Automatically moved tomographic appts - has control comprising drive mechanism with internal and planetary gears

摘要

A tomographic apparatus in which an X-ray tube and a film travel in straight, circular, elliptical, near-hypocycloidal and spiral paths about a fixed point of an object, keeping a certain positional relationship between them. The X-ray tube and the film are supported by a link mechanism which retains the positional relationship, and the movement is achieved by a control arrangement. The control arrangement comprises a drive mechanism having an internal gear and a planetary gear, in mesh with the internal gear which rotates and moves around the internal gear and a control mechanism for controlling rotation of the internal and planetary gears.