Magnet Detail Patents (Class 360/264.9)
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Patent number: 8875386Abstract: An HSA transport comb includes an alignment pin extending from the comb body into a tooling hole of the actuator arm, and a separator finger in contact with a suspension assembly of an HGA with the transport comb in a second angular orientation with respect to the actuator arm, but not in a first angular orientation. The transport comb includes a restraining tower extending into a mass-reduction opening of the actuator arm. The restraining tower includes a first lobe that fits within the mass-reduction opening with the transport comb in the first angular orientation, but not with the transport comb in the second angular orientation. The restraining tower also includes a first neck that fits within the mass-reduction opening with the transport comb in either angular orientation, and has a neck height that is greater than the actuator arm thickness.Type: GrantFiled: March 16, 2012Date of Patent: November 4, 2014Assignee: Western Digital Technologies, Inc.Inventor: Gregory G. Foisy
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Patent number: 8780502Abstract: A voice coil motor for a disk drive unit includes an external magnet and an actuator coil movably located above the external magnet. The external magnet has a main body with a magnetic north pole, a magnetic south pole and a transition surface therebetween, and further has a protrusion extending from the center part of the main body for increasing torque force, thereby improving the performance of the voice coil motor. The invention also discloses a disk drive unit including the same.Type: GrantFiled: July 11, 2011Date of Patent: July 15, 2014Assignee: SAE Magnetics (H.K.) Ltd.Inventors: Daisuke Shirato, Da qing Huang, Huan yin Zhong
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Patent number: 8659851Abstract: A magnetic head is controlled more stably when retracted from above a magnetic disk. When a permanent magnet member 10 having a protrusion projecting from the longer periphery to a side opposite to the center of a fan is mounted on a yoke 15, the end part P side where the sum of thicknesses (P1+P2) is the largest, i.e., the upper face side of a magnet matrix 111 on the protrusion side, is higher than the upper face side of the magnet matrix in the other area. Therefore, since the magnet matrix 111 in the protrusion is located closer to a lock pin 21, the magnetic attraction force between the lock pin 21 and the permanent magnet member 10 becomes stronger, so that the permanent magnet member 10 is locked more firmly when retracted from above the magnetic disk (at the time of locking), whereby the stability can be enhanced.Type: GrantFiled: December 22, 2011Date of Patent: February 25, 2014Assignee: TDK CorporationInventors: Kenichi Yoshida, Shigeya Takahashi, Kazuaki Nawa
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Patent number: 8194358Abstract: A magnet of rectangular prism or parallelepiped prism shape is disposed on a yoke having a triangle shape or a frusto-triangular shape to construct a magnetic circuit for a voice coil motor. The magnetic circuits facilitate positioning and holding of a moving coil, and the voice coil motor is improved in positioning precision of a magnetic head.Type: GrantFiled: March 19, 2008Date of Patent: June 5, 2012Assignee: Shin-Etsu Chemical Co., Ltd.Inventors: Hiroyuki Yamada, Daiki Kato, Keiji Nagamiya
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Publication number: 20120113548Abstract: A magnet of rectangular prism of parallelepiped prism shape is disposed on a yoke having a triangle shape or a frusto-triangular shape to construct a magnetic circuit for a voice coil motor. The magnetic circuits facilitate positioning and holding of a moving coil, and the voice coil motor is improved in positioning precision of a magnetic head.Type: ApplicationFiled: January 12, 2012Publication date: May 10, 2012Inventors: Hiroyuki YAMADA, Daiki Kato, Keiji Nagamiya
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Patent number: 8064171Abstract: Embodiments of the present invention help to reduce out-of-plane excitation force exerted on a coil in a voice coil motor of a magnetic disk drive, so that vibration of a magnetic head is suppressed. According to one embodiment, a voice coil motor has a flat magnet that faces a coil, and generates a magnetic field, and yokes that apply the magnetic field generated by the magnet to the coil. The magnet is provided with a magnetic flux guiding section, absorbing leakage flux from the magnet, on a most distal end of the magnet as viewed from a pivot axis. A most distal part of the coil as viewed from the pivot axis, may be situated in an outer side with respect to the most distal end of the magnet, and the magnetic flux guiding section is provided between the most distal end of the magnet and the most distal part of the coil.Type: GrantFiled: January 16, 2009Date of Patent: November 22, 2011Assignee: Hitachi Global Storage Technologies, Netherlands B.V.Inventors: Toshihiko Shimizu, Keiko Watanabe, Shigeo Nakamura, Noritaka Otake
