Patent ID: 6117107
Filing Date: 2000-09-12
Classification: A61M

Abstract:
A safety syringe for intravenous injection, comprising:a barrel having a conically shaped front portion and an opposing rear portion with an outwardly extended flange formed thereat, said barrel having a bore formed therein and said rear stem having an opening formed in open communication with said bore, said barrel having a pair of guide strips formed on a wall surface interior to said bore and a reduced tubular outlet eccentrically disposed on said conically shaped front portion and in open communication with said bore;a needle unit having a spindle shaped needle holder releasably coupled to said tubular outlet and a cannulated needle affixed to said needle holder to extend from a first end thereof, said needle holder having a second end and a connecting stem extending therefrom, said connecting portion having an inclined bottom surface and an opening extending from said bottom surface with an arrowhead shaped mortise formed in said opening and inclined with respect to an axis of said needle;a plunger slidingly disposed in said bore of said barrel, said plunger having (a) a plunger head having an upper conical surface, (b) an arrowhead shaped tenon eccentrically disposed on said plunger head and extending from said upper conical surface thereof in aligned relationship with said mortise of said connecting stem, (c) a sealing ring circumscribing said plunger head, and (d) a supporting plate disposed beneath said plunger head and supporting said sealing ring, said supporting plate having a pair of guide notches formed therein for respectively receiving said pair of guide strips therein, said plunger being displaced toward said front portion of said barrel to express a fluid from said barrel and engage said mortise with said tenon, subsequent displacement of said plunger toward said rear portion of said barrel thereby displaces said needle unit into said bore of said barrel and said needle set being offset with respect to said tubular outlet by cooperation between (i) said inclined bottom surface of said connecting portion, (ii) said conical surface of said plunger head, and (iii) said inclined mortise; and, a tubular needle cap having a closed distal end for insert into said tubular outlet subsequent to said needle unit being displaced into said bore.