Abstract: A limit stop filter support apparatus for use in controlling fluidic currents and limiting movement of an actuator within a housing, such as in a data storage device. First and second filter retention members extend from a filter support base to confine opposing ends of a filter used to filter fluidic currents within the housing, and a cantilevered limit stop extends from the base to contactingly limit movement of an actuator moveable within the housing. The limit stop preferably comprises a spring member supporting a latch member, the latch member selectively confining the actuator in a parked position. The first and second retention members each preferably include a shroud surface adjacent an outer peripheral edge of a rotatable storage medium to direct the fluidic currents established by rotation of the medium.

Abstract: The present invention reduces the time required for coefficient convergence and thus improves time-to-ready. To that end, the present invention provides an initial learn—preferably non-zero—coefficient. The initial learn coefficient is based on a translation of timing information to position information. One aspect of the present invention uses address marks of a disc then translates them to phase position information. The present invention measures the times between address marks of adjacent servo sectors. Variations between those times is related is related to disc runout, particularly disc eccentricity. Also, the servo sectors are used to identify at which phase the maximum amplitude (or magnitude) of the timing variations occur. This phase information and maximum amplitude are used as variables in determining the initial learn coefficient. The present invention also utilizes a plant model to predetermine a variable.

Abstract: True random numbers are generated from position error signals or like signals. The generator is not dependent on a potentially biased reference or threshold, and is capable of quickly generating true random numbers on demand. The present invention can be implemented as an integral functionality of a data storage device to control access to data stored in the data storage device. It can also be implemented in data storage devices for controlling access to host systems or host devices associated with the data storage devices.

Abstract: An apparatus for use in attaching a head gimbal assembly (HGA) onto an actuator arm of an actuator assembly during an HGA installation process. The apparatus includes, a central body portion with a base support surface; and a pair of support arms extending from the central body portion forming a channel sized to accommodate expansion of an attachment aperture of an actuator arm during the installation process. Each support arm includes, a first and second support surface offset from and parallel to the base support surface. A first support arm thickness is formed between the first support surface and the base support surface, while a second support arm thickness is formed between the second support surface and the base support having a thickness less than the first support arm thickness. Each support arm thickness supports a corresponding HGA adjacent actuator arm during the installation process.

Abstract: An end stop assembly for limiting the travel of an actuator in a disc drive, the actuator pivotally supported by an enclosure for movement of a read/write head in data reading and writing relationship to a data disc. The end stop assembly comprises a base plate fixedly positioned within the enclosure, a post extending upward from the base plate and a cantilevered arm extending outward from the post. The arm comprises a proximal end connecting the arm to the post and a distal end for providing contacting engagement with the actuator. Furthermore, the cantilevered arm is displaceable in a rotational direction substantially about the post and deformable in a direction substantially along its longitudinal axis.

Abstract: An actuator arm bumper for dampening contact between a surface of an actuator arm and a surface of a disc in a disc drive. The actuator arm bumper comprises a non-marring, non-particulating and durable material such as polycarbonate which extends through and beyond the cross-sectional thickness of the actuator arm. The actuator arm bumper is formed from a sphere or rod of polycarbonate material which is placed into an opening of the actuator arm and deformed using a heat staking or crimping operation. A ramp loading installation tool is also used to simultaneously form all of the actuator arm bumpers in the actuator arms of the disc drive.

Abstract: In one aspect, the present invention provides a solution for neutralizing the acid occurring in acidic beverages such as coffee, tea, wine and other alcoholic beverages, etc. The solution of the present invention provides a concentrated hydroxide solution which can be added dropwise to beverages to neutralize the acid content. By neutralizing the acid in such acidic beverages, the solution of the present invention improves the taste characteristics of such beverages. In another aspect, the solution provides a proper balance of body electrolytes to ensure that the body's system remains in balance. These electrolytes are balanced to match the concentration ratios of the electrolytes contained in the intercellular fluid. The solution prepared in this manner can be stored in conveniently sized dropper bottles so that the beverage additive can be carried in a pocket, purse or the like.

Abstract: Method and apparatus for compensating for errors in the location of servo frames in a disc drive, the servo frames providing control inputs to a servo loop of the disc drive. Each servo frame includes an additional compensation field to which a compensation term is written, the compensation term indicative of the average radial error in the location of the servo frame. The compensation term is determined by measuring the radial distance between adjacent servo frames over a plurality of revolutions of the disc and averaging these measured radial distances. The compensation terms are thereafter used in conjunction with position information from the servo frames to control the position of the head. The compensation term facilitates the elimination of repeatable, random errors in the locations of the servo frames, causing the head to nominally follow a circular path about the disc, regardless of the errors in the locations of the servo frames.

