METHOD OF MAKING INTERMEDIATE BLANK OF ELECTRIC MOTOR COMMUTATOR Russian patent published in 1997 - IPC

FIELD: plastic metal working. SUBSTANCE: method of making intermediate blank of electric motor commutator includes steps of pressing out sleeve of sized blank, forming supporting lugs of commutator segments arranged on its inner lateral surface by means of punch whose working end has longitudinal grooves with cross section corresponding to that of said supporting lugs; at first placing sized rod-type blank to cylindrical die with one closed end and inserting said punch at lengthwise pressing out into said blank along part of length of its longitudinal grooves; drawing blank by means of the same punch (with blank onto it) through drawing die with sizing round hole until formation of sleeve with cavity whose depth is equal to length of commutator segments and their petals; removing bottom of said sleeve and turning its ends. EFFECT: enhanced efficiency. 4 dwg