Automatic fluid injector

Claim 1

In an apparatus for repetitively accurately measur-ing and injecting preselected quantities of fluid specimens into a media such as an inlet to an analytical instrument, the combination comprising a housing, which can be mounted adjacent an inlet leading into the analytical instrument, a block mounted within the housing, said block including a pair of communicated openings therethrough, a first opening of the pair extending through the block and housing and being located at such an angle with respect to the second that it can be aligned upon the inlet leading into the analytical instrument, a needle syringe mounted upon the forward end of a piston of a cylinder-piston unit affixed upon the housing, the needle of which is aligned upon the said second opening through the block within and through which the needle can be reciprocated by movement of the piston, said syringe including forward and rearward tubular portions separated one from the other by sealing means, the forward tubular portion of said syringe containing an exit port and providing a chamber for containing a predetermined quantity of fluid for injection via an opening within the dispensing end of the needle which is mounted on the front end of the said forward tubular portion, the rearward tubular portion of said syringe containing a plunger, the front end of which can be reciprocated within the chamber in the forward portion of the syringe, to provide in a first position a channel for the flow of fluid from the dispensing end of the needle through the said chamber to the exit port located therein, and in a second position to provide for the closure of the exit port to trap and contain a predetermined quantity of a fluid specimen for injection, and in a third position injection of the fluid specimen through the dispensing end of the needle. an injector feed unit including a hollow probe provided with communicating upper and lower openings mounted on the forward end of a piston of a cylinder-piston unit affixed upon the housing, said probe being aligned upon the said first opening through the block within and through which the probe can be reciprocated by movement of the piston, and extended through the said first opening, and means for transporting a fluid specimen contained in a vial, with a resilient, puncturable closure, below the said first opening and into the path of the hollow probe for penetration of said closure for pick-up of the fluid specimen via the lower opening of the probe and conveyance of same via the upper side opening of the probe into the opening of the needle and into the chamber of the syringe.