GB1399610A - Automatic sampling and dispensing apparatus - Google Patents

Abstract

1399610 Automatic analysis MICROMEDIC SYSTEMS Inc 9 June 1972 [11 June 1971] 27032/72 Heading G1B Apparatus for processing racks, Fig. 1, each having in use a row of sample-containing tubes T1 and an adjacent row of tubes T2 which may contain reagent, comprises a base 2 having a supporting surface 4 divided into a rack-loading area (as shown, behind retractable guide arm 12), a rack advancement area and a rack ejection area, a device which may include teeth 51 to advance a rack along a linear path from an initial position adjacent the rack loading area to a final position adjacent the ejection area, a liquid sampling device which includes an aspirating and dispensing tip device in communication with conduit means and housed above the linear path (at 28), a tip-moving device comprising means for shifting the tip to and fro between two positions, one over a tube T1 and one over the corresponding tube T2, and means for raising and lowering the tip in a straight line at each of the two positions, rack-ejection means 54, 55 adjacent the final position for ejecting a processed rack from the path in a direction transverse to the path, means for feeding racks in the loading area successively into the initial position of the path by moving racks in a direction opposite to that of ejection, and control means for co-ordinating operation of the liquid sampling and dispensing device, the rack advancement device, the tip moving device the rack feeding means and the rack ejection means. The tip (not shown) may be mounted in a holder 100 slidable between upper and lower positions on support rods (99'), Fig. 2 the tip holder 100 and a crossslide 115, 116 being connected by rods 105, 105 and the cross-slide being moved on movement of circular cam 118 in longitudinal slot 117 in the cross-slide cam 118 being mounted on a crank 90 which is itself mounted at 87-89 for rotation in either direction by shaft 85. The means for shifting the tip to and fro comprises cylindrical cam 216 having two cam tracks (246), 248, Figs. 10a, b, c (not shown), two spring-loaded cam followers 263 travelling in the lower parts of respective escape cylinders 259, 266 and dropping alternately into their respective tracks as toggle mechanism 268 operates and so providing to and fro movement longitudinally of the upper part of support rods (99 ), 99". The apparatus may include means for wiping the tip after use on freshly presented faces of a wiper tape which travels around reels (360, 361), 362, 366 which are mounted on a slotted wiper tape tray which can be drawn out of housing 16 to a position between the support rods 99', 99 and tubes T1, T2 Fig. 8 (not shown). The tape passes over each of two sponge rubber pads (137, 137') mounted on spring loaded arms (131), 131 one at each side of the tip, the pads being movable to press the tape against the tip as the tip is being retracted from a tube. The apparatus may include one or more auxiliary pipettes for introduction of reagent into the tubes.