From Comminuted Material Patents (Class 29/608)
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Patent number: 5079534Abstract: An apparatus for magnetizing a permanent magnet which includes a frame including first and second relatively movable members arranged to form a core frame which supports first and second conic co-axial poles enclosed by the movable frame members for creating a magnetic flux circuit with an adjustable air gap for enclosing a product to be magnetized. The apparatus is energized by coils wound about the poles and enclosing the air gap. The poles include a bore co-axially aligned with the co-axial axis of the poles and a press ram dimensioned to move within the bore.Type: GrantFiled: September 18, 1990Date of Patent: January 7, 1992Inventors: Erich Steingroever, Dietrich Steingroever
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Patent number: 5069834Abstract: In known electromagnetically actuatable valves having a connection fitting acting as a core and on which a magnet coil is disposed, the magnet coil is surrounded by a solid valve housing of ferromagnetic metal. The manufacture of this valve housing is very labor-intensive and results in undesirably large external dimensions. The valve enables not only simple manufacture but also a reduction in the external dimensions of the valve. In the valve, a plastic sheath surrounding both the connection fitting and the magnet coil is provided, which at least in the region surrounding the magnet coil contains ferromagnetic fillers conducting magnetic field lines. The fillers surround the magnet coil in the circumferential direction. This embodiment of the valve is suitable for electromagneticallly actuatable systems of all kinds.Type: GrantFiled: October 31, 1990Date of Patent: December 3, 1991Assignee: Robert Bosch GmbHInventor: Rudolf Babitzka
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Patent number: 5062197Abstract: A dual-permeability magnetic core structure is provided for use in small, high-frequency inductors and transformers. The dual-permeability core encloses a winding window containing planar windings and comprises high-permeability and low-permeability sections positioned to produce a highly uniform, or uniformly varying, magnetic field on the winding surfaces. The dual-permeability core products low winding losses and a low AC-to-DC resistance ratio. Fabrication of the dual-permeability core involves a method of controlling the permeability of a magnetic material and a methd of combining structures of two different permeability values.Type: GrantFiled: May 7, 1990Date of Patent: November 5, 1991Assignee: General Electric CompanyInventors: Khai D. Ngo, Richard J. Charles
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Patent number: 5041419Abstract: An improved high energy product radially oriented toroidal magnet is made om an iron cylinder toroid by a method including the steps of:(A) sandwiching the iron cylinder toroid between two disc toroids of a superconductive material at a temperature above the transition temperature of the superconductive material at which temperature the superconductive material does not have superconducting properties and therefor cannot affect the magnetic state of the iron toroid,(B) aligning the iron radially with a small applied field so that flux lines go through the toroidal magnet in a radial direction and in response to which the magnetic dipoles of the iron align themselves with those flux lines,(C) cooling the superconductive material to below the transition temperature of the superconductive material thereby trapping magnetic flux in the iron cylinder toroid, and(D) removing the small applied field from the iron cylinder toroid that does not affect the radial magnetization of the iron as the radial magnetization ofType: GrantFiled: April 30, 1990Date of Patent: August 20, 1991Assignee: The United States of America as represented by the Secretary of the ArmyInventor: Herbert A. Leupold
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Patent number: 5026438Abstract: A method is provided for comminuting and mechanically magnetically orienting particles of hot worked rare earth-transition metal-boron alloy to make bonded anistropic magnets. The method involves comminuting a hot-worked body of the alloy to form platelet shaped particles, and applying pressure to the particles in a die in the absence of an external magnetic field.Type: GrantFiled: October 5, 1989Date of Patent: June 25, 1991Assignee: General Motors CorporationInventors: Kevin A. Young, Dennis L. Plackard
