Abstract: An X-ray table having an elevator mounted on a base for vertical movement, an intermediate support mounted on the elevator for moving longitudinally, and a carriage with a patient cradle on it for moving longitudinally on the support. A pair of gas springs mounted at the forward end of the table provides a constant upward force to compensate for weight of the elevator and the cantilevered load which is exerted as the patient cradle is extended in the longitudinal direction. There are individual servomotors for driving the support and the cradle. The intermediate support drive includes a drive bar and switch assemblies for sensing any force of more than 25 lbs., for example, exerted on the patient or patient cradle and for disengaging the servodrives in response thereto. The cradle drive incorporates a zero-backlash longitudinal friction drive which includes a harmonic drive unit to achieve accurate positioning of the patient.

Abstract: Curved X-ray filter elements are arranged circularly around a drum. Alternate circumferentially adjacent elements have different filtration properties. Diametrically opposite elements have the same properties. An X-ray source provides a sequence of alternate low and high energy X-ray beam pulses. A multicell X-ray detector produces X-ray attenuation data for each pulse and the data is switched to alternate memories. A drum drive motor is energized at power line frequency. A pinion on the motor shaft turns a gear. A lug that is mounted for angular adjustment on the gear drives the drum. A multiple blade shutter is also mounted on the gear for angular adjustment and rotation with the gear. The shutter alternately interrupts and restores a light beam to a photosensitive device which produces corresponding signal state changes or trigger signals. The signals are used to synchronize the low and high energy X-ray pulses, the filter element angular locations and memory switching with power line frequency.

Abstract: A cable retractor for a computed tomography scanner that is driven with a motor and a belt through two revolutions between clockwise and counterclockwise limits about a horizontal axis. An inner drum is fixed on the scanner for rotation therewith and a stationary outer drum is concentric to the inner drum. Cables are fastened where they enter the outer drum and exit the inner drum on their way to the scanner. A loop is formed in the cable in the circular channel defined by the concentric drums to provide enough cable length for the scanner to make two revolutions. A disk facing the channel is journalled for rotation on the inner drum. Pulleys extend axially from the disk to support the cable loop. The disk is belt driven so its angular motion is a constant fraction of the motion of the scanner whereby the pulleys move at the same rate as the loop to keep it supported as cable is reeled between the drums.

Abstract: A collimator assembly for defining an aperture for the passage of a diagnostic x-ray beam in an x-ray diagnostic apparatus which may, for example, be used in computer assisted tomography. The collimator assembly comprises a framework adapted to be secured to the x-ray apparatus contiguous the x-ray tube, and includes a first and a second blade subassembly lying in a common plane with each other in the path of x-rays emanating from the x-ray tube. Leaf spring means connect each of the blade subassemblies to the framework, the leaf spring means biasing the first and second blade subassemblies into abutting relation to each other whereby to define a zero aperture condition for the passage of a diagnostic x-ray beam through said collimator assembly to the patient.