Abstract: A magnetic resonance imaging scanner includes a generally cylindrical main magnet assembly (10) that defines a cylinder axis (16). A first set of shims (60) are rigidly positioned inside the magnet assembly (10) at about a first distance (d1) relative to the cylinder axis (16). A second set of shims (62) are rigidly positioned inside the main magnet assembly (10) at about a second distance (d2) relative to the cylinder axis (16). The second distance (d2) is different from the first distance (d1). A generally cylindrical radio frequency coil (26) is arranged inside the main magnet assembly (10) at about a third distance (d3) relative to the cylinder axis (16). A plurality of gradient coils (20) are arranged inside the main magnet assembly (10) at about a fourth distance (d4) relative to the cylinder axis (16).

Abstract: A diagnostic imaging apparatus such as a magnetic resonance imaging (MRI) device includes a vacuum vessel (24) having a central helium reservoir (16) in which superconducting magnetic coil windings (10) are maintained at a superconducting temperature. The vacuum vessel defines a bore (12) within which a gradient tube assembly (30) and an RF coil (32) are received. The gradient tube assembly includes an integral tongue (66) extending from a patient end (48) thereof. A first constraint (70) retrains the gradient tube assembly in a “push-pull” arrangement in both directions along the z-axis. The constraint (70) is mounted to a patient-end of the vessel (24) at a lowermost (i.e., six o'clock) position. The constraint includes vibration isolators (94) interposed between the tongue and a saddle mount (72) to reduce vibration transmission from the gradient tube assembly to the vessel.

Abstract: The magnetic field assembly of a magnetic resonance imaging device includes an annular superconducting magnet (10) which is mounted within a toroidal vacuum vessel (24). Two cylindrical members (26, 46) define an annular gap (58). A shim set (60) for shimming the uniformity of the magnetic field is mounted in the gap (58). The shim set includes a plurality of shim trays (62), each of which defines a plurality of shim receiving pockets (64). A bottom wall (81) of each pocket is spaced from the cylindrical member (26) by side walls (76) and feet (78) to minimized heat flow. Shim tray covers (68) have flanges (90) and narrow contact surfaces (94) which are cammed against surfaces (61) of spacers (56) to press the cover on the tray and the tray feet against the cylinder (26) while minimizing heat flow through the spacers to the shims.

Abstract: A magnetic actuator for adjusting the zero and span settings of a transmitter used in industrial process control systems. The actuator has a single magnet in a housing. The actuator is removable from the transmitter.When the actuator is unactuated the magnet is in a null position wherein it does not actuate either the zero or span setting reed switches. The magnet can be moved to either a first position wherein it actuates the zero setting reed switch or a second position wherein it actuates the span setting reed switch. The actuator applies a torque in the proper direction to return the magnet to the null position when the torque applied to move the magnet to either the first or second position is removed.

Abstract: A cover lock assembly for a process transmitter having threadably removable end caps and corrugated outer surfaces is provided for engaging the corrugated surfaces by way of a toothed cover lock which is removably affixed to the transmitter housing.

Abstract: An apparatus in which an auger, coupled to a hopper storing toner particles, dispenses toner particles substantially uniformly into a developer mixture. The auger comprises a tubular member having a plurality of apertures therein for discharging toner particles therefrom. A toner transport is disposed interiorly of the tubular member for advancing the toner particles therealong. The toner transport has a helical tooth for advancing the toner particles along the tubular member. The helical tooth has sections thereof deleted therefrom in the region of the apertures in the tubular member to facilitate discharging of the toner particles from the toner member and to prevent caking and clogging thereof.