Patent Publication Number: US-10786922-B2

Title: Modular units, clamping assemblies, and slicing machines equipped therewith

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/506,667, filed May 16, 2017, the contents of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention generally relates to machines for cutting products, including but not limited to slicing food products. The invention particularly relates to modular units with clamping assemblies for securing knives to slicing machines, and to slicing machines equipped therewith. 
     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. The Model CC® line of machines is particularly adapted to produce uniform slices, strip cuts, shreds and granulations, and the Model CCL line is particularly adapted to produce slices or chips of a waffle or lattice type. Certain configurations and aspects of Model CC® machines are represented in U.S. Pat. Nos. 3,139,128, 3,139,129, 5,694,824 and 6,968,765, the entire contents of which are incorporated herein by reference. Certain configurations and aspects of Model CCL machines are represented in U.S. Pat. Nos. 3,139,127 and 3,139,130, the entire contents of which are incorporated herein by reference. 
       FIG. 1  schematically depicts a machine  10  representative of a Model CC® machine. The machine  10  includes a generally annular-shaped cutting head  12  equipped with cutting knives (not shown) mounted at its inner circumference. An impeller  14  is coaxially mounted within the cutting head  12  and has an axis  17  of rotation that coincides with an axis of the cutting head  12 . The impeller  14  is rotationally driven about its axis  17  through a shaft that is enclosed within a housing  18  and coupled to a gear box  16 . The cutting head  12  is mounted on a support ring  15  above the gear box  16  and remains stationary as the impeller  14  rotates. Products are delivered to the cutting head  12  and impeller  14  through a feed hopper  11  located above the impeller  14 . In operation, as the hopper  11  delivers products to the impeller  14 , centrifugal forces cause the products to move outward into engagement with the knives of the cutting head  12 . The impeller  14  comprises generally radially-oriented paddles  13 , each having a face that engages and directs the products radially outward toward and against the knives of the cutting head  12  as the impeller  14  rotates. Other aspects pertaining to the construction and operation of Model CC® machines, including improved embodiments thereof, can be appreciated from U.S. Pat. Nos. 3,139,128, 3,139,129, 5,694,824, 6,968,765, 7,658,133, 8,161,856, 9,193,086, 9,469,041, and 9,517,572 and U.S. Patent Application Publication Nos. 2016/0158953 and 2016/0361831. 
       FIG. 2  is an isolated view of the cutting head  12  of  FIG. 1 , and  FIG. 3  is a fragmentary bottom view of the cutting head  12 . The cutting head  12  is generally annular-shaped with cutting knives  20  mounted on its perimeter. Each knife  20  projects radially inward in a direction generally opposite the direction of rotation of the impeller  14 , and defines a cutting edge at its radially innermost extremity. The cutting head  12  shown in  FIG. 2  further comprises a lower support ring  22 , an upper support ring  24 , and circumferentially-spaced support segments, referred to herein as shoes  26 . The knives  20  of the cutting head  12  are individually secured with clamping assemblies  28  to the shoes  26 . Each clamping assembly  28  includes a knife holder  28 A mounted with fasteners  29  to the radially inward-facing side of a shoe  26 , and a clamp  28 B mounted on the radially outward-facing side of a shoe  26  to secure a knife  20  to the knife holder  28 A. The shoes  26  are represented as secured with fasteners  30  to the support rings  22  and  24 . The shoes  26  are equipped with coaxial pivot pins (not shown) that engage holes in the support rings  22  and  24 . By pivoting on its pins, the orientation of a shoe  26  can be adjusted to alter the radial location of the cutting edge of its knife  20  with respect to the axis of the cutting head  12 , thereby controlling the thickness of the sliced food product. As an example, adjustment can be achieved with an adjusting screw and/or pin  32  located circumferentially behind the pivot pins.  FIG. 2  further shows optional gate insert strips  34  mounted with fasteners  35  to each shoe  26 , which the food product crosses prior to encountering the knife  20  mounted to the succeeding shoe  26 . 
