Abstract: Magnetostrictive wire having a low surface-to-volume ratio established by a onstant non-planar cross-section, is helically deformed into contact with a shaft under a stress maintaining the wire in fixed relation to the shaft surface. Magnetic anisotropy is imparted to the wire by twist thereof about its cross-sectional axis while the wire is being helically deformed into contact with the shaft surface to form a torque sensor through which accurate torque detection is achieved.

Abstract: A magnetic marker serving to locate, trace, and identify an elongated hidden object, such as a buried utility pipe, duct, conduit, or fiber optic cable, is manufactured by applying magnetic material to a substrate that is elongated and by forming from the material a helical or twisted permanent magnet pattern extending along the length of the substrate. The magnetic material, which may be coextensive with the substrate or applied to a portion only of the substrate, may be formed as a strip coextruded with the substrate and magnetized in the direction of the width of the strip. Alternatively, magnetic material may be mixed with the material from which the substrate is extruded or may be coated on the substrate. A strip may also be preformed and applied to an elongated object as the object is buried, or the strip may form a separate warning tape that is buried with the object and that is provided with a desired magnetic signature by twisting the strip lengthwise as it is advanced for burial.

Abstract: In a brush motor comprising a stator assembly constituted by a permanent magnet assembly and a cylindrical yoke, a stator provided with coils diametrically opposing to each other and rotatably disposed within the stator assembly, and a brush, the permanent magnet assembly is constituted by two arc segment magnets each having magnetic anisotropy in a radial direction and an arc angle .theta. of 170.degree.-180.degree., so that the permanent magnet assembly has a magnetic flux density distribution having a smooth wave form substantially free from localized deformations in a circumferential direction approximately on an inner surface thereof. Such an arc segment magnet is manufactured by a wet molding method and sintering.

Abstract: A small, high-frequency, high-efficiency inductor includes a segmented toroidal core with a winding wound thereon. The toroidal core has either a solid core structure, a laminated core structure, or a strip-wound core structure that is cut into segments. The segmented toroidal core is made of a relatively high-permeability magnetic material and has a plurality of narrow gaps having a width less than approximately 2% of an average linear dimension across the face of each segment. Nonconductive, nonmagnetic spacers are inserted and bonded in the gaps. The inductor winding preferably comprises litz wire in order to further reduce losses.

Abstract: Disclosed is a method of manufacturing an acceleration sensor including: a cylindrical body composed of a conductive material; a magnetized inertial body so charged in an interior of the cylindrical body as to be movable in the longitudinal direction of the cylindrical body; a conductive body provided on an end surface of at least one end of the magnetized inertial body in the longitudinal direction of the cylindrical body; a pair of electrodes disposed at one end in the longitudinal direction of the cylindrical body and made conductive through the conductive body when contacting the conductive body of the magnetized inertial body; and an attracting body composed of a magnetic material, disposed at the other end in the longitudinal direction of the cylindrical body and magnetically mutually attracting the magnetized inertial body, the method comprising the steps of: assembling the acceleration sensor by incorporating the inertial body before becoming the magnetized inertial body by magnetization; and magnetiz

Abstract: A method of making a rotor for an electromagnetic clutch. The rotor comprises an inner annular portion, an annular clutch portion extending outwardly from an end of the inner annular portion and having a series of arcuate slots extending therethrough and an outer annular portion extending from an outer end of the annular clutch portion. The clutch portion has a coupling surface finished for engaging a cooperating coupling surface of an armature having a series of arcuate slots therein cooperable with the arcuate slots of the clutch portion so as to establish a magnetic flux path which passes back and forth between the rotor clutch portion and the armature a plurality of times.

Abstract: One face of a coupling disc (i.e., the armature or rotor) of an electromagnetic coupling such as a clutch or brake is formed with a plurality of radially spaced and circumferentially extending grooves. The other face of the disc is formed with a plurality of radially spaced rows of circumferentially extending slots which communicate with the grooves so as to form air gaps completely through the disc. In the preferred embodiment, each groove is circumferentially continuous while each row of slots is defined by circumferentially spaced slots which are separated by short bridges. By virtue of forming the grooves in the disc, only a small thickness of material need be removed from the disc in order to form the slots.

Abstract: Disclosed is a retaining band for the magnetic core loop of an electrical transformer. The retaining band includes a locking mechanism to hold it in place around the core. The locking is accomplished by overlapping the ends of the band, cutting a pair of incisions in the overlapping region which extend from the sides of the band inwardly, and then bending the resulting tab(s) inwardly. If desired, the tabs can be spot welded to provide added locking force.

