Abstract: A latching method and a latch for a voice coil motor in a disc drive. The latch has a hub and a latch surface. The latch surface has a rotational latching range in which the latch surface latches the voice coil motor. A first magnetic detent is coupled to the hub and is active when the latch surface is in a first rotational segment in the latching range. A second magnetic detent couples to the hub and is active when the latch surface is in an offset second rotational segment in the latching range. The offset shapes detent torque over the latching range.

Abstract: A compressive limit stop for limiting travel of an actuator assembly of a data storage device is disclosed. The compressive limit stop separates a first pole piece from a second pole piece of the data storage device, each pole piece adjacent the actuator assembly, the compressive limit stop comprising a rigid body with a top flange adjacent the second pole piece and a bottom flange adjacent the first pole piece, an inner portion having a diameter less than the diameter of the top flange disposed between the top and bottom flanges forming a channel between the flanges and a compressive sleeve with an inner wall adjacent each flange while enclosing the channel to form a gap between the inner portion and the inner wall. The compressive sleeve deflects and compresses between the actuator assembly and the inner portion to decelerate movement of the actuator assembly.

Abstract: A pivot bearing cartridge for an actuator in a disc storage system includes a shaft, a first outer sleeve and a second outer sleeve. The first and second outer sleeves are coupled together. Raceways are formed in the sleeves and the shaft. The raceways carry balls to form ball bearings allowing movement of the sleeves relative to the shaft.

Abstract: A tolerance ring which provides a low consistent installation force profile as a rotatable member, such as a disc drive actuator, is installed onto a stationary member, such as a shaft extending along an axis. The tolerance ring has a substantially cylindrical base portion from which a plurality of spaced apart raised portions radially extend. Each raised portion has a contact surface with a substantially elliptical cross-sectional shape in a direction parallel to the axis and a pair of transition portions between the contact surface and the base portion. Each transition portion further has a continually radiused cross-sectional shape in a direction parallel to the axis so that, for each raised portion, a selected one of the elliptical cross-sectional shapes and the pair of radiused cross-sectional shapes is convex with respect to the axis and the remaining one of the elliptical cross-sectional shapes and the pair of radiused cross-sectional shapes is concave with respect to the axis.

Abstract: A stop and a disc drive with a stop are provided that limit rotation of a rotary actuator, which moves laterally between an upper magnet bonded to an upper plate and a lower magnet bonded to a lower plate. The stop includes a spacer core that has an upper portion for contacting the upper plate, a lower portion for contacting the lower plate, and a middle portion having a recessed surface. A stop sleeve is press fit to an upper press-fit surface on the upper portion and a lower press-fit surface on the lower portion. The stop sleeve and the recessed surface together define a deflection space.

Abstract: A tolerance ring is disclosed which provides increased hoop strength and resistance to deformation. The tolerance ring is placed on a stationary post so as to circumferentially extend about an outer surface of the post. An actuator assembly with an inner bored recess is thereafter placed onto the post so that the tolerance ring is compressed between the surface of the inner bored recess and the outer surface of the post, thereby maintaining a desired nominal position of the actuator assembly about the actuator pivot axis. The mechanical configuration of the tolerance ring includes a substantially cylindrical base portion from which at least one brace portion and a plurality of contact portions project. The brace portion preferably extends along the circumference of the base portion and preferably comprises either a circumferentially extending ridge or flange.

Abstract: An apparatus for reducing manufacturing cost and increasing disc drive actuator assembly stiffness. A post extends from a base deck and supports an actuator assembly and cartridge bearing. In particular, the cartridge bearing comprises a stationary shaft, a bearing supported by the shaft, and a sleeve rotatably supported by the bearing for rotation about the stationary shaft. A first tolerance ring is disposed between an inner surface of the shaft and the post to secure the cartridge bearing in place during assembly. A second tolerance ring is interposed between the cartridge bearing and the E-block to secure the E-block.

Abstract: A method of reducing debris within an E-block of an actuator assembly in a disc drive is provided. A manufactured E-block is first provided for tooling. The E-block has a central bore with an inner diameter and a bore surface. A hardening member is then provided with an outer diameter that is larger than the inner diameter of the bore surface. The hardening member is pressed through the central bore so that the hardening member compresses and deforms the bore surface. As the hardening member deforms the bore surface, the bore surface becomes substantially smooth and hard.

Abstract: An improved pivot mechanism for a disc drive actuator assembly, the actuator assembly having an E-block which supports an array of read/write heads in reading and writing data relationship to a plurality of data discs, the actuator assembly having a bearing cartridge that rotatably supports the E-block and is receivingly disposed within a bore of the E-block and fixed therein by a tolerance ring interposed in the bore between the bearing cartridge and the E-block. The bearing cartridge has a hollow sleeve that supports the tolerance ring on an outer diameter thereof, and furthermore supports a damping member on the inner diameter thereof. The damping member is attached to the sleeve by a selected damping material.

Abstract: A latch for a disc drive, wherein the disc drive has an actuator that is pivotally supported for moving an array of read/write heads radially across a data storage disc between a parked location and a data storage location, the parked location providing a landing surface for the read/write heads when the disc drive is non-operational, the latch limiting the actuator from pivoting so that the read/write heads remain in the parked location while the disc drive is non-operational. The latch has a base member enabling attachment to the disc drive, the base supporting an inner stop and an outer stop which limit the actuator rotation, the base further supporting a cantilevered latch arm which biases a latch finger to a position whereat the latch finger and the inner stop form a latching groove and the latch finger and the outer stop form an unlatching groove, the actuator being confined by the latching groove in the latched mode and being confined by the unlatching groove in the unlatched mode.

