Patent ID: 6387079
Filing Date: 2002-05-14
Classification: A61M,Y10S

Abstract:
A safety syringe, comprising a barrel, a hub, a cap and a plunger;said barrel including a diameter-reduced neck portion extending to an open front end portion, said open front end portion having a radially inwardly inclining inner peripheral wall forming a first shoulder portion between said inner peripheral wall of said open front end portion and an inner peripheral wall of said neck portion, said inner peripheral wall of said neck portion being gradually diametrically reduced from said first shoulder portion to a rear end of said neck portion; said hub having (a) a cannula fixed to a front end thereof, (b) a second shoulder portion circumscribing a middle portion of said hub, and (c) a radially extending channel formed adjacent a rear end of said hub and defining a pair of diametrically opposed openings therein to serve as receiving holes, an outer peripheral wall portion having a gradually reduced diameter between said second shoulder portion and said rear end of said hub; said cap removably covering said cannula and a portion of said hub; and, said plunger being removably disposed in said barrel for injecting a medical liquid from within said barrel into a patient's body through said cannula, said plunger being an elongated member inserted into said barrel via an opening provided at a rear end of said barrel, said plunger having a stopper provided around a front end thereof with an engaging cone projecting forward from a front end of said stopper, said engaging cone being formed with a small slit extending radially from a pointed end of said engaging cone to a peripheral edge thereof, whereby when said hub is assembled into said neck portion of said barrel, said first and second shoulder portions are disposed in contact with each other to (a) provide a first airtight contacting surface joint therebetween, and (b) prevent said hub from moving out of said neck portion of said barrel, and said outer peripheral wall portion of said hub engaging said inner peripheral wall of said neck portion in substantially conformed manner to form a second airtight contacting surface joint therebetween.