Abstract:
In a chain excavator including an excavation chain with links routed around a drive sprocket and an end idler with a base plate mounted to a link for supporting excavation implements, a stabilizing element extends rearwardly from directly behind the excavation implement in order to contact and be supported by its trailing base plate.

Description:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0001]    Not Applicable  
         FIELD OF THE INVENTION  
         [0002]    The present invention relates to a mounting arrangement for mounting a cylindrical cutting element to a chain to provide support necessary for cutting difficult materials such as rock formations, and road surfaces.  
         BACKGROUND OF THE INVENTION  
         [0003]    Cylindrical cutting elements are often mounted to a variety of driven elements to perform excavations of various difficult type of ground, including compacted sands, clay, gravel and rock. The driven elements include drums and chains. FIGS. 1-4 illustrate a prior art trencher  100  with a typical roller chain assembly  10 . FIG. 1 illustrates the trencher  100  with a boom  102  in a raised position, and a lowered position. In the lowered position, the boom  102  forces the roller chain assembly  10  into engagement with the ground. The chain is powered by a drive sprocket, not shown, such that end idler  104  will rotate clockwise, and the bottom strand of the roller chain assembly  10  will move from right to left. When in engagment with the ground the chain assembly  10  will excavate and transport cuttings to a discharge conveyor  106 , thus forming a trench as the trencher  100  moves from right to left. FIG. 2 illustrates a typical roller chain assembly  10  comprising attachment links  12 , side links  14 , and rollers  16 .The chain assembly  10  further comprises base plates  18 , conical cutters  20 , tool holders  22  and back bend bars  24 , as illustrated in FIGS. 3 and 4. FIG. 3 illustrates a double chain assembly where the base plates are each attached to 2 chains. The conical cutters  20  are positioned on the base plates at an angle such that they contact the ground at the required orientation. The chain assembly  10  will move from left to right as illustrated in FIG. 4, with the conical cutter  20  contacting the ground. This contact will generate an excavation force F 1  on the tip of the conical cutter  20 A. Conical cutter  20 A is mounted to baseplate  18 A which is mounted to attachment links  12 A. The force F 1  will generate a moment, substantially around axis  13 . The chain assembly  10  will flex until backbend bars  24 A contact side links  14 A. In this manner the back bend bars  24  stiffen the chain assembly  10 .  
           [0004]    When utilized in extreme conditions this type of drive and mounting arrangement is has been found to be insufficient. There are times that the tool holders  22  are not sufficiently attached to the base plates and that the overall chain assembly includes sufficient flexibility to induce unwanted vibrations.  
           [0005]    An improved mounting arrangement is needed for application of this type of excavation assmbly in extreme conditions.  
         BRIEF SUMMARY OF THE INVENTION  
         [0006]    According to the present invention there is provided an improved mounting arrangement for a conical cutter to a chain assembly 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    [0007]FIG. 1 is a side plan view of a prior art trencher with a boom in  2  positions with a prior art chain assembly;  
         [0008]    [0008]FIG. 2 is an isometric view of a prior art roller chain;  
         [0009]    [0009]FIG. 3 is a top view of a prior art chain assembly;  
         [0010]    [0010]FIG. 4 is a side view of a prior art chain assembly;  
         [0011]    [0011]FIG. 5 is a top view of the chain assembly of the present invention;  
         [0012]    [0012]FIG. 6 is a side view of the chain assembly of the present invention;  
         [0013]    [0013]FIG. 7 is a side view of a boom assembly utilizing a chain assembly of the present invention;  
         [0014]    [0014]FIG. 8 is a side plan view of a trencher including a chain boom and excavating drums; and  
         [0015]    [0015]FIG. 9 is a side view of an excavating drum configured according to the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]    Referring now to the drawings, like reference numerals designate identical or corresponding parts throughout the several views. The included drawings reflect the current preferred embodiment. There are many additional embodiments that may utilize the present invention. The drawings are not meant to include all such possible embodiments.  
         [0017]    [0017]FIGS. 5 and 6 illustrate the tool holder  22  supported on a bottom plate  30  and a support gusset  32 . Support gusset  32  is attached on a first end to bottom plate  30  and on its opposite end to the tool holder  22 . Bottom plate  30  is secured to the base plate  34 A and also supported by contact with base plate  34 B, when in the configuration illustrated in FIG. 6. In this manner the resulting chain assembly provides improved stiffness, and a more robust mounting arrangement for tool holder  22 . The bottom plate  30  and the support gusset  32  can be made in one piece or several pieces connected together. Even the tool holder  22  for holding tooth  20  can be make in one piece with the bottom plate  30  and the support gusset  32  if desired. The supporting gusset  32  extends from directly behind the cutter or tooth  20 , and it contacts the base plate  32  and not the chain link  14  when forces are applied to the tooth  20  while in operation of the chain trencher.  
         [0018]    The resulting chain is illustrated in an assembly between a drive sprocket  110  and an end idler  112  in FIG. 7. As the chain assembly travels around the drive sprocket  110  and end idler  112  the bottom plate  30  will separate from the trailing base plate such that the extra rigidity resulting from the contact between the bottom plate  30  and its trailing base plate  34 . Gusset  32 , however, provides additional support of the tool holder  22  such that, even in the position where the chain is travelling over the end idler  112 , the connection of the tool holder to the base plate  34  is enhanced.  
         [0019]    Gusset  32  sweeps back in a configuration such that it is always positioned at an effective radius that is less than the effective radius swept out by the point of the conical cutter  20 .  
         [0020]    [0020]FIG. 8 illustrates a trencher  200  with a boom assembly including a center excavating chain  202  and  2  excavating drums  204  as described in pending U.S. patent application Ser. No. 10/227,838 filed Aug. 27, 2002, filed by assignee entitled excavation apparatus, which application is incorporated herein by reference. The excavating chain  202  of trencher  200  is configured to include the gusset  32  and bottom plate  30  supporting tool holder  22 . The tool holders  22  that are attached to the excavating drums are similarly supported by gussets  34 , and bottom plate  36  as illustrated in FIG. 9.  
         [0021]    Obviously many modifications and variations of the present invention are possible in light of the above teachings, including variations in the shape of the knife mount pin and cooperating apertures in the knife adapter. It is known to use various configurations of these components, other than the herein specified cylindrical shapes. These would include conical sections, and could include pins with various cross-sections such as square or hexagonal. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.  
         [0022]    Claims  5 - 8  are duplicative of claims  1 - 4  except for the reference numerals. It is believed that leaving the reference numerals in claims  1 - 4  will help the Examiner examine these all of these claims. Accordingly, applicants will authorize cancellation of claims  1 - 4  after the first Office Action, as well as authorization to cancel this paragraph.