       FIGS. 2 and 3  show the knives  20  and clamps  28 B secured to their respective knife holders  28 A with fasteners  36 . Alignment of the knife  20  and clamp  28 B of each assembly  28  is achieved with pins  38  that protrude from the support surface of the knife holder  26 B. As better understood through the detail view of  FIG. 4 , the opposing surfaces of the knife holder  28 A and clamp  28 B result in the clamp  28 B applying a force to the knife  20  adjacent its cutting edge.  FIG. 5  shows an isolated exploded view of a shoe  26  and clamping assembly  28  of the cutting head  12  of  FIGS. 2 and 3 . 
       FIGS. 6 and 7  depict a quick-clamping assembly  40  that can be used in lieu of the fasteners  36  shown in  FIGS. 2 and 3 . The clamping assembly  40  comprises a knife holder  40 A and clamp  40 B, the latter of which may be similar if not identical to the clamp  28 B of  FIGS. 2 and 3 . The knife holder  40 A includes an insert  42  that supports the knife  20  near its cutting edge and serves to protect the edge of the knife holder  40 A from stones or other debris that are often accompany food products that undergo slicing. The knife holder  40 A and clamp  40 B are loosely assembled together with a fastener  44  that is installed in the knife holder  40 A, passes through the clamp  40 B, and is threaded into a clamping bar  46 . An eccentric clamping rod  48  is disposed within a recess  50  formed in a surface of the knife holder  40 A, and has a flat  52  defined on its otherwise cylindrical peripheral surface. The clamping rod  48  is situated between and contacts the knife holder  40 A and a proximal end of the clamp  40 B opposite the knife  20 . The rod  48  can be rotated between clamping and release positions, which serve to secure and release, respectively, the knife  20 . The clamping position is depicted in  FIG. 6  and results from the proximal end of the clamp  40 B being engaged by the cylindrical surface of the rod  48 , which forces the proximal end outward away from the knife holder  40 A and, with the clamping bar  46  serving as a fulcrum, forces the oppositely-disposed end of the clamp  40 B into engagement with the knife  20 . The force applied to the clamp  40 B by the rod  48  can be released by rotating the rod  48  so that its flat  52  faces the proximal end of the clamp  40 B. 
     While the Model CC® has performed extremely well for its intended purpose, further improvements are continuously desired and sought for slicing machines of the type represented by the Model CC®. 
     BRIEF DESCRIPTION OF THE INVENTION 
     The present invention provides modular units with clamping assemblies for securing knives to slicing machines, and a slicing machine having a cutting head equipped with one or more modular units mounted thereto for securing knives to the cutting head. 
     According to one aspect of the invention, a modular unit is provided that comprises mounting blocks that are spaced apart in an axial direction, and a clamping assembly assembled with the mounting blocks so as to be between the mounting blocks. According to a preferred aspect of the invention, the clamping assembly includes a knife holder, a knife supported by the knife holder, a clamp overlying the knife holder so that the knife is between the knife holder and the clamp, and a cam rod that secures the clamp to the knife holder and clamps the knife therebetween. The cam rod has oppositely-disposed ends rotatably coupled with the mounting blocks and a camming portion between the oppositely-disposed ends and arranged for contacting the clamp. The cam rod is rotatable to have a clamping position and a release position, the camming portion applies a force that clamps the clamp against the knife holder when the cam rod is in the clamping position, and the camming portion releases the force against the clamp when the cam rod is in the release position. The clamping assembly further includes means for inhibiting deflection of the camming portion away from the knife holder when the cam rod is in the clamping position. 
     According to another preferred aspect of the invention, a slicing machine is provided that includes a cutting head to which a modular unit of the type described above can be mounted. The cutting head of such a machine may optionally comprise a first stop that prevents rotation of the cam rod beyond the clamping position and a second stop that prevents rotation of the cam rod beyond the release position. 
