Abstract: An active noise control subassembly for reducing noise caused by a source (such as an aircraft engine) independent of the subassembly. A noise radiating panel is bendably vibratable to generate a panel noise canceling at least a portion of the source noise. A piezoceramic actuator plate is connected to the panel. A front plate is spaced apart from the panel and the first plate, is positioned generally between the source noise and the panel, and has a sound exit port. A first pair of spaced-apart side walls each generally abut the panel and the front plate so as to generally enclose a front cavity to define a resonator.

Abstract: An open magnetic resonance imaging (MRI) magnet having first and second spaced-apart superconductive coil assemblies each including a toroidal-shaped coil housing containing a superconductive main coil. A generally annular-shaped permanent magnet array is associated with each coil assembly, being generally coaxially aligned with the associated coil assembly and being spaced radially inward and radially apart from the associated coil assembly's superconductive main coil. The permanent magnet arrays overcome the gross magnetic field distortions in the imaging volume of the superconductive main coils (created by the open space between the magnet's superconductive coil assemblies) to produce a magnetic field of high uniformity within the imaging volume.

Abstract: A superconductive lead assembly for a superconductive device (e.g., magnet) cooled by a cryocooler coldhead having first and second stages. A first ceramic superconductive lead has a first end flexibly, dielectrically, and thermally connected to the first stage and a second end flexibly, dielectrically, and thermally connected to the second stage. A jacket of open cell material (e.g., polystyrene foam) is in general surrounding compressive contact with the first ceramic superconductive lead, and a rigid support tube generally surrounds the jacket. This protects the first ceramic superconductive lead against shock and vibration while in the device. The rigid support tube has a first end and a second end, with the second end thermally connectable to the second stage.

Abstract: A method for making an electric motor stator. An annular disk is cut so as to create a radially-outer ring portion having slots and a radially-inner ring portion having spokes engaged with the slots. This step is repeated on additional disks. Then, the radially-outer ring portions are stacked together to form the stator outer shell, and the radially-inner ring portions are stacked together to form a multi-pole assembly with the aligned spokes forming the poles. Coils are wound around plastic sleeves which are each brought to, and placed over, a corresponding pole member. Then, the multi-pole assembly is positioned within the stator outer shell with the pole members engaging the aligned slots. Finally, the joined-together radially-inner ends of the spokes are cut to create narrow slits.

Abstract: A superconductive lead assembly for a superconductive device (e.g., magnet) cooled by a cryocooler coldhead having first and second stages. A first ceramic superconductive lead has a first end flexibly, dielectrically, and thermally connected to the first stage and a second end flexibly, dielectrically, and thermally connected to the second stage. A jacket of open cell material (e.g., polystyrene foam) is in general surrounding compressive contact with the first ceramic superconductive lead, and a rigid support tube generally surrounds the jacket. This protects the first ceramic superconductive lead against shock and vibration while in the device. The rigid support tube has a first end and a second end, with the second end thermally connectable to the second stage.

Abstract: A closed magnetic resonance imaging (MRI) magnet has a single superconductive coil assembly including a toroidal-shaped coil housing containing a pair of superconductive main coils and at least one additional superconductive main coil. A pair of generally annular-shaped permanent magnet arrays is spaced radially inward and apart from the superconductive main coils. The permanent magnet arrays allow the design of a shorter MRI magnet because the permanent magnet arrays overcome the gross magnetic field distortions in the imaging volume of the magnet (created by removing some of the additional longitudinally-outermost superconductive main coils, otherwise used in the magnet, to make the magnet shorter) to produce a magnetic field of high uniformity within the imaging volume.

Abstract: A closed magnetic resonance imaging (MRI) magnet has a single superconductive coil assembly including a toroidal-shaped coil housing containing a pair of superconductive main coils. A pair of generally annular-shaped bucking coils, carrying electric current in a direction opposite to that of the superconductive main coils, is spaced radially inward and apart from the superconductive main coils. The bucking coils allow the design of a shorter MRI magnet because the bucking coils overcome the gross magnetic field distortions in the imaging volume of the magnet (created by removing some of the additional longitudinally-outermost superconductive main coils, otherwise used in the magnet, to make the magnet shorter) to produce a magnetic field of high uniformity within the imaging volume.

