Abstract:
Log cutting is accomplished by energized cutting wires. The wires are energized at ultrasonic frequencies, provided in adjustable grid patterns to produce cut boards of desired sizes by passing a log through the energized grid. Grippers hold the log at each end and move the individual cut boards to storage, banding or drying stations.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from U.S. provisional patent application 60944497 filed Jun. 16, 2007. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    This invention relates to cutting of wood, for example, logs. 
         [0003]    Cutting of logs into usable dimensional lumber typically involves sawing with rotary saw blades. 
       SUMMARY OF THE INVENTION 
       [0004]    In accordance with the invention, thin wire-like cutting members are employed, energized or vibrated so as to cut through logs to provide dimensional lumber or desired cut configurations. 
         [0005]    Accordingly, it is an object of the present invention to provide an improved log cutting method and apparatus. 
         [0006]    It is a further object of the present invention to provide an improved log cutting system employing ultrasonic cutting. 
         [0007]    It is yet another object of the present invention to provide an improved wood cutting system employing thin energized cutting members. 
         [0008]    The subject matter of the present invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. However, both the organization and method of operation, together with further advantages and objects thereof, may best be understood by reference to the following description taken in connection with accompanying drawings wherein like reference characters refer to like elements. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a perspective view of a log being cut in accordance with the invention; 
           [0010]      FIG. 2  is a second perspective view of a log being cut in accordance with the invention, with different cutting sizes set; and 
           [0011]      FIG. 3  is an end sectional view of a log being cut in accordance with the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    The system according to a preferred embodiment of the present invention comprises adjustable cutting wires that are energized or vibrated to cut through logs and provide desired size boards or cants. 
         [0013]    Referring to  FIG. 1 , a perspective view of a log being cut in accordance with the invention, a log  10  is passed through a cutting grid  12  in the direction of arrow  14  (or the grid is moved through the log) to produce cut dimensional boards as may be observed at the cut end  16  of the log. 
         [0014]    The cutting grid  12  comprises a grid of energized or vibrated wires, the wires suitably being very thin, e.g., 0.065 inch or smaller. The wires are energized or vibrated to a high degree, suitably at ultrasonic frequencies, and thereby cut through the log as the log is moved through the grid. The grid provides linear accuracy to the cuts to generate cut boards or cants of desired dimension. 
         [0015]    The configuration of  FIG. 1  shows a grid pattern having regular spacing.  FIG. 2 , a second perspective view of a log being cut in accordance with the invention, with different cutting sizes set illustrates a different grid spacing and configuration pattern, whereby different dimension boards are produced as visible at cut end  16 ′. 
         [0016]      FIG. 3  illustrates an end sectional view showing another grid configuration  12 ″ cutting through a log  10 ″ to produce different board sizes. 
         [0017]    The grids  12  may also be adjustable to provide variable spacing and cutting configuration variations from log to log or during cutting of an individual log, wherein each (or some) wires are movable independently horizontally or vertically (x and y planes in the views of  FIG. 1  and  FIG. 2 ) so as to adjust the size of the cuts. This way, a desired cutting pattern may be employed for any individual log or groups of logs. An individual log may be analyzed in advance of cutting and the grid cutting pattern is adjusted to cut the size boards or cants from that log as desired to provide the proper size boards. Such choice of size can be based on board configurations that are desired, yield optimization (whether wood use or value of produced lumber based). 
         [0018]    In operation, each log is held by end grippers or fingers that continue to hold each board independently as the log is passing through the cutting grid and creating the cut boards. The fingers can carry the boards to other cutting grids or individual cutting wires to be trimmed, cut to other sizes or edged. 
         [0019]    Suitably, the individual boards remain gripped by the fingers until the board is stacked in an individual unit, banded for inventory/shipment or stacked for drying. Human handling is not required during the process. 
         [0020]    In accordance with the invention, logs from 4 to 20 inches diameter, for example, are cut to precise linear dimensions, suitably at speeds of 300 feet per minute or more. The adjustable cutting grid enables a variety of board sizes to be cut and for cuts to be customized to the configuration of individual logs. 
         [0000]    The invention provides advantage in that the logs can be broken down by passing once through the cutting grid as contrasted with conventional cutting systems that require multiple passes. The system is also able to break logs down into desired finish lumber product sizes, whereas conventional systems typically require resawing of larger size cut logs portions into finish product sizes. 
         [0021]    While ultrasonic vibration is desired as the excitation, lower frequency vibration is also possible. 
         [0022]    The desired wire size for the cutting grid is suitably under 0.065 inches. Also, while the illustrated embodiments employ a grid configuration of cutting wires, such cutting wires may be used singularly. Other band-like cutting member configurations maybe be employed in place of or in conjunction with wire cutting member. 
         [0023]    While a preferred embodiment of the present invention has been shown and described, it will be apparent to those skilled in the art that many changes and modifications may be made without departing from the invention in its broader aspects. The appended claims are therefore intended to cover all such changes and modifications as fall within the true spirit and scope of the invention.