International Business Machines Corporation

Thomas Donald Weller

Eric Alan Eckberg

Gerald Daniel Malagrino, Jr

Brian Lee Rappel

George M Moorefield, Ii

John Patrick Hagen

Terry Fredrick Banitt

Roger Willard Johnson

Carl Francis Sermon

A lapping plate topography system includes a measuring apparatus for measuring the surface of a lapping plate, and an analysis apparatus for analyzing and presenting the data resulting from such measurements. The measurement apparatus has a non-contacting capacitive probe for measuring a height of the surface of the lapping plate, a rotary arm assembly for moving the probe in an arc over the surface of the lapping plate, and a spindle assembly for rotating the lapping plate about its center. The computer-based analysis apparatus is operable to input from the measurement apparatus the measured height at a plurality of data points on the surface of the lapping plate, calculate Fourier transform harmonic coefficients based on the plurality of measured heights, calculate surface ripple coefficients based on the calculated Fourier transform harmonic coefficients, and output the calculated surface ripple coefficients to an appropriate display device.

Lapping plate topography system

A tape drive which may accommodate tapes having a servo control track thereon as well as tapes without such tracks advantageously uses a lockout to prevent unwanted head translation when operating in an open loop mode. The lockout may be accomplished by energizing a voice coil motor to fix the head position, driving the voice coil motor to a fixed stop positioning the head, or latching a rocker connected to the head, thereby preventing movement of the head. The latching/unlatching function may be accomplished by driving an actuator supporting the beam springs, head and latch to an end-of-track position to similarly unlatch the rocker and return the assembly to a servo controlled mode of operation.

Head locking apparatus in a servo system so that the head can read and

A tape drive is fabricated with a chassis and a bridge. The bridge acts to support the read/write head actuator and to also define the datum surfaces for locating a mating magnetic tape cartridge. The bridge is manufactured of materials which are highly rigid and stable dimensionally. The chassis of the tape drive is fabricated from materials such as plastics which are relatively flexible and do not have the rigidity of that characterized by the bridge. The more flexible chassis of the tape drive permits the isolation of distortions and distortionary forces in the chassis and does not transmit those forces and distortions to the bridge. The effect of the two piece arrangement is that the pieces may be made relatively inexpensively and retain reliability of much more expensive materials in manufacturing processes herefore considered necessary. The electronic circuits associated with and part of the tape drive may be protected by fabricating the bridge of an electrically conductive material and grounding it to insure that the chances for electromagnetic and electrostatic discharge are minimized.

Mechanical device enclosure for high performance tape drive

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Rochester, MN, United States of America

Thomas Donald Weller