With Flux Leakage-reducing Means Patents (Class 335/304)
  • Patent number: 5119057
    Abstract: A permanent magnet structure having at least one loop of circulating flux comprises a first and second plurality of uniformly magnetized prismatic magnetic material sections forming a polygonal shaped cavity and having a point F positioned along a zero equipotential base line joining two vertices within the cavity, that point being the reference for a figure of merit M corresponding to a maximum field strength and a minimum ratio of the value of the area of magnetized material to the area of the cavity. The first plurality of sections totally define the cavity and have their respective remanences aligned to result in a flux passing orthogonally through the base line. The second plurality of section is oriented with respect to their respective remanences and the first sections so as to confine the flux within the cavity. A third plurality of nonmagnetized magnetic sections encloses the base line and borders the first sections for providing an inductive path to channel the flux and close the loop.
    Type: Grant
    Filed: October 19, 1989
    Date of Patent: June 2, 1992
    Assignee: New York University
    Inventor: Manlio G. Abele
  • Patent number: 5109172
    Abstract: A dc electric motor having a rotor, a stator, and at least a pair of oppositely disposed main magnets associated with one of the rotor and stator is provided. Preferably, the main magnets are associated with the stator in a stator assembly. The stator assembly also includes interpolar diverting magnets positioned on each side of each main magnet. Additionally, an end diverting magnet assembly including at least a pair of oppositely disposed end diverting magnets may be positioned at at least one end of the stator assembly. Each of the interpolar diverting magnets and end diverting magnets have a magnetic field perpendicular to the magnetic field of the main magnets and are oriented to increase the flux density of the main magnets with low magnetic leakage.
    Type: Grant
    Filed: April 26, 1990
    Date of Patent: April 28, 1992
    Inventor: Sang H. L. Pace
  • Patent number: 5107239
    Abstract: Magnetized transition elements are provided between the magnetized elements that define the cavity of the structure. The magnitudes and directions of the fields of these transition elements are arranged so that the external boundary of the transition elements are equipotential surfaces, and the induction in the transition elements is zero. Separate return yokes are provided for the magnetized elements adjacent the transition elements, that do not contact the transition elements.
    Type: Grant
    Filed: May 30, 1991
    Date of Patent: April 21, 1992
    Assignee: New York University
    Inventor: Manlio G. Abele
  • Patent number: 5107238
    Abstract: Periodic permanent magnet (PPM) stacks for use in wigglers and traveling e tubes having magnetic cladding. A variable magnetic potential cladding along the adjacent surfaces of working magnets is used, thereby increasing the efficient use of magnetic material and increasing the magnetic field while minimizing weight. The magnetic cladding has a direction of polarity perpendicular to the direction of polarity of the working magnets. Extraneous magnetic fields are also reduced. A magnetic shunt, or soft iron, is used to facilitate the conduction of magnetic flux and create an equal magnetic potential exterior surface.
    Type: Grant
    Filed: April 1, 1991
    Date of Patent: April 21, 1992
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Herbert A. Leupold
  • Patent number: 5099217
    Abstract: A cladded magnet twister device for a microwave/millimeter wave source is comprised of a plurality of polygonal similarly magnetized magnet segments. Each magnet segment is displaced radially in equal angular segments along the central axis relative to its neighboring segment to provide a transverse helical field and is comprised of a relatively short length of an array of bar magnets, cladding magnets, bucking magnets, pole pieces and corner pieces. The pole pieces are secured to the ends of the bar magnets and have convex faces which are directed inwardly toward one another.
    Type: Grant
    Filed: September 16, 1991
    Date of Patent: March 24, 1992
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Herbert A. Leupold
  • Patent number: 5089798
    Abstract: Two disc shaped permanent magnets are provided within a yoke structure in a manner to face one another. Two pole pieces are disposed on the surfaces of the two magnets respectively. Small spherical metallic members which induce a localized increase in magnetic field strength, are attached to the surfaces of the opposed pole pieces at selected locations in a manner which unifies the magnetic field produced.
