Hitachi Metals, Ltd.

Hitachi, Ltd.

Hitachi Metals Kiko, Ltd.

Teruo Umehara

Norio Matsumoto

Fumihiko Takahashi

Seiki Takedomi

Saburo Okada

Tsutomu Nakamura

Susumu Nakayama

Katsuaki Kikuchi

Kuninori Imai

Takeji Shiokawa

Masato Itagaki

Yosio Haeda

Fumihiko Kitani

Seiki Taketomi

Hiroyuki Daicho

The arm assembly includes an arm member composed of a rotatable boss member; three or more arm plates each formed from a thin, non-magnetic metal sheet and extending in parallel from one side of the boss member; a coil member fixed to the other side of the boss member such that the coil member is swingable in a magnetic gap; and a suspension member having a front end equipped with a recording/reproducing head and a rear end fixed o a free end of each arm plate; wherein pins projecting from upper and lower surfaces of the boss member are fitted into through-holes of an uppermost arm plate and a lowermost arm plate so that the uppermost and lowermost arm plates are strongly fixed to the boss member, and wherein at least one arm plate disposed between the uppermost and lowermost arm plates is integrally fixed to the boss member with a thermoplastic resin.

Arm assembly and voice coil motor

A movable coil-type actuator including (a) a permanent magnet assembly constituted by a flat permanent magnet and a lower yoke element made of ferromagnetic material, the permanent magnet assembly including a recess in a central portion; (b) an upper yoke element made of a ferromagnetic material, the upper yoke element having such a shape that an edge of the permanent magnet does not extend from a periphery of the upper yoke element when viewed from above; (c) a unitary base member made of a thermoplastic resin and integrally including a hold portion for receiving the permanent magnet assembly and support portions for supporting the upper yoke element, a magnetic gap being defined by the permanent magnet and the upper yoke element; and (d) a movable coil fixed to an end of a swingable arm and movable in the magnetic gap.

Actuator with moveable coil and recording apparatus

A swing-type actuator having: (a) an upper yoke made of a ferromagnetic material, (b) a permanent magnet assembly constituted by a lower yoke made of a ferromagnetic material and opposing the upper yoke and a flat permanent magnet attached to the lower yoke; (c) a base member made of a thermoplastic resin and having a hold portion projecting from an upper surface of the base member for defining a space into which the permanent magnet assembly is received and support portions projecting from an upper surface of the base member for fixing the upper yoke such that there is a magnetic gap between the permanent magnet assembly and the upper yoke, the base member being integrally molded together with the permanent magnet assembly such that the permanent magnet assembly is fixed to the base member inside the hold portion; and (d) a swingable arm having one end adapted to receive a movable coil and the other end to which a function member is fixable, the movable coil being swingable in the magnetic gap.

Swing-type actuator

The swing-type actuator includes (a) a housing comprising a pair of yokes opposing each other and a permanent magnet attached to at least one of the yokes, for defining a magnetic gap therebetween; (b) a swingable arm having one end to which a movable coil is fixed and the other end to which a function member can be attached such that a part of the movable coil is swingable in the magnetic gap; (c) at least one platelike projection having a through-hole and integrally projecting from the swingable arm adjacent movable coil; and (d) a hold member made of a thermoplastic resin and, for the portion encompassing the part of the coil movable through the magnetic gap, having substantially the same thickness as that part of the movable coil, the hold member being molded such that it encompases the outer periphery of the movable coil and embeds the projection, thereby fixing the movable coil to the arm.

A swing-type actuator having (a) a housing including a pair of yokes opposing each other and a permanent magnet attached to at least one of the yokes for defining a magnetic gap therebetween; (b) a swingable arm having one end to which a movable coil is fixed and the other end to which a function member is fixable, such that the movable coil is swingable in the magnetic gap; (c) a hold member formed from injection molded thermoplastic resin, which encompasss a periphery of the movable coil and is integrally fixed to the arm; and (d) a resin coating layer formed on surfaces of the movable coil and the hold member to minimize detachment of mold 'flashes'. Also, surfaces on the arm and adjacent ledge surfaces on the hold member are provided to promote alignment of the parts in the mold and thereby minimizes flash formation. The hold member also can include an integral rib inside the hollow coil and a stopper member to prevent inadvertent contact between lead wires and non-associated terminal pins during molding.

A swing-type actuator has (a) a housing including a pair of yokes and a permanent magnet attached to at least one of the yokes opposing each other for defining a magnetic gap therebetween; and (b) a swingable arm having at one end a hold member encompassing a movable coil, such that the hold member and movable coil have essentially the same thickness and the movable coil is swingable in the magnetic gap, the arm and the hold member being integrally formed of a thermoplastic resin having a longitudinal modulus of 30.times.10.sup.4 kg/cm.sup.2 or more.

