Abstract:
An improved self-aligning tree delimbing apparatus for use in conjunction with a knuckle boom loader having an inner frame member pivotally mounted and concentrically received within an outer frame member, which is rigidly attached to a base member. Pivotally mounted within the inner frame member is a tree delimbing cutter head assembly having opposing pairs of tree guide arms and tree delimbing arms pivotally mounted thereon, thereby allowing for simultaneous multi-dimensional pivotal motion of the cutter head assembly within the frame members. Such motion allows the cutter head assembly to easily align with the longitudinal axis of the trees being delimbed, thereby increasing the efficiency of the apparatus while reducing the binding stresses and necessary force applied by the knuckle boom loader.

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to an improved tree delimbing apparatus for use in the forestry industry. More particularly, the present invention relates to an improved delimbing apparatus for use in conjunction with a knuckle boom loader. With even greater particularity, the present invention relates to an improved delimbing apparatus utilizing a cutter head assembly capable of self-alignment with the longitudinal axis of the trees being delimbed. With even greater particularity, the present invention relates to an improved self-aligning tree delimbing apparatus capable of removing limbs from a felled tree as a result of bidirectional longitudinal motion imparted to the felled tree by the knuckle boom loader. 
     BACKGROUND OF THE INVENTION 
     Tree delimbing devices are generally known in the forestry and tree harvesting industry. Although various delimber configurations are present in the industry, the most common configuration includes a longitudinal delimbing assembly having a plurality of guide arms encircling a felled tree as it passes through the apparatus. The unwanted limbs of the felled tree are removed by a plurality of stripping arms attached to the apparatus upon longitudinal movement of the tree through the apparatus. Felled trees are generally placed in the delimbing assembly with a mechanical knuckle boom loader or the like, the guide arms and stripping arms are pivotally positioned proximate the felled tree, and the tree is longitudinally moved through the delimbing apparatus by the knuckle boom loader. This longitudinal movement causes the felled tree to engage the stripping arms, thereby shearing the limbs from the felled tree trunk. However, the industry has found that this particular apparatus configuration is prone to gouging the trunks of the felled trees to be delimbed as a result of improper alignment of the felled tree trunks with the axis of the longitudinal delimbing assembly. As a result of this gouging, the usable board foot of the trunk is lessened, thereby decreasing the efficiency and profitability of a timber harvesting operation utilizing such an apparatus. Further, increased stresses are generated and greater horsepower is required to pull the tree through the apparatus, thereby increasing the mechanical fatigue of the apparatus. 
     In response to this problem, U.S. Pat. No. 4,899,794 to Hamby illustrates a TREE DELIMBING DEVICE WITH SELF ALIGNING CUTTER HEAD, which is designed with the intention of minimizing gouging of trunks. The apparatus embodied in the Hamby patent generally utilizes a substantially rectangular lower base plate having an upper base plate mounted thereto via a swivel and roller assembly for rotational motion of the upper base plate about the swivel via the roller. A yoke member having a cutter head assembly rotatably mounted between substantially vertical yoke arm members is affixed to the upper base plate, such that said yoke rotates with said upper base plate. Thus, it is taught that the vertical axis of rotation provided by the swivel, along with the horizontal axis of rotation provided by the yoke, allows for self-alignment of the cutter head assembly with the longitudinal axis of the felled tree, thereby eliminating gouging of the trunks of the trees. However, the configuration of the Hamby apparatus has nonetheless been found to cause gouging of the trunks as a result of improper cutter head alignment, as well as being prone to binding and breakage as a result of improper and unequal loading of the points of rotation of the apparatus used to longitudinally align the cutter head. Further, the use of the swivel and roller combination has been found susceptible to poor operation as a result of unwanted material obstructing operation of the roller, which further facilitates overloading of the remaining pivot points as well as binding of the device. Therefore, there is a need in the timber and forestry industry for an improved self-aligning felled tree delimbing apparatus capable of efficiently delimbing trees without gouging the trunks, critically binding the apparatus, or overloading the pivot points of the apparatus. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an improved self-aligning felled tree delimbing apparatus for use in conjunction with a knuckle boom loader. It is a further object of the present invention to provide an improved self-aligning felled tree delimbing apparatus for use in conjunction with a knuckle boom loader capable of self-aligning a delimbing cutter head assembly with the longitudinal axis of a felled tree placed within the apparatus. It is a further object of the present invention to provide an improved self-aligning felled tree delimbing apparatus for use in conjunction with a knuckle boom loader capable of delimbing trees without gouging the trunks. It is yet a further object of the present invention to provide an improved self-aligning felled tree delimbing apparatus for use in conjunction with a knuckle boom loader capable of efficiently delimbing felled trees without binding the operation of the apparatus. It is a further object of the present invention to provide an improved self-aligning felled tree delimbing apparatus for use in conjunction with a knuckle boom loader capable of effectively distributing the pivot point load forces applied to the apparatus as a result of self-alignment of the cutter head assembly with the longitudinal axis of the felled tree. It is yet a further object of the present invention to provide an improved self aligning delimbing apparatus capable of delimbing felled trees as a result of bidirectional longitudinal motion of the felled trees within the delimbing apparatus. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A device/apparatus embodying the features of the present invention is depicted in the accompanying drawings, which form a portion of this disclosure, wherein: 
     FIG. 1 is a perspective view of the apparatus mounted on a transportable frame member; 
     FIG. 2 is a simplified perspective view of the apparatus with the cutter head active components removed; 
     FIG. 3 is a simplified front elevational view of the apparatus with the cutter head active components removed; 
     FIG. 4 is a full front elevational view of the apparatus; 
     FIG. 5 is a side elevational view of the apparatus as seen from the right side of FIG. 4; 
     FIG. 6 is a top plan view of the apparatus; 
     FIG. 7 is a perspective view of the cutter head assembly; 
     FIG. 8 is a rear elevational view of the cutter head assembly; 
     FIG. 9 is a front elevational view of the cutter head assembly 
     FIG. 10 is a side elevational view of the cutter head assembly; 
     FIG. 11 is a top plan view of the cutter head assembly; 
     FIG. 12 is a perspective view of the cutter bar and guide arm assemblies; 
     FIG. 13 is a front elevational view of an upper pivotal mounting assembly; and 
     FIG. 14 is a perspective view of the cutter bar and guide arm assemblies with the interconnecting mechanical gears. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings for a better understanding of the principles of operation and structure of the invention, it will be seen that FIG. 1 generally shows a perspective view of the improved self-aligning apparatus  100  for delimbing felled trees attached to a transportable frame member  102 . A rotatable knuckle boom loader  104 , which is typically mounted to transportable frame member  102  proximate delimbing apparatus  100 , operates to position felled trees  108  within delimbing apparatus  100  via an arm  110 , which carries grapple  106 . Knuckle boom loader  104  additionally serves to pull felled trees  108  longitudinally through delimbing apparatus  100 , thereby allowing for the removal of unwanted limbs from the felled tree trunk by delimbing apparatus  100 . Upon removal of the unwanted limbs from the felled tree trunk, delimbing apparatus  100  cuts the trunk to the desired longitudinal length via pivotally mounted driven topping saw  176 . 
     More particularly, self-aligning delimbing apparatus  100 , as shown in FIGS. 1,  2 , and  3 , comprises a cutter head assembly  112  mounted within a gimbal type frame assembly  114 . Gimbal type frame assembly  114  operates to permit cutter head assembly  112  to incline freely in any direction within a particular range of motion, thereby allowing for self alignment of cutter head assembly  112  with the longitudinal axis of the trees placed within apparatus  100  for delimbing. In the preferred embodiment illustrated herein, gimbal type frame assembly  114  includes a substantially horizontal base frame member  116  rigidly mounted to transportable frame member  102 . A generally semicircular outer frame member  118  of substantially tubular cross section having an upper and lower terminating ends  122  and  124  is rigidly mounted to horizontal base frame member  116  in a substantially vertical orientation, as best shown in FIGS. 3 and 5. Outer frame structural support members  120 , which are rigidly attached to horizontal base frame member  116  and outer frame member  118 , maintain and support the substantially vertical orientation of outer frame member  118  during operation of apparatus  100 . 