    Type: Grant
    Filed: December 13, 1990
    Date of Patent: February 18, 1992
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventor: Koji Miyata
  • Patent number: 5084690
    Abstract: An improved permanent magnet solenoid having a stepped transition in axial agnetic field profile and comprised of two permanent magnet solenoids, with appropriate cladding, placed in tandem and a radially magnetized ring magnet placed within the working cavity of the solenoids at the joint of entire structure.
    Type: Grant
    Filed: April 29, 1991
    Date of Patent: January 28, 1992
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Herbert A. Leupold
  • Patent number: 5063934
    Abstract: A permanent magnet assembly used for creating a uniform magnetic field across a portion of an air gap has a permanent magnet grouping, including a first, principal magnet, a pole piece contacting said principal magnet, and a set of auxiliary magnets extending about the periphery of the pole piece. Two such magnet groupings are positioned within a test chamber, separated a spacer, with the magnet groupings and the chamber defining the air gap across which the magnetic field extends. The strength and uniformity of the magnetic field is adjusted by including a second set of auxiliary permanent magnets or a set of electromagnetic shim coils positioned within the air gap surrounding and overtapping a portion of the air gap. Further adjustment of the magnetic field is accomplished shaping the front surfaces of the pole pieces, thus affecting the shape and direction of the resulting magnetic field.
    Type: Grant
    Filed: November 29, 1988
    Date of Patent: November 12, 1991
    Assignee: Advanced Techtronics, Inc.
    Inventors: Uri Rapoport, Richard Panosh
  • Patent number: 5063368
    Abstract: A magnetic assembly adapted to be secured to a fuel line of a motor vehicle for improving the combustion of the fuel passing through the line by disposing the fuel line within a strong concentrated magnetic field without magnetizing portions of the engine proximate the assembly. The assembly comprises a housing, four primary magnets disposed within the housing and arranged in two adjacent columns of two magnets in each column with the south poles of each magnet facing toward the wall of the housing adapted to be disposed adjacent the fuel line, a plate disposed within the housing against the north poles of the two uppermost primary magnets in each column, and four secondary magnets disposed against the plate on the opposite side thereof from the primary magnets.
    Type: Grant
    Filed: December 18, 1990
    Date of Patent: November 5, 1991
    Inventor: Reza Ettehadieh
  • Patent number: 5055812
    Abstract: A permanent magnet structure comprising a longitudinally extending flux sce fabricated of magnetically rigid material. The flux source comprises a central cavity with a magnetic field being produced therein. Magnetic dipoles having predetermined magnitude and orientation for compensating nonuniformities in the magnetic field are symmetrically located within the plane of the flux source.
    Type: Grant
    Filed: September 24, 1990
    Date of Patent: October 8, 1991
    Assignee: The United States of America as represented by the Secretary of the Army.
    Inventors: Manlio G. Abele, Ramesh Chandra, Henry Rusinek, Ernest Potenziani, II, Herbert A. Leupold
  • Patent number: 5034715
    Abstract: A magnetic structure fabricated of magnetically rigid materials combines a adial magnetic field source with an axial magnetic field source to produce a conical field source. The radial magnetic field source typically comprises a substantially annular enclosed cavity with an internal magnetic field oriented perpendicular to the annular axis of the cavity. The axial magnetic field source most likely comprises a substantially cylindrical enclosed cavity with an internal magnetic field oriented parallel to the cylindrical axis of the cavity.
    Type: Grant
    Filed: November 14, 1989
    Date of Patent: July 23, 1991
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Herbert A. Leupold, Ernest Potenziani, II
  • Patent number: 5003276
    Abstract: Ferromagnetic pieces are mounted on a plurality of nonmagnetic radial rods located at desired locations parallel to a pole face of a permanent magnet used in a magnetic resonance imaging apparatus. The pieces comprise plates which are translatable radially along each rod. Each rod carrying the plates are each rotatable about the rod axis to produce an error field cancelling environmentally induced, low order perturbations. A method for accomplishing same is also included. In a preferred embodiment, the plates are mounted on radial rods positioned at equal angles from one another, preferably thirty degrees (30.degree.) apart and arranged as spokes of a wheel.