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Patent number: 7990658Abstract: A voice coil motor for a disk drive includes a permanent magnet, a voice coil adapted to move in an arc proximate to the permanent magnet, a top plate positioned above the voice coil, and a bottom plate positioned below the voice coil. The permanent magnet has two halves that are magnetized in opposite direction. The two halves of the magnet are split into a right half magnet portion and a left half magnet portion. The right half magnet portion and the left half magnet portion are attached to the top plate and the bottom plate respectively at opposite sides of the voice coil motor. The invention also discloses a disk drive unit with such VCM.Type: GrantFiled: August 21, 2007Date of Patent: August 2, 2011Assignee: SAE Magnetics (H.K.) Ltd.Inventors: YanChu Xu, JianFeng Xu, LingJun Kong, Lei Yu, Qiang Zhao
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Patent number: 7855856Abstract: A disk drive includes a magnetic recording medium rotatably supported, a spindle motor for spinning the recording medium, a slider having a head, a supporting arm having the slider at a first end facing the recording medium, a bearing for holding the supporting arm rotatably along a recording surface of the medium and pivotably in a vertical direction with respect to the recording surface, a leaf spring giving thrusting force to a first end of the supporting arm toward the medium, and a driver for rotating the supporting arm along the recording surface. When the driver rotates the supporting arm along the recording surface and parks the head in a given evacuation area on the recording surface, a second end of the supporting arm is depressed.Type: GrantFiled: September 16, 2005Date of Patent: December 21, 2010Assignee: Panasonic CorporationInventor: Hideki Kuwajima
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Publication number: 20100079916Abstract: A low power voice coil motor (VCM) with a guiding magnet shell comprises a magnetic device, a lens carrier, a base, a plurality of guide posts, an electromagnetic driving apparatus and a shell enclosing the lens carrier, the magnetic device and the electromagnetic driving apparatus. The shell and the magnetic device are arranged with a distance within a predetermined range and the attractive force between the magnetic device and the shell in lateral direction induces a shift of the lens carrier for added the friction force between the plurality of guide posts and walls of a plurality of holes. The added friction force is larger than a gravitational force from a total weight of the magnetic device, the lens carrier and a lens set held by the lens carrier, and/or an upward attractive force of the shell on the magnetic device, so the lens set can be fixed at a position even if power is turned off.Type: ApplicationFiled: July 31, 2009Publication date: April 1, 2010Applicant: VASSTEK INTERNATIONAL CORP.Inventor: Shih-Chuan Lee
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Patent number: 7660077Abstract: In an embodiment of the present invention, at least one mechanical fastener is used to mount a voice coil magnet assembly of a hard disk drive on a housing of the hard disk drive. A layer of a material having a low friction coefficient is disposed between the housing and the voice coil magnet assembly.Type: GrantFiled: January 10, 2006Date of Patent: February 9, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Steven Hanssen, Masaki Kohno, Masakazu Sasaki, Jr-Yi Shen
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Patent number: 7652850Abstract: Embodiments of the invention decrease bending vibrations and torsional vibrations of a voice coil generated by off-plane vibrational forces on the voice coil to reduce noise and to enable a large capacity. In one embodiment, a rotating disk type storage unit comprises a rotating disk recording medium, a head that moves radially relative to the rotating disk recording medium to perform recording or reproduction, a turnable actuator having mounted on one side thereof the head, and a voice coil motor to drive the actuator. The voice coil motor comprises a voice coil mounted on the other side end of the actuator, and a magnet arranged in opposition to the voice coil. A magnet outer periphery of the magnet disposed distant from an actuator turning center is formed to be arcuately concave in shape, and the concave-shaped outer periphery intersects the voice coil.Type: GrantFiled: May 17, 2005Date of Patent: January 26, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Kenji Suzuki, Toshihiko Shimizu, Shingo Tsuda, Kouki Uefune
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Patent number: 7609476Abstract: Embodiments of the invention provide a magnetic disk drive whose flexibility in the layout of components is enhanced in spite of the fact that a magnetic disk and a driving section such as the voice coil motor that drives a head arm are isolated from each other. In one embodiment, a magnetic disk drive includes a magnetic disk compartment in which a magnetic disk, a head that reads/writes data from/onto the magnetic disk, and a head arm holding the head are disposed, and a VCM compartment with an internally disposed VCM that pivotally moves the head arm about a pivot shaft. The magnetic disk compartment and the VCM compartment are separated by an isolation wall provided at the bottom of the magnetic disk compartment along the recording surface of the magnetic disk. The pivot shaft is disposed in a penetrating form in an opening.Type: GrantFiled: April 12, 2006Date of Patent: October 27, 2009Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Teruyoshi Higashiya
