Automatic fluid injector

In a fluid injector useful for the measurement and injection of preselected quantities of a fluid specimen into a medium such as an inlet to an analytical instrument the combination comprising

• (A) a syringe inclusive of a barrel into which a fluid specimen can be loaded, a needle mounted on the forward end of the barrel, and means for the displacement of the fluid specimen from said barrel, via the dispensing end of the needle into said inlet,
• (B) an injector feed assembly inclusive of a probe sub-assembly which includes a pair of telescoping frames, a first frame provided with a base, an opening through said base, a plurality of shafts, spaced apart and parallelly oriented one with respect to the other supported upon said base, a second frame provided with a plurality of openings corresponding in number and orientation wtih the shafts on the base of said first frame within which said shafts of said first frame are guided and slidably mounted upon said first frame, locking means for locking together said first frame and said second frame so that said frames can be moved simultaneously, and unlocked such that said second frame can be telescoped upon said first frame, a tubular barrel mounted within and sealed inside said second frame the central axis of which is aligned upon the central axis of the opening within the base of said first frame, a gas inlet to the tubular barrel mounted and sealed within said second frame, a pair of concentrically mounted hollow needles, an outer rigid tubular needle of relatively large inside diameter mounted, reciprocably movable, and sealed within said tubular barrel of said second frame, an inner flexible tubular needle, a terminal end and at least an adjacent portion thereof which is contained within the opening through said outer rigid tubular needle, the inner flexible needle being affixed to said second frame and of sufficiently small outside diameter to form an annulus between the external surface of said inner flexible tubular needle and the internal surface of said outer rigid tubular needle, said annulus being communicated with the tubular barrel mounted within and sealed inside said second frame said with the gas inlet to said-tubular barrel, while the opposite end of said inner flexible tubular needle is communicated with the barrel of said syringe,
• (C) a magazine for transporting one or more fluid specimen-containing septum sealed vials for pick up therefrom of a fluid specimen by the injector feed probe sub-assembly when the second frame in a first stage is moved concurrently with said first frame to thrust the outer hollow rigid needle through the septum of said specimen sealed fluid specimen-containing vial, and in a second stage of movement the second frame is telescoped upon said first frame to thrust and extend the inner hollow flexible needle to the very bottom of said vial, gas injected via the gas inlet to the tubular barrel and passed via the annulus between the external surface of said inner tubular needle and the internal surface of said outer rigid tubular needle to pressurize the fluid-specimen within said vial such that essentially all of the fluid specimen within said vial can be conveyed via the iner flexible needle to the barrel of the syringe.

In a fluid injector useful for the measurement and injection of preselected quantities of a fluid specimen into a medium such as an inlet to an analytical instrument wherein there is included the combination of (A) a syringe inclusive of a barrel into which a fluid specimen can be loaded, a needle mounted on an end of the barrel, and means for the displacement of the fluid specimen from said barrel via the dispensing end of the needle into said inlet, (B) an injector feed assembly comprised of a probe sub-assembly inclusive of a pair of concentrically mounted hollow needles for the pick up of said fluid specimen for filling the barrel of said syringe, and (C) a magazine for transporting one or more fluid specimen-containing septum sealed vials for pick up of fluid from said vials by the pair of hollow needles of said probe sub-assembly by said injector feed assembly for delivery to the barrel of said syringe via thrust of the hollow needles of said probe sub-assembly through the septum of a vial, the contents of the vial pressurized by delivery of gas from a source through an annulus between the exterior surface of said inner hollow needle and the interior surface of said outer hollow needle of the pair of concentrically mounted hollow needles of said probe sub-assembly to produce flow of fluid specimen from said vial through the probe sub-assembly to the barrel of the syringe,

• the improvement wherein the pair of concentrically mounted hollow needles of said probe sub-assembly of the injector feed assembly (B) is comprised of the combination of
• (i) an outer rigid tubular needle of relatively large inside diameter, an end of which is directly affixed to said injector feed assembly, and
• (ii) an inner flexible tubular needle, a terminal end and at least an adjacent portion thereof of which is contained within the bore of said outer rigid tubular needle and is of sufficiently small outside diameter to form an annulus between the external surface of said inner flexible tubular needle and the internal surface of said outer rigid tubular needle, while the opposite end of said inner flexible tubular needle is communicated with the barrel of said syringe,
• (iii) a pair of telescoping frames, a first frame provided with a base, an opening through said base, a plurality of shafts, spaced apart and parallelly oriented one with respect to the other supported upon said base, a second frame provided with a plurality of openings corresponding in number and orientation with the shafts on the base of said first frame within which said shafts of said first frame are guided and slidably mounted, locking means for locking together said first frame and said second frame and for unlocking said first frame from said second frame such that said second frame can in a first stage be locked to said first frame and moved simultaneously therewith and, in a second stage unlocked from said first frame and telescoped upon said first frame, a tubular barrel mounted and sealed within said second frame the central axis of which is aligned upon the central axis of the opening within the base of said first frame, a gas inlet to the tubular barrel, the outer rigid tubular needle of the pair of hollow needles of said probe sub-assembly being mounted, reciprocably movable and sealed within said tubular barrel of said second frame, while the inner flexible tubular needle of the pair of needles, is affixed to said second frame, passed through said tubular barrel and movable with said second frame such that it is reciprocably projectable into and out of the outer rigid hollow needle of the probe pair, the inner flexible tubular needle being shielded within the outer rigid tubular needle
• whereby in said first stage of movement said frames are locked one to the other and moved together in unison, the inner flexible needle being transported within and shielded by the outer rigid needle of the concentric needles of the probe assembly to pentrate the septum of a specimen-containing vial by said outer needle, and thereafter in said second stage of continued movement the frames are unlocked one from the other and the second frame is telescoped upon said first frame so that the inner flexible needle is moved outside said outer rigid hollow needle and extended to the very bottom of said fluid specimen-containing vial such that on pressurization of the contents of the vial with a gas delivered via the annulus of the needles of the proble sub-assembly essentially all of the fluid specimen can be removed from said vial, picked up by the probe sub-assembly, delivered to the barrel of the syringe, and injected into a medium via the dispensing end of the needle of the syringe.