    Type: Grant
    Filed: August 11, 1989
    Date of Patent: March 26, 1991
    Assignee: General Atomics
    Inventors: Raymond E. Sarwinski, Bruce C. Breneman
  • Patent number: 4953555
    Abstract: A nuclear magnetic resonance device for use in diagnostic procedures on the uman body is provided and comprises longitudinally extending cylindrical or rectangular crossectioned rare earths permanent magnets provided with cladding magnets extending longitudinally therewith and providing flux control for the establishment of a uniform flux field. Bucking magnets and other supplemental magnetic elements are provided to as precisely as possible control the magnetic flux field effected for the diagnostic procedures.
    Type: Grant
    Filed: October 12, 1989
    Date of Patent: September 4, 1990
    Assignee: The United States of Americas as represented by the Secretary of the Army
    Inventors: Herbert A. Leupold, Ernest Potenziani, II
  • Patent number: 4912445
    Abstract: An electromagnet comprising a magnetic field coil and a substantially cylindrical magnetic shield coaxially disposed around the field coil for defining a magnetic circuit therearound. The magnetic shield comprises a hollow cylindrical magnetic yoke with ring-shaped end plates at its opposite ends. The magnetic yoke's cylindrical wall has a cross-sectional area effective for accommodating the magnetic flux generated by the magnetic field coil. The magnetic yoke has a pair of thicker wall sections at first diametrically opposite positions, and a pair of thinner wall sections a second diametrically opposite positions separated by 90 degrees from the first diametrically opposite positions. The thicker and the thinner wall sections are thicker and thinner, respectively, than a mean required wall thickness which is a wall thickness necessary for providing to the magnetic yoke a cross-sectional area for effectively accommodating the magnetic flux generated by the magnetic field coil.
    Type: Grant
    Filed: January 19, 1989
    Date of Patent: March 27, 1990
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Akinori Yamasaki, Tatsuya Oue
  • Patent number: 4907346
    Abstract: A terrestrial magnetic sensor has a bobbin body having a magnetic core inserting groove, a silicon gel filled in the magnetic core inserting groove, a magnetic core buried in the silicon gel filled in the magnetic core inserting groove, and a bobbin cover for closing the magnetic core inserting groove of the bobbin body. Thus, this terrestrial magnetic sensor can suppress the decrease in the magnetic permeability by burying a magnetic core in a silicon gel and can be hardly affected by the influences of the variations in an environmental temperature and an external stress.
    Type: Grant
    Filed: December 7, 1987
    Date of Patent: March 13, 1990
    Assignee: Alps Electric Co., Ltd.
    Inventor: Yasuaki Watanabe
  • Patent number: 4890083
    Abstract: A shield for electromagnetic radiations comprising a laminated sheet having exterior layers of copper which sandwich an interior layer of a ferromagnetic alloy taken from the class consisting of nickel-iron compounds having from about 42 to about 80 percent nickel by weight and iron as a substantial portion of the remaining material. The layers are metallurgically bonded to each other by sintering or the like. According to a second embodiment, a laminated sheet is provided having exterior layers of copper which sandwich plural interior layers of ferromagnetic material, the layers of ferromagnetic material having progressively higher permeability and being capable of shielding interference of progressively lower energy level when travelling in a direction away from the direction of the source of interference. A typical laminated sheet in the direction away from the source of interference is copper/permendur/80/copper.
    Type: Grant
    Filed: October 20, 1988
    Date of Patent: December 26, 1989
    Assignee: Texas Instruments Incorporated
    Inventors: George Trenkler, Richard G. Delagi, Francois A. Padovani, Donald L. Winslow
  • Patent number: 4869811
    Abstract: A drum-like rotor having numerous, closely spaced, elongated rows formed of permanent magnets arranged end-to-end and secured to the outer surface of the rotor, produces a high-density, rapidly reversing magnetic field in a band-like zone which is spaced a short distance from, and extends along the length of, the rotor outer surface. The magnetic field induces eddy currents in pieces of different metals passed through the zone which produces repulsive magnetic forces of different intensities in different metal pieces, and thus, magnetically separates such pieces. The rows of magnets, in their radial direction, are alternatingly thicker and thinner, so that the outer surface of the thinner rows are depressed relative to their adjacent thicker rows. The outer surface of the magnets of each thicker row have a polarity which is opposite to the polarity of their next adjacent thicker row magnets, and the direction of the magnetic polarity of the magnets of the thicker rows are radial relative to the rotor.
