Abstract: In a cassette tray for radiography, a positioning plate is provided on a rear surface of a tray, and the positioning plate includes grooves corresponding to cassette sizes. A stopper for holding a cassette has a spring, and engaging pieces which engage the groove and formed at a lower end of a slider moving vertically between a front plate of the tray and the positioning plate. When the engaging pieces of the stopper engage the grooves, the stopper projects from the front surface of the tray to hold the cassette at the position. When the engaging pieces of the stopper do not engage the grooves, the stopper is located on the same plane as the front plate surface of the tray. If the stopper is pressed and moved along the surface of the tray, the position for the cassette to be used can be selected. Accordingly, the cassette tray can securely hold various-sized cassettes, and the attaching operation therefor can be carried out easily in a short period of time.

Abstract: A mobile device for an X-ray apparatus is formed of a freely rotatable hollow column disposed on a mobile base, a holding section for holding an X-ray tube in a vertical direction along the column, and a counter weight connected through a wire to the holding section to be suspended inside the column. A column rotating section formed of a bearing portion and a rotational shaft with a hollow part is disposed in the mobile base. A lower part of the counter weight is provided with a convex portion which enters into the hollow part of the rotational shaft. When the holding section for the X-ray tube is elevated to the highest point, the counter weight is lowered to the lowest point, wherein the convex portion of the counter weight enters into the hollow part of the rotational shaft. Thus, a volume of the hollow part can be utilized as a part of the volume of the counter weight to allow the counter weight to be made of iron and the like, other than lead.