Patent ID: 6626863
Filing Date: 2003-09-30
Classification: A61M

Abstract:
A safety syringe comprising a barrel having a needle end, a plunger end, and sides extending therebetween;a plunger slidably disposed in said barrel, said plunger having a washer end positioned closest to said needle end of said barrel, said washer end configured to create a substantially fluid tight seal with said barrel sides; a needle, having a sharp end and a barrel end, mounted in said barrel such that said sharp end of said needle extends beyond said needle end of said barrel; a sheath slidably disposed over said needle, said sheath having an exposed position wherein said sharp end of said needle is not covered by said sheath and a covered position wherein said sharp end of said needle is covered by said sheath; at least one arm having a sheath end facing said sheath and a plunger end facing said plunger, said arm operatively connecting said sheath and said plunger whereby said sheath may be moved from said exposed position to said covered position upon depression of said plunger; and a locking mechanism configured to secure said sheath in said covered position comprising: a bar positioned within said barrel transverse to said sides of said barrel; a first tooth positioned on said arm, said first tooth having a leading edge facing said sharp end of said needle and a trailing edge facing said plunger end of said barrel; a second tooth positioned on said arm between said first tooth and said plunger end of said arm, said second tooth having a leading edge facing said sharp end of said needle and a trailing edge facing said plunger end of said; said first tooth and said second tooth positioned to encounter said bar when said sheath is advanced from said exposed position to said covered position, said first tooth configured to pass over said bar when force is applied to said arm in the direction of said sharp end of said needle, said trailing edge of said first tooth configured to prevent said first tooth from passing over said bar when force is applied to said arm in the direction of said plunger end of said barrel, said second tooth configured to prevent said second tooth from passing over said bar when force is applied to said arm in the direction of said sharp end of said needle, whereby said bar may be locked between said first tooth and said second tooth; and wherein said needle, said sheath, said bar, said arm, said first tooth and said second tooth are configured so that said sheath is in said covered position when said bar is positioned between said teeth, whereby said sheath may be locked in said covered position by advancing said teeth until said bar is positioned between said teeth.