International Business Machines Corporation

Alan J Kirton

Donovan M Janssen

Leroy Rose

Robert M Murphy

William J Friehauf

James A Valent

William H Ashbee

Larry E Rittenhouse

Richard S Kilen

Michael E Nard

A flexible disk drive head access mechanism optimized for automated manufacture is disclosed. The mechanism is a complete subassembly. As such, the mechanism can be handled by a robot, as the mechanism is automatically mounted to the disk drive's main frame member. The mechanism comprises a stepping motor having a metal output pulley which is wrapped by a metal band. The middle of the band is welded to the motor's output pulley. The two free ends of the band are welded to a flexible, low-mass band tensioner. This tensioner is a thin, elongated member which includes a U-shaped portion which is operable to tension the band about the pulley. Attachment of the ends of the band to the tensioner not only tensions the band, but also operates to bend the tensioner slightly toward the pulley, thus causing the band to self-center itself in a 360.degree. wrap about the pulley. In this way, rotary to linear output from the mechanism is assured. The low mass of the tensioner insures that the band is not damaged as the motor is handled by the robot, leaving the band and its tensioner unsupported and free to move. A damping arm is welded to the tensioner and operates to damp vibration of the tensioner when the mechanism is at the far end of its head access stroke. In this way, read/write errors are minimized.

Disk drive head access mechanism

An apparatus and method are disclosed for positioning magnetic heads relative to the recording tracks of a recording medium such as a floppy disk having circular, concentric recording tracks formed thereon. The magnetic heads are mounted on a head carriage, and the head carriage is moved, in response to received command pulses, so that the heads are moved linearly, by step increments, along a radius of the floppy disk. The heads are thereby moved across the spaced tracks on the disk, with each incremental movement of the heads being a distance less than the distance between the tracks, and being, for example, one-half or one-fourth of the total distance between tracks. Acoustic noise due to head movement is minimized by moving the heads by increments less than the distance between the tracks, with such movement avoiding exciting the resonances of the head moving apparatus. The magnetic heads are initially moved at a rate known to avoid exciting the resonance and, during such initial movement, the rate of received command pulses is determined. If the received command pulse rate is within a predetermined range, and is a rate that will not excite resonance, continued movement of the head is at the rate of the received command pulses.

Magnetic head positioning apparatus and method

A flexible disk drive is disclosed that is optimized for automated manufacture. The critical elements of the disk drive are divided into two functional groups, one of which includes the elements for loading and unloading the disk cartridge and the other of which includes the elements for reading and writing on the flexible disk within the cartridge, with the elements of each group being precisely registered with respect to one another on separate frame members. The frame members are coarsely registered with respect to one another and snapped together, after separate assembly of at least most of the elements on the separate frame members has been completed, and fine position registration of the flexible disk to the spindle is thereafter achieved during each loading operation of a flexible disk into the assembly disk drive by collet centering and clamping the disk to the spindle. By this arrangement, automated methods of manufacture can be effectively carried out for assembly of each frame member as well as final assembly of the frame members.

Flexible disk drive optimized for automated manufacture

Two stage colleting is disclosed for a flexible disk drive. Precise registration of a floppy disk within a disk cartridge with respect to the spindle and recording head of a disk drive is achieved by first positioning the cartridge with respect to the collet, and then aligning the collet with respect to the spindle axis as the collet is moved toward the spindle. This two stage colleting is made possible by use of a collet shaft having two different diameters with the larger diameter being adjacent to the collet during positioning of the cartridge with respect to the collet and with the smaller diameter being adjacent to the collet to allow movement of the collet in a direction normal to the spindle axis during alignment of the collet with respect to the spindle axis.

Two stage colleting in a flexible disk drive

A torsional actuator is disclosed for loading and unloading a flexible disk drive. The actuator includes a torsion beam having a biasing arm and a plurality of actuating arms extending therefrom with the free ends of the actuating arms being separately engageable with different ones of the collet, pressure pad and recording head arm of the flexible disk drive. The arms of the actuator are configured to enable selective and sequential movement of the collet, pressure pad and/or recording head arm in one direction toward a disk within the drive to establish a loaded, or operational, position and in the opposite direction away from a disk within the drive to establish an unloaded, or disk accessing, position with such positioning being determined by a force applying cam engageable with the actuator.

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Boulder, CO, United States of America

Alan J Kirton