Abstract: An apparatus for changing the mechanical response characteristics of an actuator arm in a disc drive such that damage to the disc drive resulting from mechanical shock is prevented or minimized. An actuator arm is provided with a lightening hole in which is supported a stiffening arm mass damper and a retaining filler. The stiffening arm mass damper can be made of a stiffening material or a damping material as desired, such as a metallic cylindrical member, to change the mechanical response characteristics of the actuator arm to reduce contact between the actuator arm and the disc surface resulting from mechanical shock to the disc drive. The filler is preferably a moldable elastomeric material that substantially encapsulates the stiffening arm mass damper within the lightening hole.

Abstract: An apparatus is disclosed for reducing disc deflection in response to the application of a non-operational mechanical shock to a disc drive. The disc drive comprises discs rotatable about a disc axis and each having an outer diameter. A circumferentially extending snubber is provided proximate a substantial portion of the outer diameter of each of the discs. The snubber includes a shroud portion immediately proximate the outer diameter of each disc and snubber arms which extend from the shroud portion in a direction toward the disc axis. The snubber limits deflection of the outer diameter of each disc in response to the application of a nonoperational mechanical shock to the disc drive.

Abstract: A ramp loading apparatus for a disc drive having a disc with a data recording surface and a controllably moveable actuator arm supporting a read/write head adjacent the data recording surface, the ramp loading apparatus having a body forming a loading ramp and a ramp stiffener attached thereto. The body has a loading tab channel associated with the lift ramp so that the read/write head can be lifted from the data recording surface of the disc during its non-operating mode. Radially extending disc snubbers extend over the outer perimeter of the disc to reduce deflection of the disc caused by the application of mechanical shock to the disc drive.

Abstract: An apparatus and method for removing baseline shift in low frequency readback signals of a disc drive, such signals characterized by peaks separated by baseline portions. The disc drive comprises a head controllably positionable adjacent tracks on a rotatable disc, a servo circuit which controls the position of the head in response to the readback signals and an adjustable filter operably connected to and serially disposed between the head and the servo circuit. When baseline shift is detected in the baseline portions of the readback signals at a predetermined margin threshold, the response characteristics of the adjustable filter are adjusted to remove the detected baseline shift from the readback signals.

Abstract: A connector contact assembly for receiving insertion of a corresponding connector pin to establish an interconnected electrically conductive path is disclosed suitable for use, for example, to provide drive current to a spindle motor of a disc drive. The connector contact assembly comprises a rigid, nonconductive housing and an electrically conductive contact which pressingly engages the connector pin when the connector pin is inserted along a pin insertion axis. The contact comprises a contact base rigidly secured to a first surface of the housing, a central flexure extending from the contact base along a curvilinear path apart from the first surface, and a distal end rigidly secured to a second surface of the housing. When the connector pin is inserted, the central flexure is deflected toward the first surface, with the second surface limiting movement of the distal end in a direction parallel to the pin insertion axis.

Abstract: An apparatus and method are disclosed for improving servo performance of a disc drive. The disc drive includes a head adjacent a rotatable disc on which data are stored on a plurality of tracks. A servo circuit is provided to control the position of the head by generating an actual (raw) position error signal (PES) nominally characterized as nonlinear over a portion of the width of a selected track and indicative of position of the head relative to the selected track. The servo circuit further generates a predicted PES as an approximation of the actual PES, and then controls head position through summation of the actual PES with the predicted PES. The servo circuit includes a burst signal generator which generates predicted burst signals as approximations of actual burst signals determined from readback signals from the head as the head reads servo burst patterns on the disc.

Abstract: An apparatus and method for detecting rotational vibration applied to a disc drive having a rotary actuator adjacent a rotatable disc. The actuator supports a head adjacent a recording surface of the disc and an actuator coil in a magnetic field of a magnetic circuit of a voice coil motor. A second, velocity sense coil is further coupled to the actuator and immersed in the magnetic field of the magnetic circuit, with the velocity sense coil being electrically isolated from the actuator coil. Rotational vibration is detected in relation to a sense voltage induced across the velocity sense coil as the magnetic circuit is moved relative to the velocity sense coil. A data transfer operation between the head and a host device is interrupted when the magnitude of the rotational vibration exceeds a specified magnitude.

Abstract: A method and apparatus for providing a relatively large, multi-chamber fluid buffer between the interior of the drive and the surrounding external environment. The large fluid buffer is provided by a plurality of channels and chambers stamped into the cover of the disk drive, through which channels and chambers fluid must diffuse in order to enter or exit the drive.

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: 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: An apparatus and associated method are disclosed for storing servo information on a rotatable disc of a disc drive at a frequency that varies for each track defined on the disc. A servo track writing system is provided which generates a fixed frequency pattern clock signal that indicates the appropriate angular locations on the disc at which the servo information is to be written, and a servo write clock signal having a selectively variable frequency at which the servo information is written. A reset pulse temporarily suspends and restarts the servo write clock signal so as to be in phase with the pattern clock signal at the initiation of the output of the servo information.

