Fabrication System For Continuously Fabricating Graded Extended Length Lumber With Maximum Grade Utilization Of Input Low Quality Raw Lumber

Abstract

An extended length graded lumber fabrication system features a number of fabrication stages along a substantially continuous fabrication path providing high through put fabrication of graded lumber of extended length from low quality raw lumber. The fabrication stages include reject recognition stages, a supply lumber grading stage, a finger jointing stage and a final grading stage for the extended length lumber. The fabrication system is configured in conjunction with the particularities of low quality raw lumber to minimize grade fluctuations, increase grade bandwidth and minimize raw lumber waste during fabrication of extended length graded lumber, which may be used in wooden truss joists. The use of low quality raw lumber cut from small diameter tree trunks is environmentally beneficial. It contributes to preserve old growth and to use lighter and environmentally less invasive timber harvesting machinery and techniques.

1 . An extended length graded lumber fabrication system comprising: 
 a. a continuous input-to-output fabrication path;    b. a lumber reject recognition stage along said continuous input-to-output fabrication path;    c. a supply lumber grading stage along said continuous input-to-output fabrication path;    d. a grade sorting stage along said continuous input-to-output fabrication path behind said lumber reject recognition stage and said first supply lumber grading stage;    e. a single grade lumber length extension stage along said continuous input-to-output fabrication path and following said grade sorting stage; and    f. an extended length lumber grading stage along said continuous input-to-output fabrication path and behind said single grade length extension stage.    
   
   
       2 . The extended length graded lumber fabrication system of  claim 1 , further comprising a secondary graded lumber buffer storage path diverting off said continuous input-to-output path behind said grade sorting stage and rejoining said continuous input-to-output fabrication path before said single grade lumber length extension stage.  
   
   
       3 . The extended length graded lumber fabrication system of  claim 1 , wherein said reject recognition stage is behind said first lumber grading stage along said continuous input-to-output fabrication path, and wherein said extended length graded lumber fabrication system further comprises: 
 a. a reject cutout and grade separation stage following said reject recognition stage along said continuous input-to-output fabrication path;    b. a tertiary graded shortened lumber buffer storage path diverting off said continuous input-to-output fabrication path behind said reject cutout stage and rejoining said continuous input-to-output fabrication path before said single grade lumber length extension stage.    
   
   
       4 . The extended length graded lumber fabrication system of  claim 1 , wherein at least a portion of said extended length graded lumber is a chord of a truss joist.  
   
   
       5 . The extended length graded lumber fabrication system of  claim 1 , wherein at least a portion of said extended length graded lumber is a web strut of a truss joist.  
   
   
       6 . The extended length graded lumber fabrication system of  claim 1 , wherein said extended length graded lumber has a spacing between finger joints of less than 1 foot and down to about 4 inches.  
   
   
       7 . The extended length graded lumber fabrication system of  claim 1 , wherein a first lumber grader is provided at said supply lumber grading stage and wherein a second lumber grader is provided at said extended length lumber grading stage.  
   
   
       8 . The extended length graded lumber fabrication system of  claim 1 , wherein a single lumber graded is at said supply lumber grading stage coinciding with said extended length lumber grading stage and wherein said continuous input-to-output fabrication path crosses at said supply lumber grading stage coinciding with said extended length lumber grading stage.  
   
   
       9 . An extended length graded lumber fabrication system comprising: 
 a. a continuous input-to-output fabrication path;    b. a lumber reject recognition stage along said continuous input-to-output fabrication path;    c. a supply lumber grading stage along said continuous input-to-output fabrication path;    d. an automated lumber sorting stage along said continuous input-to-output fabrication path following said lumber reject recognition stage and said first raw lumber grading stage;    e. a secondary graded lumber buffer storage path diverting off said continuous input-to-output fabrication path at said automated lumber grading stage;    f. a reject cutout and grade separation saw following said automated lumber sorting stage;    g. a tertiary graded shortened lumber buffer storage path diverting off said continuous input-to-output fabrication path at said reject cut out and grade separation saw;    h. a storage path switching stage along said secondary graded lumber buffer storage path and said tertiary buffer storage path;    i. a single grade lumber length extension stage along said continuous input-to-output fabrication path and following said grade sorting stage; and    j. an extended length lumber grading stage along said continuous input-to-output fabrication path and following said single grade length extension stage;    wherein said secondary graded lumber buffer storage path and said tertiary graded shortened lumber buffer storage path rejoin said continuous input-to-output fabrication path before said single grade lumber length extension stage.    
   
   
       10 . The extended length graded lumber fabrication system of  claim 9 , wherein at least a portion of said extended length graded lumber is a chord of a truss joist.  
   
   
       11 . The extended length graded lumber fabrication system of  claim 9 , wherein at least a portion of said extended length graded lumber is a web strut of a truss joist.  
   
   
       12 . The extended length graded lumber fabrication system of  claim 9 , wherein said extended length graded lumber has a spacing between finger joints of less than 1 foot and down to about 4 inches.  
   
   
       13 . The extended length graded lumber fabrication system of  claim 9 , wherein a first lumber grader is provided at said supply lumber grading stage and wherein a second lumber grader is provided at said extended length lumber grading stage.  
   
   
       14 . The extended length graded lumber fabrication system of  claim 9 , wherein a single lumber graded is at said supply lumber grading stage coinciding with said extended length lumber grading stage and wherein said continuous input-to-output fabrication path crosses at said supply lumber grading stage coinciding with said extended length lumber grading stage.  
   
