| 摘要 |
800,663. X-ray apparatus. PHILIPS "ELECTRICAL INDUSTRIES, Ltd. Oct. 11, 1955 [Oct. 14, 1954], No. 28926/55. Class 98(1) [Also in Group XXXVII] In irradiation apparatus, the source of radiation performs, during treatment, a movement over a surface, and the speed of the radiation source is adjusted to the duration of the irradiation so that the time required by the source to cover the prescribed path is equal to the irradiation period, and an electric device, which controls the speed of the driving gear for the radiation source, is controlled by a voltage derived from a measuring resistor, this resistor being included in the current circuit which varies with the irradiation period and with the path to be covered by the source during treatment. As shown, the armature 6 of an electric motor drives a pinion 5 engaging a rack 4 fixed to a slidable rod 3 carrying an X-ray tube 1, which is oriented by means not shown so that its principal ray is always directed to a point M. Switches 13, 14 are mounted on insulated riders 11, 12 slidable on a fixed rod 10. The switches co-operate with a lug 15 on the rod 3 to switch off the motor at the end of the travel of the tube 1, in known manner. The time switch for the X-ray tube has a pointer 17, which is adjusted to vary the time of energization of the tube, and which is connected to a movable contact 18 of a potentiometer 19. An auxiliary voltage developed across contacts 23; 24 is applied to potentiometer 19 and a fixed resistance 19a, which are connected to a second potentiometer 20 with sliding contacts 21, 22 carried respectively by riders 11, 12. Contacts 21, 22 are connected to a resistance 25, across which is developed a voltage Vst which is therefore a function both the energization time (through action of potentiometer 19) and the angle # swept by the line passing through M representing the principal ray. The voltage Vst is applied to a control device 26, comprising e.g. thermionic valve circuits or transductor circuits, so that the current supplied from a source connected to terminals 27, 28 to the motor armature 6, and the field winding 7 also if required, is varied in accordance with the applied voltage Vst, the speed of the motor and hence of the tube 1 being consequently controlled. |