     Other aspects of the invention include methods by which a slicing machine of the type described above can be modified. 
     Technical aspects of modular units described above preferably include the ability to minimize the extent to which the camming portion of the cam rod can deflect when engaged with and applying a clamping force to the clamp, and the ability to promote a more uniform clamping force applied by the clamp along the length of the knife. 
     Other aspects and advantages of this invention will be better appreciated from the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  schematically represents a side view in partial cross-section of a slicing machine known in the art. 
         FIG. 2  is a perspective view representing a cutting head of a type suitable for use with the slicing machine of  FIG. 1 . 
         FIG. 3  is a bottom view showing a fragment of the cutting head of  FIG. 2 , and  FIG. 4  is a detailed view of a portion of a clamping assembly of the cutting head. 
         FIG. 5  is an isolated exploded view of a shoe and a clamping assembly of the cutting head of  FIGS. 2 and 3 . 
         FIGS. 6 and 7  are side and cross-sectional views, respectively, of an alternative clamping assembly capable of use with the cutting head of  FIG. 2 . 
         FIG. 8  is a perspective view representing a cutting head in accordance with a nonlimiting embodiment of the invention and configured for use with the slicing machine of  FIG. 1 . 
         FIG. 9  is a perspective view of an individual modular unit assembled to support rings of the cutting head of  FIG. 8 . 
         FIG. 10  contains isolated perspective and exploded views of the modular unit of  FIG. 9 . 
         FIG. 11  is a cross-sectional view of a modular unit of the type represented in  FIGS. 8 through 10 . 
         FIG. 12  is a cross-sectional view of the modular unit of  FIG. 11  showing the unit in a closed position by which a flat knife is secured to the unit, and  FIG. 13  is an end view of a portion of a cutting head representing the position of a lever relative to a support ring to which the modular unit of  FIG. 12  is mounted. 
         FIG. 14  is a cross-sectional view of the modular unit of  FIGS. 11 and 12  showing the unit in an open position by which the flat knife is released from the unit, and  FIG. 15  is an end view of a portion of a cutting head representing the position of the lever relative to the support ring. 
         FIG. 16  is a perspective view of a shaped knife. 
         FIG. 17  is a cross-sectional view of the modular unit of  FIGS. 11, 12 and 14  showing the unit in an open position by which a shaped knife is released from the unit, and  FIG. 18  is an end view of a portion of a cutting head representing the position of the lever relative to a support ring modified for use with the shaped knife of  FIG. 16 . 
         FIG. 19  is a perspective view corresponding to the portion of the cutting head of  FIGS. 14 and 15  and showing stops for the lever that operates the modular unit in combination with the flat knife as depicted in  FIGS. 12 through 15 . 
         FIG. 20  is a perspective view corresponding to the portion of the cutting head of  FIGS. 17 and 18  and showing stops for the lever that operates the modular unit in combination with the shaped knife as depicted in  FIGS. 17 and 18 . 
         FIGS. 21, 22 and 23  are perspective views evidencing the modularity of the modular unit of  FIGS. 8 through 20 . 
         FIGS. 24 and 25  are end views of cutting heads showing the modular unit of  FIGS. 8 through 23  installed on support rings of different size (diameters). 
         FIGS. 26 through 33  contain various views representing a modular unit comprising a locking feature in accordance with another nonlimiting embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 8  represents a cutting head  62  that is capable of use with a variety of cutting machines, including the slicing machine  10  depicted in  FIG. 1 , and in some instances may be a modification or retrofit for such a machine.  FIGS. 9 through 33  contain various views of nonlimiting embodiments that utilize one or more modular units  76  to secure knives  70  to the cutting head  62 . The cutting head  62  will be described hereinafter in reference to the slicing machine  10  of  FIG. 1  equipped with an impeller  14  as described in reference to  FIG. 1 , and as such the following discussion will focus primarily on certain aspects of the invention, whereas other aspects not discussed in any detail may be, in terms of structure, function, materials, etc., essentially as was described in reference to  FIGS. 1 through 7 . However, it will be appreciated that the teachings of the invention are more generally applicable to other types of cutting machines. 
     To facilitate the description provided below of the embodiments represented in the drawings, relative terms, including but not limited to, “vertical,” “horizontal,” “lateral,” “front,” “rear,” “side,” “forward,” “rearward,” “upper,” “lower,” “above,” “below,” “right,” “left,” etc., may be used in reference to the orientation of the cutting head  62  as it would be mounted in the machine  10  of  FIG. 1 . On the basis of a coaxial arrangement of the cutting head  62  and the impeller  14  of the machine  10 , relative terms including but not limited to “axial,” “circumferential,” “radial,” etc., and related forms thereof may also be used below to describe the nonlimiting embodiments represented in the drawings. All such relative terms are intended to indicate the construction and relative orientations of components and features of the cutting head  62 , and therefore are relative terms that are useful to describe the illustrated embodiments but should not be otherwise interpreted as limiting the scope of the invention. 
     In the isolated view of  FIG. 8 , the cutting head  62  can be seen to be generally annular-shaped with cutting knives  70  mounted at its perimeter. Each knife  70  projects radially inward in a direction generally opposite the direction of rotation of the impeller  14  within the cutting head  62 , and defines a cutting edge at its radially innermost extremity. The cutting head  62  shown in  FIG. 8  further comprises lower and upper support rings  72  and ring  74  to and between which the circumferentially-spaced modular units  76  are mounted. Each modular unit  76  comprises a clamping assembly  78  that secures an individual knife  70  to the modular unit  76 . As more readily evident in  FIGS. 9, 10, and 11 , the clamping assembly  78  of each modular unit  76  includes a knife holder  80  mounted with fasteners  82  to and between a pair of mounting blocks  84 , which in turn are configured to be secured to the support rings  72  and  74  with fasteners  86 . Due to the positions of the rings  72  and  74  in the cutting head  62 , the mounting blocks  84  are spaced apart in an axial direction of the cutting head  62 . The fasteners  86  preferably rigidly secure the mounting blocks  84  to the rings  72  and  74 . The clamping assembly  78  further includes a clamp  81  mounted between the mounting blocks  84  so that the clamp  81  is positioned on the radially outward-facing side of the holder  80  to secure the knife  70  thereto. The clamp  81  is preferably pivotably mounted to the mounting blocks  84 , and in the embodiment shown the fasteners  86  that secure the mounting blocks  84  to the rings  72  and  74  extend through the blocks  84  to also serve as pivot pins for the clamp  81 . 
     The mounting blocks  84  are equipped with pins  88  that engage holes in the support rings  72  and  74 . By appropriately locating the holes in the rings  72  and  74 , the orientation of the mounting blocks  84 , and consequently the knife  70 , knife holder  80 , and clamp  81  mounted thereto, can be used to alter the radial location of the cutting edge of the knife  70  with respect to the axis of the cutting head  62 , thereby providing relatively coarse control of the thickness of the sliced food product.  FIGS. 8 through 11  further show each modular unit  76  as comprising an adjustable gate  90  secured to the mounting blocks  84  with fasteners  92 . A food product crosses the gate  90  prior to encountering the knife  70  mounted to the succeeding modular unit  76 . To provide relatively fine control of the thickness of the sliced food product, the mounting blocks  84  are equipped with adjustment screws  94  that engage the gates  90  to alter the radial location of a trailing edge  96  ( FIGS. 10 and 11 ) of the gate  90  relative to the cutting edge of the succeeding knife  70 . 
