Systems For Magnetizing, Demagnetizing, Or Controlling The Magnetic Field Patents (Class 361/143)
  • Patent number: 5432669
    Abstract: A superconducting magnet apparatus according to the present invention has serially connected superconducting magnets, which are energized and de-energized via disconnectors from a power supply installed on a vehicle of the train, mounted in a pair on both sides of a magnetically levitated train that oppose guiding ground coils of a magnetically levitated railway when the magnetically levitated train is traveling, each superconducting magnet has a plurality of serially connected superconducting coils, persistent current switches are parallel-connected across respective ones of the superconducting coils, and demagnetizers are provided for linking and changing over corresponding persistent current switches mounted in pairs on both sides of the magnetically levitated train.
    Type: Grant
    Filed: October 28, 1993
    Date of Patent: July 11, 1995
    Assignee: Railway Technical Research Institute
    Inventors: Kaoru Nemoto, Hiroki Kamijo, Akihiko Kishikawa, Eiji Suzuki
  • Patent number: 5428332
    Abstract: A process and apparatus for permitting the magnetization of flexible hard magnetic materials in the form of sheets or strips, such as magnetic rubber, wherein opposing arrays formed from alternating magnetic disks and flux conducting elements are use in sets of two with opposing polar moments such as to induce a magnetic flux in the gap between the discs. The width of the magnetic disk and flux conducting elements, respectively, are selected to optimize the magnetic pull strength of the material. At the array ends are flux conducting elements that are about 1/2 (i.e., from about 0.25 to about 0.75, and preferably from about 0.4 to 0.6) of the width of the internal flux conducting elements. A material to be magnetized is passed between the array sets in contrast with both disks and consequently imprinted with magnetic poles. The magnetized properties of the material is enhanced by passing the material through a second set of arrays which are axially offset with respect to the first set of arrays.
    Type: Grant
    Filed: May 26, 1994
    Date of Patent: June 27, 1995
    Assignee: RJF International Corporation
    Inventors: Raymond C. Srail, Richard A. Glover, Thomas R. Szczepanski, Eric M. Weissman, Frederic W. Kunig
  • Patent number: 5327320
    Abstract: An apparatus for suppression of individual ignition events in an ignition system includes a short-circuit switch, connected in parallel to the primary winding of the ignition coil. The short-circuit switch is controlled by a control switch. In order to avoid having to provide a separate power supply to furnish triggering energy to the control switch, this energy is derived from the energy stored in the ignition coil during a closing phase of the ignition switch. This requires fewer components than prior art circuits designed for the same purpose.
    Type: Grant
    Filed: March 25, 1992
    Date of Patent: July 5, 1994
    Assignee: Robert Bosch GmbH
    Inventor: Uwe Fischer
  • Patent number: 5257158
    Abstract: Apparatus for selectively magnetizing and demagnetizing a small tool, such as a screwdriver, by providing an enclosure having a first opening to receive a tool for magnetizing a desired portion of the tool, and a second opening to receive a tool for demagnetizing a selected portion of the tool. The demagnetizing opening is surrounded by a demagnetizing coil that is directly connected through a first switch with a source of alternating current to provide an alternating magnetic field for demagnetizing a tool inserted into the demagnetizing opening. The magnetizing opening is surrounded by a magnetizing coil that is connected through a second switch with the source of alternating current and through a rectifier circuit to provide a continuous magnetic field for magnetizing a tool inserted into the magnetizing opening. Pilot lights are coupled with the respective magnetizing and demagnetizing loops to indicate when the respective loops are energized.
    Type: Grant
    Filed: October 25, 1991
    Date of Patent: October 26, 1993
    Inventor: Mack A. Smith
  • Patent number: 5239442
    Abstract: The device acts by remote action to disperse electric charges or ionic concentrations inside organic or inorganic matter, inside biological matter, or in any other matter in which mobile electric charges exist. The remote action charge transport takes place without direct contact with the matter. The main characteristic resides is in a particular direction or one way motion of the charges from a particular region. The device is useful for charging or discharging regions within bulk matter where electrical contact is either difficult or impossible to establish. The device is also ideal in applying Nordenstrom's method in medicine, where electrical circuits are established between particular regions by inserting electrodes into these regions.
