Abstract: Procedures for designing magnets, including superconducting magnets, shim magnets, and gradient magnets for magnetic resonance systems, are provided. The procedures involve the use of a simulated annealing procedure in which weighted spherical harmonics are included in the procedure's error function. The procedure has resulted in the development of previously unknown magnet designs. In particular, superconducting magnets have been designed which include at least one coil in which the current flow is opposite to that in adjoining coils. Such reversed flow in combination with a relatively large number of coils, e.g., more than 6 coils, have enabled the development of short, yet homogeneous, whole body magnets for use in magnetic resonance imaging (MRI).

Abstract: The present invention is directed to an electromagnetic clutch including a U-shaped annular magnetic housing and a coil disposed within the annular magnetic housing. A connector connects a pair of end portions of the coil to a pair of covered lead wired connected to an external electric circuit having an electric power source. A pair of channel-shaped terminals are provided at one end of the pair of the covered lead wires, respectively. The connector includes a box member comprising a first groove, a second groove, a pair of third grooves, and a pair of fourth grooves formed at an inner bottom surface thereof The first and second grooves are arranged to intersect with the third and fourth grooves in right angles. A pair of end portions of the coil are stably laid on an inner bottom surface of the first groove and a pair of lead wires oppositely extending from a diode are stably laid on an inner bottom surface of the second groove.

Abstract: A laminated superconducting magnet includes a multilayer short-circuit superconductor group 2 formed by uniting superposed hollow superconducting plates, and an exciting coil 3 for inducing a current from an external power source 4 to the multilayer short-circuit superconductor group 2 for operation in a permanent current mode. Even if some of the superconducting plates are quenched, the other normal superconducting plates share the excess current temporarily. Therefore, the entire superconducting magnet is not quenched.

Abstract: A superconducting annular electro-magnet for MRI purposes includes an annular winding within which a generally cylindrical space is provided. The winding adjacent each end of the space is formed with a chamfer to provide flaring at each end of the space.

Abstract: The modular relay has a base (1) on which a relay system (2, 3, 4) is constructed, as well as a printed circuit board (6) which stands upright on the base. Contact elements (41c, 42c, 43) of the relay are directly connected to flat connectors in the base, via conductor elements. Further conductor elements in the base likewise form flat connectors as connections for a modular circuit which is arranged on the printed circuit board. All conductor elements of the base additionally form solder connecting pins (51b to 56b), which are integrally formed, which all emerge in a row on one side wall of the base, and which are soldered to the printed circuit board in the lower edge region of said printed circuit board. This results in a compact modular structure for a relay having a maximum number of connecting elements, the allocation of these connecting elements being variable for different modular circuits.

Abstract: An improved relay includes a base (20) integrally molded defining a pair of notches (24) for matingly receiving a mounting structure (26) comprised by a motor assembly (10) of the relay, so as to determine the relative positions of the motor assembly (10) and the base (20) with a high degree of reliability. The other components of the relay are similarly secured in corresponding predetermined positions by fitting within other mounting structures molded into the base member (20).

Abstract: A door lock assembly includes a lock body, a latching unit, an electromagnetic driving device, and a linkage mechanism. The latching unit has a locking pin which is mounted slidably in the lock body. The electromagnetic driving device has an inner tube and an outer tube which is connected to the lock body, and first and second insulating ring members connected respectively to two ends of the inner tube and received in the outer tube. An electric coil is mounted around the inner tube. The first ring member has two annular projections and an annular groove formed between the annular projections. The end wires of the electric coil are extendible respectively into the annular groove through the axial hole and the axial notch of the second annular projection in order to connect an end of the electric wire. The linkage mechanism has a first end portion which is received in the inner tube and a second end portion which abuts against a lower end of the locking pin of the latching unit.

Abstract: A magnetic resonance imaging (MRI) magnet includes different-diameter, longitudinally-proximate, first and second coil form segments. First and second superconductive coils are wound, respectively, around the first and second coil form segments. A first spacer ring is attached to the first coil form segment and longitudinally abuts a lateral side of the first superconductive coil, and a second spacer ring circumferentially surrounds and is attached to the second coil form segment and longitudinally abuts a lateral side of the second superconductive coil. Two or more circumferentially-spaced-apart plate members are attached to, and extend radially outward from, the first and second spacer rings.

Abstract: An apparatus and method for bending magnetic flux in a magnetic circuit are disclosed. A means for conducting a substantially planar electric current is placed in the path of the flux of a magnetic circuit. Current is then caused to flow in the conducting means, causing the magnetic flux in the magnetic circuit to deviate from its original path. A preferred embodiment of the invention is described wherein a series of coils are used to form both the planar conducting means and a partial flux conduit for coupling the flux bending apparatus to the magnetic circuit. Specific applications of the invention are disclosed in relation to magnets for use in magnetic resonance imaging applications, and magnets for use in dual dipole particle accelerator applications.

Abstract: A process for manufacturing superconducting magnetic coils from strain-tolerant, superconducting multi-filament composite conductors is described. The method involves winding the precursor to a multi-filament composite conductor and an insulating material or its precursor around a mandrel in order to form a coil, and then exposing the coil to high temperatures and an oxidizing environment. The insulating material or its precursor is chosen to permit exposure of the superconductor precursor filaments to the oxidizing environment, and to encase the matrix-forming material enclosing the filaments, which is reversibly weakened during processing.

