Abstract: An aspect of the invention can be regarded as a disk drive that includes a disk drive base and a spindle motor hub rotatably coupled to the disk drive base. The disk drive further includes a first disk disposed about the spindle motor hub. The disk drive further includes a second disk disposed about the spindle motor hub. The disk drive further includes a first disk spacer disposed between and in mechanical communication with the first and second disks. The first disk spacer has a first disk spacer first side disposed adjacent the first disk and an opposing first disk spacer second side disposed adjacent the second disk. The first disk spacer first side is defined by a first disk spacer first surface pattern. The first disk spacer second side is defined by a first disk spacer second surface pattern different than the first disk spacer first surface pattern.

Abstract: Faulty engagement due to low surface precision of the engaging surfaces of a center core of a disk cartridge and a drive spindle is resolved. The center core 10 is positioned on the drive spindle 20 in a state where the center core 10 is in point contact with the drive spindle 20 at a minimum of three spots upon chucking. A minimum of three protrusions 10d are provided on the bottom surface of the center core 10, and lower ends P of the protrusions 10d are in point contact with the upper surface 21a of the drive spindle 20.

Abstract: A disc clamp assembly for securing a data storage disc to a drive motor in a disc drive includes a disc clamp having a central portion that can be secured to a drive motor, a raised portion extending around the central portion, and a contact portion extending around the raised portion for pressing down on the disc to secure the disc to the drive motor. The contact portion has an upwardly extending rim, and the rim has at least fifteen spaced apart upwardly extending projections positioned around the rim. A balance ring is seated in the contact portion.

Abstract: An apparatus and method for securing an information storage disc within a disc drive incorporates a rotatable spindle hub and a clamping ring. The clamping ring is positioned between an inner edge of the information storage disc and the rotatable spindle hub. The clamping ring is a strip of resilient sheet material and defines a series of serpentine shaped curves that alternatively contact the inner edge of the information storage disc and a sidewall of the rotatable spindle hub. The clamping ring applies a radial force to the information storage disc. In some cases the clamping ring may define a series of equally spaced apart, radially extending, tabs from the top and bottom edges of the clamping ring. The tabs from the top edge contact the top surface of the information storage disc at an inner diameter of the information storage disc. The tabs from the bottom edge contact the bottom surface of the information storage disc at an inner diameter of the information storage disc.

Abstract: A disk clamp of a hard disk drive to affix a magnetic disk that stores data to a spindle motor of the hard disk drive includes a pressing portion formed along an outer circumference of the disk clamp at an edge portion, to press an upper surface of the disk in a vertical direction, a stress distribution portion formed inside the pressing portion and having a profile with a curved shape bulged upward to distribute stress applied to the disk, and a plurality of screw coupling holes into which screws are inserted to be coupled to an upper end portion of the spindle motor and provided at a predetermined distance in a circumferential direction inside the stress distribution portion. Thus, since the stress applied to the disk is uniformly distributed in the circumferential direction of the disk by the stress distribution portion, flatness of the disk is improved.

Abstract: A method for minimizing unbalance in the disc pack of a disc drive where the unbalance of the spindle motor is quantified and incorporated into the biasing assembly of the disc pack. In the assembly process, the discs are biased in a manner such that the unbalance of the spindle motor is considered.

Abstract: An apparatus for securing the internal rotational components of a disk drive utilizes an annular clamp retention device. The clamp retention device has a rigid, metallic, main ring body from which protrudes a plurality of compliant tabs having a generally L-shaped cross-section. The compliant tabs extend radially inward from the body to form an inner circular array of the tabs. In addition, a plurality of rigid planar flanges, which are larger than the compliant tabs, extend radially outward from the body. The compliant tabs are designed to engage the hub and cartridge of the disk drive rotational components at the upper end of the disk stack.

Abstract: A disk drive device includes a recording medium, a head slider having a head element for recording data on the recording medium and for reading data recorded on the recording medium, a spindle motor for rotating the recording medium, and a clamp for applying a pressing force to the recording medium to fasten the recording medium to the spindle motor. The disk drive device has a feature in which a film body formed from a material which is more pliable than a material forming the clamp is interposed between the clamp and the recording medium. Even if the clamp does not have a high flatness, the film body absorbs irregularities of the clamp. Thus, it is possible to fasten the recording medium with the clamp while apparently keeping flatness.

