METHOD FOR GRINDING SCREWS Russian patent published in 2007 - IPC B23G1/38 

FIELD: manufacturing processes in machine engineering, finish abrasive working of precise screws of hard-to-work materials.

SUBSTANCE: method comprises steps of mounting grinding wheel by inclination angle equal to lead angle of turns of worked screw; imparting to grinding wheel independent rotation and lengthwise feed equal to pitch of ground screw; using rest. In order to enhance quality, efficiency and accuracy of grinding, three wheels equally arranged in cross plane and mutually spaced in axial direction by distance equal to 1/3 of screw pitch are simultaneously used for grinding. Rotation axes of wheels are inclined relative to blank axis by angle equal to lead angle of screw turns. Head is used as rest for mounting wheels having individual drive units with possibility of self-aligning while providing the same radial feed of them by means of spiral-rack mechanism having three rack cleats. Head also includes central spiral disc engaged with said rack cleats and with small cone pinion whose rotation provides radial feed of wheels.

EFFECT: enhanced efficiency of grinding screws at improved quality and accuracy.

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