Patent Publication Number: US-2015078873-A1

Title: Mining Shovel Roller Saddle Block

Description:
TECHNICAL FIELD 
     This disclosure addresses reduction, and expedited repair, of the damage which can result when a mining shovel&#39;s dipper handle “greenhorn” protrusions collide with the shovel&#39;s saddle blocks. 
     BACKGROUND 
     One common type of mining shovel (e.g. the model 4100XPC shovel available from P&amp;H Mining Equipment Inc. of Milwaukee, Wis.) has a boom supported between a pair of saddle blocks. A pair of dipper handles extend longitudinally adjacent to and on either side of the boom. A gear rack on the bottom of each dipper handle engages a pinion mounted on a shaft that extends through the saddle blocks. The mining shovel&#39;s bucket is mounted at the forward end of the dipper handles. The shovel operator actuates a mechanism which drives the dipper handles forwardly or rearwardly, relative to the saddle blocks. 
     So-called “greenhorn” protrusions are provided on the opposed ends of each dipper handle gear rack. The greenhorns protrude outwardly from the dipper handles and act as stops to limit longitudinal movement of the dipper handles relative to the saddle blocks. However, a novice (i.e. “greenhorn”) operator may actuate the dipper handles too quickly, causing the greenhorns to collide at speed with and damage the saddle blocks. The consequential repair operation can cost about $50,000 per saddle block—not including the significant cost implications of lost operation of the mining shovel during the downtime required to make the necessary repairs. 
     Heavy open gear lube oil (“OGL”) is automatically dispensed onto the dipper handles to lubricate them in the vicinity of the saddle blocks. Each year, approximately sixty-five 5-gallon pails of OGL oil are required to lubricate a typical mining shovel in the vicinity of the saddle blocks. This presents an environmental concern because the oil gradually runs off the mining shovel onto the ground. The OGL run off problem is exacerbated during extreme cold weather. 
     This disclosure addresses the foregoing problems. 
     The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive. 
         FIG. 1  is a front sectional view of a mining shovel boom, depicting a leftward (as viewed in  FIG. 1 ) roller saddle block structure atop the shovel&#39;s leftward dipper handle and a rightward (as viewed in  FIG. 1 ) roller saddle block structure atop the shovel&#39;s rightward dipper handle. 
         FIG. 2  is a top view of the  FIG. 1  apparatus. 
         FIG. 3  is a right side view of the apparatus depicted in  FIGS. 1 and 2 . 
         FIG. 4  is a left side view of the leftward roller saddle block structure. 
         FIG. 5  is a front sectional view of the forward portion of the leftward roller saddle block structure. 
         FIG. 6  is a right side view of the leftward roller saddle block structure. 
         FIGS. 7A ,  7 B and  7 C are respectively top, side and front views of a block clamp portion of a roller saddle block structure. 
         FIGS. 8A and 8B  are respectively front and side views of the roller portion of a roller saddle block structure;  FIG. 8C  being an enlarged view depicting the encircled portion of  FIG. 8A . 
         FIGS. 9A and 9B  are respectively front and side views of a roller shaft rotatably mountable within the roller depicted in  FIGS. 8A-8C . 
         FIGS. 10A and 10B  are respectively front and side views of a pair of bushings for rotatably mounting the roller shaft depicted in  FIGS. 9A-9B  within the roller depicted in  FIGS. 8A-8C . 
         FIGS. 11A and 11B  are respectively front and side views of a roller end cap for the roller shaft depicted in  FIGS. 9A-9B ;  FIG. 11C  being an enlarged view depicting the encircled portion of  FIG. 11B ; and  FIG. 11D  being a further enlarged view depicting the encircled portion of  FIG. 11C . 
         FIGS. 12A and 12B  are respectively front and side views of a shaft thrust plate for the roller shaft depicted in  FIGS. 9A-9B . 
         FIGS. 13A and 13B  are respectively front and side views of a roller thrust plate for the roller shaft depicted in  FIGS. 9A-9B . 
         FIG. 14  is a front view of a shim for the block clamp depicted in  FIGS. 7A-7C . 
     