Abstract: A high resolution encoder having a relatively high number of magnetic pole pairs with a magnetic flux strength sufficient for use in high resolution applications. Magnetic pole pair spacing varies from about 0.01 inch to about 0.1 inch with each magnetic pole pair having a magnetic flux in the range of about 2 gauss to about 700 gauss at a distance of 0.036 inch at a temperature of +20 degrees centigrade. This high resolution encoder is especially well-suited for use with magnetically encoded targets in sensor bearings.

Abstract: 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.

Abstract: An armature and shaft assembly useful in gauges and stepper motors is encapsulated for ease in manufacture and diversity of application, the capsule being suitable for sealing in dampening fluids and for allowing magnetization of the armature after assembly of the capsule, providing protection against contamination by dust, etc.

Abstract: 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 of

Abstract: A process for manufacturing a polymeric encapsulated "E" core transformer, a polymeric encapsulated "C" core transformer, and a polymeric encapsulated toroidal shaped transformer, said process requiring considerably less time to complete than do conventional transformer manufacturing processes.

Abstract: A number of rare earth-cobalt permanent magnet segments are temporarily secured together by means of a tool. Before securement the segment surfaces at each interface are pre-tinned. A solder pre-form in the shape of a "wagon wheel" rests on one transverse end of the magnet so that the spokes of the pre-form overlie the interface joints. The magnet is then lowered into a gradually heated glycerine bath until the solder melts and directly flows over each interface. Upon slow cooling of the cylinder, metallurgical bonding is effected between the various segments of the magnet.

Abstract: The construction of a yokeless permanent magnet structure with a cavity, which structure comprises a single layer of abutted magnetic prisms, is performed by first utilizing a reference point "F" for the construction such that point F lies on a equipotential line of zero potential. The point F must, furthermore, be selected so that it lies on a line which divides the magnetic flux within the cavity into two separate loops or parts. Beginning from point F, the magnet structure is then constructed from a series of precisely abutted prisms of magnetic material which form a cavity with a predetermined, uniform polygonal cross section. Using well known boundary value conditions between the cavity and the various prisms of the magnetic material, as well as the restriction that the exterior surface of the permanent magnetic must be an equipotential surface of zero potential, each prism, in turn, is constructed, until the entire permanent magnet is completed.

Abstract: A print actuator for a dot matrix printer has a stator with a frame, at least two ferromagnetic poles and at least one permanent magnet; and at least one electromagnetic coil surrounding the magnet. The magnet can generally hold an armature in a home position by its magnetic flux until the coil is energized at which point the magnetic flux of the magnet is neutralized by the magnetic flux of the coil and the armature is substantially released of influence from the magnet's hold.

Abstract: The face plates of a drift tube have their joints with a central cylindrical body sealed by utilizating two metallurgical techniques. The first technique involves the soldering of interface surfaces at the joints between the face plates and the body. The soldered joint prevents the entry of electroplating solution into the interior of the drift tube during a second metallurgical procedure involving the electroformation of a copper strap around the joint which provides a permanent seal against leakage of coolant from the drift tube while offering excellent electrical and thermal conductivity across the surface of the drift tube.

Abstract: A high resolution encoder having a relatively high number of magnetic pole pairs with a magnetic flux strength sufficient for use in high resolution applications. Magnetic pole pair spacing varies from about 0.010 inch to about 0.050 inch with each magnetic pole pair having a magnetic flux in the range of about 2 gauss to about 700 gauss at a distance of 0.036 inch at a temperature of +20 degrees centigrade. This high resolution encoder is especially well-suited for use with magnetically encoded targets in sensor bearings.

Abstract: 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.

Abstract: 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.

Abstract: A method of forming slots in the metal coupling disc (e.g., the armature or rotor) of an electomagnetic coupling such as a clutch or brake. The method is carried out by effecting relative movement between the coupling disc and a laser beam to cause the beam to melt portions of the disc and thereby form slots through the disc. The laser beam is defocused relative to the disc in order to enable a relatively low powered laser beam to form relatively wide slots in the disc. A pressurized jet of gas is directed against the disc immediately adjacent the beam and acts to blast metal from the slots and assist in the formation of wide slots.