    Type: Grant
    Filed: November 26, 1991
    Date of Patent: August 24, 1993
    Inventors: Jorge Cure, Panagiotis T. Pappas, Harry Eichler
  • Patent number: 5229902
    Abstract: A circuit for reversing a magnetic field in which a bifilar coil is provided with a series of two oppositely-wound windings that are connected together at one end to form a junction. A source of current is connected in series with an inductive resistor, and this series circuit is connected at one end to the junction. At the other end of this series circuit, there is a voltage supply source. Each of the two oppositely-wound windings has its other end connected to a variable switch. The two variable switches have control inputs that are connected to two outputs from a control unit which applies a reference potential to each winding through the variable switch, so that all current from the source of current flows through each winding upon closure of the respective variable switch.
    Type: Grant
    Filed: October 20, 1989
    Date of Patent: July 20, 1993
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventors: Friedhelm Zucker, Christian Buchler
  • Patent number: 5196999
    Abstract: An electrostatic levitation furnace is used for production of microgravity material in space.
    Type: Grant
    Filed: July 10, 1990
    Date of Patent: March 23, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Toshio Abe
  • Patent number: 5171431
    Abstract: An electronic lime controller for controlling lime adjusts for water hardness and the water flow rate in a water system. The controller includes a control for adjusting the frequency of a controller output signal which creates a magnetic field via first and second coils wrapped around a pipe to adjust the controller for changing water flow rates. The controller also includes a control for adjusting the amplitude of the controller output signal based on water hardness rates which generates the magnetic field via the first and second coils.
    Type: Grant
    Filed: May 31, 1991
    Date of Patent: December 15, 1992
    Inventor: Hartmut Schulte
  • Patent number: 5161083
    Abstract: Disclosed is an improved solenoid actuator utilizing an actuator position sensor which in combination with an actuator controller, adjusts the energizing current supplied to the actuator's coil. The adjustment is based upon any difference between an actual position of the actuator and a desired position of the actuator. If there is a difference, the controller changes the energization of the actuator's coil so as to actively move the actuator to the desired position. The improvement can be utilized with existing rotary and linear proportional actuators as well as any other solenoid-type actuator.
    Type: Grant
    Filed: September 9, 1991
    Date of Patent: November 3, 1992
    Assignee: Lucas Ledex Inc.
    Inventors: David B. Mohler, Randy S. Robinson
  • Patent number: 5075814
    Abstract: An external magnetizing method and external magnetizing apparatus for a rotary electric apparatus having internal permanent magnets, which obtains permanent magnetization of metal pieces fixed along the internal circumference of a yoke from the outside of the yoke while the rotor is situated within the yoke. The external magnetizing method includes the steps of creating the permanent magnets by applying a voltage from a capacitor power source to a yoke magnetizing device adjacent the external circumference of the motor yoke, then incrementally rotating the rotor in its normal rotating direction and thereafter reapplying the capacitor power source voltage to the yoke magnetizing means to again magnetize the metal pieces to obtain a more uniform magnetization when using a capacitor power supply .
    Type: Grant
    Filed: February 20, 1990
    Date of Patent: December 24, 1991
    Assignee: Mitsuba Electric Manufacturing Company Ltd.
    Inventors: Toshiharu Kubota, Atsushi Tsuzaki, Yoshiyuki Yokoyama, Saburo Kimura
  • Patent number: 5068039
    Abstract: The device acts by remote action to disperse electric charges or ionic concentrations inside organic or inorganic matter, inside biological matter, or in any other matter in which mobile electric charges exist. The remote action charge transport takes place without direct contact with the matter. The main characteristic resides is in a particular direction or one way motion of the charges from a particular region. The device is useful for charging or discharging regions within bulk matter where electrical contact is either difficult or impossible to establish. The device is also ideal in applying Nordenstrom's method in medicine, where electrical circuits are established between particular regions by inserting electrodes into these regions.
