Automatic fluid injector

A fluid injector for the measurement and injection of preselected quantities of fluid specimens into a media such as an inlet to an analytical instrument which comprises

• a fluid injector sub-assembly inclusive of
• a barrel,
• a hollow needle sealed and slidably mounted within the forward end of said barrel,
• a valve located at the rearward end of said barrel for opening and closing said barrel to the flow of fluid specimen through the barrel and hollow needle,
• a plate upon which said fluid injector sub-assembly is mounted and to which the hollow needle of the fluid injector sub-assembly is rigidly affixed,
• means associated with said fluid injector sub-assembly for movement of said assembly along a predetermined path for insertion of the needle thereof into the inlet of the analytical instrument, and
• means associated with the barrel of said fluid injector sub-assembly for movement of same relative to the hollow needle,
• whereby, on opening the valve of the fluid injector sub-assembly, the fluid specimen can be flowed through the barrel and needle to effectively purge and clean these members and, on closing the valve, a measured amount of fluid specimen can be trapped inside the barrel and needle, and then on insertion of the needle into the inlet of the analytical instrument, the fluid specimen can be injected by the relative forward movement of the barrel such that the needle moves rearwardly into the barrel to displace and cause ejection of the fluid specimen through the forward end of the needle and into the inlet.

A fluid injector for the measurement and injection of preselected quantities of fluid specimens into a media such as an inlet to an analytical instrument which comprises

• a fluid injector sub-assembly inclusive of
• a barrel,
• a hollow needle sealed and slidably mounted within the forward end of said barrel,
• a valve located at the rearward end of said barrel for opening and closing said barrel to the flow of fluid specimen through the barrel and hollow needle,
• a slide plate upon which said fluid injector subassembly is mounted and to which the hollow needle of the fluid injector sub-assembly is rigidly affixed,
• a base plate, which can constitute a portion of housing of said fluid injector, upon which said slide plate is slidably mounted,
• means mounted upon said base plate associated with said slide plate for producing the movement of said slide plate and fluid injector sub-assembly carried thereon along a predetermined path for insertion of the needle of the fluid injector sub-assembly into the inlet of the analytical instrument,
• means associated with the barrel of said fluid injector assembly for producing movement of said barrel relative to the needle of the fluid injector sub-assembly,
• an injector feed sub-assembly inclusive of
• a probe assembly constituted of one or a pair of hollow probes provided with communicating upper and lower openings mounted adjacent to said base plate in a generally vertical plane of orientation, including means for actuation and reciprocation of said probes, and means for transfer of a pressurized medium through a hollow probe, and
• a feed tray for transporting a fluid specimen contained in a vial, with a resilient, puncturable closure, into the path of a hollow probe for penetration of said closure by the probe whereby, on penetration of the puncturable closure of a vial by a probe, a pressurized fluid can be injected through the probe into the vial to pressurize the fluid specimen contained therein, the fluid specimen then transferred, when the valve of the fluid injector sub-assembly is open, from the vial via a hollow probe to the opening within said barrel, flowed through the barrel and needle to effectively clean these members and, on closing the valve, a measured amount of the fluid specimen can be trapped inside the barrel and needle, and then on thrust of the needle of the fluid injector sub-assembly into said inlet to the analytical instrument via activation of the means which produces movement of the slide plate, the fluid specimen can be injected by the relative forward movement of the barrel such that the needle moves rearwardly into the barrel to displace and cause ejection of the fluid specimen through the forward end of the needle and into the inlet of the analytical instrument.