Chipper roller and knives therefor
AssigneeLee Heydenreich
InventorPhilip J. Higby
Life of this patent
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Abstract
A chipper roller for a two-stage grinding machine has removable circular knives spaced axially and circumferentially in an array following a helical path of two turns about the surface of the roller. Each knife is in the form of a disc with a central aperture for accepting a fastening element and with a cutting edge on one side adjacent its periphery and an annular groove on the same side adjacent said edge creating a rake which cooperates with the walls of the groove to produce curls from chunks of material. The knives are fastened to the roller in recesses with only a minor portion of the knife projecting above the surface of the roller. Upon dulling of the exposed edge the knife can be rotated to bring a sharp section of the cutting edge into operation.
Claims7
A chipper roller, for use in a two-stage machine for granulating bodies of plastic and like material, having a cylindrical surface from which projects an axially and circumferentially spaced array of replaceable knives, characterized in that each of said knives consists of a circular disc having a cutting edge on one side at its periphery and a circumferential groove in said one side adjacent said cutting edge providing a rake at an angle greater than 40.degree. which cooperates with the walls of said groove such that said knives cut curls from said bodies of material, the cross-section of said groove having a smoothly curving contour free from slope discontinuities and reversals, and said discs are each removably mounted in respective recesses on said roller with a portion of said disc projecting beyond said surface and with said one side of said disc facing at least generally in the direction of intended rotation of said roller.
A knife for a chipper roller of a two-stage machine for granulating bodies of plastic and like material, said knife consisting of a circular disc having a cutting edge on one side at its periphery for cutting said plastic, a circumferential groove of circular cross-section in said one side adjacent said cutting edge providing a rake at an angle greater than 40.degree. which cooperates with the walls of said groove such that said knife when installed in said chipper roller in a granulating machine upon operation cuts curls from a body of plastic or like material, the cross-section of said groove having a smoothly curving contour free from slope discontinuities and reversals, and a central aperture for accommodating a fastening element for securing said knife to said chipper roller.
A machine for granulating bodies of plastic and like material comprising in combination a chipper roller with a cylindrical surface from which projects an axially and circumferentially spaced array of replaceable knives mounted in a chamber below a hopper for randomized production of chips from chunks of said material fed to said hopper, said knives each consisting of a circular disc having a cutting edge on one side at its periphery and a circumferential groove in said one side adjacent said cutting edge providing a rake at an angle greater than 40.degree. which cooperates with the walls of said groove such that said knives cut curls from said bodies of material, the cross-section of said groove having a smoothly curving contour free from slope discontinuities and reversals, and said discs are each removably mounted in respective recesses on said roller with a portion of said disc projecting beyond said surface and with said one side of said disc facing at least generally in the direction of rotation of said roller.
Dependencies are inferred from the claim text.