    Type: Grant
    Filed: December 6, 1989
    Date of Patent: November 26, 1991
    Inventors: Jorge Cure, Panagiotis T. Pappas, Harry Eichler
  • Patent number: 5055813
    Abstract: A compact, portable magnetization/demagnetization device comprises a tubular housing internally of which at one end is mounted an electrical coil which surrounds a cavity accessible to screwdrivers and the like. At the opposite end of the housing there is mounted a pair of AC prongs. A manually operated switch on the housing permits the coil to be energized when the prongs are energized to establish a magnetic field in the cavity for the purpose of magnetizing and demagnetizing tools and other objects.
    Type: Grant
    Filed: June 28, 1990
    Date of Patent: October 8, 1991
    Inventor: Terry R. Johnson
  • Patent number: 5032947
    Abstract: A method of improving the magnetic properties of a ferromagnetic materials is disclosed. The method comprises a step of providing a specimen made of Fe, Ni or Co based amorphous alloys in a magnetizing field and a second step of applying an AC current or pulsed current on the specimen to improve its soft magnetic properties. The applied AC current has a frequency of 50 to 50K Hz, a wave form of either sine wave, triangular wave or square wave, and a current density of 10 to 500 A/cm.sup.2. The magnetic properties of the ferromagnetic materials are improved by a coercivity ratio less than 0.5, a magnetic induction ratio greater than 1 and a core loss ratio less than 0.3.
    Type: Grant
    Filed: July 12, 1989
    Date of Patent: July 16, 1991
    Assignees: James C. M. Li, China Steel Corporation
    Inventors: James C. M. Li, Der-Ray Huang
  • Patent number: 4915761
    Abstract: A system for demagnetizing and subsequently selectively magnetizing a small portion of a ferrous member embedded in a green tire carcass in order to facilitate the rotational orientation of the tire carcass when it is transferred to a subsequent processing machine for the application of additional components. A magnetic probe associated with the second processing machine senses the portion of the magnetized area of the bead member and is able to rotationally orient the green tire carcass such that the component applied to the green tire carcass at the second processing machine may be rotationally oriented with respect to the components applied at the first processing machine.
    Type: Grant
    Filed: February 18, 1983
    Date of Patent: April 10, 1990
    Assignee: Bridgestone/Firestone, Inc.
    Inventor: David P. Krause
  • Patent number: 4873605
    Abstract: A device for treatment of ferromagnetic materials comprising means for developing a magnetic field of a selected intensity, duration, and cycle, which field is passed through materials to be processed, such as cutting tools and drill bits that have been sharpened or resharpened and other parts that have internal stresses. The magnetic field through the material provides stress relief of the stresses from welding, forming, heating cooling or sharpening or loading. The treatment increases surface wear resistance, decreases the coefficient of friction on the surfaces that are so treated, and increases the strength and modulus of elasticity. In certain types of materials, an increase in the surface concentration of such alloying metals such as wolfram, molybdenum, and tungsten, as well as oxygen and carbon is achieved. The structure comprises a coil and a controlled source of electrical power that generates a magnetic field for achieving the desired results.
    Type: Grant
    Filed: January 9, 1987
    Date of Patent: October 10, 1989
    Assignee: Innovex, Inc.
    Inventors: Vladimir Drits, Naum Tselesin
  • Patent number: 4795995
    Abstract: A system for producing alternating electromagnetic fields for use in theft detection and surveillance systems, including an arrangement of field-generating inductance coils for disposition on opposite sides of a passage to be monitored by the electromagnetic field produced by such coils. In a preferred such arrangement, upper and lower coils are used on each side of the passage and such coils are mutually distinct from one another and separately energizeable so as to generate separate components of a resulting composite electromagnetic field. The upper and lower coils in each such set are preferably disposed in coplanar alignment with one another but have at least portions of one coil overlapping portions of the other, so as to enhance uniformity in the resulting electromagnetic field. The array of separately-energizeable coils provides for resultant flux vector variation in the magnetic field along three mutually orthogonal axes as a function of coil drive excitation phase variation.