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Patent number: 7576954Abstract: A symmetric voice coil motor assembly having a central axis and including: a bearing assembly for rotation about the central axis; a coil assembly that is positioned radially outwardly from the bearing assembly and that has at least two pairs of coils and an inner yoke; a permanent magnet set that is positioned radially outwardly from the coil assembly and that includes at least two pairs of ring magnets and an outer yoke; and a head suspension assembly that is connected to the coil assembly and that includes a head gimbal assembly and an arm connected to the head gimbal assembly. The voice coil motor assembly may be a component in a hard disk drive, such as a micro drive.Type: GrantFiled: February 16, 2006Date of Patent: August 18, 2009Assignee: SAE Magnetics H.K. Ltd.Inventors: Liding Wei, Yihua Pei
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Publication number: 20090086377Abstract: Embodiments of the present invention help provide a simple and inexpensive actuator mechanism for a magnetic disk drive. The actuator mechanism includes an approximately circular coil and a simple shaped magnet, and is capable of displaying adequate performance required for the magnetic disk drive. According to one embodiment, the magnetic disk drive includes an actuator mechanism which has an approximately circular coil and an approximately rectangular magnet. The long axis direction of the rectangular magnet is oriented in parallel to a straight line connecting the center of the inner circle of the circular coil in a state in which the actuator is positioned at the outermost circumference of a data area and the center of the inner circle of the circular coil in a state in which the actuator is positioned at the innermost circumference of the data area.Type: ApplicationFiled: September 25, 2008Publication date: April 2, 2009Inventors: Mutsuro Ohta, Masakazu Sasaki, Takeshi Chawanya, Kenji Suzuki
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Publication number: 20090073614Abstract: A voice coil motor has an arm for arcuate movement about a pivot, and a coil at one end of the arm. There is a permanent magnet mounted adjacent the coil. The permanent magnet has only one pole facing, and for operational co-operation with, the coil. The coil has a centre of mass and a geometric centre. The center of mass and the geometric centre are coincident. The coil is mounted to the arm perpendicular to a movement plane of the arm for the arcuate movement.Type: ApplicationFiled: April 26, 2006Publication date: March 19, 2009Inventors: Chao Bi, Quan Jiang, Song Ling
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Patent number: 7497378Abstract: A magnetic stripe reading device including a magnetic head assembly including a mounting element, at least one information reading sensor having output contacts, the sensor being mounted in the mounting element and a flat cable coupled to the output contacts of the at least one information reading sensor, a portion of the flat cable being arranged in a doubled-over configuration over the output contacts, thereby to provide anti-tampering protection to the output contacts.Type: GrantFiled: December 8, 2006Date of Patent: March 3, 2009Assignee: Verifone, Inc.Inventor: Arnon Aviv
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Patent number: 7468867Abstract: An HDD has a carriage which moves a head with respect to a medium, and a voice coil motor (VCM) which drives the carriage. The VCM has a magnet, between which and a first shell formed of a magnetic substance a magnetic circuit is formed, and a voice coil which is secured to the carriage and disposed in a magnetic gap. A depression which receives a projecting portion covering a lead of the voice coil is formed in the first shell, and thereby a projection projecting toward the coil is consequently formed. This structure partially narrows the magnetic gap and allows generation of a torque with sufficient intensity.Type: GrantFiled: July 29, 2005Date of Patent: December 23, 2008Assignee: Kabushiki Kaisha ToshibaInventors: Tomoyuki Tokizaki, Toshikuni Sato, Jun Shimizu
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Patent number: 7420782Abstract: Embodiments of the present invention provide a rotating disk storage device adopting a thin yoke structure. In one embodiment, the yoke structure of a voice coil motor includes a base of a casing formed from a ferromagnetic material; an auxiliary yoke disposed so as to be magnetically coupled to the base; a magnet disposed so as to be magnetically coupled to a front surface of the auxiliary yoke; and a main yoke provided with yoke legs magnetically coupled to the auxiliary yoke and an opposing surface that confronts a front surface of the magnet. In addition, a yoke gap is defined between the opposing surface and the front surface of the magnet. The base and the auxiliary yoke form a magnetic path, which allows a dedicated yoke on a lower portion to be eliminated.Type: GrantFiled: July 16, 2004Date of Patent: September 2, 2008Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Takanori Kawakami, Shinichi Kimura, Hiroki Kitahori, Hiroshi Matsuda
