| 摘要 |
1,206,767. Radio-active source container. D. LECUYER. 8 Dec., 1967 [20 Dec., 1966], No. 56044/67. Heading H5R. In a source container, a shielded position and exposure position are available for the source with a conduit allowing movement between the two, the arrangement being such that on withdrawing the source into the shielded position, the conduit is automatically blocked and the presence of the whole of the source in the shielded position is verified there being means for producing an alarm signal if the returned source is not of the correct size. The blocking or obturating member 8 is preferably slidable along the conduit away from the source when it is being exposed, being then displaceable laterally to exposure the source, this lateral movement being linear (Fig. 12, not shown) or a rotation e.g. about axis 9 (Fig. 3), the obturator being supported in a suitable carrier. Preferably the obturator 8 is received into one tube 10 of two tubes 10, and 11 supported by a cradle 9 pivoting about axis 9a, the tube 11 being adapted to receive the source during exposure. The pivotal movement of the cradle 9 and the translatory movement of the obturator 8 may be accomplished using a rotary cam 13 having a slot 18 in which a stub 19 attached to the cradle operates, the cam also having a pin 14 which co-operates with slot 15 in lever 16 to accomplish the translatory movement of obturator 8. In Fig. 2 and Fig. 3 the exposed position is shown in full line the shielded position in chain dotted line. It is preferred that the arrangement be such that the cradle 9 cannot be rotated from the exposed position until the source has been withdrawn from it. In returning to the shielded position the obturator 8 is arranged to contact the source, and the end of the lever 16 occupies a certain position according to the length of the source. Any deviation from the normal position may be adapted to activate an alarm system, and if desired the normal position may activate one type of signal, the abnormal a second signal (Fig. 7, not shown). The cam 13 is operated by a ratchet 22 and sprocket 21 which turn axle 20 (shown in section in Fig. 3). The cam 13 may be held in the exposed position against a spring loading of ratchet 22 by a spring loaded pawl 31 which operates via lever 33 against a stop (not shown). The movement of the cradle and the replacement of the obturator may be made to be automatically dependent on the return of the source by ensuring such return releases the stop. |