    Type: Grant
    Filed: September 22, 1986
    Date of Patent: January 3, 1989
    Assignee: Progressive Dynamics, Inc.
    Inventors: Larry Eccleston, James C. Cook, II, Earl R. Goodrich, II
  • Patent number: 4761579
    Abstract: A two-dimensional network of alternating (N,S) magnetic poles is generated by a heavy gauge conductor (F) having an alternating current from an excitation source (G) passing therethrough. The conductor follows zigzag go and return paths (T1,T6) without any crossing, juxtaposition, or superposition, thereby simplifying construction. The invention is applicable to handling metal sheets in steel mills.
    Type: Grant
    Filed: May 13, 1987
    Date of Patent: August 2, 1988
    Assignee: Alsthom
    Inventor: Jean Delassus
  • Patent number: 4737753
    Abstract: A multipolar magnetization device comprises at least one electric power source, at least two distinct current pulse generating devices and several portions of electric conductors respectively connected to at least four of said conductor portions for producing a given magnetic field portion. The magnetization device is arranged for creating a series of magnetic field portions of successive alternating polarities for producing in a magnetizable body a corresponding series of magnetized zones.
    Type: Grant
    Filed: October 21, 1985
    Date of Patent: April 12, 1988
    Assignee: Portescap
    Inventor: Claude Oudet
  • Patent number: 4663693
    Abstract: The method for magnetic stabilizing of fluidal layers consists in placing fluidal layers of ferromagnetic particles in a magnetic field that is axially gradient and oriented parallel to the direction of fluidizing. In order to achieve dynamic uniformity of the layer the magnetic field can be oriented colinearly to the direction of fluidizing. For manifold increase in the fluidizing flow the magnetic moment of the particles can be oriented against the direction of the fluidizing flow.This method can be used in heterogenic and physical processes with fluidal layers of ferromagnetic particles, f.e. catalytic processes, filtration etc.
    Type: Grant
    Filed: January 29, 1986
    Date of Patent: May 5, 1987
    Assignee: Vish Chimiko-Technologicheski Institute
    Inventors: Ivaylo A. Zrantchev, Todorka F. Popova
  • Patent number: 4648004
    Abstract: Disclosed are a method of detecting a magnetic preorientation in mechanical parts, such as motor rotors, and a device, utilizing this method, for the magnetization of tubular parts. The device includes a magnetization winding to accommodate the tubular part and an associated magnetizing apparatus. According to the invention, the part (100) is first magnetized near the surface by means of a recording head (300) in such a manner that discrete bar magnets (121 to 132) are formed on the surface between the preoriented zones in the circumferential direction, their lines of flux running between their poles in the preferred direction of the preoriented material, There originate in the preoriented pole zones outside stray fields of twice the number of poles used to position the part (100) during magnetization.
    Type: Grant
    Filed: October 10, 1985
    Date of Patent: March 3, 1987
    Assignee: Siemens Aktiengesellschaft
    Inventors: Martin Richter, Reinhold Piesch
  • Patent number: 4614929
    Abstract: A method for the manufacture of an annular magnet, which comprises depositing, on the opposite sides of an annular material of magnetic substance, magnetizing members regularly spaced circumferentially in conformity with the shape of said annular material and opposed perpendicularly to each other across said annular material and forming magnetic fluxes through paired magnetizing members in alternately opposite directions thereby magnetizing said interposed annular material.
    Type: Grant
    Filed: March 25, 1985
    Date of Patent: September 30, 1986
    Assignee: Nihon Radiator Co., Ltd.
    Inventors: Takaaki Tsukuda, Toyohiko Hata, Akira Fujisaki
  • Patent number: 4551781
    Abstract: A control circuit for a magnetic probe. A power supply connects the available power to the direct voltages required to control electronic circuitry, and a voltage required for the magnetic probe. A clock establishes a time base for the entire device. A current alternator changes the direction of current flow through the magnet to change the polarity, and a pulse rate control sets the frequency with which the polarity is changed. The current alternator is variable to allow one polarity to remain for a longer time than the other, and to vary the timing for each. The frequency of the pulsing is counted, and the particular frequency is displayed in readable form.
