to the inward most portion of the first outer bore side wall  101 . An expansion segment  110  is defined by a tapering bore  112  that is arranged radially inward of a second tapering side wall  114  ( FIG. 5 ) that connects to the inward most portion of the second outer bore side wall  103 . The first and second tapering side walls  108 ,  114  may extend at a variety of different angels with respect to a central longitudinal axis  154  of the orifice  94  and be within the spirit and scope of the present invention. In some exemplary embodiments, the first and second tapering side walls  108 ,  114  may extend at angles of between about 10 degrees and about 20 degrees. In other exemplary embodiments, the walls  108 ,  114  may extend at an angle of about 15 degrees. 
     With continued reference to  FIGS. 4 and 5 , an intermediate bore  116  extends between and connects the restriction and expansion segments  104 ,  110  to each other. The intermediate bore  116  is arranged radially inward of an intermediate side wall  118  that extends between and connects the inward most portions of the first and second tapering side walls  108 ,  114 . Like the first and second outer bores  100 ,  102 , the intermediate bore  116  has a substantially constant opening width diameter along its length. However, the intermediate bore  116  has a smaller diameter than the diameters of the first and second outer bores  100 ,  102 . In some exemplary embodiments, the intermediate bore  116  may have a diameter that is about three-quarters of the diameter of first and second outer bores  100 ,  102 . In one exemplary embodiment, the first and second outer bores  100 ,  102  may have diameters of about one inch and the intermediate bore  116  may have a diameter of about three-quarters of an inch. 
     In light of the above, the orifice plate  60  is directionally indifferent, whereby the orifice plate  60  can be mounted in the grinder assembly with either the first or second end surface  90 ,  92  facing toward the knife assembly ( FIG. 2 ). That is because the orifice plate  60  is symmetrical about a cross-sectional plane that extends transversely through a midpoint of the intermediate bore  116 , so that (i) the first opening  96 , first outer bore  100 , and restriction segment  104  and (ii) the second opening  98 , second outer bore  102 , and expansion segment  110 , respectively, are mirror images of each other. 
     Accordingly, the orifice plate  60  can be mounted in the grinder assembly  12  in a first position in which the first end surface  90  faces an upstream direction so that the first end surface  90  is engaged by the knife assembly  50  ( FIG. 2 ) and the second end surface  92  faces a downstream direction. The grinding machine  5  ( FIG. 1 ) can be operated with the orifice plate  60  in the first position until the first end surface  90  endures sufficient wear to justify changing. This may occur when, for example, the sharp corner edges defined at the first openings  96  of the orifices  94  dull due to the engagements with the knife assembly  50  and/or the meat being forced through the orifice plate  60 , or when the first end surface  90  wears sufficiently so that it is no longer flat enough to provide a shearing interface against which the knife assembly  50  can scrape. At this point, instead of replacing the orifice plate  60  with a new orifice plate  60 , the orifice plate  60  is flipped over. Referring to  FIG. 2 , this is done by partially disassembling the grinder assembly  12  by removing the mounting ring  82 , bridge  76 , and collection cone  72 . The orifice plate  60  is axially withdrawn from the grinder assembly  12  so that the notches  68  are free of their engagement with the posts  23  of the grinder head  14 . The orifice plate  60  is then flipped over so that the second end surface  92  faces toward the knife assembly  50 . The notches  68  of the orifice plate  60  are aligned with and slid into engagement upon the lugs  23  of the grinder head  14 . The collection cone  72 , bridge  76 , and mounting ring  82  are reinstalled into the grinder assembly  12 . Upon reassembly of these components, the orifice plate  60  is in a second position. The grinding machine  5  ( FIG. 1 ) is operated again with the orifice plate  60  in the second position. While in the second position of the orifice plate  60 , the orifices  94  impart the same compression and restriction along with allowing for the same post-compression expansion as they did when the orifice plate  60  was in the first position. 
     It is understood that the drawings and the above relate to a certain embodiment of the present invention, but that the invention is not limited to the specific configuration shown and described. For example, while the orifices are shown as having outer bores and then tapered sections that lead to intermediate bore, it is contemplated that the tapered sections of the bores may be formed to extend all the way to the outer surfaces of the orifice plate. It is also contemplated that the intermediate bore may be eliminated and that the tapered sections of the bore may directly intersect each other at or near the center of the orifice plate. It is further contemplated that the intermediate bore may have a longer length than that shown and described. In addition, it is contemplated that the bores need not necessarily be symmetrical about a central plane of the orifice plate. For example, the orifices on one side of the orifice plate may have a greater or lesser angle of taper then on the other, so that a selected side of the orifice plate can be used, for example, according to certain characteristics of the material being ground. It is also understood that, while the drawings and description relate to all orifices having a tapered configuration, only certain of the orifices may be tapered and others may be straight-sided. 
     The Abstract is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter. 
     While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that other embodiments and implementations are possible within the scope of the invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents.