Patent Document

CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of, and claims priority only to U.S. patent application, Ser. No. 09/032,388, filed Feb. 27, 1998 which is a continuation in part of Ser. No. 08/476,096, filed Jun. 7, 1995, U.S. Pat. No. 5,662,284, which is a division of Ser. No. 08/069,874, filed Jun. 1, 1993, U.S. Pat. No. 5,484,112. 
    
    
     BACKGROUND 
     The present invention relates to systems for shredding materials and, more particularly, to shear shredders in which cutting elements reduce material size. 
     Shear shredders are well known and are commonly used to reduce material size so that the overall volume of material is reduced for storage or transportation, or so that particle size of the material is reduced to promote burning or combustion of the material in an incinerator or kiln. The most common application for shear shredders is in the field of waste disposal; shear shredders are particularly effective in reducing such items as rubber vehicle tires to chip sizes which promote the burning of the tire material. 
     A typical shear shredding system is disclosed in U.S. Pat. No. 4,844,363 and includes a support frame which has an open top and bottom and houses a pair of shredder blade assemblies. Each shredder blade assembly includes a central shaft and a plurality of individual, disk-shaped cutter elements. The cutter elements are spaced apart from each other on the shaft so that a pair of cutter assemblies may be positioned so that the cutter elements mesh with each other. The shredder blade assemblies are counter-rotated relative to each other by a single drive motor and gearbox. 
     Such shredder systems include a feed hopper which is mounted on top of the housing and communicates with the open top of the support frame. The feed hopper includes a feed ram which is protected within the hopper by its own housing and includes a ram face which is reciprocated toward and away from the open top of the support frame and cutting elements by a double-acting cylinder. 
     It is typical with all such shredder systems that the cutter assemblies are difficult to insert and remove for maintenance, which results in relatively long periods of down time. Such down time subtracts from the productivity of the shear shredder in processing waste material. Another disadvantage with presently-known shear shredder systems is that the systems must be custom-designed for a particular application. That is, the major components, such as the cutter assemblies, support bearings, drive motors and housing walls cannot be interchanged and reassembled to form shear shredders of different configurations. 
     Accordingly, there is a need for a shear shredder design in which components, such as the shear cutter assemblies, can be removed and inserted in the field with a minimum of down time. Further, there is a need for a shear shredder having a feed ram which collapses when not in use to provide a maximum opening to the cutter elements. There is also a need for a shear shredder which is of modular construction such that an inventory of components can be maintained to be assembled into a number of different shredder configurations. 
     SUMMARY 
     The present invention is a modular shear shredder in which the cutter elements are mounted on shear cartridges which can be inserted and removed from the shredder housing sidewardly by moving a side wall section, thereby eliminating the need for removal or disassembly of bearings, gear drives or the feed hopper. The shear cartridge includes a shaft which supports a plurality of cutter elements that are held in position by end caps which are mounted on the ends of the shaft. The end caps have flat end surfaces which are adapted to be connected to either support bearings or drive motors. Consequently, there is no need to provide an inventory of specialized end caps which are needed for particular types of connections. 
     The shear cartridges are mounted within a support frame having opposing, removable side walls and removable end walls. The side walls are shaped such that the shear cartridges are insertable and removable through the openings formed by the removal of the side walls. The shear cartridges are connected either to drive motor shafts or support bearings mounted on the support frame end walls and are suspended between the motors and/or bearings. Accordingly, removal of the shear cartridges is accomplished by removal of the side wall and subsequent disengagement of the shear cartridge from the bearings and/or drive motors to which it is attached. 
     The end walls are modular and are shaped to support either support bearings or hydraulic drive motors. Consequently, a shear shredder having a pair of meshing shear cartridges can be designed such that a pair of drive motors drives each shear cartridge (making four drive motors for the system), or such that each shear cartridge is driven by a single drive motor at one end and is supported by a support bearing at the opposite end. 
     In the preferred embodiment, each shear cartridge of a dual cartridge system is driven by a pair of hydraulic drive motors. The hydraulic drive motors are each driven by a single, dedicated hydraulic pump. A pair of electric motors drives the pumps and the pumps are arranged such that each motor drives two pumps, and each of the pumps driven by a given motor is connected to a hydraulic drive motor on a different cartridge. With such an arrangement, should one shear cartridge become immobilized due to a jam, the entire motive force of the electric drive motors which power the pumps is dedicated to the single jammed shear cartridge so that the extra power operates to free the jam. 
