Screen classifiers

Claim 1

APPARATUS FOR CLASSIFYING A MIXTURE OF PARTICLES OF DIFFERENT SIZES INTO SIZE FRACTIONS WHICH COMPRISES A PLURALITY OF SUPERPOSED DOWNWARDLY INCLINED AND VERTICALLY SPACED WIRE MESH SCRENS, THE APPERTURES IN EACH SCREEN BEING LARGER THAN THE LARGEST PARTICLE IN THE PARTICLE MIXTURE FED THERETO, MEANS FOR SIMULTANEOUSLY VIBRATING SAID SCREENS, SAID PARTICLES WHEN INTRODUCED TO SAID SCREENS FROM THE TOP PASSING THROUGH THE APERTURES OF SOME OF SAID SCREENS WHILE COLLIDING WITH THE WIRE MESH OF OTHER SCREENS WHEREBY INDIVIDUAL PARTICLES WILL IN MOST CASES THE PROGRESSIVELY DEFLECTED BY THE COLLISIONS FORWARDLY ALONG THE SCREENS IN THE DIRECTION OF THEIR INCLINATION, THE NUMBER OF COLLISONS INCREASING WITH THE PARTICLE SIZE SUCH THAT THE LARGER PARTICLES ARE DEFLECTED A GREATER TOTAL DISTANCE FORWARDLY ALONG THE SCREENS THAN ARE THE SMALLER PARTICLES, BAFFLE MEANS COMPRISING AT LEAST ONE BAFFLE ELEMENT LOCATED BETWEEN ADJACENT SCREENS AND EXTENDING LATERALLY FOR THE FULL WIDTH OF SAID SCREENS BETWEEN THE OPPOSITE SIDES THEREOF AND IN THE REGULAR PATH THROUGH THE SCREENS OF A GIVEN PARTICLES SIZE FRACTION, THE OVER ALL LENGTH OF SAID BAFFLE MEANS IN THE DIRECTION OF SCREEN INCLINATION NOT EXCEEDING A COMPARATIVELY SMALL PORTION OF THE LENGTH OF SAID SCREENS AS MEASURED IN THAT SAME DIRECTION, SAID BAFFLE MEANS BEING IMPERVIOUS TO PARTICLES COARSER THAN SAID GIVEN PARTICLES SIZE FRACTION THEREBY TO INTERCEPT SUCH OF SAID COARSER PARTICLES AS ARE DEFLECTED THEREAGAINST IN A BACKWARDS DIRECTION FROM THE SCREEN NEXT-ABOVE SAID BAFFLE MEANS AND TO REDIRECT SAID COARSER PARTICLES IN SAID FORWARD DIRECTION TO THE SCREEN NEXT-BELOW SAID BAFFLE MEANS, AND MEANS FOR COLLECTING SAID PARTICLES ACCORDING TO THEIR VARIOUS SIZE FRACTIONS.