Abstract: A C-shaped bobbin includes a bobbin base member adjacent and attached to a first lateral leg of an actuator coil. A bobbin recess, adjacent the bobbin base member, separates first and second bobbin wings. The first and second bobbin wings define first and second wing lengths measured parallel to first and second longitudinal legs of the coil, respectively, and also define first and second wing widths measured normal to the first and second longitudinal legs, respectively. The bobbin recess defines a recess depth measured normal to the first lateral leg, and defines a recess width measured parallel to the first lateral leg. Each of the first and second wing lengths is less than the length of the longitudinal legs. The recess depth is at least half a base member width. The recess width is at least twice the first wing width and/or the second wing width.

Abstract: A disk drive has an actuator coil that includes first and second lateral legs joined by first and second longitudinal legs to form a closed coil periphery. The first lateral leg is disposed closer to the actuator pivot bore than the second lateral leg. The first and second longitudinal legs join the second lateral leg at a first interior bend location and at a second interior bend location within the closed coil periphery, respectively. A bobbin is disposed within the closed coil periphery and contacts the conductive coil at two locations (e.g. the first interior bend location and the second interior bend location). Preferably, the bobbin defines a total bobbin length and an average bobbin width, and the total bobbin length is at least 3 times the average bobbin width.

Abstract: A voice coil includes a stack of a plurality of layers of aligned windings held between an outer holding portion and an inner holding portion of the carriage assembly. The carriage assembly is formed integrally with the voice coil through injection molding. An outermost peripheral layer is a conductive wire wound a number of turns that falls short of the number of turns required to constitute a complete layer. A step is thereby formed between the outermost peripheral layer and a layer adjacent thereto and inner therefrom. The outer holding portion includes a reinforcement portion formed thereon to cover part of a transverse end face of the voice coil. The outermost peripheral layer opposes a force acting on the outer holding portion from top downward and the reinforcement portion opposes a force acting on the outer holding portion from bottom upward.

Abstract: A balancer installed on an overmold of an head stack assembly to adjust balance of the head stack assembly is formed of stainless steel and demagnetized through a thermal treatment after the stainless steel is processed to have a balancer shape. The balancer has a recess formed at a side surface of the balancer to prevent separation of the balancer from the overmold. The stainless steel is austenite based stainless steel.

Abstract: A voice coil for a voice coil motor of a hard disk drive comprises an inner surface of the voice coil, which bounds a central space of the voice coil. A first outer surface of the voice coil is substantially parallel to a second outer surface of the voice coil. A constrained layer damper is attached to the inner surface of the voice coil by a coupler. The constrained layer damper comprises a first constraining layer coupled to a first surface of a viscoelastic damping layer. A second constraining layer is coupled to a second surface of the viscoelastic damping layer. The constrained layer damper is curved in a direction that is substantially perpendicular to the first outer surface of the voice coil and the second outer surface of the voice coil.

Abstract: The present invention is a system for stiffening a voice coil of a magnetic disk drive. One embodiment of the present invention are stressed skins that interconnect with an upper portion and a lower portion of the voice coil such that they are flush with the upper and lower surfaces of the voice coil. The stressed skins are adhered or otherwise interconnected to the voice coil thus allowing for bending, twisting, torsional, and various other loads that generate vibrations that affect the head of an actuator assembly to be dampened. One embodiment of the present invention includes two stressed skins interconnected to a voice coil constructed of carbon composite wherein the space therebetween is filled with a foam to provide additional stiffness and damping.

Abstract: An actuator/coil assembly (136) is disclosed where two different bonding operations are used. First, a bobbin (164) is overmolded to a coil (172), and a first overmolded part (176) is overmolded to both the coil (172) and a fan tail (152) of the actuator (140). The overmolding operation defines one or more adhesive receptacles (168) in the bobbin (164) on a perimeter that interfaces with the coil (172), and further defines one or more adhesive receptacles (180) in the first overmolded part (176) on a perimeter that interfaces with the coil (172) and that interfaces with the fan tail (152) of the actuator (140). Adhesive (184) is disposed within these receptacles (168, 180) to increase the stiffness of the actuator/coil assembly (136).

