Automatic engagement of a lead screw with a lead screw drive mechanism. A plunger driver used to move the plunger of a syringe is connected to the screw drive mechanism. A first detector provides a plunger signal indicating the presence of a syringe plunger in the plunger driver and a second detector...http://www.google.com.au/patents/US5106375?utm_source=gb-gplus-sharePatent US5106375 - Dynamic lead screw engagement and indicator