    Type: Grant
    Filed: July 5, 1988
    Date of Patent: September 26, 1989
    Assignee: Huron Valley Steel Corporation
    Inventors: Richard B. Wolanski, Richard R. Osterberg
  • Patent number: 4843357
    Abstract: A tetrahedral junction waveguide switch is provided having two axially juxtaposed sections of hollow rectangular waveguide which are mutually cross-polarized by being rotated 90 degrees with respect to each other. A rod of a ferrite material having gyromagnetic properties is axially disposed within the juxtaposed ends of the waveguide sections and is selectively axially magnetized to control transmission of RF electromagnetic wave energy through the sections. A permanent magnet structure having a unique cladding arrangement which minimizes flux leakage and produces a magnet of high coercive force is employed to produce a unidirectional magnetic bias field along the longitudinal axis of the rod to keep the switch in a low loss transmission state by virtue of Reggia-Spencer effect signal rotation. A selectively operable helical coil is utilized to produce another axial magnetic field which nullifies the bias magnetic field when it is desired to place the switch in a high loss or cut-off transmission state.
    Type: Grant
    Filed: October 20, 1988
    Date of Patent: June 27, 1989
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Richard A. Stern, Herbert A. Leupold
  • Patent number: 4839059
    Abstract: A linear array of clad truncated magic ring segments. Each segment has an entrance and exit hole in its respective cladding magnets. The individual segments are arranged to provide a periodic permanent magnet structure suitable for use in a wiggler or a twister.
    Type: Grant
    Filed: June 23, 1988
    Date of Patent: June 13, 1989
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Herbert A. Leupold
  • Patent number: 4837542
    Abstract: A hollow spherical flux source produces a uniform high-field in its central cavity. The sphere is comprised of a selected magnetic material whose magnetization is aximuthally symmetrical. The magnetic orientation (.alpha.) in the spherical permanent magnet shell is given by the equation:.alpha.=z.theta.where .theta. is the polar angle.
    Type: Grant
    Filed: May 27, 1988
    Date of Patent: June 6, 1989
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Herbert A. Leupold
  • Patent number: 4835470
    Abstract: A magnetizer for magnetographic inspection of articles comprises a main electromagnet, an auxiliary electromagnet, and a power supply unit for the windings of the electromagnets. The auxiliary electromagnet is offset with respect to the central zone of the magnetic field established by the main electromagnet, in a direction perpendicular to that of the magnetic lines of force of the main electromagnet, and is mounted for changing its position.
    Type: Grant
    Filed: February 25, 1987
    Date of Patent: May 30, 1989
    Assignee: Belorussky Politekhnitchesky Institute
    Inventors: Alexei E. Novikov, Leonid A. Putan, Valery I. Meerovich, Anatoly N. Semizelnikov, Vladimir P. Pokatilov
  • Patent number: 4835506
    Abstract: A hollow hemispherical flux source produces a uniform high-field in its central cavity. The hemisphere is comprised of a selected magnetic material whose magnetization is azimuthally symmetrical. The magnetic orientation (.alpha.) in the hemispherical permanent magnet shell is given by the equation:.alpha.=2.theta.where .theta. is the polar angle. A planar plate of high saturation, high permeability material closes the open end of the hemisphere. An axial bore hole through the hemisphere and/or through the planar plate provides the requisite accessability.
    Type: Grant
    Filed: May 27, 1988
    Date of Patent: May 30, 1989
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Herbert A. Leupold
  • Patent number: 4829261
    Abstract: A traveling wave type amplifier. The device features a pair of short helical input and output couplers through which an electron beam is projected. Application of an RF signal to the couplers serves to modulate the electron beam. A drift tube to be positioned between the couplers is dimensioned to attenuate the RF signal while permitting the modulated electron beam to pass through. An amplified output signal is extracted from the output helix. Gain of the tube is enhanced by a linearly decreasing magnetic focussing field.