Abstract: A magnetic structure generating a substantially uniform magnetic field within a region of interest comprising at least one pair of magnetic wedges of substantially identical shape arranged symmetrically about a first axis and abutting one another along a common edge. Each magnetic wedge has a first side and a second side which terminate at the common edge. The first wedge of each pair is positioned to define a first angle between the first side and the first axis and a second angle between the second side and the first axis, and is uniformly magnetized in a direction relative to a second axis (perpendicular to the first axis) which is a function of the sum of the first and second angles.

Abstract: A voice coil actuator is disclosed having a housing, a pole piece, a magnet structure and a coil. The housing is cylindrical and defines a vertical axis. The housing further defines a base portion, an outer wall extending axially from the base portion and a top plate extending radially inward from the outer wall. The base portion defines an annular channel coaxial within the base portion. The pole piece is coaxially disposed within the housing. A gap is defined between the top plate and the pole piece. The coil is moveably suspended coaxially within the gap. The magnet structure is fabricated from rectangular shaped radially magnetized permanent magnets. The magnets are arranged in a polygonal shape and disposed in the channel.

Abstract: The magnetic states of MR reproducing heads are reinitialized during media drive manufacturing by applying initializing magnetic fields to the transducers after they have been manufactured and incorporated into media drive assemblies.

Abstract: A latching electromagnet is provided. The electromagnet (300) includes a core (305) having a pole face, a coil of windings (325), and an armature (330). Advantageously, the core has a geometry that locally increases the magnetic flux density to saturation levels.

Abstract: Solenoid apparatus having a substantially cylindrical casing, an electro-magnetic coil, a plunger axially aligned and slideably mounted to the casing, a housing hermetically mounted to an end of the casing and a vacuum source operatively coupled to the external port. The plunger has a first end extending outside of the casing, a second end and an internal passage extending from the first end to the second end. The electro-magnetic coil is selectively energizeable for moving the plunger between a first position and a second position. The housing corresponds to the plunger second end to define an inner chamber which encloses the plunger second end. The housing includes an external port connected to the inner chamber so as to provide an unobstructed pathway from the external port to the first end of the plunger via the internal passage and the inner chamber regardless of whether the plunger is in the first position, the second position or therebetween.

Abstract: Proposed is an improvement in a magnet assembly of an MRI instrument of the permanent magnet type comprising a pair of permanent magnets facing each other and forming a magnet gap therebetween. A pair of pole pieces each of which are mounted on one of the permanent magnets and a pair of gradient-field coils each of which are mounted on one of the pole pieces where both the pole pieces and coils face the gap. With an object of the invention to cancel the adverse influences caused by the residual magnetization of the pole pieces by the gradient magnetic field generated in the gradient-field coils. The invention proposes providing a pair of magnetic-field compensation members each on one of the gradient-field coils so that the residual magnetization in the compensation members generates a magnetic field which is compensatory for the magnetic field due to the residual magnetization in the pole pieces.

Abstract: A superconducting device, such as a superconducting rotor for a generator or motor. A vacuum enclosure has an interior wall surrounding a cavity containing a vacuum. A superconductive coil is placed in the cavity. A generally-annularly-arranged, thermally-conductive sheet has an inward-facing surface contacting generally the entire outward-facing surface of the superconductive coil. A generally-annularly-arranged coolant tube contains a cryogenic fluid and contacts a generally-circumferential portion of the outward-facing surface of the sheet. A generally-annularly-arranged, thermally-insulative coil overwrap generally circumferentially surrounds the sheet. The coolant tube and the inward-facing surface of the coil overwrap together contact generally the entire outward-facing surface of the sheet.

Abstract: A casing with multiple bar magnets attached to the inner side of a casing back panel. A non-magnetic cover encloses the magnets in the casing and provides a flat surface for engaging tools and other objects. The casing has handles on the casing side panels to permit easy carrying and a means for hanging the casing in a variety of work locations.

Abstract: In an electromagnetic relay in which a contact mechanism 50 provided on a base 10 is driven by a card 60 which slides and moves in parallel to the axis of an electromagnet block 20 provided in the base 10 as the electromagnet block 20 is magnetized and demagnetized, the base 10 comprises a guide portion 17 for restricting the card 60 in its position. This prevents variations in the performance characteristics so that high productivity and long service life of contacts can be obtained.

Abstract: An earth leakage breaker has a case, a handle protruding from the case, a cradle for determining stable positions of the handle, and a movable finger including a movable contact at a bottom portion of the movable finger. The movable finger is pivotally jointed to the handle at a protrusion provided on a lower side of the handle. An extension spring spans between the cradle and the movable finger, and a top-end swinging trigger plate is provided for engaging the cradle. The trigger plate has a fulcrum at a bottom portion thereof, and a test button and a leak trip solenoid are adjacently arranged at a top portion of the case, with the leak trip solenoid having a trip piece engaged with a contact portion formed on a top portion of the trigger plate for effecting circuit breaking due to a leak.