   
       15 . A fabrication system for continuously fabricating multiple grade extended length lumber from low quality variable length supply lumber, said fabrication system comprising: 
 a. a continuous input-to-output fabrication path along which lumber pieces of predetermined cross section propagate;    b. a multiple lengths supply lumber in-feed stage at begin of said continuous input-to-output fabrication path, said multiple lengths supply lumber in-feed stage being configured for receiving and in-feeding supply lumber in form of said lumber pieces in an original length and shorter;    c. a moisture measuring stage following said multiple lengths supply lumber in-feed stage along said continuous input-to-output fabrication path, wherein at said moisture measuring stage a moisture information is associated with said lumber pieces;    d. a lumber appearance inspection and out-sorting stage following said multiple lengths supply lumber in-feed along said continuous input-to-output fabrication path;    e. a supply lumber grading stage following said lumber appearance inspection and out-sorting stage along said continuous input-to-output fabrication path, wherein at said lumber grading stage a grade information is associated with said lumber pieces;    f. a grain inconsistencies scanning stage following said lumber appearance inspection and out-sorting stage along said continuous input-to-output fabrication path, wherein at said grain inconsistencies scanning stage a grain inconsistency information is associated with said lumber pieces;    g. a grade sorting stage following said grain inconsistency scanning stage along said continuous input-to-output fabrication path, wherein at said grade sorting stage said lumber pieces are computerized controlled diverted onto a secondary graded nominal length lumber buffer storage path in accordance with at least one of said grade information and said grain inconsistency information;    h. a reject cutout and grade separation stage following said grade sorting stage along said continuous input-to-output fabrication path, wherein at said reject cutout grade separation stage said lumber pieces are computerized controlled diverted towards a cutout saw and onto a tertiary shortened length graded lumber buffer storage path in accordance with said grade information and said grain inconsistency information, and wherein said cutout saw is computerized controlled in accordance with said grain inconsistency information such that portions of said lumber pieces having a grain failure are removed;    i. a grade selective in-feeding stage at which said secondary graded original length lumber buffer storage path and said tertiary graded lumber shortened length buffer storage path are rejoining said continuous input-to-output path, and wherein at said grade selective in-feeding stage at least one of said graded original length lumber and said shortened length graded lumber of a predetermined single grade are in-fed into said continuous input-to-output path;    j. a single grade lumber length extension stage following said grade selective in-feeding stage along said continuous input-to-output fabrication path, wherein said single grade lumber extension stage features: 
 i. a finger jointer joining said at least one of said graded original length lumber and said shortened length graded lumber into a propagating endless lumber;  
 ii. a finger joint proof loader at which a finger joint failure information is associated with an endless lumber location;  
 iii. a travel saw computerized controlled cutting said endless lumber into said extended length lumber and out-cutting failed finger joints in accordance with said finger joint failure information; and  
   k. an extended length lumber grading stage along said continuous input-to-output fabrication path and following said single grade length extension stage.    
   
   
       16 . The fabrication system of  claim 15 , further comprising a reject back insertion path diverting off said continuous input-to-output fabrication path behind said travel saw, wherein said reject back insertion path terminates at said multiple lengths supply lumber in-feed stage such that cutout lumber having a failed finger joint is reinserted at begin of said continuous input-to-output path.  
   
   
       17 . The fabrication system of  claim 15 , wherein at least a portion of said extended length graded lumber is a web strut of a truss joist.  
   
   
       18 . The fabrication system of  claim 15 , wherein at least a portion of said extended length graded lumber is a chord of a truss joist.  
   
   
       19 . The extended length graded lumber fabrication system of  claim 15 , wherein said extended length graded lumber has a spacing between finger joints of less than 1 foot and down to about 4 inches.  
   
   
       20 . A method for maximizing graded lumber output from low quality input lumber, said method comprising the steps of: 
 a. providing generic lumber pieces;    b. inspecting lumber pieces for at least one of defects, excess moisture and insufficiencies and removing rejected lumber pieces;    c. initial lumber piece grading into grades A-N and associating a grade information with said lumber pieces;    d. lumber piece grade sorting in association with said grade information and buffer stacking grades B-N lumber pieces;    e. grade selective in-feeding of grade A-N lumber pieces;    f. finger jointing into single grade A-N endless lumber;    g. proof loading endless lumber and associating finger joint failure information with endless lumber location;    h. lengthening single grade A-N endless lumber into extended length and removing failed finger joints in association with said finger joint failure information; and    i. final lumber piece grading.    
   
   
       21 . A method for maximizing graded lumber output from low quality input lumber, said method comprising the steps of: 
 a. providing generic lumber pieces;    b. in-feeding generic lumber pieces;    c. scanning moisture of generic lumber pieces;    d. inspecting appearance of lumber pieces and removing rejected and excess moisture lumber pieces;    e. drying excess moisture lumber pieces and reinserting said dried lumber pieces at step b;    f. initial lumber piece grading into grades A-N and associating initial grade information with lumber pieces;    g. grain inconsistencies scanning and associating grain inconsistency information with lumber pieces;    h. nominal length lumber grade sorting in association with said initial grade information, said moisture information and said grain inconsistency information and secondary buffer stacking grade B-N nominal length lumber;    i. grain inconsistencies and excess moisture removing in association with said moisture information and said grain inconsistency information and tertiary buffer stacking grade A-N cut lumber in A-N grade and a-n length Aa-Nn stacks;    j. grade selective in-feeding of grade A-N lumber pieces;    k. finger jointing into single grade A-N endless lumber;    l. proof loading endless lumber and associating finger joint failure information with endless lumber location;    m. lengthening single grade A-N endless lumber into extended length, removing failed finger joints in association with said finger joint failure information and return in-feeding failed joint lumber at said step of in-feeding generic lumber pieces; and    n. final lumber piece grading.