摘要 |
A U-shaped ferro-magnetic pole frame has a circular recess formed in the closed end thereof with a plurality of peripherally spaced raised lugs formed in the recess. A tubular ferro-magnetic pole piece, adapted for insertion into an electrical coil, has one end thereof clamped temporarily against the lugs and current is passed therethrough for effecting resistance welding of the pole piece to the pole frame and the clamp is then removed.
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