Abstract: The invention pertains to a gyromagnetic device such as an insulator, operating at ultra-high frequencies (1-40 GHZ). The assembling of gyromagnetic devices requires high-precision positioning, generally obtained by bonding. In the isolator of the invention, the conducting core and the two ferrite wafers are held by two internal ground plates which form a positioned assembly, one of the plates being provided with tongues which position the parts and which fit into slits in the other ground plate. The assembling is done by stacking, inside the casing, a pressure washer, the magnet, the pre-positioned assembly and the base plate, and by closing the device with a single electric weld.

Abstract: A hermetically sealed magnetic sensor for detecting variations in a magnetic field has a sensor element with an output terminal for detecting variations in the magnetic field and generating a signal. An output wire is connected with one end to the terminal for outputting a respective signal from the sensor element. A case having an opening on a side close to the output wire contains the sensor element. A first thermosetting resin fills the case for covering the sensor element. A second thermoplastic resin hermetically seals the opening in the case.

Abstract: The invention is in the field of electromagnetic transducers. The sensor according to the invention includes an electrical winding 2 mounted on a carcass 1 hollowed with a cavity 7 which receives a metal pole piece 5 and a permanent magnet 6. According to the invention inclined ribs 20 are formed in the cavity 7 in order to constitute a means of progressively locking the magnet by the wedge effect during the insertion of this magnet and of the pole piece into the cavity. It is thus possible to accurately adjust the distance d which separates the end 21 of the pole piece from a reference surface 22 of the carcass 1. Application to the production of a shaft speed sensor or a wheel speed sensor for a motor vehicle.

Abstract: A method of forming slots in the coupling disc (e.g., the armature or rotor) of an electromagnetic coupling such as a clutch or brake. The method is carried out by effecting relative movement between the coupling disc and a laser beam in such a manner as to cause the beam to trace the perimeter of the slot to be formed and to cut a slug of material from the disc. Also disclosed are coupling discs in which opposing side walls of the slots converge toward one another and in which the side walls are concentric but obliquely inclined.

Abstract: A bakeable evacuative fabrication assembly for the production of permanent agnets formed by assembling discrete magnetic elements on a core, enclosing such assembly in a close-fitting container, providing end closures on said container, and providing a one of said end closures with a sealably closeable cold mold vent means.

Abstract: 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.

Abstract: A technique for assembling a transformer core from two separate core components uses a thermo shrinkable elastomer band or tubing in place of the more conventional glues and metallic clips to secure the component into a unitary structure. A thermo shrinkable mylar plastic tubing is placed around a periphery of a core formed by abutting two separate core components together so as to form a closed magnetic path. Application of heat shrinks the tubing and secures the two separate core components into one unitary core structure.

Abstract: A method of manufacturing the adapter of a multipole slab includes assembling simultaneously a stack of alternating plates of magnetic steel and non-magnetic steel, a solder and a thin-wall steel container of which the walls sealingly enclose the stack of the plates and the solder. Then the container with the stacked plates and solder therein is heated to a soldering temperature, and subsequently cooled. Then the walls of the container adjoining the edges of the stacked plates are removed.

Abstract: Apparatus for assembling a pair of high strength magnets and the common pole piece into a unit for use in a disk drive includes a bed with a channel in which the magnets can slide or translate, and a stop centrally located in the channel to prevent execessive impact between the magnets as they slide under the force of mutual attraction toward each other. A recess in the bottom of the channel below the stop is adapted to receive the pole piece, and the attractive force between the pole piece and the magnets firmly attaches the magnets to the pole piece in the desired location after they have been properly positioned with respect to the pole piece by interaction of the stop and channel walls with the magnets.

Abstract: A method of making a magnet arrangement including a cylindrical magnet, pole shoes surrounding and resting against the magnets, the pole shoes formed of hollow cylinder sections, and two cover plates placed on the end faces of the magnet and the pole shoes, wherein the cover plates are connected to the pole shoes. The inner surfaces of the pole shoes facing the magnet have, before being placed on the magnet, a radius different from the radius of the outer cylindrical surface on the magnet. The magnet arrangement is obtained by placing the pole shoes against the magnet, pressing the pole shoes against the magnet until the radius of the outer surface of the magnet and the radius of the inner surfaces of the pole shoes are equal, and welding the cover plates and the pole shoes together. In the resulting magnet arrangement, the finish of the magnet must not need narrow tolerances, and it is ensured that no air gaps exist between the inner surfaces of the pole shoes and the outer surface of the magnet.