     Also in the preferred embodiment, the removable side walls each support a plurality of comb elements which are spaced to mesh with the cutter elements of a shear cartridge. Accordingly, removal of the side wall disengages the comb elements from the cutter elements on a shear cartridge, thereby facilitating the replacement of the shear cartridge as well as the replacement of the comb elements. The comb elements are easily removable from the side wall on which they are mounted. 
     The preferred embodiment of the modular shear shredder includes a feed hopper having a feed ram mounted within the hopper. The feed ram includes a double-acting cylinder which advances and retracts the ram relative to the open top of the support frame, a ram face which is pivotally attached to the cylinder, and a second cylinder which pivots the ram face to an operative position, where it is positioned to urge material in the hopper toward the shear cartridges, or to a collapsed position in which the ram face is pivoted against the adjacent side wall of the hopper. The ram face includes a ram face shield which is pivotally attached to the ram face and extends upwardly to be pivotally attached to a housing which encloses the second cylinder which pivots the ram face. This face shield prevents material within the hopper from falling behind the ram face. The ram face, ram face cylinder and ram face cylinder housing are all mounted on a slide plate which is positioned adjacent to the side wall of the hopper. The primary cylinder, which advances the ram face, is mounted outside the hopper and therefore is easily accessible for maintenance and replacement. 
     Although described as a shear shredding apparatus, it will be apparent to those of ordinary skill in the art that the novel aspects of the present invention apply to other material processing apparatuses having a pair of co-acting, substantially parallel, counter-rotating rotor assemblies, such as briquetting apparatuses, grinding apparatuses and the like. In particular, it will be a conventional exercise for those of ordinary skill in the art to replace the shear cartridges with counter-rotating, co-acting briquette rolls, grinding rolls and the like. 
     The present invention also provides a modular material processing apparatus which comprises a housing including a frame, the frame defining a pair of oppositely facing lateral ends and a pair of oppositely facing longitudinal sides; a pair of co-acting, substantially parallel, counter-rotating roller assemblies, each of the roller assemblies including a substantially cylindrical, material processing roller member mounted to a rotating shaft extending substantially parallel with the longitudinal sides; a first support assembly mounted to one of the lateral ends of the frame, the first support assembly including a fixed support and an adjustable support, each of the fixed and adjustable supports supporting a corresponding one of the roller assemblies; and a second support assembly mounted to the other one of the lateral ends of the frame, the second support assembly including a fixed support and an adjustable support, each of the fixed and adjustable supports supporting a corresponding one of the roller assemblies. Each of the first and second support assemblies include a fixed support block retaining the fixed support; an adjustable support block retaining the adjustable support and being laterally slidable with respect to the fixed support block; a shim positioned on a lateral side of the adjustable support block, between the adjustable support block and a fixed member of the support assembly; and a lock for securing the adjustable support block and shim to the fixed member during normal operation of the material processing apparatus. Accordingly, the lateral distance between the fixed support and the lateral support on each of the first and second support assemblies may be adjusted by changing the thickness of the shim. 
     Accordingly, it is an object of the present invention to provide a modular material processing apparatus having a roller member which can be attached and removed with a minimum of down time; a modular material processing apparatus having removable side walls to facilitate replacement of roller members; a modular material processing apparatus having modular end walls are adapt to support either support bearings or hydraulic drive motors; a modular material processing apparatus having a hydraulic drive system in which the power of the hydraulic motors is fully devoted to a jammed roller member; a modular material processing apparatus having a feed hopper with a feed ram which collapses to maximize the feed hopper opening when the ram is not in use; a modular material processing apparatus providing simple and secure adjustment of the distance between the counter-rotating, material processing roller members; a modular material processing apparatus which is rugged in construction; and a modular material processing apparatus which is made of modular components that can be assembled in a variety of configurations. 