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Patent number: 4996764Abstract: In known electromagnetically actuatable valves having a connection fitting acting as a core and on which a magnet coil is disposed, the magnet coil is surrounded by a solid valve housing of ferromagnetic metal. The manufacture of this valve housing is very labor-intensive and results in undesirably large external dimensions. The embodiments of the valve enables not only simple manufacture but also a reduction in the external dimensions of the valve. In the valve, a plastic sheath surrounding both the connection fitting and the magnet coil is provided, which at least in the region surrounding the magnet coil contains ferromagnetic fillers conducting magnetic field lines. The fillers surround the magnet coil in the circumferential direction. This embodiment of the valve is suitable for electromagnetically actuatable systems of all kinds.Type: GrantFiled: April 25, 1990Date of Patent: March 5, 1991Assignee: Robert Bosch GmbHInventor: Rudolf Babitzka
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Patent number: 4990202Abstract: An LC composite component having an integral sintered body formed by cofiring green compacts of an inductor material and a capacitor material in an adhered state.The inductor material and capacitor are both capable of being sintered at a low temperature, so that they may be cofired with substantially no counterdiffusion taking place between them upon cofiring.Type: GrantFiled: January 9, 1989Date of Patent: February 5, 1991Assignee: Murata Manufacturing Co., Ltd.Inventors: Michihiro Murata, Harufumi Mandai, Yasuyuki Naito
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Patent number: 4957668Abstract: A method of concurrently compacting and bonding a plurality of solid particles together including combining particles with a thermobonding agent, placing the particle-agent combination in a die having a desired shape, and applying compaction pressure to the particles while concurrently applying sufficient ultrasonic energy to the particles to densify the particles and thermally activate the thermobonding agent.Type: GrantFiled: December 7, 1988Date of Patent: September 18, 1990Assignee: General Motors CorporationInventors: Dennis L. Plackard, William J. Chafin
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Patent number: 4944270Abstract: An asymmetric excitation type magnetic device is provided with a composite magnetic body composed of a first magnetic layer having a relatively strong coercive force and a second magnetic layer having a relatively weak coercive force which layers are combined so as to have their respective magnetic anisotropy oriented in the same direction. To such a composite magnetic body are applied external positive and negative asymmetric magnetic fields in a specified order thereby to produce variations in magnetic flux due to an escpecially quick magnetization reversal and resultantly to generate steep pulse outputs across a detecting coil.Type: GrantFiled: March 31, 1988Date of Patent: July 31, 1990Inventors: Akira Matsushita, Susumu Abe
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Patent number: 4915891Abstract: A method for producing a noncircular magnet having asymmetric magnetic properties along axes thereof. A particle charge of composition from which the magnet is to be produced is placed in a container, heated and extruded within the container to compact the particle charge to substantially full density. The particle charge may include at least one rare earth element. The particle charge may be extruded through a noncircular extrusion die, specifically a rectangular die.Type: GrantFiled: November 27, 1987Date of Patent: April 10, 1990Assignee: Crucible Materials CorporationInventors: Vijay K. Chandhok, Bao-Min Ma
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Patent number: 4845837Abstract: A rotor assembly for a permanent magnet motor includes a set of laminatings forming a rotor body, each lamination having a first magnet slot therein. A generally rectangular permanent magnet is disposed in the magnet slot, the magnet slot of each lamination being shaped so as to receive the rectangular permanent magnet through all the skewed laminations with a minimum air gap. A method of making an assembly such as a rotor includes the steps of providing an assembly body made of ferromagnetic material defining at least one magnet slot therein. The slot is at least partially filled with a mixture of magnetizable particles in a binder. The mixture is compressed and then cured to bond the magnetizable particles together in the slot and the bonded particles are then magnetized in the slot to form a magnet in situ in the slot without an air gap.Type: GrantFiled: October 6, 1986Date of Patent: July 11, 1989Assignee: Emerson Electric Co.Inventor: Jerry D. Lloyd