Abstract: A shielded and open magnetic resonance imaging (MRI) magnet having two spaced-apart, generally toroidal-shaped superconductive coil assemblies. Each coil assembly has a coil housing containing a generally annular-shaped superconductive main and a radially-outwardly spaced-apart shielding coil carrying electric currents in opposing directions. Preferably, supplemental shielding is provided with the addition of: a generally annular permanent magnet configuration internal to, or external of, the coil housings; a generally-non-permanently-magnetized external ferromagnetic shield having at least a portion positioned longitudinally between the coil housings, an external resistive coil; or combinations thereof.

Abstract: An open magnetic resonance imaging (MRI) magnet having longitudinally spaced-apart superconductive main coils surrounded by a dewar containing a cryogenic liquid (e.g., liquid helium) and boiled-off cryogenic gas (e.g., helium vapor). A condenser is in physical contact with the boiled-off vapor and is in thermal contact with a cold stage of a cryocooler coldhead so as to re-liquefy the vapor. This allows the coils to be surrounded by a single (not double) thermal shield which allows the coils structurally to be located closer to the magnet's open space which reduces magnet cost by reducing the amount of coil needed for the same-strength magnetic field.

Abstract: An active noise control subassembly for an aircraft engine. An aircraft engine noise radiating panel is bendably vibratable to generate a canceling noise generally opposite in phase to at least a portion of the discrete tonal noise produced by the engine. A piezoceramic actuator plate is vibratable by an applied electric AC signal. The plate is connected to the panel such that vibrations in the plate cause bending vibrations in the panel and such that the plate is compressively prestressed along the panel when the panel is free of bending vibrations. The compressive prestressing increases the amplitude of the canceling noise before the critical tensile stress level of the plate is reached. Preferably, a positive electric DC bias is also applied to the plate in its poling direction to increase the amplitude of the canceling noise before the sum of the AC signal and DC bias exceeds the depolarization voltage in a direction opposite to the poling direction.

Abstract: A superconductive lead assembly for a superconductive device (e.g., magnet) cooled by a cryocooler coldhead having first and second stages. A first ceramic superconductive lead has a first end flexibly, dielectrically, and thermally connected to the first stage and a second end flexibly, dielectrically, and thermally connected to the second stage. A jacket of open cell material (e.g., polystyrene foam) is in general surrounding compressive contact with the first ceramic superconductive lead, and a rigid support tube generally surrounds the jacket. This protects the first ceramic superconductive lead against shock and vibration while in the device. The rigid support tube has a first end and a second end, with the second end thermally connectable to the second stage.

Abstract: A superconductive lead assembly for a superconductive device (e.g., magnet) cooled by a cryocooler coldhead having first and second stages. A first ceramic superconductive lead has a first end flexibly, dielectrically, and thermally connected to the first stage and a second end flexibly, dielectrically, and thermally connected to the second stage. A jacket of open cell material (e.g., polystyrene foam) is in general surrounding compressive contact with the first ceramic superconductive lead, and a rigid support tube generally surrounds the jacket. This protects the first ceramic superconductive lead against shock and vibration while in the device. The rigid support tube has a first end and a second end, with the second end thermally connectable to the second stage.

Abstract: A horizontal axis clothes washing machine. A rotatable clothes basket has a generally longitudinally extending and generally horizontally disposed axis of rotation. The clothes basket is rotatably attached to a generally surrounding first member (which is a tub). A second member (which is a cabinet) generally surrounds the tub. At least two spaced-apart tub suspension subassemblies each include a cylinder, a rod, a piston, and a spring. The cylinder is attached to one of the first and second members. The rod has a first end positioned within the cylinder and has a second end attached to the other of the first and second members. The piston is positioned within the cylinder and is attached to the first end of the rod. The spring is positioned within the cylinder between the first and second ends of the rod. Preferably, a pair of balance rings are attached to the clothes basket.

