Abstract:
A tree cutting attachment for a skid loader or other types of self-propelled work vehicles to be used at construction and landscaping sites. The device is used to cut down brush and trees of up to 8-10 inches in diameter. The tree cutting attachment is made up of a motor driven rotor assembly which is journaled within the frame of the attachment. The rotor assembly comprises a cage-like mounting system having pockets in which tempered steel blades, approximately 6 inches in width are bolted in a side-by-side relation. Two rows of blades are mounted 180 degrees apart proximate the periphery of a rotor comprised of a series of parallel, generally circular plates that are welded to longitudinally extending rods. The knife blade elements are bolted to the blade holders with the non-sharpened end of the blade elements abutting a flat steel bar that forms part of the cage.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    I. Field of the Invention  
           [0002]    This invention relates generally to a tree cutting machine, and more particularly to a tree cutting machine which serves as an attachment for a skid loader.  
           [0003]    II. Discussion of the Prior Art  
           [0004]    Clearing areas of brush and trees in an efficient and effective manner has long been a challenge to construction and landscaping workers. A machine capable of performing these tasks would be a valuable tool for difficult and challenging development jobs.  
           [0005]    In response to this need, several rotary cutting attachments that could be used on vehicles were devised. One such device is disclosed in U.S. Pat. No. 4,355,670. This device comprises a large diesel truck with a tree felling attachment drum and assembly driven by a hydraulic motor. Its attached cutting assembly has a unique drum construction. The drum&#39;s complex mounting structure, fragmenting elements, cutting means, teeth etc. make this an original invention, vastly different in operation from the present invention. U.S. Pat. No. 5,499,771 is a related design comprising a tree cutting attachment which cuts, clips, and mulches trees with a set of cutting teeth. This varies from the present invention that implements a shaving technique. Another, closely related, prior art design is U.S. Pat. No. 1,312,450. This machine discloses disintegration of a tree stumps using a rotary attachment but operates as a large and complex group of belts, gears, and levers.  
           [0006]    To enable the present invention to be most widely used, it was designed to attach to a skid steer vehicle. Skid steer vehicles are compact, highly maneuverable vehicles which are controlled by an operator seated within the operator compartment by actuating a pair of steering levers. Attachments, such as an auger, grapple, sweeper, landscape rake, snow blower or backhoe, some of which may include a hydraulic motor, are sometimes mounted to a boom assembly on the front of the skid steer loader. An auxiliary hydraulic system is used to control the flow of hydraulic fluid between the skid steer vehicle auxiliary hydraulic pump and the hydraulic motor on the front mounted attachment. This actuates hydraulic cylinders that position the front mounted attachments.  
           [0007]    Various designs have been made with respect to attachments for skid-steer vehicles including those disclosed in U.S. Pat. Nos. 5,666,794 and 4,878,713. These devices mount to a skid-steer vehicle but are designed to be a flail mower and pavement planing machine, respectively, and do not perform needed tree cutting and brush clearing functions.  
           [0008]    Therefore, what is needed is the tree cutting machine of the present invention which effectively allows for easy and efficient tree and brush clearing with an improved rotary cutting design over past inventions.  
         SUMMARY OF THE INVENTION  
         [0009]    The present invention provides for a tree cutting attachment for use with a skid loader or other type of self-propelled work vehicle at construction and landscaping sites. The tree cutting attachment comprises a motor driven rotor assembly journaled within the frame of the attachment. The rotor assembly comprises a cage-like mounting system having a plurality of pockets in which tempered steel blades are bolted in a side-by-side relation. Two rows of blades are mounted 180 degrees apart proximate the periphery of the rotor. The rotor also includes a series of parallel, generally circular plates that are welded to longitudinally extending rods. Located between adjacent ones of the plates are blade holders. The knife blade elements are bolted to the blade holders with the non-sharpened end of the blade abutting a flat steel bar that forms part of the cage. The blade elements are affixed to the blade holders such that a gap between the blades&#39; cutting edges and an elongated shear bar can be set to define a desired depth-of-cut. The shear bar is adjustably affixed to the frame in which the rotor is mounted.  