    Type: Grant
    Filed: August 3, 1983
    Date of Patent: November 5, 1985
    Assignees: Chris G. Nicholson, J. Gid Parrish, Ivan H. Brown, Reuben H. Gordon
    Inventor: Rocky S. Bykerk
  • Patent number: 4537850
    Abstract: A method and apparatus for rejuvenating magnetic toner used in certain electrostatic copying machines. The used toner is placed in a container which is inserted in an air coil which is energized to produce a magnetic field which remagnetizes the toner. The coil is provided by mounting a hollow non-magnetic tube in a case and winding this tube with wire. A timing circuit energized by a momentary switch determines the length of time a magnetic field is applied to the toner being recycled.
    Type: Grant
    Filed: August 30, 1983
    Date of Patent: August 27, 1985
    Inventor: Wilfred Smeiman
  • Patent number: 4471403
    Abstract: A dual-function circuit is provided which may be used to both magnetically bias and alternately, quickly degauss a magnetic device. The circuit may be magnetically coupled or directly connected electrically to a magnetic device, such as a magnetostrictive transducer, to magnetically bias the device by applying a d.c. current and alternately apply a selectively damped a.c. current to the device to degauss the device. The circuit is of particular value in many systems which use magnetostrictive transducers for ultrasonic transmission in different propagation modes over very short time periods.
    Type: Grant
    Filed: October 4, 1983
    Date of Patent: September 11, 1984
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: William B. Dress, Jr., David R. McNeilly
  • Patent number: 4409581
    Abstract: The process for magnetizing two opposite surfaces of a magnetizable body according to predetermined vectors includes the engagement of two magnetizing heads with each surface and rotation of the two heads relative to each other through a compensating angle corresponding to the angular deviation of actual magnetization from the desired position of magnetization vectors. Apparatus for performing such magnetization involves two juxtaposed magnetizing heads which are rotatable relative to one another.
    Type: Grant
    Filed: July 3, 1980
    Date of Patent: October 11, 1983
    Assignee: Internationale Patente Verwertungsgesellschaft m.b.H.
    Inventor: Franz Reumann
  • Patent number: 4395746
    Abstract: A method and device for magnetically transporting finely divided magnetic particles accumulated or deposited at a space. First a DC magnetic field is exerted to the finely divided magnetic particles so as to magnetize and bring them into an easy-to-be-handled state and then revolving alternating fields are exerted to the magnetized, finely divided magnetic particles, thereby magnetically transporting them.
    Type: Grant
    Filed: April 24, 1980
    Date of Patent: July 26, 1983
    Assignees: Ishikawajima-Harima Jukogyo Kabushiki Kaisha, Tohoku Kinzoku Kogyo Kabushiki Kaisha
    Inventors: Hiroto Tanaka, Yasumasa Kohno, Hideyuki Tanaka, Kotaro Sasaki
  • Patent number: 4381492
    Abstract: Apparatus for magnetizing permanent magnet bodies to provide them with narrow magnetic poles of alternating polarity consists of arranging an array of pairs of magnetizing conductors in such a manner that when each of the two conductors of each pair are connected in series each of the pairs of conductors can be connected in parallel directly to the two common magnetizing current supply leads.
    Type: Grant
    Filed: August 18, 1981
    Date of Patent: April 26, 1983
    Inventors: Erich Steingroever, Dietrich Steingroever
  • Patent number: 4373174
    Abstract: A method for the protective magnetization of vessels by using magnetic loops (11).The field strength of the magnetic field surrounding the vessel is detected by means of a Hall generator (12) and the current through the magnetic loop (11) is controlled in dependence on the field strength thus detected.
    Type: Grant
    Filed: November 25, 1980
    Date of Patent: February 8, 1983
    Inventor: Nils B. Akesson
  • Patent number: 4287512
    Abstract: Matching components of a magnetic locking assembly are magnetically attracted into mating relationship until a predetermined magnetic flux is established in one of the components. Such established predetermined flux is monitored to detect locking power diminutions between the locking assembly components. External magnetic fields applied to the locking assembly in an attempt to counterfeit the mentioned predetermined magnetic flux may be detected and indicated for security reasons.
