Systems For Magnetizing, Demagnetizing, Or Controlling The Magnetic Field Patents (Class 361/143)
-
Patent number: 5654864Abstract: A control method permits the operation of multiple superconducting magnetic coils so as to move a magnetic object to precisely specified locations within the body under command of a physician-operator observing the motion with live fluoroscopic imaging fused with more detailed preoperative imaging of some other kind. A computer contains the preoperative images and the fluoroscopic images, as well as the means to effect changes in the coil currents so as to accomplish the desired magnetic object motion and positioning. The control method operates the coils in pairs on opposite sides of the body in a manner to minimize the necessary current changes, thus avoiding the quenching of the superconducting coils. Combinations of these pairs can execute motion of the magnetic object in any direction in an impulsive manner and with high precision. The method should function well and provide advantages with coils which are not superconducting as well.Type: GrantFiled: July 25, 1994Date of Patent: August 5, 1997Assignees: University of Virginia Patent Foundation, Stereotaxis, Inc.Inventors: Rogers C. Ritter, Michael A. Lawson, Robert G. McNeil
-
Patent number: 5586064Abstract: The present invention provides a magnetic compensation system and a method of utilizing a magnetic compensation system to neutralize magnetic fields in an environment of a magnetically sensitive instrument. A magnetometer is used to sense magnetic field components in the environment and convert them into a signal. The signal is filtered to remove frequency components associated with the resonant frequency of the compensation system. The filtered signal is amplified by a signal amplifier and amplified by a power amplifier to generate current to drive a semi-Helmholtz coil disposed in the environment of the instrument. Magnetic fields are produced by the semi-Helmholtz coil which neutralize the sensed magnetic fields. The filter may be implemented using either a low-pass filter or a notch filter with notch frequencies set to the resonant frequency and harmonics thereof.Type: GrantFiled: November 3, 1994Date of Patent: December 17, 1996Assignee: The Trustees of the University of PennsylvaniaInventor: Daniel Grupp
-
Patent number: 5557248Abstract: An apparatus for making permanent magnet material magnetizes a body of material including a primary winding which has portions wound on a first core carrying current in a first direction creating a first field of flux and a secondary winding having portions wound on a second core wherein the secondary winding carries current in a second opposing direction to create a second field of flux. Since the currents are flowing in opposing directions, the secondary field of flux is directed to oppose the first field of flux. The result of this is that the magnetizer is capable of controlling the width of the pole to pole transition region for matching the stator geometry and thereby nearly eliminating cogging torque and reducing ripple torque.Type: GrantFiled: February 24, 1994Date of Patent: September 17, 1996Assignee: Synektron CorporationInventor: Vaclav Prochazka
-
Patent number: 5515233Abstract: An electric control circuit of an electromagnetic clutch includes a relay-controlled, two-position switch which operates, in response to a power source being disconnected from the switch relay and the clutch, to establish a path to ground through which the induced voltage of the clutch may be dissipated to thereby speed up the disengagement of the clutch once power thereto is discontinued. The control circuit may be that employed in a self-propelled forage harvester equipped with a metal detector, the latter including a normally closed relay switch which opens in response to metal being sensed to thereby de-energize the clutch and two-position switch relay.Type: GrantFiled: September 13, 1994Date of Patent: May 7, 1996Assignee: Deere & CompanyInventor: Manfred Hofmann
-
Patent number: 5495230Abstract: A marker for use in a magnetomechanical electronic article surveillance (EAS) system is made by mounting a magnetostrictive element in a housing adjacent to a biasing element that is magnetized to a degree of magnetization that is less than saturation. The resonant frequency of the marker is detected. If the detected resonant frequency does not match a predetermined operating frequency of the EAS system, the degree of magnetization of the biasing element is adjusted so as to tune the resonant frequency of the marker to the predetermined operating frequency.Type: GrantFiled: August 10, 1994Date of Patent: February 27, 1996Assignee: Sensormatic Electronics CorporationInventor: Ming-Ren Lian
