04994034 is referenced by 175 patents and cites 4 patents.

A hypodermic injection system with a retractable needle wherein the needle retracts within the interior cavity of a syringe plunger, so that the needle is safely and confinedly held within the plunger for ease of handling and transport, while remaining safely therein. A cylindrical spring housing has resilient fingers which can capture a coiled spring which biasly holds a needle holder against the retaining force of the resilient fingers. The plunger has a frangible end, which, when engaging the resilient fingers under a pre-determined amount of force, dissociate while remaining inwardly-tapered shoulders spread the resilient fingers, allowing the coiled spring to eject the needle and its holder into the interior cavity of the syringe plunger.

Title
Retractable needle hypodermic syringe system
Application Number
7/378275
Publication Number
4994034
Application Date
July 11, 1989
Publication Date
February 19, 1991
Inventor
Thor R Halseth
1223 Village Ct., Simi Valley, 93065
CA, US
Michael J Botich
1307 Hanover Ct., Ventura, 93003
CA, US
Agent
Cislo & Thomas
IPC
A61M 5/24
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