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Patent number: 7414815Abstract: A magnetic disk device comprises a magnetic disk in which a data zone is formed. An actuator has a voice coil and a head slider carrying a magnetic head, the actuator being swung to move the magnetic head over the disk between an innermost position of the data zone and an outermost position of the data zone. A magnet has a magnetization center and is opposed to the voice coil so that a voice coil motor which swings the actuator is formed, the magnet having a north pole and a south pole confronting each other via the magnetization center. The magnetic disk device is provided so that a deviation of a center of the voice coil from the magnetization center when the magnetic head is in the innermost position of the data zone is substantially equal to a deviation of the center of the voice coil from the magnetization center when the magnetic head is in the outermost position of the data zone.Type: GrantFiled: June 27, 2007Date of Patent: August 19, 2008Assignee: Fujitsu LimitedInventors: Shinji Fujimoto, Masato Shibuya, Hisashi Kaneko, Tsuneyori Ino, Yukihiro Komura, Mitsuhiro Izumi, Kei Funabashi
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Patent number: 7298592Abstract: Provided is an actuator of a disk drive to move a read/write head, for recording and reproducing data, to a predetermined position on a disk. The actuator includes an actuator pivot installed on a base member of the disk drive, a swing arm that is rotatably coupled to the actuator pivot and has a suspension supporting the head at a leading end portion of the swing arm, a coil support portion provided at a rear end portion of the swing arm, a VCM coil coupled to the coil support portion and having four sections having respective particular directions, and magnets arranged to face the VCM coil and having four poles respectively corresponding to the four sections of the VCM coil.Type: GrantFiled: May 27, 2004Date of Patent: November 20, 2007Assignee: Samsung Electronics Co., Ltd.Inventors: Haeng-soo Lee, Seong-woo Kang, Young-hoon Kim
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Patent number: 7275303Abstract: The upper voice coil motor magnet assembly (64a?) of a disk drive (10?) is magnetically aligned with the lower voice coil motor magnet assembly (64b?) using an alignment fixture (126). The alignment fixture (126) engages the upper voice coil motor magnet assembly (64a?) and lifts the same into a suspended position above the lower voice coil motor magnet assembly (64b?). In this suspended condition, the alignment fixture (126) allows the magnetic field to move the upper voice coil motor magnet assembly (64a?) within the horizontal dimension to a magnetically aligned position with the lower voice coil motor magnet assembly (64b?). Thereafter, the alignment fixture (126) lowers the upper voice coil motor magnet assembly (64a?) to a position where the same is again supported above the lower voice coil motor magnet assembly (64b?).Type: GrantFiled: December 15, 2003Date of Patent: October 2, 2007Assignee: Maxtor CorporationInventor: Richard F. O'Day
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Patent number: 7262939Abstract: A top pole piece of a voice coil motor (VCM) is attached to a hard disk drive cover without screw fasteners and with minimal loss of VCM magnetic flux capacity. A pair of leaf springs are supported at both ends, rather than by cantilever, to more uniformly distribute mechanical stress throughout the springs so that less space is required to achieve the same transverse load as a cantilevered spring of the same profile. The smaller space envelope required by this design minimizes the loss of magnetic flux capacity of the VCM. Each leaf spring has two integral legs, central portions of which are rigidly fastened to the drive cover. The end of each leg opposite the central portion applies a force against the cover in the assembled disk drive.Type: GrantFiled: July 30, 2004Date of Patent: August 28, 2007Assignee: Hitachi Global Storage Technologies Netherlands, BVInventors: Michael Robert Hatchett, Daniel Robert Stacer
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Patent number: 6816343Abstract: A disk drive includes a magnetic element and a coil. The magnetic element includes an inner magnet set including first and second inner magnets. The magnetic element further includes an outer magnet set including first and second outer magnets. The first outer magnet is circumferentially disposed along the first inner magnet. The second outer magnet is circumferentially disposed along the second inner magnet. The coil is attached to a coil support of an actuator and disposed overlapping within a magnet periphery of the magnetic element. The coil includes an inner segment, an outer segment, and a pair of side segments electrically connecting the inner and outer segments. The inner segment is disposed overlapping with the inner magnet set, the outer segment being disposed overlapping with the outer magnet set. Each of the side segments is disposed equally overlapping with the inner and outer magnet sets.Type: GrantFiled: January 31, 2003Date of Patent: November 9, 2004Assignee: Western Digital Technologies, Inc.Inventor: Kamran Oveyssi
