Abstract:
A tumbling unit such as a casting shake-out unit, rotary media drum, sand reclaimer or the like, is provided. The tumbling unit includes a cylindrical outer shell and a cylindrical inner shell. The inner liner is formed of a series of interfitting segments. The segments each have an inner surface, an outer surface, side edges, a front edge, a back edge, and a vane extending from the outer surface. The side edges of the segments have a groove formed therein which extends the length of said the edges. The grooves of neighboring segments define channel between the segments. A pin or liner lock key is received in the channel to urge the neighboring segments apart to form a tight interfit among the segments in a row of the liner. The retaining pin has a body having side surfaces, a top surface, and a bottom surface. A hole extends through the pin body and receives a dowel, which is sized to extend from opposite sides of said pin body. The dowel is shaped and sized to be received in the grooves of the neighboring segments. An arm extends upwardly from the pin body top surface. The pin arm conforms in shape and size to the side profile of the vane, and is positioned on the pin body to be in alignment with the vane of the adjacent segments, to form a continuous vane on the outer surface of the liner. In another embodiment of the liner segments, the segments are secured to each other and to the outer cylinder of the tumbler.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation-in-part of co-pending application Ser. No. 09/398,286 filed Sep. 20, 1999, now U.S. Pat. No. 6,273,176. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     This invention relates to casting shake-out units used to separate or remove sand from castings, and in particular, to a liner which forms the inner surface of the shake-out unit. 
     In the formation of a tumbling mill, such as a casting shake-out unit, rotary separator, media drum, material drier, lump crusher reclaimer, blending drum, sand screen, or the like, it is desirable to form the inner surface of the mill from segments. Thus, when individual segments wear out, they can be replaced easily and rapidly without the need to incur a significant amount of downtime or expense. An example of a shake-out unit having segmented inner liners is shown in U.S. Pat. No. 3,998,262 with is assigned to the same assignee as the present invention, and which is incorporated herein by reference. As set forth in that patent, the inner cylinder forming the inner surface of the unit is formed from a series of interconnected modular components. The operation of that unit, for its intended purpose, has performed highly satisfactorily. However, when the casting shake-out unit is operated continuously, the wear on the components causes the components or segments to gradually loosen. This requires a retightening of the entire formed inner surface. This retightening operation requires that the operator incur a significant amount of down time. 
     It is desirable for the mill to operate for a longer period before the segments begin to loosen and separate. In U.S. Pat. Nos. 4,502,808, 5,638,887, and 5,638,890, all of with are assigned to the same assignee as the present invention and incorporated herein by reference, the side edges of the segments are grooved to define a channel between neighboring segments. A pin or bar is inserted in the channel. In a completed lining, the bars tend to urge the segments apart, thus creating a tight fit in the completed cylindrical lining. These have also worked well. However, the pins and the interlocking of the liner segments can still be improved. 
     BRIEF SUMMARY OF THE INVENTION 
     A tumbling unit such as a casting shake-out unit, rotary media drum, sand reclaimer or the like, is provided. The tumbling unit includes a cylindrical outer shell and a cylindrical inner shell. The inner liner is formed of a series of interfitting segments. The segments each have an inner surface, an outer surface, side edges, a front edge, a back edge, and a vane extending from the outer surface. The side edges of the segments have a groove formed therein which extends the length of said the edges. The grooves of neighboring segments define channel between the segments. To enable the segments to interfit, the segments include tongues on their segment front and back edges and cutouts in their corners. The tongues and cutouts are shaped and positioned to enable the segments to interfit with each other. 
     The pin or liner lock key is received in the channel to urge the neighboring segments apart to form a tight interfit among the segments in a row of the liner. The retaining pin has a body having side surfaces, a top surface, and a bottom surface. In one embodiment, a rib extends along each side surface which is shaped and sized to be received in the grooves of the neighboring segments. In a second embodiment, the rib is replaced with at least one dowel which extends through at least one opening in the pin body. The dowel extends from opposite sides of the pin, and the portions of the dowel extending from the pin are received in the grooves of the segments. An arm extends upwardly from the pin body top surface. When the pin is placed between two neighboring segments, it separates the segments. The pin arm conforms in shape and size to the side profile of the vane, and is positioned on the pin body to be in alignment with the vanes of the adjacent segments, to form a continuous vane on the liner. The pins have cutouts at opposite ends thereof which conform generally in size and shape to the profile of the segment cutouts. 