           [0010]    The invention includes a deflector assembly joined to the frame. It carries a plurality or short lengths of chain across the front of the device. It functions to prevent debris from projecting forward when cutting brush. The present invention also includes a pusher member made up of a framework of bars which cause cut trees to fall forward when they are severed.  
           [0011]    These and other objects, features, and advantages of the present invention will become readily apparent to those skilled in the art through a review of the following detailed description in conjunction with the claims and accompanying drawings in which like numerals in several views refer to the same corresponding parts. 
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0012]    [0012]FIG. 1 is a perspective view of the front and right sides of the tree cutting attachment of the present invention;  
         [0013]    [0013]FIG. 2 is a perspective view of the back and left sides of the tree cutting attachment of the present invention;  
         [0014]    [0014]FIG. 3 is a left side cross-sectional view of the present invention;  
         [0015]    [0015]FIG. 4 is a further cross-sectional view of the present invention taken through the rotor; and  
         [0016]    [0016]FIG. 5 is a perspective view of the rotor assembly employed in the preferred embodiment. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0017]    The present invention represents broadly applicable improvements for tree cutting attachments. The embodiments herein are intended to be taken as representative of those in which the invention may be incorporated and are not intended to be limiting.  
         [0018]    Referring first to FIG. 1, there is shown a perspective view of the front and left sides of the tree cutting attachment for a skid loader or other type of self-propelled work vehicle. The assembly itself is indicated generally by numeral  10 . It includes a housing or shroud  12 , left side panel  14 , right side panel  16 , pulley cover  18 , rotor assembly  20 , chain deflector  22 , and pusher member  24 .  
         [0019]    With reference to FIG. 2, the tree cutting attachment is seen in a perspective view of the rear and left sides. The housing or shroud  12  shown is basically a piece of sheet metal bent into, roughly, a wedge-like shape, open on the front and bottom sides. On the rear side of the housing is the skid loader quick-attachment mount  26 . The skid loader mount  26  pivotally mounts to the lift arms of a skid loader, as is well known in the art. Those skilled in the art will recognize that other types of quick attach mounts can be used to couple the tree/brush cutter to work vehicles other than skid loaders.  
         [0020]    On the sides of shroud  12  are left end panel  14 , and right end panel  16 . These are four-sided pieces of sheet metal with rounded corners. These panels contain several holes around their perimeters for attachment to the shroud  12 , as well as a large hole  28  near the bottom center of the panels containing bearings  29  for journaling the rotor assembly. (See FIG. 1.) Both left and right panels  14  and  16  have a U-shaped metal skid  30  protruding in a perpendicular direction from side surface at a lower edge thereof The left panel has a triangular-shaped cover  18  placed over it. This cover shields the elements contained beneath it. Mounted on the panel  16  is a shield bracket  32 , which juts out and around the bearings  29  and the rotor shaft  34  journaled therein.  
         [0021]    Also shown in FIG. 2 is pusher member  24 . Pusher member  24  is a safety structure, which is designed to push against the trunk of a tree as it is being cut and prevents it from falling onto the cab of the skid vehicle. The pusher member  24  has two pairs of legs pivotally mounted to left and right panels  14  and  16 . The front most two legs  36  are rigid, L-shaped members. A crossbar  44  of the pusher member  24  extends between the rearmost two legs  38  which are straight, metal bars, preferably of square-shape cross section. There are several holes  40  in the lower end of the bars  38  allowing adjustment of the angle at which the pusher projects from the cutting assembly. The top ends of the rearmost legs  38  are pivotally engaged with small linking pieces  42 . These linking pieces attach near the ends of pusher member bar  44  as best seen in FIG. 2.  