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Patent number: 6816342Abstract: A disk drive includes a magnetic element having an inner magnet and an outer magnet. The disk drive further includes a first coil. The first coil includes a first coil inner segment, a first coil outer segment, and a first coil radial segment disposed generally perpendicular to the first coil inner segment and the first coil outer segment. The first coil radial segment overlaps the inner and outer magnets within a magnet periphery throughout a fill range of motion of the actuator. The disk drive further includes a second coil. The second coil includes a second coil inner segment, a second coil outer segment, and a second coil radial segment disposed generally parallel to the first coil radial segment. The second coil radial segment overlaps the inner and outer magnets within the magnet periphery throughout the full range of motion of the actuator.Type: GrantFiled: January 31, 2003Date of Patent: November 9, 2004Assignee: Western Digital Technologies, Inc.Inventor: Kamran Oveyssi
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Patent number: 6768977Abstract: A circuit model (50) for use in analyzing a VCM circuit has a first resistor (62), a first inductor (64), a second inductor (58), and a voltage source (60), in series modeling, respectively, a VCM inductor, a winding leakage inductance of the VCM inductor, a VCM inductor resistance, and a BEMF voltage generated across the VCM inductor when the input nodes are open circuited. An input capacitor (56) interconnects the input terminals (52,54) to model an equivalent capacitance of the VCM inductor. Third and fourth inductors (32,34) and a second resistor (36) are connected in a first series loop (28) inductively coupled to the second inductor (58) to model, respectively, an inductance of the top VCM magnet plate, the leakage inductance of the top VCM magnet plate, and a resistance of the top VCM magnet plate.Type: GrantFiled: November 30, 1999Date of Patent: July 27, 2004Assignee: Texas Instruments IncorporatedInventor: Tan Du
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Patent number: 6735054Abstract: The present invention relates to a low cost voice coil motor for use in a disc drive. In accordance with one embodiment of the invention, the voice coil motor includes at least one overmold encapsulating an assembly of a magnet and a pole. The overmold thus provides a barrier against outgassing and corrosion.Type: GrantFiled: June 20, 2001Date of Patent: May 11, 2004Assignee: Seagate Technology LLCInventors: Tak Koon Ooi, Jierapipatanakul Niroot, Wai Onn Chee
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Patent number: 6710981Abstract: A disk drive includes a voice coil motor (VCM) having a narrow coil angle and a magnet magnetized with two or three pole pairs. The VCM magnet may define first, second and third sections, the second section being magnetically polarized in an axial direction that is opposite to that of the first and third sections. The first radial leg of the VCM coil faces the second section and the second radial leg faces the third section when the head is positioned at a non-operational position. The first radial leg faces the first section and the second radial leg faces the second section when the head is reading and/or writing to the data portion of the disk. Alternatively, the VCM magnet defines first and second sections that are magnetized in opposite axial directions.Type: GrantFiled: July 31, 2002Date of Patent: March 23, 2004Assignee: Western Digital Technologies, Inc.Inventors: Kamran Oveyssi, Chunjer C. Cheng
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Patent number: 6664663Abstract: An interlocking assembly of a voice coil motor for a hard disk drive having an arcuate shaped hollow structure formed by metal injection molding. The hollow structure has a bottom plate member that is separated from a top plate member by a pair of upright members disposed therebetween. The upright members joined with the inside surfaces of the plate members. The uprights are disposed at each end of the hollow structure. A tapered recess is formed in the top surface of the bottom plate, the recess ingress's from a convex edge of the bottom plate and narrows while extending through to an opposite concave edge, the tapered recess has side edges shaped to tightly interlock with a flat arcuate shaped permanent magnet having dovetail side edges to slidely interlock with the tapered recess of the bottom plate of the hollow structure, thus eliminating the need for adhesive fastening.Type: GrantFiled: November 27, 2000Date of Patent: December 16, 2003Assignee: Advanced Materials Technologies Pte. Ltd.Inventor: Chee Tian Yeo
