Single-use syringe

A single-use syringe having a cylindrical body, piston means mounted in said body and movable along a longitudinal central axis therein in a respective fluid suction stroke and an opposite fluid ejection stroke seal means adjacent one end of the said piston means for fluid sealing between said body and said piston means, one or more cutting arms mounted adjacent said one end of said piston means for pivotal movement about one or more pivot axes transverse to said longitudinal axis between a retracted position when said piston means is moved on a suction stroke in said body and a cutting position when said piston means is moved on an ejection stroke for cutting an opening in a wall portion of said body, said pivot axes being in a fixed position relative to said piston means each said cutting arm having a pointed free end portions passing through a side portion of said seal means firmly securing said arm against pivotal movement penetrating said body during a suction stroke, each of said arms having a bevelled, stop surface engaging said piston means to prevent pivotal movement in one direction for allowing said arms to move along the inside of said cylindrical body during a stroke without cutting suction action, each of said arms having a sharpened front edge end section forming a cutting blade which is pivoted to a cutting position as said piston means moves on an ejection stroke inside of said cylindrical body to penetrate and cut through said wall of the said cylindrical body rendering said syringe unusable for further use after said ejection stroke is stopped.