| 摘要 |
PURPOSE:To enlarge the downwardly movable area of an X-ray tube which is supported by parallelogrammatically disposed arms by pulling a spring, adapted to pull said arms through a spring hook lever and providing a stopper for limiting the movement of said lever. CONSTITUTION:An X-ray tube support 4 and a vertically movable slider 2 are linked by a pair of mutually parallel arms 8, 9 whose both ends are supported by their respective pivot pins. A pulling spring 10 is coupled with a spring hook 12 rotatably connected with a spring lever 11 which is swingably supported on a supporting plate by a pin. And, a stopper 13 is provided below the spring hook lever 11. Accordingly, when the arms 8, 9 swing downwardly from their horizontal positions, the stopper 13 prevents the turning movement of the lever 11 and strengthens the pulling force without need for stretching the spring further, therby enlarging the downwardly movable area of the X-ray tube. |