     In a second embodiment, the segments include a first and a second side, and a front and a back side. A first side flange extends along the first side; a second side flange extends along the second side; a front flange extends along the front side; and a back side flange extends along the back side. The flanges all have a width equal to approximately one-half the width of the segment body between the inner and outer surfaces of said segment body. The first side flange and bottom flange have a surface generally flush with one of the inner and outer surfaces of the segment; and the second side flange and the top flange have a surface generally flush with the other of the inner and outer surfaces of the segment. This gives the segment the appearance of two rectangles being placed on top of each other, with one rectangle being diagonally offset from the other rectangle. 
     In a third embodiment, the liner segments are provided with flanges extending along the side edges of the segments on the outer surface of the segments. The flanges include bolt holes which extend therethrough. When the segments are assembled together, the flanges of adjacent segments are adjacent each other, with their bolt holes aligned. A fastener, such as a bolt, pin, post, etc. is passed through the holes to retain the segments of a row of segments together. Holes are also placed in the bottom of the vane, at opposite ends of the vane. A pin, which is fixed to the outer cylinder, extends into the vane hole, to secure the segment to the outer cylinder. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 is a partial perspective end view of a tumbling unit which is partially exploded to show one segment and a pair of retaining pins removed and with inner riflings not shown for purposes of clarity; 
     FIG. 2 is a side elevational view of the pin; 
     FIG. 3 is an end elevational view of the pin; 
     FIG. 4 is an end elevational view of a pair of segments adjacent each other with a pin positioned between them; 
     FIG. 5 is an inner plan view of three segments positioned together; 
     FIG. 6 is a top plan view of an alternative embodiment of the inner liner segment; 
     FIG. 7 is a side elevational view of a pair of segments of FIG. 6 adjacent each other; 
     FIG. 8 is an inner plan view of three segments of FIG. 6 positioned together; 
     FIG. 9 is an front elevational view of an alternative embodiment for the pin; 
     FIG. 10 is a side elevational view of the pin of FIG. 9; 
     FIG. 11 is an end elevational view of a third embodiment of the liner segment partly in cross-section and showing a pin used to positionally secure the liner segment to an outer cylinder of the tumbler; 
     FIG. 12 is a side elevational view of the liner segment of FIG. 11; 
     FIGS. 13 and 14 are top and bottom plan views of the liner segment of FIG. 11; 
     FIG. 15 is a fragmentary view showing tow segments joined together; 
     FIG. 16 is a side elevational view of a tumbler assembled with liner segments of FIG. 11; 
     FIG. 17 is an end view of a liner lock key for use with the liners of FIG. 11; and 
     FIG. 18 is a side elevational view of the liner lock key of FIG.  14 . 
    
    
     Corresponding reference numerals will be used throughout the several figures of the drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The following detailed description illustrates the invention by way of example and not by way of limitation. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what we presently believe is the best mode of carrying out the invention. 
     A tumbling mill  1  is shown generally in FIG.  1 . Tumbling mill  1  is preferably a mill constructed and operated in the manner disclosed in the above noted U.S. Pat. No. 3,998,262 to remove sand from casting by tumbling the castings. As shown, the mill  1  generally includes an outer cylinder  3  and an inner cylinder  5 . The inner cylinder  5  is of a smaller diameter than the outer cylinder  3 , and the two cylinders define a space  7  between the cylinders. The inner liner or cylinder  5  is made of a plurality of interlocking segments  9  which fit together to form the cylinder  5 . Importantly, as described below, the segments  9  positively lock together so that segments will not fall out of the lining as they wear. This advantageously increases the time the mill may be continuously operated before it has to be shut down to tighten the inner liner  5 . 