     Other objects and advantages of the present invention will be apparent from the following description, the accompanying drawing and the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a modular shear shredder of the present invention; 
     FIG. 2 is a perspective view of the support frame and shear cartridge assembly of the shear shredder of FIG. 1; 
     FIG. 3 is an exploded, perspective view of the shear shredder of FIG. 1; 
     FIG. 4 a  and FIG. 4 b  is an exploded, perspective view of a shear cartridge of the shear shredder of FIG. 1; 
     FIG. 5 a  and FIG. 5 b  is an exploded, perspective view of an end wall of the shear shredder of FIG. 1 in which the drive motors have been removed; 
     FIG. 6 is a schematic diagram of the hydraulic circuitry of the shear shredder of FIG. 1; 
     FIG. 7 is a side elevation in section of the feed hopper of the shear shredder of FIG. 1, in which the ram feed is shown in the operative position; 
     FIG. 8 is the hopper of FIG. 7 in which the ram feed is in a collapsed position; 
     FIG. 9 is an exploded, perspective view showing the feed ram of the shear shredder of FIG. 1 in which an access plate covering the primary cylinder of the ram feed has been removed; 
     FIG. 10 is a perspective view of the hopper of the shredder of FIG. 1, broken away to show feed ram components; 
     FIG. 11 is an exploded, perspective view of a briquetting apparatus incorporating an alternate embodiment of the present invention; 
     FIG. 12 is a perspective view of the briquetting apparatus of FIG. 11; 
     FIG. 13 is an elevational, cross-section view of the apparatus of FIG. 11, taken along lines  13 — 13  of FIG. 12; 
     FIG. 14 is an exploded, perspective view of an adjustable bearing housing according to an embodiment of the present invention; and 
     FIG. 15 is an elevational, front view of the adjustable bearing housing of FIG.  14 . 
    
    
     DETAILED DESCRIPTION 
     As shown in FIGS.  1 . and  3 , the shear shredder of the present invention, generally designated  10 , includes a support frame  12 , which is mounted above grade on four support legs  14 . The support legs  14  are part of a base frame  16  which supports the frame  12 . The support frame  12  receives removable side walls  18 ,  20  and removable end housings  22 ,  24 . The side walls  18 ,  20  preferably are bolted to the frame  12 , as are the end housings  22 ,  24 . 
     The support frame  12 , side walls  18 ,  20  and end wall housings  22 ,  24  form an enclosure, generally designated  26 , having an open top  28  which allows material to enter the interior grinding chamber  30  of the shear shredder. A hopper  32  having downwardly-converging side walls  34 ,  36 ,  38 ,  40  is mounted on the shredder housing  26  and communicates with the open top  28 . 
     The grinding chamber  30  is defined by the side walls  18 ,  20  and grinding chamber end walls  42 ,  44 . The frame end walls  46 ,  48  are removably attachable to the ends of the support frame  12  by bolts or machine screws (not shown), and support drive motors  50 ,  52 ,  54 ,  56 , respectively. The end walls  46 ,  48  are attached to U-shaped brackets  57  which are machined for precision and welded to the frame  12  in precise alignment with respect to each other. In the preferred embodiment, the walls  46 ,  48  are dowelled for location. 
     The side walls  18 ,  20  are also removably attachable to the support frame  12  by bolts or machine screws, (not shown). Each of the side walls  18 ,  20  supports a plurality of spaced comb elements  59 . Comb elements  59  are separate by spacers  60  and are retained on side walls  18 ,  20  by rails  61 , bolted to the walls, which capture tabs protruding from the base of the elements. 
     A pair of shear cartridges  62 ,  64  are mounted within the support frame  12 . As shown in FIGS. 2 and 4, each shear cartridge includes a hexagonal shaft  66  on which is mounted a plurality of cutter elements  68 , each of the cutter elements being separated from its neighbor by a spacer ring  70 . The cutter elements  68  and spacer rings  70  each include hexagonal central openings to prevent rotation relative to the shaft  66 . Outside of the array of cutter element  68  and spacers  70  are small  72  and large  74  stack tighteners. The small and large stack tighteners  72 ,  74  each have a central, hexagonal opening to receive the shaft  66 , and large stack tighteners  74  include a peripheral flange  76 . The array of cutter elements  68 , spacer  70  and stack tighteners  72 ,  74  are held on the shaft  66  by end caps  78 ,  80 . End caps  78 ,  80  are retained on the ends of the shaft  66  by screws  82 ,  84 , respectively. Jam nut and wedge bolt combinations  86  extend between the end cap  80  and stack tightener  72 ,  74 . The jam nut and wedge bolt combinations are adjusted to urge the stack tighteners  72 ,  74  inwardly toward the shaft  66  to tighten the cutter elements  68  and spacers against each other. 