Abstract: An improved crash stop apparatus having an inner crash stop that pressingly engages the actuator assembly of a disc drive when the read/write heads of the actuator assembly approach a desired inner extent of radial travel to prevent further movement of the read/write head beyond the inner extent of travel and furthermore having an outer crash stop that pressingly engages the actuator assembly when the read/write heads approach a desired outer extent of radial travel. The crash stops each have a pin rigidly mounted at a proximal end and having a cantilevered distal portion which is disposed in the path of travel of the actuator. An elastomeric member is disposed between the impacting actuator and the pin. The elastomeric member and cantilevered pin provide a two-stage braking impulse to decelerate the actuator, wherein the first stage compresses the elastomeric member and wherein the second stage deflects the cantilevered pin.

Abstract: In a computer disc drive system having a plurality of voice coil motors for independently actuating a plurality of actuator arms or E-blocks, a single voice coil motor servo control circuit controls the plurality of voice coil motors. In a preferred embodiment, a single digital servo processor dynamically allocates servo bandwidth to the plurality of voice coil motors according to the present activity of each voice coil motor. In a preferred embodiment, the single digital servo processor allocates the greatest amount of bandwidth to a voice coil motor that is presently positioning an associated read/write head for writing, a lesser amount of bandwidth to a voice coil motor that is presently positioning a read/write head for reading, and the least amount of bandwidth to a voice coil motor that is presently seeking or idle.

Abstract: A latch for a disc drive wherein the disc drive has an actuator that is rotatably supported for moving an array of read/write heads radially across a data storage disc between a parked location and a data storage location, the parked location providing a landing surface for the read/write heads when the disc drive is non-operational, the latch preventing the actuator from rotating so that the read/write heads remain in the parked location while the disc drive is non-operational. The disc drive has a voice coil motor for moving the actuator, the voice coil motor including a magnet assembly having a pair of opposed magnet members supported by opposing poles. The latch is interposed between the poles, having a base member that pivotally supports a latch pawl between a latched and an unlatched mode. A latch pole is magnetically supported by the poles to urge the latch pawl to the desired mode.

Abstract: An improved attachment of an actuator E-block of an actuator assembly to a pivot bearing assembly for a disc drive, the E-block having a central bore having a pair of alignment edges to pressingly engage a cartridge bearing of the pivot shaft bearing assembly, and the cartridge bearing supporting a canted coil spring within a peripheral groove so that the spring is interposed between the cartridge bearing and the E-block within the E-block bore. One or more fasteners extend through the wall of the E-block adjacent the alignment edges to pressingly engage the cartridge bearing against the alignment edges, the canted coil spring filling the clearance gap between the cartridge bearing and the E-block bore to provide a resilient support to the E-block.

Abstract: A method for fabricating a dual actuator assembly for a disc drive. The dual actuator assembly has first and second rotatable actuator assemblies which are axially aligned for independent rotation about a common axis and support at least first and second read/write heads, respectively. The method comprises providing a dual bearing cartridge assembly with a stationary shaft aligned along the common axis having first and second ends, a first rotatable sleeve mounted for rotation about the stationary shaft toward the first end, a second rotatable sleeve mounted for rotation about the stationary shaft toward the second end, and first and second bearing assemblies supporting the first and second rotatable sleeves, respectively.

Abstract: A skinned, foam core E-block assembly for a disk system for supporting a plurality of head arrays to write data to and/or retrieve data from tracks of a media disk. The E-block assembly is formed of a foam core material with a non-porous stressed skin that matches or exceeds the performance of currently used materials, at a lower cost. The foam may be ceramic, metallic, or polymeric. The skin is non-porous and may also be ceramic, metallic, or polymeric.

Abstract: A lubricant reservoir for a vapor transport type rigid magnetic disk drive lubricant system includes a metal heat sink that presents a finned surface at the side exposed to the outside environment. A second surface within the sealed head-disk enclosure cooperates with a thermal heat transfer resisting wall portion to form a duct. A lubricant reservoir is retained against the heat sink surface within the duct. The reservoir assembly is secured to the head-disk enclosure wall by mounting tape that not only seals the enclosure, but thermally isolates the reservoir assembly from the enclosure wall.

Abstract: A structure and organization for a magnetic disk drive provides for optimizing the volumetric storage density within a device form factor by optimizing the number of disks. The spindle and dual rotary actuators are respectively supported at each side by a pair of support plates that are separated and supported by not only the spindle and actuator shafts, but also the voice coil motor core pieces and tie plates which carry shock mounts. This head-disk assembly is shock mounted in the lower part of a two part enclosure wherein the enclosure parts are aligned and separated by elastomer guides and the separation covered by a compliant tape to complete the enclosure. Both actuators use a common servo surface while one actuator carries upwardly facing transducers and the other downwardly facing transducers so that each arm extending between disks mounts, but a single suspension-transducer assembly to reduce interdisk spacing.

Abstract: The magnetic disk drive chemical breather filter of the present invention affords protection with respect to chemical vapors and gases in addition to trapping particulate pollutants. The chemical filter as described, protects against both organic vapors and inorganic gases. In addition particulate filters are interposed between the chemical filters and both the exterior atmosphere and internal atmosphere. The combined filter is isolated from both external and internal atmosphere by extended length diffusion passages. Both difffusion passages are composed of multiple parallel paths to prevent the blockage of any single path from impairing the functioning of the filter. Chambers formed at each side of the combined filter medium and access thereto by the diffusion passages at the center of one chamber and the periphery of the other enables the length of the air passage through the filter medium to be equal irrespective of the portion of the filter through which the air flow passes.