Abstract: A peripherally extending acoustic compliance area in a disc drive housing which reduces emission of acoustic noise by the disc drive. The housing includes first and second plates and side walls which cooperate to form an enclosure for an excitation source disposed within the housing. At least a selected one of the plates has a contact point to which the excitation source is mechanically coupled, a first portion of the selected plate surrounding the contact point and a second portion thereof disposed between the first portion and an outer perimeter of the selected plate, with the second portion having an increased compliance with respect to the first portion. The increased compliance can be formed by reducing the thickness of the second portion. Damping material can be additionally supported by the second portion to provide further acoustic noise reduction.

Abstract: Apparatus and method for writing servo information in a head disc assembly (HDA) comprising a head, a disc and a spindle motor for rotating the disc. The servo information is written by the head to servo fields on the disc. A positioning system positions the head relative to the disc and a control circuit controls the positioning of the positioning system as well as the rotational speed of the spindle motor. An electro-mechanical transducer outputs a signal indicative of vibratory response of the HDA as the disc is rotated and a computer is provided which instructs the control circuit to rotate the spindle motor at each of a plurality of rotational speeds while characterizing the vibratory response of the HDA using the signal from the transducer for each of the rotational speeds. An optimal rotational speed is thereafter selected and used to write the servo information, the optimal rotational speed minimizing variation in the placement of the servo information.

Abstract: A method and apparatus are disclosed for optimizing operational performance of a disc drive through temperature dependent parametric configuration. A plurality of parameter sets corresponding to a plurality of predefined contiguous operational temperature ranges of the disc drive are initially established. During operation of the disc drive, a temperature sensor is used to periodically measure the temperature of the drive. The operational temperature range in which the measured temperature falls is identified, and the disc drive utilizes the parameter set corresponding to the identified operational temperature range.

Abstract: A low sway space isolation chassis adapter is disclosed to facilitate the mounting of a disc drive in a mounting environment, the disc drive having a base deck to which a printed circuit board is affixed. A mounting plate is secured to mounting features of the base deck so that the printed circuit board is disposed between the mounting plate and the base deck. The mounting plate includes a central web to which a damping layer is affixed. A chassis plate is disposed between the mounting plate and the printed circuit board, the chassis plate having a central web which is affixed to the damping layer and mounting flanges facilitating the mounting of the disc drive. The damping layer and the central webs of the chassis plate and mounting plate form a laminate which provides constraint layer damping for the disc drive.

Abstract: An improved actuator assembly for a disc drive, the actuator assembly having an E-block which at a proximal end supports an array of read/write heads in reading and writing data relationship to a plurality of spinning data discs which create air currents that convectively cool the E-block, the E-block supporting at a distal end an electrical coil which interacts with a magnet assembly of the disc drive to selectively position the actuator assembly in response to control voltages introduced to the electrical coil. A portion of the control voltage is dissipated as heat energy by the electrical coil, and a heat transfer plate is provided to thermally connect the electrical coil and the E-block to provide conductive heat transfer of the heat energy to the E-block which acts as a heat sink for the electrical coil.

Abstract: The present invention includes a process and composition for treating skin disorders. The composition of the present invention comprises 94.0 to 99.2 percent by weight of cation-free water, 0.1 to 1.0 percent by weight of Calcium chloride, 0.0 to 2.0 percent by weight of linear long chain polyphosphate, 0.1 to 1.0 percent by weight of sodium bicarbonate and 0.5 to 3.0 percent by weight of cross-linked polyacrylamide polymer.

Abstract: An apparatus for improving the operational performance of a disc drive through the identification of vital product information associated with a head-disc assembly (HDA) of the disc drive. The disc drive comprises a printed wiring assembly (PWA) housing control circuitry for the disc drive. The HDA of the disc drive is operably coupled to the printed wiring assembly and includes a rotatable disc to which data are written by a controllably positionable head. A non-volatile memory device is mounted on the HDA and operably coupled to the PWA so that, when the disc drive is initialized, the PWA verifies the configuration of the HDA before proceeding with the initialization of the disc drive, thereby preventing errors and damage to the disc drive as a result of the installation of a new, replacement PWA in the disc drive, or the downloading of new, incorrect firmware to the PWA.

Abstract: An apparatus and associated method are disclosed for recovering user data from a data block in a disc drive in which user data are stored by way of a plurality of blocks on tracks of a disc, the blocks including data blocks in which the user data are stored in predefined increments. A head generates readback signals from the blocks and a read channel reconstructs the user data from the readback signals. An automatic gain control stage establishes a gain used to amplify the readback signal to a level suitable for use by the read channel. When an uncorrected read error is detected, the disc drive proceeds to read a previous block sequentially preceding the affected data block and sets the gain to a fixed value based upon the readback signals determined from the previous block. The fixed value of gain is then used to recover the user data from the affected data block.