Abstract:
A device for removing obstructions from a work site. The device is attachable to the front of a work machine. The device comprises a frame, a flange, a rotatable cutting member supported on the flange, and a motor that rotates the cutting member. The flange is non-rotatable, but is movable along at least one length relative to the frame. The motor may be supported on the flange. The device further comprises a plurality of removably attachable blocking members for decreasing the range of travel of debris generated during operation of the cutting member. The rotatable cutting member is movable about three axes relative to the flange such that changes in conditions or temperatures do not cause the cutting member to break.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. patent application Ser. No. 11/465,737 filed on Aug. 18, 2006, entitled BALANCING ASSEMBLY FOR ROTATING CYLINDRICAL STRUCTURES, which was a continuation of U.S. patent application Ser. No. 10/717,114 filed on Nov. 19, 2003 entitled BALANCING ASSEMBLY FOR ROTATING CYLINDRICAL STRUCTURES, now U.S. Pat. No. 7,104,510 which claims priority from U.S. Provisional Patent Application Ser. No. 60/427,915 filed on Nov. 20, 2002 entitled BALANCING ASSEMBLY FOR ROTATING CYLINDRICAL STRUCTURES. 
    
    
     REFERENCE TO MICROFICHE APPENDIX 
     This application is not referenced in any microfiche appendix. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to balancing assemblies for rotating members for use in removing obstructions from a work site. More particularly, the invention relates to self-aligning balancing assemblies for large cylindrical cutting members supported on a work vehicle. 
     2. Background 
     Industry is replete with many examples of large cylindrical drums that must be rotated for various reasons. For example, factories in the paper industry must employ large heavy drum assemblies for receiving and storing rolls of kraft paper. The road construction industry uses road machines having large drums with cutting blades embedded on the drum surface for abrading rock during road construction. 
     These cylindrical drum assemblies are generally massive and require a high torque motor or engine to initiate rotation of the drum and to maintain rotation during operation. Although the drum assemblies are rotated at a low number of revolutions per minute (rpm), the high mass of the drum results in several problems. First, the centrifugal force produced by the rotation of a high mass structure is extreme even at low rpm and necessitates a robust, heavy duty gear box to transmit the rotational force of the motor to the drum. Often, a separate gear box and motor assembly is used on each of the opposing ends of the axis about which the drum rotates. In such a configuration, one gear box and motor assembly is structured for clockwise rotation and the opposing gear box and motor assembly is structured for counter-clockwise rotation so that their rotational force combines to rotate the drum in a single direction. These gear box and motor assemblies distribute the force required to rotate the drum so that less robust gear boxes and motors may be used. 
     Second, if the drum is unbalanced around the axis of rotation so as to produce an oscillating radial force, this radial force will excessively wear the gear box and motor so as to cause premature failure. When using a pair of opposing gear box and motor assemblies, the alignment of the centerline of both assemblies reduces radial forces and resultant wear on the bearings of these assemblies; otherwise the misalignment will cause premature failure of the bearings. This alignment may be achieved by precise machining and balancing of the drum. However, such machining and balancing for drums with diameters in excess of 12 inches and lengths in excess of five feet requires large, heavy duty, and expensive machines to turn the massive drums and cut away excess metal. High precision is difficult to attain when dealing with such heavy, bulky structures. Additionally, the removal, shipping, and replacement of the drum in its installed location is expensive in terms of required man power. The removal, shipping, and replacement can also be further complicated by the fact that machines employing such heavy drums, e.g. road equipment, are often used in remote locations where transportation is difficult and knowledgeable maintenance personnel are unavailable. 
     Third, during use, the drum is loaded by the work against which it rotates, e.g. the road surface for a cutting drum or the uneven winding of paper on a takeup drum in a paper plant. This loading coupled with the massiveness of the drum causes a small amount of deflection which also results in unbalancing of the drum assembly. 
     Fourth, even if the drum is perfectly balanced about its axis of rotation, the gear box must be positioned precisely so that the shaft is exactly colinear with the axis of rotation. This requires that the mounting surfaces for the gear box must be machined to very precise tolerances. On a large machine, this is very difficult and expensive, and, while it improves the initial misalignment, it does not help with the deflection problem. 
     As can be seen, there is a need for a method and apparatus to maintain the balance of a massive rotating drum assembly, reduce the requirement for close precision in the physical balancing process for the drum, and dynamically adjust for in-use deflection of the drum so that balance about the axis of rotation is maintained. 
