Abstract: Effective centers of rotation of the X-ray beams when projecting the anterior regions are caused to be disposed considerably more interiorly of the dental arch, i.e., farther from the incisors and closer to the X-ray source, to thus provide longer projection radii of the beams at the anterior region. Lengthening of the projection radii is achieved through unique velocity profiles of patient chair movement along an x-axis and film travel within the camera. The longer effective projection radii of beams at the anterior region provide for a substantially wider or thicker layer thereat with a concomitant modest narrowing of the layer at the canine regions.

Abstract: A film drive mechanism is disclosed for use with a radiographic apparatus which provides continuous radiographs or x-rays of a selected portion of a subject lying in a horizontal position by simultaneously rotating an x-ray source and an x-ray film holder including an x-ray film about the subject. An x-ray film cassette is mounted in the film holder and while the film holder rotates about the subject, the film cassette is moved past an x-ray slit. The film holder includes a novel drive mechanism for moving the cylindrical film cassette, in which an x-ray film is placed, at the proper rate of speed to provide the desired x-ray during rotation of the source and film holder. This is accomplished by utilizing a sloped cam having a configuration determined by the desired focal trough to vary the relative rotation of the shaft of a motor driving the film and the housing of the motor.

Abstract: A conveyor apparatus, such as a cart, is disclosed, for aiding in the placement of subjects to be x-rayed in position in a radiographic apparatus. The conveyor apparatus includes a conveyor belt on which a patient is placed and a mechanical linkage having a mechanical advantage connecting the conveyor belt to an operator, so that relatively small movement of the operator causes relatively large movement of the patient carrying conveyor belt.