Abstract: A method of insulating a field coil of an electric traction motor, comprising the steps of encapsulating the coil in flexible ground insulation, temporarily mounting the insulated coil on a field pole piece, wrapping heat shrinkale material around the perimeter of the insulated coil, said material being so composed, oriented, and applied as to shrink irreversibly, when subsequently heated, in a direction tending to constrict the whole outside perimeter of the insulated coil, attaching the base of the pole piece to a concave surface of the magnet frame of the motor in a manner that compactly clamps the coil between the frame and an overhanging distal end of the pole piece, heating the perimeter wrap so that it shrinks appreciably and tightly binds the underlying ground insulation, thereby counteracting any tendency of the ground insulation to become slack on the outside of the coil when the coil was clamped in place, and filling any remaining voids inside the ground insulation with varnish or resin in a conven

Abstract: Disclosed is a method of manufacturing an electromagnetic member having properties of magnetic anisotropy as well as electrical conductivity, comprising the steps of coating an outer circumferential surface of each of a plurality of magnetic strips with a first electrically conductive material to a predetermined thickness to thereby form a plurality of composite magnetic strips, binding the plurality of composite magnetic strips, and filling spaces among the plurality of composite magnetic strips in the bundle with a second electrically conductive material substantially the same as the first electrically conductive material. By this method, a mechanically strong electromagnetic member can be obtained in which adjusting the thickness of the first electrically conductive material, the ratio between the magnetic property and the electrically conductive property can be easily adjusted by adjusting the thickness of the first electrically conductive material and blow-holes can be prevented from being generated.

Abstract: A method of forming non-magnetic barriers in the coupling disc (e.g., the armature or rotor) of an electromagnetic coupling such as a clutch or brake. The method is carried out by moving the disc relative to a laser beam which cuts a slot through the disc. In one embodiment, the slot is filled throughout its entire length by non-magnetic material, the filling being effected by continuously advancing a non-magnetic wire toward the laser beam to cause the wire to be melted by the beam and to flow into the newly formed slot. In another embodiment, the wire is advanced intermittently to form short non-magnetic bridges beween relatively long slots.

Abstract: An encapsulated magnet device which is made from bar stock having a hole drilled in, which receives a magnet, and thereafter the hole is plugged with a cap or plug of like material and subjected to a fusion process so that a magnetic device is obtained which is finely balanced and which is inert to the environment in which it is utilized. The method of fabricating the magnetic device of the invention comprises drilling out bar stock, inserting a magnet, closing the bore with a plug of like material, fusing the plug to the surrounding bar stock and thereafter milling or machining the encapsulated magnet member to the desired configuration.

Abstract: A magnetic roll for electro-photographic copy machines is provided with a carrier to which strip-shaped permanent magnetic components are fastened in an axial direction. Recesses are provided in the carrier having a cross-section larger than the magnetic components so as to permit selective radial, tangential and pivotal movement for universal positioning of the components within the recess. The components are selectively oriented to provide a predetermined induction value as measured at a predetermined distance outwardly of the carrier or with respect to adjacent poles as determined by discretely located Hall probes. The permanent magnetic components are fixed in the prescribed orientation by an injection moldable plastic material such as a plastic foam.

Abstract: A process for manufacturing a core used for an electromagnet is disclosed. First, one connecting structure and a number of core elements having sides of the same shape are prepared. Next, a number of core elements are radially disposed round and about the connecting portion. In this case, an engaging portion provided on each of core elements is brought into engagement with a connecting portion provided on the connecting structure whereby the core elements are positioned relative to the connecting structure. Next, the connecting structure and a number of core elements are integrally connected. Thereby a core is finished.

Abstract: A method and apparatus for pressing magnetic powder in a toroidal-shape we in a radial magnetic field. A magnetic flux is produced and carried by a die rod through the axial center of toroidally-shaped magnetic powder. An annular portion coaxially surrounding the die rod and magnetic powder is connected to a yoke member which carries the magnetic flux back to the magnetic flux producing means. This completes the magnetic circuit, and creates a radial magnetic field across the toroidally-shaped magnetic powder between the die rod and the annular portion. This radial magnetic field aligns the granules of the toroidally shaped magnetic powder during pressing.

Abstract: A core gap spacing arrangement for a transformer includes a length of twisted wire pair. The twisted pair has a relatively low packing density and is therefore compressible over a large range by using relatively low compression forces, resulting in greater ability to accurately adjust the inductance of the transformer primary winding.

Abstract: A disc drive arrangement including RW head actuator driven by an improved voice coil motor, having ceramic back-magnets which are subdivided to give improved magnetic characteristics and operation (increased working flux and an increase in efficiency and effective power acceleration for given current--e.g., thus decreasing "access time").