     As more readily apparent from  FIGS. 10 and 11 , the knife  70  is supported by a radially outer surface of the knife holder  80 , and the clamp  81  overlies the holder  80  so that the knife  70  is between the surface of the holder  80  and a radially inward surface of the clamp  81  that faces the holder  80 . Alignment of the knife  70 , holder  80 , and clamp  81  may be achieved with pins  98  that protrude from the knife holder  80  into complementary slots and holes in, respectively, the knife  70  and clamp  81 . As evident from  FIG. 11 , by forcing the clamp  81  toward the holder  80 , an extension  81 A of the clamp  81  will apply a clamping force to the knife  70  adjacent its cutting edge. According to a preferred aspect of the invention, an eccentric cam rod  100  is used as a quick-clamping feature to apply the clamping force to the clamp  81 . The cam rod  100  passes through holes  102  in the mounting blocks  84  and through complementary holes  104  on upstanding flanges  81 B ( FIG. 11 ) located at opposite ends of the clamp  81  to loosely assemble the clamp  81  to the mounting blocks  84  in combination with the pivot axis of the clamp  81  created by the fasteners  86 . 
     As more readily seen in  FIG. 10 , the cam rod  100  comprises a camming portion  106  that engages and disengages the clamp  81  when the rod  100  is rotated between clamping and release positions, which serve to secure and release, respectively, the knife  70 . The release position is depicted in  FIG. 11  and results from the camming portion  106  being disengaged from the clamp  81 , whereas clockwise rotation of the rod  100  (as viewed in  FIG. 11 ) causes its camming portion  106  to eccentrically move into engagement with the surface of the clamp  81 , forcing the clamp  81  into engagement with the knife  70 . The force applied to the clamp  81  by the camming portion  106  can be released by rotating the cam rod  100  counterclockwise. 
     In the illustrated embodiment, the cam rod  100  is rotatably mounted to the mounting blocks  84  of the modular unit  76  as a result of its oppositely-disposed ends  105  being rotatably received in the holes  102  formed in the blocks  84 , enabling the rod  100  to rotate within the holes  102  between the aforementioned clamping and release positions. The ends  105  of the cam rod  100  are preferably coaxial, whereas the camming portion  106  between the ends  105  is eccentric to the ends  105  as well as the holes  102  in which the ends  105  are received, in other words, the axis of the camming portion  106  is parallel but not coaxial with the ends  105  of the cam rod  100 . A handle  108  is provided at one end of the rod  100  to facilitate its rotation by hand. In the illustrated embodiment, the handle  108  is attached to the rod  100  so as to be disposed above the support ring  74  as seen in  FIGS. 8 and 9 . 
     The operation of the modular unit  76  will now be discussed in reference to  FIGS. 12 through 15 , which represent the knife  70  as having a straight cutting edge for producing flat slices. Knives having straight cutting edges will be referred to herein as “flat” knives. As will be subsequently discussed in reference to  FIGS. 16 through 18 , knives of other shapes can be used to produce sliced, strip-cut, shredded and granulated products. 
     In  FIG. 12 , which shows the cam rod  100  in its clamping position, the camming portion  106  is represented as having a cylindrical shape that defines an arcuate camming surface, which contacts the outer surface of the clamp  81  and forces the clamp  81  toward the knife holder  80 . In the clamping position, the camming portion  106  is at its closest proximity to the knife holder  80  due to the eccentricity of the camming portion  106 , with the result that the camming portion  106  applies an increasingly greater force to the clamp  81  as the camming portion  106  is rotated in the clamping direction (clockwise in  FIGS. 12 through 15 ). As a result, the knife  70  is clamped between the knife holder  80  and clamp  81 .  FIG. 13  represents the clamping position of the cam rod  100  as being established by a stop  112  defined by the support ring  74 . The stop  112  limits the clockwise rotation of the cam rod  100 , which has a protrusion (pin)  116  that abuts the stop  112  when the cam rod  100  is in the clamping position. 
