Abstract:
Methods and equipment suitable for slicing products into lattice-type slices or chips. The methods and equipment utilize a knife assembly that includes a corrugated knife having oppositely-disposed surfaces that terminate at a cutting edge. The knife assembly further includes a knife holder having a registration surface and an oppositely-disposed knife seat configured to mated with a first surface of the corrugated knife, and means for securing the knife to the knife seat of the knife holder. The knife seat comprises a pattern of peaks and valleys complementary to a pattern of peaks and valleys in the first surface of the corrugated knife. The securing means cooperates with the knife holder to inhibit accumulation of solids of products along at least one of the first and second surfaces of the corrugated knife, and/or stabilizes the knife by reducing a cantilevered beam length thereof.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/222,932, filed Sep. 24, 2015, the contents of which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention generally relates to methods and machines for cutting products, including but not limited to food products. The invention particularly relates to machines equipped with a cutting head and an impeller assembly adapted to rotate within the cutting head, wherein the impeller assembly transports products to knives situated in the cutting head for slicing the products into slices or chips of the lattice type. 
         [0003]    Various types of equipment are known for slicing, shredding and granulating food products, as nonlimiting examples, vegetables, fruits, dairy products, and meat products. Widely used machines for this purpose are commercially available from Urschel Laboratories, Inc., and include machines under the names Model CC® and Model CCL. The Model CC® and CCL machines are centrifugal-type slicers capable of slicing a wide variety of products at high production capacities. Whereas the Model CC® line of machines is particularly adapted to produce uniform slices, strip cuts, shreds and granulations, the Model CCL line is particularly adapted to produce slices or chips of a waffle or lattice type (hereinafter, collectively referred to as a lattice), nonlimiting examples of which are represented in  FIG. 1 . 
         [0004]    From top to bottom, the images in  FIG. 1  represent fine, coarse, and deep lattice cuts, which may be used to produce, as nonlimiting examples, lattice potato chips and potato waffle fries. As evident from  FIG. 1 , the opposing surfaces of the slices are characterized by a periodic pattern having a corrugated or sinusoidal shape with rounded peaks and valleys when viewed edgewise, though sharper peaks and valleys are also possible. The lattice cut is produced by sequentially crosscutting a product at two different angles, typically ninety degrees apart, using one or more knives each having a cutting edge formed to have the desired periodic pattern of the slices to be produced. Such a knife is referred to herein as a corrugated knife, which is intended to denote the presence of a cutting edge on the knife that is characterized by peaks and valleys when the knife is viewed edgewise, but is not restricted to cutting edges having peaks and valleys with any particular shape or pattern, periodic or otherwise. 
         [0005]    Original versions of the Model CCL are represented in U.S. Pat. Nos. 3,139,127 and 3,139,130, whose contents are incorporated herein by reference. A representation of a Model CCL machine  10  is shown in  FIG. 2 , and drawings of a Model CCL machine  10  adapted from U.S. Pat. Nos. 3,139,127 and 3,139,130 are included herein as  FIGS. 3 through 5 . The machines  10  depicted in  FIGS. 2-5  include a frame  12  that supports a power unit  14 , a stationary cutter assembly (cutting head)  16 , and a carriage or conveyor (impeller) assembly  18  that is rotatably disposed within the cutting head  16  for feeding products to the cutting head  16 . The cutting head  16  and impeller assembly  18  are coaxial, and the cutting head  16  remains stationary while the impeller assembly  18  rotates within the cutting head  16  about their common axis. The cutting head  16  and impeller assembly  18  are enclosed in a housing  20 , and products are delivered to the cutting head  16  and impeller assembly  18  through a feed hopper  22 .  FIG. 4  represents a perspective view of the machine  10  of  FIG. 3 , with the hopper  22  retracted and the housing  20  and cutting head  16  removed to expose the impeller assembly  18 , which is represented as having four tubular guides  24  that deliver products to the cutting head  16 .  FIG. 5  is an isolated top fragmentary view of the cutting head  16  and impeller assembly  18 , and shows corrugated cutting knives  26  mounted at the perimeter of the cutting head  16 , each secured to a segment  28  of the cutting head  16  between a knife holder  30  and clamp  32 . The assemblage of a knife  26 , knife holder  30 , and clamp  32  forms what will be referred to herein as a knife assembly  34 . From  FIG. 3 , it is evident that the interior of the cutting head  16  has a spheroidal surface. Consequently, the knives  26 , knife holders  30 , and clamps  32  also have spheroidal shapes. 
