Abstract: This specification discloses a method of manufacturing a magnet roller having the step of disposing a plurality of pairs of magnetic poles each comprising the starting magnetic pole and terminal magnetic pole of a magnetic line of force on the peripheral surface of a cavity in a metal mold in which a resin magnet is molded and oriented so that straight lines passing through the starting magnetic poles and terminal magnetic poles of the pairs of magnetic poles are substantially on the same plane and extend through the cavity substantially in parallelism to one another, molding and orienting a resin magnet material poured into the cavity while applying a plurality of magnetic lines of force for orientation into the cavity in the same direction, thereby obtaining a molded article having at least four magnetic peaks, and the step of inverting part of the magnetic properties of the magnetic peaks of the molded article so that the magnetic properties of the adjacent magnetic peaks differ from each other.

Abstract: An electromagnetic actuator for driving a hammer of an impact printer includes a solenoid and an armature which is attracted thereby. In a state of standby for printing, no current is supplied to the solenoid, and the armature holds the hammer in an urge-accumulated state. Upon supply of a current to the solenoid, the armature is attracted toward the core, and the hammer head in that state is released so as to be impacted against a platen, thereby effecting a printing operation. If the current is shut off with the armature attracted by the core of the solenoid, the armature returns to its original position. To effect a speedy return at that juncture, a return leaf spring having a resilient bent portion is interposed between the core and the armature.

Abstract: An actuator is disclosed, in which an movable armature and a permanent magnet mounted on a stationary yoke are disposed to face each other with a small gap. The armature has at least one pair of protruding poles which are movable along a predetermined path. The permanent magnet comprises plural pairs of juxtaposed magnetic pieces whose polarities are opposite to each other. The plural pairs of magnetic pieces are arranged in juxtaposition with each other at positions adjacent to the path of the corresponding protruding pole so that adjacent two magnetic pieces of adjacent two pairs have the same polarity with each other. The permanent magnet generates such a magnetic pattern that the amount thereof gradually decreases from both ends of the path of each protruding pole towards the boundary of the magnet pieces of the corresponding pair to avoid the influences due to the reluctance torque and the drive torque.

Abstract: A superconducting switch pack has six switch elements arranged with three in each of two planes. Each switch element is made of a length of cupro-nickel matrix multi-filamentary superconducting wire which is formed into a serpentine shape so as to be bifilar. Primary and back-up heater elements are positioned between the planes of switch elements, and all of the switch elements and heater elements are encapsulated in a solid resin body, with their leads extending outside of the body for connection to electrical circuits. This construction results in a stable superconducting switch pack which is non-inductive, has a high current carrying capability and off resistance. This reduces cryogen boil off of the superconductive circuits connected to the switch pack and makes the switch pack particularly suited for the shim coils of an MR magnet. Each section of the switch pack can also keep magnetic field drifts of the individual superconductive coils to less than 0.

Abstract: A high-speed superconducting switch and method. A body of superconductive material has a primary conductive plane through which primary current flows in an electrical circuit. Control current is conducted through the body of superconductive material in a direction which is angular with respect to the primary conductive plane. When control current flows through the body of superconductive material the primary current does not flow through the body, and when the flow of control current ceases, flow of the primary current resumes.

Abstract: A superconductor for magnetic field shield comprising closed-ring disc-shaped superconductive magnetic field shielding members and spacing members having the same shape as that of the magnetic field shielding member and alternately laminated with the shielding members, the superconductor for magnetic field shield being characterized in that the shield has an extremely superior and stable magnetic field shielding effect without any secular reduction of the shielding effect and capable of providing a large shielding space using a minimum amount of material.

Abstract: A electromagnetically shielded and insulated housing assembly (500) is provided having a housing member (200) and a flexible member (100). The housing member has an open side (240) and enclosing sides (215). The flexible member has a layer (110,180,185) of conductive material disposed on selected areas of each opposing side (150,155). The conductive areas are electrically connected by a plurality of conductive feed-throughs (120,115). One side of the flexible member also has adhesive areas (130,125), which are separated from the conductive area. The conductive area of the flexible member is placed over the open side of the housing member and covers it, and thereby electrical contact between the housing and the peripheral edges (250) of the open side is produced. Upward folding of the flexible member bonds the adhesive areas to the opposed enclosing sides of the housing. The other side of the flexible member is connected to a main ground, thereby electromagnetically shielding the housing assembly.

Abstract: A magnetic field generating device provides a useful magnetic field within a specific retgion, while keeping nearby surrounding regions virtually field free. By placing an appropriate current density along a flux line of the source, the stray field effects of the generator may be contained. One current carrying structure may support a truncated cosine distribution, and it may be surrounded by a current structure which follows a flux line that would occur in a full coaxial double cosine distribution. Strong magnetic fields may be generated and contained using superconducting cables to approximate required current surfaces.

Abstract: Permanent magnets for producing an intense field. A main magnetic circuit comprises two magnets (1, 1'), two pole pieces (2, 2') and a yoke (3). Two additional magnets (6, 6') of opposite magnetization reinforce the field in the air gap (5) while extending into the latter between edges (25, 25', 26, 26', 27, 27', 28, 28') of magnets (1, 1') and pole pieces (2, 2'). Application to imaging by magnetic resonance (tomography).

Abstract: A low thermal conductance support for a radiation shield in a magnetic resonance magnet is provided. Spacer means are situated partially in apertures in a cylindrical coil form having superconducting windings supported from a vacuum vessel. The spacer means are spaced away from the aperture walls and are secured at one end to the coil form. The spacer means protrude radially beyond the coil form surface and contact a radiation shield. The length of the spacer means is greater than the distance between the surface of the coil form and shield thereby increasing the thermal conduction path length between form and shield.