     The nonlimiting embodiment of the camming portion  106  shown in the drawings further comprises a planar surface  110 , represented as lying on a chord of the otherwise circular cross-sectional outline defined by the camming portion  106 . As seen in  FIG. 12 , the planar surface  110  faces away from the clamp  81  when the camming portion  106  is in the clamping position. The planar surface  110  is preferably present on the camming portion  106  to provide greater clearance for slices that travel over the knife  70  and the outer surface of the clamp  81  as the slices exit the cutting head  62 . 
     The result of rotating the camming portion  106  of the rod  100  to its release position (counterclockwise in  FIGS. 12 and 13 ) is depicted in  FIGS. 14 and 15 , the former of which shows the camming portion  106  as being rotated out of engagement with the clamp  81  to release the force that had been applied by the rod  100  against the clamp  81 . In the release position, which is represented in the drawings as the result of rotating the camming portion  106  about ninety degrees from its clamping position, the camming portion  106  is at an intermediate distance from the knife holder  80  due to its eccentricity. The camming portion  106  can be seen to have engaged the rim of the hole  104  in the clamp  81 , causing the clamp  81  to pivot radially outward about its pivot (fastener  86 ) and disengage the knife  70 . From  FIG. 14 , it should be apparent that rotating the camming portion  106  about 180 degrees from the clamping position would result in the camming portion  106  being at its greatest distance from the knife holder  80 . However, the rotation of the cam rod  100  is limited by a stop  114  defined by the support ring  74 , which the rod protrusion  116  abuts when the cam rod  100  is in the release position. Even so, the clamping force applied by the camming portion  106  has been sufficiently released to enable the clamp  81  to be loosened and raised off the surface of the knife  70  as illustrated in  FIG. 14 . Because the knife  70  is no longer clamped between the knife holder  80  and clamp  81 , the knife  70  can be removed from the modular unit  76 , for example, through an opening  117  in the upper ring  74  seen in  FIG. 15 . From  FIGS. 12 through 15 , it can be appreciated that the flat knife  70  can be quickly secured and released by rotating the rod  100  between its clamping and release positions. 
       FIGS. 16 through 18  represent how knives having shapes other than flat can be utilized with the modular unit  76  to produce other than flat sliced products.  FIG. 16  represents a nonlimiting example of a “shaped” knife  70  having a cutting edge that defines a periodic pattern of peaks and valleys when viewed edgewise, and  FIG. 17  shows the shaped knife  70  of  FIG. 16  installed in the modular unit  76 . As evident from  FIG. 17 , the shaped knife  70  has a greater effective thickness than the flat knife  70  of  FIGS. 12 through 15 , to the extent that the release position of the clamp  81  depicted in  FIG. 14  may not be sufficient to release the shaped knife  70 . This issue can be addressed by modifying the placement of the stop  114  that determines the release position of the cam rod  100 . In particular,  FIGS. 17 and 18  represent the result of rotating the camming portion  106  beyond the ninety-degree counterclockwise rotation permitted by the stop  114  of  FIGS. 13 and 15 . As depicted in  FIGS. 17 and 18 , the cam rod  100  has been rotated about 180 degrees from the clamping position, resulting in its camming portion  106  being at its greatest distance from the knife holder  80 , which as evident from  FIG. 17  is sufficient to enable the clamp  81  to release the shaped knife  70 . Because the knife  70  is no longer clamped between the knife holder  80  and clamp  81 , the knife  70  can be removed from the modular unit  76 , for example, through the opening  117  in the upper ring  74  as seen in  FIG. 18 . 
