GB884349A - Radioactivity measuring apparatus - Google Patents

Abstract

884,349. Rotary conveyers. PACKARD INSTRUMENT CO. Inc. April 8, 1960 [April 10 1959], No. 12657/60. Class 78 (1). [Also in Group XL (b)] Apparatus for measuring the radio-activity of a plurality of samples comprises a storage support to hold the individual samples in an arcuate array ranged round a common centre, at which centre the detector equipment is provided. Transport means are provided to transfer the samples one at a time from the support to the detector for measurement and then back to the support. The detector is mounted in a circular table 35 round which is supported in a rotatable manner on rollers 42 a drum 41 provided with a series of equi-spaced aligned holes in its flanges to support a plurality of samples 10. A motor-driven arm 45 supported above the table carries jaws 48 effective to transfer the samples to and from the detector. Normally, the jaws are urged together by a spring, but at each extremity of travel abutments on the jaws make contact with bearing surfaces and the jaws are opened. With the arm in its outermost position, as shown in Fig. 2 in full lines, energization of the drive motor causes arm 45 to move anticlockwise and, as it starts to move, jaws 48 close and grip the sample 10 positioned beneath them. The jaws are not mounted directly on the arm but are pivoted on a block 45b drawn inwardly by spring 56 and provided with a cam-follower 60. The latter follows cam 61 so shaped that the sample is drawn vertically out of the storage drum and hangs freely as it is then moved across to the centre. Towards the end of the movement the sample is directed vertically downwards into the detector opening and finally released by the jaws. Limit switches control the extent of the movement of arm 45 and a relay circuit (Fig. 6, not shown) is described which enables each sample to be automatically carried to the detector, left for a measuring period, replaced in the storage drum, and the drum then driven round one position for a repetition of the cycle with the next sample.