Method and apparatus for producing particle board and the like

Claim 1

IN A PROCESS FOR MANUFACTURING A COMPOSITE PARTICLE BOARD OF PARTICULTE MATERIAL HAVING OPPOSITE SURFACE LAYERS OF RELATIVELY FINER SIZE PARTICLES AND AN INTERVENING CORE LAYER OF COARSER SIZE PARTICLES AND WHEREIN LAYERS OF PARTICLES ARRANGED ON A PARTICLE RECEIVING SURFACE ARE SUBJECTED TO PRESSING AND HEAT TO FORM THE PARTICLE BOARD, THE STEPS OF SEPARATING PARTICULATE MATERIAL INTO AT LEAST TWO VERTICALLY SEPARATED GROUPS OF TWO DIFFERENT SELECTED SIZE RANGES, CONVEYING THE TWO GROUPS OF PARTICLES IN SEPARATE GROUPS TO A DISCHARGE STATE, AND MOVING THE SEPARATED GROUPS OF PARTICLES IN UNISON WITH RESPECT TO AN ELONGATED PARTICLE RECEIVING SURFACE THROUGH AN ADVANCE STROKE IN A FIRST DIRECTION LENGTHWISE OF THE SURFACE OVER A DISTANCE CORRESPONDING TO THE LENGTH OF THE DESIRED PARTICLE BOARD AND THEN THROUGH A RETURN STROKE OF SIMILAR LENGTH IN THE OPPOSITE DIRECTION WHILE DISTRIBUTING THE PARTICLES OF ONE SAID GROUPS ONTO THE RELATIVELY MOVING PARTICLE RECEIVING SURFACE ALONG A DISCHARGE PATH SPANNING THE WIDTH OF THE PARTICLE RECEIVING SURFACE AND CONCOMITANTLY DISTRIBUTING THE PARTICLES OF THE OTHER OF SAID GROUPS IN SPACED RELATION LENGTHWISE OF THE SURFACE TO THE DISCHARGE PATH OF SAID FIRST GROUP, THE COARSER SIZE DISCHARGE PATH BEING SPACED IN TRAILING RELATION TO THE FINER SIZE DISCHARGE PATH DURING SAID ADVANCE STROKE AND IN LEADING RELATION TO THE FINER SIZE DISCHARGE PATH DURING SAID RETURN STROKE TO LAY THE PARTICLES IN AN ORDER FORMING AN INTERVENING CORE LAYER OF COARSER PARTICLES DISPOSED BETWEEN A PAIR OF LAYERS OF FINER PARTICLES.