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Patent number: 4832891Abstract: A method of making a bonded permanent magnet including the steps of dissolving, in a solvent, an uncured epoxy resin having an incorporated catalyst which is inactive at a temperature of about 120.degree. F. Particles of a rapidly quenched rare earth-iron-boron alloy are added to the epoxy resin solution. The solution with the particles are mixed at a temperature of about 120.degree. F. until the solvent is removed and the magnetic particles are substantially uniformly coated with the resin. The epoxy coated particles are then cold-pressed into a compact to form a magnet and the epoxy compact is then cured by heating.Type: GrantFiled: November 25, 1987Date of Patent: May 23, 1989Assignee: Eastman Kodak CompanyInventor: Allen Kass
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Patent number: 4796354Abstract: A method of manufacturing an angle-of-rotation sensor comprises fabricating a rotating member by providing a shaft coaxially inside a magnetic ring made of ferrite magnetic material or the like, and filling the space between shaft and ring with resin. As the resin is first provided on the outer surface of the magnetic ring, then in the interior, a balance is achieved between tensile stress from within the ring and compressive stress from the outside of the ring, and as a result the ring is not broken or cracked. Thus, with this method it is possible to make the angle-of-rotation sensor small and light.Type: GrantFiled: March 19, 1987Date of Patent: January 10, 1989Assignee: Honda Giken Kogyo Kabushiki KaishaInventors: Toshio Yokoyama, Iwao Shimane, Tsuneo Konno
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Patent number: 4769900Abstract: A chip coil which includes a bobbin, flange portions formed at opposite end portions of the bobbin, a wire wound around a barrel portion of the bobbin, and at least two counter-part blocks of magnetic particle-containing solid resin, disposed around the wound wire. The counter-part blocks of magnetic particle-containing solid resin are adapted to be fixed to each other into one combined unit.Type: GrantFiled: August 5, 1987Date of Patent: September 13, 1988Assignee: Murata Manufacturing Co., Ltd.Inventors: Tetsuya Morinaga, Toshimi Kaneko, Kazuya Nishimura, Yukio Hata
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Patent number: 4713877Abstract: A method of forming a 360.degree. ceramic permanent magnet by utilizing a hot isostatic pressing technique on a ceramic preform paterial cylindrically formed and placed inside a deformable metal housing having an inner diameter that is approximately the same but only slightly larger than the outer diameter of the preform. A solid steel mandrel is provided in the center diameter of the hollow cylindrical preform. Crystal alignment and densification of the ceramic material is achieved by using the hot isostatic pressing technique applied to the outside of the housing, preform and mandrel assembly.Type: GrantFiled: February 5, 1986Date of Patent: December 22, 1987Assignee: Ford Motor CompanyInventors: Edward H. Abbott, Robert H. Erickson, William F. Horn
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Patent number: 4696100Abstract: A method of manufacturing a chip coil, including a coil element which includes a magnetic core, a winding wire, and internal terminal electrodes, a fired mass of magnetic material surrounding and encapsulating the coil element, and external terminal electrodes electrically connected to the internal terminal electrodes. The winding wire is coated with a heat-resistive electrically insulating film and is wound around the magnetic core. The internal terminal electrodes are electrically connected to opposite ends of the winding wire and are exposed to the exterior of the mass at opposite ends of the core where they are electrically connected to the external terminal electrodes.Type: GrantFiled: June 30, 1986Date of Patent: September 29, 1987Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Hiromasa Yamamoto, Sankichi Shida, Tsunehiko Todoroki
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Patent number: 4647890Abstract: An improved solenoid is disclosed. The improvement consists of injection molding one or more components of the magnetic return circuit of the solenoid, particularly the magnetically permeable can, from a polymer having a filler of soft magnetic material at preferably a 20-63% by volume loading level. The injection molded polymer filled solenoid has higher efficiencies than expected based on the decrease in total metal content.Type: GrantFiled: May 15, 1986Date of Patent: March 3, 1987Assignee: Battelle Development CorporationInventors: William E. Riley, Jr., Richard Razgaitis, Raymond E. Mesloh