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Patent number: 6633457Abstract: An actuator assembly for positioning read/write heads above a data storage media comprises a pivotally mounted carriage arm assembly with a voice coil and a magnetic device having a plurality of poles for generating a magnetic field. The voice coil is positioned with its effective portions crossing through the magnetic field to generate at least one pair of driving forces in a direction substantially orthogonal to a seeking direction of the read/write heads. The carriage arm driven by said pair of forces has substantially no reacting force generated onto the pivot so that the servo bandwidth of the head positioning assembly can be improved and achieves a high degree of head positioning accuracy.Type: GrantFiled: July 25, 2000Date of Patent: October 14, 2003Assignee: Data Storage InstituteInventors: Huai Lin, Teck Seng Low, Zhimin He, Shixin Chen, Qinghua Li
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Patent number: 6606223Abstract: A voice coil motor assembly in a disc drive includes first and second pole pieces held in spaced relationship to one another such that a gap is defined therebetween. A permanent magnet is located on the first pole piece within the gap and a dummy magnet is located on the second pole piece across the gap from the permanent magnet. The first and second pole pieces, together with the magnet and the dummy magnet, form a magnetic circuit conducting lines of magnetic flux within the voice coil motor and across the gap. The dummy magnet acts to encourage magnetic flux to flow across the gap in a manner such that the roll and pitch torque constants of the voice coil motor are reduced.Type: GrantFiled: April 17, 2001Date of Patent: August 12, 2003Assignee: Seagate Technology LLCInventors: Tak Koon Ooi, Choon Kiat Lim, Chor Shan Cheng, Yi Ren Hong
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Patent number: 6577474Abstract: The present invention relates to a integrated voice coil motor assembly in a head disc assembly of a disc drive, the head disc assembly having a base plate and the top cover enclosing a data storage disc rotatably mounted on a drive motor, and an actuator arm for transferring data to and from the disc. The voice coil motor has a bottom pole attached to the base plate and a top pole integrated with the top cover. A permanent magnet set is positioned between the bottom pole and a top cover and generates a magnetic field between the bottom pole and the top cover. The top pole rests within a recess in an outer surface of the top cover above the bottom pole and provides a return path for the magnetic field generated by the permanent magnet set. A voice coil is attached to the actuator arm and positioned within the magnetic field between the bottom pole and the top cover.Type: GrantFiled: November 29, 2000Date of Patent: June 10, 2003Assignee: Seagate Technology LLCInventors: Frederick Frank Kazmierczak, Michael Alan Maiers
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Patent number: 6549381Abstract: A disk drive includes a disk having a recording surface and a head stack assembly that includes an actuator body; an actuator arm cantilevered from the actuator body and including a head for reading and writing on the recording surface; a coil cantilevered from the actuator body in an opposite direction from the actuator arm, the coil defining a first leg and a second leg and a damping magnet disposed between the first and second legs. The damping magnet is configured to exert a damping force on the head stack assembly that is greater when the head is at a predetermined non-operational position than when the head is over the recording surface.Type: GrantFiled: October 23, 2001Date of Patent: April 15, 2003Assignee: Western Digital Technologies, Inc.Inventor: Scott E. Watson
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Publication number: 20020181159Abstract: A voice coil motor assembly in a disc drive includes first and second pole pieces held in spaced relationship to one another such that a gap is defined therebetween. A permanent magnet is located on the first pole piece within the gap and a dummy magnet is located on the second pole piece across the gap from the permanent magnet. The first and second pole pieces, together with the magnet and the dummy magnet, form a magnetic circuit conducting lines of magnetic flux within the voice coil motor and across the gap. The dummy magnet acts to encourage magnetic flux to flow across the gap in a manner such that the roll and pitch torque constants of the voice coil motor are reduced.Type: ApplicationFiled: April 17, 2001Publication date: December 5, 2002Inventors: Tak Koon Ooi, Choon Kiat Lim, Chor Shan Cheng, Yi Ren Hong
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Patent number: 6411474Abstract: A servo positioned carriage and actuator assembly in which a part of the carriage is positioned within the central portion of the motor. The motor, typically a voice coil motor, includes a coil of electrically conductive windings and a magnet or magnets adjacent to the coil. In one embodiment of the invention, the central portion of the motor is defined by a perimeter of the magnets and the carriage is positioned at least partially inside this perimeter. The carriage, for example, will typically include a ring shaped center portion in which the coil is mounted. This ring shaped center portion mounting the coil is positioned inside the magnets to help minimize the overall mass of the carriage elements of the assembly.Type: GrantFiled: June 22, 1998Date of Patent: June 25, 2002Assignee: Hewlett-Packard Co.Inventor: James C. Anderson
