Apparatus for proportioning and mixing particulate materials

Claim 1

Apparatus for proportioning and mixing particulate or granular primary and secondary plastic ingredient materials for making a mixture of granular plastic material suitable for further procesSing comprising primary granular ingredient metering means for metering virgin or reground plastic granules used in forming the body or major mass part of the granular plastic mixture, said primary ingredient metering means including at least one primary ingredient metering unit including a radially bladed horizontally journalled rotor, housing structure defining intake and discharge openings respectively superjacently and subjacently of said rotor, prime mover means for powering said rotor, first drive means interconnecting said prime mover means and said rotor for driving said rotor at a selected constant speed, said primary ingredient metering unit upon rotation of said rotor being operative for metering a certain quantity of granular primary ingredient material gravitatingly downwardly through said rotor and out of said discharge opening of said housing structure, secondary ingredient metering means for metering color concentrate granules for use in coloring the major mass part of the mixture of the primary granular ingredient issuing from the discharge opening of said primary ingredient metering unit, said secondary ingredient metering means including a metering member having structure defining at least one small measuring chamber of a certain volume adapted to be filled and emptied cyclically alternatingly of color concentrate granules, housing structure arranged about said metering member defining intake and discharge openings arranged respectively contiguous of the measuring chamber of said metering member, mechanical action means for guidingly constraining said metering member in continuous cyclic movement and for movement of said measuring chamber into and out of communication alternatingly cyclically with said intake and discharge openings of said secondary ingredient metering means housing structure, second drive means interconnecting in drive connection the rotor of said primary ingredient metering unit and the metering member of said secondary metering means, said secondary metering means being adapted for metering a specific quantity of granular color concentrate ingredient material cyclically into and out of the metering member chamber upon each revolution of said primary metering unit rotor and downwardly gravitatingly out of the discharge opening of said secondary ingredient metering means, and mixing hopper means arranged underneath said discharge openings respectively of said primary and secondary ingredient metering means for receiving the granular material issuing from said discharge openings and for mixing the primary and secondary granular ingredient material into a proportioned mixture; said metering member means of said secondary ingredient metering means including a metering plunger, recess structure defining an annular measuring chamber arranged concentrically about the axis of said plunger, said means guidingly constraining said metering plunger including stationary bushing means mounting said plunger in a vertical disposition substantially subjacently of said discharge opening of said secondary ingredient metering means, said metering plunger being adapted to vertically move upwardly to fill said measuring chamber with plastic granules and to move downwardly to release the measured quantities of granules through said discharge opening downwardly into said hopper means, and wherein said second drive means interconnecting the rotor of said primary ingredient metering unit and said metering plunger includes a double-acting piston-cylinder assembly stationarily mounted subjacently of said plunger, link means interconnecting the lower end of said plunger with the piston of said pistoncylinder assembly for common vertical reciprocal movement of said piston and plunger, an air supply line connectable with a source of compressed air, conduit means interconnecting said air supply line and said piston-cylinder assembly, air valve means interposedly arranged in said air conduit means for directing compressed air to one side or the other side of the piston of said piston-cylinder assembly respectively for either raising or lowering said metering plunger, and including actuating means operatively interconnecting said rotor and said air valve means for causing synchronous reciprocating movement of said plunger with rotative movement of said rotor.