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Patent number: 4601875Abstract: Permanent magnetic materials of the Fe-B-R type are produced by:preparing an metallic powder having a mean particle size of 0.3-80 microns and a composition of, by atomic percent, 8-30% R (rare earth elements), 2-28% B, and the balance Fe, compacting, sintering at a temperature of 900-1200 degrees C., and aging at a temperature ranging from 350 degrees C. to the temperature for sintering. Co and additional elements M (Ti, Ni, Bi, V, Nb, Ta, Cr, Mo, W, Mn, Al, Sb, Ge, Sn, Zr, Hf) may be present.Type: GrantFiled: September 15, 1983Date of Patent: July 22, 1986Assignee: Sumitomo Special Metals Co., Ltd.Inventors: Hitoshi Yamamoto, Masato Sagawa, Setsuo Fujimura, Yutaka Matsuura
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Patent number: 4597938Abstract: Permanent magnet materials of the Fe-B-R type are produced by:preparing a metallic powder having a mean particle size of 0.3-80 microns and a composition of 8-30 at % R, 2-28 at % B, and the balance Fe,compacting, andsintering, at a temperature of 900-1200 degrees C.Co up to 50 at % may be present. Additional elements M (Ti, Ni, Bi, V, Nb, Ta, Cr, Mo, W, Mn, Al, Sb, Ge, Sn, Zr, Hf) may be present. The process is applicable for anisotropic and isotropic magnet materials.Type: GrantFiled: September 15, 1983Date of Patent: July 1, 1986Assignee: Sumitomo Special Metals Co., Ltd.Inventors: Yutaka Matsuura, Masato Sagawa, Setsuo Fujimura
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Patent number: 4558295Abstract: New ferrite tuning assemblies are disclosed in which a unitary ferrite shaft is covered with a nonmagnetic material to provide a peripheral working surface for coacting with unitary helical thread means in the central opening of a core element to provide axial movement, for air gap adjustment purposes, by cutting and/or deforming at least a portion of the peripheral working surface of the tuning member. Various longitudinal and transverse cross-sectional configurations for the integral male tuning member are made available by the fabrication and assembly methods taught; assembly of inductance-tunable ferrite devices is facilitated by enabling insertion of a male tuning member into the central opening of either core element in an assembly and tuning from either longitudinal end of the aligned central openings.Type: GrantFiled: November 5, 1982Date of Patent: December 10, 1985Assignee: Spang & CompanyInventors: Robert W. Olmsted, Joseph F. Huth, III
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Patent number: 4533407Abstract: Apparatus and method for forming radial orientation rare earth-transition metal magnets in continuous arc rings by hot isostatic pressing. A method includes the steps of compacting rare earth-transition metal powders having a particle size up to 40 microns into radially oriented rings in a mold provided with a radially aligning field, stacking a plurality of compacted radially oriented rings within an annular cavity within a sealed, evacuated cannister to form a cylinder of a predetermined height, subjecting the cannister to temperatures in the range of 900.degree. to 1150.degree. C. under a gas pressure of 15 kpsi to densify the compacts, and cooling the cannister and the compacts to room temperature.Type: GrantFiled: March 30, 1981Date of Patent: August 6, 1985Assignee: The Charles Stark Draper Laboratory, Inc.Inventors: Dilip K. Das, Kaplesh Kumar, Ernest C. Wettstein
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Patent number: 4523170Abstract: New fabricating methods and products are disclosed for manufacture and assembly of tunable-inductance magnetically-soft ferrite core assemblies. Pot core type elements are pressure molded from ferrimagnetic particles having residual reactivity; unitary helical threads are tapped in central openings of compacted core elements while in the green state; subsequent heat treatment converts the green compact to a ceramic. Use of a shrink tap provides compatibility of the unitary threads with the pre-threaded male adjustment members of the prior practice. A new assembly enables use of identical core half sections; provision is made for support at one or both longitudinal ends of the male tuning member.Type: GrantFiled: November 5, 1982Date of Patent: June 11, 1985Assignee: Spang & CompanyInventor: Joseph F. Huth, III
