Method of stamping laminations

Claim 1

In the art of making transformer laminations from a continuous strip of magnetizable material, wherein a complete lamination layer consists of large and small opposed complementary E''s, each E having a base and legs extending laterally from the front edge of the base, each outer leg having a width equal to half the width of the center leg and being equally spaced therefrom, the legs of a large E being equal in length, the legs of a mating small E being equal in length, the bases of both E''s being equal in width and length, a pair of complementary E''s in a lamination layer being disposed with their legs extending toward each other in abutting relation and the bases being paralleled with the rear of each base being on the outside of one lamination layer; said continuous strip of material having its width equal to two component widths, one component width being equal to twice the width of the base of one E plus the length of the leg thereof, the other component width being equal to twice the width of the base of the other complementary E plus the length of the leg thereof, the width of such strip being constant and an imaginary dividing line between such component widths being straight and extending longitudinally of the continuous strip parallel to the strip edges; there being on one side of such dividing line said one component strip portion accommodating a pattern having two rows of interlocked equal E''s, the rows extending longitudinally of the strip and the E''s of the outer row having their bases extending continuously along the strip edge and imaginary lines extending transversely of the two outer rows of the continuous strip at regular intervals corresponding to the length of an E and a right angles to the strip edges, and the bases of the E''s in the inner row extending continuously along the dividing line and all the legs extending transversely of the strip; said other component strip portion accommodating a pattern having tWo rows of complementary equal E''s arranged in the same manner as in the one component strip portion, the E pattern being such that the legs of the E''s in the two outer rows extending along the outer edges of the entire magnetizable material strip extend toward each other in transverse alignment; the inner rows of E''s having their legs aligned but extending away from each other, the method which includes the following steps, a. stamping small generally circular apertures in the metal strip along the imaginary dividing line at regular intervals corresponding to the length of an E, b. stamping small generally semi-circular apertures in the metal strip along the outer edges of the two outer rows at each of said transversely extending imaginary lines, the base of each said generally semi-circular apertures being coincident with the outer edge of the strip. c. stamping, from one large outer E row and one small outer E row on said strip, one large E and one small E, originally in transverse alignment on said strip with the transverse ends of said stamped E''s terminating at said small apertures to leave E''s in the remaining two inner rows attached to each other in succession, along each of said remaining two rows, d. piloting the strip metal through successive stamping stations by pilot members extending through the strip metal at regions where metal has been removed, e. shearing E from the remaining inner row along said transverse imaginary lines, f. controlling the discharge and stacking of stamped E''s so that a small E and complementary large E, originally transversely aligned in the original strip are paired to make a lamination layer.