Safety syringe needle device with interchangeable and retractable needle platform

A syringe comprising:

• a hollow, axially-elongated barrel having a needle end and an opposite end;
• an adapter removably mounted at the needle end of said barrel having a central fluid passage adapted for removable coupling to a hollow needle;
• an elongated plunger having a needle end portion and an opposite end portion and being axially movable in the hollow barrel;
• an adaptor engagement structure disposed at the needle end of the plunger and engageable with a mating connection engagement structure on the adapter in response to axial movement of the plunger toward the needle end of the barrel, said structures being cooperable, upon engagement, to cause relative rotation of the plunger and the adapter in response to such axial movement and to cause the adapter and any needle attached thereto to part from the end of the barrel in response to subsequent relative rotation of the plunger and the barrel and to be withdrawn into the interior of the barrel when the plunger is withdrawn from the distal end of the barrel;
• said opposite end portion of said plunger including connection structure sized and designed to cooperate with complementary connection structure included at the needle end of said barrel;
• and
• said plunger further including intermediate structure for detachably connecting said needle end and opposite end portions whereby said opposite end portion of the plunger when it is withdrawn from the needle end of the barrel can be detached and connected to the barrel needle end whether or not said adapter and attached needle have been withdrawn into the barrel interior.

A syringe comprising:

• a hollow, axially-elongated barrel;
• an adapter removably mounted at the distal end of said barrel and having a central fluid passage;
• a ferrule carrying a hollow needle and adapted for removable connection with the adapter adjacent the barrel end, with the hollow needle in communication with the central fluid passage of the adapter;
• a plunger axially movable in the hollow barrel;
• an adapter engagement structure disposed at the distal end of the plunger and engageable with a mating connection engagement structure on the adapter in response to axial movement of the plunger toward the distal end of the barrel, said structures being cooperable to cause (1) relative rotation of the plunger end and the adapter in response to such axial movement, and (2) the adapter and needle ferrule with the needle attached thereto part from the end of the barrel in response to subsequent relative rotation of the plunger and the barrel, thereby enabling the adapter and the needle ferrule with the needle attached thereto be withdrawn into the interior of the barrel when the plunger is withdrawn from the distal end of the barrel, leaving the distal end of the barrel open;
• and
• means cooperable with said distal end of said barrel for closing said open end thereof.

A syringe comprising:

• a hollow, axially-elongated barrel;
• an adapter carried by said barrel adjacent the distal end thereof and removable therefrom in response to rotation relative to the barrel, the adapter having a central fluid passage and adapted for removable coupling to a hollow needle;
• a plunger axially movable in the hollow barrel;
• adapter engagement structure disposed at the distal end of the plunger and engageable with a mating connection engagement structure on the adapter, said structures having alignment, drive and connective pairs of respective engagement surfaces, said alignment pair of surfaces being engageable and relatively movable to align and engage said drive surfaces one with the other thereby to enable subsequent rotation of the adapter relative to the barrel in response to relative rotation of the plunger and barrel, said connective surfaces being engageable response to substantially full axial insertion of said plunger in said barrel to connect the plunger and adapter one with the other, enabling the adapter and any attached needle to part from the end of the barrel and to be withdrawn into the interior of the barrel when the plunger is withdrawn from the distal end of the barrel, leaving said distal end of said barrel open;
• and
• means cooperable with said distal end of said barrel for closing said open end thereof.