-
Patent number: 5467243Abstract: Alternating current provided at an angular frequency (.omega.) for powering an electromagnet force actuator having a leakage inductance (L.sub.1) whereby the alternating current is controlled by a voltage reference and a feedback signal indicative of the controlled current and amplified at a gain factor (K.sub.1) having a magnitude greater than or equal to the leakage inductance (L.sub.1) times the angular frequency (.omega.), whereby the electromagnet has a flat or positive spring rate.Type: GrantFiled: September 29, 1993Date of Patent: November 14, 1995Assignee: Otis Elevator CompanyInventor: Clement A. Skalski
-
Patent number: 5432669Abstract: 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: GrantFiled: October 28, 1993Date of Patent: July 11, 1995Assignee: Railway Technical Research InstituteInventors: Kaoru Nemoto, Hiroki Kamijo, Akihiko Kishikawa, Eiji Suzuki
-
Patent number: 5428332Abstract: 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: GrantFiled: May 26, 1994Date of Patent: June 27, 1995Assignee: RJF International CorporationInventors: Raymond C. Srail, Richard A. Glover, Thomas R. Szczepanski, Eric M. Weissman, Frederic W. Kunig
-
Patent number: 5327320Abstract: 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: GrantFiled: March 25, 1992Date of Patent: July 5, 1994Assignee: Robert Bosch GmbHInventor: Uwe Fischer
-
Patent number: 5257158Abstract: 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: GrantFiled: October 25, 1991Date of Patent: October 26, 1993Inventor: Mack A. Smith
-
Patent number: 5239442Abstract: 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: GrantFiled: November 26, 1991Date of Patent: August 24, 1993Inventors: Jorge Cure, Panagiotis T. Pappas, Harry Eichler
-
Patent number: 5229902Abstract: 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: GrantFiled: October 20, 1989Date of Patent: July 20, 1993Assignee: Deutsche Thomson-Brandt GmbHInventors: Friedhelm Zucker, Christian Buchler
-
Patent number: 5196999Abstract: An electrostatic levitation furnace is used for production of microgravity material in space.Type: GrantFiled: July 10, 1990Date of Patent: March 23, 1993Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Toshio Abe
-
Patent number: 5171431Abstract: 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: GrantFiled: May 31, 1991Date of Patent: December 15, 1992Inventor: Hartmut Schulte
-
Patent number: 5161083Abstract: 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: GrantFiled: September 9, 1991Date of Patent: November 3, 1992Assignee: Lucas Ledex Inc.Inventors: David B. Mohler, Randy S. Robinson
-
Patent number: 5075814Abstract: 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: GrantFiled: February 20, 1990Date of Patent: December 24, 1991Assignee: Mitsuba Electric Manufacturing Company Ltd.Inventors: Toshiharu Kubota, Atsushi Tsuzaki, Yoshiyuki Yokoyama, Saburo Kimura
-
Patent number: 5068039Abstract: 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: GrantFiled: December 6, 1989Date of Patent: November 26, 1991Inventors: Jorge Cure, Panagiotis T. Pappas, Harry Eichler
-
Patent number: 5055813Abstract: 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: GrantFiled: June 28, 1990Date of Patent: October 8, 1991Inventor: Terry R. Johnson
-
Patent number: 5032947Abstract: 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: GrantFiled: July 12, 1989Date of Patent: July 16, 1991Assignees: James C. M. Li, China Steel CorporationInventors: James C. M. Li, Der-Ray Huang
-
Patent number: 4915761Abstract: 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: GrantFiled: February 18, 1983Date of Patent: April 10, 1990Assignee: Bridgestone/Firestone, Inc.Inventor: David P. Krause
-
Patent number: 4873605Abstract: 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: GrantFiled: January 9, 1987Date of Patent: October 10, 1989Assignee: Innovex, Inc.Inventors: Vladimir Drits, Naum Tselesin
-
Patent number: 4795995Abstract: 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: GrantFiled: September 22, 1986Date of Patent: January 3, 1989Assignee: Progressive Dynamics, Inc.Inventors: Larry Eccleston, James C. Cook, II, Earl R. Goodrich, II
-
Patent number: 4761579Abstract: 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: GrantFiled: May 13, 1987Date of Patent: August 2, 1988Assignee: AlsthomInventor: Jean Delassus
-
Patent number: 4737753Abstract: 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: GrantFiled: October 21, 1985Date of Patent: April 12, 1988Assignee: PortescapInventor: Claude Oudet
-
