Method and apparatus for non-destructive testing the quality of manufacturing wood panels

The method of testing the quality of panels being manufactured in a mill comprising:

• a) locating on-line apparatus for the nondestructive testing of a panel;
• b) weighing a panel to be tested;
• c) clampingly engaging the panel such that a portion of the panel is cantilevered from the clamped portion thereof;
• d) causing complex vibrations to occur in the cantilevered portion of the panel so as to include both twisting and bending vibrations;
• e) sensing the complex vibrations and providing an out-put signal as a result thereof;
• and
• f) analyzing from said out-put signal, each of the bending and twisting vibrations induced into the panel and together with the mass information of the panel, determining from the panels modulus of elasticity and shear modulus, the quality of the panel being produced.

Apparatus for non-destructively testing the quality of manufactured panels made of wood products comprising:

• a) a bar-like clamp means for clampingly engaging and supporting a panel so as to have a portion of such panel cantilevered outwardly therefrom;
• b) means located at a position off-set from the axis of symmetry of the cantilevered portion of the panel for detecting complex vibrations induced into the cantilevered portion of the panel;
• and
• c) means for causing vibrations in said cantilevered portion of the panel including both bending and torsional vibrations.

Apparatus for non-destructively testing the quality of manufactured panels made of wood products comprising:

• a) a frame having a defined open area into and through which a panel can be fed endwise;
• b) a beam extending along an edge of said open area, said beam providing a clamping base that has a substantially smaller panel engaging area than the major surface area of the panel to be tested;
• c) bar-like means movably mounted to clampingly press a panel against said beam;
• and
• d) means located in selected spaced relation with respect to said beam, and at a position off-set from an axis of symmetry of a portion of a panel projecting in cantilever fashion from said beam, for detecting vibrations induced in the cantilevered portion of the panel and providing signals representative of bending and torsional vibrations in the panel that when analyzed, provide an indication of the quality of the panel.

Apparatus for non-destructively testing the quality of manufactured panels made of wood products comprising:

• a) a frame having at least one lower horizontal beam-like member on which a panel can rest;
• b) at least one upper horizontal beam-like member co-acting with said lower beam-like member to clampingly engage a panel therebetween, said panel having a portion projecting in cantilever fashion from where it is clampingly engaged,
• c) panel weighing means;
• and
• d) means for determining the thickness of the panel.

Apparatus for use in testing the quality of wood panels comprising:

• (a) Conveyor means for moving panels one after another along a selected path;
• (b) a weigh station located in the path of the panels to weight a panel as it moves along said selected path;
• (c) means for clampingly engaging a central portion of a panel, as it moves along said path, at a location downstream of said weight station, said clamping engaging a portion only of the panel with remaining portions being cantilevered therefrom;
• (d) means for inducing complex vibrations in said cantilevered portions of a panel projecting from the clamping means in a direction perpendicular to its direction of travel;
• (e) means for detecting the induced vibrations in the panel as it moves along said path;
• and
• (f) means to analyze formation obtained from said vibration detection means.

Apparatus for use in testing the quality of wood panels comprising:

• (a) a weigh station located in the path of panels moving by conveyor means along a selected path;
• (b) means for clampingly engaging a central portion of the panel as it moves along said path downstream of the weigh station, said clamping engaging a portion only of the panel with remaining portions being cantilevered therefrom;
• (c) means for inducing complex vibrations in the cantilevered portions of the panel projecting from the clamping means;
• (d) means for detecting the induced vibrations in the panel as it moves along said path;
• and
• (e) means to analyze information obtained from the vibration detector means, the weigh means and the panel thickness detecting means to determine the modules of elasticity and shear modulus of the panel.

A method of improving the manufacture of wood panels in a mill comprising providing on-line panel quality detection that includes:

• a) means to weigh a panel while moving;
• b) means to determine the thickness of the panel;
• c) means clampingly engaging a central portion of the panel as it moves along a selected path whereby the remaining portion is cantilevered respectively from each of opposite sides of a center portion of such path;
• d) means to induce bending and twisting vibrations in at least one of the cantilevered portions of the panel, and
• e) means to detect the vibrations induced into the cantilevered panel portion and provide signals that can be analyzed to indicate respectively the modulus of elasticity and shear modulus of the panel.

A system for testing the quality of a manufactured panel containing wood products comprising:

• (a) a panel conveying means for moving a panel along a selected path;
• (b) releasable elongate clamp means for temporarily clampingly engaging gand supporting a panel on said path to be tested nad in such manner that at least one portion of such panel is cantilevered from the clamp;
• (c) signal means providing output signals representative of complex vibrations in the panel at a location offset from an axis of symmetry of the cantilevered panel portion;
• nad
• (d) means for processing said output signals providing an analysis of each of bending and twisting vibrations and therefore enabling determination of the quality of the panel.