     Concentrically received within outer frame member  118  is arcuate inner frame member  126 , also of substantially tubular cross section, which forms the remaining portion of gimbal type frame member  114 . Inner frame member  126  includes a first  128  and second  130  terminating ends forming an opening  132  therebetween, as shown in FIGS. 3 and 4. Inner frame member  126  is concentrically received within outer frame member  118 , such that first terminating end  128  of inner frame member  126  is coterminous with upper terminating end  122  of outer frame member  118 . Additionally, first terminating end  128  of inner frame member  126  is pivotally secured to upper terminating end  122  of outer frame member  118  at a first location via a first pivotal mounting assembly  134 , which will be further discussed herein. A second pivotal mounting assembly  136  pivotally secures inner frame member  126  to outer frame member  118  at a second location. The second location lies upon an axis  138  coincident with a first diameter of outer frame member  118 , which is located on the plane forming a 45° angle with horizontal base frame member  116 . The combination of first pivotal mounting assembly  134  and second pivotal mounting assembly  136  allows for pivotal rotation of inner frame member  126  within outer frame member  118  about first axis  138 . 
     Completing the major components of delimbing apparatus  100  is cutter head assembly  112 , which is pivotally mounted within inner frame member  126  about a second axis  140  perpendicular to first axis  138  and passing through the center of outer frame member  118 , as shown in FIGS. 3 and 4. Thus, second axis  140  lies in a plane forming a 45° angle with horizontal base frame member  116 , and generally bisects the open semi-circular portion of outer frame member  118  between upper terminating end  122  and lower terminating end  124 . The first of two pivotal mounting points for cutter head assembly  112 , designated upper pivotal mounting assembly  142 , is located proximate second terminating end  130  of inner frame member  126  along second axis  140 , as shown in FIGS. 3 and 4. Upper pivotal mounting assembly  142  pivotally connects the upper portion  143  of cutter head assembly  112  to second terminating end  130  of inner frame member  126 . The second of two pivotal mounting points for cutter head assembly  112 , designated lower pivotal mounting assembly  144 , is positioned on the lower portion  145  of cutter head assembly  112 . Lower pivotal mounting assembly  144  pivotally connects lower portion  145  of cutter head assembly  112  to inner frame member  126  at a location along second axis  140  corresponding generally to the bisection point  147  of the closed portion  149  of outer frame member  118 . The combination of first pivotal mounting assembly  142  and second pivotal mounting assembly  144  allows for pivotal rotation of cutter head assembly  112  within inner frame member  126  about second axis  140 . Therefore, the combination of pivotal rotation about first axis  138  and second axis  140  allows for pivotal movement of cutter head assembly  112  in any direction without binding the apparatus. However, the pivotal motion of apparatus  100  is limited by stop  146 , which is rigidly attached to the horizontal base frame member  116  immediately below the rear portion  152  of the cutter head assembly  112 . Thus, stop  146  serves to limit the pivotal rotation of cutter head assembly  112 , which will be further discussed herein. The four pivotal mounting assemblies  134 ,  136 ,  142 , and  144  used to pivotally secure the moving components of gimbal type frame assembly  114  are generally shown in FIG.  13 . The pivotal mounting assemblies typically comprise a load supporting bearing assembly  135  rotatably engaged with a load alignment shaft  137 , as is generally known in the art. The incorporation of this particular bearing  135  and shaft  137  arrangement allows for pivotal movement about the longitudinal axis of shaft  137 . 
