Abstract:
A single arm support apparatus for a rockwheel for excavating a trench through difficult materials, including rock. The rock cutting attachment includes a frame assembly which supports a cutting wheel in a manner that permits it to be inserted into the ground to approximately the radius of the wheel. The cutting wheel mounts to a shaft that is supported by bearings on a single side of the wheel, and is rotationally driven by a hydraulic motor. Additional structure mounted on the frame provides depth control.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
         [0001]    Not applicable.  
         STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0002]    Not applicable.  
         REFERENCE TO MICROFICHE APPENDIX  
         [0003]    Not applicable.  
         BACKGROUND OF THE INVENTION  
         [0004]    1. Field of the Invention  
           [0005]    The present invention relates generally to excavation machines. Specifically, the present invention relates to a single arm support apparatus for a rockwheel.  
           [0006]    2. Description of Related Art  
           [0007]    As can be seen by reference to the following U.S. Pat. Nos. 2,420,836; 4,553,522; 4,762,371; 5,203,615; and 5,657,803, the prior art is replete with myriad and diverse single arm support apparatus for a rockwheel.  
           [0008]    While all of the aforementioned prior art constructions are more than adequate for the basic purpose and function for which they have been specifically designed, they are uniformly deficient with respect to their failure to provide a simple, efficient and practical single arm support apparatus for a rockwheel.  
           [0009]    As a consequence of the foregoing situation, there has existed a longstanding need for a new and improved single arm support apparatus for a rockwheel, and the provision of such a construction is a stated objective of the present invention.  
         BRIEF SUMMARY OF THE INVENTION  
         [0010]    The present invention relates to a single arm support apparatus for a rockwheel which is utilized to excavate material and form an open trench, typically in soil conditions ranging from hard compacted abrasive soils, to loose soils with a significant percentage of stones, to solid stone or concrete. This trench is formed by hard, cutting teeth mounted on the outer circumference of a relatively thin disc/wheel that is rotated with sufficient torque to propel the teeth through the material being cut. At the same time it is forced down into engagement with the ground so that the lowest portion of the wheel defines the bottom of the trench. The wheel is propelled along the ground surface to extend formation of the trench the desired length and profile.  
           [0011]    The desired trench is typically being formed to allow installation of water lines, gas lines, or electrical lines of various types and thus the width of the trench is typically much less than the desired depth of the trench. The maximum depth is typically approximately equal to the radius of the wheel.  
           [0012]    The critical capabilities of the apparatus include:  
           [0013]    1. ability to set and maintain the desired trench depth;  
           [0014]    2. ability to achieve sufficient torque and speed to excavate at an acceptable rate; and  
           [0015]    3. ability to withstand the substantial loads inherent to the application of inserting a relatively thin wheel into the ground forming a trench in hard compacted soil or rock.  
           [0016]    Machines providing these capabilities have been available for several years. Machines of this sort manufactured and sold by Vermeer Mfg. Co. typically comprise a prime mover of various sorts, including track mounted or rubber tired vehicles equipped with what is known as a rock cutter or rock wheel attachment. They have been marketed by Vermeer as RW6540, RW4147, RW5536, RW6540, RW7548, RW8536, RW8540, RW8554, RW855. The attachment is comprised of:  
           [0017]    1. a welded frame designed to couple to the prime mover and support rotary mounts for the wheel on both sides;  
           [0018]    2. one rotary mount typically being a hydraulic motor or gearbox;  
           [0019]    3. the other rotary mount being a bearing;  
           [0020]    4. the wheel with cutting teeth;  
           [0021]    5. a shaft or rotary support member passing from one rotary support to the next;  
           [0022]    6. shielding to direct the cuttings and shield moving components;  
           [0023]    7. hydraulic system to raise and lower the attachment; and  
           [0024]    8. stabilizers on both the left and right side to control the lowered position of the attachment to allow control of the depth of the trench.  
