The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 15, 1990
Filed:
Sep. 14, 1987
Friend K Bechtel, Moscow, ID (US);
James R Allen, Pullman, WA (US);
Metriguard, Inc., Pullman, WA (US);
Abstract
A non-destructive testing system for lumber involves measurement of grain angle about a board and transformation of the measured grain angle values to extract features indicative of knot identification, grain angle perturbations or strength of the board. Individual boards can then be processed for grading or sorting purposes as a function of the extracted features. Specific features utilized for knot identification are curl, divergence, and novel transformations termed gradient, edges and knots, as well as various pattern matching techniques. Strength estimation involves transformations pertaining to failure distance, which is a function of board tensile strength. Failure distance can be computed by an ellipsoidal model, a search model or a tracks model. When utilized in conjunction with conventional bending test procedures, highly accurate strength estimation is achieved by the described system.