     The operational components of cutter head assembly  112  include an elongated cutter head frame member  148  forming a longitudinal channel  150  having a first and second substantially vertical elongated channel walls  153 ,  155 . The front portion  152  of longitudinal channel  150  includes a rotatably mounted guide wheel  156  attached thereto for rotatably supporting felled trees  108  placed within longitudinal channel  150 , as shown in FIGS. 6 and 10. A pair of spatially positioned opposing limb stripping members  158  are pivotally mounted proximate the rear portion  154  of longitudinal channel  150 , as shown in FIGS. 10 and 11. First stripping member  159  is pivotally mounted to extend from first wall  153  of longitudinal channel  150 , while second stripping member  161  is pivotally mounted to extend from second wall  155  of longitudinal channel  150 . Positioned immediately below first and second stripping members  159  and  161  is stationary stripping member  180 , which is rigidly attached to cutter head frame member  148  proximate the rear portion  154  of channel  150 . Stripping members  159 ,  161  are caused to concomitantly pivot between a first open position distal each other, and a second closed position proximate each other, via a first shaft and gear arrangement  170  in engagement with a first selectively actuated hydraulic actuator  162 , as shown in FIG.  14 . In the closed position, stripping members  159 ,  161 , in conjunction with stationary stripping member  180 , completely encircle felled trees  108  within longitudinal channel  150 , thereby allowing for shearing of limbs from felled trees  108  from all sides. 
     A pair of spatially positioned opposing limb guide arm members  110  are pivotally mounted proximate the front portion  152  of longitudinal channel  150 , as shown in FIGS. 10 and 11. First limb guide arm member  163  is pivotally mounted to extend from first wall  153  of longitudinal channel  150 , while second limb guide arm member  165  is pivotally mounted to extend from the second wall  155  of longitudinal channel  150 . Limb guide arm members  163 ,  165  are caused to concomitantly pivot between a first open position distal each other, and a second closed position proximate each other, via a second shaft and gear arrangement  171  in engagement with a second selectively actuated hydraulic actuator  162 , as shown in FIG.  14 . In the closed position, the curvature of limb guide arm members  163 ,  165  serve to enclose and bunch felled trees  108  within longitudinal channel  150  for proper shearing of limbs from felled trees  108  by limb stripping members  158 . However, inasmuch as first shaft and gear arrangement  170  is separate and distinct from second shaft and gear arrangement  171 , limb stripping members  158  can be selectively opened or closed irrespective of the pivotal movement of limb guide arm members  160 . Therefore, apparatus  100  can effectively shear limbs from bowed or untrue felled trees  108  without binding the apparatus, as limb guide arm members  160  are simply left in the open position to account for the variance in the longitudinal axis of bowed timber in these circumstances. 
     In greater detail, limb stripping members  158  generally comprise a curved limb stripping support member  168  rigidly attached to a rotatably mounted shaft, which is mechanically interconnected with selectively actuated hydraulic actuator  162 , as shown in FIGS. 12 and 14. Limb stripping support member  168  has a curved limb stripping blade  166  orthogonally attached thereto for engaging and shearing limbs from felled trees  108  transported through longitudinal channel  150 . Blade  166  includes a first shearing edge  167  positioned upon the terminating edge of blade  166  facing the rear portion  154  of apparatus  100 . 
     Further, it is contemplated within the scope of the present invention for limb guide members  160  to include an orthogonally attached second blade member  169  for assisting in the shearing of limbs from felled trees  108  upon longitudinal movement through channel  150 . However, the cutting edge of second blade member  169  is positioned facing front portion  152  of cutter head channel  150 , such that upon longitudinal movement of felled trees  108  from front portion  152  towards rear portion  154 , second blade member  169  of limb guide arm members  160  engages and shears limbs. As a result of first limb stripping blade  166  facing the rear portion  154  of cutter head assembly  112 , in conjunction with second limb stripping blade member  169  facing the front portion  152  of cutter head assembly  112 , delimbing apparatus  100  is capable of shearing limbs from felled trees  108  in two longitudinal directions. When felled trees  108  are urged to travel through longitudinal channel  150  in a longitudinal direction from rear portion  154  to front portion  152 , first stripping blade member  166  engages and strips limbs from felled trees  108 . Alternatively, when the operator reverses the longitudinal direction of movement of felled trees  108  within channel  150 , then second blade member  169  engages and strips limbs from felled trees  108 , thereby allowing for dual direction limb shearing. 
