Abstract:
The present invention provides an apparatus and method of processing logs. The apparatus includes a linkage having a boom and a stick. The boom is adapted for attachment to a support platform. A delimbing assembly is connected to the boom, and a loading assembly is connected to the stick. The method includes the steps of picking up a log, delimbing the log, and placing the log into a desired position.

Description:
TECHNICAL FIELD 
     The present invention relates generally to an apparatus and method of processing logs, and, more specifically, to an apparatus and method which provides for delimbing, cut-to-length, and log handling functions in a single assembly. 
     BACKGROUND 
     In the forestry industry, it is common practice for a logging operator to cut down trees by hand or using a harvester-type machine, transport the logs (logs is used herein to refer to felled trees) to a central processing/loading location using a forwarder or the like, delimb the logs with a delimbing machine or by hand, optionally cut the logs to length by hand or using a work machine, and load the whole or cut logs onto a truck or other transport using a log loader. 
     As is intuitively obvious, this sort of operation requires a great number of different work machines which must be purchased and maintained, necessitating a wide range of replacement parts be available. The machines also are frequently idle when the supply feed of logs is uneven, and a breakdown of one machine can cause the entire operation to stop entirely. All of the above may cause the logging operator to incur great expense and loss of productivity. 
     It is thus common in the art for work machines to perform more than one of the aforementioned functions, in an attempt to reduce the number of machines and operators needed for a successful logging operation. However, many of these combination machines are mechanically quite complicated and perform multiple jobs poorly in comparison to single-function machines, which has resulted in a tendency for logging operators to continue to use the single-function machines. 
     Such a combination machine is disclosed in U.S. Pat. No. 5,628,354, issued May 13, 1997 to Aloysius Kingston (hereafter referenced as &#39;354). &#39;354 relates to a tree delimbing and severing attachment, which is optionally mounted on the trailer of a forwarder. The &#39;354 machine may be used to process felled trees at the felling location and to carry logs therefrom to a forest road and then the central processing/loading location. &#39;354, however, may have the disadvantages of scattering the discard material about the logging site, requiring multiple grapple cycles to transfer the cut-to-length logs to the forwarder trailer, and requiring a highly skilled operator to maneuver and delimb the logs in the often tight confines of a felling location, among others. 
     Accordingly, the art has sought a method and apparatus of processing logs which: successfully and efficiently combines several logging work functions in one apparatus; allows for logs to be processed in a central location which may be chosen to eliminate spacial constraints; performs several operations without requiring multiple instances of handling/moving the same log; may be used in a timely and efficient manner; and is more economical to manufacture and use. 
     The present invention is directed to overcoming one or more of the problems as set forth above. 
     SUMMARY OF THE INVENTION 
     In an embodiment of the present invention, an apparatus for processing logs is provided. The apparatus includes a linkage having a boom and a stick. The boom is adapted for attachment to a support platform. A delimbing assembly is connected to the boom, and a loading assembly is connected to the stick. 
     In an embodiment of the present invention, a method of processing logs using a log processing apparatus is provided. The method includes the steps of picking up a log, delimbing the log, and placing the log into a desired position. 
     In an embodiment of the present invention, a work machine for processing and loading logs is provided. The work machine includes a body, an engine, propulsion means, an operator compartment, a linkage connected to the body, and a log processing assembly connected to at least one of the linkage and the body. The log processing assembly includes a delimbing portion and a loading portion. 
     In an embodiment of the present invention, a method of processing logs is provided. The method includes the steps of picking up a log with a loading assembly of a work machine and delimbing the log with a delimber of the work machine. The method also includes the steps of determining at least one of a total length value, a partial length value, and a girth value of the log with a measuring system of the work machine and determining a desired length or lengths of the log using at least one of the total length value, partial length value, and girth value of the log. The method also includes the steps of cutting the log to the desired length or lengths with one or more saws of the work machine and placing the length or lengths of the log in a predetermined position with the loading assembly of the work machine. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of the apparatus of a preferred embodiment of the present invention; and 
     FIG. 2 is a side view of the apparatus mounted on a work machine of a preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION 
     A preferred embodiment of the present invention provides an apparatus and method of processing logs. The following description uses an excavator as an example only. This invention may be applied to other types of work machines. 
     Referring to FIG. 1, a log processing apparatus  100  is provided. The apparatus  100  has a linkage  102 . The linkage  102  includes a boom  104  and a stick  106 . The boom  104  is attachable to a support platform (not shown). The stick  106  is connected to the boom  104  for relative movement thereto. The apparatus  100  also includes a delimbing assembly  108  and a loading assembly  110 . The delimbing assembly  108  and the loading assembly  110  are each attached to one of the boom  104  and stick  106 . Preferably, the delimbing assembly  108  is attached to the boom  104 , and the loading assembly  110  is attached to the stick  106 . 
     The delimbing assembly  108  preferably includes a log delimbing support system  112 , delimbing knives  114 , and a butt saw assembly  116 . The log delimbing support system  112  acts to provide support for the log as it is being delimbed. The term “delimbing” is meant to refer to any combination of delimbing and debarking operations herein. A preferred embodiment of the delimbing support system  112  is shown in FIG.  1 . This embodiment includes a support trough  118 , a hold-down roller  120 , and a drive mechanism  122 . 
     The loading assembly  110  preferably includes a grapple  124 , a topping saw assembly  126 , and a log loading support system  128 . The log loading support system  128  acts to provide leverage and support for the log as it is being loaded and may act to steady the log. A preferred embodiment of the log loading support system  128  is shown in FIG.  1 . This embodiment includes a commonly used heel assembly  130 . 
