Single-use syringe with retractable needle
First Claim
1. A single-use syringe comprising a tubular body, a plunger slidable in sealed relationship within said tubular body, a needle mounted in said tubular body at a first axial end thereof and being movable between a first, safe position and a second, working position whereat said needle is retracted into and extended from said body, respectively, through an opening of the body, a first socket formed in said tubular body, needle guide means carried by said needle and received in said first socket for guiding said needle through said opening, an expansible and contractible retaining member attached to one end of the needle extending inside said tubular body, spring biasing said retaining member and said needle toward said retracted safe position, at least one step defined in said tubular body at a set distance from said first end, said step being overridden by said retaining member as said needle is moved from the first to the second position, an expander device for expanding the retaining member carried removably on said plunger and received and held in a second socket formed in said retaining member so as to expand said retaining member upon overriding the step to hold the needle in the working position with said retaining member abutted against the step, means on said plunger for dislodging the expander device from said socket means on completion of a working stroke of the plunger so as to disengage the retaining member from the step and allow said spring to return the needle to the first retracted position, and means for misaligning said needle, upon return to said first retracted position, with respect to said opening wherein reuse of said syringe is prevented.
2 Assignments
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Accused Products
Abstract
The syringe has a tubular body slidably housing a plunger connected to a needle, movable between a first, safe position and a second, working position, respectively retracted into and extended from the body, and a spring biasing the needle toward its retracted position. An expansible retaining member is attached to one end of the needle and overrides a step, defined on the tubular body, as the needle is moved from the first to the second position. An expander device is carried movably on the plunger and adapted to be received and held in a socket formed in the retaining member to expand it and hold the needle in the working position. An annular rib is provided on a lug connected to the plunger for dislodging the retaining member from the step and release the needle, which is returned by the spring to its first position, out of sight inside the tubular body.
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Citations
14 Claims
- 1. A single-use syringe comprising a tubular body, a plunger slidable in sealed relationship within said tubular body, a needle mounted in said tubular body at a first axial end thereof and being movable between a first, safe position and a second, working position whereat said needle is retracted into and extended from said body, respectively, through an opening of the body, a first socket formed in said tubular body, needle guide means carried by said needle and received in said first socket for guiding said needle through said opening, an expansible and contractible retaining member attached to one end of the needle extending inside said tubular body, spring biasing said retaining member and said needle toward said retracted safe position, at least one step defined in said tubular body at a set distance from said first end, said step being overridden by said retaining member as said needle is moved from the first to the second position, an expander device for expanding the retaining member carried removably on said plunger and received and held in a second socket formed in said retaining member so as to expand said retaining member upon overriding the step to hold the needle in the working position with said retaining member abutted against the step, means on said plunger for dislodging the expander device from said socket means on completion of a working stroke of the plunger so as to disengage the retaining member from the step and allow said spring to return the needle to the first retracted position, and means for misaligning said needle, upon return to said first retracted position, with respect to said opening wherein reuse of said syringe is prevented.
Specification