Hypodermic needle assembly
First Claim
1. A needle-syringe assembly operable in a normal mode and convertible to a retraction mode, comprising:
- an elongated, generally cylindrical barrel forming a single cylindrical interior cavity and a hollow nozzle located at the distal end of said barrel and opening into the interior of said barrel;
a plunger slidably mounted in said barrel and forming a longitudinal cavity extending between the distal end and the proximal end of said plunger;
a needle holder for carrying a hollow needle on the distal end thereof, said needle holder being slidably mounted in said longitudinal cavity of said plunger, said needle holder detachably engaging said barrel with the distal portion of said needle holder disposed within said nozzle of said barrel during the normal mode;
means for maintaining the assembly in the selected mode; and
means for disengaging said needle holder from said barrel to switch the assembly from the normal mode to the retraction mode and for retracting said needle holder into said longitudinal cavity of said plunger such that said needle is concealed within the assembly.
1 Assignment
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Accused Products
Abstract
A needle-syringe assembly, operable in a normal mode and convertible to a retraction mode, comprises an elongated, generally cylindrical barrel, a plunger slidably mounted in the barrel, and a needle holder carrying a hollow needle on the distal end thereof. The barrel forms a hollow nozzle located at the distal end of the barrel. The plunger forms a coaxial cavity extending therethrough, and the plunger includes a helical slot exposing a proximal portion of the coaxial cavity. The needle holder is slidably mounted in the coaxial cavity of the plunger. During the normal mode, a distal portion of the needle holder is engaged within the nozzle by a taper lock. To switch from the normal mode to the retraction mode, the taper lock is disengaged by rotary movement of the plunger relative to the barrel. While preventing rotary movement of the needle holder relative to the barrel, continued rotary movement of the plunger causes a lateral arm of the needle holder to ascend through the helical slot so that the needle holder retracts into the coaxial cavity of the plunger and the needle is concealed.
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Citations
3 Claims
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1. A needle-syringe assembly operable in a normal mode and convertible to a retraction mode, comprising:
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an elongated, generally cylindrical barrel forming a single cylindrical interior cavity and a hollow nozzle located at the distal end of said barrel and opening into the interior of said barrel; a plunger slidably mounted in said barrel and forming a longitudinal cavity extending between the distal end and the proximal end of said plunger; a needle holder for carrying a hollow needle on the distal end thereof, said needle holder being slidably mounted in said longitudinal cavity of said plunger, said needle holder detachably engaging said barrel with the distal portion of said needle holder disposed within said nozzle of said barrel during the normal mode; means for maintaining the assembly in the selected mode; and means for disengaging said needle holder from said barrel to switch the assembly from the normal mode to the retraction mode and for retracting said needle holder into said longitudinal cavity of said plunger such that said needle is concealed within the assembly. - View Dependent Claims (2)
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3. A needle-syringe assembly, comprising:
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an elongated, generally cylindrical barrel forming a hollow nozzle located at the distal end of said barrel and opening into the interior of said barrel; a plunger slidably mounted in said barrel and forming a longitudinal cavity; a needle holder for carrying a hollow needle on the distal end thereof, said needle holder being slidably mounted in said longitudinal cavity of said plunger, said needle holder including a lateral arm extending laterally through said plunger cavity to said barrel; and a guide surface formed by said barrel and extending along a proximal end portion of said barrel for engaging the lateral arm of the needle holder and retracting the needle holder within the barrel in response to relative rotational movement between the barrel and the needle holder.
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Specification