GB863907A - Multiple injection inoculator instrument - Google Patents

Abstract

863,907. Surgical syringes. WALKER, G. W., ZIHERL, F., and ZIHERL, L. A. Jan. 21, 1958, No. 2029/58. Class 81 (2). [Also in Group XXVIII] A surgical syringe has a slidable ejector 22, means for projecting the ejector to eject a prescribed amount of liquid from a discharge chamber C, means for retracting the ejector and a metering chamber 58 which receives a prescribed amount of liquid from a reservoir 66 when the ejector is in its forward position and from which liquid is displaced to the discharge chamber through a passage having means 25 for preventing counterflow when the ejector is retracted. An ampoule C is received in a plunger guide 17 mounted on the syringe barrel 12 and is secured by an apertured cap 19 having a concave end. A plunger 22 having an axial bore 23 with a ball check valve 25 terminates in an axially bored nose 33 having ports 37 communicating with the ampoule C. The plunger 22 is slidable in bores 13, 14, 15 in the barrel 12 and carries a piston 26 which is prevented from rotating axially by projections 28 riding in keyways 29. A spring 48 surrounds the rear end of the plunger 22 and is held between the piston 26 and a cap 43 closing the barrel 12 at the rear. The plunger 22 extends through the cap 43 and is slidable in a sleeve 40 which also extends rearwardly through the cap 43. A pump piston 50 is movable against a spring 57 in the sleeve 40. In the sleeve 40 and formed between the rear end of the plunger 22 and the pump piston 50 is the metering chamber 58 which is supplied, as the plunger is projected, with medicament from a bottle 66 supported on the barrel 12, a needle 67 communicating with the interior of the bottle 66 and an axially bored fitting 69 with a ball valve 72 being interposed between the bottle 66 and an opening in the sleeve 40. Secured to the barrel 12 is a butt portion 11 containing an hydraulic fluid reservoir 75 from which fluid is pumped into the bore 14 of the barrel 12 by a piston 78 reciprocated by a pivoted handle 80. Fluid entering the bore 14 of the barrel 12 moves the piston 26 rearwardly to compress the spring 48 and retract the plunger 22, medicament then flowing from the metering chamber 58 through the plunger 22 to the ampoule C. On pressing a valve stem 94 in the butt portion 11, a ball valve 96 is opened so that hydraulic fluid returns to the fluid reservoir 75, thus releasing the spring which forces the piston 26 and the plunger 22 forwardly to eject medicament from the ampoule C through a fine aperture 109. As the plunger 22 moves forwardly the pump chamber 58 is enlarged and refilled with medicament from the bottle 66. The piston 50 in the sleeve 40 is manually reciprocated when the syringe is first used to transfer medicament from the bottle 66 to the metering chamber and supply the ampoule C with its initial charge. Reference has been directed by the Comptroller to Specification 798,826.