GB1465678A - Automatic sampliing mechanisms - Google Patents

Abstract

1465678 Sampling apparatus for liquids SOCIAL SERVICES SECRETARY OF STATE FOR 1 May 1974 [17 April 1973] 18412/73 Heading B8N [Also in Division G1] An automatic sampling mechanism in which liquid in discrete quantities is introduced through a tube 26 into a receiver 14 or 14A, has a beam 30 pivoted to one end of a lever 40 and arranged when the lever pivots to engage an adjustable stop 62 and so bring the end portion of the tube into sidewise contact with an interior wall of a receiver for the period during which, in use, liquid is introduced therein, so that when the tube is withdrawn from the receiver substantially no droplet of liquid is on the outside of the tube. As described a ring of receivers, e.g. 14, 14A, is formed in a disc 16 surrounded by an annulus 12 containing vessels 10, 10A, and holes 24, 24A. The disc 16 and annulus 12 are mounted on a table 18 which is intermittently driven from a continuously driven shaft 56. The tube 26 and a further tube 28 are connected via tubes 32, 34 respectively to a dispensing/diluting device 36, and are carried at one end of the beam 30 pivoted at 38 to the lever 40 and spring urged clockwise to a position normal thereto. The lever 40 is pivoted to a rotatable column 46 and at its free end has a follower 52 engaged with both the face and edge of a cam 54 on the shaft 56. In operation, from a starting position in which the beam is in the positions 60, Fig. 2, and 30, Fig. 1, and the lever is in the position 40, rotation of the cam 54 causes the lever to pivot to position 40A thus lowering the beam and inserting the tube 26 into a vessel 10 and the tube 28 through a hole 24. A switch 74 then causes the device 36 to operate so that a sample of liquid is sucked from vessel 10 into tube 26. Further rotation of the cam raises beam 30, pivots it to position 60A, Fig. 2, and then again lowers it. During lowering of the tube-carrying end of the beam its free end 76 engages the adjustable stop 62 so that the tube end follows the path 78 and engages the sidewall of a receiver 14 as it enters therein. Tube 28 also contacts the side wall, the ends of the tubes 26, 28 being flexible to cater for this. Device 36 is then operated to discharge the liquid sample from the tube 26 into receiver 14 and also to supply a reagent via tube 28. The tubes are then raised and returned to their starting positions and the table 18 is indexed for a further cycle of operation. From the starting position the beam 30 may be swung to the position 60B to facilitate access to the table 18. Such swinging is effected by a handwheel 86, operation of which is prevented by interengaging locking means on the camshaft 56 and table shaft 20 when the beam is not in the starting position.