     As shown in FIGS. 1 and 2, the shear cartridges  62 ,  64  are positioned within the support frame  12  so that the stack tighteners  72 ,  74  are adjacent to the grinding chamber end walls  42 ,  44 . The flange on stack tightener  74  is adjacent to a spacer  70  and serves as a shield to prevent contaminants from passing through the wall  42 . The walls  42 ,  44  each include inserts  88 ,  90 ,  92 ,  94  which complete the continuity of the end walls  42 ,  44  to define the grinding chamber  30 . 
     Each of the hydraulic drive motors  50 - 56  includes a flat attachment plate  96  mounted on its output shaft. The flat plates  96  bolt to the faces  98  of the end caps  78 ,  80  of the shear cartridges  62 ,  64 . 
     As shown in FIG. 5 for end wall  46 , the end walls  46 ,  48  include openings  100 ,  102  which receive the housings  104  of the motors  54 ,  56 . The housing flanges  106  of the motors  54 ,  56  are ground to permit close spacing of the motors and are attached to the walls by bolts or machine screws (not shown). 
     As shown in FIG. 10, the hopper  32  includes a feed ram, generally designated  108 , which is mounted on hopper side wall  34 . Side wall  34  includes longitudinal reinforcing bars  110 ,  112  and lateral struts  114 ,  116 , which extends between the reinforcing bars, and frame and opening  118  formed in the side wall  34 . A primary double-acting cylinder  120  is mounted so that a first cylinder rod  122  is attached to lateral strut  116  and second and third rods  124  are attached to a slider plate  126  (see also FIGS.  7  and  10 ). The cylinder  120  is covered by access plate  127 . Such a cylinder  120  is shown in greater detail in co-pending U.S. patent application Ser. No. 07/993,123, filed Dec. 21, 1992, the disclosure of which is incorporated herein by reference. 
     The slider plate  126  is shaped to cover the opening  11 - 8  completely when cylinder rod  122  is extended and retracted. 
     Secondary cylinders  128  (See FIG. 10) are pivotally mounted on slider plate  126  and include rods  130  which are Pivotally attached to a ram assembly, generally designated  132 . Ram assembly includes a ram face  134  which is pivotally attached to a support frame  136  having legs  138  which telescope into sections  140  of the slider plate  126 . 
     A ram shield  142  is pivotally connected to the ram face  134  at a lower end and is pivotally connected to the slider plate  126  at an upper end. The slider plate and ram assembly  132  are covered by a plate  144 . The plate  144  and shield  142  act together to prevent waste material from falling behind the ram face  134 . 
     As shown in FIG. 8, when the secondary cylinder  128  is retracted, the ram assembly is drawn upwardly relative to the slider plate  126 . This causes the ram face  134  to pivot toward the side wall  34  of the hopper  32 . At the same time, the shield  142  pivots relative to the slider plate  126  as well, and forms a substantially planar surface with plate  144 . In this collapsed configuration, the feed ram  108  presents a low profile and a minimal obstruction within the hopper  32 . 
     As shown in FIG. 7, when it is desired to activate the feed ram  108 , the secondary cylinders  128  are actuated to extend their rods  130 , thereby displacing the ram assembly downwardly relative to the slider plate  126 . This relative movement causes the ram face  134  to pivot outwardly to an operative position. The ram face may then be reciprocated relative to the hopper  32  and side wall  34  by primary cylinder  120  to urge material downwardly through the open top  28  and into the grinding chamber  30  (See FIG. 1) of the shear shredder  10 . 
     The system for powering the various components of the shear shredder  10  is shown schematically in FIG. 6. A pair of drive motors  146 ,  148  each power a pair of pumps  150 ,  152 ,  154 ,  156 , respectively. In addition, electric drive motor  148  powers pump  158  which supplies hydraulic pressure through valves  160 ,  162  to the cylinders  120 ,  128  in the feed ram  108  (See also FIG.  10 ). 
     Pumps  1 - 50 ,  152  are connected to and supply pressurized hydraulic fluid to hydraulic cartridge drive motors  50 ,  52 , respectively. Similarly, hydraulic pumps  154 ,  156  are connected to and supply pressurized hydraulic fluid to hydraulic cartridge drive motors  54 ,  56  respectively. Consequently, each of the shear cartridges  62 ,  64  receives power from both electric drive motors  146 ,  148 . Specifically, shear cartridge  62  is rotated by drive motors  54 ,  50  and shear cartridge  64  receives rotational power from drive motors  56 ,  52 . 
