Syringe
AssigneeRoy H. Rengstorff
InventorDonald J. Highgate
Life of this patent
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Abstract
In a hypodermic syringe of the type comprising a chamber for liquid to be injected and a needle having a point for injection of the liquid, the syringe additionally includes, in contact with the liquid flow path through the syringe, a pre-stressed hydrophilic insert that, on hydration by contact with liquid, expands to block the flow path. The syringe is thus self-blocking; it can also be self-blunting, thus prevent reuse.
Claims4
A hypodermic syringe, comprising a chamber for liquid to be injected and a needle having a point for injection of the liquid, wherein the syringe includes, in contact with the liquid flow path through the syringe, a pre-stressed hydrophilic insert that, on hydration by contact with liquid, expands to block the flow path, the needle point is mounted on the insert, the point being deformed on hydration.
A hypodermic syringe comprising a chamber for liquid to be injected and a needle having a point for injection of the liquid, wherein the syringe includes, in contact with the liquid flow path through the syringe, a pre-stressed hydrophilic insert that, on hydration by contact with liquid, expands to block the flow path, the needle point is mounted on the insert, the point being covered by the insert on hydration.
Dependencies are inferred from the claim text.