    Type: Grant
    Filed: March 31, 1980
    Date of Patent: September 1, 1981
    Assignee: Dynametric, Inc.
    Inventor: C. Marlon Combs
  • Patent number: 4186364
    Abstract: A method of magnetizing an erasing head for small type tape recorders is disclosed. An erasing head having its opposite ends formed in at least one convex surface is disposed in a space formed between at least two opposed electromagnetic poles. That surface of the electromagnetic pole which is opposed to the convex surface of the erasing head is made concave which corresponds in curvature to the convex surface of the erasing head such that a tangential direction of a tape travelling movement is perpendicular to a direction of a magnetic flux of the erasing head. In addition, a center axis of the erasing head is mechanically aligned with a center axis common to both the opposite electromagnetic poles by means of a jig such that a widthwise direction of a tape is perpendicular to the direction of magnetic flux of the erasing head.
    Type: Grant
    Filed: June 8, 1978
    Date of Patent: January 29, 1980
    Assignee: Olympus Optical Limited
    Inventor: Naohiro Hanaoka
  • Patent number: 4169998
    Abstract: Disclosed is an iron core assembly for magnetizing columnar permanent magnet, particularly columnar ceramic permanent magnets adapted for use in magnetic-brush type electrostatic developing apparatus. The invention is to clarify the magnetic pattern most effective for the development, as well as a construction for presenting such a pattern, and is aiming to provide a magnetizing iron core assembly having an improved construction of magnetic poles and magnetizing coil windings.
    Type: Grant
    Filed: October 3, 1977
    Date of Patent: October 2, 1979
    Assignee: Hitachi Metals, Ltd.
    Inventors: Hideki Harada, Keitaro Yamashita, Katsunobu Yamamoto
  • Patent number: 4168481
    Abstract: A core assembly for magnetizing a columnar permanent magnet, especially a columnar ceramic permanent magnet, adapted for use in an electrostatic developing apparatus of magnetic-brush developing type. The magnetizing iron core assembly has a specific arrangement of magnetic poles and magnetizing coil windings for providing a specific pattern of magnetic flux distribution which would provide the most efficient development.
    Type: Grant
    Filed: October 5, 1977
    Date of Patent: September 18, 1979
    Assignee: Hitachi Metals, Ltd.
    Inventors: Hideki Harada, Keitaro Yamashita, Katsunobu Yamamoto
  • Patent number: 4167718
    Abstract: Disclosed is an improved dies set for magnetizing a cylindrical or columnar magnet adapted for use in an electrostatic developing apparatus of magnetic-brush developing type. The dies set is intended for imparting axially extending and circumferentially alternating magnetic poles to the periphery of the cylindrical columnar permanent magnet. The magnetizing dies set of the invention has a specific pattern of magnetic pole arrangement for rendering the distribution of magnetic attracting force, which is to be permanently applied to the peripheral surface of the columnar magnet in the magnetic developer, so that the attracting force becomes as uniform as possible, over the entire periphery of a shell surrounding the permanent magnet.
    Type: Grant
    Filed: October 3, 1977
    Date of Patent: September 11, 1979
    Assignee: Hitachi Metals, Ltd.
    Inventors: Hideki Harada, Keitaro Yamashita, Katsunobu Yamamoto
  • Patent number: 4166263
    Abstract: Disclosed is a magnetic core assembly for magnetizing columnar permanent magnet, particularly columnar ceramic permanent magnet adapted for use in magnetic-brush type electrostatic developing apparatus. The invention is to clarify the magnetic pattern most effective for the development, as well as a construction for presenting such a pattern, and is aiming to provide a magnetizing iron core assembly having an improved construction of magnetic poles and magnetizing coil windings.
    Type: Grant
    Filed: October 3, 1977
    Date of Patent: August 28, 1979
    Assignee: Hitachi Metals, Ltd.