     SUMMARY OF THE INVENTION 
     One aspect of the present invention is directed to a device for removing obstructions from a worksite. The device comprises a frame, a flange, a first motive force means, and a rotatable cutting member. The flange is supported on the frame and moveable about three axes. The first motive force means is supported by the flange. The cutting member is operatively connected to the motive force means such that the motive force means is disposed within the rotatable cutting member. 
     In another aspect of the invention, the device for removing obstructions from a work site comprises a frame, a rotatable cutting drum, a means for rotating the cutting drum, and a means for aligning a centerline of the rotatable cutting drum. The means for rotating the drum is supported by the frame. The means for aligning a centerline of the rotatable cutting drum is supported by the means for rotating the rotatable cutting drum and allows movement of the cutting drum along at least one length. 
     Yet another aspect of the invention is directed to a work machine. The work machine comprises a drive frame, a means for translating the drive frame, and a device for removing obstructions from a worksite supported by the drive frame. The device comprises a frame, a flange, a first motive force means, and a rotatable cutting member. The flange is supported on the frame and moveable about three axes. The first motive force means is supported by the flange. The rotatable cutting member is operatively connected to the first motive force means such that the first motive force means is disposed within the rotatable cutting member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a device for removing obstructions from a worksite comprising a rotating cutting member and motive force means axially positioned at either or both ends of the cutting member. 
         FIG. 2  is a perspective view of an end plate of the device shown in  FIG. 1  with a protective panel removed to show the well into which the drum is inserted and supported; 
         FIG. 3A  is a plane view of an end plate for use with the present invention; 
         FIG. 3B  is a sectional view taken from  FIG. 3A  showing of the support housing within which the drum is inserted and its relationship with the end plate; 
         FIG. 3C  shows the end panel with bolt holes; 
         FIG. 4A  is a plane view of the support housing shown previously in  FIGS. 3A and 153B ; 
         FIG. 4B  is a sectional view of the support housing shown in  FIG. 4A  showing placement of the slots therein; 
         FIG. 5  is a longitudinal sectional view of the cutting assembly of  FIG. 1 ; 
         FIG. 6  is a longitudinal sectional view of the cutting assembly of  FIG. 1 ; 
         FIG. 7  is a cut-away sectional view of the components of a self-aligning flange for use with the cutting assembly of the present invention; 
         FIG. 8A  is a side view of the self-aligning flange; 
         FIG. 8B  is a side view of the self-aligning flange taken from  FIG. 8A ; 
         FIG. 9  is a top view of an elongate member comprising a plurality of lateral shafts; and 
         FIG. 10  is a side view of a work machine adapted for use with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following detailed description shows the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made for the purpose of illustrating the general principles of the invention and the best mode for practicing the invention, since the scope of the invention is best defined by the appended claims. The invention is capable of other embodiments and of being practiced or carried out in a variety of ways. It is to be understood that the phraseology and terminology employed herein are for the purpose of description and not of limitation. 
     Referring to  FIG. 1 , a device  10  for removing obstructions from a worksite is shown. The device  10  is used for grinding rock and hard earth for the preparation of road beds and for removing obstructions, such as brush and trees, from a worksite. With reference to  FIG. 10 , the device is configured for mounting on a tractor or other work machine  15 , the tractor comprising a drive frame, also referred to as undercarriage,  16 , a means for translating the undercarriage  17 , and an arm  18  connecting to the device  10  at the connection points  11 ,  12 , and  13  ( FIG. 1 ). In a preferred embodiment, the device comprises a separate engine  19  for operation of the device  10 , mounted to the rear of the work machine  15 . One skilled in the art may appreciate that the means for translating the undercarriage  17  may also power the device  10  eliminating the need for the separate engine  19 . Alternatively, the device  10  may be integrated into the work machine  15  or connected by other mechanisms known to one skilled in the art. The means for translating the undercarriage  17  comprises a powered motor (not shown) and may comprise powered tires, tracks, or a combination of tires and tracks. As shown, in  FIG. 10 , the work machine  15  comprises tires. The motor (not shown) may be hydraulic or electric and powered by a combustion engine, a hydraulic motor, an electric source or other power source. The tires or tracks may be powered by individual motors or a single motor. If tires are utilized, the work vehicle  15  may be steered through skid steering technique, or with turning wheels. 
