Patent GB-562303-A (GB)
Abstract: 562,303. Rontgen - ray apparatus. GOLDFIELD, E. R., SCHIRING, R. C., and STAVA, R. J. March 9, 1942, No. 3068. [Class 98 (i)] An X-ray apparatus with means for localizing embedded foreign bodies comprises a carriage supporting electrical equipment, a carrier bracket for an X-ray tube mounted on the carriage, means for supporting on the carriage an X-ray screen in opposition to the tube and means for indicating the length of travel of the carriage necessary to move the image of the foreign body by a predetermined amount on the screen. The apparatus shown forms a mobile unit which may be readily disassembled and packed for transport. It comprises a base carriage 25 supported by wheels 27 and castors 26. The castors may be prevented from swivelling by bolts when the movement of the carriage is to be confined to a straight line, and the carriage may be immobilized by brakes which lock the wheels 27. A well in the carriage receives the lower end of a transformer case 33, in the top of which is a well to receive the reduced end 36a of a control panel unit 36, as shown in Fig. 6, in which parts of the apparatus are shown disassembled. Toggle-jointed tie-rods 41 secure the units 36 and 33 to the carriage. The carriage also supports a mast comprising a pair of parallel tubes formed in sections 53, 55, 56, 57 connected by spigot and socket joints and held together by a hinged bolt (not shown) extending centrally through each tube and screwed into a socket 62 in the base, Fig. 11. The mast is rotatably supported in a well casting 51, secured to the carriage, by means of a central lower bearing 67, upper annular vertical bearing surfaces 51a, 59a respectively on the well and a disc carried by the mast and by a roller 63 on the mast engaging a track on the upper edge of the well, the track being formed with four depressions spaced at 90 degrees into which the roller sinks to locate the mast in four positions in which a cross-arm 47 carried by it is either parallel or perpendicular to the long side of the carriage 25. The arm 47 consists of a parallel pair of tubes mounted on rollers in a carriage 46, Fig. 6, so as to be horizontally adjustable. The carriage 46 is adjustable vertically on the mast. by a gear engaging a rack 60 and is automatically locked in adjusted position. C-form bracket 48 is carried on the arm 47 by a detachable spigot and socket connection, so that it may be angularly adjusted about a horizontal axis. One limb of the bracket carries an X-ray tube 50 by a similar connection, so that the tube may be directly mounted on the arm 47 after removing the bracket. A bracket 88 carrying a fluoroscopic screen is secured by a detachable spigot and socket joint 89 to an arm 94 pivoted to the bracket 48. For horizontal fluoroscopy the screen is counterbalanced by engaging a spring-retracted yoke 93 over the hooked end of the arm 94. Two pairs of diaphragm shutters, each consisting respectively of two blades 101, 103 adjustable 'towards and from each other, are operated through linkwork connections, rods 102, 104, levers 119 and links 120, from a pair of levers 121. When localizing foreign bodies, the carriage 25 is mounted on a track formed of sections having along one edge a flange track 127 and a rack 128 engaged by a gear 144 mounted on a vertical operating shaft formed of clutch-connected sections 142, 150. The subject containing the embedded body is immovably supported between the X-ray tube and the screen, and the carriage 25 carrying with it the tube and screen is then moved by rotation of the shaft 150 through a distance sufficient to cause the image of the foreign body to pass from one to the other of a pair of cross-lines on the screen. The necessary movement of the carriage depends on the distance of the body from the screen, so that the latter may be indicated by a suitably-calibrated dial 153 on the shaft 150. The distance from the upper surface of the subject to the screen is determined by means of a skin pad 157 carried by an arm mounted on a vertical plunger operated by a knob 162. When the pad is in contact with the subject the required distance is indicated by a dial rotated by the vertical plunger through a rack and pinion. To cause the dial 153 to indicate the distance of the foreign body from the surface of the subject, which distance is equal to the difference of the distances of the foreign body and of the surface of the subject from the screen, the dial may be given an initial negative setting on the shaft 150 corresponding to the reading of the skin pad dial. The cables 40 between the transformer and X-ray tubes pass over supports 123 carried by a slide which is vertically adjustable on the mast and held by a spring catch which engages the rack 60 and is automatically released when engaged by a portion of the carriage 46 when the latter is being raised on the mast.