         [0006]    The hopper  22  delivers products to the impeller assembly  18 , and centrifugal forces cause products to move outward into engagement with the interior spheroidal surface of the cutting head  16 , including the interior surfaces of the knife holders  30 . The interior surfaces of the knife holders  30  are referred to herein as registration surfaces of the knife holders  30 . While engaged with the registration surfaces, in regular succession the products encounter and are sliced by the knives  26  circumferentially spaced within the cutting head  16 . 
         [0007]      FIG. 6  represents a fragmentary perspective view of a cutting head  16  and impeller assembly  18  corresponding to the machine  10  shown in  FIG. 5 .  FIG. 6  is useful for further describing operating principles of the Model CCL. Product delivered to the feed hopper (not shown) enters the impeller assembly  18  at {circle around ( 1 )}. The impeller assembly  18 , including its four rotating tubular guides  24 , rotates about the vertical axis shared with the cutting head  16 . Centrifugal forces urge products  35  within the tubular guides  24  radially outward through the tubular guides  24  toward the radially outward extremities {circle around ( 2 )} thereof. The tubular guides  24  are driven to rotate about their respective axes so that the product  35  within each guide  24  is rotated about its horizontal axis while the impeller assembly  18  rotates about its vertical axis. As centrifugal forces hold the products  35  tightly against the spheroidal interior surface of the cutting head  16 , the tubular guides  24  cause the products  35  to make an approximate one-quarter turn between each of four knife stations {circle around ( 3 )}, resulting in the desired lattice cut being generated in slices  36  as the knives  26  are encountered. 
         [0008]      FIG. 7  is an isolated perspective view of a cutting head  16  of a CCL machine  10  corresponding to the machine  10  shown in  FIGS. 5 and 6 . The cutting head  16  is again shown as comprising segments  28  that define the spheroidal interior surface of the cutting head  16 , and corrugated cutting knives  26  secured to each segment  28  between a knife holder  30  and clamp  32 .  FIG. 8  evidences the curvature of a knife  26 , knife holder  30 , and clamp  32 . As evident from  FIGS. 7 and 8 , the knife holder  30  defines a knife seat  44  that has a smooth cylindrical surface on which a knife  26  of essentially any shape can be placed. Likewise, the knife clamp  32  has a simple arc on its leading (clamping) edge to clamp the knife  26  against the knife holder  30 . The clamp  32  visible in  FIG. 7  can be seen to have a tapered outer surface  32   a  at its leading edge (generally conical as a result of the arcuate shape of the clamp  32 ) to gently direct slices up and over the clamp  32  as they leave the cutting head  16 . As evident from  FIG. 8 , the peaks and valleys of the knife  26  and simple arcuate shapes of the knife holder  30  and clamp  32  result in the presence of gaps or openings  38  between the knife  26  and both the knife holder  30  and clamp  32 . 
         [0009]    Further descriptions pertaining to the construction and operation of Model CCL machines are contained in U.S. Pat. Nos. 3,139,127 and 3,139,130. 
