Abstract: A syringe includes an elongate barrel having an open proximal end and a distal end that includes a fitting. It also has a plunger having a proximal end and a distal end, sized for slidable movement within the barrel thereby defining a chamber within the barrel. The plunger also has an elongate cavity therewithin that has a closed proximal end and an open distal end. The open end of the plunger is closed by a selectively releasable closure. The syringe has a hub that attaches to the barrel with a fitting conjugate to the fitting. The hub includes an elongate needle having a proximal end, a distal end and a fluid path therethrough. The needle is positioned in the passageway for slidable movement between a first position wherein the fluid path of the needle is in fluid communication with the chamber and a second position. The needle has a mount at its proximal end forming a seal with the chamber when the needle is in the first position.

Abstract: A needle cannula is surrounded by a collapsible sheath. The entire sheath can be retracted proximally on the needle cannula into a position where the distal tip of the needle cannula is visible to ensure optimal positioning and orientation for an injection. A spring may urge the entire sheath toward its distal position, and a lock may permit releasably retention of the entire sheath in its retracted proximal position.

Abstract: A needle cannula is surrounded by a collapsible sheath and a spring that is expandable and retractable independent of the sheath. A tip guard is mounted to either the distal end of the sheath or the distal end of the spring. The tip guard is movable to protectively cover the tip of the needle cannula as the spring expands independently of the sheath. Proximally directed forces on the tip guard will merely urge the tip guard into tighter protective engagement with the distal tip of the needle cannula without exposing the needle cannula. However, the needle cannula can intentionally be re-exposed by merely collapsing the spring in a proximal direction.

Abstract: A safety needle syringe includes a barrel having an inside surface defining a chamber, an open proximal end and a distal end. A movable needle carrier is positioned in fluid-tight engagement with the inside surface of the barrel and includes a distal end, a proximal end and a passageway there through in fluid communication with the chamber. A needle cannula projects outwardly from the distal end of the carrier and includes a lumen in fluid communication with the passageway. A plunger assembly is slidably positioned in fluid tight engagement with the inside surface of the barrel. Structure is providing for allowing the distal end of the plunger to engage the carrier for allowing axially directed and rotational forces applied to the proximal end of the plunger to be transmitted to the carrier.