Patent ID: 6409703
Filing Date: 2002-06-25
Classification: A61M,Y10S

Abstract:
A safety syringe for intravenous injection comprising:a syringe means including a syringe cylinder having a sleeve portion eccentrically formed on a front portion of said syringe cylinder; a needle device detachably secured on said sleeve portion of said syringe cylinder and including: a hollow needle, a shank portion for externally connecting the hollow needle thereon and a locking head portion formed on a rear portion of said shank portion; and a plunger means slidably held in said syringe cylinder, having a plunger secured to a plunger rod and a biasing socket eccentrically recessed in said plunger for coupling said locking head portion of said needle device in said biasing socket when completing an injection, said plunger as coupled with said needle device operatively retracted into said syringe cylinder for tilting said needle without re-protruding said needle forwardly from said sleeve portion; the improvement which comprises: said sleeve portion having a plurality of sleeve ribs longitudinally formed on an inside wall in a sleeve hole formed through said sleeve portion; said shank portion having a plurality of shank ribs longitudinally formed on an outer surface of said shank portion for respectively engaging said sleeve ribs in said sleeve portion, whereby upon securing of said shank portion in said sleeve portion and upon rotation of said shank portion, said shank ribs on said shank portion will be engaged and locked by said sleeve ribs in said sleeve portion for preventing a further rotation of said shank portion, thereby allowing a smooth connection of said hollow needle on said shank portion on said syringe cylinder; and said syringe cylinder having at least a guiding means circumferentially formed on an inside wall of said syringe cylinder for slidably longitudinally guiding said plunger rod in said syringe cylinder to correspondingly align said biasing socket in said plunger with said locking head portion of said needle device for reliably coupling said plunger with said needle device upon completion of an injection.