GB706378A - Improvements in x-ray apparatus - Google Patents

Abstract

706,378. X-ray apparatus. ELECTRONIC & X-RAY APPLICATIONS, Ltd., TUNNICLIFFE. E. A. J., and WAY, R. F. May 12, 1952, No. 12048/52. Class 98(1) In a shutter for X-ray apparatus, the movable plates are coupled to a continuously operable driving component through a resilent slipping drive device, the resilient component of which is loaded by drive reaction set up by movement of the plates to their closed position or their arrival at that closed position and which acts to hold the plates in that position when drive ceases. As shown in Fig. 1, shutter plates 1, la, are slidable'in guides 3, 4 over an X-ray transparent window 24 in the bottom of a tray 23, and are connected to pivoted levers 7, 8 so as to move equally in opposite directions. Lever 8 is bolted to a pinion 10. An electric motor 17, Fig. 4, drives a shaft 15 through gearing 16. A worm 14 rotatably mounted on shaft 15 is held between friction discs 18, 19 urged towards each other by springs 20, 21. When the shutter plates are being closed, worm 14 drives a pinion 13 fast with a pinion 12 driving pinion 10. When the plates abut, worm 14 moves along shaft 15, compressing one of the springs, until the friction discs 18, 19 slip. When the motor is switched off the spring action on worm 14 presses the plates together. Similar action takes place when the plates have been separated as far as they will go by reversing motor 17. A second similar pair of plates and driving means is mounted in a tray similar to 23, and the trays are mounted with their open ends together and with the directions of movement of the two pairs of plates at right-angles. The driving motors are operated by separate switches. Alternatively, both pairs of plates may be driven by a single motor. The shutter assembly may be mounted, together with an X-ray tube and a fluorescent screen, on a movable carriage in an X-ray apparatus.