Abstract: Embodiments of the invention improve the impact-resisting performance of a disk drive. In a head actuator assembly according to an embodiment of the invention, the difference in resonance frequency between an arm bending mode and a coil bending mode is set at a predetermined value or less. Since there is a phase difference between these two modes, an oscillation gain in the arm bending mode can be greatly decreased by approximating the two resonance frequencies to each other. Consequently, it is possible to suppress collision of a head with a recording disk caused by an external shock and thereby improve the impact-resisting performance of a disk drive.

Abstract: An actuator for a disk drive. The actuator includes an actuator body The actuator body includes a main body section defining a horizontal plane orthogonal to an axis of rotation. The actuator body further includes an actuator arm extending from the main body section. The actuator body further includes two parallel support extensions extending from the main body section opposite the actuator arm. The support extensions cooperatively form a channel between the support extensions. The actuator body further includes a coil support tab disposed adjacent the support extensions and extending orthogonal to the horizontal plane. The actuator further includes a vertical coil defining a coil plane disposed orthogonal to the horizontal plane. The coil is disposed in mechanical communication with the support extensions and the coil support tab for supporting the coil within the channel.

Abstract: An actuator of a hard disk drive moving a magnetic head to a predetermined position on a disk to record and read out data on and from the disk, including a suspension supporting a slider on which the magnetic head is mounted, an actuator arm having a pivot hole formed in a middle portion of the actuator arm and installed on a base plate of the hard disk drive to be capable of pivoting, in which the suspension is installed at one end portion of the actuator arm, and a voice coil motor having a coil coupled to the other end portion of the actuator arm by interposing a molding portion therebetween and at least one magnet arranged to be separated a predetermined distance from the coil and to face at least one surface of an upper surface and a bottom surface of the coil.

Abstract: Positive retention features are provided on an actuator of a magnetic disk drive thereby increasing the structural rigidity of the actuator in attachment of a voice coil to the actuator. The positive retention features are defined by a plurality of protrusions having compound curved shapes including reverse or inward facing edges. The natural tendency of thermoplastic resin to shrink during cooling is used to an advantage in enhancing the rigidity of the connection between the voice coil and actuator body. The compound curved shapes of the positive retention features allows shrinkage of the thermoplastic resin in multiple directions around the features thereby maintaining desired actuator stiffness.

Abstract: An actuator arm assembly for a disk drive includes first and second stamped actuator arms including first and second arm portions, first and second body portions defining first and second body surfaces, and first and second coil-supporting arm portions defining first and second pairs of coil supporting arms for supporting a coil portion of a voice coil motor. When the first and second stamped actuator arms are attached to one another, the first pair of coil supporting arms faces and is in contact with the second pair of coil supporting arms to define first and second coil attachment surfaces, and the first body surface faces and is in contact with the second body surface to define a third coil attachment surface.

Abstract: A disk drive has an actuator supported for turning, and supporting magnetic heads for reading and writing data from and to a recording disk and a voice coil for driving the actuator. Plates are disposed near the voice coil so as to cover part of the voice coil. A hard disk drive capable of detachably combining with a PC card is formed by assembling separate component parts including a functional unit including a disk, a base plate holding the functional unit, a frame bumper disposed in a middle part of the assembly and serving as a shock-absorbing member, a card assembly provided with a connector to be connected to the slot of a PC card, and a top cover covering the functional unit held on the base plate. The frame bumper receives lateral shocks that act on the side surfaces of the hard disk drive.

Abstract: Positive retention features are provided on an actuator of a magnetic disk drive thereby increasing the structural rigidity of the actuator in attachment of a voice coil to the actuator. The positive retention features are defined by a plurality of protrusions having compound curved shapes including reverse or inward facing edges. The natural tendency of thermoplastic resin to shrink during cooling is used to an advantage in enhancing the rigidity of the connection between the voice coil and actuator body. The compound curved shapes of the positive retention features allows shrinkage of the thermoplastic resin in multiple directions around the features thereby maintaining desired actuator stiffness.

Abstract: A positioner (20) for a disk drive (10) that includes a magnet assembly (52), a conductor assembly (54), and a control system (22) is provided herein. The magnet assembly (52) includes a pair of magnet arrays (56A) (56B) and a pair of spaced apart flux return plates (75A) (75B). The conductor assembly (54) includes at least a first coil array (80) and a second coil array (82) that are substantially co-planar. The control system (22) directs current to electrically excite the coil arrays (80) (82) to maintain a data transducer (50) on a target track (32) of a storage disk (28).