     As a result of this arrangement, should either of the shear cartridges  62 ,  64  become jammed, the power from both of the motors  146 ,  148  is directed to the hydraulic drive motors powering that shear cartridge. Thus, smaller electric drive motors  146 ,  148  may be used since their power is combined in operational conditions which require greater power. 
     As a result of the structure of the shear shredder, the insertion and replacement of the shredder cartridges  62 ,  64  is facilitated. For example, should it be necessary to replace shear cartridge  62  in the field, the following sequence of steps is performed. First, side wall  18  is removed from the support frame  12 , which disengages the associated comb elements  59  from the cutter elements  68  of cartridge  62 . Inserts  88 ,  92  are unbolted from engagement with end walls  42 ,  44 . If necessary, the stack tighteners  72 ,  74  are loosened by appropriate adjustment of the screws  86 , which allows the cutter elements  68  to separate from the spacer elements  70  slightly. This step may be performed prior to the removal of side wall  18  in order to facilitate disengagement with the comb elements  60 . 
     The cartridge  62  is then supported by a jack (not shown) to cradle it and the end caps  78 ,  80  are unbolted from their connection to the face plates  96  of the hydraulic drive motors  50 ,  54 . The cartridge  62  can then be removed from the support frame  12  by a fork lift or the like. 
     The end walls  46 ,  48  are also easily removable. In order to assure proper alignment, in the preferred embodiment, the end walls  46 ,  48  are located in position with high precision by dowel pins (not shown). In order to remove the end walls  46 ,  48 , they are unbolted, the dowel pins removed and the end walls, along with the drive motors  50 - 56  can be lifted upwardly by a crane. Of course, the upward removal of the end walls  46 ,  48  requires removal of the end wall housings  22 ,  24  from the support frame  12 . 
     It is apparent, therefore, that the cartridges  62 ,  64  are modular in design and can be reversed end-for-end and inserted in the support frame  12 , if required. Further, the shear cartridges  62 ,  64  can be of identical construction and selected from among an inventory of identical shear cartridges. Similarly, the end walls  46  and  48  and motors  50 - 56  are modular in construction and can be selected from among an inventory of substantially identical components. For proper alignment of the end walls  46 ,  48  which is desired to effect a proper alignment of the shear cartridges  62 ,  64 , the portions of the support frame  12  which receive the end walls  46 ,  48  only need to be machined to a high precision, and not other components of the frame. 
     Also in the preferred embodiment, the hydraulic drive motors  50 ,  52 ,  54 ,  56  are controlled by the use of swash plates, rather than valves, which promotes efficiency of operation. 
     Although described above as a shear shredding apparatus, it will be apparent to those of ordinary skill in the art that the novel aspects of the present invention apply to other material processing apparatuses having a pair of co-acting, substantially parallel, counter-rotating rotor assemblies, such as briquetting apparatuses, grinding apparatuses and the like. In particular, it will be a conventional exercise for those of ordinary skill in the art to replace the shear cartridges  62 ,  64  with counter-rotating, co-acting briquette rolls, grinding rolls and the like. 
     FIGS. 11-13 illustrate an alternate embodiment of the present invention  164 , which provides a first roller assembly that is laterally adjustable with respect to a second fixed roller assembly. The roller assemblies illustrated in this alternate embodiment are briquetting rolls, however, as described above is within the scope of the invention to use shear shredding cartridges, grinding rolls, and any other similar material processing roll as will be known to those of ordinary skill in the art. 
     As shown in FIGS. 11-13, the material processing apparatus  164  includes a support frame  166  which receives removable side walls  168 ,  170  and removable end bearing housings  172 ,  174 . The side walls  168 ,  170  preferably are bolted to the frame  166 , as are the end bearing housings  172 ,  174 . The support frame  166 , side walls  168 ,  170  and end bearing houses  172 ,  174  form an enclosure, generally designated  176 , having an open top  178  which allows material to enter the material processing chamber  180  of the area processing apparatus  164 . Material processing chamber  180  is defined by side walls  168 ,  170  and processing chamber end walls  182 ,  184 . The end bearing housing  174  supports a pair of drive motors assemblies  186 ,  188 , where each drive motor assembly  186 ,  188  respectively includes bearing and shaft assembly  190 ,  191  a reversible hydraulic drive motor  192 ,  193  and a motor housing  194 ,  195 . The other end bearing housing  172  supports a pair of bearing assemblies  196 ,  198 . It will be apparent to one of ordinary skill in the art that the bearing assemblies  196 ,  198  may be replaced by a second pair of drive motor assemblies as described above. The bearing assemblies  190 ,  191 ,  196 ,  198  include unique stave bearings  199 , which are described in detail in U.S. Pat. No. 6,000,852. 