           [0025]    The significant forces inherent in this application have always required a design as this including support on both sides of the wheel. There are inherent difficulties associated with these attachments related to this need to support the wheel on both sides including:  
           [0026]    1. difficulties in manufacturing the frame in a manner to assure proper alignment of the rotary mounts for the wheel;  
           [0027]    2. difficulties in assembling the wheels to the frame associated with the rotary mounts on both sides; and  
           [0028]    3. difficulties in maintenance if the wheel needs to be removed, in that at least one rotary mount needs to be removed.  
           [0029]    The mounting of rotating discs/wheels has been accomplished in a variety of manners. Examples of various mounts can be seen in U.S. Pat. No. 2,420,836 to Nelson; U.S. Pat. No. 4,553,622 to De Cortanze; U.S. Pat. No. 5,657,803 to Kappel; U.S. Pat. No. 4,762,371 to Lupton; and U.S. Pat. No. 4,230,372 to Marten.  
           [0030]    In the patent to Nelson a thin disc, saw blade, is mounted to a shaft that is supported on bearings on a single side of the disc. This application includes high rotational speed of the disc and relatively low forces being applied to the cutting disc, forces required for proper function of the saw blade.  
           [0031]    The patent to DeCortanze discloses a driving wheel for a motorcycle is mounted on a shaft again supported on bearings on a single side of the wheel. Here again the application includes relatively high rotational speeds and relatively low forces as the force is limited by the coefficient of friction between the tire and the road surface.  
           [0032]    The patent to Kappel discloses a cutting wheel of a stump cutter that is mounted on a shaft of a gearbox again supported by the bearings of the gearbox on a single side of the wheel. This application involves relatively high speeds, with a relatively small outer diameter wheel.  
           [0033]    The patent to Lupton discloses a cutting wheel, a road planar, that is mounted on a shaft that is supported on both sides of the wheel. This application subjects the frame to forces required to cut pavement with cutting teeth mounted on the circumference of a wheel. This design will have similar difficulties as described as inherent with the rock wheel attachments.  
           [0034]    The patent to Marten discloses a pair of excavating wheels mounted to a single shaft and utilized to excavate in a manner similar to the present invention.  
         SUMMARY OF THE INVENTION  
         [0035]    The present invention relates generally to a trencher having a prime mover and a rock cutting attachment for excavating a trench through difficult materials including rock. The rock cutting attachment includes a frame assembly which supports a cutting wheel in a manner that permits it to be inserted into the ground to approximately the radius of the wheel. The cutting wheel mounts to a shaft that is supported by bearings on a single side of the wheel, and is rotationally driven by a hydraulic motor. Additional structure mounted on the frame provides depth control.  
           [0036]    An object of the present invention is to provide a mounting arrangement for an excavating wheel that provides for simplified components in order to reduce manufacturing complexity.  
           [0037]    A further object of the present invention is to provide a mounting arrangement for an excavating wheel that provides for simplified assembly of the wheel to its support structure.  
           [0038]    A still further object of the present invention is to provide a mounting arrangement for an excavating wheel that provides for simplified maintenance.  
           [0039]    Other objects, advantages, and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0040]    [0040]FIG. 1 is a left side perspective view of a preferred embodiment of the excavating wheel attachment mounted onto a prime mover;  
         [0041]    [0041]FIG. 2 is a left side perspective view of the same embodiment of the excavating wheel shown in FIG. 1 with some of the shielding removed;  
         [0042]    [0042]FIG. 3 is a right side perspective view of the same embodiment of the excavating wheel shown in FIG. 1 with some of the shielding removed;  
         [0043]    [0043]FIG. 4 is a perspective view of the main frame assembly;  
         [0044]    [0044]FIG. 5 is a perspective view of the wheel support shaft assembly;  
         [0045]    [0045]FIG. 6 is a perspective breakdown of the components of the wheel support shaft assembly;  
         [0046]    [0046]FIG. 7 is a side elevational view of the lift assembly;  
         [0047]    [0047]FIG. 8 is a perspective view of the stabilizer assembly;  
         [0048]    [0048]FIG. 9 is a perspective view of the excavating wheel assembly with portions thereof exploded away; and  
         [0049]    [0049]FIG. 10 is a perspective view of the motor mounting. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0050]    Referring to the drawings, wherein like reference numerals designate identical or similar parts throughout the views, FIG. 1 shows a prime mover  10  and a preferred embodiment of the excavating wheel attachment  100 . The prime mover  10  typically comprises an engine and drive line capable of propelling the assembly along the ground surface to transport between excavations and to propel the excavating wheel through the ground to extend the trench. The embodiment illustrated utilizes rubber tires for ground engagement. Tracks are also commonly used for ground engagement. The prime mover also typically includes a hydraulic system that is capable of providing power to a motor on the excavating wheel attachment  100  to rotate the wheel and of providing controlled pressure circuits to raise and position the excavating wheel attachment  100 .  