Abstract: To alleviate excessive non-repeatable runout (NRRO) on heads between discs, an original multi-disc design is adapted by (a) reducing the number of discs in the stack and (b) configuring the disc drive of the adapted design with a larger nominal inter-disc separation than that of the original design. In one embodiment, the larger separation is maintained by an increased number of disc spacers between each consecutive pair of the discs in the disc stack of the modified design. The result of such a design adaptation is a disc drive with better performance characteristics than would exist by the original design.

Abstract: A spindle motor including a rotatable hub is provided on a case, and a disk is fitted on an outer periphery of the hub. A disk damper is fixed to an end portion of the hub to hold the disk on the hub. The disk damper integrally includes a clamp portion fixed to the end portion of the hub to hold a centre portion of the disk, and a substantially annular straightening portion extending outwards from the clamp portion in a radial direction and facing to a surface of the disk with a predetermined gap.

Abstract: A spring disk clamp is provided for securing one or more data storage disks to a disk drive without the need for screws. The disk clamp incorporates an angled surface defining the central opening of the clamp which is positioned adjacent a sloping surface of the hub. An external axial load applied to the clamp deflects the clamp, and allows a retaining member to be wedged between the clamp and the hub. Stabilizing features such as O-rings and the like are also eliminated as the clamp of the invention provides both radial and axial stabilization to the disk pack in its mounting to the hub.

Abstract: A disc media retainer used to secure one or more discs to a hub member without applying forces to the discs that could cause them to become warped. The disc media retainer generally includes a disc hub member having an annular flange, a disc supported on the annular flange, and a retaining ring adapted to secure the disc to the hub member. In accordance with one embodiment, the retaining ring is swaged within an annular groove of the disc hub member and a radial gap between the disc hub member and an interior edge of the disc, and over a top surface of the disc adjacent the interior edge of the disc. In accordance with another embodiment, the retaining ring is wedged within the radial gap, welded to the disc hub member, and swaged over a top surface of the disc adjacent the interior edge.

Abstract: A disk clamp of a hard disk drive installs a disk firmly for storing data using a spindle motor of the hard disk drive. The disk includes a vertical pressing portion, formed along an edge portion of the disk, for pressing an upper surface of the disk in a vertical direction, a plurality of horizontal pressing portions, formed inside the vertical pressing portion to protrude downward and be inserted between an outer circumference of the spindle motor and an inner circumference of the disk, to press an inner circumferential surface of the disk outwardly, and a plurality of screw coupling holes formed inside the horizontal pressing portion, through which screws are inserted to be coupled to an upper end portion of the spindle motor. The horizontal pressing portions are formed in at least three positions in a circumferential direction at regular intervals or at four positions at an interval of approximately 90° in the circumferential direction.

Abstract: Herein is disclosed a method and apparatus for coupling a disc to a hub, so as to dampen radial vibrations of the disc. A hub rotates and is coupled to a magnetically encodable disc via a flexible joint. The flexible joint may be made out of a viscoelatic adhesive. There exists no rigid coupling between the disc and the hub, meaning that radial vibrations of the hub result in compression or decompression of the flexible joint, rather than in translation of the disc. The disc may be coupled to the hub by applying a viscoelastic adhesive to a hub, and applying a disc to the viscoelastic adhesive without otherwise rigidly coupling the disc to the hub.

Abstract: A disc tolerance ring for centering a disc clamp on a spindle hub. The disc tolerance ring has a first surface and a second surface. The first surface is located between an inner edge of the disc clamp and an outer surface of the spindle hub. In specific embodiments, the disc tolerance ring has a first circumferential section and a second circumferential section and the first circumferential section is a continuous band and the second circumferential section includes alternating notches and members depending from the first circumferential section.

Abstract: A chuck that can center a disk. The chuck may be part of a spindle motor that is integrated into a servo writer. The chuck includes a plurality of cartridges that are attached to a post. The cartridges are coupled to a source of air. Each cartridge may include a biasing element that can move within a variable orifice and engage an inner edge of the disk. The biasing elements move until each cartridge exerts an equal force onto the disk. The equal forces will center the disk onto the spindle motor.

Abstract: A system for exchanging digital data among a plurality of hand-held computer devices. Digital signals are written by a first hand-held device to a mini-cartridge that mini-cartridge is inter-operable among a class of hand-held device, each of which is equipped with a mini disk drive. A common digital data format is employed to further facilitate exchange of data between devices.