Abstract: A low particulating circuit board for a disc drive flex assembly, and a method for forming the same, are disclosed. The circuit board comprises a conductive metal substrate which has sufficient thickness to provide mechanical support and backplane suppression for the circuit board and to efficiently sink heat generated by preamplifier circuitry housed by the circuit board. The substrate has dielectric layers formed on the top and bottom surfaces thereof, the dielectric layers comprising an epoxy interleaved with nonparticulating fibers, such as tetrafluorethylene (TFE) fibers. Traces and pads are provided on the dielectric layers to provide the necessary electrical connections for the preamplifier circuitry. A plurality of circuit boards are formed from a panel and subsequently cut therefrom. Particulate generation is minimized through the use of the metal substrate, as well as recession of the substrate and the solder masks to reduce the amount of material cut during the cutting operation.

Abstract: Apparatus for clamping a plurality of axially spaced, rotatable elements such as a stack of actuator arms or magnetic storage discs in a disc drive. The rotatable elements are coupled to respective housings for rotation at a respective radius about associated, stationary shafts by bearing assemblies. As used in an actuator assembly, an actuator shaft bearing housing is inserted into an opening in each of the actuator arms and a clamp fastener exerts a clamping force on the actuator arms so as to secure the actuator arms relative to the actuator shaft bearing housing. The clamp fastener comprises a clamp fastener cylinder with an exterior surface which is fixably attached to a corresponding interior surface of the actuator shaft bearing housing. The clamping force is exerted by a clamp disc protruding in a radial direction from the clamp fastener cylinder, beyond the radius of the actuator shaft bearing housing.

Abstract: Apparatus for protecting a disc drive from damage due to non-operational mechanical shocks, the disc drive comprising a rotatable disc having an inner radius and an outer radius and a controllably rotatable actuator adjacent the disc. A snubber is provided adjacent the disc, the snubber having a body portion rigidly affixed with respect to the disc and snubber arms connected to the body portion. The snubber arms extend from the body portion towards the disc and above and below the elevation of the disc, with each snubber arm having a distal end located at a position adjacent the disc between the inner and the outer radii of the disc and towards the outer radius of the disc. The height of each snubber arm limits deflection of the disc at the outer radius of the disc as a result of mechanical shock forced supplied to the disc drive assembly.

Abstract: A flexible manufacturing press assembly for the processing of sheet material through punching and forming operations having a plurality of tool assemblies of which each, in turn, group and support a plurality of processing tools. Each tool assembly has a punch magazine, a die block, and a stripper plate for processing the sheet material in the manner of a Class A die. A sheet material positioning assembly clamps the sheet material and positions it within a two-axis plane adjacent the tool assemblies. A punching head assembly, supported by the sheet material positioning assembly, positions a punching head adjacent the grouped tool supports.

Abstract: A method for following a selected data track on a selected data surface of a disc drive of the type having a dedicated servo system in which guiding of data heads to follow data tracks on data surfaces is effected by positioning an actuator upon which the data heads are mounted in relation to the location of a servo head, also mounted on the actuator, with respect to servo tracks on a dedicated servo surface. The data tracks are organized into cylinders, each containing a servo track, and a selected data track is accessed by seeking to an optimum servo track displaced from the servo track in the cylinder containing the data track by an integral number of track spacings selected to compensate for misalignments greater than a track spacing between the data and servo heads. Data track following is then effected by offsetting the servo head from the optimum servo track to compensate for misalignments of less than a track spacing between the data and servo heads and tracks.

Abstract: A low sway space disc drive assembly having a base deck with a base portion and side walls extending therefrom. A top cover mates with the side walls to form an internally sealed environment for the disc drive. An external chassis is mounted to the underside of the base portion of the base deck and a vibro-acoustic isolator is disposed between the external chassis and the base portion, the isolator and the chassis providing mechanical isolation for the drive from internal and external vibrations as well as strengthening the base deck. The chassis includes flanges which strengthen the chassis and accommodate a printed circuit board attached to the base deck, the printed circuit board providing the control electronics for the drive. The flanges further include threaded holes for attachment of the chassis to a user environment.

Abstract: Method and apparatus for dynamically compensating for servo burst measurement offsets in a disc drive. A first type of servo position error signal is used during a compensation routine to position a head adjacent a selected track on a disc, the first type of servo position error signal determined from servo burst signals read by the head from servo position fields on the disc. A second type of servo position error signal is also generated from the servo burst signals and the difference between selected values of the second type of servo position error signal is compared to an acceptance limit. Compensation terms are incrementally added to the servo burst signals used to generate the second type of servo position error signal until the difference is below the acceptance limits. Thereafter, the compensation terms are stored and retrieved during normal track following operations to generate a compensated servo position error signal.