TW200610553A - Retractable type safety syringe structure - Google Patents

Abstract

This invention is related to a retractable type safety syringe structure which mainly comprises an outer tube, a lid sleeve, a joint base, a push rod and a needle. Among them, the outer tube is a hollow tube body; the front end of the outer tube body fits the lid sleeve, the cavity of the lid sleeve also fits the joint base and the joint base connects with the needle. Also the push rod is installed in the cavity of the outer tube which provides to draw out the injection solution or to inject and pulls the joint base together with the needle into the inside part of the outer tube. The lid sleeve covers the front end of the outer tube cavity and has inner double threads wherein the other side of the tube body connects with a sealed ring by hot melting to make it be sealed up and leakage preventing. The joint base is composed of a projecting small tube and a base body installed in the cavity of the lid sleeve in which the base body has a buckle mechanism of wedging with the push rod to provide the pull rod to pull the joint base to retract into the inside part of the outer tube. This invention takes advantage of the detachable components of the outer tube, the lid sleeve and the joint base. When operating the syringe, the needle base is tightly covered on the projecting small tube by clockwise gyrating the needle by hands, and by dragging the pull rod to draw out the injection solution to directly inject or to be covered by needle lid again, then after detaching the needle and changing a new needle, proceed to inject again. When the pull rod is pulled to the end point of the route, because of the pull rod wedging with the buckle mechanism of the base body of the joint base, the pull rod draws the joint base together with the needle to retract in the inside part of the outer tube, and the object of guarding against needle is achieved.