     Turning again to  FIG. 1 , the device  10  comprises frame  20  and a rotatable cutting member  30 , or drum, which is supported on the frame at both ends of the cutting member. A gear box  110  and motor  100  are located at one and/or both ends of the cutting member  30  and are covered by a protective panel  40  attached to an end plate  50 . The surface of the cutting member  30  supports cutting blades or teeth (not shown) for removing obstructions or undesired materials as the drum rotates. 
     The device  10  comprises a plurality of skid shoes  55  located on the frame  20 . The skid shoes  55  provide a surface of contact between the ground and the device  10 . Preferably, the skid shoes  55  may be adapted such that a distance between a centerline  220  ( FIG. 6 ) of the cutting member  30  and the ground may be manipulated by an orientation of the skid shoes. More preferably, the orientation of the skid shoes  55  may be manipulated by the arms of the work vehicle or through other mechanical or hydraulic manipulation. Alternatively, the skid shoes  55  may be moveable relative to the cutting member through the use of hydraulic cylinder or mechanical means located on the frame  20 . Further, a plurality of bolts could be disconnected and the skid shoes  55  repositioned to adjust the distance between the centerline  220  of the cutting member  30  and the ground. 
     Referring now to  FIG. 2 , the end plate  50  of the device  10  is shown with the protective panel  40  removed to expose the circular hole  33  in which cutting member  30  is supported. 
     Referring now to  FIGS. 3A ,  3 B and  3 C, the end plate  50  is shown and comprises a support housing  60  within which the cutting member  30  rotates and circular hole  33 . The circular hole  33  is sized such that a flange  200  ( FIG. 7 ) and motive force means  100  ( FIG. 7 ) may be supported within the support housing  60 . The support housing  60  defines a plurality of gaps  270  which will be described with more particularity below. Alternatively, the support housing may comprise a plurality of protrusions (not shown) which engage gaps in a flange as discussed in an alternative embodiment below. As shown in  FIG. 3C , the end plate  50  may define a plurality of bolt holes  51  which provide connection points between the frame  20  and the skid shoes  55  as described in  FIG. 1 . 
     Referring now to  FIGS. 4A and 4B , shown therein is the support housing  60 . As shown, the support housing  60  comprises four (4) of the gaps  270  equally spaced about the support housing. Alternatively, a different number of gaps  270  or spacings thereof may be utilized, as long as those gaps correspond to the features of the flange as will be described below. 
     It should be noted that contact operation of the device  10  may cause the teeth to become deflected or broken. Deflected or broken teeth may call slight deviations in the weight of the cutting member  30 . Even slight deviations in the weight of the cutting member  30  may cause it to become slightly unbalanced. Additionally, extreme cold weather may cause internal components of the cutting member  30  to expand due to heat caused by rotation of the cutting member, while the frame may contract due to external temperatures. As shown in  FIG. 7 , a self-aligning flange  200  is introduced to solve these and other problems. 
     Turning now to  FIG. 7 , a sectional view of the device  10  is shown. The device  10  comprises the frame  20 , the cutting member  30 , a means for rotating the cutting member  60 , and a means for aligning the centerline  220  of the cutting member  30  while allowing movement of the cutting member along at least one length. 
     The frame  20  provides support for other elements of the device  10  and comprises the support member  60  as described above. The support member  60  is constrained to contain the means for aligning the centerline  220 . This means, as shown in  FIG. 7 , comprises a self-aligning flange  200 . The flange  200  is non-rotatably supported within the support member  60  by radially extending retaining members or protrusions  260  adapted to mate with the gaps  270  in the support housing  60 . The flange  200  may comprise a rim  201  that is a sectional ellipsoid or sphere. The protrusions  260  are sized within the gaps  270  such that the flange  200  is moveable about three axes relative to the support housing  60 , limited only by the tolerance of the gaps  270  relative to the protrusions  260 . The protrusions  260  are sufficiently sized such that rotational forces due to operation of the first motive force means  100  and the rotational cutting member  30  are fully transferred to the frame  20 , while allowing the flange  200  some tolerance of motion about at least one axis. Preferably, some tolerance of motion is allowed about at least three axes. 
     The means for rotating the cutting member  30  comprises a motive force means  100 . The motive force means  100  may comprise a motor and gear box  110 . Alternatively, the motive force means comprises hydraulic or other components adapted to provide a rotational force to the cutting member  30 . The motive force means  100  may be powered by a dedicated combustion engine or power may be provided externally from components of the work machine. The motive force means  100  provides power which is transferred to rotational motion by the gear box  110 . As shown, the motive force means  100  is suspended within the support housing and the gear box is attached to an inner surface of the rotating cutting member  30  at an internal drum  31 . Alternatively, a belt or chain system may be utilized to provide rotational motion to the rotating cutting member  30 . 