A focus magnet having (a) three axially magnetized hollow cylindrical permanent magnets disposed concentrically along a center axis of a cathode ray tube such that their opposite magnetic poles face each other; (b) yokes in the form of hollow discs disposed on both sides of the permanent magnets; (c) a static control coil disposed inside a center permanent magnet; (d) a horizontal dynamic control coil disposed inside one of side permanent magnets; and (e) a vertical dynamic control coil disposed inside the other side permanent magnet, whereby electron beams passing in the cathode ray tube are converged to a small spot diameter.

Focus magnet with separate static and dynamic control coils

In a linear motor having at least one pair of permanent magnet assemblies opposing each other via a gap therebetween, each of the permanent magnet assemblies is constituted by a plurality of permanent magnets, and each of the permanent magnets has, in a plane perpendicular to the moving direction of a movable member, a cross section satisfying the relation: Ac&gt;Ae, wherein Ac represents a cross section in a center portion of the permanent magnet and Ae represents a cross section at each end of the permanent magnet, to obtain a substantially sinusoidal magnetic flux density distribution. Preferably, the permanent magnet has on the side facing the gap a flat center surface and inclined flat surfaces positioned on both sides of the center surface.

Linear motor

A linear motor comprising a center yoke made of a ferromagnetic material; outer yokes made of a ferromagnetic material, having permanent magnets, each having magnetic poles on the inner and outer surfaces thereof and fixed to the inner surface of the outer yokes, and disposed outside the center yoke with both ends thereof being magnetically coupled; and a movable member having coils wound on the outer circumference thereof and axially movably disposed in a gap between the center yoke and the outer yokes, in which recesses are provided on the opposing surfaces of the center yoke and the movable member, and a static-pressure gas bearing is formed by providing an air intake vent connecting to these recesses.

A voice coil-type linear motor comprising an cylindrical outer yoke made of a ferromagnetic material; a cylindrical center yoke made of a ferromagnetic material and magnetically coupled with the outer yoke; an integral, cylindrical magnet consisting essentially of an R-B-Fe alloy wherein R is at least one of rare earth metals such as Nd, Pr and Dy and having magnetic anisotropy in a radial direction, the cylindrical magnet being fixed to an inner surface of the outer yoke; a protective member made of a nonmagnetic and conductive material and fixed to a surface of the cylindrical magnet; and a movable coil means arranged in a magnetic gap between the center yoke and the cylindrical magnet.

Voice coil-type linear motor

A linear motor of moving-coil type is disclosed, in which a multi-phase moving coil includes a plurality of flat coil units each not wider than the longitudinal length of a permanent magnet making up a stationary part divided by the number of coil phases, the flat coil units being arranged successively in the same plane with central parts not adjacently overlaid one on the other. The central parts of the moving flat coil units have a thickness equivalent to a single phase in spite of the multiple phases of the moving coil. Thus a great electromagnetic force is generated, and at the same time a high propulsive force is obtained with the magnetic flux density not reduced in the gap accomodating one phase of coils alone.

Linear motor of moving-coil type

In an electromagnetic drive unit including;

Electromagnetic drive unit

An actuator for use in a pickup device for a video disk plunger having a cylindrical yoke made of a soft magnetic material, a pair of tubular solenoid coils disposed in said yoke such that the same polarity appears at adjacent portions thereof, and a movable element disposed axially movably inside of the tubular solenoid coils, the movable element having an axially magnetized permanent magnet and pole shoes attached to both ends of the permanent magnet. Dampers made of a resilient material such as a butyl rubber are secured to both ends of the yoke. The dampers support projections projected from both ends of the movable element such that the projections project axially outwardly of the dampers. A permanent magnet for magnetically attracting a stylus is secured to the outer end of one of the projections.

Actuator for use in a pickup device for a video disk player

An actuator driven by D.C. power suitable for use in actuating automobile door locking device. The actuator has a yoke apparatus defining a space, two annular solenoid coils supported and received by the yoke apparatus and adapted to be energized simultaneously such that poles of the same polarity appear at the adjacent ends of the coils, and moving means reciprocatably disposed in the space of the yoke apparatus. The moving means includes an axially magnetized permanent magnet carried by a shaft and a pair of magnetic members attached to both axial ends of the permanent magnet.

Growing community of inventors

Hanyu, Japan

Teruo Umehara