Two-part transformer lamination of slidingly engageable parts

Claim 1

A two part transformer lamination of which the two parts are slidingly and interlockingly engageable to form a lamination having two base limbs and at least two other limbs extending between the base limbs, the two outer limbs of said other limbs each having a straight outer edge, wherein the two parts are shaped to define together at least two locking means, one of each being located in one of said outer limbs and comprising a tongue on one of said parts and a complementary shaped closely fitting portion on the other of said parts, of which the tongue has a first edge at the tip thereof disposed at an oblique angle to the straight outer edge of the respective outer limb, and a second edge parallel to and longitudinally spaced from the first edge, the second edge being offset outwardly from said first edge, said first and second edge being connected by a third edge disposed at an obtuse angle to the first and second edges respectively, the distance from the junction of the first and third edges to the straight outer edge of the respective outer limb being greater than that from the junction of the second and third edges to the same straight outer edge.