Abstract: A field coil assembly for an electromagnetic clutch includes a coil of current conducting wire, a cap covering an axial end of the coil, a bobbin covering the opposite axial end, a terminal post formed integrally with the bobbin, a terminal inserted within the post, a connector sleeve covering the post and terminal blades, and a coil housing in which the coil is located and retained mechanically. The ends of the coil wire are lead through the holes in the bobbin and supported on bosses molded in the bobbin. The terminals are fitted within apertures in the bobbin, engage the wire ends, cut through the wire insulation, draw a residual portion of the lead wire within the terminal post, and form an electrical contact between the wire and the terminal end. Before the terminal is inserted into the post, the wires and wire supports integral with the post are sheared to a correct length by a knife passing over the top surface of the post.

Abstract: A method of longitudinally severing a longitudinally symmetrical annular core of ferromagnetic material into two parts. By means of a laser, two lines of recesses are inscribed in the surface of the annular core substantially in the longitudinal direction. The recesses are shaped so that the resulting weakening of the annular core along the lines of recesses causes it to spontaneously fracture into two parts along such lines.

Abstract: In circular conductor plates having radial slits alternately stacked with spirally wound coils continuously connected in order and supplied with comparatively low frequency AC current, eddy currents generated in peripheral direction are concentrated along the radial slits around central holes of the conductor plates, so as to induce concentrated AC magnetic fluxes in those holes. As a result, an intense AC magnetic field can be efficiently obtained by a comparatively small driving AC current in comparatively low frequency range.

Abstract: A magnetic resonance imaging magnet has a solenoidal superconducting winding producing a magnetic field and defining an examination region within a bore thereof. The examination region receives a body to be examined. The solenoidal superconducting winding generates a quasi-static magnetic field for aligning atomic nuclei in the body being examined. A two-fold or minimally symmetric ferromagnetic shield has a pair of magnetic flux return paths positioned on opposite sides of the solenoidal superconducting winding for reducing the magnetic field intensity in a region proximate to and outside of the solenoidal superconducting winding. A magnetic field inhomogeneity compensating system reduces magnetic field inhomogeneities introduced into the magnetic field within the examination region by the minimally symmetric ferromagnetic shield to provide a highly uniform quasi-static magnetic field within the examination region.

Abstract: An electro-magnetic shunt trip device has a pair of aligned plungers 10,24. A first plunger 19 acts on an operating member 20 which is pivotal and connected to a spring 18. The second plunger 24 is manually displaceable. A further spring 26 is located between the plungers. The plungers are part of a magnetic circuit, with a magnetic field being generated by a permanent magnet 30 and an electro-magnet 32. The permanent magnet and the electro-magnet generate fields of opposite polarity. If there is no current in the electro-magnet, the field provided by the electro-magnet will be sufficiently strong to hold the two plungers together. The spring 18 acting on the operating member will cause it and the plungers to move, so that the operating member is in a non-tripping position.

Abstract: Superconducting persistent current rings are mass produced by passing each uperconducting ring through a tapered magnetic field that is tapered in strength so that when each ring passes through the maximum magnetic field of the tapered magnetic field which is above the critical field of the tapered magnetic field the superconducting ring becomes normal thereby admitting all of the flux to which its cross section is exposed. When the ring is passed to a region of field lower in strength than the critical field, the ring becomes superconducting again and traps the flux to which its cross section is exposed.

Abstract: A coil (33, 33a) is wound on a bobbin (22, 22a), one flange (24, 24a) of which has an end surface provided with a central projection (26, 26a) on its center and first and second end projections (27, 27a; 28, 28a) on its opposite end portions respectively, thereby to define first and second cavities (29, 29a; 30, 30a). First and second electrodes (31, 31a; 32, 32a) are provided to extend from the first and second end portions of the flange toward its side surface. First and second terminals (34, 34a; 35, 35a) of the coil are respectively received in the first and second cavities, which in turn are filled with solder members (36, 36a; 37, 37a) to electrically connect the first and second terminals to the first and second electrodes respectively. The first and second end projections are adapted to reduce the volume of solder required for mounting the chip-type coil element as well as to substantially prevent the coil element from inclination, thereby to prevent a tombstoning phenomenon.

Abstract: A superconductive magnet for magnetic resonance imaging not requiring consumable cryogens or requiring cryogen liquid or vapor cooling of superconducting coils is provided having a resin impregnated coil of superconductor wire. Heat conductive means having a thermal conductivity greater than the resin, contact the impregnated coil along the length of at least one of the impregnated coil surfaces. A thermal radiation shield is spaced away from and surrounds the resin impregnated coil and heat conductive means. An evacuable housing is spaced away from and surrounds the shield. The housing supports the shield, heat conductive means and the impregnated coil.

Abstract: A torque motor including a frame of soft magnetic material, such as soft iron, spaced first end portions on the frame, an armature which is a magnet, spaced second end portions on the armature, a mounting member for mounting the armature on the frame for allowing motion of the armature relative to the frame, each of the end portions of the armature including a north pole and a south pole, air gaps between the end portions of the frame and the end portions of the armature, a coil mounted on the frame, and the armature being in the form of a laminate with a central layer being a rare earth magnet between outer layers of magnetic material.

Abstract: A method of magnetizing high energy rare earth alloy magnets by applying a magnetic field while heating the magnetic alloy.