    Type: Grant
    Filed: December 8, 1987
    Date of Patent: May 9, 1989
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Charles M. DeSantis, Louis J. Jasper, Jr.
  • Patent number: 4822772
    Abstract: A unitary superconducting electromagnetic structure (10) and method of forming same for use particularly at magnetic intensities greater than the magnetic saturation of iron and including an inner body (12) containing a coil pack (40) and an outer magnetic iron body (16) about the inner body (12) in concentric relation thereto. The outer body (16) has an end assembly (18) adjacent each end of the inner body (16) and the outer iron body (16) increases the magnetic field intensity at intensities substantially above the saturation of the magnetic iron in the outer body (16).The design of the electromagnetic structure (10) is based on a computer program which utilizes accurate information concerning the mechanical, thermal, electrical and magnetic properties of the materials proposed for the electromagnet including particularly the thermal and magnetic properties of the iron for predicting precisely the magnetic permeability of the iron at all values of the magnetic field.
    Type: Grant
    Filed: August 14, 1987
    Date of Patent: April 18, 1989
    Assignee: Houston Area Research Center
    Inventor: Frederick R. Huson
  • Patent number: 4818966
    Abstract: A magnetic field-generating device includes a pair of permanent magnet components disposed in such a manner as to face each other with a gap formed therebetween, a yoke for magnetically coupling the pair of permanent magnet components, and pole pieces which are each fixed to a surface of a corresponding permanent magnet component that faces the gap. The magnetic field generating device is adpated to generate a magnetic field in the gap. Each of the pole pieces is made of a laminate of magnetic plates which laminated in a direction substantially perpendicular to the sides of the solid care portion.
    Type: Grant
    Filed: March 28, 1988
    Date of Patent: April 4, 1989
    Assignee: Sumitomo Special Metal Co., Ltd.
    Inventors: Toshinobu Miyamoto, Hideya Sakurai, Hirofumi Takabayashi
  • Patent number: 4816796
    Abstract: In a permanent magnet device, a pair of pole pieces of a ferromagnetic material are disposed opposite to each other, and, in order to generate a homogeneous magnetic field in a gap space between the pole pieces, a pair of members of a permanent magnet material magnetized in a direction substantially orthogonal to the direction of the magnetic field and also magnetized in directions opposite to each other in themselves are disposed adjacent to the pole pieces and symmetrical with each other respectively.
    Type: Grant
    Filed: October 2, 1987
    Date of Patent: March 28, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Goh Miyajima, Takao Takahashi
  • Patent number: 4810986
    Abstract: Truncated clad magnetic structures producing a strong magnetic field within an interior working space and having minimal external flux leakage. Cladding magnets are added to structures which otherwise must be theoretically infinite. The cladding magnets, specially shaped so that their exterior surfaces are at zero magnetomotive potential, permit the use of truncated structures without loss of field strength or uniformity. Cladding formulas give approximate values which can be made more nearly exact by successive approximations in cladding thickness variations.
    Type: Grant
    Filed: February 26, 1988
    Date of Patent: March 7, 1989
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Herbert A. Leupold
  • Patent number: 4808957
    Abstract: A magnetic shield apparatus for shielding against magnetic leakage escaping from a cylindrical magnet unit having a columnar cavity, for generating a static magnetic field along the axial direction of the cavity, has a plurality of magnetic shield members which shield against magnetic leakage escaping from the magnet unit. The magnetic shield members are sequentially joined, with the joint portions of the magnetic shield members extending along the axial direction of the cavity, so as to surround the magnet unit. Casters are attached to each magnetic shield member. The magnetic shield members are fixed by bolts or the like so as to surround the magnet unit.
