GB632914A - Improvements in and relating to x-ray apparatus - Google Patents

Abstract

632,914. Rontgen-ray apparatus. PHILIPS LAMPS, Ltd., and NEMET, A. A. Dec. 13, 1943, No. 20871. [Class 98 (i)] Radiographic apparatus in which it is required to use the ray-tube in one or other of two positions at different distances from the fluorescent screen or cassette comprises a raytube holder on a support constrained as by a parallel-motion linkage to move from one position to the other in such wise that the axis of the X-ray beam is directed towards the centre of the screen or cassette in both positions. The effective area of the beam at the screen or cassette may be limited automatically to the area of the screen or cassette by diaphragm means coupled to the movable ray-tube support as described in Specification 632,915. As shown, the ray-tube 32 (Fig. 2, not shown) is disposed vertically in a holder 5, Fig. 1, carried by a frame 4 connected by parallel horizontal spindles 6, 11 to equal parallel arms 7, 10 mounted on parallel horizontal spindles 8, 12 turning in fixed bearings on the transformer unit 2, the arrangement providing a parallelmotion linkage whereby the tube holder 5 may be swung from the position of use shown to the second position of use in which the parallel arms 7, 10 are oppositely inclined to the vertical, while maintaining the ray-tube vertical. Lugs 16 on the arm 7 are pivoted to the pistons 17 of buffer-spring devices 23, turning on fixed pivots 20, which serve the twofold purpose of cushioning the weight of the moving system throughout its movement in either direction, and of arresting the system in its two positions of use, the latter purpose being effected by spring-biassed latch means 28 on one or more of the plunger guides 18 adapted to enter one or other of spaced locking notches on the plunger 17. The tube holder 5 also carries a spot-light projector with its axis parallel to that of the X-ray beam, whereby the centring of the latter in the two positions of the ray-tube may be checked. A cover 3 (Fig. 2, not shown) encloses the transformer unit and buffering arrangement.