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Patent number: 4520078Abstract: A number of metal cores especially suitable for use in an electrical induction device such as a transformer are disclosed herein along with respective methods of making these cores. In accordance with each of these methods, the appropriate metal material is initially provided and thereafter formed into an unsolidified, preliminary shape. Thereafter, while the material is in its preliminary shape, it is densified, preferably by means of explosion bonding, whereby to improve its permeability and saturation field characteristics. In one embodiment, a metal material is initially provided as a continuous strip. In another embodiment, the metal material is initially provided as a number of plates and still in another, preferred embodiment, amorphous metal particulate material is utilized. In this latter embodiment, the orientation of the particulate material is controlled to further improve the permeability and saturation field characteristics of the ultimately formed core.Type: GrantFiled: June 8, 1981Date of Patent: May 28, 1985Assignee: Electric Power Research Institute, Inc.Inventors: Mario Rabinowitz, E. Robert Perry
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Patent number: 4511872Abstract: New ferrite pot core type products and fabrication methods are disclosed for production and assembly of tunable-inductance magnetically-soft ferrite devices. Unitary helical threads formed within the central opening of a ferrite pot core element provide controlled axial movement of a non-threaded male tuning member, carrying a ferrite rod, to adjust the air gap between spaced center posts of an assembled pair of pot core elements. Thread matching and registry requirements are eliminated by such unitary thread means which present either helical path die means, for cutting threads in a cylindrical nonmagnetic portion of a male tuning member or, circumferentially continuous helical threads, which deform nonmagnetic protrusions uniformly distributed about the periphery of a noncircular cross section nonmagnetic portion of a male tuning member during rotation of a male tuning member within a core element central opening.Type: GrantFiled: November 5, 1982Date of Patent: April 16, 1985Assignee: Spang Industries Inc.Inventors: Robert W. Olmsted, Joseph F. Huth, III
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Patent number: 4490329Abstract: A method for the implosive consolidation into a solid body of a mass of free particles, which mass consists, selectively, entirely of amorphous particles, or a mixture of amorphous and nonamorphous particles. During the consolidation act, pressure and temperature are controlled in a manner which assures that the consolidated amorphous particles in the solid body exhibit substantially the same amorphous characteristics as those displayed by the unconsolidated, free amorphous particles.Type: GrantFiled: September 8, 1983Date of Patent: December 25, 1984Assignee: Oregon Graduate Center for Study and ResearchInventors: Alan W. Hare, Lawrence E. Murr, F. Paul Carlson
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Patent number: 4459248Abstract: A temperature sensitive element comprises fine grain powders which consist of a spin reorientation type ferromagnetic material having a transition temperature range, below which transition temperature range the easy direction of magnetization of the spin reorientation type ferromagnetic material is predetermined in one crystallographic direction thereof and above which transition temperature range the easy direction of magnetization is a predetermined other direction perpendicular to the predetermined one crystallographic direction. The temperature sensitive element is produced by compacting the fine grain powders at a temperature higher than the transition temperature range. According to the present invention, it is possible to use a polycrystalline rare earth cobalt alloy material in the field where low Curie point ferrite has been used or where bimetals have been used for a thermal valve or a temperature controlling device.Type: GrantFiled: March 5, 1982Date of Patent: July 10, 1984Assignee: Fujitsu LimitedInventors: Masato Sagawa, Wataru Yamagishi
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Patent number: 4378247Abstract: A sintered powdered aluminum core for an inductor used in the tuning stages of high frequency equipment is disclosed. Such cores have threads ground on them having sharp thread profiles, as opposed to the flat thread profiles produced by screw machines, and plating the cores produces superior electrical properties.Type: GrantFiled: November 10, 1980Date of Patent: March 29, 1983Assignee: Permacor Altair, Inc.Inventor: Peter A. Tsoutsas