Abstract: A technique of connection between VCM system wires and a FPC of a disk drive is improved in the following manner to enable miniaturization and thinning of the disk drive and reduction in cost. There is provided a disk drive comprising a disk-shaped medium for recording information, an actuator on which a head for recording/reproducing information is mounted, a VCM for driving the actuator, a coil holder supporting a coil of the VCM, a FPC for transmitting a signal, which is read by the head, and a signal to the VCM, a cut groove formed on a side of the coil holder, ends of coil lead wires and an end of a ground wire, which are arranged in the cut groove, and an end of the FPC inserted into the cut groove to thereby be connected to the ends of the coil lead wires and the end of ground wire.

Abstract: A disk drive includes a disk and a head stack assembly for reading and writing to the disk. The head stack assembly includes a body portion defining a through bore that defines a pivot axis; an actuator arm cantilevered from the body portion and a head gimbal assembly coupled to the actuator arm. A coil portion is cantilevered from the body portion in an opposite direction from the actuator arm. The coil portion defines first and second actuator fork members and includes a coil supported by the first and second actuator fork members. A bobbin is configured to stiffen the coil portion, and is attached to an inner periphery of the coil. The bobbin may define a first truss and a second truss that crosses the first truss. An adhesive is disposed between the bobbin and the wound coil.

Abstract: A damping assembly for the actuator of high performance disk drive assembly is formed from multiple materials. The damping assembly is added to the actuator to dampen vibration that occurs during operation of the drive. The damping assembly is connected to an exterior portion of a coil region of the actuator. The damping assembly helps dampen vibration modes for coil torsion and coil bending, thereby improving dynamics settling performance to improve overall file input/output throughput performance. This also allows for a higher voice coil motor torque constant by increasing the magnet radius, thereby also improving move time, which further improves file input/output throughput performance. The overall file performance is improved by reducing settling times associated with coil torsion and coil bending modes, and allowing a higher torque constant to also improve move time. Both of these effects contribute to improving file performance.

Abstract: A head stack assembly for a disk drive includes a rotary actuator assembly. The rotary actuator assembly includes an actuator body having a bore defining a pivot axis, an actuator arm cantilevered from the actuator body, and a coil portion cantilevered from the actuator body in a direction opposite from the actuator arm. The coil portion includes a coil support, a flat coil supported by the coil support, the flat coil including a coil surface generally perpendicular to the pivot axis, and a constrained layer damper attached to the coil surface. The constrained layer damper includes a stiffening layer having a coil-facing planar surface generally perpendicular to the pivot axis and an adhesive layer positioned between the coil-facing planar surface and the coil surface.

Abstract: A system and method for an improved magnetic head arm assembly (HAA) is disclosed. The HAA includes three principal components, a head gimbal assembly (HGA), a flexible printed circuit (FPC) assembly, and an actuator coil assembly. The design allows for HAA rigidity, yet each of the components is designable and manufacturable independent of one another, in addition to other advantages over current methods.

Abstract: An actuator for a disk drive. The actuator includes an actuator body defining an axis of rotation and including a body lateral surface disposed generally parallel to the axis of rotation. The actuator further includes an actuator arm extending from the actuator body. The actuator arm includes an arm base disposed adjacent the actuator body. The actuator further includes a coil support extending from the actuator body opposite the actuator arm. The coil support includes a coil support base disposed adjacent the actuator body. The actuator further includes a constrained layer damper disposed upon the body lateral surface extending from the arm base to the coil support base for mitigation of resonant vibration of the actuator arm and the coil support.

Abstract: A disk drive includes a disk, and a head stack assembly for reading and writing to the disk. The head stack assembly may include a body portion defining a through bore that defines a pivot axis; an actuator arm cantilevered from the body portion; a head gimbal assembly coupled to the actuator arm; a coil portion cantilevered from the body portion in an opposite direction from the actuator arm and a bobbin. The coil portion may define first and second actuator fork members and may include a wound coil supported by the first and second actuator fork members. The bobbin may be configured to stiffen the coil, and may include a first surface that faces the coil and that defines the thickness of the bobbin. The first surface defines one or more cleating features configured to increase the surface area of the first surface. The largest dimension of each of the cleating features in a direction that is parallel to the pivot axis may be selected to be less than the thickness of the bobbin.

