The fluid injection apparatus for use with the syringe includes an injector and a pressure jacket assembly associated with the injector. The injector includes a housing defining a central opening and a drive piston extendable through the central opening for imparting motive forces to a syringe plunger...http://www.google.ca/patents/US7361156?utm_source=gb-gplus-sharePatent US7361156 - Pressure jacket system with pivotal locking members