Abstract: In an induction welding process for metal tubing, an impeder having a fiberglass sleeve and an exposed ferrite core is used to concentrate the flow of current along a seam to be welded. The sleeve at its upstream end is connected to a brass fitting which couples a source of coolant to the impeder. The sleeve is loosely connected to the ferrite core by a pin and the ferrite core is exposed and protrudes from the downstream end of the sleeve, thereby allowing the ferrite core to be placed in close proximity to the welding point of the metal tubing. As coolant flows over the exposed end of the ferrite core, it both cools and cleans the exposed end of the ferrite core.

Abstract: A bubble memory device comprises an insulating substrate holding a bubble memory chip secured thereto, X- and Y-direction driving coils wound on the insulating substrate for providing an in-plane rotating filed to the chip, a lead frame secured to edge portions of the insulating substrate, and magnet blocks disposed above and below the coils and including permanent magnets and field homogenizer plates for providing a bias field to the chip. The magnet blocks are molded together with the insulating substrate, coils and lead frame.

Abstract: A method of manufacturing a plate-shaped permanent magnet (7) which is to be arranged in an air gap of a core (1) for a transformer or choke coil and which consists of a number of permanent magnetic portions (29) which are made of a metal alloy having a high magnetic remanence and which are magnetized perpendicularly to the plane of the plate. A plate (11) of the alloy is fixed between two insulating foils (13, 15) after which this assembly is arranged on a flat backing (17) and is rolled in two mutually perpendicular directions (25, 27) by means of a cylinder (19) whose outer surface is provided with grooves (23). The plate (11) is thus very simply fractured to form a very large number of portions (29).

Abstract: In a transformer for use in a receiver set, a non-magnetic material arranged in part of a closed magnetic path established by a magnetic core is made of a plastic material such as paper mash or silicon putty. The non-magnetic material is pressurized and deformed so as to set the inductance of a coil mounted on the magnetic core to a predetermined value.

Abstract: A speaker comprises a voice coil placed in an air gap between a center pole and a plate wherein a specific ferromagnetic material obtained by forming fine crystalline grains is used on at least one of the surfaces of the center pole and the plate which respectively face the voice coil, thereby providing a speaker having low distortion.

Abstract: A delay line having an inductive component in which inductive windings are made on multiple post bobbin units to maintain spacing and alignment. Two multiple bobbin units are collectively wound and then secured together with the bobbins interfitting to form a rigid, precisely aligned element, with the wires from each bobbin positioned for ease of connection. The inductive component is mounted on the base of a dual in-line package (DIP), capacitors are secured in the inductive component and the electrical connections are made to connect the inductors and capacitors to the contact pins of the DIP. The assembly is then potted or otherwise enclosed for protection.

Abstract: A shoe insole comprising (A) a coarse mesh-like woven cloth backing made of monofilaments of a vinylidene chloride-type polymer, (B) a honeycomb-woven cloth intermediate layer made of monofilaments of the vinylidene chloride-type polymer, (S) a sheet prepared by coating a latex containing activated carbon powder, copper powder and magnetic powder on a non-woven cloth made of staple fibers of the vinylidene chloride-type polymer and/or a vinyl chloride-type polymer and heat-treating the coated cloth, and (D) a fine-woven cloth surface layer made of monofilaments of the vinylidene chloride-type polymer, the cloths (A), (B), (S) and (D) being laminated in order and the peripheral edge of the laminate being welded, and a process for producing the same.

Abstract: A method of boring a hole through a magnet made of an intermetallic compound, characterized in that the hole is formed by a laser machining. The magnet may be reinforced by impregnation with a nonmagnetic material such as a high polymeric substance or a metal having a low melting point before the hole is bored through the magnet by laser machining.

Abstract: A method for measuring stresses or forces by measurement of variations of the magnetic properties of ferromagnetic substances under stress conditions. This is carried out by providing a ring of ferromagnetic material between two parallel faces on or between which the stresses are exerted, the ring defining a magnetic circuit, providing an electric coil within and around the ring, passing a current through the coil and measuring changes in the properties of the current to measure variations in the magnetic properties of the ring.

Abstract: A method of making a permanent magnet magic ring structure. An annular cyder made from a magnetically hard material is uniformly magnetized in a direction perpendicular to its major axis. The cylinder is cut into eight or sixteen or 32 or more segments. Various segments are interchanged with other segments to produce a magic ring which has an intense uniform magnetic field within a central working space.