Improvements in or relating to commutators for electric motors and the like

Abstract

Abstract 563,228. Commutators for dynamoelectric machines. LIMIT ENGINEERING CO., Ltd., and COLLINS, A. L. Feb. 11, 1943, No. 2315. [Class 35] In the method of producing a commutator by forming upon a metal contact member a row of undercut lugs, moulding a block of insulating material around and between the lugs and then splitting the contact member between the lugs into a series of segments, the undercut shape is imparted to the lugs by squeezing them between dies prior to the moulding operation. In one method, a copper strip 10, Fig. 1, formed initially with transverse projections 11, is bent into a ring, Fig. 3 and squeezed between dies 13, 13a, Fig. 5, having end faces 14, 14a which impart a trapezoidal shape to the projections. The space between the ring and an inner metal bush 16, Fig. 6, is then filled with moulded synthetic resin 15 and the commutator finished by cutting slots 18, Fig. 7, in the ring between the projections 11, the joint 17, Fig. 6, between the ends of the strip serving to position the first cut. In modified processes the projections may be formed after the strip has been bent into a ring, or the undercut shape may be imparted to the projections whilst the strip is straight. A thick walled metal tube having internal projections may be employed instead of a bent strip.

Inventors

No inventors recorded.

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