Patent GB-233837-A (GB)
Title: Improvements in and relating to operating tables for x-ray treatment
IPC: A61B6/04
Filed: 1924-03-28
Abstract: 233,837. Pohl, E. March 28, 1924. R÷ntgen-ray apparatus comprises a table or the like for the patient, which is rotatable about a longitudinal axis in a support which is tiltable about a transverse axis, the table being situated so that the longitudinal and transverse axes of rotation pass substantially through the centre of gravity of the patient on the table, the tablesupporting means allowing free access to the patient on at least one side in all positions. In one form, Figs. 1 and 3, the table 14 is carried by a frame 4 formed of two curved members 4<a> movable transversely between rollers 2, 82 mounted on a fixed base 1. The frame 4 is tilted by means of a rack 5 attached thereto and engaged by a worm 7 driven by an electric motor 9. The table 14 is attached to angle-members 12, 13 carried by pins 10, 11 journaled in bearings 4b, 4d attached to the frame 4, and has adjustable head and foot rests at 16, 15 and a piece of girthing 17 with straps 18 for securing the patient to the table. To rotate the table about its longitudinal axis a curved member 19 attached thereto carries a rack 20 which is engaged by a worm 21, Fig. 6, carried by the frame 4 and rotated by a crank 23. The holder for the R÷ntgen-tube 40 and the plate or screen 42 consists of an arm 38 pivoted to a slide 36 moving on a guide 26 which is pivoted at one end 25 to one arm of a lever 24 freely pivoting on pin 10, and at its other end to a ring 28 encircling the table 14 and rotatably mounted between rollers 29, 31 on the frame 4. The opposite side of the ring 28 has a counterbalance-weight 33 and a handle 132 to enable the guide 26 to be turned manually. The ring 28 is provided with a hinged portion which can be opened to allow the patient to get on the table 14. The tube and plate holder are longitudinally displaced on the guide 26 with respect to the table 14 by means of a screw 48 engaging with the slide 36 and rotated through belt 45, pulley 43, and gear-wheels 46, 47 from an electric motor 34, mounted as a counter-balance on the free end of the lever 24, and controlled by a switch 51. Handles 53, 54 control through lever mechanism the opening of the diaphragm, which consists of two crossing pairs of parallel sliding plates. The holder 42 for the plate or screen is carried by a sliding bracket 41<a> secured on the arm 38 by a lock-nut 41<b>. Movement of the tube and screen with respect to the patient is controlled by an arm 65<a>, Fig. 3, to which is pivoted at 81 a link 79 also pivoted at 80 to the guide 26. The arm 65<a> is secured to a ring 65, Fig. 9, loosely mounted, co-axial with the pin 10, on a bush 64 secured to the arm 4<b>. The points 10, 25, 80, 81 form the corners of a parallelogram so that, when the arm 65<a> is allowed to move with the lever 24 when the latter is swung round, the arm 38, with tube 40, will, owing to frictional resistance of the pin 25, retain its angular position throughout with reference to lever 24. If, however, a non-rotatable ring 66 is pressed, by actuation of a lever 68 secured thereto, into contact with ring 65, the latter is prevented from rotation and holds the arm 65<a> rigid, thus causing the guide 26 to occupy parallel positions only, on rotation of arm 24. The lever 68 is actuated from a lever 78 on the frame 4 through a pullmember 75, passing through a tube 76 and rods 73, 71. To use the R÷ntgen-ray devices with a patient not on the table, the arm 24 in one example is swung through 180‹ from the position shown in Fig. 1, and the guide 26 swung out on the pins 25, 25<1> so that the patient can stand between the tube and screen. In another form, Fig. 15, the frame 84 is a complete circle and carries the pins 10, 11 on which the table 14 is mounted, the supporting arms 24, 24<1> for the guide 26 being mounted on the pins 10, 11. Counter-poises 86, 86<1> are provided on the backward extensions of these arms. The table is tilted by hand and is locked in position by a spring-controlled pin 88 engaging with a member 89, Fig. 15<a>, on arm 24<1> having circularly arranged apertures 90. The pin 88 is operated by a lever 92. The ring 84 rests on rollers 96, 97, 96<1>, 97<1> carried by arms 98, 99, 98<1>, 99<1> pivoted in pairs on pins 100, 100' mounted on a bedplate 102. The pairs of arms are adjustably connected by pivotally mounted screw-members 103, 103' actuated by handles 107, 107', so that the angle between the pairs of arms can be varied to vary the height of the ring 84 and table 14. The roller 97 has a toothed wheel engaging a rack 85 on the ring 84 and rotated by a crank 112 to rotate the ring and tilt the table. The tube and screen holder 38 is slid along the guide 26 by a handoperated cord 115 having a counter-poise 117. Two parallel similar rings 84 may be used, or a single ring which is laterally supported as by rollers 128 to prevent it tilting over. In a further form, Fig. 16, an elliptical ring 118 is used and the table is replaced by a hammock 119 which can be turned simultaneously at both ends by the engagement with toothed wheels 127, 127', to which the ends of the hammock are secured, of racks 126<b>, 126<c> operated by a lever 121 which can be locked in adjusted position. In a further form, Fig. 17, the ring 84 is mounted on a form 129 mounted on a pin 130 in a bearing 131 in a pedestal 135 or a solid wall. When the fork 129 is sufficiently strong the ring 84 may be dispensed with.