Abstract: A superconductive rotor, such as an electric generator rotor, has a cylindrical-shaped solid (e.g., iron) core having a pair of diametrically-opposed and longitudinally-extending slots. A longitudinally-extending, racetrack-shaped superconductive coil surrounds the solid core and has straight portions located in the slots. A longitudinally extending, racetrack-shaped thermal shield generally encloses the superconductive coil and has generally straight portions located in the slots. The thermal shield is generally spaced apart from the superconductive coil and from the solid core. A pair of end shafts are each attached to the solid core and are spaced apart from the thermal shield. One end shaft has a cryogen transfer coupling for cooling the superconductive coil, preferably with gaseous helium.

Abstract: A superconducting device, such as a superconducting rotor for a generator or motor or a superconducting magnet for a magnetic resonance imaging machine, etc. A vacuum enclosure surrounds and is spaced apart from a superconductive coil. Apparatus supports the coil in the enclosure during operation of the device, such apparatus including a first thermally insulative honeycomb assemblage positioned between the coil and the enclosure. In a first preferred construction, the first honeycomb assemblage is positioned between and connected to the coil and a thermal shield, and a second honeycomb assemblage is positioned between and connected to the shield and the enclosure. In a second preferred construction, the second honeycomb assemblage is replaced with a first suspension strap.

Abstract: A superconductive magnet having a superconductive coil located within a thermal shield located within a vacuum enclosure. A magnet re-entrant support assembly includes an outer support cylinder located between the vacuum enclosure and the thermal shield and includes an inner support cylinder located between the thermal shield and the superconductive coil. The outer support cylinder's first end is rigidly connected to the vacuum enclosure, and its second end is rigidly connected to the thermal shield. The inner support cylinder's first terminus is rigidly connected to the thermal shield near the outer support cylinder's second end, and its second terminus is located longitudinally between the outer support cylinder's first and second ends and is rigidly connected to the superconductive coil. Buckling resistance is improved by adding stiffening rings to the support cylinders.

Abstract: An open magnetic resonance imaging (MRI) magnet having first and second spaced-apart superconductive coil assemblies each including a toroidal-shaped coil housing containing a superconductive main coil. A generally annular-shaped resistive coil is associated with each coil assembly, being generally coaxially aligned with the associated coil assembly and being spaced radially inward and radially apart from the associated coil assembly's superconductive main coil. The resistive coils overcome the gross magnetic field distortions in the imaging volume of the superconductive main coils (created by the open space between the magnet's superconductive coil assemblies) to produce a magnetic field of high uniformity within the imaging volume.

Abstract: A superconductive magnet with magnetic shielding has an annularly-cylindrical-shaped housing whose first end wall and outer cylindrical wall are magnetizable (e.g., iron) walls and whose inner cylindrical wall is a non-magnetizable wall. At least one main superconductive coil is positioned within the housing and carries an electric current in a first (e.g., clockwise) direction. A first resistive (e.g., copper) deflection coil is positioned outside the housing radially proximate the outer cylindrical wall and longitudinally closer to the first end wall than to a midpoint located between the two end walls. The first deflection coil carries an electric current in an opposite direction to the first direction so that its magnetic field longitudinally pushes the stray magnetic field of the superconductive coil(s), which leaves the magnet's bore, inward to be captured by the iron first end wall.

Abstract: A superconductive magnet with magnetic shielding has an annularly-cylindrical-shaped housing whose first end wall and outer cylindrical wall are magnetizable (e.g., iron) walls and whose inner cylindrical wall is a non-magnetizable wall. At least one main superconductive coil is positioned within the housing and carries an electric current in a first (e.g., clockwise) direction. An annular first permanent magnet is positioned outside the housing longitudinally proximate the first end wall. The first permanent magnet has a number of equivalent ampere turns and has a magnetic field direction oriented parallel to the axis pointing towards the second end wall so that its magnetic field longitudinally pulls the stray magnetic field of the superconductive coil(s), which leaves the magnet's bore, inward to be captured by the iron first end wall.

Abstract: A rotatable subassembly for a horizontal axis clothes washing machine, such subassembly having a rotatable clothes basket and a pair of balance rings. The clothes basket has a generally longitudinally extending and generally horizontally oriented axis of rotation and has two longitudinally spaced-apart ends. Each balance ring has a circumferential interior cavity, is attached to the clothes basket near a corresponding one of the ends of the clothes basket, and has a generally longitudinally extending axis generally coaxially aligned with the axis of rotation. The cavities of the balance rings are in fluid communication with the clothes basket.