    
    
     DESCRIPTION 
     Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense. 
       FIGS. 1-3  show mining shovel boom  10  supported between left and right roller saddle blocks  12 ,  14 . Left and right dipper handles  16 ,  18  extend longitudinally adjacent to and on either side of boom  10 . Left and right gear racks  20 ,  22  on the bottom of dipper handles  16 ,  18  respectively engage left and right pinions  24 ,  26  respectively. Pinions  24 ,  26  are mounted on a shipper shaft (not shown) which extends through roller saddle blocks  12 ,  14 . The mining shovel&#39;s bucket (not shown) is mounted at the forward end of dipper handles  16 ,  18 . The shovel operator actuates a mechanism (not shown) to drive dipper handles  16 ,  18  forwardly or rearwardly relative to roller saddle blocks  12 ,  14 . Mining shovel boom  10 ; dipper handles  16 ,  18 ; gear racks  20 ,  22 ; and pinions  24 ,  26  are standard components of a prior art mining shovel. Roller saddle blocks  12 ,  14  have been modified in comparison to conventional saddle blocks by removing portions which conventionally overhang dipper handles  16 ,  18  respectively. 
     Pairs of outwardly flanged rollers  28 ,  30  and  32 ,  34  are rotatably mounted above dipper handles  16 ,  18  respectively. Specifically, roller  28  is mounted on roller shaft  36  which is rotatably mounted within block clamps  38 ,  40 ; roller  30  is mounted on roller shaft  42  which is rotatably mounted within block clamps  44 ,  46 ; roller  32  is mounted on roller shaft  48  which is rotatably mounted within block clamps  50 ,  52 ; and roller  34  is mounted on roller shaft  54  which is rotatably mounted within block clamps  56 ,  58 . 
     Each one of block clamps  38 ,  40 ,  44  and  46  has a lower portion which is bolted to shelf  60 , as best seen in  FIGS. 4 ,  5 ,  6 ,  7 A,  7 B and  7 C. Each one of block clamps  38 ,  40 ,  44  and  46  also has an upper portion which is bolted to the corresponding lower portion of the block clamp. Similarly, each one of block clamps  50 ,  52 ,  56  and  58  has a lower portion which is bolted to shelf  62 , as shown in  FIGS. 1 ,  2  and  3 . Each one of block clamps  50 ,  52 ,  56  and  58  also has an upper portion which is bolted to the corresponding lower portion of the block clamp. The undersides of shelves  60 ,  62  are welded atop roller saddle blocks  12 ,  14  respectively. 
     Drop stop  64  is welded atop shelf  60  between block clamps  38 ,  40  and  44 ,  46 . As best seen in  FIG. 2 , drop stop  64  extends transversely across shelf  60  and protrudes above dipper handle  16 , between rollers  28 ,  30 . Similarly, drop stop  66  is welded atop shelf  62  between block clamps  50 ,  52  and  56 ,  58 . As best seen in  FIG. 2 , drop stop  66  extends transversely across shelf  62  and protrudes above dipper handle  18 , between rollers  32 ,  34 . 
     Lifting eyes  68 ,  70 ,  72 ,  74 ,  76 ,  78 ,  80 ,  82  are mounted atop the upper portions of block clamps  38 ,  40 ,  44 ,  46 ,  50 ,  52 ,  56  and  58  respectively. As shown in  FIG. 4 , shackles  69 ,  73  are coupled to lifting eyes  68 ,  72  respectively. Cable  85  extends through aperture  84  in drop stop  64 . One end of cable  85  is coupled to shackle  69 . The opposite end of cable  85  is coupled to shackle  73 . A second cable (not shown) is similarly coupled through aperture  86  in drop stop  64  between lifting eyes  70 ,  74 . A third cable (not shown) is similarly coupled through an aperture in drop stop  66  between lifting eyes  76 ,  80 ; and a fourth cable (not shown) is similarly coupled through another aperture in drop stop  66  between lifting eyes  78 ,  82 . 
       FIGS. 8A and 8B  depict roller  30  in isolation. An optional lubricant injection passage  88  can be formed in roller  30 . Cap  90  is threadably fastened over the injection port end of passage  88  and can be temporarily removed for injection of lubricant into passage  88 . Lubricant injected into passage  88  flows through passage  88  to lubricate shaft  42  relative to bushings  92 ,  94 . Instead of (or in addition to) forming passage  88  in roller  30  as shown, another lubricant injection passage (not shown) may be formed in shaft  42 . Rollers  28 ,  32  and  34  are identical to roller  30 . Rollers  28 ,  30 ,  32 ,  34  may be formed of an ultra heavy duty, hardened, material such as SAE grade 4140 steel or T-1™ steel. The surfaces of rollers  28 ,  30  and  32 ,  34  which contact dipper handles  16 ,  18  do not require lubrication, thus eliminating the aforementioned OGL environmental problem. 
       FIGS. 9A and 9B  depict roller shaft  42  in isolation. Roller shaft  42  is rotatably supported within roller  30  by bushings  92 ,  94  ( FIGS. 10A ,  10 B) which are fitted into the opposed ends  96 ,  98  of aperture  100  which extends longitudinally through roller  30 . Roller shafts  36 ,  48 ,  54  are identically rotatably supported within rollers  28 ,  32 ,  34  respectively. 
     Roller end cap  104  (best seen in  FIGS. 11A and 11B ) is bolted over the inward end of roller  30  (as seen in  FIG. 2 ). Identical roller end caps  102 ,  106 ,  108  are bolted over the inward ends of rollers  28 ,  32 ,  34  respectively. Roller end caps  102 ,  104 ,  106 ,  108  cover the inward ends of shafts  36 ,  42 ,  48 ,  54  respectively. O-ring  110  ( FIG. 11D ) is fitted within circumferential groove  112  formed in flange  114  of roller end cap  104  to assist in retaining lubricant within roller  42 . Similar O-rings (not shown) are provided in the flanges of end caps  102 ,  106 ,  108  respectively. 