Abstract: A disc fixing apparatus and associated methodology for fixing a data storage disc in rotation with the hub of a motor that is rotatable around a motor axis of rotation. The disc fixing apparatus comprises a clamp engaging the hub and comprising a reference surface associated with the clamp axis of rotation. A fastener comprising a registration feature cooperates with the reference surface, registering the clamp with the fastener. The fastener is attached to the motor hub fixing the disc and hub in rotation and registering the clamp to the motor axis of rotation. An associated method is provided for fixing a disc in balanced rotation with a rotatable hub of a motor around a motor axis of rotation.

Abstract: An apparatus and method for balancing a disc stack assembly of a disc drive where a clamp is used as a counter-balance as well as for securing a disc to the disc stack assembly. The clamp and spindle motor are configured for positive engagement and alignment with the use of a minimal number of parts. The clamp includes a cavity through which a protrusion or a shaft of the spindle motor hub may extend. The clamp may be further secured in a desired orientation by the use of a single fastener.

Abstract: A media rework tool for discs and/or a spindle motor carrying a disc pack is disclosed that has a slider plate mounted on a base for lateral movement between a retracted position and an extended position. The slider plate holds a spindle motor with a disc pack mounted on it, and moves between the two positions. The tool includes a gripper assembly having a plurality of opposing arms for grasping predetermined discs within a disc pack on the spindle motor when the slider plate is in the retracted position. The gripper assembly raises the predetermined discs and any intermediate spacer rings upward for temporary storage on a media guide to allow the remainder of the disc pack to be reworked, such as for replacement of a defective disc or spindle motor when the slider plate is laterally moved to the extended position. Following reworking of the remainder of the disc pack, the spindle motor is returned to its centered position relative to the media guide and the gripper assembly.

Abstract: A disk chuck which centers and clamps data storage disks during a disk formatting process. The disk chuck is designed to clamp or unclamp the disks at the same time. The disk chuck includes a hollow main shaft which orderly fits and seats the disks thereon and a piston which is situated in the hollow main shaft so as to axially move in the hollow main shaft in opposite directions. A clamping shaft is axially received in the hollow main shaft and coupled to the piston so as to move along with the piston in the same direction to clamp or unclamp the disks seated on the hollow main shaft. An upper end of the clamping shaft having a disk clamping part extends to project beyond an upper end of the hollow main shaft.

Abstract: An information storage disk holding member for holding an information storage disk in position in an information storage disk drive device, the holding member being made of glass-ceramics in which a crystal phase is dispersed in a glass matrix. The holding member has specific rigidity (Young's modulus/specific gravity) of not greater than 37 GPa, specific gravity of not greater than 3.0, coefficient of thermal expansion within a range from −50° C. to +70° C. which is within a range from +35×10−7/° C. to +130×10−7/° C., Young's modulus within a range from 95 GPa to 130 GPa, specific gravity within a range from 2.40 to 2.60 and bending strength within a range from 400 MPa to 800 MPa.

Abstract: A disc stabilizer for use in a spin-stand tester having a spindle motor for rotating a disc is provided. The spin-stand tester is capable of positioning a transducing head adjacent a first surface of the disc. The disc stabilizer includes a vacuum plate coupled to a spindle of the spindle motor. The vacuum plate has a top surface and a bottom surface opposite the top surface. At least one of the top and the bottom surfaces is a grooved surface including multiple vacuum channels. The grooved surface is substantially in contact with a second surface of the disc. Vacuum distributed through the multiple vacuum channels of the grooved surface is applied directly to the second surface of the disc, thereby holding the disc in place.

Abstract: An apparatus and method for uniformly centering and retaining an information storage disc on a spindle motor. A disc drive spindle motor assembly including a rotatable motor spindle having a top portion and a hub portion, and an annular disc mounted over the top portion and supported on the hub portion. The assembly further includes an annular disc clamp mounted over the top portion of the spindle, and having a centering portion and a peripheral clamping portion. A disc clamp retainer is fastened to the spindle applying a compressive force to the disc clamp to secure the disc against the hub portion. The centering portion of the disc clamp has a series of spaced centering tabs adapted to abut the spindle and symmetrically push against the annular disc when the compressive force is applied to the disc clamp.

Abstract: The object of the present invention is to provide a hard disk drive device having a bearing device of larger size and sufficient strength, improved impact resistance, high accuracy of rotation, and high reliability.

