Patent ID: 8289031

Claim:
An apparatus for testing the quality of an electrical steel lamination, said lamination having a first end and a second end and having a first coating on a first surface and a second coating on a second surface, comprising: a) a stationary cylindrical spindle having an axis of rotation and a stationary electrical terminal, b) a rotatable cylindrical member having an electrically conductive compressible surface and concentrically mounted about said spindle axis, c) an integral sealed annulus containing liquid metal built into said rotatable cylindrical member to electrically connect said rotatable cylindrical member and said stationary electrical terminal, d) the length of said rotatable cylindrical member longer than the width of said electrical steel lamination, and e) the diameter of said rotatable cylindrical member and hence dead weight of said apparatus sized to apply a specified compressive pressure over said first coating on the electrical steel lamination.