Patent GB-250977-A (GB)
Title: Rontgen apparatus
IPC: H05G1/58
Filed: 1926-04-19
Abstract: 250,977. Electricitõtsges. Sanitas (Assignees of Feissly, R.). April 18, 1925, [Convention date]. R÷ntgen-ray apparatus which may be used both for diagnosis and for photographic exposures is controlled by switch means operated by a single lever, the operation of which causes the parts of the apparatus to be arranged either for a diagnosis or an exposure. The apparatus is also provided with a time-controlled device working in conjunction with the switch for throwing the means for making the exposure into and out of operation, and for controlling the duration of exposure. The apparatus comprises a rotary drum 6 which has wipers I - - VI, working in conjunction with stationary contacts I<1> - - VI<1>, and carries on its shaft an operating lever working over a set of four stationary buttons upon any one of which the lever is held by a spring locking device on the drum shaft. The various contacts are coupled up in the manner shown in Fig. 6 to the parts of the apparatus, which include resistances R1, R2 in the circuit of a transformer T1 for heating the cathode of the ray-tube, a resistance R3 for regulating the voltage supplied from the alternating mains to the transformer T2 which energizes the tube, an auto-transformer R, interrupters J, j3 and a device 5 for timing the operations involved in the photographic exposure. The device 5 comprises a clockwork mechanism having two pointers 13, 14, Fig. 4, which may be set to any positions over a scale 12; and on release of the mechanism the pointer 13 first moves until it reaches the pointer 14, and then carries this with it back to the zero setting. The ray-tube is mounted together with a photographic plate in a box 21, Fig. 5, which is surrounded by a lead jacket, and is slidable in a framework 22 in a frame 24. It is displaceable by means of a cord 25 into the position shown and is locked in this position for diagnostic work by a catch 20 controlled by an electromagnet 19; on release of this catch the tube-box descends under its own weight in front of a fluorescent screen 23 ready for the photographic exposure. Preliminary settings of the drum are first made to determine the intensity of the heating current required for exposure and diagnosis. To make a diagnosis, the drum is turned so that the contacts II - - II' and III - - III' are closed. In this setting, the cathode is energized through the resistances R1, R2, and the tube is energized through the resistance R3 for a diagnosis on the fluorescent screen 23, which is slidably mounted, together with the frame 22, in the frame 24. To make an exposure, the drum 6 is turned into a position in which contacts IV - - IV<1>, V - - V<1>, and VI - - VI<1> are closed. In this position (a) the cathode of the tube is energized through the resistance R2 only : (b) the electromagnet 19 is energized and releases the catch 20 so that the ray-tube box 21 descends into position in front of the screen 23; (c) the electromagnet 26 is energized and releases the timing-device 5, the pointer 14 of which has been previously set for the duration of the exposure and the pointer 13 of which has been advanced beyond the pointer 14 through an angle sufficient to permit the necessary re-arrangement of the apparatus prior to exposure to be completed : (d) the pointer 13 moves towards zero position and, when it reaches the pointer 14, closes a contact 18 completing the circuit of the relay J1, which closes the interrupters J, j<3> and thereby short-circuits the resistance R3, so that the transformer T2 receives the voltages necessary to energize the tube for the exposure : (e) the pointer 13 carries the pointer 14 with it to the zero position; during this movement the exposure is made, and when the pointers reach the zero position j<3> the circuit of the relay J1 is broken, and the interrupter contacts J are broken, so that the exposure is terminated. The whole apparatus is mounted in a casing supported by a table, the lever controlling the drum 6, and the timing-device 5, being accessibly mounted on the top of the casing.