    Type: Grant
    Filed: June 8, 1988
    Date of Patent: February 28, 1989
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Hiroshi Furukawa
  • Patent number: 4806894
    Abstract: A leakage magnetic field cancelling apparatus comprises a magnetic field generating apparatus and a cancelling coil arranged around the magnetic field generating apparatus. By allowing a direct current to flow through the coil, a magnetic field is generated therefrom. The leakage magnetic field generated from the magnetic field generating apparatus is cancelled or controlled by the magnetic field generated from the coil. Thus, the cancelling apparatus can be realized by a cheap and light coil made of a copper wire or the like.
    Type: Grant
    Filed: December 1, 1987
    Date of Patent: February 21, 1989
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Shingo Koto
  • Patent number: 4707663
    Abstract: An NMR scanner apparatus uses a permanent magnet comprised of an assembly of magnetic material formed of a substantial number of low energy permanent magnetic elements producing magnetic flux and arranged in at least one row of columns. A frame of magnetically soft material provides a return path for the magnetic flux and provides a surface from which the columns of magnetic elements extend. A flux concentrator plate is disposed adjacent to a surface of the assembly and recessed a sufficient distance from the edge of the assembly to inhibit the loss of magnetic flux. The flux concentrator plate and the frame sandwich the magnetic assembly therebetween. A pole piece consisting of a soft magnetic material is disposed adjacent to a surface of the flux concentrator plate. The pole piece defines a scanning area substantially smaller than the area of the adjacent surface of the flux concentrator plate such that the pole piece exhibits parallel lines of magnetic flux for inducing polarization in living tissue.
    Type: Grant
    Filed: August 15, 1985
    Date of Patent: November 17, 1987
    Assignee: Fonar Corporation
    Inventors: Lawrence A. Minkoff, Gordon T. Danby
  • Patent number: 4706057
    Abstract: A magnet of permanent magnet material for use in a nuclear spin tomograph has a longitudinally extending cavity for receiving a patent, the cavity and the outer contour of the magnet being substantially rectangular. The magnet comprises simple prismatic parts which are assembled unmagnetized. Upon assembly, the magnet is magnetized so that an approximately homogeneous magnetic field prevails in the cavity and the space outside the magnet is approximately free of fields. Magnetically soft plates are disposed on the inside surfaces of two horizontal legs of the magnet.
    Type: Grant
    Filed: May 7, 1986
    Date of Patent: November 10, 1987
    Assignee: Siemens Aktiengesellschaft
    Inventor: August Schwab
  • Patent number: 4701737
    Abstract: A magnetic circuit with a frustum-shaped magnet having a longitudinal bore nd circumscribed by a cladding magnet of varying radial thickness with a non-linear outer exterior surface. The cladding magnet is radially magnetized and the frustum-shaped magnet is axially magnetized, resulting in a constant magnetic potential along the non-linear outer exterior surface of the cladding magnet. A laterally uniform longitudinally increasing magnetic field is created within the bore.
    Type: Grant
    Filed: May 30, 1986
    Date of Patent: October 20, 1987
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Herbert A. Leupold
  • Patent number: 4692732
    Abstract: A magnetic circuit with a remanence varying cylindrical magnet having a b and a remanence varying cladding magnet circumscribing the cylindrical magnet creating a longitudinally increasing axial magnetic field within the bore. The cladding magnet has a radial magnetization transverse to the axial magnetization of the cylindrical magnet resulting in a constant magnetic potential along the outer exterior surface of the magnetic circuit.
    Type: Grant
    Filed: May 30, 1986
    Date of Patent: September 8, 1987
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Herbert A. Leupold, Ernest Potenziani, II, John Clarke
  • Patent number: 4687608
    Abstract: The present invention relates to a composite permanent magnet for magnetic excitation, used in a permanent type rotary machine such as permanent magnet type generators or permanent magnet type motors, which composite magnet comprises a first part and a second part both of which have the same basic composition, the first part having a higher residual magnetic flux density Br than the other, the second part having a higher coercive force .sub.I H.sub.c than the first part, the first and second parts being integrated into one body. The composite permanent magnet has superior characteristics as composite permanent magnet for magnetic excitation.
    Type: Grant
    Filed: June 11, 1985
    Date of Patent: August 18, 1987
    Assignee: Hitachi Metals, Ltd.
