International Business Machines Corporation

Ralph D Brower

Neil L Robinson

A head is moved toward and rotated against an abrasive while its resistance is monitored by a four-lead bridge. Prior to final manufacture, the head includes a highly conductive segment which surrounds the active head element on three sides and is electrically connected to it at one point. The segment is ground away during manufacture. Two leads from the head are connected to two slip rings, and each slip ring has two pairs of brushes, each wire from the bridge going to a different brush pair. Head movement toward the abrasive is terminated when a predetermined head resistance is detected by the bridge.

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Longmont, CO, United States of America

Ralph D Brower