Abstract: A disk drive contains an integrally-formed one-piece hub, clamp and rotor housing, which is preferably injection-molded plastic. In the preferred embodiment, the hub includes a hollow cylindrical portion for surrounding a set of bearings mounted on a central shaft, and a flange portion extending from the middle of the cylinder and supporting a single disk. Compliant clamping fingers on the upper surface of the flange engage the disk through its central hole. The fingers are inclined slightly outward, and include a pawl at the end of each finger. During assembly, the disk is forced over the pawls of the fingers until they engage the disk. The fingers, being slightly elastic, will deform to permit the disk to slide over the pawls, and then return to lock the disk in place. The fingers automatically center the disk about the hub axis, without the need for centering tools. The hub also serves as a housing for the rotor of a spindle motor which rotates the disk.

Abstract: Method for balancing a rotary object, such as a disc drive disc pack. A balance correction member is provided as a C-shaped ring formed from a length of wire of nominally uniform cross-sectional area. The member has a substantially elliptical shape in an uncompressed state. During installation, the amount of imbalance in the disc pack is measured and a member with an appropriate length is selected and compressed to a substantially circular shape. The compressed member is then placed adjacent the disc pack so that the member expands to compressingly engage an annular recess in the disc pack. The member is preferably installed using an automated dynamic balance correction station as part of a high volume disc drive manufacturing environment.

Abstract: The performance of a leaf spring disc clamp can be enhanced by utilizing a roughly triangular shape for the center aperture. Such a disc clamp exhibits a substantially more uniform distribution of clamping force on the data disc and thereby reduces the deformation of the disc. It has further been determined that a stiffening rib located adjacent to the rim portion which contacts the data disc also leads to more uniform distribution of clamping force. Lastly, vibrations in a leaf spring disc clamp from external shocks or drive operation can be reduced utilizing a dampening ring of visco-elastic material. The dampening ring can be fastened to the surface of the disc clamp or placed within a rib on the disc clamp.

Abstract: A disc clamp for a disc drive used to secure a disc stack in position when the disc is mounted to a hub. The disc clamp is annular with a central opening and has three tabs. The three equidistantly spaced tabs extend radially inward from the circumferential edge of the central opening. The disc clamp is resiliently flexible and has a continuous annular disc contact region adjacent to an outer circumferential edge. The disc clamp also has at least three screw openings each for receiving a screw fastener to fasten the disc clamp to the hub in the clamping position. The disc clamp resiliently flexes in the clamping position to cause the annular disc contact region to bear against the surface of the outermost stacked disc to clamp the disc stack against radial and axial movement.

Abstract: An inventive method of manufacturing precisely-compressed multi-layer stacks is presented. Two stacks are assembled. One stack, having a compression sensor between two layers, is then compressed with an initial compression force, and the signal from the sensor is measured. The other stack is then compressed with a force derived from the measurement.

Abstract: A spindle motor includes a rotor case in which a shaft support is located at the center of the rotor and disc mounting guides are located around the shaft support at a predetermined interval, a shaft installed at the shaft support, a disc chuck spring having at least one disc inner hole chucking portion and arranged at the rotor case such that at least one disc inner hole chucking portion slightly protrudes between the disc mounting guides, a magnet inside the rotor case, an armature stator facing the magnet via a gap, and a stator base where the armature stator is located, the stator base supporting the shaft inside the armature stator.

Abstract: A brushless motor having a turntable including a rotor in which a turntable is integrally formed on the outer side of a rotor case and a magnet is arranged on the inner side thereof, a shaft for supporting the rotor, a stator base for supporting the shaft, and a stator formed on a portion of the stator base for driving the rotor, in which the turntable which has a media mounting portion at least partly formed of resin, includes a media installation guide formed of the same resin to support a medium, and at least one media inner diameter chucking spring member integrally formed of resin to have a diameter slightly greater than the media installation guide and the inner diameter of the media.

Abstract: A recording disk apparatus includes a recording disk supported by a rotation axis. A clamp is fixed at the tip end of the rotation axis by screws so as to urge the recording disk against a flange at the base end of the rotation axis. The screws are disposed along an imaginary circle concentric to the rotation axis so as to fix a plane body of the clamp at the tip end of the rotation axis. A rigidity reduction mechanism reduces rigidity of the plane body at an intermediate area relative to the screw bore areas, which intermediate area is defined between the screw bore areas along the imaginary circle. The rigidity reduction mechanism serves to suppress the undulation of the magnetic disk.

Abstract: The present invention provides a disc clamp for use with a disc stack assembly where the disc stack assembly is designed for rotation about an axis. The disc clamp includes a set of openings defined by a body, such that each opening has line symmetry about a line of reflection that intersects the axis. The disc clamp also includes a set of flanges, each which extends from the body into one of the openings. The disc clamp is made such that the set of openings has rotational symmetry about the axis and the set of flanges is rotationally asymmetrical about the axis.