     The segment  9  is similar to the segments described in the above noted U.S. Pat. No. 5,638,890, which is incorporated herein by reference. Each segment  9  includes a generally arcuate body  11  having an inner surface  13 , an outer surface  15 , side edges  17 , and front and back edges  19 . Each segment preferably covers approximately 35°-40° of arc. To space the segments  9 , and hence, the inner cylinder  5 , from the outer cylinder  3 , each segment  9  has diagonally extending ribs or vanes  21  formed its outer surface  15 . The vanes  21  are positioned on segment  9  so that when a plurality of the segments are connected to form inner cylinder  5 , the vanes from one segment abut respective vanes from neighboring segments to provide a continuous vane along the cylinder surface. The inner cylinder  5  is preferably perforated so that the sand which is separated from the castings may fall into the space  7  between the inner and outer cylinders. The segments  9  thus have a plurality of holes or perforations  22  formed therein to allow sand to fall into the space  7  between the inner and outer cylinders. A slot or groove  23  is formed along the side edges  17  to receive a pin  25  which spaces the segments apart in the completed inner cylinder to tighten the fit between the segments of the inner cylinder. The pin  25  is described in more detail below. The groove  23  extends the full length of the side edges  17 . 
     To enable the segments  9  to interlock with each other, each segment includes a tongue  31  extending from the approximate center of the front and back edges  19  and generally rectangular cutouts  33  at the four corners of the liner body  11 . The cutouts  33  define pockets  35  when two segments  9  are placed adjacent each other along their side edges  17 . The formed pocket receives the tongue  31  of a further segment  9  which is placed adjacent the two segments along the front and back edges  19  of the segments, as seen in FIG.  5 . The tabs  31  extend the full width of the body  11  between the inner and outer surfaces  13  and  15 . The body, however, includes a raised portion  36  (FIG. 4) on the outer surface  15  which covers the cutouts  33 . Thus, the pockets  35  are closed on one side. When the liner  5  is assembled, the raised portions or covers  36  rest on the tongues  31 , thereby interlocking the segments  9  of adjacent different rows of segments. 
     As seen in FIG. 5, the segments  9  include rifling  37  on their inner surfaces  13 . The rifling is not shown in FIG. 4 for purposes of clarity. In the completed lining, the rifling helps move castings through the mill. The rifling  37  is formed on the segments so that the rifling of one row of liner segments is off-set from the rifling of an adjacent row of liner segments. Thus, the rifling or ribs  37  do not form continuous ribs or rifling along the inner surface of the liner  5 . 
     The retaining pins  25  are positioned between the side edges  17  of adjacent or neighboring segments  9 . The pins  25  are shown in more detail in FIGS. 2 and 3. Each pin  25  includes an elongate, generally rectangular body  41  having side walls  43 , a top surface  45 , and a bottom surface  47 . The body  41  has a length substantially equal to the length of the segment side  17 . So that the pin will not interfere with the interlocking of the segments  9 , the pin body includes a cut out  49  on either end of the body. The cutout  49  corresponds in size and shape to the side profile of the cutouts  33  in the segments  9 . 
     A rib  51  extends along each side surface  43  of the pin body  41 . The ribs  51  are sized and shaped to be received in the grooves  23  in the segment sides  17 . Additionally, an arm  53  extends up from the pin body top surface  45 . As seen in FIG. 4, the arm  53  is positioned on the pin body  41  such that it is aligned with the vanes  21  of the liner segments  9  when the liner  5  is assembled. Thus, the arm  53 , as seen, is generally trapezoidal in side elevation (FIG.  2 ), and rectangular in front elevation (FIG.  3 ), which corresponds in size and shape to the side profile of the segment ribs  21 . Thus, the ribs  51  provide for a smooth transition between the vanes  21  of the segments  9 , as well as of the inner surfaces  13  of the segments  9 . 
     When the segments  9  are interconnected, the pins  25  tighten the liner or inner cylinder  5 , as set forth in the above noted U.S. Pat. No. 4,502,808, to lengthen the time before the segments come loose from each other due to continuous operation of the mill. The interconnection of the segments, in turn, prevents a segment from falling out when the pin wears. Thus, if a pin  25  wears, the interaction between the tongue  31  and its associated pocket  35  will prevent the segment from falling out from the inner cylinder  5 . Although the segment will be loose when the pin wears through, the segment will not fall out. This will allow the operator time to normally shut down the mill to insert a new pin or a new segment. 