     Rear portion  154  of cutter head assembly  112  further includes a driven topping saw  176  for cutting felled trees  108  within longitudinal channel  150  to a predetermined length, as shown in FIGS. 7,  8 , and  9 . Topping saw  176  generally comprises a chain type blade linearly traveling on a blade track  178 , as is typically utilized in a chain saw arrangement. The blade track  178  is pivotally mounted to cutter head frame member  148  proximate rear portion  154  of longitudinal channel  150 . Additionally, the blade track is mechanically connected to a hydraulic cylinder, thereby allowing for selective pivotal motion of driven saw  176  from an upper position within shroud  180  to a lower cutting position. 
     In operation, delimbing apparatus  100  is generally transported to a location proximate the harvesting of raw timber. Trees are felled by various methods and then generally transported proximate delimbing apparatus  100  for processing. At rest, delimbing apparatus  100  is balanced such that the longitudinal axis of channel  150  is at an angle of approximately 30° with horizontal base frame member  116 , with the rear portion  154  of longitudinal channel  150  being positioned lower than the front portion  152  of longitudinal channel  150 . Apparatus  100  naturally returns to the optimum rest angle as a result of the positioning of the weight of the apparatus, as well as stop  146 . Inasmuch as topping saw  176  is positioned proximate the rear  154  of cutter head assembly  112 , the rear portion  154  of cutter head assembly  112  is sufficiently heavier than the front portion  152 . Thus, when at rest, apparatus  100  is urged to pivot towards the upwardly inclining rest angle, via rear portion  154  being heavier than front portion  152 , such that rear portion  154  pivots towards stop  146  until contacting such. Therefore, the rest angle is limited by stop  146 , which prevents the angle from increasing above the desired rest angle via direct contact with rear portion  154  of cutter head assembly  112 . This particular rest angle allows knuckle boom loader  104  to place felled trees  108  within longitudinal channel  150  without gouging the trunks of felled trees  108 , as first limb stripping blade  166  is generally angled away from the longitudinal axis of the tree trunk as a result of the rest angle of delimbing apparatus  100 . Upon placing felled trees  108  within longitudinal channel  150  with knuckle boom loader  104 , the operator of apparatus  100  selectively actuates hydraulic arm actuators  162 , thus causing limb stripping members  158  and limb guide arm members  160  to pivot to a closed position. In the closed position, curved limb guide arms  160  engage felled trees  108  bunching them together in a substantially circular orientation within channel  150 . With the felled trees  108  bunched within channel  150 , knuckle boom loader  104  pulls felled trees through channel  150  from rear portion  154  of channel  150  towards the front portion  152  of channel  150  causing first limb stripping blade  166  to engage and shear the limbs from felled tree  108 . If the desired limbs are not removed from the tree trunk with the first longitudinal movement, the operator may reverse the longitudinal motion of felled trees  108  within channel  150 , which causes second blade members  169  of limb guide arm members  160  to engage felled tree  108  to remove remaining limbs. 
     With the limbs removed as a result of one or more longitudinal movements, the operator then positions the end of the trunk of felled tree  108  against backstop  174  and engages topping saw  176 , which cuts the trunk of the tree to the desired length. 
     Hydraulic actuator  162  is then retracted, thus causing limb stripping members  158  and limb guide arm members  160  to pivot to the open position. The delimbed trees are removed from channel  150 , apparatus  100  returns to the rest angle, and the operator repeats the process for the next bunch of felled trees  108 . 
     It is to be understood that the form of the invention shown is a preferred embodiment thereof and that various changes and modifications may be made therein without departing from the spirit of the invention or scope as defined in the following claims.