    Inventor: Muneyoshi Eino
  • Patent number: 4658228
    Abstract: A magnetic device of permanent magnet materials for the control of linearly xtending annular cross-sectioned magnetic fields formed of two concentrically nesting magnetic tubular elements defining an annular space therebetween, and inner and outer cladding magnets radially disposed around the outer of said tubular elements and interiorly of the inner of said tubular elements, the cladding magnets being thicker at the end extremities and diminishing in thickness towards and to the plane of zero magnetic potential at or near the center line of the device measured along its longitudinal axis.
    Type: Grant
    Filed: May 1, 1986
    Date of Patent: April 14, 1987
    Assignee: The United States of America as represented by the Secreatry of the Army
    Inventor: Herbert A. Leupold
  • Patent number: 4654486
    Abstract: A poor-scatter pot magnet system for magnetic-dynamic loudspeakers or acoustic transducers in which two permanent magnets, of which at least the upper one is a magnet ring. A pole core, an upper, perforated plate and a lower pole plate are built into an iron pot coaxially to one another in such a way that the pole core penetrates the upper magnet ring and the upper, perforated pole plate in a central opening. The upper edge of the iron pot ends in the area of the side of the upper magnet ring below the top thereof.
    Type: Grant
    Filed: October 23, 1984
    Date of Patent: March 31, 1987
    Inventor: Kurt Adolph
  • Patent number: 4654618
    Abstract: A rare earth permanent magnetic apparatus for the containment and control thout any substantial loss of field flux comprising electro-deposited layers of rare earth magnetic material disposed and laid up around a ferrite center core element, the first or inner layer comprising a uniformly thick supply magnet to produce the magnetic field to be controlled, and the second or cladding magnet constituting a layer of diminishing thickness from the outboard ends of the device towards and to the plane of zero magnetic potential at or near the middle of the device.
    Type: Grant
    Filed: May 1, 1986
    Date of Patent: March 31, 1987
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Herbert A. Leupold
  • Patent number: 4647887
    Abstract: A magnetic cladding device having a constant exterior magnetic potential al to a magnetic potential at a point between either end of an active magnet for enhancing the active magnet's field and reducing magnetic field leakage comprising a magnetic cladding circumscribing an active magnet and having a magnetic axis transverse to that of the active magnet.
    Type: Grant
    Filed: December 24, 1984
    Date of Patent: March 3, 1987
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Herbert A. Leupold
  • Patent number: 4644313
    Abstract: A cylindrical permanent magnet apparatus and electromagnet apparatus used with a nuclear magnetic resonance imaging system are disclosed, in which a magnetic path of ferromagnetic material is arranged around a predetermined Z axis, magnetic field source are arranged at the ends of the magnetic path, a cylindrical magnetic flux conductor is interposed between the magnetic field sources, and an object to be inspected is adapted to be inserted in the cylindrical magnetic flux conductor. A cylindrical magnet apparatus comparatively light in weight which has a homogeneous magnetic field and has magnetic shielding effect and is suitable for routine applications is thus provided.
    Type: Grant
    Filed: April 4, 1985
    Date of Patent: February 17, 1987
    Assignee: Hitachi, Ltd.
    Inventor: Goh Miyajima
  • Patent number: 4549155
    Abstract: Two or more magnetically soft pole pieces are symmetrically positioned along a longitudinal axis to provide a magnetic field within a space defined by the pole pieces. Two or more permanent magnets are mounted to an external magnetically-soft cylindrical sleeve which rotates to bring the permanent magnets into closer coupling with the pole pieces and thereby adjustably control the field strength of the magnetic field produced in the space defined by the pole pieces. The permanent magnets are preferably formed of rare earth cobalt (REC) material which has a high remanent magnetic field and a strong coercive force. The pole pieces and the permanent magnets have corresponding cylindrical surfaces which are positionable with respect to each other to vary the coupling therebetween. Auxiliary permanent magnets are provided between the pole pieces to provide additional magnetic flux to the magnetic field without saturating the pole pieces.