     An alternative embodiment of the pin is shown in FIGS. 9 and 10. The pin  25 ′ includes an elongate, generally rectangular body  41 ′ having side walls  43 ′, a top surface  45 ′, and a bottom surface  47 ′. The body  41 ′ has a length substantially equal to the length of the segment side  17 . So that the pin will not interfere with the interlocking of the segments  9 , the pin body includes a cut out  49 ′ on either end of the body. The cutout  49 ′ corresponds in size and shape to the side profile of the cutouts  33  in the segments  9 . 
     The pin  25 ′ does not include a rib, as does the pin  25  of FIGS. 2 and 3. Rather, the pin  25 ′ includes openings  50  in the body  41 ′ which receive dowels  52 . The pin  25 ′ is shown with three openings  50 , spaced generally equally apart. For purposes of illustration, the two outer openings  50  are shown to be circular and the middle opening  50  is shown to be square. However, all the openings could be circular or they could all be square; or, the openings could be any other desired shape. Additionally, one opening or four or more openings  50  could be provided in the body  41 ′. The dowel  52  is shaped complimentarily to the holes, to be slidingly received in the holes  50 . The dowel  52  has a length, such that it will extend from the sides of the pin body  41 ′ and into the grooves  23  of the liner segments  9  when the liner is assembled. Additionally, an arm  53 ′ identical to the arm  53  of pin  25  extends up from the pin body top surface  45 ′. The pin  25 ′ is shown with three holes  50 —two holes near the ends of the body and one hole generally centered with respect to the body and generally aligned with the pin arm  53 ′. The body  41 ′ could be provided with more or fewer holes  50  is desired. 
     A second embodiment of the segments is shown in FIGS. 6-8. The segments  109  include a generally arcuate body  111  having an inner surface  113 , an outer surface  115 , a first side edge  117   a , a second side edge  117   b , a front edge  119   a , and a back edge  119   b . A first side flange  121  extends from the body along side  117   a  and a front flange  123  extends along the front edge  119   a . A second side flange  125  extends along side  117   b  and a back flange  127  extends along the back  119   b . The flanges  121 ,  123 ,  125 , and  127  have a top to bottom thickness of about % of the thickness of the segment body  111  between its inner and outer surfaces. The flanges  121  and  123  both have top surfaces which are continuations of the outer surface  115  of the segment body; and the flanges  125  and  127  have bottom surfaces which are continuations of the inner surface  113  of the segment body. Thus, as seen in FIG. 6, the body, in top plan, appears as two rectangles placed on top of each other and diagonally offset from each other. 
     To assemble the inner cylinder from the segments  109 , the segments are assembled with their flanges in overlapping relationship, as shown in FIGS. 7 and 8. As with the segments  9 , the overlapping relationship of the flanges of the segments  109  will prevent the segments from falling out of the inner cylinder as the segments become worn. Although not shown in the drawings, grooves can be formed in the edge of the flange  121  and in the body side  117   b  to accept the pin  25 . 
     A third embodiment of the liner segment is shown in FIGS. 11-16. The liner segments  209  include a generally arcuate body  211  having an inner surface  213 , an outer surface  215 , side edges  217 , and front and back edges  219 . Each segment preferably covers approximately 35°-40° of arc. To space the segments  209 , and hence, the inner cylinder  205  formed from the segments  209 , from an outer cylinder  203 , each segment  209  has diagonally extending ribs or vanes  221  formed on its outer surface  215 . The vanes  221  are positioned on segment  209  so that when a plurality of the segments are connected to form inner cylinder  205 , the vanes from one segment abut respective vanes from neighboring segments to provide a continuous vane along the cylinder surface. The inner cylinder  205  is preferably perforated so that the sand which is separated from the castings may fall into the space  207  between the inner and outer cylinders. The segments  209  thus have a plurality of holes or perforations  222  formed therein to allow sand to fall into the space  207  between the inner and outer cylinders. 