         [0010]    CCL machines of the types described above have performed exceedingly well. Even so, as is apparent from  FIG. 8 , as products and slices pass over the knife holder  30  and clamp  32 , a portion of the product and slice may scrape the leading edges of the holder  30  and clamp  32 . Over time, the openings  38  between the shaped knife  26 , knife holder  30  and clamp  32  may accumulate solids, for example, starch if the product being sliced is a vegetable or fruit. Though such accumulation does not pose an issue with well-maintained machines, if unattended the accumulated solids may eventually lever the knife  26  off the knife seat  44  of the knife holder  30 , resulting in the production of thinner slices. If, as a result, the knife  26  is no longer rigidly registered against the knife seat  44  of the knife holder  30 , the leading (sharp) edge of the knife  26  can become destabilized, diminishing slice accuracy and quality. Another issue that may be encountered is that, due to the dual rotary nature of the slicing action on a CCL machine, i.e., products rotating about the horizontal axis of the tubular guides  24  while also rotating about the vertical axis of the impeller assembly  18 , the knives  26  may experience a force that is transverse to the slicing force that occurs in a roughly horizontal direction. Over time, this transverse force may result in vertical movement of the knives  26  (i.e., parallel with the axis of rotation of the impeller assembly  18 ), indicated by the arrow  40  in  FIG. 8 . These circumstances may become exacerbated by increasing the amplitude of the peaks and valleys of the knives  26 , for example, the coarse and deep lattice cuts in comparison to the fine lattice cut depicted in  FIG. 1 . 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0011]    The present invention provides methods and equipment suitable for slicing products into slices or chips of the lattice type. 
         [0012]    According to one aspect of the invention, a knife assembly of a slicing machine adapted to slice products includes a corrugated knife having oppositely-disposed surfaces that terminate at a cutting edge. The cutting edge and at least portions of the first and second surfaces adjacent thereto are characterized by a pattern of peaks and valleys. The knife assembly further includes a knife holder having a registration surface and an oppositely-disposed knife seat configured to mated with a first surface of the corrugated knife, and means for securing the corrugated knife to the knife seat of the knife holder. The knife seat comprises a pattern of peaks and valleys complementary to the pattern of peaks and valleys in the first surface of the corrugated knife. The securing means contacts the second surface of the corrugated knife and cooperates with the knife holder to inhibit accumulation of solids of products along at least one of the first and second surfaces of the corrugated knife, and/or stabilizes the corrugated knife by reducing a cantilevered beam length thereof. 
         [0013]    The securing means may comprise a member having fingers and notches therebetween that define a pattern complementary to the pattern of peaks and valleys in the second surface of the corrugated knife, with the fingers thereof engaging the valleys on the second surface of the corrugated knife. In some nonlimiting embodiments, the member may be a clamp that directly secures the knife to the knife holder, and in further nonlimiting embodiments the member may be an adapter that, along with the knife, is secured by a clamp to the knife holder. 
         [0014]    Other aspects of the invention include machines and methods for cutting products using knife assemblies of the type described above to produce slice products. Such a machine or method delivers products to a perimeter of a cutting head through action of rotating an impeller assembly and a delivering means associated therewith, and slicing the products with a corrugated knife to produce slices or chips of a lattice type. 
         [0015]    Technical effects of knife assemblies, methods and machines described above preferably include the ability of the securing means to reduce or eliminate openings resulting from the peaks and valleys of a corrugated knife. In so doing, the securing means is able to reduce the accumulation of solids that might eventually lever the knife off the knife seat of its holder and result in the production of thinner slices and/or lead to knife instability. Consequently, the securing means is capable of addressing various potential quality issues, including slice accuracy and variation, and therefore reduce scrap, improve yields, etc. 
         [0016]    Other aspects and advantages of this invention will be better appreciated from the following detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  schematically represents lattice-type slices that may be produced with machines and components of the types represented in  FIGS. 2 through 8 . 
           [0018]      FIG. 2  is a side view representing a Model CCL machine known in the art. 
           [0019]      FIG. 3  is a side view in partial cross-section of a Model CCL machine. 
           [0020]      FIG. 4  is a perspective view of the machine of  FIG. 3 , with a housing and cutting head removed to expose an impeller assembly. 
           [0021]      FIG. 5  is a top fragmentary view of the cutting head and impeller assembly of the machine of  FIG. 3 . 
           [0022]      FIG. 6  is a perspective view of a cutting head and impeller assembly of a Model CCL machine. 
           [0023]      FIG. 7  is a perspective view representing the cutting head of  FIG. 6 . 
           [0024]      FIG. 8  is an edge view of a knife assembly of the cutting head of  FIG. 7 , and depicts the relative cross-sectional shapes of a knife holder, a knife clamp, and a knife secured therebetween. 