Abstract: A head actuator mechanism and a method of manufacture for that mechanism are disclosed. The head actuator mechanism includes a head gimbal assembly coupled to the top support face of a bearing assembly and an actuator driving mechanism coupled to the opposite support face. The head gimbal assembly includes an actuator arm and a load beam, the actuator arm being mounted to the top support face. The actuator driving assembly includes a driving coil and a coil holder frame. The driving coil is positioned in a magnetic field created by a magnetic block and yoke.

Abstract: Disclosed is an actuator for use with a disk drive having a coil assembly designed to aid in heat convection from the coil of the coil assembly. The actuator includes a body portion for pivotally coupling to the disk drive and an actuator arm cantilevered from the body portion for supporting a head gimbal assembly (HGA). The actuator further includes a coil assembly having a coil and a fork. The fork is cantilevered from the body portion in an opposite direction from the actuator arm and includes a pair of opposed prongs to mount the coil. At least one of the prongs of the fork includes at least two opposed fins to aid in the convection of heat from the coil.

Abstract: A disk drive includes a disk drive base and a rotary actuator coupled to the disk drive base. The rotary actuator includes an actuator body including a bore defining a longitudinal axis. The rotary actuator further includes a coil portion including a coil and a support element for supporting the coil. The coil support element is integrally formed with the actuator body and radially extends from the actuator body. The coil support element has a coil supporting surface generally perpendicular to the longitudinal axis. The coil is attached to the coil supporting surface. The coil support element is sized and configured to support the coil and formed of a thermo-conductive material for dissipating heat from the coil.

Abstract: In an actuator having a coil disposed between yokes opposing to each other via a specified space, stepped portions are formed at the inner sides of two arms which support the coil, and at the stepped portion are formed through-holes whose diameter is gradually reduced from the bottom to top of the stepped portion. The coil and the arms are joined together by filling the stepped portions and through-holes with a holding member made up of resin. By this configuration, in an actuator used for a disk unit or the like, it is possible to completely secure a coil on a carriage while reducing the unit in thickness.

Abstract: A positioner (20) for a disk drive (10) that includes a magnet assembly (52), a conductor assembly (54), and a control system (22) is provided herein. The magnet assembly (52) includes a pair of magnet arrays (56A) (56B) and a pair of spaced apart flux return plates (75A) (75B). The conductor assembly (54) includes at least a first coil array (80) and a second coil array (82) that are substantially co-planar. The control system (22) directs current to electrically excite the coil arrays (80) (82) to maintain a data transducer (50) on a target track (32) of a storage disk (28).

Abstract: An E-block of an actuator for use in a data handling system to support a read/write head adjacent a recording surface. The E-block is formed by providing feed stock along a planar orientation, drawing a portion of the feed stock out of plane to form an extension portion, and stamping the feed stock to separate an actuator arm member having a substantially planar actuator arm from which the extension portion extends, the actuator arm configured to support the read/write head. A planar motor support member configured to support a coil of an actuator motor is also stamped from the feed stock. The actuator arm member and the motor support member are stacked and attached using a suitable process such as swaging or welding. The extension portion of the actuator arm member establishes a desired axial separation distance between the motor support member and the actuator arm.

Abstract: An actuator assembly is provided for a computer disc drive. The actuator assembly includes an actuator body that supports a shell head support arm and/or a shell coil yoke. The coil yoke supports the coil of the VCM. The actuator body pivots about a pivot axis and is attached to the cartridge bearing assembly disposed within an inner hollow of the actuator body. The head support arm is a shell having a core, a first surface and a second surface. The first surface of the head support arm is concave and the second surface of the head support arm is convex. The head support arm is connected to the actuator body at a proximal end. At a distal end of the head support arm, there is a flat portion with a swage hole for connection of the flexure assembly.