         [0051]    The excavating wheel attachment  100  typically attaches to the prime mover  10  at a mounting plate. Hydraulic lines transfer the hydraulic fluid from the circuits on the prime mover  10  to the appropriate components of the excavating wheel attachment  100 .  
         [0052]    Referring now to FIGS. 2 and 3, a preferred embodiment of the excavating wheel attachment  100  is illustrated. The attachment is comprised of a mounting plate  110 , main frame assembly  130 , lift assembly  170 , stabilizer assembly  180 , excavating wheel assembly  200  and drive motor  240 .  
         [0053]    The mounting plate  110  (FIG. 2) includes a surface  112  that mates with the prime mover. Fasteners  114  secure the attachment to the prime mover  10 . Main frame pivot supports  118  and lift cylinder pivot support  120  are fixedly attached to the opposite side  116  of plate  110 . Securing means cooperate with these pivot supports  118 , in the preferred embodiment pivot pins  122  secure the main frame assembly  130  to the mounting plate  110  and a pivot pin  124  secures a lift cylinder  172  to the mounting plate  110 .  
         [0054]    Referring now to FIG. 4, the main frame assembly  130  is illustrated. The main frame assembly  130  is comprised of a main frame  132  and a wheel support shaft assembly  150 .  
         [0055]    The main frame  132  includes a pivot axis  134  on a first distal end  136  defined in this embodiment by a through-hole  138 . A wheel mount plate  142  is at the opposite end of the main frame  132 . A stabilizer support pivot  144  is defined in this embodiment by aligned holes in stabilizer mounting tabs  140  and main structural member  141 . The main frame  132  further includes shielding structure  148  (shown in dashed lines in FIGS. 2, 3 and  4 ) which is adapted to cooperate with the excavating wheel.  
         [0056]    The wheel support shaft assembly  150  is secured to the wheel mount plate  142  of the main frame  132  by fasteners  146 .  
         [0057]    Referring now to FIGS. 5 and 6, the wheel support shaft assembly  150  is illustrated. This assembly is comprised of housing  152 , wheel mount shaft  154 , wheel bearing assemblies  156 , dust seal  157 , oil seal  153 , bearing clamp nut  159 , and o-ring seal  158 . Wheel mount shaft  154  is supported by the two wheel bearing assemblies  156  while bearing clamp nut  159  restrains those components in the housing  152 . Mating surface  162  of the housing  152  mates to the wheel mount plate  142  of the main structural member  140  shown in FIG. 4 and the two are connected with fasteners  146 .  
         [0058]    Referring now to FIG. 7, the lift assembly  170  is illustrated. This assembly is comprised of a lift cylinder  172 , cylinder pin  124  and cylinder pin  174 . The cylinder  172  is attached at a first end to the mounting plate  110  at the lift cylinder pivot support  120  with cylinder pin  124  and at the opposite end to the main structural member  141  with cylinder pin  174  through an opening in member  141   a . Hydraulic hose  176  is connected to the cylinder  172  and at the other end to a hydraulic system that is part of the prime mover  10 .  
