Abstract: In a contour collimator for radiation therapy, a variable aperture is formed by two stacks of aperture plates, which are mounted opposite one another. The aperture plates are connected to a setting mechanism in order to alter the aperture created between the opposed aperture plates. All the aperture plates of each stack are arranged on a respective axle. The aperture plates can be rotated individually around the axles and into the aperture.

Abstract: A transmission ion chamber assembly for detecting the lateral displacement of an ionizing beam has two ion chambers located one behind the other along the beam axis. Each chamber contains two electrode plates and a spacer which separates and electrically insulates the electrodes from each other. The electrodes of each chamber are inclined with respect to each other along a preselected measuring axis. The axes of both chambers are perpendicular to the beam axis and to each other. In operation, the collector electrodes furnish current signals which depend upon the position of the beam along the associated measuring axis. With orthogonal chambers, i.e. measuring axes, the beam position in a plane perpendicular to the beam axis can be determined and aligned, e.g. via beam steering coils surrounding the beam.

Abstract: A handle assembly for an x-ray examination apparatus for permitting a technician to position the apparatus above a patient with the aid of a support motor has a grip connected to the apparatus by two support elements, each of the support elements having a defined weak point, such as a segment of reduced thickness, and a plurality of control elements for operating the support motor in response to stresses experienced by the weak point caused by pulling on the grip. The control elements are connected between the support elements and the apparatus, spanning each weak point. Two control elements, disposed at right angles to each other, may be utilized for each weak point.

Abstract: A radiographic installation for an x-ray examination apparatus has two antiscatter grids disposed in different planes at different distances from the focus of the radiation source and are alternately movable by a motor connected thereto through a drive train from a standby position outside of the radiation field into a position within the radiation field. The grids are maintained in the standby position by a permanently-acting bias force and are moved into the radiation field by the motor in opposition to this force. The drive train includes a belt having two cams disposed at the opposite ends thereof respectively associated with the antiscatter grids for limiting the movement thereof to define selected positions for the grids.