International Business Machines Corporation

Havant International Limited

Xyratex Technology Limited

Anthony R Hearn

Michael R Hatchett

Graham N Dew

John S Heath

Charles M Lacey

Julian T Young

Michael W Hall

John R Reidenbach

Michael George Taylor

Clarence R Schwieters

Robert Duncan Commander

Anthony W Leonard

Peter J Elliott

George A Cunningham

Hugh G Dickie

Thaddeus L Larek

David J Sebborn

David R Farquhar

Robert N Evans

Graham Collins

David J Orriss

Colin Presly

A low speed moving magnet motor ( ) has a moving magnet ( ) and a stationary coil ( ) for carrying an electric current and disposed in relation to the moving magnet ( ) such that a magnetic field generated when a current flows through the coil ( ) causes the moving magnet ( ) to move relative to the coil. A magnetic return path member ( ) is fixed in relation to the coil ( ) to provide a return path for a magnetic field generated by the coil ( ) and the moving magnet ( ). In an example, the magnetic return path member ( ) is free of insulating laminations. The moving magnet ( ) is mounted on a rotor ( ) of the motor ( ) which has a high inertia.

Low speed moving magnet motor having a high inertia rotor

A vibration damping system is provided for damping vibrations in an apparatus (,). The damping system is particularly useful in a servowriter (,). The damping system has resilient means (,) for supporting at least the majority of the weight of the apparatus (,). The resilient means (,) has a first spring rate. The damping system has damping means (,) for damping vibrations of the apparatus (,). The damping means (,) has an effective second spring rate. The ratio of the first spring rate to the effective second spring rate is r:1 where r<1.

Vibration damping system and servowriter

A tool (,) is provided for mounting in and testing a fixture (,) used for mounting a device, such as a disk drive, having an arm which is movable to selected locations by an actuator. The tool has a movable member (,) which is movable to mimic movement of an arm of such a device mounted in the fixture (,). Movement of the tool (,) in the fixture (,) as a reaction to movement of the movable member (,) is measured and compared with a standard to enable the fixture to be passed or failed.

Tool, apparatus and method of testing a fixture

A mounting for a disk file comprises a carrier defining a space into which the disk file can be removably inserted for operational use. The carrier has a base and two opposed sides and, and first and second wedges and which are movable to act between the main body of the disk file and the side of the carrier, to secure the disk file against movement relative to the carrier. The wedges include wedges which are movable in a vertical direction by a control linkage operated automatically when the disk file is inserted into the carrier structure.

Disk file mounting

Shaft mounting for a disk file

A disk file includes multiple disk surfaces, on which servo information is recorded, with an offset in azimuth from one disk surface to another. Each head comprises a magnetoresistive stripe for reading and an inductive write coil. The servo system reads servo information from each disk in turn, multiplexing the signals from each disk together to form a single position error signal (PES). The separation of the servo multiplexer, attached to the MR stripes, from the write multiplexer, attached to the inductive coils, avoids problems due to contamination of the servo signal by the write signal. A least squares fit is used to generate the PES from the series of servo samples from each disk surface.

Disk file with multiplexed servo system

Disk file having thermal expansion ring for ensuring disk/hub

Method of assembling a disk file

Voice coil actuator with resiliently mounted shorted turn

A disk file comprises a head disk enclosure 1 connected to a support frame by a plurality of isolation mounts. Each isolation mount comprises a constrained layer flexure 23 which is rigidly attached at both ends to a bracket 25 of the support frame. Located in an aperture in the constrained layer flexure is a resilient grommet 24. This grommet supports a bolt 27 which passes through the grommet and into the head-disk enclosure casting.

Disk file with isolation mount

A linear actuator for positioning the heads of a disk file relative to tracks on the disks employs a ceramic material having wear properties superior to steel in guide surfaces for guiding a head supporting carriage running on rotary bearings in contact with the guide surfaces. The preferred ceramic material is tetragonally stabilized zirconia.

Linear actuator with reduced wear guide way

A cantilever magnetic head support arm assembly for a disk file comprises a flat beam structure and a means of damping the structure against out-of-plane vibrations. The damping means comprises a rigid sidebar extending along one longitudinal edge of the beam structure and a layer of compliant damping material connecting the beam structure and sidebar together. Relative motion between the beam structure and sidebar causes elastic shear deformation of the damping layer to absorb the energy of vibration.

Magnetic head arm assembly

An electric rotary actuator for producing rotation through a limited angle comprises a rotor winding made of a plurality of thin loop coils arranged in a continuous cylindrical framework as part of a rotor shell. The rotor shell lies in an annular flux gap defined by a stator magnet assembly and a flux return means. Each pair of adjacent axially extending limbs of adjacent loop coils lies opposite to and cooperates with a respective stator pole face. This winding arrangement helps to optimize the torsional resonance characteristics of the rotating mass.

Limited angle electric rotary actuator

Growing community of inventors

South Wonston, United Kingdom

Anthony R Hearn