GB1308041A - Mobile dispenser for radioactive sources - Google Patents

Abstract

1308041 Shielded containers NATIONAL RESEARCH DEVELOPMENT CORP 26 Feb 1970 [26 Nov 1968] 56109/68 Heading B4Q [Also in Division A5] A mobile dispenser for sources of radio active caesium for use in hospitals in the treatment of tumours of the uterus comprises a lead chamber 11, 12 containing a magazine 13 mounted on a trolley (not shown). The magazine has three series of holes arranged as concentric circles 14, 15, 16, each circle having the same number of holes, viz. twenty, and the holes of the circles being in radial alignment. Each hole contains a radio active source. the sources being of three different strengths accommodated, respectively in the three series of holes. The chambers 11, 12 has three series of holes 19, 20, 21 corresponding to the magazine holes whereby a flexible nylon probe 23 wound on a wheel 24 having a handle 24a may be advanced from left to right through the chamber to eject a selected source and deposit it in an applicator 30. The magazine 13 is mounted on a shaft 17 rotatable by a selector wheel 18 which selects a particular hole in the circles 14, 15, 16. The particular circle 14, 15 or 16 is selected by mounting the probe wheel 24 on an arm 22 extending from a shaft 37 rotatably mounted in the trolley. A further arm 36 on the shaft supports a block 32 in which is mounted a holder 31 carrying the applicator 30. A hand wheel-operable slideway 33 on the arm 36 is adjustable with reference to a scale 34 and enables a selected channel 29 in the applicator 30 to be aligned with the probe 23. The arm 36 may be raised or lowered into four different positions by a cam 35 to rotate the shaft 37 whereby in three of these positions the probe 23 is aligned with a selected one of the circles 14, 15, 16 and in the fourth position a gate 39 mounted on the shaft closes all the magazine exits. Each circle of holes 14, 15, 16 has a corresponding counter wheel 26, 27, 28 secured to the shaft 17, the periphery of each wheel having numbers one to twenty thereon, one of these numbers appearing through an aperture 45 provided in the periphery of a cover 44 surrounding the associated wheel. Initially, the numbers twenty would show through each aperture 45 but as a source is used, the corresponding cover 44 is rotated one step relatively to the counter wheel whereby the number showing through the aperture is reduced by one. The construction of the covers 44 and the cam mechanism whereby the appropriate cover is stepped by the probe 23 is described with reference to Figs. 4a-4b, not shown. Return of a source to the chamber 11, 12 causes resetting of the respective counter to its previous position through motion transmitted through a cable 54a. The applicator 30 serves as a vaginal box, an alternative applicator 30a in a holder 31a serving as a uterine tube.