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Patent number: 4325757Abstract: A method is provided for forming rare earth-transition metal (RE-TM) powders directly into radially aligned, thin, curved permanent magnets supported on ferromagnetic backings. Such magnets are particularly suited for use as D.C. motor pole pieces. In the method, a powder cavity is formed between a ferromagnetic backing layer and a composite forming mandrel. The mandrel has a ferromagnetic core slidably retained in a thin magnetic sleeve. The powder in the cavity is pressed in a magnetic field to a density of about 50%. Thereafter, the core of the mandrel is first removed and then the nonmagnetic sleeve. After both mandrel sections are withdrawn, the powders are maintained in the magnet shape for further processing by mechanical interlocking of the particles, and the magnet shape itself is magnetically attracted to the backing layer by the residual magnetism of the powder. The mass may be heated to coalesce the powder and bond it to the backing.Type: GrantFiled: September 4, 1979Date of Patent: April 20, 1982Assignee: General Motors CorporationInventors: William F. Jandeska, Jr., Charles F. Netherton
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Patent number: 4316923Abstract: The process provides practical manufacture of a two-piece, dielectric filled, ferrite toroid assembly while providing optimum electromagnetic characteristics presently not consistently available by manufacturing the toroid in a pressed one-piece configuration. A pair of complementary ferrite blanks of selected shapes are machined to dimension, and the mating surfaces thereof are selectively lapped. The complementary ferrite parts are then permanently assembled about a pre-machined dielectric insert, and the composite toroid is secured together by a selected adhesive selectively disposed therein.Type: GrantFiled: June 26, 1980Date of Patent: February 23, 1982Assignee: Ampex CorporationInventors: Frank R. Monforte, Giltan M. Argentina
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Patent number: 4206866Abstract: Improved apparatus and method for continuously producing high sensitivity magnetochemical particles consisting of joined pairs of pre-oriented magnetic metallic spheres which have been heat treated, magnetically annealed, then plated with color forming metals and overcoated with a chemically resistant coating. These spheres are vibratorially and frictionally seated in surface dimples impressed on the opposed surfaces of a film formed in a mobius loop. The dimples are formed in back-to-back registry by passing the film material through mirror image half-tone screen carrying impressing cylinders. A resin coating applied to the surface of the film loop encases and binds the spheres into mirror image groups; and while the resin coating is still fluid, a directional magnetic field is applied to rotate and orient the encased spheres so that their preferred directions for magnetic field propagation are parallel to the surface of the film loop.Type: GrantFiled: April 21, 1978Date of Patent: June 10, 1980Assignee: Lyne S. TrimbleInventors: Lyne S. Trimble, Florence A. Naylor
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Patent number: 4205430Abstract: When it is not possible to place magnets into their final assembly before magnetizing them, the performance of high energy magnetic materials having a nonlinear demagnetization characteristic at room temperature is improved by heating the magnetic material, magnetizing the heated magnetic material and then placing the resulting heated magnetic into its final assembly and letting it cool to room temperature.Type: GrantFiled: February 27, 1979Date of Patent: June 3, 1980Assignee: The Singer CompanyInventor: Wolfgang Jaffe
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Patent number: 4123297Abstract: In a preferred embodiment, thin curved rare earth-transition metal (RE-TM) compacts with good green strength are made by a stepwise process in the molding cavities of a portable compacting tooling. The powder is partially compacted and magnetically aligned in a first press equipped with magnetizing means. It is then transported in the tooling, which protects the powder from being disturbed during the transportation, to a second press where it is further compacted under much higher loads. The compacts thus formed can be further processed to form thin, curved, densified, permanent rare earth-cobalt magnets particularly suited for use as pole pieces in small, high-torque D.C. motors.Type: GrantFiled: August 1, 1977Date of Patent: October 31, 1978Assignee: General Motors CorporationInventors: William F. Jandeska, Charles F. Netherton, Charles W. Vigor
