DEVICE FOR WITHDRAWING A LIQUID SAMPLE FROM A CONTAINER OR FOR DISCHARGING A LIQUID SAMPLE INTO A CONTAINER, AND APPARATUS INCORPORATING THE DEVICE FOR WITHDRAWING LIQUID SAMPLES FROM RESPECTIVE ONES OF A PLURALITY OF CONTAINERS OR FOR DISCHARGING LIQUID SAMPLES INTO RESPECTIVE ONES OF A PLURALITY OF CONTAINERS

摘要

Apparatus (1) for withdrawing respective liquid samples from vials (2) which are closed by closure caps (4) penetratable by a pointed cannula comprises a plurality of racks (7) for accommodating the vials (2). A device (10) comprising a housing (25) is slideably carried on a gantry (9) which in turn is slideably carried on guide tracks (12) to provide two degrees of movement of the device (10) for selective alignment of the device (10) with the vials (2). An abutment member (43) which is vertically slideable in the housing (25) of the device (10) is driven by a second gearwheel (51) by a drive shaft (27) along which the housing (25) is slideably mounted through a first gearwheel (40) and a dog clutch (52). A cannula which is secured within a first gear rack (33) is driven upwardly and downwardly within the housing (25) by the first gearwheel (40) which is driven by the drive shaft (27). On engagement of the abutment member (43) with the closure cap (4) of the selected vial (2), the clutch (52) decouples the second gearwheel (51) from the first gearwheel (40) so that the cannula (28) is urgeable through the closure cap (4) into the vial (2) for withdrawing the liquid sample. The clutch (52) retains the second gearwheel (51) decoupled from the first gearwheel (40) until the cannula (28) has been withdrawn from the closure cap (4) in order to prevent displacement of the closure cap (4) during withdrawal of the cannula (28) therethrough.