Abstract: A system for measuring transient friction of a head-disk interface in a magnetic disk storage device employs a servo system for accurate measurements. A first movable member carries a slider simulating a magnetic head which rests on a disk when said disk is at rest. The movable member is movably mounted to a second fixed member. A frictionless detector detects a displacement of the movable member relative to a position of the fixed member produced by a force due to friction when the disk spins. A servo system maintains a fixed distance between first and second members in response to an output from the detector and moves the movable member in response thereto. The output is taken from the servo system and provides a signal proportional a force due to friction exerted on said movable member.

Abstract: A heddle frame which has a pair of rectangular hollow metal cross rails, a pair of heddle bars associated with the cross rails for supporting heddles and a pair of end braces connected to said cross rails and said heddle bars and two or more connections between the cross rails and the heddle bars intermediate the end braces. The connections between the heddle bars and the cross rails comprise a hanger which may be formed of a synthetic polymeric material which is rigid, has a first portion which extends into an opening in the bottom of the hollow cross rail, and a second portion which is attached to the heddle bar. The upper portion of the hanger has a closed rectangular opening extending through it into which is fitted a metal insert of substantially the same thickness as the upper portion of the hanger.