     To enable the segments  209  to interlock with each other, each segment includes a tongue  231  extending from the approximate center of the front and back edges  219  and generally rectangular cutouts  233  at the four corners of the liner body  211 . The cutouts  233  define pockets  235  (FIG. 15) when two segments  209  are placed adjacent each other along their side edges  217 . The formed pocket receives the tongue  231  of a further segment  209  which is placed adjacent the two segments along the front and back edges  219  of the segments, as discussed above in conjunction with the liner segment  9  of FIG. 1, and as shown in FIGS. 4 and 5. The tongues  231  extend the full width of the body  211  between the inner and outer surfaces  213  and  215 . The body, however, includes a raised portion  236  on the outer surface  215  which covers the cutouts  233 . Thus, the pockets  235  are closed on one side. When the liner  205  is assembled, the raised portions or covers  236  rest on the tongues  231 , thereby interlocking the segments  209  of adjacent different rows of segments. 
     To hold the liner segments  209  in place relative to each other in the formed inner liner  205 , the segments  209  include downwardly extending flanges  241  at the segment sides  217 . The flange extends along the segment sides  217  between the edges of the cutouts  233 . The flange  241  include bolt holes  243 . In the assembled liner  205 , the flanges  241  and their bolt holes  243  of adjacent segments  209  are aligned, a bolt  245  is passed through the holes  243  of the adjacent flanges  241 , and a nut is applied to the threaded end of the bolt to hold the segment in place. As can be appreciated, the segments of a single row of segments in the liner are secured together in this fashion. Although, adjacent rows are not secured together, they could be. Rather, the interaction of the tongues  231  of the segments of one row with the pockets  235  of the segments of the adjacent rows will substantially prevent slippage of one row of segments relative to another row of segments. 
     Additionally, holes  251  are formed in the bottom surfaces  253  of the segment vanes  221  at the lateral ends of the vane  221 . The holes  251  are sized to receive a pin  255 . The pin  255  has a head  257  which is welded to the outer cylinder  203  and a body  259  which extends radially inwardly from the outer cylinder  203  and into the hole  251  at the bottom of the vane  221 . The pin body  259  and the vane hole  251  are shaped complimentarily to each other. They can be circular, square, or any other desired shape. Use of the pins  255  anchors each liner segment  209  to the outer cylinder  203  in two places. With a pin  255  positioned at both ends of the vane of each segment  209 , the pin  255  will fix the relative position of the liner segments with respect to the outer cylinder  203 . Hence, the rows of segments  206  will not be able to mover relative to the outer cylinder  203 . Further, the interaction of the pins  255  (which are welded to the outer cylinder  203 ) with the segments  209 , will prevent one row of segments from moving relative to an adjacent row of segments. 
     The segments  209  are described as being assembled without the use of a liner lock key, such as the liner lock key  25  of FIGS. 2-3 or  9 - 10 . However, a liner lock key,  325 , such as shown in FIGS. 17-18 can be used. In this case, the segments are provided with a slot or groove in the side edges, similar to the slot or groove  23  of the liner segment  9  (FIG.  4 ). The key  325  is shown formed similarly to the key  25 , but could also be formed similarly to the key  25 ′ of FIGS. 9-10. The difference between the key  325  and the key  25  or  25 ′, is that the key  325  is provided with bolt holes  327  in the side wall  343  of the body  341 . The bolt holes  327  line up with the bolt holes  243  in the flanges  241 . The bolt  245  then passes through the bolt holes  243  of the liner segments  209  as well as the bolt holes  327  of the liner lock key. Alternatively, retaining rods, such as disclosed in co-assigned U.S. Pat. Nos. 5,638,890, 5,638,887, and 4,502,808 (all of which are incorporated herein by reference) could be used in place of the liner lock key  325 . 
     As can be appreciated, the segments of the present invention will cooperate with each other to prevent a segment from separating from the lining when a pin wears or breaks. Although the segment may be somewhat loose, the mill  1  will still be operable, at least for a short period of time, before the segment must be replaced. This will allow for a normal shut down of the machine, rather than an emergency shut down of the machine which would be needed if the segment did separate from the lining. The pin will provide a smooth and continuous transition between the plates, so that the castings and sand see only continuous substantially uninterrupted inner and outer surfaces for the lining  5  and continuous substantially uninterrupted vane along the liner outer surface. 
     As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. For example, the liner segment  209  could be modified such that the flanges on one side of the segment include posts extending axially therefrom, and the flanges on the opposite side of the segments include the holes sized to receive the posts. Thus, the posts of one segment would be received in the flanges holes of the adjacent segment, eliminating the need for separate bolts. This example is merely illustrative.