Abstract: The invention concerns a transformer lamination of the EI type, having a center leg, two outer legs and two yokes connecting these legs and having joints between one side of the center leg and between one side of the outer legs and the adjacent yoke for interleaving with a winding. The characteristic feature is that the width of the jointlessly connecting yoke is greater than that of the parted yoke, and that the width of the parted yoke and/or the width of the two outer legs is greater than half the center leg width.

Abstract: The invention concerns EI-type core laminations, especially for transformers. The E-piece has a center leg of width f, two outer legs of width b, a yoke of width c.sub.1 and two windows of width h and length e. The I-piece has the width c.sub.2. The laminations have the following ratios:e is greater than 3 f/2 and less than 3.5 f/2;c.sub.1 and b are both at least 1.1 f/2;c.sub.1 -c.sub.2 is at least 0.1 f/2;c.sub.1 +c.sub.2 is at least 2.1 f/2 and at most 2.5 f/2.A preferred embodiment of the invention has the ratios:e=3.25 f/2; c.sub.1 =b=1.25 f/2; c.sub.2 =h=f/2.

Abstract: Core laminations of the UI or EI type for iron cores, particularly for transformers, having two or three legs of equal length e and equal width f, spaced mutually apart by the same distance h, wherein the width c.sub.1 of the jointlessly connecting yoke is greater than the width c.sub.2 of the parted yoke, using the following dimensions: 1.1f.ltoreq.c.sub.1 .ltoreq.2.1f and 1.0f.ltoreq.c.sub.2 .ltoreq.1.5f and 0.1f.ltoreq.c.sub.1 -c.sub.2 .ltoreq.0.6f. Preferred dimensions for a waste-free UI shape and a suitable EI shape are: c.sub.1 =1.4f; c.sub.2 =h=1.2f; e=3.2f. Preferred dimensions for a waste-free EI shape are: c.sub.1 =1.5f; c.sub.2 =h=1.2f; e=2.7f.

Abstract: The invention concerns a transformer lamination having a center leg, two outer legs and two yokes connecting these legs and having at least one joint between one side of the center leg and the adjacent yoke. The characteristic feature is that the width of the jointlessly connecting yoke is greater than that of the parted yoke. In a preferred embodiment the sum of both yoke widths is roughly 1.35 times the center leg width.

Abstract: The invention concerns a transformer lamination having a center leg, two outer legs and two yokes connecting these legs and having at least one joint between one side of the center leg and the adjacent yoke. Characteristic features are that the length of the joint at each side of the center axis is at least 0.75 times the center leg width and that the joint has at least one concave part and at least one convex part on at least one side of the center axis. A preferred embodiment contains two symmetrical joints, each of them comprising two sections which are parallel to the center axis and one section which is perpendicular to the center axis.