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Patent number: 4117588Abstract: A method of manufacturing three dimensional integrated circuits from compatible co-fireable materials by extruding batched co-fireable materials to form blocks of specified cross-sections, selecting and stacking cross-section of various widths from different blocks in a specified manner to form the desired circuit and placing the stack in a furnace having a predetermined temperature time profile to properly sinter each of the materials.Type: GrantFiled: January 24, 1977Date of Patent: October 3, 1978Assignee: The United States of America as represented by the Secretary of the NavyInventor: Leopold J. Johnson
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Patent number: 4104787Abstract: In a preferred embodiment thin curved rare earth-cobalt magnets supported on the interior surface of a steel casing are formed by hot isostatic compaction. Rare earth-cobalt powder is magnetically aligned and compacted to at least 65% of the theoretical density. The relatively strong, curved green compacts are positioned on a curved mandrel and placed in a closely fitting steel casing which is evacuated and sealed. The magnets are densified under isostatic gas pressure at elevated temperatures and bonded to the steel. The steel backing serves as an integral motor casing when such magnets are used in D.C. motors.Type: GrantFiled: March 21, 1977Date of Patent: August 8, 1978Assignee: General Motors CorporationInventors: William F. Jandeska, Charles F. Netherton, Charles W. Vigor
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Patent number: 4093906Abstract: A two-cycle engine in such as an outboard motor includes an engine shaft and a flywheel mounted on the shaft and having an inner cylindrical hub portion. A rubber-like magnet strip is adhesively attached about the hub portion with an outer protective shield adhesively bonded to the strip. The strip includes upper and lower magnetic areas which are oppositely and radially magnetized to establish an axially directed field adjacent the outer periphery of the strip. A triggering coil unit includes a C-shaped core with the poles of the core radially aligned with the upper and lower areas of the magnet strip such that the field passes therethrough. The strip is magnetized after assembly by an electromagnetic unit having a semi-circular core with a U-shape cross-section aligned with the strip.Type: GrantFiled: November 28, 1975Date of Patent: June 6, 1978Assignee: Brunswick CorporationInventor: James Richard Draxler
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Patent number: 4051706Abstract: Anisotropic permanent magnets of Mn-Al-C polycrystalline alloy are produced by warm extrusion at a temperature of 530.degree. to 830.degree. C utilizing converging or tapered dies with lubricant interposed between the polycrystalline body and the converging die. With dies of rather small semiangles, alloys with improved magnetic properties with regard to (BH)max, and especially Br are obtained.Type: GrantFiled: July 1, 1975Date of Patent: October 4, 1977Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Yoichi Sakamoto, Nobuyuki Kato, Tadao Ohtani
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Patent number: 4007541Abstract: The process provides practical manufacture of a two-piece, dielectric filled, ferrite toroid assembly while providing optimum electromagnetic characteristics presently not consistently available by manufacturing the toroid in a pressed one-piece configuration. A pair of complementary ferrite blanks of selected shapes are machined to dimension, and the mating surfaces thereof are selectively lapped. The complementary ferrite parts are then permanently assembled about a pre-machined dielectric insert, and the composite toroid is secured together by a selected adhesive selectively disposed therein.Type: GrantFiled: April 14, 1975Date of Patent: February 15, 1977Assignee: Ampex CorporationInventors: Frank R. Monforte, Giltan M. Argentina
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Patent number: RE29476Abstract: The process provides practical manufacture of a two-piece, dielectric filled, ferrite toroid assembly while providing optimum electromagnetic characteristics presently not consistently available by manufacturing the toroid in a pressed one-piece configuration. A pair of complementary ferrite blanks of selected shapes are machined to dimension, and the mating surfaces thereof are selectively lapped. The complementary ferrite parts are then permanently assembled about a pre-machined dielectric insert, and the composite toroid is secured together by a selected adhesive selectively disposed therein.Type: GrantFiled: April 8, 1977Date of Patent: November 22, 1977Assignee: Ampex CorporationInventors: Frank R. Monforte, Giltan M. Argentina