Extracting a quantity of liquid from a closed container by driving a cannula having a passage the length of the cannula and a groove a partial length of the cannula through the closure of the container until the groove establishes communication between a pressurized chamber and the container, thereby...http://www.google.com.au/patents/US6077713?utm_source=gb-gplus-sharePatent US6077713 - Method and apparatus for extracting liquid samples from a closed container