     A pair of substantially cylindrical, material processing roller assemblies  200 ,  202  are mounted within the support frame  166 . End caps  208 ,  209  are retained on the ends of each roller assembly  200 ,  202 . The hexagonal shaft  210  of each bearing/shaft assembly  190 ,  191 ,  196 ,  198  extends through a cylindrical hole  211  in the respective end bearing housing  172 ,  174 , and is coupled to a corresponding attachment plate  212  . The attachment plates  212  are, in turn, bolted to the faces of the end caps  208 ,  209  of the material processing roller assemblies  200 ,  202 . 
     The walls  182 ,  184  each include inserts  214 ,  216 , ( 218  not shown),  220  to complete the continuity of the end walls  182 ,  184  and to define the material processing chamber  180 . As is discussed in greater detail below, each end bearing housing  172 ,  174  includes a fixed bearing support member  222  and an adjustable bearing support member  224 , which is laterally adjustable with respect to the fixed bearing support member  222 . Finally, the apparatus  164  includes removable top and bottom panels  226 ,  228 , respectively for isolating the material processing chamber  180  from the remainder of the material processing apparatus  164 . 
     As shown in FIGS. 14 and 15, each end bearing housing  172 ,  174  includes a fixed bearing support  222  and an adjustable bearing support  224 . Fixed bearing support  222  is integral with or fixedly attached to a frame  230 . The frame  230  includes a lateral surface  232  extending laterally from the fixed support member  222  slidably receiving the adjustable support member  224 , and the frame further includes a fixed member  234  distal from the bearing support  222  and perpendicular to the lateral surface  232 . The frame further includes a top opening  236  for receiving the adjustable bearing support. 
     When the adjustable bearing support  224  is seated on the lateral surface  232 , a shim  238  is positioned on a lateral side  240  of the adjustable bearing support, between the adjustable bearing support  224  and the fixed bearing support  222 . On the opposite lateral side  242  of the adjustable bearing support a hardened plate  244  and a torque plate  246  are positioned between the adjustable bearing support  242  and the fixed member  234  of the frame  230 . The torque plate  246  includes a plurality of threaded bores  248  extending laterally therethrough for receiving a corresponding plurality of threaded bolts  250 . The bolts  250  are received through a lateral opening  252  extending through the side of the frame  230 . 
     As shown in FIG. 15, as the bolts  250  are threaded through the torque plate  246  and abut against the hardened plate  244  the continuous turning of the bolts causes the torque plate  246  to abut against the fixed member  234  of the frame  230 . Accordingly, further tightening of the bolts  250  causes the hardened plate  244  and torque plate  246  to be forcefully separated from one another, and in turn causes the hardened plate  244  to apply lateral pressure against the adjustable bearing support  224  in the direction of the shim  238  and fixed bearing support  222 . And upon sufficient tightening of the bolts  250 , the adjustable bearing support  224  will be fixed with respect to the fixed bearing support  222 , having the shim  238  being fixed therebetween. Accordingly, by adjusting the thickness of the shim  238 , the operator will be able to adjust the lateral separation between the fixed bearing support  222  and the adjustable bearing support  224 . 
     For example, when the present apparatus  164  is used as a briquetting machine, the new briquetting rolls  200 ,  202 , are installed into the apparatus  164  a new shim having a predefined thickness will be likewise mounted between the fixed bearing support  222  and the adjustable bearing support  224 . Thereafter, as the briquetting rolls wear down, the operator will be able to move the briquetting rolls closer together by loosening the bolts  250 , removing the shim  238  from between the fixed bearing support  222  and the adjustable bearing support  224 , machining the shim  238  to the desired thickness, re-inserting the shim  238  between the fixed bearing support  222  and the adjustable bearing support  224 , and then re-tightening the bolts  250 . 
     While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that other forms of apparatus may be employed without departing from the scope of the invention.

Technology Category: 7