Abstract: An actuator assembly for use in a data storage device is described that has features that reduce off-track writes due to coil popping. The fantail portion of the actuator includes thermal restraint features that engage with the over-mold, and the thermal restraint feature are positioned prevent the over-mold from separating from the actuator as a result of the over-mold and the actuator having different coefficients of thermal expansion. The thermal restraint features reduce the length of effective interface between the actuator and the over-mold acted upon by shear forces due to coefficient of thermal expansion mismatch. In one example, the thermal restraint features are holes that extend through the actuator, to allow the over-mold to flow through the holes and connect on both sides of the fantail during molding, effectively interlocking the fantail portion to the over-mold.

Abstract: An actuator arm for a rotary actuator assembly of a disc drive comprises a substantially planar sheet of pliable material defining a longitudinal actuator arm having longitudinal edges, a distal end supporting the transducer, a proximal end supporting an actuator coil. Strut means integral with the sheet extends substantially normal to the plane of the sheet along at least a portion of at least one longitudinal edge and the proximal end of the arm to provide rigidity to at least a portion of the arm. In one embodiment, an integral strut portion defines a support for the actuator coil. In another embodiment, integral strut portions extend along opposite longitudinal edges to a location proximal the distal end to define a rigid portion between the strut portions and a flexible suspension region distal to the rigid portion.

Abstract: An information handling system including a base, a disc rotatably attached to the base; and an actuator assembly movably attached to the base. The actuator assembly also has a main body which includes a pivoting portion, an actuator arm attached to the main body, and a yoke attached to the main body. The yoke has a roughened bonding surface. A voice coil bonded to the yoke. The bonding surface has a plurality of grooves therein. The grooves or any roughening results in a plurality of features on the bonding surface of the yoke which increases the area of the bonding surface for bonding the voice coil to the yoke of the actuator assembly. The plurality of features in the bonding surface are designed to minimize cracks or potential cracking in the yoke of the actuator assembly.

Abstract: An actuator of a hard disk drive moves a magnetic head to record and reproduce data with respect to a disk to a predetermined position on the disk. The actuator includes a suspension supporting a slider where the magnetic head is mounted, and an arm included on a base plate of the hard disk drive to be capable of pivoting and having the suspension included at a leading end portion of the arm and a coil of a voice coil motor coupled to a rear end portion of the arm. The coil is coupled to the rear end portion of the arm by an outer mold formed to encompass an outer circumference of the coil, an inner mold formed inside the coil, and a connection mold connecting the outer mold and the inner mold is formed at least part of a surface of a non-effective portion of the coil except for an effective portion arranged to be perpendicular to a direction in which the arm pivots.

Abstract: An actuator arm for a disc drive data storage device has an upper outer surface in a first plane, a lower outer surface in a second plane substantially parallel to the first plane, a peripheral outer surface substantially perpendicular to the first and second planes, and a voice coil embedded within the outer surfaces of the actuator arm. The actuator arm is used in a disc drive containing one or more data storage discs and preferably has a pre-amplifier embedded within the outer surfaces of the actuator arm as well as conductors preferably between the read/write head and the pre-amplifier within the outer surfaces of the actuator arm.

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: A hard disk drive apparatus is capable of reducing a noise effectively during operation and capable of enhancing the reliability of the drive. The hard disk drive has first and second ribs that are formed near a pivot for an actuator so that a tilt of the pivot is prevented when the actuator is operated. Also, vibration absorbing members are interposed between the first and second ribs on the side of a base and a cover so that the vibration absorbing members are brought into contact with the cover. These vibration absorbing members are located in an intermediate portion between fixing places for fixing the cover to the base and a fixing place for fixing the cover to the pivot.

Abstract: A thermally conducting and electrically insulating overmold encapsulates and supports an actuator coil in a disc drive assembly. The overmold is made from a base resin mixed with a ceramic filler compound such as boron nitride, alumina, aluminum nitride, magnesium oxide, zinc oxide, silicon carbide, beryllium oxide, chromium oxide or some combination thereof. The base resin is preferably polypheneline sulfide. Glass filler and/or a coupling agent are also preferably added. The overmold reduces off track read/write head position errors due to popping caused by thermal expansion and contraction of the actuator coil.

Abstract: A voice coil for a head positional assembly of a disc drive. The voice coil including a dampener which dampens vibrations occurring in the voice coil. The dampener includes a constraint material and a viscoelastic material.