       FIGS. 19 and 20  provide two perspective views to further illustrate different locations of the stop  114  resulting from the support ring  74  of the cutting head  62  being configured for clamping either flat knives  70  ( FIG. 19 ) or shaped knives  70  ( FIG. 20 ). From  FIGS. 12 through 20 , it should be evident that the extent to which the cam rod  100  is able to accommodate flat and shaped knives  70  can be tailored by the location of the stop  114 , without necessitating modifications to the modular unit  76  itself. For example, the support ring  74  may be replaced or its stop  114  relocated or otherwise modified in an appropriate manner. However, a more optimal clamping effect can be achieved by appropriately shaping the knife holder  80  and clamp  81  to be complementary to the shape of the knife  70 . The modular unit  76  is able to address this issue as a result of its modular construction, which permits holders  80  and clamps  81  of various configurations to be assembled to the mounting blocks  84 . This preferred aspect of the invention is illustrated in  FIGS. 21, 22 and 23 .  FIG. 21  represents the mounting blocks  84  and cam rod  100  as a subassembly  118  of the modular unit  76 . In  FIG. 22 , a flat knife  70  and a knife holder  80  and clamp  81  specifically configured for use with the flat knife  70  (together constituting the clamping assembly  78 ) have been assembled with the subassembly  118 , whereas  FIG. 23  represents the same subassembly  118  as having been assembled with a different clamping assembly  78  comprising a shaped knife  70  and a knife holder  80  and clamp  81  specifically configured to have periodic patterns of peaks and valleys that are complementary to peaks and valleys of the shaped knife  70 . 
       FIGS. 24 and 25  further illustrate the versatility of the modular unit  76  in terms of its adaptability for use with support rings  72  and  74  of various configurations and sizes (diameters). In particular, the placements of the mounting blocks  84  of the units  76  differ with respect to the support rings  72  in  FIGS. 24 and 25 . The trailing edges  96  of the gates  90  in  FIG. 25  create larger gate openings  120  with their respective succeeding knives  70 , causing the knives  70  in  FIG. 25  to produce much thicker slices than what is produced with the identical units  76  shown in  FIG. 24 . 
       FIGS. 26 through 33  contain various views representing a modular unit in accordance with another nonlimiting embodiment of the invention. For convenience, identical reference numerals are used in  FIGS. 26 through 33  to denote the same or functionally related elements described for the embodiments of the modular unit  76  of  FIGS. 8 through 25 . In view of similarities between the embodiments, the following discussion of  FIGS. 26 through 33  will focus primarily on aspects of the embodiment shown therein that differ from the modular units  76  of  FIGS. 8 through 25  in some notable or significant manner. Other aspects of the embodiment of  FIGS. 26 through 33  that are not discussed in any detail can be, in terms of structure, function, materials, etc., essentially as was described for the modular units  76  of  FIGS. 8 through 25 . 
     The modular unit  76  of  FIGS. 26 through 33  includes means for inhibiting deflection of the camming portion  106  away from the knife holder  80  when the cam rod  100  is in the clamping position. In the embodiment shown in  FIGS. 26 through 33 , the deflection inhibiting means comprises complementary features  122  that is configured to] that minimize the extent to which the camming portion  106  of the cam rod  100  can deflect when engaged with and applying a clamping force to the clamp  81 . In doing so, the complementary features  122  may also be capable of promoting a more uniform clamping force applied by the clamp  81  along the length of the knife  70 . Deflection of the camming portion  106  is limited by interlocking a latch  124  carried on the camming portion  106  with a catch  126  provided by the knife holder  80 . In the nonlimiting embodiment shown in the drawings, the latch  124  is depicted as a pin or bolt threaded into or otherwise secured to the camming portion  106 , and the catch  126  is depicted as a slot defined in the knife holder  80 , though it is foreseeable that other complementary means could be employed for interlocking the camming portion  106  with the knife holder  80  to prevent the camming portion  106  from deflecting away from the camming portion  106 , and such other means are within the scope of the invention. 