         [0059]    Referring now to FIG. 8 the stabilizer assembly  180  is illustrated. This assembly is mounted onto the main frame  132  (FIG. 2) and is comprised of stabilizer arm mount pins  182 , stabilizer arms  184 , cylinders  186 , stabilizer cylinder mount pins  188  and hydraulic hoses  190 . The stabilizer arms are secured to the main frame  132  by the mount pins  182  in a manner such that they can rotate between a lowered position where the foot  194  (see FIGS. 2 and 8) will limit the depth of penetration of the excavating wheel to the minimum controlled depth and an upper position where the foot  194  will limit the depth of penetration to the maximum controlled depth, which is slightly less than the radius of the excavating wheel. Cylinders  186  are connected to mounting tabs  140  on one end and to the stabilizer arms  184  on the other end with pins  188 . Extension or retraction of these cylinders controls the position of the stabilizer arms and thus the depth of the excavation. Hoses  190  transfer hydraulic oil with controlled flow and pressure from the prime mover  10 .  
         [0060]    Referring now to FIG. 9 the excavating wheel assembly  200  is illustrated. This assembly  200  is comprised of the wheel  210  and cutter assemblies  220 . The cutter assemblies  220  consist of pockets  222  and teeth  224 . The cutter assemblies  220  are secured to the wheel  210  with fasteners  226  that engage with the pattern of holes  216  in the wheel  210 . Assembly  200  is attached to hub  154  by fasteners  230  into threaded holes  164  as shown in FIGS. 3 and 9.  
         [0061]    The wheel  210  includes an axis of rotation  212  that is defined by the center of pilot hole  214 . A pattern of holes  216  on the outer circumference of the wheel  210  needs to be concentric with the pilot hole  214  for proper performance. A second pattern of holes  218  is arranged in a bolt pattern such that they are also concentric with the pilot hole  214  and designed to mate with the pattern of holes  164  in the wheel mount shaft  154  (FIG. 6). Fasteners  230  (FIG. 9) secure the excavating wheel assembly  200  to the wheel mount shaft  154 .  
         [0062]    The wheel mount shaft  154  is supported in the housing  152  as shown in FIG.6. The wheel  210  is secured on one end as shown in FIG. 9. The opposite end of the wheel shaft  154  includes an internal spline connection  155  shown in FIG. 10. As seen in FIG. 10 a drive motor  240  includes an externally splined shaft  232  that engages with the internal spline  155  of the wheel mount shaft  154 . The drive motor  240  is secured to the housing  152  by fasteners  234  thus engaging the mating splines and enabling the drive motor  240  to control rotation of the wheel assembly  200 .  
         [0063]    Referring again to FIG. 2, the operation of the attachment is described. Hydraulic fluid is provided to the drive motor  240  from the prime mover  10 , typically with the main frame assembly  130  pivoted into its raised position by lift assembly  170  (FIGS. 2 and 7). This will cause the wheel assembly  200  to rotate. As it is rotating, it is lowered into engagement with the ground  12  which results in formation of the trench. Wheel assembly  200  continues to progress into the ground  12  until the shoe  194  of the stabilizer assembly  180  contacts the ground  12 , thus controlling the depth of the trench. The prime mover  10  is now propelled forward (to the left as shown in FIG. 2) thus moving the excavating wheel attachment  100  parallel to the ground  12  extending the length of the trench.  
         [0064]    Advantages of this invention include the fact that the support for the excavating wheel assembly  200  comes solely from the wheel support shaft assembly  150 , located on a single side of the wheel. The wheel support shaft assembly  150  is of a size and shape that it can be easily manufactured within close dimensional tolerances. Since the support is provided with this single component the main frame  132  is also much easier to manufacture as there are no critical alignment features related to supports for the excavating wheel assembly on both sides. An additional advantage is apparent when the excavating wheel assembly  200  is installed as it need to mate up to the wheel mount shaft  154  only.  
         [0065]    Accordingly, it will be appreciated that the preferred embodiment shown herein accomplishes all of the aforementioned objects. Obviously many modifications and variations of the present invention are possible in view of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.