Patent number: 4663693Abstract: 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: GrantFiled: January 29, 1986Date of Patent: May 5, 1987Assignee: Vish Chimiko-Technologicheski InstituteInventors: Ivaylo A. Zrantchev, Todorka F. Popova
-
Patent number: 4648004Abstract: 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: GrantFiled: October 10, 1985Date of Patent: March 3, 1987Assignee: Siemens AktiengesellschaftInventors: Martin Richter, Reinhold Piesch
-
Patent number: 4614929Abstract: 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: GrantFiled: March 25, 1985Date of Patent: September 30, 1986Assignee: Nihon Radiator Co., Ltd.Inventors: Takaaki Tsukuda, Toyohiko Hata, Akira Fujisaki
-
Patent number: 4551781Abstract: 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: GrantFiled: August 3, 1983Date of Patent: November 5, 1985Assignees: Chris G. Nicholson, J. Gid Parrish, Ivan H. Brown, Reuben H. GordonInventor: Rocky S. Bykerk
-
Patent number: 4537850Abstract: 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: GrantFiled: August 30, 1983Date of Patent: August 27, 1985Inventor: Wilfred Smeiman
-
Patent number: 4471403Abstract: 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: GrantFiled: October 4, 1983Date of Patent: September 11, 1984Assignee: The United States of America as represented by the United States Department of EnergyInventors: William B. Dress, Jr., David R. McNeilly
-
Patent number: 4409581Abstract: 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: GrantFiled: July 3, 1980Date of Patent: October 11, 1983Assignee: Internationale Patente Verwertungsgesellschaft m.b.H.Inventor: Franz Reumann
-
Patent number: 4395746Abstract: 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: GrantFiled: April 24, 1980Date of Patent: July 26, 1983Assignees: Ishikawajima-Harima Jukogyo Kabushiki Kaisha, Tohoku Kinzoku Kogyo Kabushiki KaishaInventors: Hiroto Tanaka, Yasumasa Kohno, Hideyuki Tanaka, Kotaro Sasaki
-
Patent number: 4381492Abstract: 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: GrantFiled: August 18, 1981Date of Patent: April 26, 1983Inventors: Erich Steingroever, Dietrich Steingroever
-
Patent number: 4373174Abstract: 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: GrantFiled: November 25, 1980Date of Patent: February 8, 1983Inventor: Nils B. Akesson
-
Patent number: 4287512Abstract: 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: GrantFiled: March 31, 1980Date of Patent: September 1, 1981Assignee: Dynametric, Inc.Inventor: C. Marlon Combs
-
Patent number: 4186364Abstract: 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: GrantFiled: June 8, 1978Date of Patent: January 29, 1980Assignee: Olympus Optical LimitedInventor: Naohiro Hanaoka
-
Patent number: 4169998Abstract: 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: GrantFiled: October 3, 1977Date of Patent: October 2, 1979Assignee: Hitachi Metals, Ltd.Inventors: Hideki Harada, Keitaro Yamashita, Katsunobu Yamamoto
-
Patent number: 4168481Abstract: 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: GrantFiled: October 5, 1977Date of Patent: September 18, 1979Assignee: Hitachi Metals, Ltd.Inventors: Hideki Harada, Keitaro Yamashita, Katsunobu Yamamoto
-
Patent number: 4167718Abstract: 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: GrantFiled: October 3, 1977Date of Patent: September 11, 1979Assignee: Hitachi Metals, Ltd.Inventors: Hideki Harada, Keitaro Yamashita, Katsunobu Yamamoto
-
Patent number: 4166263Abstract: 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: GrantFiled: October 3, 1977Date of Patent: August 28, 1979Assignee: Hitachi Metals, Ltd.Inventors: Hideki Harada, Keitaro Yamashita, Katsunobu Yamamoto
-
Patent number: 4165528Abstract: 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: GrantFiled: February 13, 1978Date of Patent: August 21, 1979Inventor: Edmund O. Schweitzer, Jr.
-
Patent number: 4160283Abstract: 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: GrantFiled: April 26, 1978Date of Patent: July 3, 1979Assignee: Howard A. SpoklieInventor: Ralph W. Adams
-
Patent number: 4146956Abstract: 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: GrantFiled: September 7, 1977Date of Patent: April 3, 1979Assignee: Tokyo Shibaura Electric Co., Ltd.Inventor: Tatsuo Fujiwara
-
Patent number: 4148091Abstract: 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: GrantFiled: December 27, 1977Date of Patent: April 3, 1979Assignee: The Boeing CompanyInventors: Karl A. Hansen, Iver G. Hendrickson
-
Patent number: 4116031Abstract: 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: GrantFiled: December 20, 1976Date of Patent: September 26, 1978Assignee: The Boeing CompanyInventors: Karl A. Hansen, I. Glen Hendrickson