     Shaft thrust plate  116  (best seen in  FIGS. 12A and 12B ) is bolted onto the inward end of shaft  42  as seen in  FIG. 5 . Identical shaft thrust plates (not shown) are bolted onto the inward ends of shafts  36 ,  48 ,  54  respectively. 
     Roller thrust plate  122  (seen in  FIGS. 1 ,  2 ,  5   13 A and  13 B) is fastened (e.g. by shrink fitting) around shaft  42 , adjacent outward flanged rim  128  of roller  30 . A mechanical seal is coupled between roller thrust plate  122  and rim  128  to assist in retaining lubricant within roller  30 . Identical roller thrust plates  118 ,  124 ,  126  are similarly fastened and sealed around shafts  36 ,  48 ,  54  adjacent outward flanged rims  120 ,  130 ,  132  of rollers  28 ,  32 ,  34  respectively as seen in  FIGS. 1 and 2 . 
       FIG. 14  depicts shim  134  which is sized and shaped for slidable insertion between any of block clamps  38 ,  40 ,  44 ,  46  and shelf  60 ; or between any of block clamps  50 ,  52 ,  56 ,  58  and shelf  62 . A plurality of similarly shaped shims, each having a different thickness dimension, can be inserted (i.e. stacked) between the respective block clamps and shelves, as shown in  FIGS. 1-6 ,  7 B and  7 C. 
     In operation, rollers  28 ,  32  and  30 ,  34  roll atop dipper handles  16 ,  18  respectively as the shovel operator controls forward or rearward travel of the dipper handles. The rollers&#39; outward flanged rims  120 ,  128 ,  130 ,  132  respectively contact the dipper handles&#39; outward sides (i.e. the left side of dipper handle  16  and the right side of dipper handle  18  as viewed in  FIGS. 1 and 2 ) to maintain alignment of the rollers atop the dipper handles. If a novice (i.e. “greenhorn”) operator actuates dipper handles  16 ,  18  too quickly, the greenhorn protrusions (not shown) on the opposed ends of each dipper handle may collide at speed with rollers  28 ,  32  or  30 ,  34  (depending on the dipper handles&#39; direction of travel). Such collision applies an upwardly directed force to the underside of rollers  28 ,  32  or  30 ,  34 . The collision force is transmitted through the roller shafts and block clamps, and may break bolts  136  which fasten the block clamps to shelves  60 ,  62  respectively. If bolts  136  break, then the roller saddle block structure (i.e. the roller, roller shaft and block clamps) would ordinarily fall away from the mining shovel, potentially damaging other portions of the mining shovel and/or nearby equipment; and/or potentially injuring nearby personnel. However, drop stops  64 ,  66  (to which the block clamps are cabled and shackled as aforesaid) prevent the roller saddle block structure from falling away from the mining shovel. For example, with reference to  FIGS. 1 ,  2 ,  4  and  5 ; if all of bolts  136  associated with either or both of the roller saddle block structures formed by rollers  28 ,  30 , roller shafts  36 ,  42 , and block clamps  38 ,  40 ,  44 ,  46  break; then either or both of those roller saddle block structures may become separated from shelf  60 . However, cables (e.g. cable  85 ) are shackled at both ends to the respective roller saddle block structures and are retained by passage of the cables through drop stop  64 , thus preventing either roller saddle block structure from falling away from the mining shovel. 
     It is relatively simple to use a crane to remove a damaged roller saddle block structure and to manouevre a replacement structure into position to replace the damaged structure. The damaged structure can be transported to a shop for repair (e.g. replacement of broken bolts, or repairing possible damage to the rollers). 
     Conventional saddle blocks require periodic maintenance to accommodate normal wear. During such maintenance operations, the conventional saddle block&#39;s overhang structure (i.e. the saddle block portion which conventionally overhangs the dipper handles) is unbolted and removed with the aid of a crane, shims are inserted (or removed) to offset accumulated wear, and the overhang structure is then replaced and bolted back down atop the shims. In contrast, a plurality of shims  134 , each having a different thickness, are pre-installed (i.e. stacked) between each block clamp and the shelf to which the block clamp is bolted, as seen in  FIGS. 1-6 ,  7 B and  7 C. In order to accommodate wear of rollers  28 ,  30 ,  32 ,  34  a workman need only loosen bolts  136 , slidably remove an appropriate one of pre-installed shims  134 , then re-tighten bolts  136 . No crane is required to perform this shim adjustment operation. 
     While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. For example, roller saddle block structures can be fabricated and installed at the factory during construction of a new mining shovel. Alternatively, a mining shovel&#39;s conventional saddle blocks which have been damaged as aforesaid can be reconfigured as roller saddle block structures as explained above. 
     As another example, instead of extending a single cable through a drop stop and shackling the cable&#39;s opposed ends to roller saddle block structures on opposite sides of the drop stop, one could provide two cables. One end of each cable could be connected to the drop stop and the opposed end of each cable could be connected to one of the roller saddle block structures. 
     It is intended that the scope of the claims should not be limited by the embodiments set forth above, but should be given the broadest interpretation consistent with the description as a whole. 
     DRAWING REFERENCE NUMERALS 
     
