MX173117B - SIMPLIFIED RETRAIBLE NEEDLE SYRINGE - Google Patents

Abstract

The present invention relates to a hypodermic syringe having a retractable needle, characterized in that it comprises a hollow cylindrical barrel of deformable plastic, semi-rigid, open at both ends and having a lip that projects inward at the lower end and tabs for the fingers on the upper end; a rigid, cylindrical needle holder mounted inside the barrel and seated on said lip and retained in place by friction sealing engagement between the outer diameter of said barrel and the inner wall of said barrel, said needle holder having an extension that it projects through the opening in the lower end of said barrel; Inner shoulders that extend inward over the inner wall of the barrel, directly above the carrier to help hold the carrier in place during use; a hypodermic needle mounted on the extension; a plunger slidably mounted on the barrel, through the open top end and defining a fluid chamber between the carrier and the plunger; a central hole through the carrier and the extension for fluid communication between the needle and the chamber; an enlarged hole in the carrier, close to the camera and coaxial with the center hole; an arrow extending from the lower end of the plunger; a mace on the lower end of the arrow, adapted to lock inside the enlarged hole; and expansion means on the plunger to deform the shoulders and release the carrier when said hub engages with the enlarged hole.