     Turning now to  FIG. 5 , a cross-section of the device  10  is shown. As shown, the device  10  further comprises a second flange  201 , a second motive force means  101  comprising a second gear box  111  at a second end  35  of the cutting member  30 . The flange  200  and second flange  201  may be substantially identical at each end of the cutting member  30 . At each end of the cutting member  30  the gear box  110  and second gear box  111  are fixedly bolted to an internal drum  31  within each end of cutting member  30  so that the centerline  225  ( FIG. 6 ) of each gear box  110 ,  111  is substantially aligned with the centerline  220  ( FIG. 6 ) of the rotating cutting member. 
     One skilled in the art will appreciate the device  10  may comprise only one motive force means  100  at a first end of the cutting member  30 . In this embodiment, the second flange  201  located at a second end  35  of the cutting member  30  would comprise a bearing such that the second end of the cutting member would rotate freely relative to the second flange, while allowing the second flange to move about a plurality of axes relative to the support housing  60  as discussed above with reference to  FIG. 7 . 
     The first motive force means  100  is adapted to operate with sufficient horsepower to rotate the cutting member  30  at an operational rate. For example, the motive force means may provide an operational rate of thirty-five horsepower in an application utilizing light equipment. Alternatively, heavy-duty applications of the present invention may require an operational rate of five hundred forty horsepower. The gear box  110  is adapted to rotate the cutting member  30  at a rotational velocity between 10 and 1500 rpm. Preferably, the cutting member  30  has a rotational velocity between 300 and 800 rpm. The preferred rotational velocity of the cutting member  30  provided by the motive force means  100 ,  101  for clearing brush and trees is 500 rpm. However, other speeds may be advantageous for other applications of the device  10 , such as the breaking of rock or permafrost, and thus other speeds of the cuffing member  30  are anticipated. 
     With reference to  FIGS. 5A and 3B , shown therein is a cross section of the flange  200 . As shown, the flange  200  comprises a number of axial bolt holes  250 . Each of the to projections  260  are inserted into the holes  250  such that they extend beyond the rim  210  of the flange  200  and engage the support housing  60  at gaps  270  ( FIG. 7 ). Alternatively, projections from the support housing  60  may extend into the bolt holes  250 . 
     Turning now to  FIG. 9 , shown therein is a debris blocking device supportable on the frame  20  and adapted to decrease the range of travel of debris generated during operation of the cutting member  30 . The debris blocking device comprises an elongate member  300  comprising a plurality of lateral shafts  310 , each lateral shaft  310  terminating in a knob  320 . The elongate member  300  is adapted to be fixed to the work vehicle with a substantially horizontal orientation. The knob  320  is defined by a width that is substantially greater than its corresponding lateral shaft  310 . Each lateral shaft is adapted to support a means for settling debris, or debris blocking member  330 . As shown in  FIG. 9 , the blocking members  330  may comprise a length of chain hanging from each lateral shaft  310 . Each of the chains  330  may be looped over one of the plurality of knobs  320  and suspended from one of the plurality of lateral shafts  310 . The lateral shafts  310  are preferably positioned such that each chain  330  is suspended freely and extends substantially from the elongate member  300  to the ground. The looping, instead of bolting or welding, of the chains  330  to the lateral shafts  310  allows cheap, efficient replacement when one or more of the plurality of chains is broken or lost during operation of the device  10 . 
     The plurality of blocking members  330  are positioned such that they provide a means for knocking down spoils, or brush that has been displaced by the operation of the cutting member  30 . The plurality of blocking members  30  may be positioned proximate the device  10 , or at any other location on the work vehicle where the settling of spoils is desired. Preferably, the elongate member  300  is positioned to the rear of the cutting member  30  and attached to the frame  20  (shown in  FIG. 1  without the chains  330 ). Alternatively, the blocking members  330  may comprise iron rods, polymer or metal flaps, or other instruments to settle spoils. The blocking members  330  may be placed on one or both sides of the elongate member  300 . 
     As has been demonstrated, the present invention provides an advantageous apparatus and method for maintaining alignment and balance of a massive rotating cylindrical drum within close tolerances. While the preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims shall be construed to include both the preferred embodiment and all such variations and modifications as fall within the spirit and scope of the invention.