           [0025]      FIGS. 9A and 9B  are perspective views of two versions of knife holders suitable for use with the machines and components thereof represented in  FIGS. 2 through 7 , wherein the knife holder of  FIG. 9A  has a knife seat having a periodic pattern complementary to a corrugated knife, and the knife holder of  FIG. 9B  has a knife seat having a periodic pattern complementary to a corrugated knife mated therewith, and an oppositely-disposed registration surface having a periodic pattern similar to that of the corrugated knife. 
           [0026]      FIG. 10  represents a knife clamp suitable for use with the knife holders of  FIGS. 9A and 9B . 
           [0027]      FIG. 11  is an image showing a knife assembly comprising the knife and knife holder of  FIG. 9B , an adapter, and a knife clamp that clamps the knife and adapter to the knife holder. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0028]      FIGS. 9A, 9B, 10, and 11  represent knife assemblies and components thereof suitable for use with machines having certain features similar to the machines  10  represented in  FIGS. 2 through 7 , and in some instances may be a modification or retrofit of such a machine  10 . In particular, nonlimiting embodiments of the invention will be illustrated and described hereinafter in reference to a machine having components arranged as described for the machine  10  in  FIGS. 2 through 7 , though it will be appreciated that the teachings of the invention are more generally applicable to a variety of machines. Furthermore, though the knife assemblies and components represented in  FIGS. 9A, 9B, 10, and 11  will be discussed in reference to slicing food products, it should be understood that the knife assemblies, as well as cutting heads, impeller assemblies, and machines to which they may be assembled, can be utilized to cut other types of products. 
         [0029]    The knife assemblies and knife assembly components represented in  FIGS. 9A, 9B, 10, and 11  are configured to reduce or eliminate potential issues previously discussed in reference to  FIG. 8  as arising from the presence of openings  38  between the corrugated knife  26  and the simple arcuate shapes of the knife holder  30  and/or clamp  32  visible in  FIG. 8 . In so doing, the knife assemblies and knife assembly components are further capable of addressing certain undesirable consequences of the openings  38 , for example, the incidence of scraping between product, product slices, and the leading edges of the holder  30  and clamp  32 , the accumulation of solids within the openings  38 , the levering of the knife  26  off the knife seat of the knife holder  30  that leads to the production of thinner slices, destabilization of the leading (cutting) edge of the knife  26 , and vertical movement of the knife  26  (arrow  40  in  FIG. 8 ), i.e., parallel with the axis of rotation of the impeller assembly  18 . 
         [0030]      FIGS. 9A and 9B  are perspective views of two versions of knife holders  130 A and  130 B. Each knife holder  130 A and  130 B is configured for assembly with a corrugated cutting knife, for example, the corrugated knife  126  shown mated with the knife holder  130 B of  FIG. 9B , so that a leading portion of the knife  126  that defines a cutting edge  127  projects beyond a leading edge  146 A or  146 B of the holder  130 A and  130 B, for example, as depicted in  FIG. 9B . As previously noted, the knife  126  is considered to be “corrugated” as a result of its cutting edge  127 , as well as at least adjacent portions of oppositely-disposed surfaces  129  and  131  of the knife  126  that terminate at the cutting edge  127 , being characterized by peaks and valleys when the knife  126  is viewed edgewise. As also previously noted, knives within the scope of the invention are not restricted to any particular shape or pattern of peaks and valleys. Each knife holder  130 A and  130 B is configured for assembly with a clamp, as nonlimiting examples, either of two clamps  132 A and  132 B shown in  FIGS. 10 and 11 , for the purpose of clamping the corrugated knife  126  to the holder  130 A and  130 B. A knife assembly (as a nonlimiting example, the knife assembly  134  shown in  FIG. 11 ) is formed by clamping a knife to either knife holder  130 A and  130 B with either clamp  132 A and  132 B. 