Abstract: A outer circumferential part of a body to be coupled having an annular groove formed 31 in the outer periphery of a shaft 1 is press-fitted into the inner circumferential part of a coupling hole in the central portion of a hub 2, the vicinity of the hole in the end of the hub is plastic-deformed over the whole periphery, and material for the hub is caused to plastic-flow so as to bury a recess of the shaft, and to apply compression stress to the shaft, whereby a coupling force between a thin hub and a small diameter shaft is obtained by shearing force and compressing force of the material for the hub.

Abstract: In a disk drive of the type in which a removable cartridge has a storage disk inserted therein, a spindle motor includes a spindle having a hub and a rotor cup. Only the spindle and the rotor cup are translated in the Z-axis into engagement of the hub with the disk as the cartridge is inserted into the drive. A cam and a lever which is rotated as the cartridge is inserted into the drive translate the spindle and the rotor cup in the Z-axis.

Abstract: The performance of a leaf spring disc clamp can be enhanced by increasing the flatness of an annular contact surface while the clamp is in its fully deflected, installed position. Such a disc clamp exhibits substantially improved flatness at a minor expense in applied axial force. It has been determined that a lapping process can be used to achieve a desired level of performance without fully deflecting the clamp prior to installation in a disc pack. The performance of the disc clamp may be further enhanced by providing one or more slots within a central portion of the disc clamp and joining the slots with a central aperture in the central portion in order to more uniformly distribute the clamping force around a peripheral portion of the disc clamp and thereby improve disc flatness during disc drive operation.

Abstract: An automatic balancing apparatus which includes a support shaft which is rotated by a drive; a case body which is fixed to the support shaft and which rotates together with the support shaft; a ring magnet which is placed at the inside corner, in the radial direction, of an inner space of the case body; and a balancing member. The balancing member further includes a plurality of magnetic bodies which are movable in the inner space of the case body and which can be drawn up by the magnetic field of the ring magnet. When the rotational frequency of a rotor, which rotates together with the case body, exceeds the resonant frequency, the automatic balancing apparatus reduces vibrations of the rotor; and the outer circumference of the ring magnet has a flat portion.

Abstract: An electronic apparatus, such as an on-vehicle navigation system, is provided. The apparatus comprises a hard disc container (2) and a contacting piece (31) for grounding. The hard disc container contains a hard disc unit (7) detachably loaded thereinto. A loading/unloading passage (21) through which the hard disc unit is loaded and unloaded is formed in the container. The contacting piece is disposed in the loading/unloading passage. When the hard disc unit is loaded into the container, the hard disc unit is made to come into contact to the contacting piece before an electrical connection between the hard disc and the hard disc container is realized. Thus, even if static electricity is charged on the hard disc unit, the static electricity is grounded steadily prior to the electrical connection, thereby no harm being given to data stored by a hard disc incorporated in the hard disc unit.

Abstract: A spindle motor assembly that includes an elastomer which couples a disk to a motor hub. The elastomer centers the disk with the motor hub. Centering the disk improves the overall balance of the spindle motor assembly.

Abstract: A chuck that can center a disk. The chuck may be part of a spindle motor that is integrated into a servo writer. The chuck includes a plurality of cartridges that are attached to a post. The cartridges are coupled to a source of air. Each cartridge may include a biasing element that can move within a variable orifice and engage an inner edge of the disk. The biasing elements move until each cartridge exerts an equal force onto the disk. The equal forces will center the disk onto the spindle motor.

Abstract: A disc-shaped recording medium for which information signals are recorded and/or reproduced in a state in which a rotating recording and/or reproducing head is floated a pre-set distance from a signal recording region carrying surface of the disc-shaped recording medium. The disc-shaped recording medium has an area radially outside of the outer perimeter of center opening by at least 0.1 mm clamped by a clamp mechanism. This area is coplanar as each surface of the disc-shaped recording medium carrying the signal recording region. It is possible in this manner to prevent eccentricity of the rotating disc-shaped recording medium and consequent collision of the recording and/or reproducing head against the disc-shaped recording medium.

Abstract: Apparatus and method for individually clamping discs in a disc stack assembly to improve mechanical shock resistance of a disc drive. A clamping spacer includes a circumferentially extending body portion having a hub contact surface rigidly affixable to a hub of a spindle motor used to rotate first and second discs. The clamping spacer further includes top and bottom spring flanges which extend radially from the body portion away from the spindle motor hub so that the body portion and the spring flanges form a generally c-shaped cross-section. When the body portion is affixed to the spindle motor hub above the first disc and below the second disc, the bottom spring flange exerts a first axially directed clamping force upon the first disc and the top spring flange independently exerts a second axially directed clamping force upon the second disc.