    Type: Grant
    Filed: September 20, 1982
    Date of Patent: October 22, 1985
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventor: Klaus Halbach
  • Patent number: 4482034
    Abstract: A switchable permanent magnet eddy current or track brake which has a high density of permanent magnet material, a low internal flux leakage and a higher than heretofore output flux density. The pole shoes of the movable magnets are convex cylindrical segment-shaped and mate with concave cylindrical segment-shaped recesses in the lateral flux return pieces for the fixed magnets.
    Type: Grant
    Filed: October 18, 1982
    Date of Patent: November 13, 1984
    Inventor: Max Baermann
  • Patent number: 4456898
    Abstract: Thermal compensators comprising at least one metallic alloy in amorphous form which are especially useful in stabilizing magnetic devices under conditions of changing ambient operating temperature are provided.
    Type: Grant
    Filed: February 11, 1982
    Date of Patent: June 26, 1984
    Assignee: General Electric Company
    Inventor: Peter G. Frischmann
  • Patent number: 4401960
    Abstract: A magnet assembly used as a magnetism generating source for attaching an article to a magnetic substance or for magnetically retaining a magnetic member. The magnet assembly consists of a cylindrical casing open at least at one end, a core disposed within the casing at a spacing from an inner wall thereof, with one end of the core aligned with the open end face of the casing, and a permanent magnet disposed between the core and the inner peripheral surface of the casing. The permanent magnet has one magnetic pole on an outer surface thereof opposing the inner peripheral surface of the casing, and the other magnetic pole opposite the magnetic pole on an inner surface thereof opposing the outer peripheral surface of the core, so that the open end face of the casing and the end face of the core serve as a magnetic attraction surface.
    Type: Grant
    Filed: December 18, 1979
    Date of Patent: August 30, 1983
    Assignee: Kanetsu Kogyo Kabushiki Kaisha
    Inventors: Mamoru Uchikune, Mutsukazu Tagami, Taketo Shimizu, Kiyoshi Yanagisawa, Katsuto Yokosawa, Kunio Horiuchi, Hiroo Sakaguchi
  • Patent number: 4359706
    Abstract: Pole piece structures for permanent magnets and electromagnets, more particularly for superconducting electromagnets, and pole piece extensions and shields adapted, separately and in combination, to achieve a high concentration of the magnetic flux along the principal magnetic axis of the pole pieces, and preventing magnetic flux leakage and dispersion. The pole pieces are preferably conical or frusto-conical, or in the form of hollow cylinders or conical cylinders or, alternatively, provided with a tapered step ending in a pointed cylinder, a flat cylinder, or a hollow cylinder. The pole piece configurations provide a high concentration of magnetic flux intensity in the magnetic gap between the pole pieces either along the centerline of the pole pieces or in a cylindrical space disposed axially along the centerline of the pole pieces.
    Type: Grant
    Filed: December 18, 1979
    Date of Patent: November 16, 1982
    Inventor: Arnold Flack
  • Patent number: 4256307
    Abstract: A magnetic game comprising a gameboard for use with a magnetizable metal game ball. The gameboard comprises a non-metallic, non-magnetizable rectangular block having a central recess, a thin, non-magnetizable rectangular top plate and a plurality of target areas on a portion of the top plate over the central recess. A thin magnetizable metallic sheet, substantially the same size and shape as the recess, is disposed at the bottom of the recess. A magnetic plate is disposed in the recess over the metallic sheet. A plurality of smaller individual magnetic target elements is disposed on the magnetic plate wherein each element is disposed beneath a target area on the gameboard whereby the game ball is rolled on the top plate and comes to rest over one of the magnetic elements.
    Type: Grant
    Filed: November 29, 1979
    Date of Patent: March 17, 1981
    Inventor: Lesley P. Brooks
  • Patent number: 3992689
    Abstract: A magnet latch assembly for engagement with a flat plate or the like includes a permanent magnet and a surrounding ferromagnetic armature. The parts of the assembly are of an improved construction which facilitates economical assembly procedures and reduces the chances of malfunctioning in use.
    Type: Grant
    Filed: July 28, 1975
    Date of Patent: November 16, 1976
    Assignee: Data Packaging Corporation
    Inventor: Roy Kaplow