         [0022]    [0022]FIG. 3 is a left side view of the tree cutting attachment, as seen when the pulley cover  18  is removed from left side panel  14  to expose the internal components. The internal components are the parts which transfer power to the rotor cutting assembly  20 . More specifically, a drive pulley  50  is located near the top of left side panel  14 . It is mounted on the shaft of a hydraulic motor (not shown) bolted to the opposite side of the panel  14 . The hydraulic motor  51  is driven from a hydraulic pump (not shown) coupled to the power take off of the self-propelled work vehicle to which the tree/brush cutting is being connected. The drive pulley  50  rotates a belt  52  wrapped around the cutter shaft pulley  54 . The cutter shaft pulley  54  is located directly below drive pulley  50  near the bottom of left side panel  14 . Drive pulley  50  when driven by the hydraulic motor places a large torque upon rotor shaft  34  to which the drive pulley  54  is keyed. The torque driven rotor shaft  34  causes the rotor assembly  20  with its cutting knives to be rotated in the frame. The rotor assembly  20  will be discussed in greater detail below.  
         [0023]    The belt  52  transfers power from the hydraulic motor to the rotor assembly and is made of a cord reinforced elastomeric material. It is tightly engaged against the two pulleys  50  and  54  because of a tensioning pulley  56 . This pulley  56  acts as a belt tightener and prevents belt slippage that would adversely affect the amount of torque placed upon drive pulley  54 . The belt tensioning pulley  56  pivotally attaches to a bracket  58  which then pivotally mounts to another link segment  60 . The link segment  60  is attached to a tube and threaded rod tightening component  62 . The bolt on component  62  can be adjusted to either tighten or loosen the belt engagement around the pulleys.  
         [0024]    Referring now to FIG. 4, another cross-section of the tree cutting attachment is shown. The backside of the quick-attachment mount  26  is adapted to engage with the arms of a skid loader vehicle. The rotor assembly  20  is journaled for rotation in bearings  29  set n the side plates  14  and  16 . This assembly is made up of a generally cylindrical framework of metal bars, spacer plates and knives. At the center of this framework is the rotor shaft  34 . Surrounding the shaft is a series of disc-like spacer plates  64 , held in parallel relation by four metal bars, equally spaced around the disc perimeter and to which the spacer plates  64  are welded. Two of the metal bars  65  and  66  are of a circular cross-section and rod-like, and two of the bars  67  and  68  have a rectangular cross-section. The circular rods  65  and  66  are located opposite one another and help to provide stability and rigidity to the assembly. The rectangular bars  67  and  68  also provide stability and additionally form back-up plates for the knife blades  70  that are mounted diametrically around the periphery of the assembly. Trees and brush enter the rotor assembly from the left in FIG. 4 and then are shaved down to small pieces by the spinning action of the cutting blades. The rotor assembly will be discussed further with the aid of FIG. 5. Positioned adjacent the perimeter of the rotor assembly is a adjustable shear bar  72 . This adjustable shear bar  72  acts as an anvil controls the depth of cut and the size of the wood chips produced as the rotor assembly is driven. The distance between the tips of the rotating knives  70  and the tip of shear bar  72  govern the chip size, which can be varied by setting the adjustable shear bar  72 . A bolt  74  passes through a slotted aperture in the angle bracket  77 . Setting the shear bar  72  to a minimum knife clearance reduces feed rate, particle size, and horsepower required. Setting the shear bar  72  to the maximum knife clearance increases the feed rate, particle size and horsepower required.  
         [0025]    In FIG. 4, trees and brush enter the assembly from the left side and are shaved down as they move to the right. The panel projecting out from the front of the assembly serves as a brush deflector  76  to the shaved chips. A plurality of short, closely-spaced, individual lengths of chain  78  hang down in a line from the brush deflector  76 . The brush deflector  76  and the hanging chains  78  serve to stop chips from projecting out of the device at high velocity when it is in operation.  