Abstract: The method comprises the steps of: forming an integrated device including a microactuator in a semiconductor material wafer; forming an immobilization structure of organic material on the wafer; simultaneously forming a securing flange integral with the microactuator and electrical connections for connecting the integrated device to a read/write head; bonding a transducer supporting the read/write head to the securing flange; connecting the electrical connections to the read/write head; cutting the wafer into dices; bonding the microactuator to a suspension; and removing the immobilization structure.

Abstract: A disc tolerance ring for centering a disc clamp on a spindle hub. The disc tolerance ring has a first surface and a second surface. The first surface is located between an inner edge of the disc clamp and an outer surface of the spindle hub. In specific embodiments, the disc tolerance ring has a first circumferential section and a second circumferential section and the first circumferential section is a continuous band and the second circumferential section includes alternating notches and members depending from the first circumferential section.

Abstract: A disk drive apparatus is which includes an improved disk clamp/drive spindle interface. Axial positioning of the disk clamp on the drive spindle is restrainably maintained so that an outer peripheral surface of the disk clamp applies a clamping force to one or more storage disks. In one embodiment, the top end of a drive spindle is provided with a plurality of outwardly extending tabs. Correspondingly, a disk clamp is provided with a plurality of tabs which extend inwardly at a central aperture. The disk clamp tabs and drive spindle tabs are provided so that the disk clamp may be axially advanced about the drive spindle during assembly with the disk clamp tabs passing between drive spindle tabs. In conjunction with such assembly, the disk clamp may be deflected or bowed, toward the spindle center axis via the application of a loading force (e.g. by employing an assembly tool that deflects and maintains deflection of the disk clamp during assembly).

Abstract: An apparatus and method for securing an information storage disc within a disc drive. A disc drive spindle motor assembly including a spindle and a hub portion extending radially outward from the spindle, the hub portion defining a top surface. An information storage disc is mounted on the hub portion, the information storage disc having a top surface. The assembly further includes an annular disc clamp forming a central aperture having a middle annular raised portion, an outer annular periphery portion, and at least one inner centering portion including an inner vertical peripheral surface. The central aperture of the disc clamp is sized to receive the spindle to allow the inner centering portion to center the disc clamp about the spindle, while the outer periphery engages the top surface of the information storage disc, and the middle annular raised portion extends above the top surface of the hub portion and is adapted to receive a downwardly directed force.

Abstract: A disc stack assembly for use in a disc drive. A spindle motor hub includes an annular ring recess. A disc is clamped to the spindle motor hub by a disc clamp assembly comprising a clamp plate and a retaining ring. The clamp plate includes an inner ring engagement portion, an outer disc engagement portion, and an initial, substantially planar shape in an undeformed state. The retaining ring is secured within the annular ring recess and maintains the clamp plate in a conically deformed state so that the inner ring engagement portion of the clamp plate applies a first moment force against the retaining ring while the outer disc engagement portion of the clamp plate applies a second moment force as an axially directed clamping force upon the disc.

Abstract: The object is to improve the productivity and serviceability in the assembling work by exalting the assembling performance of a disk drive and for further decreasing the size of the disk drive. The disk drive is provided with a recording and reproducing unit for recording or reproducing information on a minidisk encased in a disk cartridge, a holder and holding the disk cartridge that is being inserted, a slider capable of transfering the disk cartridge between a mounting and dismounting position and an insertion completed position, drive mechanisms capable of driving the slider, and a chassis that serves as a mounting base for these principal components of the disk drive. The disk drive is constructed of two units of a holder unit obtained by mounting the slider on the holder, and a chassis unit obtained by mounting the recording and reproducing unit and the drive mechanism on the chassis.

Abstract: A disk drive apparatus includes a spindle for engagement with a central hole of a disk hub of a magnetic disk, a rotary member fixed to the spindle, a chucking magnet provided on the rotary member for attracting the disk hub, and a chucking lever pivotally provided on the rotary member which comes at its one end into engagement with a drive hole formed in the disk hub to rotate the disk. When the chucking lever is not chucking the disk, the chucking lever is pivotal about its pivot support point within a given angle, but its movement in the axial direction of the spindle is prevented. The pivot support point section is provided with a disengagement preventive lever which acts in relation to the rotary member to prevent the chucking lever from disengaging from the rotary member.