Abstract: A shutter operating system is provided that depends on electromagnetic energy to operate shutter blades. A permanent magnet and solenoid system operate the shutter blades. Movement of the magnet causes the shutter blades to move between an open and a closed position over a lens. The permanent magnet can be moved between a pair of spaced coils by selectively energizing first one coil then the other. The magnet can be attached directly to a shutter blade or in the case of a rotary shutter, the magnet can be attached to a drive ring that in turn is mechanically coupled to the shutter blades.

Abstract: High flow rate catheters, and related methods, are useful in dialysis and other procedures. A catheter according to the invention comprises a hub and a generally elongated conduit. The conduit has a substantially continuous and smooth wall. The conduit also defines at least one lumen and has a length extending from a proximal end to a distal end of the conduit. The proximal end is coupled to a hub and the distal end has an opening in communication with the lumen. The conduit has a conical shape which tapers along the length.

Abstract: An electromagnetically operable rotary shutter is rendered bi-stable by the use of two linear electric motors, one to open the shutter and a second to close the shutter together with a latch that holds the shutter in either an open or a closed position in the absence of power to purposefully open or close the shutter.

Abstract: A shutter assembly for an optical system includes a shutter housing that maintains optical alignments with adjoining parts of the optical system and a shutter mechanism that can be removed and replaced within the shutter housing without disturbing the optical alignments between the shutter housing and the adjoining parts of the optical system. The shutter mechanism can also include alignment features with the shutter housing for restoring the original optical alignment of the shutter mechanism with the adjoining parts of the optical system.

Abstract: A shutter assembly for an optical system includes a shutter housing that maintains optical alignments with adjoining parts of the optical system and a shutter mechanism that can be removed and replaced within the shutter housing without disturbing the optical alignments between the shutter housing and the adjoining parts of the optical system. The shutter mechanism can also include alignment features with the shutter housing for restoring the original optical alignment of the shutter mechanism with the adjoining parts of the optical system.

Abstract: A shutter operating system is provided that depends on electromagnetic energy to operate shutter blades. A permanent magnet and solenoid system operate the shutter blades. Movement of the magnet causes the shutter blades to move between an open and a closed position over a lens. The permanent magnet can be moved between a pair of spaced coils by selectively energizing first one coil then the other. The magnet can be attached directly to a shutter blade or in the case of a rotary shutter, the magnet can be attached to a drive ring that in turn is mechanically coupled to the shutter blades.

Abstract: An electromagnetically operable rotary shutter is rendered bi-stable by the use of two linear electric motors, one to open the shutter and a second to close the shutter together with a latch that holds the shutter in either an open or a closed position in the absence of power to purposefully open or close the shutter.

Abstract: A damping system for an electromagnetically operable shutter includes a detent for arresting the motion of a pivotally supported shutter actuating drive arm. The detent has damper portions that are fixed to the pivotally supported drive arm and bumper portions that are fixed t positions to receive the impact of the dampers as the arm is pivoted in one direction or another to operate the shutter. The damper portions each has a straight edge and the surface of each bumper portion is curved so as to maintain substantially a point contact between the two throughout the duration of the impact. In addition the damper portions are formed of a damped polyurethane and each bumper portion is formed of an ultra high molecular weight polyethylene, the combination of materials providing energy absorption while avoiding the adherence of damper and bumper portions upon impact.

Abstract: An actuator circuit for an inductive load includes a first low impedence source of direct current at a relatively high voltage, a second low impedance source at a lower voltage, a switching arrangement responsive to an input signal for connecting a load across the first source at the beginning of the signal and for a predetermined initiating interval thereafter, and at the end of the interval switching the load from the first to the second source, and a feedback control for limiting the current through the load to a first, constant value during the initiating interval and to second, lower constant value thereafter. The circuit cuts off the load when the input signal ceases or it removed.

Abstract: A battery operated, portable actuator for an inductive load such as an electromagnetically actuatable photographic shutter includes an initiating capacitor for initiating acutation of the load, and a continuing holding circuit portion for continuing energizing the load after discharge of the initiating capacitor. The capacitor is connected to be charged by the output of a voltage multiplying rectifier which is alternately turned ON and OFF according to the instantaneous voltage across the capacitor, being turned ON when the voltage is low, and OFF when the voltage is high. The continuing circuit portion is arranged to feed time-spaced current pulses to the load, and a diode is connected across the load so that its own inductive nature holds it energized during the intervals between the pulses. The duration of the energizing current pulses is increased in response to fall-off of the battery output voltage.

Abstract: A control circuit for an inductive load comprising a relatively large capacitor, means for charging it through an SCR, and means for discharging it through the inductive load for energizing the load and simultaneously inhibiting the SCR so long as the discharge path for the capacitor remains closed.