Patent ID: 6248094
Filing Date: 2001-06-19
Classification: A61M

Abstract:
A syringe comprising:an elongated housing having a front end for attachment of a needle and a rear end for insertion of a plunger, said housing defining a substantially hollow interior portion between said front and rear ends;a carpule disposed in said housing comprising a tube having first and second open ends, said carpule including a needle-retaining member slidably disposed within said first open end and a fluid-expelling member disposed within said second open end, said needle-retaining member and said fluid-expelling member each forming a fluid-tight seal with an interior surface of said tube to define a fluid chamber between said members, and said carpule disposed within said substantially hollow interior portion of said housing to position said needle-retaining member adjacent said front end of said housing;a needle having a leading end normally projecting from said front end of said housing for injecting a patient and a trailing end extending into said front end of said housing and through said needle-retaining member to draw fluid from said fluid chamber;a plunger having a gripping end and an opposing penetrating end, said penetrating end securely engaging said fluid-expelling member to push said fluid-expelling member toward said first end of said carpule and expel substantially all said fluid within said fluid chamber through said needle; andattachment means connected to said fluid-expelling member within said fluid chamber, said attachment means securely engaging said needle-retaining member as said plunger pushes said fluid-expelling member to said first end of said carpule whereby retraction of said plunger toward said second open end of said carpule causes retraction of said needle-retaining member away from said open end and retraction of said needle into said carpule.