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Publication number: 20020063998Abstract: The present invention relates to a integrated voice coil motor assembly in a head disc assembly of a disc drive, the head disc assembly having a base plate and the top cover enclosing a data storage disc rotatably mounted on a drive motor, and an actuator arm for transferring data to and from the disc. The voice coil motor has a bottom pole attached to the base plate and a top pole integrated with the top cover. A permanent magnet set is positioned between the bottom pole and a top cover and generates a magnetic field between the bottom pole and the top cover. The top pole rests within a recess in an outer surface of the top cover above the bottom pole and provides a return path for the magnetic field generated by the permanent magnet set. A voice coil is attached to the actuator arm and positioned within the magnetic field between the bottom pole and the top cover.Type: ApplicationFiled: November 29, 2000Publication date: May 30, 2002Applicant: Seagate Technology LLCInventors: Frederick Frank Kazmierczak, Michael Alan Maiers
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Patent number: 6392845Abstract: A stator magnet according to a first embodiment of the present invention forms a voice coil motor with a closed coil. The closed coil is supported by an actuator arm in a rotatable manner and at a predetermined rotation angle. The closed coil has first and second side edges that extend along different lines in radial directions whose center is a center of rotation of the actuator arm. It also has an outer edge that connects edges of outer sides of the first and second side edges with viewed from the radial direction, and extends along an arc whose center is the center of rotation. A first magnetic pole region is located within a moving area of the first side edge to act on the first side edge. A second magnetic pole region is located within a moving area of the second side edge to act on the second side edge. The polarity of the second magnetic pole region is opposite to the polarity of the first magnetic pole region.Type: GrantFiled: June 30, 2000Date of Patent: May 21, 2002Assignee: International Business Machines CorporationInventors: Shingo Tsuda, Eiji Soga, Kiyoshi Satoh, Fu-Ying Huang, Tetsuo Senba
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Publication number: 20020015263Abstract: The present invention relates to a low cost voice coil motor for use in a disc drive. In accordance with one embodiment of the invention, the voice coil motor includes at least one overmold encapsulating an assembly of a magnet and a pole. The overmold thus provides a barrier against outgassing and corrosion.Type: ApplicationFiled: June 20, 2001Publication date: February 7, 2002Inventors: Tak Koon Ooi, Jierapipatanakul Niroot, Wai Onn Chee
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Patent number: 6252744Abstract: Embodiments of the instant invention are directed to a head parking assembly for a disc drive assembly. In preferred embodiments, the head parking assembly comprises a voice coil motor and a non-contacting magnetic latch mechanism, wherein the voice coil motor comprises a plurality of backirons, a plurality of permanent magnets, a coil, a conductive standoff and a nonconductive standoff. The permanent magnets are disposed on the backirons and the standoffs reside at opposite ends of the backirons being disposed substantially perpendicularly thereto. The coil is located in the gap between the permanent magnets, such that when an electric field is passed through the coil, the resulting magnetic field in the coil operates in conjunction with the magnetic fields of the permanent magnets to control the movement of the head across the disc.Type: GrantFiled: March 1, 1999Date of Patent: June 26, 2001Assignee: Seagate Technology LLCInventor: Andrew Kelemen
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Patent number: 6175469Abstract: A damper for dampening resonance created by a voice coil motor of a disc drive and transmitted to a supporting enclosure, the resonance capable of creating noise signals to the disc drive servo control system. The damper has a dampening member and a liner, the liner being a magnetically permeable member that is magnetically attracted to the voice coil motor and thereby pressingly engaging a magnet housing of the voice coil motor. In a preferred embodiment the dampening member is an acrylic polymer. In an alternative embodiment the dampening member is a fluoroelastomer. The magnet housing has characteristic features that increase the magnetic flux to the liner.Type: GrantFiled: December 4, 1998Date of Patent: January 16, 2001Assignee: Seagate Technology, Inc.Inventors: Mohammad N. Ahmad, Kenneth L. Pottebaum, Ryan T. Ratliff