    Inventors: Hideki Harada, Keitaro Yamashita, Katsunobu Yamamoto
  • Patent number: 4165528
    Abstract: A fault indicator for alternating current distribution systems includes a pair of spaced pole pieces for receiving therebetween at one end the conductor and at the other end a pivoted permanent magnet carrying a target that is biased to a fault indicating position by a stationary permanent magnet. The pole pieces are demagnetized on flow of fault current in the conductor. They are remagnetized by a winding which is energized by discharge of a capacitor that is charged through a rectifier from an oscillator circuit. The winding is carried by a receptacle into which the other ends of the pole pieces are inserted and a circuit is completed thereby to charge the capacitor. The receptacle is carried at one end of a tubular housing the other end of which has an eye to receive a claw of a live line tool for applying the fault indicator to and removing it from the conductor.
    Type: Grant
    Filed: February 13, 1978
    Date of Patent: August 21, 1979
    Inventor: Edmund O. Schweitzer, Jr.
  • Patent number: 4160283
    Abstract: A magnetizable iron core is surrounded by a magnetizing solenoid coil which can be energized by 60 hertz regular house power. An article of magnetizable material to be magnetized is placed adjacent the core and the solenoid coil is energized. A normally closed dwell switch in series with the solenoid coil is activated by the magnetization of the iron core to move to an open condition to interrupt flow to the solenoid after first permitting current to flow in said solenoid coil momentarily. Upon sucn interruption of current flow to the solenoid, the article is magnetized. To demagnetize an article, it is put in contact with the iron core, and means is provided to override the dwell switch. The solenoid coil is continuously energized. The article to be demagnetized is then moved away from the iron core. The resulting decreasing alternating current field completely demagnetizes the article.
    Type: Grant
    Filed: April 26, 1978
    Date of Patent: July 3, 1979
    Assignee: Howard A. Spoklie
    Inventor: Ralph W. Adams
  • Patent number: 4146956
    Abstract: Alternate S- and N-poles are disposed on a multipolar erasing head in the direction of a relative movement of the multipolar erasing head to a magnetic recording medium. The multipolar erasing head includes at least one region where the distances between adjacent magnetic poles of the same polarity are successively shortened in the direction for successively erasing the information recorded on the recording medium. A method and apparatus for manufacturing such an erasing head are also disclosed.
    Type: Grant
    Filed: September 7, 1977
    Date of Patent: April 3, 1979
    Assignee: Tokyo Shibaura Electric Co., Ltd.
    Inventor: Tatsuo Fujiwara
  • Patent number: 4148091
    Abstract: An electromagnetic force (EMF) machine with a universal portable power supply is disclosed. The universal portable power supply energizes either a multiple turn flux concentrator or a single turn flux concentrator. The flux concentrators produce magnetic fields that create an outward tension force adapted to perform non-destructive bond tests (tension proof loading) and/or dent removal operations on panels or the like. The power supply includes a slow current pulse subsystem; a fast current pulse subsystem; slow and fast crowbars; and, a firing control. The firing control controls the production of pulses by the slow and a fast current pulse subsystems, and, the operation of the slow and fast crowbars. The slow pulse subsystem, via the flux concentrator, slowly creates a magnetic field that penetrates the panel; the fast pulse subsystem, via the flux concentrator, rapidly decreases the magnetic field, whereby a negative field gradient is produced across the panel.
    Type: Grant
    Filed: December 27, 1977
    Date of Patent: April 3, 1979
    Assignee: The Boeing Company
    Inventors: Karl A. Hansen, Iver G. Hendrickson
  • Patent number: 4116031
    Abstract: A flux concentrator has a pair of primary coils wrapped around a thin walled cylindrical portion of a secondary coil. The secondary coil has a conductive head at an end and the coil is slotted to generate a rapid high intensity axially acting flux at the head in response to a flow of current through the primary coils. A pulling force is generated as a result of a slow rise high amplitude current flow through one of the coils followed by a rapid rise reversed polarity current flow through the second primary coil.
    Type: Grant
    Filed: December 20, 1976
    Date of Patent: September 26, 1978
    Assignee: The Boeing Company
    Inventors: Karl A. Hansen, I. Glen Hendrickson