         [0026]    [0026]FIG. 5 is a detail view of the rotor assembly  20  of the present invention removed from its housing  12 . The rotor components are mounted and rotate with driven rotor shaft  34 . As mentioned, this driven shaft is journaled by bearings affixed to side plates  14  and  16 . Along the length of the shaft is a plurality of regularly spaced disc components  64 . These disk components are axially spaced on the shaft  34  and provide the assembly with a caged, generally cylinder-like shape. Around the periphery of these discs are the four rods  65 ,  66 ,  67 ,  68  holding the discs  64  in place, as discussed earlier with reference to FIG. 4. Extending tangentially from the periphery of the discs  64  are knife blades  70 . The knife blades  70  comprise short, generally rectangular metal plates of tool steel only a few inches in width. They are bolted on diametrically opposite sides of the rotor assembly so as to provide proper balance. These blades are placed in the pockets in between the discs  64  such that the non-cutting end of the blades abut up against the rectangular bar shaped rods  67  or  68 . Because of the structural rigidity of the blades mounted in pockets and abutting against the rectangular rods, severe impact forces seen by the knife mounting bolts  73  are absorbed, reducing the chance of shearing of the retaining bolts.  
         [0027]    Another important feature of the tree cutting attachment of the present invention includes the way that the leading edge of angle bar  77  keeps uncut material from being propelled up and forward, away from the knives. Maintaining contact with the knives helps to continue the feed of new wood material to the knives. The flat, back side of the “L” shaped angle bar  77  helps control overfeeding caused by uncut material being pulled in at an uncontrolled rate as in the case of the tapered or wedge shaped chamber present in prior art designs, thereby reducing horsepower requirements.  
         [0028]    Both the rectangular bar shaped rods  67  and  68  and the cylindrical rods  65  and  66  mount in the two circular end plates  82  and  83 . There is a grouping of holes  84  around the outside perimeter of these circular end plates for attachment of balancing weights if required to inhibit vibration of the cutter rotor assembly. The center holes  86  of the end plates  82  and  83  enable the rotor shaft  34  to extend through the end plates.  
         [0029]    The operation of the tree cutting attachment for a skid loader is as follows. First, the tree cutting attachment is mounted to a skid loader utilizing the conventional skid loader mount  26 . The operator of the skid loader turns on the hydraulic motor  51  coupled to the work vehicle&#39;s hydraulic pump causing the drive pulley to rotate. A belt transfers power from the drive pulley  50  to the shaft pulley  54  and, in turn, rotates the rotor assembly  20  with its knives  70  in the direction opposite that of ground travel at about 1700 rpm. Because the rotor  20  is made to rotate in a direction so that its bottom is moving in a direction opposite to the ground travel of the skid loader, the rotating blades tend to lift the downed tree from the ground, facilitating the shreading action.  
         [0030]    When the tree cutting attachment is lowered and is driven into brush, the brush deflector  76  is adjusted by tilting the arms of the skid loader to a position where the structure and chains are able to deflect stones and other debris downward. When the material comes into contact with the brush, it is lifted upward and cut by the rotating knives. The cut residue is then discharged over the top of the rotor and out the back of the assembly.  
         [0031]    When cutting down a tress, the operator elevates the arms of the skid loader to lift the attachment  10  to a desired height. As the rotor  20  is driven, the two rows of blades  70  shave through the trunk of the tree as the pusher  24  applies a force to the tree trunk above the level it is being cut so as to cause it to fall forward as the trunk is ultimately shoved to the breaking point. Once felled, the operator may operate the skid loader so as to run the rotor mounted blades back and forth over the trunk until it is reduced to chips or shavings which more readily decompose.  
         [0032]    This invention has been defined herein in considerable detail in order to comply with the Patent Statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use such specialized components as are required. However, it is to be understood that the invention can be carried out by specifically different equipment and devices, and that various modifications, both as to the equipment details and operating procedures, can be accomplished without departing from the scope of the invention itself For example, rather than driving the rotor  20  with a hydraulic motor, it may also be mechanically coupled directly to a power take off of the self-propelled work vehicle to which the tree/brush cutter is connected.