         
           10  mining shovel boom 
           12  saddle block 
           14  saddle block 
           16  dipper handle 
           18  dipper handle 
           20  gear rack 
           22  gear rack 
           24  pinion 
           26  pinion 
           28  roller 
           30  roller 
           32  roller 
           34  roller 
           36  roller shaft 
           38  block clamp 
           40  block clamp 
           42  roller shaft 
           44  block clamp 
           46  block clamp 
           48  roller shaft 
           50  block clamp 
           52  block clamp 
           54  roller shaft 
           56  block clamp 
           58  block clamp 
           60  shelf 
           62  shelf 
           64  drop stop 
           66  drop stop 
           68  lifting eye 
           69  shackle 
           70  lifting eye 
           72  lifting eye 
           73  shackle 
           74  lifting eye 
           76  lifting eye 
           78  lifting eye 
           80  lifting eye 
           82  lifting eye 
           84  aperture 
           85  cable 
           86  aperture 
           88  lubricant injection passage (in roller  28 ) 
           90  cap 
           92  bushing 
           94  bushing 
           96  open end of aperture  100   
           98  opposed open end of aperture  100   
           100  longitudinal aperture (in roller  28 ) 
           102  roller end cap 
           104  roller end cap 
           106  roller end cap 
           108  roller end cap 
           110  O-ring 
           112  circumferential groove (in flange  114 ) 
           114  flange (of roller end cap  102 ) 
           116  shaft thrust plate 
           118  roller thrust plate 
           120  flanged rim (of roller  28 ) 
           122  roller thrust plate 
           124  roller thrust plate 
           126  roller thrust plate 
           128  flanged rim (of roller  30 ) 
           130  flanged rim (of roller  32 ) 
           132  flanged rim (of roller  34 ) 
           134  shim 
           136  bolt 
           138  bolt 
         
           140 
         
         
           142 
         
         
           144