       FIG. 26  shows the knife  70 , knife holder  80 , and clamp  81  installed on the modular unit  76  and the cam rod  100  in its clamping position.  FIG. 27  is an identical view but with the clamp  81  removed to more fully reveal the knife holder  80 . FIG.  28  shows the modular unit  76  of  FIG. 27  from a different angle, and  FIG. 29  is an identical view to  FIG. 28  but shows the cam rod  100  in its release position. The latch  124  extends radially from the camming portion  106  of the rod  100  so that rotating the cam rod  100  between its clamping position ( FIGS. 26-28 ) and its release position ( FIG. 29 ), causes the latch  124  to rotate into ( FIGS. 30, 32, and 33 ) and out of ( FIG. 31 ) engagement with the catch  126 , respectively. 
     The embodiment of the latch  124  represented in  FIGS. 26 through 33  comprises a shank  124   a  and a head  124   b  that is wider than the shank  124   a .  FIGS. 30 through 33  show that the latch  124  engages with the catch  126  as a result of the shank  124   a  and head  124   b  of the latch  124  initially entering and traveling through the catch  126 , and the shank  124   a  subsequently entering a restricted (narrower) portion  126   a  of the catch  126  such that the head  124   b  engages a shoulder  126   b  formed by the restricted portion  126   a  opposite the camming portion  106 . To facilitate this action, the entrance  126   c  to the restricted portion  126   a  of the catch  126  can be seen in  FIGS. 30 and 31  to be sloped and more preferably rounded to have a radius of curvature, creating a ramp that approximates the arcuate path that the latch head  124   b  travels. Because the clamp  81  overlays the holder  80 , a complementary slot  128  is provided in the clamp  81  and aligned with the catch  126  in the holder  80  so that the latch  124  is able to freely enter the catch  126 . To maximize its effectiveness, the latch  124  is preferably located roughly at the center of the length of the camming portion  106  between the mounting blocks  84 , though such a location is not required. It is also within the scope of the invention to utilize any number of complementary latches  124  and catches  126  along the lengths of the camming portion  106  and knife holder  80 . 
     The drawings show the catch  126  as being provided as a removable and replaceable insert  130  installed in the knife holder  80 , so that the physical properties and dimensions of the catch  126  can be tailored for interacting with the latch  124 . The insert  130  is represented as being removably attached with threaded fasteners  132 , though other means for securing the insert  130  to the knife holder  80  are also within the scope of the invention. As evident from comparing  FIGS. 30 and 31 , the eccentricity of the camming portion  106  and the dimensions of the latch  124  and catch  126  (and insert  130  if employed) are coordinated to provide the latching action that enables the complementary features  122  to inhibit if not eliminate any deflection of the camming portion  106  by the process of engaging and clamping the clamp  81  between the camming portion  106  and knife holder  80 . The dimensional cooperation of the camming portion  106  and catch  126  can be tailored by altering the dimensions of the latch  124 , for example, by adjusting the extent to which the latch  124  is threaded into the camming portion  106 . 
     While the invention has been described in terms of specific or particular embodiments, it should be apparent that alternatives could be adopted by one skilled in the art. For example, the machine  10 , cutting head  62 , impeller  14 , modular units  76 , and their respective components could differ in appearance and construction from the embodiments described herein and shown in the drawings, functions of certain components could be performed by components of different construction but capable of a similar (though not necessarily equivalent) function, and various materials could be used in the fabrication of the machine  10 , cutting head  62 , impeller  14 , modular units  76 , and their respective components. As such, it should be understood that the above detailed description is intended to describe the particular embodiments represented in the drawings and certain but not necessarily all features and aspects thereof, and to identify certain but not necessarily all alternatives to the represented embodiments and described features and aspects. As a nonlimiting example, the invention encompasses additional or alternative embodiments in which one or more features or aspects of a particular embodiment could be eliminated or two or more features or aspects of different embodiments could be combined. Accordingly, it should be understood that the invention is not necessarily limited to any embodiment described herein or illustrated in the drawings. It should also be understood that the phraseology and terminology employed above are for the purpose of describing the illustrated embodiment, and do not necessarily serve as limitations to the scope of the invention. Therefore, the scope of the invention is to be limited only by the following claims.