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US 2006/0079840 A1Published application
Method and apparatus for controlling the speed of retraction of an automatically retracting needle
OwnerEdward Allardinventor
Life of this patent
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Abstract
A hypodermic syringe having an automatically retractable needle assembly, releasably activated upon voiding the syringe of injection fluid, with means for controlling the speed of retraction of the retracting needle upon activation of the needle assembly releasing mechanism, allowing the needle to be retracted into the barrel of the plunger for storage.
Claims5
In a hypodermic syringe:
- a fluid holding container;
- an actuable plunger within said fluid holding container for forcing the evacuation of any fluids contained therein;
- an automatically retractable spring loaded needle assembly attached to the distal end of the fluid holding container;
- a rupturable diaphragm sealing the innermost end of the plunger, whereby upon release of the retractable needle assembly, the proximal end of the needle ruptures the diaphragm and the needle is projected inside the plunger for storage;
- and
- means for controlling the speed of retraction of the retracting needle comprising a compressed conical spring, coupled to the retractable needle, which exhibits an increase in force as it propels the needle into the plunger for storage, whereby the speed of the needle is less at the initial release thereof than when the spring is fully extended.
3 more elements
A method of controlling the sped of retraction of an automatically retracting needle, including the steps of:
- actuating a plunger within a fluid holding container;
- expelling the fluid from the fluid holding container;
- releasing the retractable needle from a spring loaded needle assembly for storage in the actuating plunger upon contact with the distal end of the actuating plunger and a releasable engagement means functioning to hold said retractable needle in a state of equilibrium within said spring loaded needle assembly;
- controlling the speed of retraction of the retracting needle upon release from the spring loaded needle assembly, including the step of providing a conical spring for maintaining the needle in the spring loaded assembly, which spring exhibits the characteristic of an increasing retracting force after the initial release of the spring loaded needle.
1 more element
Dependencies are inferred from the claim text.