Co-rotating multiple screw processor
AssigneeE. I. Du Pont de Nemours and Company
InventorDaniel G. Tynan
Life of this patent
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Abstract
This invention relates to a screw processor having multiple fully intermeshed co-rotating in-phase screws each provided with equal numbers of threads, each of said screws having longitudinally staged eccentric cross-sections preselected so that at least one thread of each screw spreads process material over the barrel bore and at least one other thread of each screw collects said process material and transfers it to a co-acting screw, which thereupon repeats the spreading-collecting-transfer cycle.
Claims7
A screw material processor embodying a housing, a multiplicity of parallel, intersecting, cylindrical bores in said housing and a multiplicity of fully intermeshed co-rotating in-phase screws, each operating in one of said bores, each screw being provided with equal numbers of threads, said threads comprising at least a first thread cut along a first helix in sliding contact with the bore of the processor housing with longitudinal axis coincident with the axis of rotation of said screw and at least one additional thread of reduced crest radius as compared with said first thread cut along a helical course concentric with said axis of rotation, said screws having longitudinally staged eccentric cross-sections the geometric centers of which lie on a helical curve having its central axis concentric with said axis of rotation, the amplitude of said helical curve being preselected to provide clearance of said additional thread with respect to said processor bore for spreading process material.
Dependencies are inferred from the claim text.