Safety syringe needle device with interchangeable and retractable needle platform

A syringe comprising:

• (a) a hollow axially-elongated barrel for containing fluid to be injected by the syringe;
• (b) an adapter removably mounted at the distal end of said barrel, having a portion projecting into the barrel toward its proximal end and having a fluid passage in communication with the interior of the barrel;
• (c) a ferrule carrying a hollow needle and adapted for removable connection with one of the distal barrel end and the adapter adjacent the barrel end, with the hollow needle in communication with the fluid passage of the adapter;
• (d) a plunger axially movable in the hollow barrel between retracted and extended positions;
• (e) an adapter engagement structure disposed at the distal end of the plunger and engageable with a mating connection engagement structure on the projecting adapter portion 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 to 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the plunger and the barrel, thereby enabling the adapter and the needle ferrule with the needle attached thereto to be withdrawn into the interior of the barrel when the plunger is withdrawn from the distal end of the barrel;
• and
• (f) a needle guard removably connected to one of said ferrule and said distal end of said barrel;
• and
• (g) means connected to said barrel and said needle guard to indicate attempted movement of said needle guard and said barrel relative to one another.

A syringe comprising:

• (a) a hollow axially-elongated barrel;
• (b) 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 fluid passage and adapted for removable coupling to a hollow needle;
• (c) a plunger axially movable in the hollow barrel between extended and retracted positions;
• and
• (d) adapter engagement structure disposed at the distal end of the plunger and engageable with a mating connection engagement structure on the adapter and projecting into the interior of said hollow barrel, 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 in 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;
• and
• means connecting between said barrel and said plunger in the retracted position of said plunger to indicate attempted movement of said barrel and said plunger relative to one another.

A syringe comprising:

• (a) a hollow axially-elongated barrel for containing fluid to be injected by the syringe;
• (b) an adapter removably mounted at the distal end of said barrel and having a fluid passage in communication with the interior of the barrel;
• (c) a ferrule carrying a hollow needle and adapted for removable connection with one of the distal barrel end and the adapter adjacent the barrel end, with the hollow needle in communication with the fluid passage of the adapter;
• (d) a needle guard releasably connected with one of said ferrule and said distal barrel end;
• (e) a plunger axially movable in the hollow barrel between retracted and extended positions relative to said barrel;
• and
• (f) means connecting between said barrel and said needle guard and between said barrel and said plunger in the retracted position of said plunger to indicate attempted removal of said needle guard from said one of said ferrule and said distal barrel end and movement of said plunger relative to said barrel from said plunger retracted position.