Syringe having needle isolation features
First Claim
1. A hypodermic syringe comprising:
- a barrel having opposed proximal and distal ends and a fluid-retaining chamber extending therebetween, said distal end of said barrel having a passageway extending therethrough and communicating with said chamber;
a stopper slidably disposed in fluid-tight engagement in said chamber, said stopper having opposed proximal and distal ends, an aperture extending through said stopper from said proximal end to said distal end and defining an axial length;
a plug having a head positioned in said aperture of said stopper and a tail extending distally from said head and projecting beyond said distal end of said stopper, said aperture including a sealing portion along its length, said head being in fluid-tight engagement with said sealing portion;
means for allowing fluid flow between said sealing portion of said aperture and said tail so that fluid can flow through said aperture when said tail is positioned within said sealing portion;
whereby distally directed fluid pressure in the chamber causes said stopper and said plug to move simultaneously until said tail of said plug engages said distal end of said barrel, whereafter the fluid pressure urges said stopper distally independent of said plug to disengage said head of said plug from said sealing portion of said aperture so that said tail is positioned within said sealing portion of said aperture and to permit fluid flow between said tail and said sealing portion toward said passageway of said barrel.
1 Assignment
0 Petitions
Accused Products
Abstract
A syringe having structure to isolate fluid from the distal end of the syringe includes a barrel with a chamber therein. A stopper is slidingly disposed in the chamber and is provided with an aperture extending axially therethrough. A plug includes a head releasably engaged in a sealing portion of the aperture of the stopper. A rigid tail extends distally from the head and through the aperture in the stopper and projects outwardly from the distal end of the stopper. The tail is long enough so that it can be used to move the head out of the sealing portion of the aperture by applying force to the distal end of the tail. The tail has a cross-sectional shape which defines at least one fluid channel between the tail and the sealing portion of the stopper to allow fluid to flow from the chamber through the aperture in the stopper and out of the distal end of the barrel.
39 Citations
17 Claims
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1. A hypodermic syringe comprising:
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a barrel having opposed proximal and distal ends and a fluid-retaining chamber extending therebetween, said distal end of said barrel having a passageway extending therethrough and communicating with said chamber; a stopper slidably disposed in fluid-tight engagement in said chamber, said stopper having opposed proximal and distal ends, an aperture extending through said stopper from said proximal end to said distal end and defining an axial length; a plug having a head positioned in said aperture of said stopper and a tail extending distally from said head and projecting beyond said distal end of said stopper, said aperture including a sealing portion along its length, said head being in fluid-tight engagement with said sealing portion; means for allowing fluid flow between said sealing portion of said aperture and said tail so that fluid can flow through said aperture when said tail is positioned within said sealing portion; whereby distally directed fluid pressure in the chamber causes said stopper and said plug to move simultaneously until said tail of said plug engages said distal end of said barrel, whereafter the fluid pressure urges said stopper distally independent of said plug to disengage said head of said plug from said sealing portion of said aperture so that said tail is positioned within said sealing portion of said aperture and to permit fluid flow between said tail and said sealing portion toward said passageway of said barrel. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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Specification