     Optionally, the apparatus  100  also includes a log measurement system (not shown). The log measurement system has at least one measurement sensor  132  and produces at least one log measurement signal. This signal indicates one or more of a longitudinal characteristic (“length”) or a diametrical characteristic (“girth” or “diameter”), of all or a portion of the log. 
     In a preferred embodiment of the present invention, shown in FIG. 1, the linkage  102  includes one or more linkage joints  132 ′ at the connections between the various components of the linkage  102 , and each linkage sensor  132 ′ includes a measurement sensor  132 . The measurement sensors  132  can measure the relative angles of the components of the linkage  102 , and, knowing the length of the components, the log measurement system can determine a position in space of the grapple  124 , the topping saw assembly  126 , the butt saw assembly  116 , or any other portion of the apparatus  100 . Once the relative position of the components of the apparatus  100  is known, one skilled in the art can determine the length of the log or a portion thereof being processed by the apparatus  100 , and thereby accurately cut the log to a desired length or lengths. 
     The butt saw assembly  116  and the topping saw assembly  126  can be bar saws, disk saws, shears, chainsaws, flails, or any other known means to sever or cut the log in a desirable manner. Each of the butt saw assembly  116  and the topping saw assembly  126  can be mounted at any convenient location on the apparatus  100 . The presence of either or both of a butt saw assembly  116  and a topping saw assembly  126  is not required for proper function of the apparatus  100 . 
     Referring now to FIG. 2, the apparatus  100  is shown mounted on a work machine  200 . The work machine  200  shown in FIG. 2 is commonly known as an excavator or hydraulic excavator. The work machine  200  includes a body  202 , an engine  204 , propulsion means  206 , an operator compartment  208 , and the apparatus  100 . In FIG. 2, the work machine  200  acts as a support platform for the apparatus  100 , but various other embodiments of a support platform can be envisioned, such as, but not limited to, a stanchion, pier, platform, trailer, footing, and the like. 
     While aspects of the present invention have been particularly shown and described with reference to the preferred embodiment above, it will be understood by those skilled in the art that various additional embodiments may be contemplated without departing from the spirit and scope of the present invention. For example, the log could have been previously at least partially delimbed, the log measurements could be obtained differently, or the linkage could have more sections in addition to the boom and stick. However, a device or method incorporating such an embodiment should be understood to fall within the scope of the present invention as determined based upon the claims below and any equivalents thereof. 
     INDUSTRIAL APPLICABILITY 
     In the following description, the apparatus  100  of the present invention will be assumed to be mounted upon a work machine  200  and located at a central processing/loading location. The apparatus  100  will be referred to as a “processor”  100 . These terms are used for convenience of reference and should not be construed to limit the scope of the invention in any way. The following describes the operation of a preferred embodiment of the present invention. 
     During a logging operation at a forest location, trees are cut by a harvester and the resulting logs are transported to the central processing/loading location by a forwarder. The logs, still carrying-bark and limbs, are unloaded from the forwarder. The processor  100  then picks up each log with its grapple  124  and feeds it into the delimbing assembly  108  in a known manner. The delimbing knives  114  remove the limbs and/or bark from the log as the log is passed between them, either on the intake or output pass of the log. When the log is sufficiently seated in the delimbing assembly  108 , either the grapple  124  or a combination of the hold-down roller  120  and a drive mechanism  122  provides motive power to draw the log (intake pass) between the delimbing knives  114  in a direction away from the loading assembly  110  while a support trough  118  serves to support the weight of the length of the log. A motive power is then applied to move the log in a direction toward the loading assembly  110  (output pass). Optionally, a topping saw assembly  126  and/or butt saw assembly  116  may be employed in a known manner, manually or automatically, to remove one or more ends of the log as the tree is being delimbed or loaded. 
     In the case of a whole-tree operation, once the log is delimbed, it is removed from the delimbing assembly  108  on its output pass by the loading assembly  110  and placed/loaded in a predetermined location by the operator, using the loading assembly  110 . 
     If the log is being processed for a cut-to-length operation, a measurement system may be employed to measure the log&#39;s length, partial length, girth, or any other property to determine when a desired portion of the log has passed from the delimbing assembly  108  on the output pass. The delimbed log is removed from the delimbing assembly  108  as above, until a desired length of the log has been removed from the delimbing assembly  108 . The topping saw assembly  126  and/or butt saw assembly  116  may then be employed to cut the log at that position, thus producing a child log from the parent log. The child log is then placed into a predetermined location as above and the parent log continues its output pass. This operation may be repeated as needed to produce a desired number of child logs. 
     The measurement system also may be used to monitor log production, waste generation, or any other properties which may be determined from the log&#39;s length, partial length, and girth. 
     The apparatus and method of certain embodiments of the present invention, when compared with other methods and apparatus, may have the advantages of: successfully and efficiently combining several logging work functions in one apparatus; allowing for logs to be processed in a central location which may be chosen to eliminate spacial constraints; performing several operations without requiring multiple instances of handling/moving the same log; being used in a timely and efficient manner; and being more economical to manufacture and use. Such advantages are particularly worthy of incorporating into the design, manufacture, and operation of forestry machines. In addition, the present invention may provide other advantages that have not yet been discovered. 
     It should be understood that while a preferred embodiment is described in connection with an excavator, the present invention is readily adaptable to provide similar functions for other work machines. Other aspects, objects, and advantages of the present invention can be obtained from a study of the drawings, the disclosure, and the appended claims.