GB707202A - Tube support for x-ray irradiation apparatus - Google Patents

Abstract

707,202. X-ray apparatus. LlCENCIA TALALMANYOKAT ERTEKESITO VALLALAT. Aug. 22, 1952 [Sept. 4, 1951], No. 21195/52. Class 98(1) [Also in Group VI] A tube support for X-ray irradiation apparatus comprising a tube holder and means for moving the tube holder around two axes, one of which is stationary and the other movable, which intersect each other at right-angles so as to direct the centre line of the tube holder constantly towards the point of intersection of the axes, is characterized by a primary guide determining a circular path around one of the axes, and by a secondary guide carrying the tube holder and adapted to move along the circular path, means being provided for oscillating the tube holder along the secondary guide with respect to the other axis. As shown in Fig. 9, a shaft driven by a motor 36 and journaled in a bracket 35 carries an arm 33 supporting a guide 23. An X-ray tube 18 is movable on the guide by means of a motor 31 mounted on the tube housing and driving a pinion engaging rack teeth on guide 23. The guide is so shaped that the X-ray tube moves in an arcuate path about an axis intersecting the axis of rotation of arm 33 at right-angles. The patient lies on a table 40 which is so adjusted that the region 16 to be treated lies at the intersection of the axes, towards which the X-ray beam is always directed. In use, arm 33 is rotated while the tube 18 moves to and fro on guide 23. Motor 31 may be reversed at each end of its travel by press-button switches 47, Fig. 10, on the tube housing, which engage abutments 48 fixed at each end of guide 23. Strips 51 may also be fixed to each end of guide 23. A lead strip 54 may be mounted on each of two strips 51 mounted at the ends of guide 23 to penetrate into the ray-defining cone at each end of its travel to cut off the X-ray beam. The number of movements of the tube on guide 23 during each revolution of arm 33 can be varied, and it is shown that when this number is small the region of maximum irradiation is well defined, and when the number is large the dosage falls off slowly with the distance from the region of maximum irradiation. To vary the distance of the tube from the area 16, arm 33 may be adjustable in length, and a number of interchangeable arms 23 of different curvature may be provided. The travel of the tube on arm 23 may be varied by attaching additional blocks to abutments 48, the strips 54 being also adjustable towards and away from strips 51. In an alternative construction, Fig. 13, the guide 23 is fixed at right angles to a rotatable ring 58 having teeth 59 engaging a pinion 60 driven by motor 36, the region 16 to be treated being at the centre of the ring. In either construction the guide 23 may be straight, and the tube mounted to tilt as it moves along the guide. The motors may be energized by electric cable, or replaced by a single motor with flexible cable drives to the parts of the apparatus, which may in this case be driven through variable speed gearing.