         [0031]    The knife holder  130 A of  FIG. 9A  has a registration surface  142 A formed to have a simple arcuate shape similar to that of the knife holder  30  seen in  FIGS. 5, 7, and 8 . The knife holder  130 A further has a knife seat  144 A that is opposite its registration surface  142 A and formed to have a pattern of peaks and valleys complementary to peaks and valleys of a corrugated knife to be mated thereto, for example, the knife  126  shown mated with the knife holder  130 B of  FIG. 9B . Similarly, the knife holder  130 B of  FIG. 9B  defines a knife seat  144 B formed to have a pattern of peaks and valleys complementary to the peaks and valleys in the surface  129  of the corrugated knife  126  with which it is mated. The knife seats  144 A and  144 B are preferably configured to substantially or entirely fill the openings or gaps between the knife  126  and the knife holders  130 A and  130 B that would otherwise result from the valleys in the surface  129  of the knife  126  secured to the knife holder  130 A or  130 B. 
         [0032]    The knife holder  130 A of  FIG. 9A  has a blunt leading edge  146 A as a result of the different surface contours of its registration surface  142 A and knife seat  144 A. In contrast, the registration surface  142 B of the knife holder  130 B of  FIG. 9B  does not have a simple arcuate shape, but instead is shaped to define a pattern complementary to that of the corrugated knife  126 . The shapes of the registration surface  142 B and knife seat  144 B of the knife holder  130 B are in phase, such that the leading edge  146 B is sharp and substantially of constant thickness, in contrast to the periodically varying thickness that can be seen on the leading edge  146 A of the knife holder  130 A of  FIG. 9A . In the nonlimiting examples of  FIGS. 9A and 9B , the patterns of peaks and valleys on the knife  126 , registration surface  142 B, and knife seats  144 A and  144 B are periodic, e.g., substantially sinusoidal, although irregular patterns are also within the scope of the invention. 
         [0033]    In investigations leading to the present invention, the periodic pattern of peaks and valleys on the knife seat  144 A of the knife holder  130 A of  FIG. 9A  provided immediate improvements in both knife position retention and solids accumulation relative to the knife holder  30  depicted in  FIGS. 5, 7 and 8 . The knife holder  130 B shown in  FIG. 9B , further modified to have the periodic pattern seen on its registration surface  142 B, was concluded to further reduce solids accumulation by reducing scraping of products that might otherwise occur as a result of the blunt leading edge  146 A of the knife holder  130 A of  FIG. 9A  formed by the simple arcuate shape of its registration surface  142 A. 
         [0034]      FIG. 10  represents a knife clamp  132 A adapted to be assembled with either of the knife holders  130 A and  130 B of  FIGS. 9A and 9B  to clamp a corrugated knife thereto, for example, the knife  126  mated with the knife seat  144 B of the knife holder  130 B in  FIG. 9B . The knife clamp  132 A shown in  FIG. 10  is fabricated to have “fingers”  148  that are preferably, though not necessarily, capable of multiple purposes. For example, the fingers  148  may be used to at least partially close openings or gaps between the clamp  132 A and a corrugated knife (e.g.,  126 ) that are present as a result of valleys in the surface  131  of the knife  126 , thereby reducing solids accumulation in the gaps. For this purpose, the fingers  148  sufficiently protrude into the valleys in the surface  131  facing the clamp  132 A to close the openings to the gaps that exist between the knife  126  and clamp  132 A. Alternatively or in addition, the fingers  148  may improve the stability of the leading edge of the knife  126  by reducing the cantilevered beam length of the knife  126 , which as used herein refers to the length or distance between the cutting edge  127  of the knife  126  and the nearest adjacent extremity of the clamp  132 A applying a clamping load to the knife  126 . In this case, the nearest adjacent extremity of the clamp  132 A is defined by the distal ends of the fingers  148 , which physically engage the surface  131  of the knife  126  within the valleys facing the clamp  132 A. The fingers  148  and resulting notches or recesses  150  therebetween define a pattern (e.g., a periodic pattern) complementary to the pattern of the knife  126  secured with the clamp  132 A to the knife holder  130 A or  130 B. 