Abstract: A thermally conducting and electrically insulating overmold encapsulates and supports an actuator coil in a disc drive assembly. The overmold is made from a base resin mixed with a ceramic filler compound such as boron nitride, alumina, aluminum nitride, magnesium oxide, zinc oxide, silicon carbide, beryllium oxide, chromium oxide or some combination thereof. The base resin is preferably polypheneline sulfide. Glass filler and/or a coupling agent are also preferably added. The overmold reduces off track read/write head position errors due to popping caused by thermal expansion and contraction of the actuator coil.

Abstract: Apparatus and method for cooling the actuator coil with a suitable heat sink structure. The heat sink thermally couples the coil to one or more of the head-carrying arms, which are positioned close enough to the disc stack that rotation of the stack cools them. In one embodiment, a gap is formed between the coil and a thermal conduit, and the gap is made wide enough to allow a majority of the gap to be filed with a solid dielectric. Another embodiment is a method for controlling the minimum gap thickness. In yet another embodiment, a rotary actuator includes a heat conduit with a concave surface for bonding to the coil, increasing rigidity and thermal conduction.

Abstract: The present invention is an apparatus and method for an improved actuator arm assembly in a disc drive. This invention results from the realization that structurally inferior actuator assemblies create low frequency, high amplitude resonances. This invention reduces resonances through the utilization of a voice coil motor overmolding technique that additionally incorporates a stiffening member to increase the rigidity of the actuator assembly.

Abstract: A disk drive having a novel actuator assembly. The actuator assembly comprises a voice coil motor assembly, a pivotable actuator arm, and a head gimbal assembly including a read/write head. The voice coil motor assembly is attached at a back end of the actuator arm, and the head gimbal assembly is mounted on the actuator arm on a front end opposite of the back end. The voice coil motor assembly includes a voice coil interposed between two magnets and a top plate and a bottom plate. The voice coil motor assembly is secured to the base of the disk drive by posts. The actuator arm includes the back end, a pivot point and impeding apertures. The impeding apertures include two holes located near the back end of the actuator arm between the pivot point and the voice coil motor assembly and extend entirely through the actuator arm. The actuator arm may also include plugging members. The plugging members are inserted into the impeding apertures and extend entirely through the impeding apertures.

Abstract: An actuator assembly in a disk drive includes an actuator arm having a first distal end supporting a transducer head and a second distal end opposite to said first distal end supporting a movable voice coil section of a voice coil motor. The voice coil section comprises a coil, inner and outer bobbins positioned respectively at inner and outer sides of the coil, and a plurality of coil guides installed at respective corners of the inner bobbin for fixedly guiding the coil so as to prevent distortion due to difference in thermal expansion coefficients between the plastic bobbins and the coil during insertion molding in order to enhance a combining force between the coil and the bobbins. A gap of at least 0.5 mm is formed between the coil guides and the coil for separating the coil from the coil guides to prevent damages due to friction therefrom. The inner bobbin further comprises a plurality of guide holes perforated at corners for mounting the coil guides.

Abstract: Disclosed is an actuator of a hard disk drive. The actuator comprises a bobbin having an outside bobbin part made of plastic, an inside bobbin part of a lower height than the outside bobbin part, and a coil intervened between the outside bobbin part and the inside bobbin part by insert molding; a rib portion having a predetermined width and formed along a boundary region between the inside bobbin part and the coil such that it has the same height as the outside bobbin part; and a plurality of connecting portions having a selected width and each being branched from a center portion of the inside bobbin part and linked to a desired position on the rib portion such that it has the same height as the rib portion.

Abstract: A bobbin for providing a heat sink for an actuator coil of a voice coil motor, the actuator coil having a plurality of windings arranged about a central aperture, the bobbin having a body member supported within the central aperture of the actuator coil. The body member has a plurality of fins which increase the surface area within the actuator coil to provide enhanced heat dissipation. The bobbin is formed from a thermally conductive, dielectric material to facilitate the dissipation of heat generated in response to the application of current to the actuator coil to reduce the operational temperature thereof while preventing detrimental eddy currents, thereby allowing an increased current flow to effectuate a decrease in seek time.