         [0035]    As an alternative to the knife clamp  132 A of  FIG. 10 ,  FIG. 11  shows the knife assembly  134  as comprising a corrugated knife  126 , the knife holder  130 B of  FIG. 9B , a knife clamp  132 B similar to the clamp  32  represented in  FIGS. 5, 7 and 8 , and an adapter  152  clamped to the knife holder  130 B between the clamp  132 B and knife  126 . Similar to the clamp  32  described in reference to  FIGS. 6 and 7 , the clamp  132 B depicted in  FIG. 11  has a tapered outer leading surface  156  at its leading edge (generally conical as a result of the arcuate shape of the clamp  132 B). Similar to the clamp  132 A seen in  FIG. 10 , the adapter  152  is fabricated to have fingers  158  that, in combination with notches or recesses  160  therebetween, define a periodic pattern complementary to the periodic pattern in the surface  131  of the corrugated knife  126  mated with the adapter  152 . The adapter  152  of  FIG. 11  preferably mates tightly with the surface  131  of the knife  126  so that its fingers  158  at least partially close gaps between the leading edge  162  of the clamp  132 B and the valleys on the surface  131  of the knife  126  defined by the corrugated shape of the knife  126 . In combination, the knife holder  130 B and adapter  152  cooperate to prevent or at least reduce the accumulation of solids within the valleys present in the surface  131  of the knife  126  beneath the clamp  132 B. As such, the adapter  152  serves to eliminate the need to fabricate the clamp  132 B to have fingers. The adapter  152  preferably defines a conical outer leading surface that effectively serves as an extension of the conical outer leading surface  156  of the clamp  132 B so that, as discussed in relation to the clamp  32  of  FIGS. 5, 7 and 8 , slices are gently directed up and over the clamp  132 B to reduce or eliminate scraping of the slices. 
         [0036]    Consistent with  FIGS. 9A and 9B , the knife seat  144 B (not visible) of the knife holder  130 B is preferably formed to have a periodic pattern that is complementary with the surface  129  of the corrugated knife  126  to substantially or entirely eliminate openings or gaps therebetween that would otherwise result from the valleys on the knife surface  129 . 
         [0037]    The adapter  152  depicted in  FIG. 11  can be fabricated using rapid manufacturing and rapid prototyping technologies, for example, stereolithographically fabricated by 3-D printing stereolithography (SLA) resins directly from a CAD model of the adapter  152 . Because SLA resins are typically brittle, non-food grade, and hygroscopic, another alternative is to cast the adapter  152  from a food-grade material, for example, urethane. The adapter  152  can also be fabricated from other materials, for example, stainless steel, and fabricated using more traditional manufacturing methods. The use of a hardened stainless steel can result in a stronger adapter  152  that is better able to assist the clamp  132 B in stabilizing the knife  126  by helping to generate a greater clamping force. The use of various other materials and nontraditional manufacturing methods are also foreseeable in the fabrication of the adapter  152  disclosed herein. 
         [0038]    It is also within the scope of the invention that a knife holder  130 B of the type shown in  FIG. 9B  could be sufficiently sharpened to serve as a corrugated knife  126 , eliminating the need for a separate knife  126 , clamp  132 B, and adapter  152  and thereby inherently avoiding the tendency for solids to accumulate within the valleys present in the surfaces  129  and  131  of the knife  126  as a result of its corrugated shape. 
         [0039]    While the invention has been described in terms of specific embodiments, it is apparent that other forms could be adopted by one skilled in the art. For example, the knives  126 , knife holders  130 A and  130 B, clamps  132 A and  132 B, and adapter  152  could differ in appearance and construction from the embodiments shown in the drawings and used with machines, impeller assemblies, and cutting heads that differ in appearance and construction from what is shown in the drawings, certain functions of their components could be performed by components of different construction but capable of a similar (though not necessarily equivalent) function, and various materials and processes could be used to fabricate the knife assemblies and their components. In addition, the invention encompasses additional embodiments in which one or more features or aspects of different disclosed embodiments may be combined. Though the nonlimiting embodiments of the cutting heads shown in the drawings are particularly adapted to cut food products into slices, it is foreseeable that the impeller assemblies could be used in combination with cutting heads adapted for slicing other materials. Therefore, the scope of the invention is to be limited only by the following claims.